AC Energy Research Articles

Performance evaluation and comparative study of three 52-kW PV plants in India: a case study

Developing countries like India are rapidly transitioning from traditional energy sources to sustainable energy sources, due to the increase in demand and the depletion of fossil fuels. Grid-connected photovoltaic (PV) systems attract many investors, organizations, and institutions for deployment. This article studies and compares the performance evaluations of three 52-kW PV plants installed at an educational institution, SRMIST (SRM Institute of Science and Technology), in Tamil Nadu, India. This site receives an annual average temperature of 28.5°C and an average global horizontal irradiation of 160 kWh/m2/m. The prediction model for the 52-kW power plant is obtained using solar radiation, temperature, and wind speed. Linear regression model-based prediction equations are derived using the Minitab 16.2.1 software, and the results are compared with the real-time AC energy yield acquired from the three 52-kW plants for the year 2020. Furthermore, this 52-kW plant is designed using PVsyst V7.1.8 version software. The simulation results are compared with the energy yield from the plants in 2020 to identify the shortfall in the plant performance. The loss analysis for the plant is performed by obtaining the loss diagram from the PVsyst software. This study also proposes a methodology to study the commissioned PV plant's performance and determine the interaction between variables such as direct and diffused solar radiations, air temperature, and wind speed for forecasting hourly produced power. This article will motivate researchers to analyze installed power plants using modern technical tools.

Greek Cross (+) Aggregate

The independent discovery of dye aggregate by Jelley and Scheibe marked the beginning of a spectacular development in the field of aggregate photophysics.1 Subsequent research warranted an exceptional model for defining the exciton interactions in aggregates, proposed by Kasha and Davydov independently, which was later modified by incorporating the short-range excitonic coupling.2-3 Apart from the well-studied H- and J-aggregate, achieving the orthogonally cross-stacked assembly possessing null excitonic interactions remained elusive. The first crystalline evidence for the chromophoric Greek cross (+) assembly exhibiting monomer-like optical properties was reported in 2018.5 The emergent photophysical properties of the crafted Greek cross (+) architectures were explored using both experimental and computational techniques for understanding the aggregate properties beyond Kasha’s model.6-7 The manifestation of selective hole transfer coupling in the edge-to-edge arranged Greek cross (+) perylenediimide (PDI) dimer resulted in ultrafast dissociation of null exciton and evolution of the charge-separated state in a polar solvent, providing a way forward in the fundamental understanding of null aggregates.8 References 1 (a) Jelley, E. E.; Nature, 1936, 138, 1009– 1010; (b) Scheibe, G.; Angew. Chem., 1937, 50, 212– 219; (c) Ramakrishnan, R.; Niyas, M. A.; Lijina, M. P.; Hariharan, M.; Acc. Chem. Res., 2019, 52, 3075−3086. 2 (a) Kasha, M.; Rawls, H. R.; El-Bayoumi, M.; Pure Appl. Chem., 1965, 11, 371–392; (b) Davydov, A. S.; Sov. Phys. Uspekhi; 1964, 7, 145– 178, 3 Hestand, N. J.; Spano, F. C.; J. Chem. Phys. 2015, 143, 244707. 4 Sebastian, E.; Philip, A. M.; Benny, A.; Hariharan, M.; Angew. Chem. Int. Ed., 2018, 57,15696- 15701. 5 Lijina, M. P.; Benny, A.; Ramakrishnan, R.; Nair, N. G.; Hariharan, M.; J. Am. Chem. Soc., 2020, 142, 17393-17402. 7 Benny, A.; Ramakrishnan, R.; Hariharan, M., Chem. Sci., 2021, 12, 5064– 5072. 8 Sebastian, E.; Hariharan, M.; J. Am. Chem. Soc., 2021, 143, 13769–13781; (b) Sebastian, E.; Hariharan, M.; ACS Energy Lett., 2022 , 7, 696−711. Figure 1

Magnetically-Induced Buoyancy for Efficient Electrochemical Oxygen Production in Microgravity

The realization of long-term space travels and the establishment of a lunar research platform are challenged by the lack of technological device architectures for efficient, stable and continuous oxygen production. One obstacle is that the near-absence of buoyancy in microgravity results in hindered gas bubble desorption at the electrode-electrolyte interface, causing lower efficiencies for electrolyser systems when operating in space.1,2 The significantly reduced buoyancy force also has severe complications for phase separation, which is a crucial process for a variety of space technologies also including heat transfer, fuel production and removal of carbon dioxide from cabin air. Multiple approaches have been studied in the past to induce phase separation such as creating centrifugal force fields. These approaches lack however efficiency, stability and robustness.3,4 In our recent work, we demonstrate the use of magnetic polarisation to artificially induce buoyancy in the electrolytic oxygen evolution half-cell reaction and thus significantly increasing the overall half-cell efficiency. This was carried out in a series of experiments at the Bremen Drop Tower, Center of Space Technology and Microgravity (ZARM, Germany), where short-term microgravity conditions of 9.2 s were achieved.5,6. Chronoamperometric and cyclic voltammetry measurements on high-activity RuOx electrocatalyst structures on a Ti substrate were undertaken with and without a magnet in close proximity to the electrode to closely monitor the electrochemical performance in a three-electrode potentiostatic arrangement and to demonstrate the magnetic effect on gas bubble desorption during free fall. It was observed that current densities for the electrodes at a potential of +1.49 V vs RHE were significantly higher in the presence of a magnet. We conclude that magnetic phase separation can be utilised in electrolytic systems in reduced gravitational environments to efficiently detach oxygen bubbles from the electrode surface and operate the devices at higher efficiencies, providing a key advancement for future oxygen production in space missions.2,3,5 References Cheng, W.-H.; Richter, M. H.; May, M. M.; Ohlmann, J.; Lackner, D.; Dimroth, F.; Hannappel, T.; Atwater, H. A.; Lewerenz, H.-J. (2018). Monolithic Photoelectrochemical Device for Direct Water Splitting with 19% Efficiency. ACS Energy Lett., 3, 1795−1800.Saravanabavan, S.; Coulthard, C. T.; Kaur, M.; Brinkert, K. (2022). Catalysis in Space Environments. doi.org/10.1002/9783527830909.ch7 In: Hessel V., Stoudemire J., H. Miyamoto & I. D. Fisk (Eds.). In Space Manufacturing and Resources.Wiley-VCH. ISBN: 978-3-527-83091-6Romero-Calvo, Á.; Akay, Ö.; Schaub, H.; Brinkert, K. (2022). Magnetic phase separation in microgravity. npj Microgravity 8 (32). doi.org/10.1038/s41526-022-00212-9.Harvey, A.; Ramshaw, C.; Reay, D. A. Process Intensification: Engineering for Efficiency. Sustainability and Flexibility. 2nd edition. Butterworth- Heinemann; 201Brinkert, K.; Richter, M. H.; Akay, Ö.; Liedtke, J.; Giersig, M.; Fountaine, K. T.; Lewerenz, H. J. (2018). Efficient solar hydrogen production in microgravity environment. Commun. 9(2527). doi: 10.1038/s41467-018-04844-yhttps://www.zarm.uni-bremen.de/fileadmin/user_upload/drop_tower/Users_Manual_0412.pdf

Electrochemical Characteristics of Novel Fluorinated Ether Solvent for Lithium-Sulfur Batteries

