School of Chemical Engineering, East China University of Science and Technology, Shanghai200237, China.
Chongqing Institute of Green and Intelligent Technology, Chinese Academy of Sciences, Chongqing400714, P. R. China.
ACS Appl Mater Interfaces. 2022 Dec 7;14(48):53828-53839. doi: 10.1021/acsami.2c16174. Epub 2022 Nov 29.
Compared with simplex ceramic or polymer solid electrolytes, composite solid electrolyte (CSE) is more promising for its better interfacial compatibility to electrode and high ionic conductivity simultaneously. Further, the interfacial compatibility within ceramic and polymer is considered to be more and more critical to the overall performance of solid-state batteries. Avoiding the agglomeration of ceramic particles at high loadings can improve the whole intrinsic characteristic and electrochemical performance of CSEs. Herein, we designed a CSE (EO@LLZTO-PEO), which consists of composite particles (EO@LLZTO) as a filler and polyethylene oxide (PEO) as polymer matrix. EO@LLZTO was prepared by chemically grafting polyethylene glycol monomethyl ether methacrylate (MPEG-MAA) on the micro-sized LiLaZrTaO (LLZTO) particles. By introducing of polymer containing EO segments onto LLZTO, the interfacial compatibility between LLZTO and PEO matrix is highly enhanced, and the intrinsic Li complexation capability of MPEG-MAA is improved, even at the high loading of garnet. EO@LLZTO-PEO shows a high ionic conductivity (1.91 mS cm), a broad electrochemical window (∼5.2 V vs Li/Li), and a high lithium ion transference number (0.72). The Li/EO@LLZTO-PEO/Li battery also exhibits a long cycle stability (over 1200 h of cycling). Moreover, all-solid-state batteries with LiFePO and LiNiCoMnO (NCM811) cathodes exhibit excellent cycling stability and rate performance. Consequently, enhancing the interfacial compatibility between organic and inorganic electrolytes is identified to be one of the crucial strategies for commercial solid-state lithium batteries.
与单陶瓷或聚合物固体电解质相比，复合固体电解质（CSE）具有更好的电极界面相容性和更高的离子电导率，因此更有前途。此外，陶瓷和聚合物内部的界面相容性被认为对固态电池的整体性能越来越重要。避免高负载下陶瓷颗粒的团聚可以提高 CSE 的整体固有特性和电化学性能。在这里，我们设计了一种 CSE（EO@LLZTO-PEO），它由复合颗粒（EO@LLZTO）作为填料和聚环氧乙烷（PEO）作为聚合物基体组成。EO@LLZTO 通过在微米级 LiLaZrTaO（LLZTO）颗粒上化学接枝聚乙二醇单甲醚甲基丙烯酸酯（MPEG-MAA）来制备。通过将含有 EO 段的聚合物引入到 LLZTO 中，LLZTO 和 PEO 基体之间的界面相容性得到了极大的提高，并且 MPEG-MAA 的固有 Li 络合能力得到了提高，即使在石榴石的高负载下也是如此。EO@LLZTO-PEO 表现出高离子电导率（1.91 mS cm）、宽电化学窗口（~5.2 V vs Li/Li）和高锂离子迁移数（0.72）。Li/EO@LLZTO-PEO/Li 电池也表现出长循环稳定性（超过 1200 小时的循环）。此外，具有 LiFePO 和 LiNiCoMnO（NCM811）正极的全固态电池表现出优异的循环稳定性和倍率性能。因此，增强有机和无机电解质之间的界面相容性被确定为商业固态锂电池的关键策略之一。
