通过离子溶解工程为4.6V离子电池设计宽温度电解质
Hao Zhang1, Yan Zhao2, Xiangrong Li1
1Department of Chemistry, City University of Hong Kong, Hong Kong, 999077, China.
概括
这项研究引入了用于克服温度限制的离子电池 (LIB) 的新型电解质. 新设计确保了从极寒到高温的电池性能稳定,提高了安全性和效率.
科学领域:
- 材料科学 材料科学 材料科学
- 电化学 电化学 电化学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 传统的离子电池 (LIB) 由于电解质不稳定,在极端温度下遇到性能差和安全问题.
- 乙烯碳酸盐 (EC) 基电解质和六酸 (LiPF6) 盐在低温下呈现缓慢的离子运输,在高温下呈现分解.
研究的目的:
- 为LIBs开发先进的电解质,可在广泛的温度范围内 (-60°C至45°C) 可靠运行.
- 通过协同的阴离子-离子溶解工程来增强LIB电解质的电化学稳定性和离子导电性.
主要方法:
- 开发的无EC碳酸盐溶剂与热稳定的三元盐相结合.
- 工程化阴离子-离子溶解以改善溶解动力学和离子导电性.
- 在LiCoO2 (LCO) 阴极上研究了由此产生的阴极电解质间相 (CEI) 形成.
主要成果:
- 设计的电解质表现出高离子导电率 (0.19 mS cm-1在-60°C) 和出色的热稳定性.
- 阳离子参与溶解导致富含无机物CEI,稳定高电压下LCO阴极接口.
- 在25°C的400个循环后,LCO阴极保持了88.9%的容量,在45°C的200个循环后保持了77.3%.
结论:
- 阴离子离子溶解策略使LIBs能够在广泛的温度下保持稳健的性能.
- 实现了显著的低温容量保留 (110.1mAhg-1在-35°C和92.6mAhg-1在-60°C).
- 这种方法为开发可靠的LIBs提供了一条途径,用于各种操作条件.
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