Introduction In recent years, the development of electric airplanes, large drones, and other equipment has created a need for batteries with high energy density and high power density. Lithium-sulfur batteries have been investigated as such batteries. Electrolyte solutions applying carbonate solvents and ether solvents have been developed as electrolyte for lithium-sulfur batteries1. An electrolyte with ether-based solvents is lighter than that with carbonate-based solvents, so the former is expected to be an electrolyte for lithium sulfur batteries with high energy density. However, lithium-sulfur batteries based on ether solvents have difficulty in reversible charge-discharge reactions due to the dissolution of lithium polysulfide (Li2S x ) that occurs during the charge-discharge process2. In this study, we investigate the electrochemical characteristics of electrolytes to apply a new fluorinated ether (C14) which is resistant to elution of Li2S x . Experimental Sulfur-carbon composite (S-C) was prepared by compositing activated carbon (C-novel, Toyo Tanso) and sulfur in a ratio of 35:65 by weight using a thermal impregnation method. S-C was used as the active material and mixed with acetylene black (AB, DENKA), carboxymethyl cellulose (CMC), and styrene-butadiene rubber (SBR) to prepare a slurry. The cathode was obtained by coating the obtained slurry on an aluminum foil by a doctor blade method. An electrochemical cell was assembled with the obtained cathode as the working electrode, Li foil as the counter electrode, and LiTFSI dissolved in a mixture of dioxolane (DOL), dimethoxyethane (DME), and C14 at a concentration of 1 mol L-1 as the electrolyte. In order to clarify the electrochemical characteristics of the lithium sulfur battery with these electrolytes, constant current charge-discharge tests were conducted using the electrochemical cell described above. To clarify the coordination state of the solvent to lithium ions and lithium polysulfide in the electrolyte, IR spectra were measured for these electrolytes. Results and Discussion In the IR spectra for the solutions of Li2S x dissolved in DME, the intensity of the peak attributed to the asymmetric stretching of the C-O-C bond, which can be seen at around 1090 cm-1, increases with increasing concentration of Li2S x . The change in peak intensity appears to be due to the coordination of the structure of the diether in DME to the Li+ of Li2S x . On the other hand, in the IR spectra of Li2S x immersed in C14, the intensity of the corresponding peak was found to be similar to that of C14 only, regardless of the concentration of Li2S x . The results indicate that C14 is hard to coordinate to Li2Sx. This may be due to the fact that the functional group with fluorine in the structure of C14 is an electron-withdrawing group, which delocalizes the electrons located around O in the diether and weakens the coordinative force to Li2Sx. As a result of the constant-current charge-discharge test, it was confirmed that the voltage stagnated at about 2.3 V in the charge curves of the cell to which 1M LiTFSI / DOL : DME = 1 : 1 by vol.% was applied. The stagnation of the voltage is considered to be due to the shuttle reaction caused by the coordination of DME to lithium polysulfide and its dissolution into the electrolyte during the charge-discharge process. On the other hand, in the charge-discharge curves of the cell with 1M LiTFSI / C14, the stagnation of voltage that was observed in the cell with 1M LiTFSI / DME could not be confirmed, and it was turned out that the irreversible capacity was small. This should be due to the inability of C14 to coordinate with Li2S x . Acknowledgement A part of this research was conducted under a subcontract (JPNP15005) from the New Energy and Industrial Technology Development Organization (NEDO), a national research and development corporation. Reference 1) L. Gordin et al, ACS Appl. Mater. Interfaces, 6 (2014) 8006−80102) B. Zhang et al, ACS Energy Lett., 6 (2021) 537−546

Towards a Fully-Quantitative Picture of SEI Chemical Composition and Its Native Li+ Exchange in Liquid Electrolytes

Energy density requirements for next-generation batteries make the lithium (Li) metal anode a key candidate to replace graphite in lithium-ion batteries due to Li’s improved capacity (3,860 mAh/g vs. 372 mAh/g). However, Li anodes display lower Coulombic efficiency (CE, <99.9%) than graphite (>99.95%),1 resulting in faster loss of reversible Li over cycling. This shortfall derives from parasitic Li-electrolyte reactions that lead to accumulation of inactive Li0 and electrolyte-derived byproducts, which result in the formation of a native solid electrolyte interphase (SEI) on Li. In addition to contributing to capacity loss, the SEI also has the important role of regulating Li+ exchange between Li and the electrolyte, which may affect Li plating morphology and reversibility.2 Despite significant advances, the framework on which the understanding of SEI composition and function was built has largely been qualitative, often due to experimental limitations and/or lack of self-consistent techniques.To bridge this gap, my thesis work focuses on advancing experimental techniques and methodologies to precisely quantify the chemical composition and rates of Li+ exchange in native SEIs. Using a combination of cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS), self-consistent rates of Li+ exchange are reported across a wide range of electrolytes.3 Notably, we found that native SEIs formed in high CE electrolytes displayed consistently higher rates of Li+exchange. The improved transport in high-CE electrolytes was found to emerge after an SEI formation cycle, and amplified over cycling, indicating that fast Li+ exchange is beneficial to Li reversibility.In order to identify which SEI phases grant high-CE electrolytes their beneficial functional properties, we also developed and expanded upon a series of titration experiments based on GC, ICP-AES and NMR that can track an extended array of key SEI phases: semicarbonates (ROCO2Li), lithium carbide (Li2C2), olefins (RLi), LiF, P-containing phases, and total Li loss.4 In the 1 M LiPF6 EC/DEC electrolyte, we demonstrate chemical resolution up to 71% of Li loss and 33% of SEI loss. Among the quantifiable SEI phases, ROCO2Li was consistently the major phase, but its proportions were invariant with CE. Instead, Li2C2, a minor phase, exhibited clear inverse correlation with CE. We also demonstrate further quantitative chemical resolution can be achieved with online GC, which can differentiate between the different types of semicarbonate (i.e., which “R” in ROCO2Li) and alkoxide phases that form on Li.5 Altogether, these results add further nuance to the current understanding of SEI composition and their function, which we hope will allow more quantitative electrolyte design. Hobold, G. M.; Lopez, J.; Guo, R.; Minafra, N.; Banerjee, A.; Shirley Meng, Y.; Shao-Horn, Y.; Gallant, B. M., Moving Beyond 99.9% Coulombic Efficiency for Lithium Anodes in Liquid Electrolytes. Nat. Energy 2021, 6 (10), 951-960. Zheng, J.; Kim, M. S.; Tu, Z.; Choudhury, S.; Tang, T.; Archer, L. A., Regulating Electrodeposition Morphology of Lithium: Towards Commercially Relevant Secondary Li Metal Batteries. Chem. Soc. Rev. 2020, 49 (9), 2701-2750. Hobold, G. M.; Kim, K.-H.; Gallant, B. M., Beneficial Vs. Inhibiting Passivation by the Native Lithium Solid Electrolyte Interphase Revealed by Electrochemical Li+ Exchange. 2022. Hobold, G. M.; Gallant, B. M., Quantifying Capacity Loss Mechanisms of Li Metal Anodes Beyond Inactive Li0. ACS Energy Lett. 2022, 7 (10), 3458-3466. Hobold, G. M.; Khurram, A.; Gallant, B. M., Operando Gas Monitoring of Solid Electrolyte Interphase Reactions on Lithium. Chem. Mater. 2020, 32 (6), 2341-2352.

