Battery Applications Research Articles

Scalable One-Pot Synthesis of Nanostructured P2-Type Na2/3Ni1/3Mn2/3O2 Cathode Material for High-Performance Na-Ion Batteries

Sodium-ion batteries (SIBs) based on sodium transition metal oxides are considered as a viable alternative to lithium-ion batteries (LIBs) for grid-scale energy storage. This is because the critical elements used in these SIBs, such as sodium, manganese, and nickel, are abundantly available, and their supply chain does not pose any geopolitical risk like lithium and cobalt used in common LIB cathodes.1 Among sodium transition metal oxide cathodes, the P2-type Na2/3[Ni1/3Mn2/3]O2 (NNMO) is a promising material due to its high operating voltage (up to 4.5 V vs Na/Na+) and high capacity. When cycled between 2-4.5 V vs Na/Na+, it has a capacity of 173 mAh/g.2 This combination of high operating voltage and high capacity allows NNMO to outperform common LIBs in terms of energy density. Therefore, SIBs based on NNMO cathode are a scalable alternative to LIBs.Unfortunately, the current method used to produce NNMO through solid-state conversion is a time and energy-intensive process. It requires a temperature above 800 degrees Celsius and takes at least 12 hours to make a single batch of NNMO. Moreover, NNMO formed using this method has large particle sizes of a few micrometers. In my presentation, I will introduce a new and highly scalable method for synthesizing NNMO. This method can create NNMO in less than 20 minutes, which is much faster than the usual 12+ hours required by existing methods. Additionally, our protocol produces Nano-NNMO particles with size in the sub-200 nm. Nanoscale NNMO is crucial because it enhances the electrochemical performance of the materials, which I will also discuss. Key words: Sodium-ion batteries, Na2/3[Ni1/3Mn2/3]O2, high capacity, nanoparticles, rapid synthesis. References (1) Wang, C.; Liu, L.; Zhao, S.; Liu, Y.; Yang, Y.; Yu, H.; Lee, S.; Lee, G.-H.; Kang, Y.-M.; Liu, R.; et al. Tuning local chemistry of P2 layered-oxide cathode for high energy and long cycles of sodium-ion battery. Nature Communications 2021, 12 (1), 2256. DOI: 10.1038/s41467-021-22523-3.(2) Zhang, J.; Wang, W.; Wang, W.; Wang, S.; Li, B. Comprehensive Review of P2-Type Na2/3Ni1/3Mn2/3O2, a Potential Cathode for Practical Application of Na-Ion Batteries. ACS Applied Materials & Interfaces 2019, 11 (25), 22051-22066. DOI: 10.1021/acsami.9b03937.

Aluminum Current Collector Corrosion Inhibition by a Newly Synthesized 5-Formyl-8-Hydroxyquinoline for Aqueous-Based Battery

Aluminum foil is the most frequently used as a cathodic current collector for batteries because of its high electrical conductivity, low cost, robust electrochemical properties, and low density. However, as next-generation batteries are created, serious corrosion poses new challenges to aluminum current collectors, especially with no effective additive in an aqueous electrolyte. A newly 5-formyl-8-hydroxyquinoline (FHQ) additive is designed and synthesized as an effective corrosion inhibitor for aluminum foil. The effect of FHQ on the corrosion of the Al current collector in an aqueous-based electrolyte has been investigated using electrochemical methods and spectroscopy techniques for assessing the corrosion inhibition efficacy and protective film formation on the Al surface. The Potentiodynamic polarization measurements indicated that the corrosion rate in millimeters per year (mmpy) of 1.37×10-3 is much lower in the aqueous electrolyte of 21 m LiTFSI with the FHQ additive than 2.29×10-2 in the electrolyte without an additive. Meanwhile, the Zn//LVPF configuration is developed as an efficient protocol to evaluate the corrosion prevention efficiency of inhibitors in an aqueous-based battery for the first time. The Zn//LVPF cell in the aqueous electrolyte with the FHQ additive provides much higher capacity retention and average Coulombic efficiency than the cell in the electrolyte in the absence of an additive. Interestingly, the Al corrosion prevention efficiency of the developed additive is also observed in an organic electrolyte-based battery. This work paves a new pathway to develop effective Al corrosion inhibitors for applications in lithium-ion batteries, especially in aqueous electrolytes. Keywords; Corrosion inhibitor; 8-hydroxyquinoline; 5-formyl-8-hydroxyquinoline; Doner/acceptor; HOMO-LUMO; Aluminum corrosion.

Synthesis and Characterizations of Novel Copolymers with Zwitterionic Moiety-Based Solid Polymer Electrolytes for Solid-State Lithium Metal Battery

Electric vehicles (EVs) have become the dominant choice in the automotive industry, displacing internal combustion engine vehicles (ICEVs) to some extent. The development of high-efficiency batteries is essential to meet these market demands. Conventional lithium-ion batteries (LIBs), which consist of a cathode, anode, separator, and liquid electrolyte (such as 1M LiPF6 in carbonate solvents), have been widely utilized in portable electronic devices, hybrid electric vehicles (HEVs), and EVs. This popularity is attributed to their relatively high energy density and extended cycle life [1]. However, LIBs with energy density exceeding 240 Wh kg-1 face challenges in terms of thermal stability, potentially leading to fire and explosions by overcharging or accidental cell penetration. This drawback significantly hinders their application in automotive settings [2, 3]. In response to these safety concerns, there is a shift towards incorporating solid-state electrolytes (SSEs) as a replacement for liquid electrolytes. SSEs include solid polymer electrolyte (SPE), inorganic solid electrolyte (ISE), and composite polymer electrolyte (CPE).Solid-state lithium metal batteries (SSLMBs) incorporating SPE hold significant promise for advancing energy storage technologies due to their high energy density and improved safety features. However, the low ionic conductivity and ionic transference number of SPEs present challenges in their application for solid-state batteries. This work focuses on designing novel copolymers with polar soft unit and zwitterionic unit to address these challenges.In this study, poly(ethylene glycol) methyl ether acrylate (PEGMEA) and sulfobetaine methacrylate (SBMA) were selected as the polar soft segment and zwitterionic unit, respectively. Various ratios of PEGMEA/SBMA in copolymers were synthesized and characterized, and the resultant SPEs consisting of resultant copolymers and lithium bis(trifluoromethanesulfonyl)imide (LiTFSI) were prepared. Subsequently, their electrochemical, thermal, mechanical, and morphological properties were systematically investigated. The copolymers-based SPEs exhibited improved electrochemical properties. The optimized SPE comprising the copolymer with the molar ratio of PEGMEA/SBMA = 1/3 and 50 wt% LiTFSI exhibited the ionic conductivity of approx. 2×10–4 S cm–1, lithium-ion transference number of approx. 0.3, Li+ diffusion coefficient of 15×10-12 cm² s-1, and oxidation stability of 5.2 V (vs. Li/Li+) at 25 oC. Additionally, the mechanical properties of such SPEs were assessed, showing improved tensile strength (up to approx. 6 MPa) and Young’s modulus (up to approx. 83 MPa) with increasing SBMA content. The selected SPE with the best electrochemical properties was sandwiched between a Li metal electrode and a LiFePO4 electrode to assemble a SSLMB. As a result, the discharge capacity (DC) at 0.1 C-rate and room temperature was approx. 170 mA h g–1. Furthermore, the DC at a 0.5 C-rate was approx. 146 mA h g–1, and the capacity retention of 70% obtained after 470 cycles. In summary, this work demonstrates the potential of tailored copolymers with zwitterionic moiety-based SPEs for SSLMB. The comprehensive characterization and performance assessments provide valuable insights into the design and optimization of polymer electrolytes for next-generation energy storage systems.The copolymers and corresponding SPEs underwent characterization through various techniques such as DSC, SEM, XRD, and FTIR. The Ionic conductivity of the SPEs was determined by analyzing the results obtained from EIS measurement. The lithium-ion diffusion coefficient (DLi+) for SPE in a symmetric SSLMB cell, Li/SPE/Li, was also calculated based on the EIS results [4]. The oxidation stability window of the SPE was measured using the linear sweep voltammetry technique, and the ion transfer number was determined using the Evans-Vincent-Bruce method [5].

