低电子负性的阴性高性兴奋剂触发了离子电池中高无合离子分层阴极的稳定阳离子再氧化活性
Pengrui Liang1, Kaiwen Qi1, Shiyuan Chen1
1School of Chemistry and Materials Science, University of Science and Technology of China, Hefei, 230026, P. R. China.
Angewandte Chemie (International ed. in English)
|January 5, 2024
概括
在没有的阴极中使用高性兴奋剂可以通过稳定结构并使离子氧化还原活性成为可能,从而提高离子电池的容量. 这一策略提高了先进电池材料的能量密度和循环稳定性.
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:
- 商业离子电池 (LIB) 使用LiNi0.8Co0.1Mn0.1O2 (NCM-811) 阴极,因为它们的含量很高,因此能耗密度很高.
- 限制包括80%以上的Ni含量的阴离子不稳定性和导致氧气释放的阳离子不稳定性,阻碍了阳离子氧化还原利用.
- 目前的战略重点是增加含量,但结构性不稳定性阻碍了进一步的产能增长.
研究的目的:
- 开发一种新的高Ni,Co-free分层阴极材料.
- 通过稳定阴离子和阴离子结构来提高电化学性能.
- 探索阴离子氧化还原活性在LIBs中增加能量密度的潜力.
主要方法:
- 使用低电子负性的阴离子高兴奋剂策略制造一个无Co分层阴极 (LiNi0.8 Mn0.12 Al0.02 Ti0.02 Cr0.02 Fe0.02 O2).
- 对各种高性兴奋剂组合替代进行比较分析.
- 研究配置障碍和电子转移对晶格氧气稳定和离子氧化还原活性的影响.
主要成果:
- 与传统的NCM-811相比,制造的高度合阴极表现出明显更高的容量和更好的循环稳定性.
- 阴离子高性兴奋剂有效地结氧化晶格氧气,保持高氧含量并触发阴离子氧化还原活性.
- 低电子阴性度的补充剂增强了TM-O八面体中的电子密度,进一步提高了离子氧化还原活性.
结论:
- 低电子负性的阴离子高兴奋剂是一种可行的策略,可以稳定高Ni阴极并解锁阴离子氧化还原.
- 这种方法为合理调整阴极特性和提高LIB性能提供了一条创新的途径.
- 这项研究展示了开发下一代高能量密度电池材料的有希望的方法.
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