Wu Han, Tang Ben, Du Xiaofan, Zhang Jianjun, Yu Xinrun, Wang Yantao, Ma Jun, Zhou Qian, Zhao Jingwen, Dong Shanmu, Xu Gaojie, Zhang Jinning, Xu Hai, Cui Guanglei, Chen Liquan
Qingdao Industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101 China.
College of Chemistry and Chemical Engineering Central South University Changsha 410083 China.
Adv Sci (Weinh). 2020 Nov 3;7(23):2003370. doi: 10.1002/advs.202003370. eCollection 2020 Dec.
It is demonstrated that a novel eutectic solution including 1,3,5-trioxane (TXE) and succinonitrile (SN) can be converted into solid-state polymer electrolyte (SPE) via in situ polymerization triggered by lithium difluoro(oxalato)borate (LiDFOB). It is worth noting that all the precursors (LiDFOB, TXE, and SN) of this novel SPE are totally solid and nonvolatile at room temperature, where, LiDFOB works as a lithium salt and an initiator simultaneously to avoid the introduction of impurity. It is noted that such SPE presents a considerable ionic conductivity of 1.14 × 10 S cm and a sufficiently wide electrochemical window of 4.5 V, which is significant for supporting the high-energy lithium batteries. In addition, this dedicatedly designed in situ polymerization is powerful to build kinetically favorable polymer-based protective layers on LiCoO cathode and Li metal anode simultaneously, guaranteeing outstanding cycling stability (capacity retention of 88% after 200 cycles) of 4.3 V LiCoO/lithium metal batteries at room temperature. More intriguingly, soft packed LiCoO/SPE/Li metal batteries can still light a blue light emitting diode (LED) under the harsh conditions of being bent, cut, and stroked by a hammer, demonstrating excellent safety characteristics.
结果表明，一种包含1,3,5-三氧杂环己烷（TXE）和丁二腈（SN）的新型低共熔溶剂可以通过二氟草酸硼酸锂（LiDFOB）引发的原位聚合反应转化为固态聚合物电解质（SPE）。值得注意的是，这种新型SPE的所有前体（LiDFOB、TXE和SN）在室温下均为完全固态且不挥发，其中LiDFOB同时作为锂盐和引发剂，避免了杂质的引入。值得注意的是，这种SPE具有1.14×10 S cm的可观离子电导率和4.5 V的足够宽的电化学窗口，这对于支持高能锂电池具有重要意义。此外，这种专门设计的原位聚合反应能够同时在LiCoO正极和锂金属负极上构建动力学上有利的聚合物基保护层，确保4.3 V LiCoO/锂金属电池在室温下具有出色的循环稳定性（200次循环后容量保持率为88%）。更有趣的是，软包装的LiCoO/SPE/锂金属电池在弯曲、切割和用锤子敲击等苛刻条件下仍能点亮蓝色发光二极管（LED），显示出优异的安全特性。