Sodium Halide-Based Solid Electrolyte with High Ionic Conductivity

Sodium-ion batteries (SIBs) are considered one of the most prominent alternatives to lithium-ion batteries (LIBs) because of the abundance of sodium resources on Earth. However, compared to Li, Na has a heavier atomic weight (23 g mol–1 vs. 6.9 g mol–1) and higher standard potential, leading to lower volumetric and gravimetric energy density of SIBs than LIBs. The energy density of state-of-the-art room-temperature SIBs is in the range of 75 – 165 W h kg–1 or 250 – 375 W h L–1. To increase the energy density of SIBs, Na metal is proposed to be used as the anode material due to its superior theoretical specific capacity (1166 mA h g–1). To tackle the safety challenges brought by using Na metal, applying solid electrolytes (SEs) has been proposed to be an effective strategy. Despite the tremendous progress that has been made in the past decades, the progress and application are still in the infancy, experiencing numerous challenges for sodium solid-state batteries due to inherently low room-temperature ionic conductivity, interface complications, and fabrication.Inorganic halide-based SEs have emerged as a game changer because of their fast-conducting characteristics, adequate thermodynamic stability, great deformability, and good oxidative stability.1 Moreover, halide-based SEs are generally stable against moisture owing to their positive hydrolysis reaction energy. However, most of the studied halide-based SEs are based on the Li-ion system, with only a few based on the Na-ion system. Moreover, despite halide-based Na SEs theoretically having high ionic conductivity,2 experimental obtained samples have much lower ionic conductivities compared to their Li counterparts (usually < 0.1 mS cm–1). Therefore, developing halide-based SEs with high Na+ ionic conductivity is crucial for Na ASSBs. We recently identified a new Na halide-based SE with a room temperature Na+ ionic conductivity over 1 mS cm–1. The activation energy is also as low as 0.23 eV. Interestingly, the material shows a mixed amorphous and crystalline phase, and its ionic conductivity decreases with the increase of the crystalline phase. The ionic conductivity of > 1 mS cm–1 is already comparable to some organic liquid electrolytes and thus is sufficient for many practical applications. The developed strategy has the potential to be applied to other halide-based SEs to improve their ionic conductivity, promoting the development of SIBs.(1) Huang, J.; Wu, K.; Xu, G.; Wu, M.; Dou, S.; Wu, C. Recent Progress and Strategic Perspectives of Inorganic Solid Electrolytes: Fundamentals, Modifications, and Applications in Sodium Metal Batteries. Chem. Soc. Rev. 2023, 52 (15), 4933–4995.(2) Qie, Y.; Wang, S.; Fu, S.; Xie, H.; Sun, Q.; Jena, P. Yttrium–Sodium Halides as Promising Solid-State Electrolytes with High Ionic Conductivity and Stability for Na-Ion Batteries. J. Phys. Chem. Lett. 2020, 11 (9), 3376–3383.

PtCo nanoalloy embedded nitrogen-doped carbon nanotube for rechargeable Zn-air batteries

The large-scale application of metal-air batteries strongly depends on the development of cost-effective, highly efficient, and durable bifunctional oxygen catalysts. In this work, a facile approach for preparing the monodisperse PtCo nanoalloy anchored the nitrogen-doped carbon nanotubes (PtCo/NCNT) for zinc-air batteries is reported. The nitrogen-doped carbon shell prevents PtCo nanoalloy from exfoliation, dissolution, and aggregation and enables the accessibility of electrolytes to the alloy surface and the electron transfer. Besides, the strong interaction between PtCo nanoalloy and nitrogen-doped carbon can efficiently modulate the electronic structure of the formed active sites. When used as a cathode catalyst, the constructed rechargeable zinc-air battery presents higher power density (268 mW cm−2), specific capacity (840 mAh g−1), and excellent stability. More importantly, the PtCo/NCNT catalyst allows the all-solid-state cell to exhibit remarkable flexibility and high round-trip efficiency at various bending states, demonstrating a potential possibility to replace the conventional Pt/C and RuO2 catalysts.

