A thermoresponsive composite separator loaded with paraffin@SiO_(2) microparticles for safe and stable lithium batteries

作     者：Hao Dong Peican Wang Shuaishuai Yan Yingchun Xia Baoguo Wang Xiaolin Wang Kai Liu Hao Dong;Peican Wang;Shuaishuai Yan;Yingchun Xia;Baoguo Wang;Xiaolin Wang;Kai Liu

作者机构：The State Key Laboratory of Chemical EngineeringDepartment of Chemical EngineeringTsinglma UniversityBeijing 100084China 

出 版 物：《Journal of Energy Chemistry》 (能源化学（英文版）)

年 卷 期：2021年第30卷第11期

页      面：423-430,I0009页

核心收录：

学科分类：0808[工学-电气工程] 07[理学] 070205[理学-凝聚态物理] 08[工学] 080501[工学-材料物理与化学] 0805[工学-材料科学与工程（可授工学、理学学位）] 0702[理学-物理学] 

基　　金：This work is supported by the National Key Research and Development Program,China(2019YFC0810703) the National Natural Science Foundation of China(22071133) the Tsinghua-Foshan Innovation Special Fund(TFISF),China(2019THFS0128) 

主　　题：Thermally-induced shutdown Separator Paraffin@SiO_(2) Lithium batteries Safety Wettability 

摘      要：Lithium-ion batteries (LIBs)-related accidents have been reported for years and safety issues are stumbling blocks for the practical applications of lithium metal batteries (LMBs) with higher energy density. More effective strategies to shut down the battery at the early stage of thermal runaway with less side effects on the electrochemical performance are greatly desired. In this work, the core–shell structural paraffin@SiO_(2) microparticles were synthesized by in situ emulsion interfacial hydrolysis and polycondensation and the paraffin@SiO_(2)-loaded separator (PSS) was prepared by a facile filtration method. The introduction of hydrophilic silica shells in paraffin@SiO_(2) enhanced the wettability of carbonate electrolyte with the composite separator and improved the processability of soft paraffin. As a result, when used in LMBs at room temperature, the cell with PSS inside had a more uniform deposition of lithium, a much lower overpotential and a more stable electrochemical performance than the cell with the blank separator or the conventional pure paraffin-loaded separator inside. More significantly, when a heating stimulation (i.e. 115 ℃) was subjected to the cell with PSS inside, the paraffin in the core of paraffin@SiO_(2) could be released, blocking the gaps between particles and the pores in the separator and efficiently stopping the transportation of Li+ between two electrodes, resulting in the thermally-induced shutdown of the cell below the melting temperature of PE (~135 ℃) in the Celgard2325 separator. The core–shell structure of paraffin@SiO_(2) enables the maintaining of each component’s benefits while avoiding each one’s drawbacks by elaborating microstructural design. Therefore, the conventional dilemma between the electrochemcial performance and safety of LMBs could be solved in the future.