Double-Layered Perovskite Oxyfluoride Cathodes with High Capacity Involving O-O Bond Formation for Fluoride-Ion Batteries.

Developing electrochemical high-energy storage systems is of crucial importance toward a green and sustainable energy supply. A promising candidate is fluoride-ion batteries (FIBs), which can deliver a much higher volumetric energy density than lithium-ion batteries. However, typical metal fluoride cathodes with conversion-type reactions cause a low-rate capability.

Interfacial Stability of Phosphate-NASICON Solid Electrolytes in Ni-Rich NCM Cathode-Based Solid-State Batteries.

A nondegrading, low-impedance interface between a solid electrolyte and cathode active materials remains a key challenge for the development of functional all-solid-state batteries (ASSBs). The widely employed thiophosphate-based solid electrolytes are not stable toward oxidation and suffer from growing interface resistance and thus rapid fading of capacity in a solid-state battery. In contrast, NASICON-type phosphates such as LiAl Ti(PO) and LiAl Ge(PO) are stable at high potentials, but their mechanical rigidity and high grain boundary resistance are thought to impede their application in bulk-type solid-state batteries.