Plasma-Enhanced Copper Sulfide/Oxide Electrode for Zinc-Air/Copper Dual Mode Battery

As search for novel electrochemical energy storage systems continues, metal-air batteries are one of the possible solution. Consisting of a metal anode and an air-breathing cathode, by design, they achieve much higher gravimetric energy density in theory. However, s-orbital metals suffer passivation issues and poses safety threats due to their reactivity with air and humidity. As a solution to this issue, safer d-block metals are being studied as an alternative. Zinc air batteries (ZABs) utilizes earth-abundant and cost-effective zinc as its anode, and has high theoretical capacity. At its cathode, oxygen evolution reaction (OER) and oxygen reduction reaction (ORR) occur during charging and discharge processes. Sluggish kinetics of ORR degrades the discharge performance, and is the bottleneck in commercial application of the zinc air battery. Additionally, irreversibility of the cathode reaction results in dissatisfactory retention of battery capacity. Current state-of-the-art noble metal catalysts achieves nearly 80% of the theoretical capacity. However, its cycling stability is severely limited to less than 200 cycles despite low discharge rate applied.Herein, we present a nitrogen plasma-enhanced copper sulfide/oxide catalyst (referred to as N-CuS) that exhibits good catalytic activity for its application as the air-breathing cathode for ZABs. The material is grown directly on metal foam surface using anodization, which is then treated using nitrogen plasma. Anodization creates defect-rich flakes of copper sulfide on the oxide surface, highly increasing surface area and creating the active sites. The material has good electrical conductivity and highly open porous structure that alleviates mass transport issues. Additionally, nitrogen plasma treatment further increases the surface area about 80%, and is expected to introduce nitrogen dopants to the surface, enhancing conductivity of the material. ECSA estimated by measuring Cdl shows that each process increases the ECSA by over 40 times and about 1.8 times, respectively.LSV of CuS and N-CuS half-cells have been performed to measure and compare catalytic performance of the material. N-CuS shows far higher current density and better catalytic activity (35mV less overpotential) than CuS, and higher output voltage is observed with N-CuS cells with the same current density. By assessing the GCPL (potential limited galvanostatic cycling) results, it was concluded that N-CuS requires lower charging voltage and exhibits higher discharge voltages than CuS.The overall performance was evaluated in a stack cell configuration, utilizing thin zinc foil as its anode to minimize mass error. The measured specific capacity of the cell was 789.3 mA·h·g-1, which approximately is 85% of the theoretical specific capacity of zinc-air cells (820 mA·h·g-1). This cell yields gravimetric energy density of about 666 Wh·kg-1. It is notable that these ZAB characteristics are comparable to Pt/C, the state-of-the-art catalyst as of now. N-CuS may be a viable replacement for the Pt/C electrode, resulting in the cost-saving effect. The cycling stability of both N-CuS and Pt/C-based ZAB has been assessed to show that N-CuS-based ZAB has much prolonged (more than twice the cycles) cyclability compared to Pt/C-based ZAB (Fig. S11).Additionally, ZAB constructed using N-CuS can operate in oxygen-deficient environments. As the counter reaction it utilizes redox reaction of copper oxides (Zn-Cu mode) in the substrate when operating in anaerobic conditions. The reduction of divalent and monovalent copper oxides appears as plateaus at 1.1 V and 0.8 V versus the zinc anode during GCPL. Due to this alternate reaction, the cell can operate even at low concentrations of oxygen or even in its absence.DFT calculations have been performed to elucidate the reaction mechanism and the intrinsic catalytic activity of the material, and shows nitrogen dopants improve reactivity of the active sites, thus reducing the overpotential.In summary, we have synthesized N-CuS as the OER/ORR catalyst for ZAB. Through anodization the catalyst was directly grown on the substrate and nitrogen plasma treatment further enhances the catalyst properties to render it higher surface area, conductivity, and better stability. This allows better reversibility in the OER/ORR and results in enhanced cyclability of the overall cell. The constructed RZAB exhibited high specific capacity of 789.3 mA·h·g-1, which, has higher capacity than the analogue using Pt/C catalyst. In addition, N-CuS based RZAB is capable of operating under oxygen-deficient conditions utilizing the metal oxide substrate. This allows the dual mode operation of zinc-air and zinc-copper modes, and results in a more consistent output from the RZAB, as short-term air supply issues could be buffered by this effect. Figure 1

Deep Learning Based 3D Resolution Recovery for Breakthrough Imaging of Electrochemical Energy Devices

Many energy materials can only be understood within the context of the (often sealed) devices they make up. Batteries and fuel cells contain intricate mixtures of materials with features and arrangements that span across many orders of magnitude in size and operate under non-ambient conditions. In these devices, the microstructures of the constituent materials and how they are arranged with respect to each other is directly linked to the device performance and degradation behaviors. Complicating matters, opening the devices for inspection and analysis can irreversibly alter the very microstructures in question and can pose safety hazards to researchers if not done correctly. Furthermore, critical material and device properties such as tortuosity or ion transport pathways can only be accurately quantified in 3D. As such, observing microstructures and their evolution in 3D and in their native state is essential for developing a robust understanding of how to engineer new battery and fuel cell materials and architectures with improved performance.X-ray microscopy (XRM) provides a unique method for observing these microstructures in 3D at high resolutions without needing to open them. However, microscopy techniques like XRM make tradeoffs between FOV and resolution, which can pose challenges for strongly multiscale systems like batteries and fuel cells. For example, if images are acquired at high enough resolution to observe critical features like electrode particle sizes in lithium-ion batteries or gas diffusion layer fiber weaves, catalyst distributions, and microporous layer cracks in polymer electrolyte fuel cells, the field of view of that image is restricted to a small local region of the sample. This means that broader defect distributions or larger scale inhomogeneities will be missed. Additionally, for quantitative analysis applications, this means that statistical relevance will be sacrificed because of the limited analysis volume at the appropriate resolution. And for computational modelling efforts, device level phenomena will not be captured well due to the restricted field of view.Advances in modern AI-based resolution recovery methods combined with the non-destructive multiscale imaging capabilities of X-ray microscopy have allowed researchers to overcome this dependency between resolution and field of view to produce 3D images with both high resolution and large field of view. We present here examples of applying these methods to applications in lithium-ion battery and polymer electrolyte fuel cell research [1].[1] Wang, Y.D., Meyer, Q., Tang, K. et al. Large-scale physically accurate modelling of real proton exchange membrane fuel cell with deep learning. Nat Commun 14, 745 (2023).

(Digital Presentation) Physical and Chemical Properties of Lithium Tetrachloroaluminate Monosolvate with Sulfur Dioxide

In connection with the expansion of the areas of application of lithium-ion batteries and the increase in their energy characteristics, researchers are increasingly paying attention to the problems of battery safety. The use of non-flammable electrolyte systems will significantly improve the safety of lithium-ion batteries.Electrolyte systems based on solvate complexes of sulfur dioxide have high electrical conductivity and are non-flammable [1]. The most studied composition is LiAlCl4 × 1.6 SO2 [1] and LiAlCl4 × 3 SO2 [2]. The properties of LiAlCl4 x SO2 monosolvate have not been described in the literature.The presented work summarizes the results of studies of the physicochemical properties (electrical conductivity, viscosity, density) of lithium tetrachloroaluminate monosolvate with sulfur dioxide (table). The temperature dependences of viscosity, density and electrical conductivity are presented in the figure.This work was performed as part of the Ministry of Science and Higher Education of the Russian Federation [Government Order Theme No. 121111900148-3]. References Hartl, R., Fleischmann, M., Gschwind, R., Winter, M., & Gores, H. (2013). A Liquid Inorganic Electrolyte Showing an Unusually High Lithium-Ion Transference Number: A Concentrated Solution of LiAlCl4 in Sulfur Dioxide. Energies, 6(9), 4448–4464. DOI:10.3390/en6094448Chul Wan Park, & Oh, S. M. (1997). Performances of Li/LixCoO2 cells in LiAlCl4 · 3SO2 electrolyte. Journal of Power Sources, 68(2), 338–343. DOI:10.1016/s0378-7753(97)02518-4 Figure 1

