Enhanced ionic conductivity of a Na3Zr2Si2PO12 solid electrolyte with Na2SiO3 obtained by liquid phase sintering for solid-state Na+ batteries

-added NZSP solid electrolyte exhibits a remarkably extended cycling capacity of 96.6% capacity retention after being cycled at 0.1 C 100 times. The liquid phase sintering with addition of low melting point salt compounds to electrolyte powder represents a rapid and straightforward technique for improving other ceramic electrolytes.