Molecular Coupling Strategy Achieving In Situ Synthesis of Agglomeration-Free Solid Composite Electrolytes
Yuanze Zhu, Yiwei Zheng, Jie Liu, Lifang Zhang, Xuyan Ni, Jinqiu Zhou, Mengfan Wang, Tao Qian, Chenglin Yan
Abstract
Solid composite electrolytes (SCEs) synergize inorganic and polymer merits for viable commercial application. However, inferior filler–polymer interfacial stability ultimately leads to the agglomeration of inorganic particles and greatly impedes Li + migration. Herein, triethoxyvinylsilane (VTEO) is employed to form a strong chemical interaction between poly(vinylene carbonate) (PVC) and montmorillonite (MMT) via in situ solidification, which eliminates the agglomeration and improves interfacial compatibility. Consequently, the obtained solid composite electrolytes (PVC-s-MMT) achieve increased Li + conductivity (0.4 mS cm –1 at 25 °C), enhanced transference number (0.74), and increased oxidation potential (5.2 V). The Li/PVC-s-MMT/LiFePO 4 cells exhibit outstanding cycling performance (>99.5% after 600 cycles) at 1C at room temperature. Moreover, density functional theory (DFT) calculations are applied to uncover the fast interfacial conducting channels of PVC-s-MMT. Our work provides a feasible in situ synthesis method to prepare agglomeration-free SCEs, which is highly compatible with existing battery production processes of liquid electrolytes.