Researchers in China report that commercialized liquid electrolyte can be easily converted into a novel quasi-solid gel polymer electrolyte (GPE) via a simple and efficient in situ gelation strategy. The newly developed GPE exhibits elevated protective effects on Li metal anodes and has universality for diversified cathodes including, but not restricted to, sulfur, olivine-type LiFePO₄, and layered LiNi_0.6Co_0.2Mn_0.2O₂, revealing tremendous potential in promoting the large-scale application of future Lithium metal batteries (LMBs).

An open-access paper on their work is published in Science Advances.

Lithium metal batteries (LMBs) consisting of lithium (Li) anodes (3860 mAh g⁻¹), high-energy cathodes, and stable electrolytes are among the most motivating research territories of lithium secondary batteries, but it is also acknowledged that the practical application of LMBs is seriously impeded by uncontrolled Li dendrites and pulverization under liquid electrolytes (LEs) commonly used in LIBs. Tremendous efforts have been dedicated through many approaches to overcome the above challenges, among which the exploration of safe and stable electrolytes with compatibility to metallic Li is particularly critical and indispensable.

Today research on gel polymer electrolytes (GPEs) and solid polymer electrolytes (SPEs) is receiving extensive interest. As the electrolytes for LMBs, they are featured with superior stabilities toward Li anodes over traditional LEs, but the interfacial problems of GPEs and SPEs within integrated batteries, especially the separation between cathode materials and electrolytes, need to be further resolved.

… Herein, a new strategy is crafted to convert traditional ether-based 1,3-dioxolane (DOL) and 1,2-dimethoxyethane (DME) LEs into a novel quasi-solid GPE simply with the addition of commercial lithium hexafluorophosphate (LiPF₆).

—Liu et al.

The in-situ gelation strategy is, in essence, to use LiPF₆ to induce the cationic polymerization of ether-based 1,3-dioxolane and 1,2-dimethoxyethane liquid electrolyte under ambient temperature.

The researchers found that the GPE exhibits enormous potential as a reliable electrolyte for next-generation LMBs.

Resources

• Feng-Quan Liu, Wen-Peng Wang, Ya-Xia Yin, Shuai-Feng Zhang, Ji-Lei Shi, Lu Wang, Xu-Dong Zhang, Yue Zheng, Jian-Jun Zhou, Lin Li, Yu-Guo Guo (2018) “Upgrading traditional liquid electrolyte via in situ gelation for future lithium metal batteries” Science Advances Vol. 4, no. 10, eaat5383 doi: 10.1126/sciadv.aat5383