Li Xintong, Han Xiaoqi, Zhang Huanrui, Hu Rongxiang, Du Xiaofan, Wang Peng, Zhang Botao, Cui Guanglei
College of Chemical Technology, Qingdao University, Qingdao 266071, P. R. China.
Qingdao Industrial Energy Storage Research Institute, Qingdao Institute of Bioenergy and Bioprocess Technology, Chinese Academy of Sciences, Qingdao 266101, P. R. China.
ACS Appl Mater Interfaces. 2020 Nov 18;12(46):51374-51386. doi: 10.1021/acsami.0c13520. Epub 2020 Oct 20.
The development of gel polymer electrolytes (GPEs) is considered to be an effective strategy to drive practical applications of high-voltage lithium metal batteries (HLMBs). However, rare GPEs that can satisfy the demands of HLMBs have been developed because of the limited compatibility with lithium anodes and high-voltage cathodes simultaneously. Herein, a novel strategy for constructing polymer matrixes with a customized frontier orbital energy for GPEs is proposed. The as-investigated polymer matrix (P(CUMA-NPF))-based GPE (P(CUMA-NPF)-GPE) obtained random polymerization delivers a wide voltage window (0-5.6 V Li/Li), large lithium-ion transference number (, 0.61), and superior electrode/electrolyte interface compatibility. It is to be noted that such a of P(CUMA-NPF)-GPE, which is one of the largest among high-voltage GPEs in a fair comparison, results from the high dissociation of lithium salts and effective anion immobilization abilities of P(CUMA-NPF). Ultimately, the as-assembled HLMB delivers more enhanced cycle performance than its counterpart of commercial liquid electrolytes. It is also demonstrated that P(CUMA-NPF) can scavenge the active PF intermediate generated in the electrolyte at the anode side, thus suppressing the PF-mediated decomposition reaction of carbonates. This work will enlighten the rational structure design of GPEs for HLMBs.
凝胶聚合物电解质（GPEs）的开发被认为是推动高压锂金属电池（HLMBs）实际应用的有效策略。然而，由于与锂负极和高压正极的兼容性同时受限，很少有能满足HLMBs要求的GPEs被开发出来。在此，提出了一种为GPEs构建具有定制前沿轨道能量的聚合物基体的新策略。通过无规聚合得到的所研究的基于聚合物基体（P（CUMA-NPF））的GPE（P（CUMA-NPF）-GPE）具有宽电压窗口（0 - 5.6 V Li/Li）、大锂离子迁移数（，0.61）以及优异的电极/电解质界面兼容性。需要注意的是，在公平比较中，P（CUMA-NPF）-GPE的这种性能是高压GPEs中最大的之一，这源于锂盐的高解离度以及P（CUMA-NPF）有效的阴离子固定能力。最终，所组装的HLMB比其使用商业液体电解质的对应物具有更优异的循环性能。还证明了P（CUMA-NPF）可以清除在阳极侧电解质中产生的活性PF中间体，从而抑制PF介导的碳酸盐分解反应。这项工作将为HLMBs的GPEs合理结构设计提供启示。
