PVDF-based electrolyte decorated by Li29Zr9Nb3O40 Li-ion conductor and electrochemical performance of related solid-state batteries

Solid-state Li-ion batteries (LIBs) have recently attracted much attention for their high safety and energy density . Polyvinylidene fluoride (PVDF) is as a potential electrolyte for solid-state LIBs due to its high permittivity, wide voltage window and excellent thermal stability. Here, Y 3+ -doped Li 29 Zr 9 Nb 3 O 40 (LZNO) Li-ionic conductor with room temperature conductivity (σ 25 ) of 1.26 × 10 −4  S cm −1 is prepared. LZNO decorated PVDF-based composite solid electrolytes (CSEs) are fabricated. The PVDF-based CSE with 10% (mass ratio) of LZNO shows σ 25 of 2.34 × 10 −4  S cm −1 , and has thermal stability with melting temperature up to 332 °C and voltage window of 4.8 V. The assembled Li ( Ni 0.8 Co 0.1 Mn 0.1 ) O 2 |CSE|Li cells show initial specific discharge capacity of 216.7 mAh g −1 at 0.1 C, and exhibit high capacity and cycle performance. LiFePO 4 |CSE|Li cells display initial specific discharge capacity of 137.4 mAh g −1 at 0.5 C and high cycle performance. Addition of LZNO powder in CSEs can inhibit the dehydrofluorination of PVDF during the charge-discharge of cells, alleviate the deterioration of interface resistance, and greatly improve the specific discharge capacity of cells at high rates.