Probing the Stability of Lithium Carbonate in the Lithium-Metal Solid Electrolyte Interphase

The chemical composition and structure of the solid electrolyte interphase (SEI) are two of the key factors that determine the reversibility of lithium-metal (Li) anodes for next-generation batteries. As a result, much of the research aimed at enabling practical Li-metal batteries emphasizes tuning SEI composition, either via electrolyte formulation1–5 or synthesis of artificial SEIs.6–8 Ideally, the lithium SEI should minimize parasitic side reactions by effectively passivating Li while also promoting facile conduction of lithium ions (Li+). To do this, SEI materials must have high (electro)chemical stability, be ionically conductive, and be sufficiently mechanically robust to accommodate substantial volume changes. However, studying these properties in bulk-scale materials often yields values that diverge by orders of magnitude from those observed in SEIs. For example, typical SEI ionic conductivities lie in the range of 10-7-10-9 S cm-1, yet bulk ionic conductivity measurements of relevant materials such as lithium carbonate, lithium fluoride, and lithium oxide ranges from 10-18 and 10-10 S cm-1.9 Our group has developed a technique to directly study these materials at realistic length scales by synthesizing model interphases through the reaction of gases with Li.10,11 Our previous work on Li2O and LiF revealed that Li2O is a better Li+ conductor than LiF (~1 x 10-9 S cm-1 vs ~5.2 x 10-10 S cm-1),11 and that these species’ chemical stability varies substantially in different electrolytes.12 One of the remaining key SEI materials is lithium carbonate, which has been proposed to act as a metastable phase in the outer portion of the SEI.13 In this work, we have developed a technique to synthesize Li2CO3 films via sequential reaction of oxygen and carbon dioxide with clean lithium surfaces. Using scanning electron microscopy and air-exposure tests, we can confirm that these films are conformal and generally pinhole-free. Titration gas chromatography (TGC)14 was used to quantify relative proportions of lithium carbonate, metallic lithium, and lithium carbide, and X-ray photoelectron spectroscopy (XPS) offers insights into how composition changes across the depth of the film. These films were then used as a platform to further investigate the reactivity of Li2CO3 with different electrolytes, comparing carbonates versus ethers and varying the lithium salt used. Electrochemical impedance spectroscopy (EIS) offers insights into the evolution of transport properties at these interphases, while electrolyte soak tests coupled with gas chromatography of gas-phase products and TGC of solid-phase products can track their chemical evolution. Taken together, this work illuminates how lithium carbonate may evolve during battery cycling, offering perspective that can help guide future design of Li-metal SEIs.References Liu, Y. et al. Solubility-mediated sustained release enabling nitrate additive in carbonate electrolytes for stable lithium metal anode. Nat. Commun. 1–10 (2018).Suo, L. et al. Fluorine-donating electrolytes enable highly reversible 5-V-class Li metal batteries. Proc. Natl. Acad. Sci. 115, 1156–1161 (2018).Chae, O. B., Adiraju, V. A. K. & Lucht, B. L. Lithium Cyano Tris(2,2,2-trifluoroethyl) Borate as a Multifunctional Electrolyte Additive for High-Performance Lithium Metal Batteries. ACS Energy Lett. 6, 3851–3857 (2021).Li, Y. et al. Correlating Structure and Function of Battery Interphases at Atomic Resolution Using Cryoelectron Microscopy. Joule 2, 2167–2177 (2018).Zhao, Q. et al. Upgrading Carbonate Electrolytes for Ultra‐stable Practical Lithium Metal Batteries. Angew. Chemie Int. Ed. 61, e2021162 (2021).Zhao, J. et al. Surface Fluorination of Reactive Battery Anode Materials for Enhanced Stability. J. Am. Chem. Soc. 139, 11550–11558 (2017).Li, Y. et al. Robust Pinhole-free Li3N solid electrolyte grown from molten lithium. ACS Cent. Sci. 4, 97–104 (2018).Kozen, A. C. et al. Next-Generation Lithium Metal Anode Engineering via Atomic Layer Deposition. ACS Nano 9, 5884–5892 (2015).Lorger, S., Narita, K., Usiskin, R. & Maier Films of Li, J. Enhanced ion transport in Li2O and Li2S films. Chem. Commun 57, 6503–6506 (2021).He, M., Guo, R., Hobold, G. M., Gao, H. & Gallant, B. M. The intrinsic behavior of lithium fluoride in solid electrolyte interphases on lithium. PNAS 117, 73–79 (2020).Guo, R. & Gallant, B. M. Li 2 O Solid Electrolyte Interphase: Probing Transport Properties at the Chemical Potential of Lithium. Chem. Mater 32, 5525–5533 (2020).Guo, R., Wang, D., Zuin, L. & Gallant, B. M. Reactivity and Evolution of Ionic Phases in the Lithium Solid−Electrolyte Interphase. ACS Energy Lett. 877–885 (2021) doi:10.1021/acsenergylett.1c00117.Han, B. et al. Poor Stability of Li2CO3 in the Solid Electrolyte Interphase of a Lithium-Metal Anode Revealed by Cryo-Electron Microscopy. Adv. Mater. 33, 2100404 (2021).Hobold, G. M. & Gallant, B. M. Quantifying Capacity Loss Mechanisms of Li Metal Anodes beyond Inactive Li0. ACS Energy Lett. 4, 3458–3466 (2022).

(Best Student Presentation) Is Solid-Electrolyte Interphase Formation Affected by Electrode Conductivity?

Accurate analysis of the mechanism of interphase formation and its composition is imperative for the development of stable and efficient lithium/sodium-ion batteries. One of the most practically scalable ways to optimize interphase chemistry and morphology for reversible charge transport is electrolyte engineering and the application of formation protocol with specific current/voltage conditions. In this sense, the analysis of structure and dynamics within the electrode/electrolyte interface, i.e., the so-called electric-double layer, is essential to predicting the possible chemistry and mechanism of interphase formation.The latest was recently advanced by understanding the effect of electrolyte chemistry, e.g., the chemical structure of solvent and salt, their ratio, the presence of additives etc.1–4 Although, the role of electrode material is often neglected which creates an impression that both metallic and semiconductive electrodes form an identical electric-double layer within the same electrolyte, therefore, the mechanism of interphase formation should be very similar regardless of the chemical nature of the electrode.Here, we used examples of sodium-salt-containing ionic liquids and carbonate electrolytes to demonstrate that structural changes at the electrified interface are greatly affected by the dielectric nature of electrode material. The key observation is attributed to the different abilities of electrified electrodes to form van der Waals interactions with the electrolyte species. This affects the concentration of metal-anion complexes in relation to organic solvent near the electrode, therefore, different interphase chemistry will be formed (inorganic-rich vs. organic-rich), and different formation protocols must be used. For example, Fig. 1 shows the summary of this phenomenon for ionic liquid electrolytes with 50 mol% sodium bis(fluorosulfonyl)imide. Besides, metallic and semiconductive electrodes demonstrated different affinity toward polar organic solvent, i.e., ethylene carbonate, in 1.0 M NaPF6 in EC:DMC (1:1 by volume) electrolyte. This presentation will discuss the details of these fundings and introduce future applications. Fig. 1 | Schematic relationships between solid-electrolyte interphase (SEI) composition, applied current of preconditioning cycling, and dielectric nature of anode material.References Zheng, X. et al. Toward High Temperature Sodium Metal Batteries via Regulating the Electrolyte/Electrode Interfacial Chemistries. ACS Energy Lett. 7, 2032–2042 (2022).Rakov, D. A. et al. Engineering high-energy-density sodium battery anodes for improved cycling with superconcentrated ionic-liquid electrolytes. Nat. Mater. 19, 1096–1101 (2020).Rakov, D. A. et al. Polar Organic Cations at Electrified Metal with Superconcentrated Ionic Liquid Electrolyte and Implications for Sodium Metal Batteries. ACS Mater. Lett. 4, 1984–1990 (2022).Rakov, D. et al. Stable and Efficient Lithium Metal Anode Cycling through Understanding the Effects of Electrolyte Composition and Electrode Preconditioning. Chem. Mater. (2021). doi:10.1021/acs.chemmater.1c02981 Figure 1

