Two-dimensional silica enhanced solid polymer electrolyte for lithium metal batteries (Open Access)--颗粒学报PARTICUOLOGY

Luo, Z., Li, W., Guo, C., Song, Y., Zhou, M., Shi, Y., . . . Zhou, G. (2024). Two-dimensional silica enhanced solid polymer electrolyte for lithium metal batteries. Particuology, 85, 146-154. https://doi.org/10.1016/j.partic.2023.04.002

Two-dimensional silica enhanced solid polymer electrolyte for lithium metal batteries (Open Access)

Zhihong Luo ^{a 1}, Weiyong Li ^{a 1}, Chong Guo ^a, Ya Song ^a, Mingxia Zhou ^a, Yan Shi ^a, Jing Xu ^a, Long Li ^a, Bin Shi ^b, Quansheng Ouyang ^c, Jiao-Jing Shao ^a *, Guangmin Zhou ^d *

a School of Materials and Metallurgy, Guizhou University, Guiyang, 550025, China
b State Key Laboratory of Advanced Chemical Power Sources, Zunyi, 563003, China
c Graphene Materials Engineering Research Center of Guizhou Colleges and Universities, Guiyang, 550025, China
d Tsinghua-Berkeley Shenzhen Institute & Tsinghua Shenzhen International Graduate School, Tsinghua University, Shenzhen, 518055, China

10.1016/j.partic.2023.04.002

Volume 85, February 2024, Pages 146-154

Received 2 March 2023, Revised 13 April 2023, Accepted 16 April 2023, Available online 25 April 2023, Version of Record 30 April 2023.

E-mail: shaojiao_jing@163.com; xjshao@gzu.edu.cn; guangminzhou@sz.tsinghua.edu.cn

Highlights

• 2D holey amorphous silica prepared by ion exchange exfoliation followed by selective etching.

• Migration of lithium ions were promoted by creating lithium ion migration channels in SPE.

• Lithium metal batteries with SPE show a high specific capacity and a capacity retention.

• Lithium metal pouch cells displays high safety and can work even under rigorous conditions.

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 LiNO₃ as 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⁻¹ at 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⁻¹ with 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.

Graphical abstract

Keywords

Vermiculite nanosheets; Two-dimensional silica; Solid polymer electrolytes; Fillers; Lithium metal batteries

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