1. Two-dimensional silica enhanced solid polymer electrolyte for lithium metal batteries
- Author
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Luo, Zhihong, Li, Weiyong, Guo, Chong, Song, Ya, Zhou, Mingxia, Shi, Yan, Xu, Jing, Li, Long, Shi, Bin, Ouyang, Quansheng, Shao, Jiao-Jing, and Zhou, Guangmin
- Abstract
Solid polymer electrolytes (SPEs) are promising substitutes for current flammable liquid electrolytes to achieve high-safety and high-energy-density lithium metal batteries. Polyethylene oxide (PEO) based solid polymer electrolytes have attracted increasing attention because of their excellent flexibility, manufacturability, light weight, and low-cost processing, while they often suffer from low ionic conductivity at room temperature, low lithium transference number and unsatisfactory interfacial resistance, which largely restrain their practical application. Herein, two-dimensional holey silica nanosheets (2D-HSN) as the fillers, together with LiNO3as the electrolyte additive, are introduced in a PEO/poly(vinylidene fiuoride-co-hexafluoropropylene) (PVDF-HFP) blended polymer matrix to obtain a SPE. The incorporation of HSN filler creates supplementary channels for lithium ion migration and lowers the crystallinity of the polymer, thereby facilitating the movement of lithium ions. The HSN-based SPE demonstrates higher ionic conductivity up to 3.7 × 10−4 S cm−1at 30 °C, larger Li+transference number close to 0.34, and more stable lithium plating/stripping than that without the fillers, and HSN can promote the formation of more stable solid electrolyte interphase (SEI) layer. The as-assembled LiFePO4||Li batteries deliver a high specific capacity of 159 mA h g−1with the capacity retention of 95.5% after 200 cycles at 30 °C, as well as superior rate performance and cycling stability compared to that using the blank SPE.
- Published
- 2024
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