Electrochemical Performance Of Cell Research Articles

A Universal Interfacial Reconstruction Strategy Based on Converting Residual Alkali for Sodium Layered Oxide Cathodes: Marvelous Air Stability, Reversible Anion Redox, and Practical Full Cell.

Mn-based layered oxide cathodes have attracted widespread attention due to high capacity and low cost, however, poor air stability, irreversible phase transitions, and slow kinetics inhibit their practical application. Here, we propose a universal interfacial reconstruction strategy based on converting residual alkali to tunnel phase Na0.44MnO2 for addressing the above mentioned issue simultaneously, using O3 NaNi0.4Fe0.2Mn0.4O2@2 mol % Na0.44MnO2 (NaNFM@NMO) as the prototype material. The optimized material exhibits an initial capacity and energy density comparable with lithium-ion batteries. The reversible anionic redox behavior and charge compensation mechanism of NaNFM@NMO were analyzed and verified by soft X-ray absorption spectrum and in situ X-ray absorption spectrum. Due to the intrinsic stability of the tunnel structure, excellent air stability and highly reversible structure evolution of the NaNFM@NMO cathode material are achieved, which are confirmed by contact angle test, rigorous aging test, and in situ X-ray diffraction. More importantly, the NaNFM@NMO cathode demonstrates a great match with the nonpresodiated hard carbon anode and shows excellent electrochemical performance of the full cell. Additionally, such a strategy could be also applied to modify P2-type cathodes, showing superior universality and good prospects in industrialized production. Overall, the proposed strategy could improve air stability while remaining interfacial and bulk stable simultaneously and will open up a whole new field for the optimization of other electrode materials.

Enhanced Performance of Lithium-Sulfur Batteries Using Construction Wastes: A Sustainable Approach to High-Loading Sulfur Cathodes.

Advancing lithium-sulfur battery technology requires addressing both extrinsic cell-fabrication and intrinsic material challenges to improve efficiency, cyclability, and environmental sustainability. A key challenge is the low conductivity of sulfur cathodes, which is typically managed by incorporating conductive carbon materials. These materials enhance the performance of sulfur cathodes by facilitating high sulfur loading and improving polysulfide retention. In line with green chemistry principles and circular economy concepts, this study explores the use of recycled materials-specifically recycled quartz and board-as substrates for graphene coatings in lithium-sulfur cells. Recycled quartz bricks and blocks, predominantly SiO2, and recycled shelf boards, rich in Al2O3, are successfully coated with graphene, which significantly improves polysulfide adsorption and overall battery performance. The graphene-coated quartz exhibits high sulfur loading (8 mg cm-2), exceptional charge-storage capacity (1,114 mA·h g-1), and long cycle stability (200 cycles) with an energy density of 19 mW·h cm-2. This approach enhances the electrochemical performance of the lithium-sulfur cells and also aligns with sustainability goals by repurposing waste materials and minimizing environmental impact. This novel methodology demonstrates that integrating recycled materials can effectively address key challenges in lithium-sulfur battery technology, advancing both performance and environmental sustainability.

The influence of operating parameters on the performance of PEMWE electrolytic cell

Proton exchange membrane (PEM) is considered the most promising green hydrogen production technology in the future. The proton exchange membrane electrolysis cell (PEMEC) involves a complex process of multiple physical fields, including charge transfer, gas transfer, and heat transfer, during operation. Increasing the inlet water flow rate within a certain range is beneficial for increasing the output performance of the electrolysis cell and can also reduce the average temperature of the proton exchange membrane. But when the inlet flow rate increases to a certain amount, it has no effect. As the electrolysis voltage increases, the electrochemical performance of the electrolysis cell also increases, and the temperature of the proton exchange membrane and the current density of the catalytic layer also increase with the increase of voltage.

In-situ construction of high-performance artificial solid electrolyte interface layer on anode surfaces for anode-free lithium metal batteries