K3MnO4 a New Cathode Material for K-Ion Batteries

To meet future energy demands, developing beyond-lithium energy storage technologies have become a major part of global research activities. Potassium-ion batteries (KIBs) represent a promising technology thanks to their chemical and economic advantages1–3. To succeed in developing commercial KIBs, it is necessary to develop new cathode materials4 which must be non-toxic, inexpensive, easy to prepare and have a reasonable K+ diffusion pathway to improve their electrochemical performance. Here we have chosen to explore the inexpensive and non-toxic K-Mn-O system, where only two-dimensional materials of the KxMnO2 type have been studied so far for their electrochemical properties5,6.In this system, a composition attracted our attention: K3MnO4. In principle, up to two potassium ions can be removed from the structure, leading to KMnO4 with a theoretical capacity of 227 mAh/g.Hagenmuller and co-workers succeeded in preparing two polymorphs of K3MnO4 as single crystals7. The high temperature polymorph γ-K3MnO4 has a cubic symmetry (P213) with a disordered distribution of K and Mn in similar tetrahedral sites. The low temperature polymorph β-K3MnO4, can be prepared by annealing γ-K3MnO4 under argon. This polymorph has a tetragonal symmetry (I-42m) with ordered MnO4 tetrahedra. Mn is reported at the edge and at the center of the tetragonal unit cell, surrounded by four oxygens. These phases could be described as a 0D-type structure built of isolated MnO4 tetrahedra surround by potassium ions.We recently succeed in the synthesis of a new polymorph of K3MnO4, labelled α-K3MnO4,8 prepared by a conventional solid-state route by annealing a mixture of KO2 and MnO under vacuum at 500°C in a Al2O3 boat. The structure of this polymorph could be described with a “zig-zag” distribution of the MnO4 tetrahedra (Fig. 1a) and is isostructural to the iron-based K3FeO4 9,10 with an orthorhombic symmetry (Pnma). The blue colour of the powder is classically associated to the Mn+V oxidation state, as confirmed by magnetic and EDS analyses. K3MnO4 exhibits a reversible capacity of 70 mAh/g in the 1.6-3.5 V vs. K+/K potential window at C/20 (Fig. 1b).In our presentation, we will detail the electrochemical behaviour of K3MnO4 and discuss the structure/properties relationship of this family of materials, showing the interest in the exploration of such a system. Xu, Y. et al. 2023 roadmap for potassium-ion batteries. J. Phys. Energy 5, 021502 (2023).Tian, Y. et al. Promises and Challenges of Next-Generation “Beyond Li-ion” Batteries for Electric Vehicles and Grid Decarbonization. Chem. Rev. 121, 1623–1669 (2021).Zhang, W., Liu, Y. & Guo, Z. Approaching high-performance potassium-ion batteries via advanced design strategies and engineering. Sci. Adv. 5, eaav7412 (2019).Nathan, M. G. T. et al. Recent Advances in Layered Metal-Oxide Cathodes for Application in Potassium-Ion Batteries. Adv. Sci. n/a, 2105882.Liu, T. et al. Insight of K-deficient layered KxMnO2 cathode for potassium-ions batteries. J. Energy Chem. 64, 335–343 (2022).Liu, C., Luo, S., Huang, H., Zhai, Y. & Wang, Z. Layered potassium-deficient P2- and P3-type cathode materials KxMnO2 for K-ion batteries. Chem. Eng. J. 356, 53–59 (2019).Olazcuaga, R., Reau, J.-M., Leflem, G. & Hagenmuller, P. Préparation, Proprietés Cristallographiques et Magnétiques des Phases K3XO4 (X=V, Cr, Mn). Z. Für Anorg. Allg. Chem. 412, 271–280 (1975).Sagot, A., Stievano, L. & Pralong, V. K3MnO4: A New Cathode Material for K-Ion Batteries. ACS Appl. Energy Mater. 6, 7785–7789 (2023).Kokarovtseva, I. G., Belyaev, I. N. & Semenyakova, L. V. Oxygen Compounds of Iron(VI, V, IV). Russ. Chem. Rev. 41, 929–937 (1972).Hoppe, R. & Mader, K. Zur Konstitution von K3[FeO4]. Z. F ür Anorg. Allg. Chem. 586, 115–124 (1990). Figure 1

Re-Functionalization of Aged Lithium Iron Phosphate Cathode Materials

As lithium-ion batteries continue to be implemented in everyday technologies, it is imperative to repurpose these battery materials upon their degradation. Carbon-coated lithium iron phosphate (LFP/C) is considered one of the most stable cathode materials for application in lithium-ion batteries. Due to this stability, LFP/C possesses a remarkably long cycle life of greater than 3000 cycles.1 Extended cycling of these cathode materials may result in multiple modes of degradation, including degradation of the carbon coating, and loss of contact between the cathode and the current collector.2,3 In this work, a suitable process and reagents have been selected to isolate and purify the LFP/C from the cathodes of cycled batteries. Isolating and purifying aged LFP/C materials enables the diagnosis of the mode(s) of degradation of these materials and their coatings using a variety of techniques including X-ray diffraction, scanning electron microscopy, and transmission electron microscopy methods.Furthermore, additional work was pursued to give new life to these isolated, spent cathode materials. The addition of a coating with a relatively high lithium conductivity to the aged LFP/C particles was sought to provide a second life to these electrochemically aged materials. Half-cells were fabricated using the coated, aged LFP/C cathode materials to compare their performance to both pristine LFP/C nanoparticles and aged LFP/C nanoparticles without the addition of this custom coating. Electrochemical testing techniques such as galvanostatic cycling, cyclic voltammetry, and electrochemical impendence spectroscopy were used to probe the performance of each type of LFP/C nanoparticle as cathode materials in lithium-ion batteries. The coated, aged LFP/C particles were also characterized using transmission electron microscopy, energy dispersive spectroscopy, and X-ray photoelectron spectroscopy techniques. The techniques developed herein can be used to isolate, purify, and re-functionalize other cathode materials from lithium-ion batteries. Lewerenz, M.; Munnix, J.; Schmalstieg, J.; Kabitz, S.; Knips, M.; Sauer, D. U. Systematic aging of commercial LiFePO4|Graphite cylindrical cells including a theory explaining rise of capacity during aging. Power Sources. 2017, 345, 254-263.Wang, L.; Qiu, J.; Wang, X.; Chen, L.; Cao, G.; Wang, J.; Zhang, H.; He, X. Insights for understanding multiscale degradation of LiFePO4 cathodes. eScience 2022, 2(2), 125-137.

