用于离子电池的高缩性Na缺乏层氧化物
Haoji Wang1, Xu Gao1, Shu Zhang1
1College of Chemistry and Chemical Engineering, Central South University, Changsha 410083, P. R. China.
ACS nano
|June 29, 2023
概括
在Na-deficient层氧化物阴极中进行配置调,通过提高动力学和结构稳定性来提高离子电池的性能. 这种方法解决了缓慢反应和容量退化,以更好地储存能源.
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:
- 在O3结构中,层氧化物面临着缓慢的动力学和高电压 (>4.0V) 的相变化等挑战.
- 这些问题导致了低速率能力和显著的容量退化,限制了它们在电池中的使用.
研究的目的:
- 通过提出配置调节协议来解决层氧化物的局限性.
- 设计缺乏Na的O3型阴极,以提高电化学性能和结构完整性.
主要方法:
- 操纵不活跃的静电比,以创建Na-缺乏,O3型Na0.83Li0.1Ni0.25Co0.2Mn0.15Ti0.15Sn0.15O2-δ (MTS15). 这是一个非常简单的方法.
- 使用理论计算和电化学测量来分析结构和运动性质.
- 采用 ex situ 同步 X 射线吸收光谱和 in situ X 射线衍射来研究氧化还原和相位过渡行为.
主要成果:
- 在MTS15中引入MnO6和TiO6八面体扩大了O-Na-O板块间距,增强了Na+扩散动力学和结构稳定性.
- 热效应提高了氧化还原和O3-P3相位过渡的可逆性.
- 对调整的MTS15阴极显示出显著的速率能力 (76.7%在10°C保持),循环稳定性 (87.2%在200个循环后),以及全细胞性能 (84.3%在100个循环后).
结论:
- 配置调是设计高性能层氧化物的有效策略.
- 开发的MTS15阴极表现出卓越的速率能力,循环稳定性和高功率密度存储系统的空气稳定性.
- 这项工作为为下一代离子电池创造先进材料提供了一种新的方法.
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