The electrochemical performance of lithium metal batteries (LMBs) was hampered by the uncontrolled growth of lithium (Li) dendrites. To address this issue, the extensive application of artificial solid electrolyte interphase (SEI) coatings on anode surfaces emerged as an effective solution. Electrospinning, as an innovative technique for fabricating artificial SEI layers on the surface of copper (Cu) foil, effectively mitigated Li volume strain during cycling. In this study, an electrospun organic–inorganic composite nanofiber membrane was in-situ fabricated on Cu foil, serving as an artificial SEI layer (CuWs) for anode-free LMBs (AF-LMBs) to enhance battery performance. Lithiophilic polyvinylpyrrolidone was used as the polymer matrix, and Cu nitrate served as the inorganic functional particles capable of in-situ redox reactions. The CuWs with their three-dimensional (3D) network structure accommodated electrode volume changes and suppressed Li dendrite growth during Li deposition and stripping. Additionally, CuWs facilitated the in-situ generation of Li nitrate (LiNO3), which helped stabilize SEI layer and enhance Li utilization. The release sites of LiNO3 on the nanofibers enabled the in-situ reduction of metallic Cu, providing nucleation sites for Li deposition and forming the 3D ion–electron hybrid conductive networks. This CuWs layer reduced interfacial resistance and nucleation barriers, promoting uniform Li+ distribution on the anode surface. Li-Cu cells incorporating CuWs exhibited remarkable cycling stability, enduring over 460 cycles at 1.0 mA cm−2 and 1.0 mAh cm−2 with an average Coulombic efficiency of over 98.6 %. In Li-poor cells, the LFP|PE|CuWs achieved stable cycling for more than 30 cycles at 1.0 C, with a capacity retention rate of 92.0 %. These findings demonstrated that the CuWs membrane significantly enhanced the electrochemical performance of Li-poor cells and provided a novel artificial SEI protective strategy for advanced AF-LMBs with high energy density.

O-PHTHALALDEHYDE CROSS-LINKED CHITOSAN MEMBRANE AS A QUASI-SOLID-STATE ELECTROLYTE FOR SUPERCAPACITORS

This study reports a stepwise formation method of a chitosan membrane cross-linked with o-phthalaldehyde and its use as a polymer matrix in a quasi-solid-state-electrolytebased supercapacitor. The proposed method of cross-linking in chitosan solution and evaporation of the solvent yielded a homogeneous and durable chitosan-o-phthalaldehyde membrane, which, after dipping in an aqueous 2 M lithium sulfate solution, formed a quasi-solid-state-electrolyte (CS/OPAQSSE). The prepared CS/OPA-QSSE was then used in an electric double layer capacitor (EDLC) cell to study its electrochemical properties. The electrochemical performance of the EDLC cell was determined by using the electrochemical impedance spectroscopy, cyclic voltammetry and galvanostatic charging/discharging techniques. The results showed that the EDLC cell with the CS/OPA-QSSE is a fully functional and efficient device. The specific capacitance values calculated for the CS/OPA-QSSE EDLC (up to 115 F g–1) always surpassed the reference cell based on a commercial glass fibre separator Therefore, the proposed chitosan modification can be considered as a future alternative to produce other polysaccharide-based materials for electrochemical use.

Bidirectional pH Buffer Effect Facilitates High-Reversible Aqueous Zinc Ion Batteries.

Aqueous zinc ion batteries (AZIBs) stand out from the crowd of energy storage equipment for their superior energy density, enhanced safety features, and affordability. However, the notorious side reaction in the zinc anode and the dissolution of the cathode materials led to poor cycling stability has hindered their further development. Herein, ammonium salicylate (AS) is a bidirectional electrolyte additive to promote prolonged stable cycles in AZIBs. NH4 + and C6H4OHCOO- collaboratively stabilize the pH at the interface of the electrolyte/electrode and guide the homogeneous deposition of Zn2+ at the zinc anode. The higher adsorption energy of NH4 + compared to H2O on the Zn (002) crystal plane mitigates the side reactions on the anode surface. Moreover, NH4 + is similarly adsorbed on the cathode surface, maintaining the stability of the electrode. C6H4OHCOO- and Zn2+ are co-intercalation/deintercalation during the cycling process, contributing to the higher electrochemical performance of the full cell. As a result, with the presence of AS additive, the Zn//Zn symmetric cells achieved 700h of highly reversible cycling at 5mA cm-2. In addition, the assembled NH4V4O10(NVO)//Zn coin and pouch batteries achieved higher capacity and higher cycle lifetime, demonstrating the practicality of the AS electrolyte additive.

Research on performance optimization of electrolytic cell: Non-parameter topology and parameter optimization

The technology of water electrolysis for hydrogen production converts renewable energy into hydrogen, enabling efficient storage and utilization of clean energy. The key to enabling the large-scale development of water electrolysis technology lies in enhancing the performance of electrolytic cells and minimizing energy consumption. The mastoid process structure obviously influences the electrolytic cell's flow and electrochemical performance. Therefore, this paper studied the sensitivity of the mastoid process structure to the optimization target, designed the shape topology and the parameter optimization structure, and further analyzed the influence of the two optimization methods on the flow and electrochemical performance of the electrolytic cell based on the multi-physics coupling model. The results show that under the same deformation area, the pressure drop of the topology and the parameter optimization structure is reduced by 17.17 % and 11.89 % compared with that of the original structure. The electrochemical properties were almost unaffected, and the change value was less than 0.1 %. Topology optimization design can achieve optimal performance within limited deformation constraints, and parameter optimization design is more conducive to industrial processing.

