Electrochemical energy storage and conversion: An overview

Electrochemical energy storage and conversion devices are very unique and important for providing solutions to clean, smart, and green energy sectors particularly for stationary and automobile applications. They are broadly classified and overviewed with a special emphasis on rechargeable batteries (Li‐ion, Li‐oxygen, Li‐sulfur, Na‐ion, and redox flow batteries), electrocatalysts, and membrane electrolytes for fuel cells. The critical challenges for the development of sustainable energy storage systems are the intrinsically limited energy density, poor rate capability, cost, safety, and durability. Albeit huge advancements have been made to address these challenges, it is still long way to reach the energy demand, especially in the large‐scale storage and e‐mobility. A landscape of battery materials developments including the next generation battery technology is meticulously arrived, which enables to explore the alternate energy storage technology. Next generation energy storage systems such as Li‐oxygen, Li‐sulfur, and Na‐ion chemistries can be the potential option for outperforming the state‐of‐art Li‐ion batteries. Also, redox flow batteries, which are generally recognized as a possible alternative for large‐scale storage electricity, have the unique virtue of decoupling power and energy. In this overview, a systematic survey on the materials challenges and a comprehensive understanding of the structure–property–performance relationship of the storage and conversion devices is covered. Further, in‐depth detailing of various catalysts and membrane electrolytes that can be explored as a viable alternative for polymer electrolyte fuel cells as well as direction toward futuristic research areas is highlighted.