Advanced metal–organic frameworks for aqueous sodium-ion rechargeable batteries

Inexpensive and abundant sodium resources make energy storage systems using sodium chemistry promising replacements for typical lithium-ion rechargeable batteries (LIBs). Fortuitously, aqueous sodium-ion rechargeable batteries (ASIBs), which operate in aqueous electrolytes, are cheaper, safer, and more ionically conductive than batteries that operate in conventional organic electrolytes; furthermore, they are suitable for grid-scale energy storage applications. As electrode materials for storing Na⁺ ions in ASIBs, a variety of multifunctional metal–organic frameworks (MOFs) have demonstrated great potential in terms of having porous 3D crystal structures, compatibility with aqueous solutions, long cycle lives (≥1000 cycles), and ease of synthesis. The present review describes MOF-derived technologies for the successful application of MOFs to ASIBs and suggests future challenges in this area of research based on the current understanding.