Roll-to-roll fabrication and characterization of ultra-thin ceramic-coated separator for high-energy-density lithium-ion batteries

Ceramic-coated separators (CCSs) used in lithium-ion batteries (LIBs) play an important role in ensuring the safety of LIBs. However, conventional CCSs fabricated by coating the slurry consisting of ceramic particles and binder have limitations due to the micrometer-thick ceramic coating layer (CCL), compromising the energy density and power capabilities of LIBs. To address this relationship, ultra-thin CCSs fabricated by the sputtering process have attracted attention due to their high thermal stability even with nanometer-thick CCL. Nevertheless, batch-type sputtering machines cannot provide roll-based CCSs for commercial LIBs. Herein, we demonstrate the continuous fabrication of ultra-thin CCS rolls with a pilot-scale direct current (DC) roll-to-roll sputtering process. The ionic conductance and thermal stability are compared with the slurry-based CCS by controlling the coating thickness through the line speed. In addition, the electrochemical performance of the pouch cell (LiNi0.6Co0.2Mn0.2O2/graphite, 550 mAh) is evaluated to confirm the applicability of the roll-to-roll sputtered ultra-thin, binder-free CCS (R2R-UB-CCS) to LIBs. Owing to the nanometer-thick CCL, the pouch cell with the R2R-UB-CCS shows higher power capabilities than the bare polyethylene (PE) separator and slurry-based CCS. Thus, the roll-to-roll sputtering process for large-scale, high-speed mass production of ultra-thin CCS has the potential for high safety and high-energy-density LIBs.

Expanded Illite Filler in UV-Curable Polymer Electrolytes for All-Solid-State Li-Ion Batteries

In this study, we explored the potential of illite sourced from Yeongdong-eup, South Korea, as a filler in polymer electrolytes for all-solid-state Li-ion batteries. The illite was expanded (EI) by acid treatment and UV curing was employed to synthesize the polymer electrolytes. The Li+ ionic conductivity of the polymer electrolytes was measured at various EI contents, revealing the highest conductivity of 1.08 × 10−2 S cm−1 at 4 wt% of the EI. The electrochemical performance of NMC cells assembled with the EI-incorporated polymer electrolyte showed a good discharge capacity of over 158.6 mAh g−1 with a coulombic efficiency of 99%. These findings demonstrate the significant potential of EI as a sustainable and efficient filler material for enhancing the performance of polymer-based all-solid-state Li batteries. This study highlighted the applicability of illite sourced from South Korea and its potential contribution to the development of polymer-based all-solid-state batteries.

Mo3P/Mo heterojunction for efficient conversion of lithium polysulfides in high-performance lithium-sulfur batteries.

Realizing efficient immobilization of lithium polysulfides (LiPSs) as well as reversible catalytic conversion between LiPSs and the insoluble Li2S is vital to restrain the shuttle effect, which requires highly reactive catalysts for high-performance Li-S batteries. Here, three-dimensional ordered porous Mo-based metal phosphides (3DOP Mo3P/Mo) with heterogeneous structures were fabricated and utilized as separator-modified coatings for Li-S batteries to catalyze the conversion of LiPSs. The adsorption, catalytic and electrochemical performance of the corresponding cells were compared among 3DOP Mo3P/Mo and 3DOP Mo, by kinetic and electrochemical performance measurements. It was found that the cell with 3DOP Mo3P/Mo modified separator deliver better electrochemical performance, with a high specific capacity of 469.66mAh g-1 after 500 cycles at a high current density of 1°C. This work provides an idea and a guideline for the design of the separator modification for high-performance Li-S batteries.

3D Printed Symmetric Carbon Supercapacitors: A Study Comparing Electrochemical Performance and Cycle Life Depending on 3D Printing Technique and Materials

