Abstract
Traditional dual-ion lithium salts have been widely used in solid polymer lithium-metal batteries(LMBs).Nevertheless,concentration polarization caused by uncontrolled migration of free anions has severely caused the growth of lithium dendrites.Although single-ion conductor polymers(SICP)have been devel-oped to reduce concentration polarization,the poor ionic conductivity caused by low carrier concentra-tion limits their application.Herein,a dual-salt quasi-solid polymer electrolyte(QSPE),containing the SICP network as a salt and traditional dual-ion lithium salt,is designed for retarding the movement of free anions and simultaneously providing sufficient effective carriers to alleviate concentration polariza-tion.The dual salt network of this designed QSPE is prepared through in-situ crosslinking copolymeriza-tion of SICP monomer,regular ionic conductor,crosslinker with the presence of the dual-ion lithium salt,delivering a high lithium-ion transference number(0.75)and satisfactory ionic conductivity(1.16 × 10-3 S cm-1 at 30 ℃).Comprehensive characterizations combined with theoretical calculation demonstrate that polyanions from SICP exerts a potential repulsive effect on the transport of free anions to reduce concentration polarization inhibiting lithium dendrites.As a consequence,the Li‖LiFePO4 cell achieves a long-cycle stability for 2000 cycles and a 90％capacity retention at 30 ℃.This work provides a new perspective for reducing concentration polarization and simultaneously enabling enough lithium-ions migration for high-performance polymer LMBs.
基金项目
National Natural Science Foundation of China(52273081)
National Natural Science Foundation of China(22278329)
Natural Science Basic Research Program of Shaanxi(2022TD-27)
Natural Science Basic Research Program of Shaanxi(2020-JC-09)
Qin Chuangyuan Talent Project of Shaanxi Province(OCYRCXM-2022-308)
State Key Laboratory for Electrical Insulation and Power Equipment(EIPE23125)
the"Young Talent Support Plan"of Xi'an Jiaotong University()
NETL
NSTL
万方数据