Species Crossover in Electrochemical CO2 Reduction

Catalyst studies have improved the overall CO2R (electrochemical CO2 reduction) faraday efficiency (FE)1, however, the experimental FE can be deteriorated by product crossover through the membrane in a practical electrochemical CO2R cell. The CO2R product molecules generated at the cathode are subject to oxidation at the anode if they permeate through the membrane, thus decreasing the practical CO2R product collection. The product loss at the anode also poses a challenge for quantification and study of the crossover behavior2–4. In this work, we will present experimental designs that effectively overcome the oxidation at the anode to reveal the CO2R product crossover.The CO2R product crossover can be driven by electromigration and the concentration gradient across the membrane. Although the electromigration plays a significant role based on the current density of CO2R operation, the later can be varied by membrane design parameters. The membrane thickness and non-ionic reinforcement layers can effectively change the permeability of various CO2R product species. The CO2R product crossover measurements of commercially available anion exchange membranes will be presented.From a fundamental perspective, CO2R product crossover is a reflection of membrane selectivity. We also extend the component study to the cell level where parameters like electrolyte concentration/conductivity and electrolyte/CO2 flow rate also affect the crossover. The species other than products in CO2R can have impact on both catalyst performance and crossover. We will discuss the crossover behavior in our standard CO2R setup5,6. Overall, we aim to address the CO2R product crossover by bridging the fundamental study of a component and CO2R integration efforts at NREL. Ge, L. et al. Electrochemical CO2 reduction in membrane-electrode assemblies. Chem 8, 663–692 (2022).McCallum, C. et al. Reducing the crossover of carbonate and liquid products during carbon dioxide electroreduction. Cell Rep. Phys. Sci. 2, 100522 (2021).Wang, N. et al. Suppressing the liquid product crossover in electrochemical CO2 reduction. SmartMat 2, 12–16 (2021).Zhang, J., Luo, W. & Züttel, A. Crossover of liquid products from electrochemical CO2 reduction through gas diffusion electrode and anion exchange membrane. J. Catal. 385, 140–145 (2020).Chen, Y. et al. A Robust, Scalable Platform for the Electrochemical Conversion of CO2 to Formate: Identifying Pathways to Higher Energy Efficiencies. ACS Energy Lett. 5, 1825–1833 (2020).Chen, Y. et al. The effect of catholyte and catalyst layer binders on CO2 electroreduction selectivity. Chem Catal. 2, 400–421 (2022).

Preferential Coordination As a Means to Investigate Ca2+ Speciation and SEI Formation

Given concerns about the low earth abundance of Li in Li-ion batteries, there is growing interest in developing a beyond-Li materials basis for rechargeable batteries. Divalent batteries based on calcium (Ca) have received attention due to their ~2000-fold higher concentration in the earth’s crust along with attractive theoretical metrics if Ca is used as the metallic anode. When most common battery electrolytes come into contact with Ca, however, a passivating solid electrolyte interphase (SEI) forms that prevents Ca2+ transport.1 At present, only a small number of nonaqueous electrolytes have been identified that form sufficiently Ca2+-conductive SEIs for Ca electrodeposition, limiting the design space for Ca battery development. Thus, learning how to tailor Ca SEI formation is of central importance to identify handles for next-generation battery design. Several methods of modifying SEI to improve Ca2+ transport have been reported, including synthesizing an ex situ artificial layer,2 or the introduction of boron-containing electrolyte additives that form beneficial SEI compounds.3 Ca electrolyte modification faces a unique challenge, however, as the large size and divalent nature of Ca2+ leads to large coordination environments (up to 7 solvating molecules) in solution.4 Recent studies have begun to identify that co-reduction of these coordinating molecules has a significant impact on Ca electrochemistry. For example, strong coordination between Ca2+ and the anion TFSI- has been demonstrated to deactivate Ca plating behavior via TFSI- decomposition.5,6 However, competition between coordinating molecules can be exploited to favor specific Ca2+ speciation (i.e. BH4 - displaces bidentate TFSI---Ca2+ in favor of BH4 ---Ca2+ interactions) and unlock Ca plating behavior.6 Further mechanistic understanding is needed to identify the specific connections between Ca2+ coordination, SEI formation, and anode performance (beyond just a binary toggling of plating behavior). To address this, we have systematically introduced chelating glyme-based solvents into a baseline electrolyte, investigating the subsequent changes in SEI composition and electrochemical behavior.This study investigates the preferential coordination of Ca2+ by glymes in the baseline electrolyte 1 M Ca(BH4)2 in tetrahydrofuran (THF). THF is systematically replaced by 1,2-dimethoxyethane (G1) or bis(2-methoxyethyl) ether (G2) over a range of Gx/Ca2+ molar ratios. Microcalorimetry measurements demonstrate that the introduction of both G1 and G2 to the electrolyte is enthalpically favorable, as each glyme displaces THF from the Ca2+ coordination sphere and modulates Ca2+--BH4 - speciation, as indicated by NMR and Raman spectroscopy. Addition of a small amount of each glyme (1:1 Gx/Ca2+) increases electrolyte ionic conductivity by nearly half; however, glyme addition systematically increases the overpotentials of both Ca plating and stripping while decreasing Coulombic efficiency. The presence of glymes increases the amount of carbon present in both chemically- and electrochemically-formed SEI as indicated through XPS. We further find increased evidence of fragmentation of strongly Ca2+-coordinating molecules (G2, BH4 -) within the SEI formed during Ca deposition as compared to formed chemically. Calcium-based olefins as well as ionic phases (CaCO3, CaC2) are detected in electrochemically-formed SEI through titration gas chromatography. This work reveals factors that modulate both Ca2+ coordination and subsequent SEI formation, highlighting preferential coordination as a novel approach for Ca-based electrolyte design.1 Aurbach, D., Skaletsky, R. & Gofer, Y. The Electrochemical Behavior of Calcium Electrodes in a Few Organic Electrolytes. Journal of The Electrochemical Society 138, 3536-3545 (1991).2 Hou, Z., Zhou, R., Min, Z., Lu, Z. & Zhang, B. Realizing Wide-Temperature Reversible Ca Metal Anodes through a Ca2+-Conducting Artificial Layer. ACS Energy Letters, 274-279 (2022).3 Bodin, C. et al. Boron-Based Functional Additives Enable Solid Electrolyte Interphase Engineering in Calcium Metal Battery. Batteries & Supercaps n/a, e202200433 (2022).4 Tchitchekova, D. S. et al. On the Reliability of Half-Cell Tests for Monovalent (Li+, Na+) and Divalent (Mg2+, Ca2+) Cation Based Batteries. Journal of The Electrochemical Society 164, A1384-A1392 (2017).5 Hahn, N. T. et al. Influence of Ether Solvent and Anion Coordination on Electrochemical Behavior in Calcium Battery Electrolytes. ACS Applied Energy Materials 3, 8437-8447 (2020).6 Melemed, A. M., Skiba, D. A. & Gallant, B. M. Toggling Calcium Plating Activity and Reversibility through Modulation of Ca2+ Speciation in Borohydride-Based Electrolytes. The Journal of Physical Chemistry C 126, 892-902 (2022).