(Invited) Innovating Sustainable, Cost-Effective, and Durable Redox Flow Battery Membranes

In the quest to integrate renewable energy sources like solar and wind into the electric grid efficiently, the development of long-duration energy storage (LDES) systems is paramount. The U.S. Department of Energy's Long Duration Storage Shot initiative is at the forefront of this endeavor, aiming to reduce the costs of grid-scale energy storage by 90% for systems with over 10 hours of operation. A key player in this mission is the non-aqueous redox flow battery (RFB), known for its use of earth-abundant materials and potential to meet these cost-reduction goals. However, the commercial viability of RFBs hinges on the development of high-performance, cost-effective membranes, which are crucial for their functionality and affordability. These membranes' ionic conductivity is vital for the power density of RFBs, while their ion selectivity and solvent uptake greatly influence the batteries' cycle life.Our team has made groundbreaking advancements in membrane technology for non-aqueous flow batteries. We've addressed the challenge of balancing ionic conductivity with mechanical strength in polymer electrolytes. Our findings reveal that enhanced solvent uptake while boosting membrane ionic conductivity, can compromise mechanical integrity. To counter this, we've employed two strategies: selective plasticization of the ion-conductive block in block copolymers and reinforcing the membrane's mechanical strength through hydrogen and ionic bonds with an inorganic scaffold. Significantly, we've also reduced the crossover of redox-active species in our membrane designs, notably decreasing polysulfide species crossover in a Na metal – polysulfide hybrid flow battery. This has led to improved capacity retention, Coulombic efficiency, and extended cycle life compared to traditional porous membranes.Our latest innovations include the development of hydrocarbon single-ion conductors, demonstrating enhanced conductivity and stability. We've also introduced crosslinking chemistry to control solvent uptake more effectively, thus improving ionic conductivity while preserving mechanical strength. Lastly, our pioneering tape casting method for producing ceramic-polymer composite membranes represents a major leap in scalable membrane production, paving the way for the practical application of non-aqueous redox flow batteries in long-duration energy storage. Acknowledgment This research was conducted at Oak Ridge National Laboratory, managed by UT Battelle, LLC, for the U.S. Department of Energy (DOE) and is sponsored by the U.S. Department of Energy through the Energy Storage Program in the Office of Electricity. We acknowledge Dr. Jagjit Nanda SLAC National Accelerator Laboratory for the fruitful discussions.

(Invited) NiCo2O4/MnO2 Microsphere as Efficient Bi-functional Electrocatalyst for Zinc-air Battery

Microsphere-like NiCo2O4/MnO2 composite was synthesized via hydrothermal route as an efficient electrocatalyst with dual functionality, facilitating oxygen electrocatalysis reactions and serving as an air cathode in zinc-air batteries (ZABs) applications. The as-synthesized NiCo2O4/MnO2 demonstrated adaptable kinetics for both the oxygen reduction reaction (ORR) and oxygen evolution reaction (OER). Specifically, it displayed a half-wave potential of 0.692 V for ORR and an overpotential of 218 mV for OER at a current density of 10 mA·cm-2. The double layer capacitance for NiCo2O4/MnO2 was experimentally calculated to be 31.67 mF.cm-2, suggesting a substantial level of electrochemical activity in the synthesized composite. The ZAB device assembled with a NiCo2O4/MnO2 cathode in a 6 M KOH electrolyte achieved an open circuit voltage of 1.48 V. It demonstrated a maximum power density of 127.04 mW·cm–2 at a current density of 190.64 mA·cm-2 and exhibited a notable specific discharge capacity of 756.62 mAh·g-1 at a current density of 5 mA·cm-2. The ZAB exhibited remarkable stability over 200 hours (equivalent to 600 cycles) of charge-discharge cycling at 5 mA·cm-2, with an almost negligible decrease in voltaic efficiency (~1.58%). Moreover, the practical applicability of Zn//NiCo2O4/MnO2 battery was assessed by powering a 2 V light-emitting diode for 20 hours employing two ZAB devices connected in series. This study establishes a foundation for the feasible application of ZABs incorporating cathodes based on Ni-Co-Mn.

Reconstructing the Pseudo-2-Dimensional (p2D) Model in Comsol Multiphysics Using Mathematical Interfaces

The classic ‘pseudo-2-dimensional’ (p2D) model of Newman and co-workers (also known as the DFN model), with its different efficient implementations, is the state-of-the-art physics-based electrochemical model for lithium-ion batteries. COMSOL Multiphysics (COMSOL) is a popular modeling software for multiphysics simulations, and its Battery Design Module for Li-ion batteries is widely used in the battery modeling community. This work presents a step-wise model development for reconstructing the detailed p2D model equations. This includes variable model parameters and weak-form implementation for the solid-phase diffusion, eliminating the need for non-local couplings and approximations for modeling the pseudo radial-dimension in the solid-phase.To model and understand the effect of capacity degradation on lithium-ion cells, the battery models in COMSOL need to incorporate additional degradation mechanisms. In this work, we have followed the approach of equation-based modeling in COMSOL, which enables us to formulate the p2D model using the mathematical PDE interfaces. This approach provides us with a lot of flexibility in terms of battery degradation model formulation and helps develop a clearer understanding of the p2D model equation in light of the assumptions involved.The steps in the model development involved writing the conservation equations in the generic mathematics interfaces coupled with the additional equations for the degradation mechanisms. The efforts were centered on developing cycling simulations based on Events for practically relevant operating conditions. This custom model was validated against the results from COMSOL’s Battery Interface, in-house codes, and baseline cycle data from the experiments and further developed as a physicochemical degradation model for automotive, large-format Lithium-ion batteries.This equation-based COMSOL model with cycling works without the requirement for Battery Design Module, LiveLink and Application Builder and can be adopted for a variety of electrochemical modeling applications by the electrochemical modeling community.

