Hydrogen is a clean, flexible, powerful energy vector that can be leveraged as a promising alternative to fossil fuels. Additionally, green hydrogen production has been recognized as one of the most prevalent solutions to decarbonize the energy system. Water electrolysis studies have increased throughout the decade as higher industrial interest comes into play. The catalyst, system design, and configuration act in a congenial manner to deliver high‐performing water electrolysis. Despite performance targets peaking at high current densities, the current status of water electrolyzer technologies would require more research efforts to achieve such goals. This work presents a comprehensive review of how catalysts and electrolyzer designs can be enhanced to attain high current density water electrolysis. Modification strategies of catalysts, advances in characterization and modelling, and optimizing system designs are highlighted. Furthermore, this paper aims to elucidate the future research direction of water electrolysis to bridge the laboratory‐to‐industry gap.

With the rising energy demand, safe and efficient energy storage technologies have been increasing in importance. Lithium-ion batteries (LIBs) have been dynamically prevalent as energy storage and power sources for various electrical systems, from communication purposes to transportation applications. Lithium Polymer (LiPo) batteries are a subcategory of LIBs that use a solid or semisolid (gel) polymer to act as both a separator and electrolyte for the system. Compared to a conventional liquid electrolyte, gel polymer electrolyte is more thermally and electrochemically stable and relatively safer. Various companies produce a vast number of different LiPo batteries; however, a limited number of studies have been conducted concerning modeling and simulation. Besides exploring new materials for performance enhancement, engineering a reliable model is equally vital to exploit and optimize existing LiPo batteries' potential. In this study, a multiphysics model for a mobile Lithium Cobalt Oxide (LCO)-graphite- Poly(vinylidene fluoride - hexafluoropropylene) (PVdF-HFP) pouch LiPo battery was established to characterize the battery's behavior. The pseudo-2-dimensional electrochemical model and 3D thermal-thermal runaway model were coupled with temperature and heat generation variables. Working voltage and temperature during galvanostatic discharge were examined for the electrochemical-thermal model. In contrast, temperature as a function of time during an oven test was analyzed for thermal runaway models. The electrochemical-thermal and thermal runaway behavior was investigated using the simulation model, and validations were compared with experimental data. Overall, the models can be employed as a design tool to evaluate the component design and estimate the system performance of LiPo batteries for commercial applications. KEYWORDS: Multiphysics model, Lithium-polymer battery, Thermal runaway

Lithium-ion batteries (LIBs) have circumvented the energy storage landscape for decades. However, safety concerns about liquid–electrolyte-based LIBs have challenged their mobilization. Lithium polymer (LiPo) batteries have gained rising interest due to their high thermal stability. Despite an array of commercially available LiPo batteries, limited studies have ventured into modeling. Numerical simulations allow low-cost optimization of existing battery designs through parameter analysis and material configuration, leading to safer and more energy-efficient batteries. This work examined the electrochemical, thermal, and thermal runaway behavior of a lithium cobalt oxide cathode, graphite anode, and poly(vinylidene fluoride-hexafluoropropylene) electrolyte pouch-type LiPo battery using COMSOL Multiphysics®, and validated results with experimental data. The simulated potential curve exhibited strong agreement with experiment data, while the temperature profile during discharge displayed qualitative discrepancies rationalized by the reversible heat generation. Thermal runaway simulations via oven tests revealed that the highest heat generation is from the cathode–electrolyte reaction, while the solid electrolyte interface decomposition initiates the heat generation process. These results suggest a thorough selection of cathode and electrolyte material to heighten battery safety. Overall, the developed models can be utilized as design tools to investigate various chemistries and designs to estimate the behavior and performance of batteries.