A gel porous single-ion conducting polyelectrolyte with double anionic functional group for enhancing lithium ion battery performance

摘要

A lithiated polyanion with double anionic functional group was synthesized via copolymerization with of lithiated tetramethanolatoborate and lithiated bis(4-hydroxy benzene sulfonyl)imide, which generated a gel porous single-ion conducting polyelectrolyte (SIPE) in situ after blending with PVDF. The reciprocal delocalized of double anionic functional group can promotes Li+ dissociation while the porous structure ensures the solvent absorption adequate to facilitate Li+ transportation. Upon which, a high ionic conductivity of 2.6 x 10(-4) S cm(-1) can be achieved at gel state. Moreover, the gel SIPE endows a larger lithium ion transference number (0.78) and wider electrochemical window (4.4 V, 30 degrees C). In battery test, this gel SIPE exhibits stable galvanostatic Li plating/stripping behavior in Li symmetrical cell and superior cyclic stability in LiFePO4/Li cell. (C) 2021 Elsevier B.V. All rights reserved.