With the ongoing global energy crisis, producing reliable and efficient methods of energy storage remains an integral part of cutting-edge materials research. Within this topic, 3D-printing (also known as additive manufacturing) is evolving from a niche hobby to a reliable scientific tool for materials science research [1-3]. 3D-printing energy storage materials provides unparalleled levels of customisation [4-9] and freedom of design, while also eliminating waste material during the manufacturing process.3D-printing energy storage materials has been widely covered, but usually just focuses on one method of 3D-printing. Directly comparing more than one 3D-printing method within a single energy storage study is far more seldom researched. This work directly compares the electrochemical performances of symmetric carbon-based supercapacitor devices made using two 3D-printing techniques, SLA (stereolithography) and FDM (fused deposition modelling). Two cell types are made in this study, one with gold-sputtered SLA-printed current collectors, the other with conductive PLA (polylactic acid) FDM-printed current collectors. Carbon-based electrode (various combinations of SWCNT, GNP, Super-P, PVDF) slurries and aqueous 6M KOH electrolyte are implemented in these cells. The benefits and limitations of these 3D-printing methods are directly compared, with the electrochemical performance of the supercapacitor cells being analysed using cyclic voltammetry and galvanostatic charge-discharge tests.The sputtered conductive SLA current collector cells display better conductivity and more ideal rectangular cyclic voltammetry curves for electronic double-layer capacitors (EDLCs) but suffer from poor cycle life in initial experiments (~5,000 charge-discharge cycles before losing all specific capacitance). The FDM current collector cells have poorer conductivity, less ideal cyclic voltammetry curves, and are less structurally sound (causing some electrolyte leakage over long term cycling) but offer extremely stable cycle life for supercapacitor cells, retaining most of their specific capacitance after 100,000 charge-discharge cycles. The cycle lives of the gold-sputtered SLA current collector cells are greatly improved after several changes made during the study, such as reducing the voltage window from 0.0-1.0 V to 0.2-0.7 V, and exploring additives for the carbon-based slurry electrodes, such as Super-P and PVDF (polyvinylidene fluoride).

Confocal Raman Microscopy – Shedding Light on the Ionomer Properties of PFSA Membranes

Perfluorinated sulfonic acid (PFSA) polymers are the state-of-the-art material for the proton exchange membrane (PEM) in various electrochemical energy conversion devices, e.g., PEM fuel cells, PEM water electrolyzers, or redox flow batteries, combining chemical and mechanical durability with high proton conductivity.The most prominent example of a PFSA material is NafionTM, which is a so-called long side chain (LSC) ionomer due to its comparably long side chain between the polymer backbone and the charged sulfonyl end group. On the other hand, short side chain (SSC) ionomers like Aquivion® and 3M Ionomer or composite membranes are promising approaches to improve performance in harsh conditions, such as low humidity or high operating temperatures.1 SSC PEMs feature increased water uptake, proton conductivity,2 and crystallinity3 compared to LSC PEMs. Composite PEMs can be specifically tailored to the required operating conditions by carefully designing the interlayers or additives. As the performance and longevity of electrochemical cells are a delicate convolution of various (composite) membrane properties and parameters, a method for evaluating ionomer membrane properties is crucial for rationally engineering optimized PEMs.Here, we use confocal Raman microscopy (CRM) to investigate application-relevant properties of PFSA PEMs and for high-resolution imaging of composite membranes.4 Thus, the high spatial resolution of confocal optical microscopy and the chemical sensitivity of Raman scattering are combined in a single measurement approach. NafionTM, 3M Ionomer, and Aquivion® at varying equivalent weights (EW) feature distinctive Raman spectra (Fig. 1) that show characteristic spectral changes depending on the ionomer’s side chain structure and EW. We show that the EW of these PFSA types can be reliably measured using Raman spectroscopy. Further, parameters such as swelling, ionizable group content, and water uptake can be quantified by CRM non-destructively and contact-free. The diffraction-limited resolution of CRM of less than 2 µm enables a view of the local distribution of these properties and, therefore, allows to image and analyze composite membranes. In summary, we comprehensively study ionomer properties of (composite) membranes and establish CRM as a powerful platform for characterizing advanced PEMs for electrochemical energy deviceReferences A. S. Aricò, A. Di Blasi, G. Brunaccini, F. Sergi, G. Dispenza, L. Andaloro, M. Ferraro, V. Antonucci, P. Asher, S. Buche, D. Fongalland, G. A. Hards, J. D. B. Sharman, A. Bayer, G. Heinz, N. Zandonà, R. Zuber, M. Gebert, M. Corasaniti, A. Ghielmi and D. J. Jones, Fuel Cells, 10(6), 1013–1023 (2010).Y.-C. Park, K. Kakinuma, H. Uchida, M. Watanabe and M. Uchida, Journal of Power Sources, 275, 384–391 (2015).K. D. Kreuer, M. Schuster, B. Obliers, O. Diat, U. Traub, A. Fuchs, U. Klock, S. J. Paddison and J. Maier, Journal of Power Sources, 178(2), 499–509 (2008).M. Maier, D. Abbas, M. Komma, M. S. Mu'min, S. Thiele and T. Böhm, Journal of Membrane Science, 669, 121244 (2023). Figure 1

A Thermal Tanks-in-Series Model for Simulating over-Discharge Cycling in Lithium-Ion Batteries

