Partially Etched Ti3C2Tx MXene with Residual Aluminium Boosts Ionic Conduction in PVDF-Based Composite Solid Polymer Electrolytes

Abstract

Low tLi⁺ and conductivity in poly (vinylidene fluoride) (PVDF) composite solid polymer electrolytes (CSPEs) are mitigated by TTAC: residual Al2O3 and Al vacancies enhance LiTFSI dissociation; surface -F/-O groups displace PVDF from Li⁺ coordination, lowering desolvation barrier; reduced crystallinity expands amorphous regions for faster Li⁺ transport. Li||Li cells function for 2500 hours without dendrites, yielding 4.21 × 10-3 S/cm at 30 °C and tLi⁺ = 0.82. After 800 cycles at 0.5 C, Li||LiFePO4 provides 140.5 mAh/g with 94.2% retention and 99.9% Coulombic efficiency.