Yan Yiyuan, Ju Jiangwei, Dong Shanmu, Wang Yantao, Huang Lang, Cui Longfei, Jiang Feng, Wang Qinglei, Zhang Yanfen, Cui Guanglei
Qingdao Industrial Energy Storage Research Institute Qingdao Institute of Bioenergy and Bioprocess Technology Chinese Academy of Sciences Qingdao 266101 P. R. China.
Adv Sci (Weinh). 2021 Mar 3;8(9):2003887. doi: 10.1002/advs.202003887. eCollection 2021 May.
Solid-state lithium battery promises highly safe electrochemical energy storage. Conductivity of solid electrolyte and compatibility of electrolyte/electrode interface are two keys to dominate the electrochemical performance of all solid-state battery. By in situ polymerizing poly(ethylene glycol) methyl ether acrylate within self-supported three-dimensional porous LiAlTi(PO) framework, the as-assembled solid-state battery employing 4.5 V LiNiMnCoO cathode and Li metal anode demonstrates a high Coulombic efficiency exceeding 99% at room temperature. Solid-state nuclear magnetic resonance results reveal that Li migrates fast along the continuous LiAlTi(PO) phase and LiAlTi(PO)/polymer interfacial phase to generate a fantastic conductivity of 2.0 × 10 S cm at room temperature, which is 56 times higher than that of pristine poly(ethylene glycol) methyl ether acrylate. Meanwhile, the in situ polymerized poly(ethylene glycol) methyl ether acrylate can not only integrate the loose interfacial contact but also protect LiAlTi(PO) from being reduced by lithium metal. As a consequence of the compatible solid-solid contact, the interfacial resistance decreases significantly by a factor of 40 times, resolving the notorious interfacial issue effectively. The integrated strategy proposed by this work can thereby guide both the preparation of highly conductive solid electrolyte and compatible interface design to boost practical high energy density all solid-state lithium metal battery.
固态锂电池有望实现高度安全的电化学储能。固体电解质的电导率和电解质/电极界面的兼容性是决定全固态电池电化学性能的两个关键因素。通过在自支撑的三维多孔LiAlTi(PO)骨架中原位聚合聚（乙二醇）甲基醚丙烯酸酯，所组装的采用4.5 V LiNiMnCoO正极和锂金属负极的固态电池在室温下表现出超过99%的高库仑效率。固态核磁共振结果表明，锂沿着连续的LiAlTi(PO)相和LiAlTi(PO)/聚合物界面相快速迁移，在室温下产生了高达2.0×10 S cm的优异电导率，这比原始的聚（乙二醇）甲基醚丙烯酸酯高56倍。同时，原位聚合的聚（乙二醇）甲基醚丙烯酸酯不仅可以整合松散的界面接触，还可以保护LiAlTi(PO)不被锂金属还原。由于兼容的固-固接触，界面电阻显著降低了40倍，有效解决了臭名昭著的界面问题。这项工作提出的集成策略能够指导高导电固体电解质的制备和兼容界面设计，以推动实用的高能量密度全固态锂金属电池的发展。
