Electrochemical Performance of a PVDF-HFP-LiClO4-Li6.4La3.0Zr1.4Ta0.6O12 Composite Solid Electrolyte at Different Temperatures
Xinghua Liang, Yujuan Ning, Linxiao Lan, Guanhua Yang, Minghua Li, Shufang Tang, Jianling Huang
Abstract
The stability and wide temperature performance range of solid electrolytes are the keys to the development of high-energy density all-solid-state lithium-ion batteries. In this work, a PVDF-HFP-LiClO4-Li6.4La3Zr1.4Ta0.6O12 (LLZTO) composite solid electrolyte was prepared using the solution pouring method. The PVDF-HFP-LiClO4-LLZTO composite solid electrolyte shows excellent electrochemical performance in the temperature range of 30 to 60 °C. By assembling this electrolyte into the battery, the LiFePO4/PVDF-HFP-LiClO4-LLZTO/Li battery shows outstanding electrochemical performance in the temperature range of 30 to 60 °C. The ionic conductivity of the composite electrolyte membrane at 30 °C and 60 °C is 5.5 × 10−5 S cm−1 and 1.0 × 10−5 S cm−1, respectively. At a current density of 0.2 C, the LiFePO4/PVDF-HFP-LiClO4-LLZTO/Li battery shows a high initial specific discharge capacity of 133.3 and 167.2 mAh g−1 at 30 °C and 60 °C, respectively. After 50 cycles, the reversible electrochemical capacity of the battery is 121.5 and 154.6 mAh g−1 at 30 °C and 60 °C; the corresponding capacity retention rates are 91.2% and 92.5%, respectively. Therefore, this work provides an effective strategy for the design and preparation of solid-state lithium-ion batteries.