通过调整电解质化学,使离子电池在快速操作条件下能够稳定运行
Zehao Cui1, Chen Liu1, Arumugam Manthiram1
1Materials Science and Engineering Program and Texas Materials Institute, The University of Texas at Austin, Austin, TX, 78712, USA.
Advanced materials (Deerfield Beach, Fla.)
|August 16, 2024
概括
没有乙烯碳酸盐 (EC) 的新电解质使离子电池能够快速充电和在低温下保持稳定的性能. 甲基三乙酸盐 (MTFA) 的添加改善了固体电解质间相,以增强电池循环.
科学领域:
- 电化学 电化学 电化学
- 材料科学 材料科学 材料科学
- 储能 储能 储能 储能 储能 储能
背景情况:
- 由于电解质的限制,离子电池面临快速充电和低温运行方面的挑战.
- 基于乙烯碳酸盐 (EC) 的电解质具有低导电性,并形成有害的固体电解质界面 (SEI),阻碍Li+离子扩散.
- 开发先进的电解质对于在苛刻的条件下提高电池性能至关重要.
研究的目的:
- 设计和研究新的无EC电解质,以提高快充和低温离子电池的性能.
- 探索甲基三乙酸盐 (MTFA) 作为辅溶剂在改变SEI特性中的作用.
- 评估使用开发的电解质的电池的长期循环稳定性和速率能力.
主要方法:
- 合成了一系列无EC电解质,将MTFA纳入LiPF6-二甲基碳酸-乙烯碳酸系统.
- 描述了电极上的溶解结构和SEI形成.
- 在各种充电速率和温度下测试了商用1Ah石墨液晶LiNi0.8Mn0.1Co0.1O2袋式电池.
主要成果:
- 新型电解质促进了薄而坚固的SEI的形成,并改善了Li+离子扩散动力学.
- 电池在3C和4C充电速率下在3000个循环中显示了80%的容量保留.
- 在-20°C,一个1Ah电池在2°C放电时保持0.65Ah容量,在C/5循环时显示最小的色.
结论:
- 在没有EC的电解质中将MTFA作为辅溶剂,显著提高快充和低温电池的性能.
- 开发的电解质为下一代离子电池提供了有前途的解决方案,这些电池需要高功率和广泛的操作温度范围.
- 电解质工程是克服离子电池技术关键局限性的强大策略.
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