A 4 V Cathode Compatible, Superionic Conductive Solid Polymer Electrolyte for Solid Lithium Metal Batteries with Long Cycle Life
A 4 V Cathode Compatible, Superionic Conductive Solid Polymer Electrolyte for Solid Lithium Metal Batteries with Long Cycle Life
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DOI：
10.1021/acsaem.8b01138
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发表时间：
2018-11-01
影响因子：
6.4
通讯作者：
Zhu, Yu
中科院分区：
文献类型：
--
作者：
Liang, Wenfeng;Shao, Yunfan;Zhu, Yu
研制了一种用于大容量阴极的高导电性和电化学稳定性的双盐固体聚合物电解质。采用相图方法为实现高离子电导率(30℃时超过1.76毫秒/厘米)提供了合理的指导。不同盐的协同作用使固相电极具有更好的电化学稳定性，线性扫描伏安法的电化学窗口为0~5V(vsLi+/Li)，金属锂电池(LMB)的电化学窗口高达4.15V。在0.08~0.5 mA/cm(2)的电流密度下，固相萃取在锂电镀/剥离实验中表现出优异的长期稳定性。固态金属锂电池(LiNi0.8Co0.15Al0.05O2，NCA，正极)在30℃下以0.1C的倍率首次容量为165mAh/g，以1C的倍率首次容量为113mAh/g，在1C的倍率下，前1000次循环的平均库仑效率超过99.99%，1000次循环后的容量保持率为66%。此外，初始100次循环后的每循环容量衰减率仅为0.017%。结果表明，固相萃取剂是一种很有前途的高能量密度固态金属锂电池电解液。
A highly conductive and electrochemically stable dual-salt solid polymer electrolyte (SPE) for a high-capacity cathode was developed. A phase-diagram approach was adopted to provide rational guidance for achieving a high ionic conductivity (over 1.76 mS/cm at 30 degrees C). The synergy of combining different salts rendered superior electrochemical stability to the SPE with an electrochemical window from 0 to 5 V (vs Li+/Li) in linear sweep voltammetry and up to 4.15 V in lithium metal batteries (LMBs). The SPE exhibited outstanding long-term stability performance in lithium plating/stripping experiments under current densities from 0.08 to 0.5 mA/cm(2). The solid-state lithium metal batteries (with an LiNi0.8Co0.15Al0.05O2, NCA, cathode) exhibited initial capacities of 165 mAh/g at a rate of 0.1 C and 113 mAh/g at a rate of 1 C at 30 degrees C. The average Coulombic efficiency of solid-state batteries was over 99.99% in the first 1000 cycles at a rate of 1 C, and the capacity retention was 66% after 1000 cycles. In addition, the per cycle capacity fading after the initial 100 cycles was only 0.017%/cycle. The results demonstrate that the SPE is a promising candidate electrolyte for a high-energy-density solid-state lithium metal battery.