Advancing High-Energy Solid-State Batteries with High-Entropy NASICON-type Solid Electrolytes

Abstract

with a total (grain + grain-boundary) ionic conductivity of ∼1.42 × 10 −4 S cm −1 (highest reported among NASICONs containing Zr−Sn−Ti) and a low activation energy of ∼0.33 eV with a relative density of Conventionally Sintered pellet ∼94%. Symmetric cells with a PVDF-HFP/LiTFSI buffer layer showed stable performance for 500 cycles at 0.2 mA cm −2 without short-circuiting. Full cells with LiFePO 4 retained ∼99% capacity after 100 cycles at 1C, while those with NMC811 delivered ∼140 mAh g −1 at C/ 3.