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, Y3+-doped Li29Zr9Nb3O40 (LZNO) Li-ionic conductor with room temperature conductivity (025) of 1.26 x 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 025 of 2.34 x 10-4 S cm -1, and has thermal stability with melting temperature up to 332 degrees C and voltage window of 4.8 V. The assembled Li(Ni0.8Co0.1Mn0.1)O2|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. LiFePO4|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 resis-tance, and greatly improve the specific discharge capacity of cells at high rates.

Automated summary

Solid-state Li-ion batteries have gained significant attention for their high safety and energy density. Polyvinylidene fluoride (PVDF) has shown potential as an electrolyte due to its high permittivity, wide voltage window, and excellent thermal stability. This study successfully prepared Y3+-doped Li29Zr9Nb3O40 (LZNO) Li-ionic conductor and fabricated LZNO-decorated PVDF-based composite solid electrolytes. Addition of LZNO powder improved the interface resistance and greatly enhanced the specific discharge capacity of the cells at high rates.