A fluorophosphate glass–ceramic electrolyte with superior ionic conductivity and stability for Na-ion batteries†
All solid-state sodium-ion electrolytes have attracted increasing attention due to their wide range of applications in secondary batteries. Here, a new fluorophosphate glass–ceramic electrolyte, (Na2O + NaF)–TiO2–B2O3–P2O5–ZrF4 (NTBPZ), has been proposed and synthesized. Due to a low activation energy of 13.9 kJ mol−1 and reduced resistance at the grain boundaries, the NTBPZ glass ceramic has a room-temperature ionic conductivity as high as 3 × 10−5 S cm−1. In addition, the NTBPZ electrolyte has excellent thermal and chemical stabilities under ambient conditions. These outstanding performances make the NTBPZ a promising electrolyte for all-solid-state sodium-ion batteries.