(Invited) Electrocatalytic Conversion of CO2 to Syngas with Controlled CO/H2 Ratios

One of the main research challenges for electrocatalysis that produces carbon-containing products from CO2 is avoiding the competing hydrogen evolution reaction. Instead of totally eliminating hydrogen, our approach makes use of the readily available protons in aqueous electrolyte to co-produce CO and H2, making synthesis gas (syngas) with a tunable CO:H2 ratio. The resulting syngas can then be used as feedstock for existing thermocatalytic processes, such as Fischer–Tropsch and methanol synthesis reactions [1]. We will present our results in identifying palladium hydride (PdH), formed under electrocatalytic reaction conditions, as an effective electrocatalyst that enables the syngas production [2]. We will also report our efforts in reducing the loading of Pd by alloying Pd with inexpensive secondary metals, supporting Pd on transition metal carbides and nitrides, and utilizing single atom Pd catalysts. For each type of the catalysts, we monitor the phase transition from Pd to PdH under reaction conditions with in-situ synchrotron-based X-ray absorption and X-ray diffraction techniques. We also identify descriptors for syngas production on PdH, bimetallic PdH, and supported PdH catalysts by performing DFT calculations of the effect of PdH formation on the binding strength of reaction intermediates. The research methodology established here should be useful not only for continued optimization of Pd-based syngas-producing electrocatalysts, but also for enhancing activity while reducing the loading of precious metals for other electrocatalytic applications. Furthermore, we will discuss our recent results in utilizing a tandem scheme of electrocatalytic-thermocatalytic processes to convert CO2 to C3 oxygenates [3].[1] B.M. Tackett, E. Gomez and J.G. Chen, “Net reduction of CO2 via its thermocatalytic and electrocatalytic transformation reactions in standard and hybrid processes”, Nature Catalysis, 2 (2019) 381.[2] B.M. Tackett, J.H. Lee and J.G. Chen, “Electrochemical Conversion of CO2 to Syngas with Palladium-Based Electrocatalysts”, Accounts of Chemical Research, 53 (2020) 1535.[3] A.N. Biswas, Z. Xie, R. Xia, S. Overa, F. Jiao and J.G. Chen, “Tandem Electrocatalytic-Thermocatalytic Reaction Scheme for CO2 Conversion to C3 Oxygenates”, ACS Energy Letters, 7 (2022) 2904

High-Performance K Metal Batteries Enabled by Regulating an Electrolyte Solvation Structure

Batteries using a potassium metal (K-metal) anode are attention to a new type of low-cost and high-energy storage devices. However, the thermodynamic instability of the K-metal anode in organic electrolyte solutions causes uncontrolled growth of dendrites and parasitic reactions, which leads rapid capacity loss and low Coulombic efficiency.[1-4] In this presentation, I will introduce the advanced electrolyte using dual-salt for regulated solvation chemistry showing an improved the K-metal anode stability. Experimental and theoretical studies supported the details of solvation chemistry and results. Incorporating dual-salt into the electrolyte solution decreased the number of free solvent molecules surrounding the K+ leading to facile K+ desolvation as well as lowering the exchange current density improving the uniform K electrodeposition. Moreover, the modified electrolyte mitigates decomposition of the solvent molecules and leads to form enhanced mechanical rigidity of the SEI layer on the surface of the K–metal electrode with larger fraction of KF compound. Compared to previous studies, the K-metal anode using modified electrolyte shows long cycling stability at fast charge-discharge capability in symmetrical K | K cells. Even under high current density, the modified electrolyte ensures high areal capacity and an unprecedented lifespan with stable Coulombic efficiency for the K-metal full battery employing a sulfurized polyacrylonitrile cathode. M. Park, Y. Jeong, M. H. Alfaruqi, Y. Liu, X. Xu, S. Xiong, M.–G. Jung, H.–G. Jung, J. Kim, J.–Y. Hwang, Y.–K. Sun. Stable Solid Electrolyte Interphase for Long–Life Potassium Metal Batteries, ACS Energy Lett. 7 (2022) 401–409.Kim, W. Song, D.–Y. Son, L. K. One, Y. Qi. Lithium–Ion Batteries: Outlook on Present, Future, and Hybridized Technologies. J. Mater. Chem. A 7 (2019) 2942–2964.–H. Kim, G.–T. Park, B.–K. Son, G. W. Nam, J. Liu, L.–Y. Kuo, P. Kaghazchi, C. S. Yoon, Y.–K. Sun. Heuristic Solution for Achieving Long–Term Cycle Stability for Ni–Rich Layered Cathodes at Full Depth of Discharge, Nat. Energy 5 (2020) 860.–Y. Hwang, S.–T. Myung, Y.–K. Sun. Recent Progress in Rechargeable Potassim Batteries, Adv. Funct. Mater. 28 (2018) 1802938.

3D Printing of Batteries from Lunar and Martian Regolith

To maximize the sustainability of future space missions, the utilization of local resources available on the Moon or Mars, also known as in-situ resource utilization (ISRU), is crucial to develop infrastructures such as habitation modules, power generation, and energy storage facilities.1–3 This work presents a perspective aiming to introduce the future of batteries manufacturing on the lunar and martian environment from ISRU materials. Based on the composition of the lunar and martian soil,4–7 the choice of the battery technology and materials for the different battery components (electrodes, electrolyte, current collectors and packaging) are examined. The motivations for selecting additive manufacturing technologies as a unique approach to support human operations in space, on the surface of the Moon or Mars, and any other locations where cargo resupply is not as readily available, as well as the need for high resolution multi-material printing methods, are discussed. Additive manufacturing paves the way to three-dimensional rechargeable battery architectures with enhanced specific surface area, three-dimensional ion diffusion, and improved power performances, while also allowing the development of shape-conformable batteries to maximize the energy storage within the final application.8–15 The in-space additive manufacturing process of shape-conformable batteries using in-situ resources is in direct alignment with the NASA’s objectives to demonstrate in-space autonomous manufacturing and assembly of complete systems by 2030, and to enable Humans survival, explore deep space, and visit planetary surfaces by 2040.16 Such initiatives also contribute to reducing power-related payload weight and volume in future missions, thus reducing the risk for long term Moon or even Mars missions where rapid resupply will be logistically infeasible. In this context, this presentation will provide a perspective of what is required to 3D print batteries on lunar and martian surfaces,17 an overview of our ongoing project dedicated to AM of sodium-ion batteries from resources available on the Moon and Mars and our recent work on 3D printing of TiO2 negative electrode material by means of the vat photopolymerization process.18 (1) Anand, M. et al. A Brief Review of Chemical and Mineralogical Resources on the Moon and Likely Initial in Situ Resource Utilization (ISRU) Applications. Planet. Space Sci. 2012, 74 (1), 42–48.(2) Edmunson. Building a Sustainable Human Presence on the Moon and Mars. New Horizons Summit.(3) McMillon-Brown, L. et al. What Would It Take to Manufacture Perovskite Solar Cells in Space? ACS Energy Lett. 2022, 7 (3), 1040–1042.(4) Heiken, G. et al. Lunar Sourcebook: A User’s Guide to the Moon; CUP Archive, 1991.(5) Dreibus, G. et al. Lithium and Halogens in Lunar Samples. Philos. Trans. R. Soc. Lond. A 1977, 285 (1327), 49–54.(6) Taylor, G. J. The Bulk Composition of Mars. Geochem. Explor. Environ. Analy. 2013, 73 (4), 401–420.(7) Yoshizaki, T. et al. The Composition of Mars. Geochim. Cosmochim. Acta 2020, 273, 137–162.(8) Maurel, A. et al. Highly Loaded Graphite-Polylactic Acid Composite-Based Filaments for Lithium-Ion Battery Three-Dimensional Printing. Chem. Mater. 2018, 30 (21), 7484–7493.(9) Maurel, A. et al. Considering Lithium-Ion Battery 3D-Printing via Thermoplastic Material Extrusion and Polymer Powder Bed Fusion. Additive Manufacturing 2020, 101651.(10) Martinez, A. C. et al. Additive Manufacturing of LiNi1/3Mn1/3Co1/3O2 Battery Electrode Material via Vat Photopolymerization Precursor Approach. Sci. Rep. 2022, 12 (1), 1–13.(11) Maurel, A. et al. Overview on Lithium-Ion Battery 3D-Printing By Means of Material Extrusion. ECS Trans. 2020, 98 (13), 3–21.(12) Maurel, A. et al. Toward High Resolution 3D Printing of Shape-Conformable Batteries via Vat Photopolymerization: Review and Perspective. IEEE Access 2021, 9, 140654–140666.(13) Maurel, A. et al. Ag-Coated Cu/Polylactic Acid Composite Filament for Lithium and Sodium-Ion Battery Current Collector Three-Dimensional Printing via Thermoplastic Material Extrusion. Frontiers in Energy Research 2021, 9 (70). https://doi.org/10.3389/fenrg.2021.651041.(14) Ragones, H. et al. Towards Smart Free Form-Factor 3D Printable Batteries. Sustainable Energy & Fuels 2018, 2 (7), 1542–1549.(15) Egorov, V. et al. Evolution of 3D Printing Methods and Materials for Electrochemical Energy Storage. Adv. Mater. 2020, 32 (29). https://doi.org/10.1002/adma.202000556.(16) Murphy, P. STMD’s New Strategic Framework Update, 2017. https://www.nasa.gov/sites/default/files/atoms/files/336429-508-to5_nac_dec_2017_strategicplanningintegration_tagged.pdf.(17) Maurel, A. et al. What Would Battery Manufacturing on the Moon and Mars Look Like? (submitted).(18) Maurel, A. et al. 3D Printed TiO2 Negative Electrodes for Sodium-Ion and Lithium-Ion Batteries Using Vat Photopolymerization (submitted).

