Xie Binxuan, Chen Shimou, Chen Yong, Liu Lili
College of Chemistry and Materials Engineering, Beijing Technology and Business University Beijing 100048 China
Institute of Process Engineering, Chinese Academy of Sciences Beijing 100190 China
RSC Adv. 2021 Apr 14;11(23):14036-14046. doi: 10.1039/d1ra02641k. eCollection 2021 Apr 13.
Lithium-ion batteries using either liquid electrolytes or solid electrolytes have been extensively studied in recent years, but both of these encounter safety risks such as flammability of liquid electrolytes and uncontrolled dendrite growth. In this study, a sandwich gel polymer electrolyte (SGPE) with a thermal shutdown function was developed to resolve the safety issues. By adjustment of surface pore size of the SGPE, lithium dendrite growth is suppressed. Due to the sandwich structure design, the SGPE can effectively respond to an overheating environment, regulate lithium ion transport and inhibit the penetration of lithium dendrite, demonstrating a remarkably high safety of the batteries, especially at high temperature or under thermal runaway circumstances. In addition, the LiFePO/SGPE/Li battery exhibits a high reversible capacity of 135 mA h g at 1C and maintains high capacity retention (>95%) after 200 charge-discharge cycles. This study shows a great advantage to handle thermal abuse and a stable lithium anode, suggesting a promising approach to the high safety lithium metal batteries.
近年来，使用液体电解质或固体电解质的锂离子电池得到了广泛研究，但这两种电池都存在安全风险，如液体电解质的易燃性和枝晶生长失控。在本研究中，开发了一种具有热关闭功能的三明治凝胶聚合物电解质（SGPE）来解决安全问题。通过调整SGPE的表面孔径，抑制了锂枝晶的生长。由于采用了三明治结构设计，SGPE能够有效应对过热环境，调节锂离子传输并抑制锂枝晶的穿透，在电池尤其是高温或热失控情况下表现出极高的安全性。此外，LiFePO/SGPE/Li电池在1C下具有135 mA h g的高可逆容量，在200次充放电循环后保持高容量保持率（>95%）。这项研究显示了处理热滥用和稳定锂负极方面的巨大优势，为高安全性锂金属电池提供了一种有前景的方法。