Advancing Towards Commercialization with Enhanced Stability and Efficiency in Lithium Metal Batteries Using TTE as a Co-Solvent in Carbonate Electrolytes

Lithium metal batteries are considered ideal anode materials for next-generation battery systems due to their high theoretical specific capacity (3,860 mAh g-1) and low negative electrochemical potential (−3.040 V vs. the standard hydrogen electrode), which are essential for high energy density. However, the fatal dendritic growth on the lithium metal surface, which occurs during repetitive cycling, acts as a significant barrier to commercially successful lithium metal battery application. Therefore, regulating the morphology of lithium plating in commercial carbonate-based electrolytes is a critical challenge for the stable operation of lithium metal batteries. Additionally, this leads to the formation of inhomogeneous lithium dendrites in carbonate-based electrolytes, manifesting as uneven current density and lithium-ion concentration gradients. The uneven current leads to inconsistent charging/discharging rates in the corresponding Ni-rich cathode, which in turn causes overpotentials and deteriorates cell safety, culminating in a reduction of capacity. this has been clarified through Kelvin probe force microscopy analysis to demonstrate an uneven state of charge distribution in the Ni-rich cathode.In this work, we propose a new strategy for high-performance lithium metal batteries, utilizing 1,1,2,2-tetrafluoroethyl-2,2,3,3-tetrafluoropropyl ether (TTE) as a co-solvent with carbonate electrolytes. By using TTE as a co-solvent, we observed a reduction in the viscosity of the electrolyte, leading to improved ionic conductivity and a decrease in the overpotential during the lithium plating/stripping process via in-situ electrochemical atomic force microscopy. This resulted in more uniform Li deposition compared to conventional carbonate-based electrolytes, forming a dense and stable Li metal layer. Furthermore, by leveraging our control over stable lithium plating morphologies via TTE co-solvent system, we observed long-term cycling stability (capacity retention of 78% at 300 cycles) with the use of an ultra-thin Li layer (40 µm). Through these results, we have effectively enhanced the stability and efficiency of high-energy-density (380 Wh kg-1) electrodes based on carbonate electrolytes, and we believe that this study can contribute to the commercialization of lithium metal batteries. Figure 1

Stable Lithium Metal Batteries Enabled by Dilute Cationic Additives

Conventional Li-ion electrolytes consist of carbonate solvents and Li-ion salts that were made for carbonaceous negative electrodes. When the electrolytes are used with metallic lithium anodes, carbonate electrolytes lead to low charge-discharge cycle stability due to adverse reactive species at the anode surface.1-4 This reactive species are called the solid electrolyte interface (SEI).1 SEI instabilities/inhomogeneities result in its continuous thickening and formation of electronically non-active dead lithium.2 SEI composition and structure are affected by both solvent and electrolyte chemistry in bulk solution and, more importantly, at the electrode-electrolyte interface.4 Current research studies suggest that X-rich (where X is a halogen) SEI yields superior performance compared to halogen-free SEI.1,5 Electrolytes that have large volume fractions of halogenated species have statistically higher probability to be reduced at the electrode surface and yield X-rich SEI layers.6 Therefore, the use of halogenated solvent and/or high concentrated (> 1 M) lithium salt with halogenated anions has been actively explored for LiMBs. However, the high cost of Li salts and high viscosity of the electrolyte at high salt concentration make the concentrated electrolytes unrealistic for commercial battery applications. In search of a cost-effective solution for high performance LiMBs, halogenated electrolyte additives could serve as an ideal approach since only a small amount of the additive would be potentially required to induce similar X-rich interface that can be seen in the case of the halogenated ether electrolyte. In this meeting abstract, we present a new concept that leverages favorable electrostatic interactions with the electrolyte additive to drive the formation of robust SEI layers even at low additive content. Specifically, custom-designed additives can be electrostatically attracted to the negatively charged electrode, creating a high population of halogenated species at the anode surface even at a dilute Li salt concentration. Effective SEI formation with a low-concentration additive circumvents the challenges associated with the current state-of-the-art approach of using halogenated species at high concentration (i.e., unfavorably high solution viscosity and high cost). Reference 1 Louli, A. J. et al. Diagnosing and correcting anode-free cell failure via electrolyte and morphological analysis. Nature Energy 5, 693-702, (2020).2 Chen, K.-H. et al. Dead lithium: mass transport effects on voltage, capacity, and failure of lithium metal anodes. Journal of Materials Chemistry A 5, 11671-11681, (2017).3 Lin, D. et al. Three-dimensional stable lithium metal anode with nanoscale lithium islands embedded in ionically conductive solid matrix. Proc Natl Acad Sci U S A 114, 4613-4618, (2017).4 Lin, D., Liu, Y. & Cui, Y. Reviving the lithium metal anode for high-energy batteries. Nat Nanotechnol 12, 194-206, (2017).5 Yu, Z. et al. Molecular design for electrolyte solvents enabling energy-dense and long-cycling lithium metal batteries. Nature Energy 5, 526-533, (2020).6 Yamada, Y., Wang, J., Ko, S., Watanabe, E. & Yamada, A. Advances and issues in developing salt-concentrated battery electrolytes. Nature Energy 4, 269-280, (2019).

Regulating the Electrochemical Performance of Simple Halogen-Free Electrolyte Using Ammonium Bromide Additive for Magnesium-Sulfur Battery Applications

Magnesium-sulfur (Mg-S) batteries are a promising energy storage system; however, the short cycle life, low coulombic efficiency, and the shuttle effect of polysulfide hinder its practical application. Applying electrolyte additives is a powerful technique to optimize the electrochemical performance of Mg-S electrolytes. Herein, ammonium bromide (NH4Br) is used as an inorganic electrolyte additive in the halogen-free electrolyte (HFE) to guide homogeneous Mg deposition. It can be noticed that the addition of NH4Br decreases the activation energy values from 0.14 eV to 0.10 eV and reduces the value of Mg2+ stripping/plating overpotential. It is found that the introduction of NH4Br to HFE enhances the cycle life and the initial discharge capacity (~1662 mAhg-1) of the Mg-S cells compared with the cells using free NH4Br that deliver initial discharge capacity of ~ 184 mAh g-1, low coulombic efficiency, and short cycle life. Further efforts have been devoted by implementing a BaTiO3 (BTO) as a modified separator to overcome the polysulfide dissolution issue in the cell. The surface of the cell's anode applying a modified separator shows half wt.% S content compared with the bare cell after cycling. This study opens further research for developing novel electrolyte schemes for magnesium-sulfur battery applications.