Energy storage will play a crucial role in the transition to clean and renewable sources of energy production to meet future consumption demands.1 Lithium-ion (Li-ion) batteries are widely adopted due to their high energy density, low self-discharge rate and fast charging capabilities for applications like electric vehicles and grid storage.2 Li-ion batteries for high voltage operations, where several cells are connected in series, can experience inadvertent over-discharge due to differences between cells3,4. These differences can arise due to many reasons including changes in internal resistance and deviation in electrochemical degradation that can cause divergence of cell open circuit potentials. Over-discharge is a condition when the manufacturer recommended lower voltage limit is crossed while discharging4, which results in various side effects such as electrolyte decomposition, capacity degradation, cathode morphology change and possible internal short circuit3,5. Increase in anode potential during over-discharge leads to copper dissolution from the anode current collector and subsequent plating within cell components. The Solid Electrolyte Interface (SEI) can decompose during excessive deintercalation and reform during charging, reducing the lithium inventory. Excessive heat generation during cycle life testing after occurrences of over-discharges has been found in some cases to lead to temperatures >150 °C6,7.Temperature plays a key role in the electrochemical performance of individual cells, affecting the diffusivities of ions, kinetics of reactions and rate of degradation of the battery. A physics-based modeling approach coupled with a thermal model can be employed to understand the effect of over-discharge on the electrochemical behavior of Li-ion batteries and provides insights into the interplay of various degradation mechanisms that cause capacity fade.The Thermal Tank-In-Series9,10(TTiS) model is a systematically volume-averaged form of the standard pseudo-2-dimensional (p2D)11 model with energy balance equations for the current collectors, cathode, separator and anode. This reduces the number of equations in the model and improves computational speed while maintaining accuracy, as it is sensitive to changes in the battery’s state of charge (SOC) and cell temperature, which helps predict the overpotential changes to the cell electrodes and thermodynamics.We use the TTiS model to identify the dominant fade mechanisms in 3 sets of experimental cycling and temperature data for the: i) normal operating window (2.5V – 4.2V), ii) 5 initial cycles of over-discharge (1.5V – 4.2V) followed by normal operation until 20% capacity fade and iii) 5 cycles of periodic over-discharge every 20 cycles, until 20% capacity fade. Analysis on the effect of C-rate, ambient temperature and voltage window of operation will facilitate understanding the temperature behavior and overpotentials in a cell sandwich. Key considerations required in extending a model to simulate over-discharge will also be examined. References S.P. S. Badwal, S. S. Giddey, C. Munnings, A. I. Bhatt, and A. F. Hollenkamp, Frontiers in Chemistry, 2, 28 (2014).G. Pistoia. Lithium-Ion Batteries: Advances and Applications. First ed. Elsevier, Amsterdam (2014).R. Guo, L. Lu., M. Ouyang, X. Feng. Sci Rep 6, 30248 (2016).G.Zhang, X. Wei, S. Chen, J. Zhu, G. Han, and H. Dai. J. Power Sources, 521, 230990. (2022).C. Fear, D. Juarez-Robles, J. A. Jeevarajan, and P. P. Mukherjee, J. Electrochem. Soc., 165, A1639–A1647 (2018).D. Juarez-Robles, Purdue Univ. Ph.D. Thesis (2019).H. Maleki and J. N. Howard, J. Power Sources, 160, 1395–1402 (2006).H. Liu, Z. Wei, W. He, and J. Zhao, Energy Convers. Manag., 150, 304–330 (2017).A. Subramaniam, S. Kolluri, S. Santhanagopalan, and V. R. Subramanian, J. Electrochem. Soc., 167, 113506 (2020).A. Subramaniam, S. Kolluri, C. D. Parke, M. Pathak, S. Santhanagopalan, and V. R. Subramanian, J. Electrochem. Soc., 167, 013534 (2020).M. Doyle, T. F. Fuller, and J. Newman, J. Electrochem. Soc., 140, 1526 (1993)

Electrochemical Performance of Lithium-Ion Cells with Lithium- and Manganese- Rich Oxide Cathodes

