Intermolecular Chemistry in High-Entropy Solid Polymer Electrolyte Enabling Room Temperature Solid-State Lithium Metal Batteries
Hui-Juan Guo, Rui Shu, Yaxin Xie, Xueying Wang, Haonan Wu, Yuexian Song, Jianxin Tian, Fanpeng Cheng, Yangyang Guo*, Tingyu Zhu, Lijuan Shi*, Rui Wen, and Qun Yi*
doi：10.1039/d5ta03675e
Abstract: Solid polymer electrolytes with excellent processivity have attracted tremendous attention in advanced solid-state lithium metal batteries (SSLMBs), while their application remains a tough challenge due to the trade-off between high ionic conductivity and well mechanical strength. Here, via in situ polymerization, the unique Li+ solvation structures as well as abundant hydrogen bonds are inserted into a high-entropy supramolecular zwitterion solid polymer electrolyte (HESZ-SPE), significantly facilitating Li+ transport and improving mechanical properties at room temperature (RT). The in situ polymerized HESZ-SPE exhibits high electrochemical stability and excellent interfacial stability, and thus implements the uniform Li+ plating/stripping that revealed by COMSOL simulation. Remarkably, the HESZ-SPE achieves the balance in excellent mechanical strength, high ionic conductivity (4.60 × 10-3 S cm−1), an appreciable Li+ transference number (0.86) for RT SSLMBs. Consequently, the HESZ-SPE provides an excellent cycling stability, high coulombic efficiency and favorable rate capability at RT in SSLMBs, holding great promise in enabling high-performance electrochemical energy storage
具有优异加工性能的固态聚合物电解质在先进固态锂金属电池（SSLMBs）中受到广泛关注，然而其实际应用仍面临挑战，主要难点在于如何同时实现高离子电导率与良好的机械强度。本文通过原位聚合的方法，将独特的Li⁺溶剂化结构以及丰富的氢键引入一种高熵超分子两性离子固态聚合物电解质（HESZ-SPE）中，从而显著促进了Li⁺的传输性能，并在室温下（RT）提升了其机械性能。原位聚合得到的HESZ-SPE展现出优异的电化学稳定性和界面稳定性，并通过COMSOL模拟验证了其均匀的Li⁺沉积/剥离行为。令人瞩目的是，该电解质在机械强度、离子电导率（4.60 × 10⁻³ S cm⁻¹）和锂离子迁移数（0.86）等方面实现了良好平衡，满足了室温固态锂金属电池的应用需求。因此，HESZ-SPE在室温下表现出优异的循环稳定性、高库伦效率以及良好的倍率性能，在推动高性能电化学储能器件的发展方面展现出巨大潜力。