Photoelectrochemical Devices for Oxygen and Fuel Production on Moon and Mars

Human space exploration and the realisation of a green energy economy on Earth are confronted with the same challenge: both require efficient, stable and reliable renewable energy systems.1 Currently existing solutions such as the water electrolyzer in operation on the International Space Station (ISS) for oxygen and hydrogen production are not feasible in future lunar and Martian habitats as they are too bulky and heavy to transport and they lack the required reliability and efficiency2. Photoelectrochemical (PEC) devices not only meet the weight and volume constraints imposed onto devices for space applications by utilising a monolithic design for light absorption, charge separation and catalysis,3 they can also directly be coupled to solar concentrators in order to harvest the abundant solar energy available in space. Despite the advantages, PEC devices are nearly exclusively researched and developed for terrestrial applications and only a very few examples explore the possibility of utilizing the integrated semiconductor-electrocatalyst systems for space applications.4 Here, we present an unprecedented theoretical analysis of the applicability of PEC devices for lunar solar water-splitting and Martian CO2 reduction. These target reactions are in line with roadmaps of international space organisations aiming at a habitat establishment on the lunar South Pole, where water ice is assumed to be present in the Shackleton Crater. Furthermore, the atmosphere on Mars is composed of about 96% gaseous CO2, motivating our choice to investigate Martian CO2 to CO and CH4 conversion.5 Both reaction products could be used as propulsion additives or as precursors for the synthesis of hydrocarbon-based molecules in analogy to terrestrial applications. Firstly, we calculated a refined Martian solar irradiance spectrum and established the theoretical framework to describe PEC devices on Moon and Mars before calculating device limiting efficiencies and expected product rates for realistic devices at different solar irradiance scenarios. Our findings emphasise that PEC devices are indeed applicable on Moon and Mars, particularly when coupled to solar concentrators. In addition, it is evident that gas diffusion electrodes (GDEs), which mark a significant part of CO2 reduction devices investigated terrestrially, are surprisingly not necessarily viable in situations of limited solar irradiance such as present on Mars.References Ross B, Haussener S, Brinkert K. Photoelectrochemical devices for oxygen and fuel production on Moon and Mars. In review. Brinkert K, Mandin P. Fundamentals and future applications of electrochemical energy conversion in space. npj Microgravity 8, (2022).Cheng W-H, et al. Monolithic Photoelectrochemical Device for Direct Water Splitting with 19% Efficiency. ACS Energy Letters 3, 1795-1800 (2018). Brinkert K, et al. Efficient solar hydrogen generation in microgravity environment. Nature Communications 9, (2018). Yoshizaki T, McDonough WF. The composition of Mars. Geochimica et Cosmochimica Acta 273, 137-162 (2020).

High Areal-Capacity Aqueous Manganese-Based Batteries Enabled by Redox Mediators

Aqueous manganese batteries based on deposition-dissolution of Mn2+/MnO2 reactions have aroused great attention due to their intrinsic low cost, high potential, and high energy.1, 2 However, the incomplete dissolution and exfoliated dead MnO2 would inevitably lead to capacity loss and poor cyclability at high areal capacity application.3, 4 Herein, we apply a redox mediator strategy to dissolve the accumulated MnO2 via a spontaneous chemical reaction between redox mediators iodide and MnO2.5,6 During the discharge process, the iodide (I–) could react with the residual MnO2 and be oxidized to I3 – that could be further reduced back to I– on the electrode, continuing this process until fully dissolved the accumulated MnO2. We will discuss detailed reaction mechanisms verified by ex-situ UV-vis spectroscopy, scanning electron microscopy, and X-ray diffraction. The zinc-manganese (Zn-Mn) battery with iodide mediator showed improved cycling stability at 2.5 mAh cm–2 (400 vs. 100 cycles, static mode) and 15 mAh cm–2 (225 vs. 60 cycles, flow mode). Areal capacity is one of the most important parameters determining system energy for deposition-based batteries.7 The Zn-Mn flow cell could demonstrate a high areal capacity application at 50 mAh cm–2 for 50 cycles. We will discuss how to expand this strategy to other manganese-based batteries and broaden the horizon of aqueous batteries.AcknowledgmentThis work is supported by a grant from the Research Grant Council of the Hong Kong Special Administrative Region, China (project no. C1002-21G).Reference W. Chen, G. Li, A. Pei, Y. Li, L. Liao, H. Wang, J. Wan, Z. Liang, G. Chen, H. Zhang, J. Wang and Y. Cui, Nat. Energy, 2018, 3, 428-435. D. Chao, W. Zhou, C. Ye, Q. Zhang, Y. Chen, L. Gu, K. Davey and S.-Z. Qiao, Angew. Chem. Int. Ed. Engl., 2019, 58, 7823-7828. C. Liu, X. Chi, Q. Han and Y. Liu, Adv. Energy Mater., 2020, 10, 1903589. G. Liang, F. Mo, H. Li, Z. Tang, Z. Liu, D. Wang, Q. Yang, L. Ma and C. Zhi, Adv. Energy Mater., 2019, 9, 1901838. J. Lei, Y. Yao, Z. Wang and Y.-C. Lu, Energy Environ. Sci., 2021, 14, 4418-4426. J. Lei, Y. Yao, Y. Huang and Y.-C. Lu, ACS Energy Letters, 2022, DOI: 10.1021/acsenergylett.2c02524, 429-435. Y. Yao, J. Lei, Y. Shi, F. Ai and Y.-C. Lu, Nat. Energy, 2021, 6 (6), 582–588.