State-of the-art (SOA) lithium-ion batteries (LIBs) being developed for transportation applications contain a transition metal (TM) oxide cathode and a graphite anode; both serve as host-matrices to house lithium ions during battery operation. The cathodes typically contains Li1+xNiaCobAlcO2 (NCA) or Li1+xNiaMnbCocO2 (NMC) oxides: both oxide chemistries contain Co, which is known to preserve the layered structure during lithium extraction/insertion reactions. However, the possibility of a global Co shortage and soaring costs has galvanized the LIB community to explore sustainable cathode chemistries, while maintaining cell performance (energy/power densities), safety and cycle/calendar life. In this context the U.S. Department of Energy (DOE) initiated the Earth-Abundant Cathode Active Material (EaCAM) Program for the development of sustainable cathode chemistries, based on earth-abundant elements.Materials of particular interest to the EaCAM program are the x Li2MnO3 ● (1-x) LiMnaNibZcO2 composites; here Z refers to various elements that could be included in the oxide structure. These lithium- and manganese- rich materials are considered attractive candidates because of their high specific capacities, zero cobalt content, and lower costs compared to the SOA oxides. We have been examining the electrochemical behavior of cells with these oxides, with a particular focus on the 0.3 Li2MnO3 ● 0.7 LiMn0.5Ni0.5O2 (LMR) compound.During this presentation, we will show results from battery cells, containing LMR cathodes and either graphite or lithium-titanate anodes. In particular, the use of a microprobe reference electrode to monitor the cathode and anode potentials will be discussed. The effect of activation on cell performance and the performance loss characteristics during cycling will be highlighted. We will show how cell impedance is affected by voltage hysteresis and the voltage fade that results from cycling. Our ultimate goal is to identify constituents and mechanisms responsible for the cell performance loss and develop solutions to mitigate this degradation.Acknowledgement: This document has been created by UChicago Argonne, LLC, Operator of Argonne National Laboratory (“Argonne”). Argonne, a U.S. Department of Energy Office of Science laboratory, is operated under Contract No. DE-AC02-06CH11357.

Strategy to Enhance Air Electrode Performance and Durability in Soe and Co-Soe Modes: Composite Electrode with a Gradually Changing Composition

Among the key challenges of the Solid Oxide Cell (SOC) is stable, long-term operation in electrolysis (SOE, Solid Oxide Electrolysis), and co-electrolysis (co-SOE) modes. Many factors impact the SOC’s lifespan, i.e., the chemical composition of the fuel and air electrode, the type of the cell, and working conditions (e.g., current density, temperature). Therefore, the development of high-performance and durable cells seems to be crucial, as SOE/co-SOE systems may play an important role in the ongoing transformation toward a climate-neutral economy (low-emission hydrogen production; efficient utilization of CO2and renewable energy) [1,2].One of the crucial degradation mechanisms of SOC in electrolysis/co-electrolysis mode is the delamination of the air electrode, caused by the accumulation of high oxygen partial pressure on the interphase of the electrolyte, the formation of additional phases, and/or reaction of voids/cracks in the electrolyte or buffer layer [2,3]. A strategy to mitigate the risk of air electrode delamination is to use composite electrode based on the buffer layer material (GDC- Gd0,1Ce0,9O2) and state-of-the-art electrode – LSC (La0,6Sr0,4CoO3-δ), as it will lower the effect of the thermal expansion mismatch between the electrode and buffer layer/electrolyte. Moreover, by manipulating the microstructure of the electrode, e.g., by introducing a pore-forming agent, it is possible to ensure fast and effective collection of oxygen generated during operation in the SOE/co-SOE mode on the air side (preventing potential differences leading to the stresses on the electrode-electrolyte interface).In this study, the electrochemical performance of solid oxide cells with a modified, gradually changing composite LSC-GDC air electrode was verified in electrolysis and co-electrolysis modes. The following air electrode compositions were proposed for cell preparation: type 1: 1st layer 50LSC:50CGO, 2nd layer: 75LSC: 25GDC, 3rd layer: LSC, type 2: 1st layer 75LSC:25CGO, 2nd and 3rd layers: LSC with PMMA as a pore former; type 3: 1st layer 75LSC:25CGO, 2nd and 3rd layers: 90LSC:10GDC, and type 4: 1st layer 85LSC:15CGO, 2nd layer: 90LSC:10GDC; 3rd layer: LSC with PMMA as a pore former. The proposed air electrode was tested at the single-cell level (cells size of 50 mm x 50 mm), and the most promising solutions were implemented in the SOC stack (a stack consisting of 3-5 cells with a size of 110 mm x 110 mm). The electrochemical analysis of the developed cells includes measurements of the j-V dependences and EIS spectra under different modes (SOE and co-SOE), various temperatures, current densities, and different gas flows delivered at the air side of the cell. The microstructure, morphology, and composition of the prepared cells and samples after testing were analyzed using SEM, SEM-EDS, and, for selected samples, the FIB-SEM method. The obtained results showed that by a gradually changing the electrode composition, specifically by reducing the GDC content in the electrode, it is possible to obtain a stable electrode (a strategy to prevent air electrode delamination) with high catalytic activity in both electrolysis and co-electrolysis modes. The composite GDC-LSC electrodes with various compositions seem to be promising air electrodes for SOE and co-SOE systems. The study achieves relatively high current densities compared to the SoA cells, with only negligible degradation changes observed after long-term testing (>300 h in single cell configuration). Acknowledgments The presented research was financially supported by: the National Centre for Research and Development, Poland, within project no. LIDER/1/0003/L-12/20/NCBR/2021, which focuses on research related to composite electrodes. Anna Niemczyk acknowledges support from the Foundation for Polish Science (FNP) through a scholarship from the START program. References B. Mogensen et al., Clean Energy 3 (2019) 175; DOI: 10.1093/ce/zkz023Hauch, P. Blennow, Solid State Ionics 391 (2023) 116127; DOI: 10.1016/j.ssi.2022.116127Subotić, C. Hochenauer, Progress in Energy and Combustion Science 93 (2022) 101011; DOI: 10.1016/j.pecs.2022.101011

