Polydopamine-Induced Metal–Organic Framework Network-Enhanced High-Performance Composite Solid-State Electrolytes for Dendrite-Free Lithium Metal Batteries
Lai Wei, Xin Xu, Kang Xi, Xiaobei Shi, Xiang Cheng, Yue Lei, Yunfang Gao
Abstract
Due to the high safety, flexibility, and excellent compatibility with lithium metals, composite solid-state electrolytes (CSEs) are the best candidates for next-generation lithium metal batteries, and the construction of fast and uniform Li + transport is a critical part of the development of CSEs. In this paper, a stable three-dimensional metal–organic framework (MOF) network was obtained using polydopamine as a medium, and a high-performance CSE reinforced by the three-dimensional MOF network was constructed, which not only provides a continuous channel for Li + transport but also restricts large anions and releases more mobile Li + through a Lewis acid–base interaction. This strategy endows our CSEs with an ionic conductivity (7.1 × 10 –4 S cm –1 at 60 °C), a wide electrochemical window (5.0 V), and a higher Li + transfer number (0.54). At the same time, the lithium symmetric batteries can be stably cycled for 2000 h at 0.1 mA cm –2, exhibiting excellent electrochemical stability. The LiFePO 4 /Li cells have a high initial discharge specific capacity of 153.9 mAh g –1 at 1C, with a capacity retention of 80% after 915 cycles. This paper proposes an approach for constructing three-dimensional MOF network-enhanced CSEs, which provides insights into the design and development of MOFs for the positive effects of high-performance CSEs.