在不可燃性离子电池的水性电解质中加强了O-H键
Shengxi Li1, Yanxin Shang1, Xuening Ren1
1Beijing Key Laboratory of Environmental Science and Engineering, School of Materials Science and Engineering, Beijing Institute of Technology, Beijing 100081, China.
ACS nano
|April 24, 2025
概括
研究人员开发了一种用于水性离子电池 (ALIB) 的新型电解质,可以抑制水的活动. 这提高了在低温下电池的性能,并扩大了电化学稳定性窗口,以实现更安全,高密度的能量存储.
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:
- 水性离子电池 (ALIB) 具有固有的安全性和环境优势.
- 主要限制包括水的狭窄电化学稳定性窗口 (1.23V) 和高点 (0°C),阻碍能量密度和低温操作.
- 演化反应 (HER) 和水解离是主要的挑战.
研究的目的:
- 建立一个电解质设计原则,以抑制ALIB中的水活动.
- 为了提高ALIBs的电化学稳定性窗口和低温性能.
- 为性HER机制提供原子层面的洞察力.
主要方法:
- 使用N,N-二甲基形式胺 (DMF),一个极性溶剂,通过分子间联结来加强水中的O-H键.
- 使用KOH调节电解质pH以创建性环境,抑制水解离并增加HER过量的潜力.
- 在一个LiMn2O4/Li4Ti5O12全细胞中研究了设计的LD1.7W0.6-KOH电解质的特性和性能.
主要成果:
- LD1.7W0.6-KOH电解质实现了低于-82°C的结点,并扩大了4.3V的电化学稳定窗口.
- 全细胞表现出稳定的循环性能:2000个周期在30°C (6°C速率,99%的库伦比克效率) 和超过1950个周期在0°C.
- 通过溶剂-水相互作用和pH调节,证明了抑制水活动.
结论:
- 开发的电解质设计原理有效地抑制了水的活动,使ALIB能够在低温下运行,并且具有更广泛的电化学稳定性.
- 这种方法为推进高能量密度和安全的水性电池提供了一个可行的策略.
- 这项研究提供了对性HER的基本见解,指导了未来的电解质开发.
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