Aqueous rechargeable batteries are promising candidates for large-scale energy storage owing to their inherent safety, low cost, and environmental compatibility, yet the narrow 1.23 V electrochemical stability window (ESW) of water limits their energy density. Since the seminal 2015 report of water-in-salt electrolytes...
Na4Fe3(PO4)2P2O7 (NFPP), an iron-based mixed phosphate–pyrophosphate cathode material, has emerged as one of the most commercially promising candidates for large-scale sodium-ion battery (SIB) energy storage applications. Its exceptional characteristics—an ultralow volume change of less than 4% during Na+ de/intercalat...
Alluaudite‐type Na
2+2x
Fe
2−
x
(SO
4
)
3
(NFS) has attracted considerable attention as a promising cathode for sodium‐ion batteries (SIBs), owing to its cost‐effective composition and relatively high operating voltage. Nevertheless, the further practical use of NFS is still hindered by its intrinsical...