Solid-State Sodium-Ion Batteries: Theories, Challenges and Perspectives.

Sodium-ion batteries have abundant sources of raw materials, uniform geographical distribution, and low cost, and it is considered an important substitute for lithium-ion batteries. Thereinto, solid-state sodium-ion batteries have the advantages of low raw material cost, high safety, and high energy density, and it has shown great potential for application in the fields of mobile power, electric vehicles, and large-scale energy storage systems. However, the commercial development and large-scale application of solid-state sodium-ion batteries urgently need to address issues such as the low room-temperature ionic conductivity of solid electrolytes, high interfacial charge transfer impedance, and poor compatibility and contact between the solid electrolytes and the electrodes.