Enabling high-capacity Li metal battery with PVDF sandwiched type polymer electrolyte

Polyvinylidene difluoride (PVDF) is one of the most attractive electrolyte materials for solid-state batteries due to its high ionic conductivity, however, the battery performance is limited by the high electrolyte- electrode interfacial resistance. Herein, PVDF polymer mixed with ceramic Li7La3Zr2O12 is coated on cellulose support membrane (PLCSM) through a simple slurry-casting method. The ionic transport of PLCSM is originated from dimethyl formamide (DMF)-Li+ solvation structure, which plays a critical role in conducting lithium ions. b-PVDF after dehydrofluorination offers a high dielectric constant and enhances the dissociation of lithium salt. As a result, PLCSM with a total thickness of 85 lm presents an oxidation voltage of 4.9 V. Li-Li symmetric cells by employing PLCSM reveal that the critical current density (CCD) is increased to 1 mA cm-2. A full cell of LiFePO4 |PLCSM |Li with high mass loading (1.2 mA h cm-2) shows a first-cycle discharge capacity of 160 mA h g-1. With LiNi0.6Mn0.2Co0.2O2 as the cathode, the initial discharge capacity is 153 mA h g-1, and the capacity retention after 80 cycles is 80%. The sandwiched PLCSM provides an effective strategy to achieve high-performance dendrite-free Li metal batteries. CO 2022 Published by Elsevier Inc.

Automated summary

Polyvinylidene difluoride (PVDF) is a promising electrolyte material for solid-state batteries, but its performance is limited by the resistance at the electrolyte-electrode interface. Researchers have developed a PVDF and ceramic Li7La3Zr2O12 mixture coated on a cellulose support membrane, improving the electrolyte's performance. This PVDF-ceramic mixture shows potential for achieving high-performance dendrite-free Li metal batteries.