Investigating Temperature-Dependent Dynamics of SEI Growth and Battery Degradation

Several studies have contributed to the current understanding of the temperature-dependent behavior of solid-electrolyte interphase (SEI) formation in lithium-ion batteries and its impact on battery capacity and lifespan. Liu et al. developed a thermal-electrochemical model that revealed the complex interplay between diffusivity, reaction kinetics, and temperature on SEI growth1. Leng et al. presented an electrochemistry-based electrical model to examine the temperature's effect on battery aging2. Alipour et al. reviewed temperature-dependent electrochemical properties3, while Lubhani Mishra et al. provided a detailed physics-based analysis of battery degradation and temperature inhomogeneities4. These studies collectively indicate higher temperatures accelerating and promoting growth of compact and less permeable SEI structures leading to an increase in capacity loss and cell resistance, and lower temperatures resulting in slow ionic transport through the SEI also causing higher ohmic loss. In the present work, we study SEI growth and resulting effect on battery capacity fade using continuum scale modeling under the assumption of constant battery cell temperature as well as considering actual dynamically changing temperature data from experiments. SEI growth under these two considerations is compared and the comparison is used in determining scenarios where considering dynamically varying temperature is crucial for accuracy. The detailed analysis of the internal states from the simulation results contributes to the understanding of the effect of the thermal dynamics on battery cell degradation due to SEI growth. To achieve these objectives, a physics-based model, specifically the Single Particle Model (SPM), is utilized. The model uses temporal temperature data obtained from past experimental studies as well as temperature dependent properties of SEI provided in the literature as inputs for this investigation. The ultimate aim of this study is to better understand how temperature influences SEI characteristics, thereby contributing to improved battery performance and longevity across diverse thermal environments. References Liu, L., Park, J., Lin, X., Sastry, A. M., & Lu, W. (2014). A thermal-electrochemical model that gives spatial-dependent growth of solid electrolyte interphase in a Li-ion battery. Journal of power sources, 268, 482-490.Leng, F., Tan, C. M., & Pecht, M. (2015). Effect of temperature on the aging rate of Li-ion battery operating above room temperature. Scientific reports, 5(1), 12967.Alipour, M., Ziebert, C., Conte, F. V., & Kizilel, R. (2020). A review on temperature-dependent electrochemical properties, aging, and performance of lithium-ion cells. Batteries, 6(3), 35.Mishra, L., Subramaniam, A., Jang, T., Garrick, T. R., & Subramanian, V. R. (2022, October). Model Development for Temperature-Dependent Degradation in Large Format Lithium-Ion Batteries. In Electrochemical Society Meeting s 242 (No. 28, pp. 1075-1075). The Electrochemical Society, Inc.

Microstructural Characterization of Porous Transport Layer Coatings

The porous transport layer (PTL) is a key component in polymer electrolyte membrane (PEM) water electrolyzers and serves the role of controlling the transport of reactants and products to and from the anode. Maintaining a low interfacial contact resistance between the titanium (Ti) fiber or sinter PTL and the iridium (Ir) anode catalyst is critical to maintaining the performance of the electrolyzer cell. This requires costly precious metal coatings, typically Pt, to inhibit the formation of native oxide layers during long-term cell operation. Strategies to reducing the thickness of these costly coatings including surface treatments, such as etching and abrasion, alternative low-cost coating materials, and implementation of microporous layers. It is crucial to understanding the morphologies and degradation mechanisms of these new strategies in order to accelerate the development of cheaper, more robust PTL coatings.In this work, correlative ex situ characterization methods, including laser confocal microscopy (LCM), focused ion beam (FIB), scanning electron microscopy (SEM), time-of-flight secondary ion mass spectrometry (ToF-SIMS), atomic force microscopy (AFM), X-ray photoelectron spectroscopy (XPS) and scanning transmission electron microscopy (STEM), are utilized to explore the impact surface treatments, such as etching and abrasion, on the Pt coatings uniformity and surface roughness. The thickness, local topography, and continuity of the Pt coating were quantified and correlated with interfacial contact resistance and electrochemical cell performance measurements. Changes to the thickness and composition of the coatings and oxide layers after single-cell tests will also be reported. Overall, these findings aim to guide the development of PTL treatments and coatings, ensuring the creation of highly durable and efficient PEM water electrolyzers that align with the U.S. Department of Energy's Hydrogen Shot goal of reducing the cost of clean hydrogen production to $1 per kilogram by 2031.Funding for this work was provided by U.S. Department of Energy Office of Energy Efficiency and Renewable Energy, Hydrogen and Fuel Cell Technologies Office through the H2NEW Consortium. Electron microscopy research conducted as part of a user project at the Center for Nanophase Materials Sciences (CNMS), which is a US Department of Energy, Office of Science User Facility at Oak Ridge National Laboratory.