Recycling Process of Spent Alkaline and Zn-C Batteries for the Re-Utilization in Rechargeable Zn-Ion Battery

The Zn, Mn and C extraction processes from spent primary batteries and the synthesis of recycled Zn film, MnO2 and MnO2/C for Zn-ion battery application were developed in the project. The Zn, Mn and C extraction process involved the acid leaching of Zn and Mn ions from the spent alkaline and Zn-C battery electrodes in the lab-scale was initially investigated using various leaching conditions. The acid leaching using 0.5-2 M HCl and H2SO4 at ambient temperature providing Zn extraction efficiencies in a range of 72.3-95.3%. By introducing an inexpensive reducing agent namely sodium sulfide (Na2S), sodium metabisulfite (Na2S2O5) or hydrogen peroxide (H2O2) in 2M H2SO4, the Mn extraction efficiency for Mn was increased from 21.9% (with no reducing agent) up to 48.4%, 82.8% and 98.9%, respectively. The upscale leaching study was subsequently performed in a 100-L pilot scale reactor demonstrated the Zn and Mn extraction efficiencies of 71% and 65%, respectively. Using the leaching solutions from the upscale hydrometallurgical route, Zn-film fabrication via electrodeposition process, and the MnO2 and MnO2/C synthesis via hydrothermal techniques were performed. Additionally, the one-step synthesis of MnO2/C via one-step hydrothermal method with no acid leaching was also explored in this study. The recycled Zn, MnO2, MnO2/C and C residual were subsequently used as the anode and cathode main components in the CR2032 and pouch-cell rechargeable Zn-ion batteries. The recycled MnO2 and MnO2/C provided similar performance as the commercial products, which indicating the recycled MnO2, MnO2/C could be effectively utilized in the Zn-ion battery, while the utilization of recycled Zn-film provided slightly lower performance compared to that of the commercial Zn foil.

Solving ZIB Challenges: The Dynamic Role of Water in Deep Eutectic Solvents Electrolyte

Zinc-Ion batteries (ZIBs) are considered one of the most promising technologies in the realm of post-lithium-ion batteries. Rechargeable chemistries with zinc anodes hold significant technological potential due to their high theoretical energy density, lower manufacturing costs, abundant raw materials, and inherent safety. ZIBs typically feature neutral or weakly acidic aqueous electrolytes and exhibit typical drawbacks of Zn anodes: hydrogen evolution, passivation, and shape changes.In aqueous electrolytes, two types of water molecules can be described: free water molecules and solvated water molecules that participate in Zn2+ solvation structure [Zn(H2O)6]2+. The free water easily reacts with metallic Zn at the electrode/electrolyte interface, leading to the aforementioned irreversibilities. Alternative electrolytes such as Deep Eutectic Solvents (DESs) can be used to modulate Zn solvation shell, preserving the green and safe characteristics of aqueous-based ones. DESs show relevant characteristics for battery applications, such as low vapor pressure, good thermal and chemical stability, non-flammability, easy moldability, wide electrochemical window, and structured interface. However, a main drawback for electrochemical applications is the high viscosity, low diffusivity, and sluggish kinetics.Water molecules can be added as a cosolvent to eutectic mixtures to increase the diffusion coefficient of electroactive species and reduce the electrolyte viscosity without destroying the eutectic nature by up to 40%. The hydration percentage of DES can modify the thickness of the electrolyte-electrode interface and the Zn2+ solvation structure. Thus, the tuning capability, on one hand, of the solution chemistry of Zn2+ containing electroactive species, and on the other hand, of the electrode–electrolyte interfacial structure and chemistry by the combined use of DES and water provides a flexible tool to control Zn plating and stripping processes.In this study, we investigate the electrochemistry of Zn in ethaline DES with different percentages of water (0%, 5%, 10%, 25%, 50%, 70%, respectively), transitioning from a water-in-salt structure to a salt-in-water one. Fundamental electrokinetic and electrocrystallization studies based on cyclic voltammetry and chronoamperometry at different cathodic substrates were complemented with galvanostatic cycling tests of Zn|Zn symmetric CR2032 coin cells, SEM imaging of electrodes, and in situ Surface Enhanced Raman spectroscopy (SERS).Moreover, the Zn solvation structure was investigated using spontaneous Raman spectroscopy . The employed methodology provided valuable insights into the Zn plating reaction. Water molecules are present in a "confined" state rather than a free one, directly interacting with choline cations and being trapped in the eutectic framework if the molar fraction is kept below 40%.When ZnSO4 is dissolved in anhydrous ethaline, the [ZnCl4]2− species is formed and stabilized by choline. The peculiarities of Zn2+ coordination were found to result in unusual voltammetric behavior, characterized by a cathodic peak in the cathodic branch of the anodic-going scan.Although tetrachlorozincate is the dominant species, it does not seem to be the complex from which Zn is deposited; indeed, [ZnCl4]2− has a very negative reduction potential. Mechanistic studies of Zn electrodeposition onto different cathodic materials have concluded that the metal is formed by the reduction of an intermediate Zn-containing species. The two organic components of the eutectic solvents can be dehydrogenated at a negative potential, forming RO-, which can replace one or more chloride ligands in [ZnCl4]2−.Hydrated DES exhibits faster kinetics, which, in turn, leads to a lower nucleation overpotential. This phenomenon has been explained with two different mechanisms occurring at the same time. Firstly, by increasing the hydration percentage in the eutectic framework, the coordination of Zn2+ changes, forming [ZnCl3(H2O)]-. The water molecule in the Zn2+ sheath has a lower energy barrier than chlorine in the step-by-step desolvation of Zn2+. Consequently, the [ZnCl3(H2O)]- complex exhibits a lower dissociation energy than [ZnCl4]2- present in anhydrous ethaline, resulting in a faster desolvation process that can reduce nucleation overpotentials.Secondly, water molecules hydrogen-bonded to DES components can be reduced at cathodic potential, forming H· radicals that can then participate in the decomposition of the organic component. This apparent side reaction can aid in the formation of RO- ligands that participate in the Zn-species undergoing reduction, thereby increasing the amount of reactants.This multi-technique approach, also applicable to the study of new electrolytes, leads to the optimization of DES hydration, reducing the presence of free water and addressing the main drawbacks associated with eutectic electrolytes. The nuanced understanding of the interplay between solvent composition, Zn solvation, and electrodeposition mechanisms paves the way for the development of more efficient and sustainable ZIB technologies. Figure 1

Using Three-Dimensional Carbon and Boron Nitride to Improve the Properties of Polyethylene Oxide-Based Solid-State Electrolytes for Li Ion Batteries

