A Dual‐Salt Gel Polymer Electrolyte with 3D Cross‐Linked Polymer Network for Dendrite‐Free Lithium Metal Batteries

Abstract

Lithium metal batteries show great potential in energy storage because of their high energy density. Nevertheless, building a stable solid electrolyte interphase (SEI) and restraining the dendrite growth are difficult to realize with traditional liquid electrolytes. Solid and gel electrolytes are considered promising candidates to restrain the dendrites growth, while they are still limited by low ionic conductivity and incompatible interphases. Herein, a dual‐salt (LiTFSI‐LiPF6) gel polymer electrolyte (GPE) with 3D cross‐linked polymer network is designed to address these issues. By introducing a dual salt in 3D structure fabricated using an in situ polymerization method, the 3D‐GPE exhibits a high ionic conductivity (0.56 mS cm−1 at room temperature) and builds a robust and conductive SEI on the lithium metal surface. Consequently, the Li metal batteries using 3D‐GPE can markedly reduce the dendrite growth and achieve 87.93% capacity retention after cycling for 300 cycles. This work demonstrates a promising method to design electrolytes for lithium metal batteries.

A polymeric composite protective layer for stable Li metal anodes

“…Hence, the local current density is significantly increased, which leads to uneven Li deposition. It has been reported that the localcurrent density can be reduced by using high-surface-area current collectors [38][39][40][41][42][43][44][45][46][47], which results in a significantly improved cycling performance. Hence, only a uniform and strong artificial SEI, instead of native SEI, can alter the fundamental self-amplifying behavior of dendritic growth [2,26,[48][49][50][51][52][53][54][55][56][57][58][59].…”

Formulation of Blended‐Lithium‐Salt Electrolytes for Lithium Batteries

“…Reproduced with permission from Ref. , Copyright 2018 Wiley‐VCH. b) Mechanism of the LiPF 6 ‐induced polymerization of DOL.…”

A Review of Functional Separators for Lithium Metal Battery Applications

“…Similarly, Li and co-workers designed a novel dual-salt lithium bis(trifluoromethanesulfonyl)imide–lithium hexafluorophosphate (LiTFSI-LiPF 6 ) GPE with a 3D cross-linked polymer network [ 162 ] ( Figure 17 b). The 3D cross-linked polymer network by poly(ethylene glycol) diacrylate (PEGDA) and ethoxylated trimethylolpropane triacrylate was formed using dual-salts.…”

“…( b ) Step process for in situ polymerization of GPE. Reprinted with permission from [ 162 ]. Copyright (2018) John Wiley and Sons.…”