(Second Place Poster Award) Improving Oxygen Reduction Reaction ORR Fuel Cell Efficiency with Carbon Nano Onions

Hydrogen Fuel cell innovations are cutting-edge clean power solutions highly demanded nowadays. Since the oxygen reduction reaction (ORR) in fuel cells needs to be catalyzed heterogeneously, conductive substrates such as carbon materials are critical for the construction of electrocatalysts. Thus far, the research has been focused on commercially available carbon supports such as the well-known Vulcan, and the high-surface area Ketjenblack.[1] Thanks to the fast development of material science, other carbon supports such as graphite, graphene oxide, and carbon nanotubes have been also studied in a lesser extent, mainly due to their novelty and underdeveloped scale up syntheses.[2,3] This work focuses on utilizing a relatively new and, as of yet, largely unexplored carbon nanomaterial: carbon nano onions (CNOs).CNOs are spherical nanoparticles of about 5 nm diameter composed of concentrical multi-layered fullerenes, first discovered by Ugarte in 1992. CNOs exhibit outstanding properties such as low density, high thermal stability, and a graphitic multilayer morphology, which makes them excellent candidates for a wide variety of applications. Furthermore, the onion’s large surface area and high conductivity make them particularly interesting as catalyst support for electrochemical applications as they have already been demonstrated to be a superior Pt support alternative thanks to a higher cycling stability compared to carbon black, since their particle size and morphology suppress catalyst agglomeration and avoid its ripening.[4] However, despite their excellent long-term stability, the few available studies using CNOs were performed using the rotatory disc electrode (RDE) method, reaching only modest performance in the mA / cm2 range. Thus, our work aims to further extend upon this research by measuring the ORR performance with a gas diffusion electrode (GDE), to reproduce realistic fuel cell conditions.[5] The catalyst layer, obtained by growing Pt nanoparticles on CNOs, is characterized by electrochemical measurements such as ORR polarization curves, electrochemical active surface area (ECSA) by the CO-stripping method, and O2-mass transport. The utilization of GDE cells allows for higher current densities and a realistic catalyst mass transport compared to the RDE method, thus better representing an applied ORR fuel cell test.[6] [1] Electrochem. Solid-State Lett. 2005, 8, A320-A323[2] Carbon 2013, 58, 139-150[3] Energy Environ. Sci. 2010, 3, 1286-1293[4] ACS Appl. Mater. Interfaces 2017, 9, 28, 23302–23308[5] Angew. Chem. Int. Ed. 2021, 60, 8882-8888[6] ACS Energy Lett. 2022, 7, 2, 816–826 Figure 1

Conveniently Revealing Lithium-Ion Battery Reaction Kinetics Using Nonlinear Frequency Response Analysis

Nonlinear Frequency Response Analysis (NFRA) can be considered a nonlinear modification of galvanostatic EIS. Due to an increased AC excitation, higher harmonics are additionally present in the voltage response of the cell [1]. Here, a single particle model (SPM) [2] in the frequency domain is used for the simulation of the NFR of lithium-ion batteries (LiB). The time-dependent processes (double-layer charging, solid diffusion) are linear in currently available SPMs. Hence, they can be described algebraically as impedances in the frequency domain. From the nonlinear, time-independent equations (Butler-Volmer, Nernst), for the case of sinusoidal excitations, a system of algebraic equations for the fundamental and higher harmonics up to a freely selectable order N is derived. By combining these systems with the impedances, we obtain a still nonlinear SPM in the frequency domain, which can be solved in a purely algebraic way for the higher harmonics. The proposed model enables researchers to conveniently analyze the NFR of LiBs. This is especially beneficial for investigations of the reaction kinetics since charge transfer coefficients can be obtained directly by parameterizing the model with NFR measurements.The abilities of the model are shown with two exemplary cell setups. At first, a symmetric cell built from metallic lithium is analyzed. The measured impedance is used to parameterize a simple equivalent circuit model (ECM), including transport through the solid electrolyte interphase (SEI). The resulting exchange current densities are used within the frequency domain SPM, which represents a nonlinear version of the ECM. Subsequently, the charge transfer coefficients of the plating/stripping reaction can be obtained conveniently by comparing the NFR measurements with the SPM response. Since the sum of obtained charge transfer coefficients is smaller than one, they are interpreted in the sense of Marcus-Hush-Chidsey kinetics [3], which is possible within a certain range of overpotential. This leads to a distinct value for the solvent reorganization energy. The calculated value is in coincidence with literature values, which are relying on high scan rate CVs with ultramicroelectrodes [4].Secondly, a full pouch cell (NMC622/Graphite) was analyzed in a similar manner. Even though the SPM cannot capture microstructural effects of the porous electrode, a sufficient fit for the EIS measurement was found. After a subsequent parameterization of the charge transfer coefficients, the NFR measurement and simulation again agree well. The resulting values for intercalation reorganization energies at the graphite anode and NMC cathode are even lower than for the plating/stripping reaction. The reorganization energies could not be validated due to the lack of literature values. However, available values for LFP [5] and a value based on unpublished data for graphite [6], are also lower compared to the plating/stripping reaction.The proposed method is very promising since it can directly capture the complete nonlinear kinetics of an electrode. Due to the frequency dependence of LiBs, the separation of kinetic and diffusive effects remains as convenient as it is for EIS.If reorganization energies are considered as given, two persistent challenges in EIS analysis could be tackled: The separation of SEI resistance and charge transfer resistance since the latter is considered as nonlinear. In addition, the ionic transport resistance and charge transfer resistance could be separated for the same reason.In the future, microstructural effects should be integrated into the model. Vidaković-Koch, T.; Miličić, T.; Živković, L. A.; Chan, H. S.; Krewer, U.; Petkovska, M. Nonlinear Frequency Response Analysis: A Recent Review and Perspectives. Opin. Electrochem. 2021, 30, 100851. https://doi.org/10.1016/J.COELEC.2021.100851.Ning, G.; Popov, B. N. Cycle Life Modeling of Lithium-Ion Batteries. Electrochem. Soc. 2004, 151 (10), A1584. https://doi.org/10.1149/1.1787631/XML.Henstridge, M. C.; Laborda, E.; Rees, N. V.; Compton, R. G. Marcus–Hush–Chidsey Theory of Electron Transfer Applied to Voltammetry: A Review. Acta 2012, 84, 12–20. https://doi.org/10.1016/J.ELECTACTA.2011.10.026.Boyle, D. T.; Kong, X.; Pei, A.; Rudnicki, P. E.; Shi, F.; Huang, W.; Bao, Z.; Qin, J.; Cui, Y. Transient Voltammetry with Ultramicroelectrodes Reveals the Electron Transfer Kinetics of Lithium Metal Anodes. ACS Energy Lett. 2020, 5 (3), 701–709. https://doi.org/10.1021/acsenergylett.0c00031.Bai, P.; Bazant, M. Z. Charge Transfer Kinetics at the Solid-Solid Interface in Porous Electrodes. Commun. 2014, 5 (1), 1–7. https://doi.org/10.1038/ncomms4585.Gao, T.; Han, Y.; Fraggedakis, D.; Das, S.; Zhou, T.; Yeh, C. N.; Xu, S.; Chueh, W. C.; Li, J.; Bazant, M. Z. Interplay of Lithium Intercalation and Plating on a Single Graphite Particle. Joule 2021, 5 (2), 393–414. https://doi.org/10.1016/J.JOULE.2020.12.020. Figure 1