Polyethylene oxide (PEO)-based solid-state electrolyte (SSE) is attractive due to its excellent adhesion with electrodes and good processability. However, lithium dendrites easily penetrate PEO because of their soft nature, which results in inferior battery performance and safety issues. In this talk, we will discuss the development of 3D (insulating) amorphous carbon and 3D amorphous BN to improve the properties of polyethylene oxide (PEO)-based solid-state electrolytes for Li ion batteries.For the 3D amorphous carbon, we developed a novel self-healing PEO-based SSE is prepared by incorporating 2 wt% amorphous three-dimensional carbon (3DC). This SSE possesses suitably low electronic conductivity for battery applications (on the order of 10^−9 S/cm), which is five orders of magnitude lower than its ionic conductivity (10−4 S/cm) at 60 °C. In addition, the improved fluidity and strong adhesion between the 3DC and the PEO matrix contribute to the self-healing ability of SSE, which will repair the cracks of SSE formed during battery cycling. Moreover, this SSE shows enhanced ionic and thermal conductivities and mechanical strength, suppressing the formation and growth of lithium dendrites. As a result, this SSE exhibits excellent electrochemical stability, achieving 5000 h of stable cycles in lithium symmetric cell (0.1 mA cm−2, 0.1 mAh cm−2) and 850 long-term stable cycles for the LFP//Li full cell at 1 C (0.31 mA cm−2).For the 3D amorphous BN, we have developed the first synthesis of powdery hexagonal boron nitride (h-BN). This synthesis introduces a novel NaCl-glucose assisted strategy to synthesize micron-sized 3D h-BN with a honeycomb-like structure. When incorporated into polyethylene oxide-based electrolytes for Li-ion batteries, 5 wt% of 3D h-BN significantly enhances ionic conductivity and mechanical strength. Consequently, this composite electrolyte demonstrates superior electrochemical stability; it delivers 300 h of stable cycles in the lithium symmetric cell at 0.1 mA cm-2 and retains 89 % of discharge capacity (138.9 mAh/g) after 100 cycles at 1 C in the LFP//Li full cell.These two approaches reveal that 3DC and 3D h-BN can be used to improve the properties of PEO-based electrolytes of Li-ion batteries.

Enhanced Discharge Capacity in Carbon Felt Electrodes for Aqueous Aluminium-Ion Half-Cells

Diversifying the battery technology in use is an important step in ensuring a sustainable transition to a carbon neutral society, and reducing the emissions associated with lithium-ion cell manufacture. Aluminium is an attractive material for battery applications due to its high theoretical volumetric charge storage capacity of 8046 mA h cm−3 compared to lithium’s 2061 mAh cm-3 and relative abundance in the earth’s crust (1). Aqueous Al-ion batteries are one of many metal-ion systems being investigated utilising water as the electrolyte (2). Further, there are well-established mining, processing, and recycling routes for aluminium, with Li-ion battery recycling still in its infancy (3). Using aqueous electrolytes further provides improved safety as fire risk is reduced, and manufacturing costs are also reduced (4).The substrate on which the electrode material is applied impacts how it is utilised within an electrochemical system. The substrate provides both a shape to the electrode, as well as the material itself forming part of the system, and common substrates double as current collectors e.g. thin metal foils, but carbon polymers have also been explored as a substrate (5, 6). Carbon felt is a conductive substrate, with thin fibres of 5-10 μm diameter, providing a flexible porous structure and large surface area for the active material ‘ ink’ to adhere (0.4 m2 g-1 (7)) . Carbon based electrodes have been assessed in a non-aqueous Al-ion cathodes (8), with varying performance metrics based on the structure and make-up of the electrode, however, these were not investigated as a substrate for further electrode ink. In adding the ink to the carbon felt, the electrode becomes an effective 3D-matrix electrode.This poster explores the use of such 3D-matrix electrodes in order to increase the amount of active material utilised within the aq. Al-ion battery system (9) – a key requirement in reducing the environmental impacts of the battery overall (5), and a means for increasing the capacity of an individual electrode without increasing the overall volume. The cell described in (10) has a carbon-polymer electrode substrate, anatase TiO2 negative electrode and a copper hexacyanoferrate (CuHCF) positive electrode, with the electrolyte being 1 M AlCl3 + 1 M KCl. While the CuHCF redox reaction is partially understood, the negative electrode mechanism has not been fully elucidated. A theorised surface reaction, and pseudo-capacitance of the TiO2 electrode in the aq. Al-ion battery would benefit from an increased surface area of the electrode provided by the carbon felt. Therefore, a key factor in achieving the optimum utilisation of active material is not purely an increase of TiO2 in the electrode, but an increase in the surface area in contact with the electrolyte. Key findings presented show that the lower active material loadings result in a higher discharge capacity for both the positive and negative electrodes, with values reaching an order of magnitude higher than seen for the 2D electrodes studied in the past. For the TiO2 electrode, we see 205.0 mAh g-1 @978 mA g-1 (1.81 mg cm-2 active material loading) and for the CuHCF, 259 mA h g-1 @ 1256.8 mA g-1 (2.5 mg cm-2 active material loading). Elia GA, Kravchyk KV, Kovalenko MV, Chacón J, Holland A, Wills RGA. An overview and prospective on Al and Al-ion battery technologies. Journal of Power Sources. 2021;481:228870. Wu D, Li X, Liu X, Yi J, Acevedo-Peña P, Reguera E, et al. 2022 Roadmap on aqueous batteries. Journal of Physics: Energy. 2022;4(4):041501. Baum ZJ, Bird RE, Yu X, Ma J. Lithium-ion battery recycling─ overview of techniques and trends. ACS Publications; 2022. Chao D, Zhou W, Xie F, Ye C, Li H, Jaroniec M, et al. Roadmap for advanced aqueous batteries: From design of materials to applications. Science Advances. 2020;6:eaba4098. Melzack N. Advancing battery design based on environmental impacts using an aqueous Al-ion cell as a case study. Scientific Reports. 2022;12(1):8911. Holland A, Kimpton H, Cruden A, Wills R. CuHCF as an electrode material in an aqueous dual-ion Al3+/K+ ion battery. Energy Procedia. 2018 d;151:69-73. Sigracell. Speciality Graphites for Energy Storage. 2016. McKerracher RD, Holland A, Cruden A, Wills RGA. Comparison of carbon materials as cathodes for the aluminium-ion battery. Carbon. 2019;144:333-41. Holland A, McKerracher RD, Cruden A, Wills RGA. An aluminium battery operating with an aqueous electrolyte. Journal of Applied Electrochemistry. 2018;48(3):243-50. Melzack N, Wills R, Cruden A. Cleaner Energy Storage: Cradle-to-Gate Life Cycle Assessment of Aluminum-Ion Batteries With an Aqueous Electrolyte. Frontiers in Energy Research. 2021;9(290).