Upgrading Traditional Organic Electrolytes toward Future Lithium Metal Batteries: A Hierarchical Nano-SiO<sub>2</sub>-Supported Gel Polymer Electrolyte
Yang Pu, Xiangwen Gao, Xiaolu Tian, Chengyong Shu, Yikun Yi, Pei Liu, Te Wang, Long Qu, Bingbing Tian, Mingtao Li, Wei Tang, Bolun Yang, John B. Goodenough
Abstract
Developing safe and high-energy-density lithium metal batteries (LMBs) is considered to be the focus of next-generation rechargeable batteries. However, the inevitable lithium reaction with the liquid electrolyte and the subsequent formation of Li dendrites must be overcome, and upgrading traditional liquid electrolytes is a key strategy for achieving this goal. Here, we report a nano-SiO2-supported gel polymer electrolyte (SiO2-GPE) with a hierarchical structure fabricated via in situ gelation of a traditional organic liquid electrolyte supported on a functionally modified SiO2 layer, which displayed high ionic conductivity (1.98 × 10–3 S cm–1 at 25 °C) and wide electrochemical window (>4.9 V vs Li/Li+). The LiFePO4/SiO2-GPE/Li cells exhibited a high capacity of 125.5 mAh g–1 at 1 C with capacity retention of 88.42% after 700 cycles. The superior electrochemical performance is mainly due to the highly compatible electrode/electrolyte interface and the effective inhibition of Li dendrite growth provided by the synergistic effects of this SiO2-GPE membrane.