High Throughput Studies of Doped Li-La-Zr-O Garnet Solid Electrolytes

Lithium lanthanum zirconium oxide (LLZO) is a leading candidate for solid Li-batteries due to its high lithium-ion conductivity, stability in air and against Li metal, and compatibility with high-voltage cathodes.1,2 Despite significant research being done, our understanding of LLZO is limited by the relatively small number of compositions which have been studied; both in the larger Li-La-Zr-O system and in the doped cubic LLZO system, which can accommodate an extremely wide range of dopants.3To study this large number of compositions, we have applied a high-throughput methodology for synthesizing, characterizing, and testing sets of 64 LLZO electrolytes at the mg-scale. We employ a citrate sol-gel synthesis method whereby reagent solutions are dispensed across a well-plate to give a composition gradient. After drying and calcining the gels, the resulting powders are pelleted and then sintered at the desired temperature. High-throughput characterization techniques utilized include powder X-ray diffraction, impedance spectroscopy, DC polarization, and electrochemical stability window testing.Using our methodology, we have recently studied over 700 samples to produce a full phase stability diagram for the Li-La-Zr-O pseudoternary system.4 We found there is significant solubility of Li in the La2Zr2O7 pyrochlore structure, and that both cubic and tetragonal undoped LLZO appearing throughout the system have similarly poor bulk conductivities. This previous study again emphasizes the key role dopants play in LLZO. Herein, our methodology is applied to a comprehensive doping study where 60 different dopants are evaluated under identical synthesis conditions to allow for a thorough understanding of dopant effects on structure, ionic conductivity, electronic conductivity, and electrochemical stability window. Our samples achieve high conductivities over 1 mS/cm and relative densities above 90% with our combinatorial synthesis. Dopant content is optimized for each promising dopant to compare best-case results and correlate performance with structural properties like lattice parameters and density. Since comparing dopants in the literature is often difficult due to varying synthesis methods, this systematic work is essential in rational design of these electrolytes.1.Q. Liu, et al., J. Power Sources 2018, 389, 120-134.2.T. Thompson, et al., ACS Energy Letters 2017, 2, 462-468.3.F. Zheng, et al., J. Power Sources 2018, 389, 198-213.4.E. Anderson et al., DOI:10.1016/j.ssi.2022.116087.

Addressing the Stability Challenges of Gas Diffusion Electrodes in the Presence of ILs-Based Solutions for the Continuous Electrochemical Reduction of CO2

Nowadays, it has become clear that the ever-increasing concentration of carbon dioxide (CO2) in the atmosphere is a threat to global security1. Therefore, the adverse climate events remind us that a transition towards a carbon neutral economy is more necessary than ever. Several approaches have been proposed to convert CO2 to valuable products and, among these, the electrochemical reduction of CO2 (ECR-CO2) represents one of the most promising alternatives. Herein, the ECR-CO2 has been carried out for the first-time employing silver based-gas diffusion electrodes (GDEs) within a continuous flow cell and in the presence of ionic liquids (ILs)-based solutions, which have been known to boost CO2-derived products2. As reported in the literature, the instability of GDEs is initiated by the high overpotentials needed during the CO2 reduction reactions and usually culminates in flooding3. This eventually has a negative impact on the product selectivity as well as limits the perspectives of scalability. In particular, in this work, different stability issues have been faced and visualized, for example, in the blackening of typical carbon-based gas diffusion layers (GDLs) and in the degradation/colour changes of ILs-electrolyte. Interestingly, by switching to non-carbon based GDLs it has been possible to reach and maintain a steady-state production of carbon monoxide (CO) both at -10 mA cm-2 and at -20 mA cm-2 for at least 40 minutes, with a H2/CO ratio slightly above 2 in the former case. Field Emission Scanning Electron Microscopy (FESEM) and Electrochemical Impedance Spectroscopy (EIS) techniques have been employed to carry out the physicochemical characterization of the electrodes and to assess the electrochemical interfaces within the system, respectively. The observed findings definitely encourage us to proceeding with our study on GDL-supported catalyst for the continuous ECR-CO2 in the presence of ILs solutions and offers openings for a large-scale deployment. Acknowledgments The financial support of the SUNCOCHEM project (Grant Agreement No 862192) of the European Union’s Horizon 2020 Research and Innovation Action programme is acknowledged. References IEA. Global Energy Review: CO2 Emissions in 2021. (2021).Kunene, T., Atifi, A. & Rosenthal, J. Selective CO2 Reduction over Rose’s Metal in the Presence of an Imidazolium Ionic Liquid Electrolyte. ACS Appl. Energy Mater. 3, 4193–4200 (2020).Yang, K., Kas, R., Smith, W. A. & Burdyny, T. Role of the Carbon-Based Gas Diffusion Layer on Flooding in a Gas Diffusion Electrode Cell for Electrochemical CO2 Reduction. ACS Energy Lett. 6, 33–40 (2021).

Design, Performance and Economic evaluation of a 4kW Grid-interactive Solar PV Rooftop in Odisha using Pvsyst

The global decline of fossil fuels has required the development of alternative energy sources to satisfy the electricity demand. This article assesses and inaugurated the viability of grid-interactive photovoltaic systems providing electricity to a residential load. Since the average solar irradiation in Odisha is 1156.39 W/m2, a 4-kW rooftop solar photovoltaic system can produce 17.8 kWh of electricity per day (5.5 sunshine hours). Carbon Dioxide (CO2) emissions are reduced by 113 tonnes for every 4 kWp produced, which is equal to planting 181 trees. This 4kW device is analyzed with a PVsyst (V7) program for a residential load consumption of kWh/day. The device consists of 16 photovoltaic modules, each with a 320 Wp value, that are arranged in two strings of eight modules each. The efficacy of the photovoltaic arrays, surplus energy pumped into the grid, usable AC energy, efficiency ratio, and various losses occurring in the photovoltaic system are all evaluated in the simulation outcome. The paper promotes using photovoltaic systems as a cost-effective and environmentally friendly energy source.

Energy and Power Evolution Over the Lifetime of a Battery

ADVERTISEMENT RETURN TO ARTICLES ASAPPREVViewpointNEXTEnergy and Power Evolution Over the Lifetime of a BatteryFredrick OmenyaFredrick OmenyaPacific Northwest National Laboratory, Richland, Washington 99354, United StatesMore by Fredrick Omenya, Matthew PaissMatthew PaissPacific Northwest National Laboratory, Richland, Washington 99354, United StatesMore by Matthew Paiss, Xiaolin Li*Xiaolin LiPacific Northwest National Laboratory, Richland, Washington 99354, United States*[email protected]More by Xiaolin Lihttps://orcid.org/0000-0002-7728-0157, and David Reed*David ReedPacific Northwest National Laboratory, Richland, Washington 99354, United States*[email protected]More by David ReedCite this: ACS Energy Lett. 2023, 8, XXX, 2707–2710Publication Date (Web):May 24, 2023Publication History Received28 March 2023Accepted9 May 2023Published online24 May 2023https://doi.org/10.1021/acsenergylett.3c00660© 2023 American Chemical SocietyRIGHTS & PERMISSIONSArticle Views-Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (1 MB) Get e-Alerts Get e-Alerts