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Homogeneous and Fast Ion Conduction of PEO‐Based Solid‐State Electrolyte at Low Temperature
Author(s) -
Xu Shengjun,
Sun Zhenhua,
Sun Chengguo,
Li Fan,
Chen Ke,
Zhang Zhihao,
Hou Guangjin,
Cheng HuiMing,
Li Feng
Publication year - 2020
Publication title -
advanced functional materials
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 6.069
H-Index - 322
eISSN - 1616-3028
pISSN - 1616-301X
DOI - 10.1002/adfm.202007172
Subject(s) - electrolyte , materials science , ethylene oxide , ionic conductivity , lithium (medication) , chemical engineering , faraday efficiency , crystallization , oxide , ion , ionic bonding , fast ion conductor , polymer , chemistry , organic chemistry , composite material , copolymer , medicine , electrode , engineering , metallurgy , endocrinology
Poly(ethylene oxide) (PEO)‐based electrolytes are promising for all‐solid‐state batteries but can only be used above room temperature due to the high‐degree crystallization of PEO and the intimate affinity between ethylene oxide (EO) chains and lithium ions. Here, a homogeneous‐inspired design of PEO‐based solid‐state electrolytes with fast ion conduction is proposed. The homogeneous PEO‐based solid‐state electrolyte with an adjusted succinonitrile (SN) and PEO molar ratio simultaneously suppresses the PEO crystallization and mitigates the affinity between EO and Li + . By adjusting the molar ratio of SN to PEO (SN:EO ≈ 1:4), channels providing fast Li + transport are formed within the homogeneous solid‐state polymer electrolyte, which increases the ionic conductivity by 100 times and enables their application at a low temperature (0–25 °C), together with the uniform lithium deposition. This modified PEO‐based electrolyte also enables a LiFePO 4 cathode to achieve a superior Coulombic efficiency (>99%) and have a long life (>750 cycles) at room temperature. Moreover, even at a low temperature of 0 °C, 82% of its room‐temperature capacity remains, demonstrating the great potential of this electrolyte for practical solid‐state lithium battery applications.