(Invited) Electrosynthesis of Carbon Dioxide to Ethylene

Electrochemical production of hydrocarbons provides a pathway for connecting renewable energy generation with chemical production. In this work, we present research on the targeted electrochemical reduction of carbon dioxide to ethylene, which has a global production volume of over 200 metric tonnes per year. The selectivity of carbon dioxide to ethylene is heavily dependent on cell architecture, surface interfaces, and operating conditions. We explore the tradeoffs of using a zero-gap cell design, and demonstrate the production of ethylene with greater than 30% selectivity at 200 mA/cm2 with an uncompensated full cell voltage of 2.7 V. We also present modifications to a copper catalyst cathode, and the effects of conditioning and variable operation on the electrochemical cell performance including selectivity and durability. Leveraging technoeconomic analyses, we will present the projected costs of this pathway for producing ethylene and conclude with a discussion on long-term operation failure modes which greatly impact the future feasibility of this technology. Figure 1

Implementing Substrate Treatments to Enhance Adhesion and Facilitate Cyrene as an NMP Alternative for Sustainable Printed Nickel–Manganese–Cobalt‐Based Battery Cathodes

This study proposes a greener approach for electrode preparation using cyrene, a bio‐derived and fully biodegradable green solvent, as a potential N‐methyl‐2‐pyrrolidone substitute for fabricating high‐performance nickel–manganese–cobalt oxide (NMC88) lithium‐ion battery cathodes by screen‐printing method. This study also investigates the replacement of the polyvinylidene fluoride (PVDF) binder with Arkema Kynar HSV1810 homopolymer, a crucial substitution for enabling the effective utilization of cyrene, addressing the solvent inadequacy associated with PVDF dissolution. Alongside the ink formulation, the electrode preparation process is optimized by investigating current collector surface treatments using plasma, ultraviolet, and citric acid to enhance substrate wetting, leading to improved printability, adhesion, and cathode layer performance. Cyrene‐based screen‐printed NMC cathodes are analyzed using various characterization techniques, including microscopy, optical profilometry, scanning electron microscopy, adhesion tests, and electrochemical performance tests for assembled batteries. The results demonstrate that cyrene‐based slurries exhibit improved wettability and adhesion on substrates/current collectors when surface treatments are applied. Furthermore, the electrochemical performance of cells based on surface‐treated NMC88 electrodes prepared with cyrene shows adequate cycling performance and rate capability. As a proof of concept, the study presents an alternative green and sustainable approach for electrode preparation in screen‐printed Li‐ion batteries using cyrene.

The effect of pin-type flow field plate design on the current distribution in a H2-fed polymer electrolyte fuel cell

The flow field plate (FFP) design is a key factor for enhancing the electrochemical performance of Polymer Electrolyte Fuel Cells (PEFCs) through optimal reactants’ distribution, low-pressure drops, and efficient water removal. The effect of geometrical features of the pin-type FFP design on the electrochemical performance of a 48 cm2 H2-fed Fuel Cell (FC) was assessed through polarization curves recording and current and temperature distribution maps along the electrode active area. The study was performed by changing excess air stoichiometry and cathode relative humidity (RH). Low-pressure drops were measured using pin-type FFPs; regardless of geometrical features, they were one order of magnitude lower than those of a single-channel serpentine FFP. Channel width and number of pins greatly influenced the current distribution along the active area and, consequently, the electrochemical performance of FCs. In particular, the best electrochemical performance was reached at air stoichiometry 4 and cathode RH = 100 % by using FFP with the highest coverage factor (65 %) and the lowest channel width (1 mm). Current distribution maps demonstrated that this FFP geometry led to an almost homogeneous current distribution and efficient water removal also at high current density values. On the contrary, low coverage factor (45 %) and high channel width led to worse electrochemical performances due to an uneven reactants distribution and an inefficient water removal, causing cell flooding.