溶解的LiO2还是吸附的LiO2? 在氧电池的放电过程中的活性超氧化物
Chuan Tan1, Wentao Wang1, Yuping Wu2
1State Key Laboratory of Materials-Oriented Chemical Engineering, Nanjing Tech University, Nanjing, Jiangsu, 211816, China. cheny@njtech.edu.cn.
Faraday discussions
|September 27, 2023
概括
氧电池的研究表明,较低的放电潜力会增加副作用和表面被动化. 在电极表面形成的中间体比溶解的更具反应性,影响电池性能.
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:
- 氧 (Li-O2) 电池具有高能量密度,但面临着容量衰减和副作用等挑战.
- 排放潜力的作用与电流密度以及超氧化物中间体的反应性仍然不清楚.
- 标准循环协议经常使用容量切断,导致性能评估中的争议.
研究的目的:
- 研究放电潜力和电流密度对Li-O2电池放电产品和副作用的影响.
- 为了确定溶解或吸附的超氧化物中间体是否更具反应性,并有助于细胞降解.
- 阐明Li-O2电池过早细胞死亡和容量限制背后的机制.
主要方法:
- 分离放电电位和电流密度对放电产品和副作用的影响.
- 使用流细胞设置来区分溶液和表面反应路径.
- 在不同流速下分析排放产品,特别是Li2CO3与Li2O2的比率.
主要成果:
- 电极电位显著影响副作用,较低的电位促进了较高的Li2CO3含量和表面被动化.
- 一个流量电池设置表明,更高的流量 (有利于表面反应) 导致Li2CO3形成的增加.
- 表面吸附的中间体被发现比溶解的中间体更具反应性和攻击性.
结论:
- 放电潜力是影响Li-O2电池中副作用和Li2CO3形成的关键因素.
- 与溶解物种相比,与表面结合的中间体在被动化和性能退化中起着更重要的作用.
- 了解这些机制对于开发更稳定,更高效的氧电池技术至关重要.
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