在离子电池中,对碳酸盐基溶剂对固体电解质介相形成的还原性分解和结合的添加效应
Keisuke Ushirogata1, Keitaro Sodeyama, Yukihiro Okuno
1Research and Development Management Headquarters, FUJIFILM Corporation, 210 Nakanuma, Minamiashigara, Kanagawa 250-0193, Japan.
Journal of the American Chemical Society
|August 2, 2013
概括
在离子电池电解质中的乙烯碳酸 (VC) 防止乙烯碳酸 (EC) 的分解,增强稳定性. 这种新机制减少了不可逆转的容量,提高了电池的性能.
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
背景情况:
- 固体电解质间相 (SEI) 对离子电池 (LIB) 的稳定性和性能至关重要.
- SEI的形成涉及电解质溶剂分子的还原性分解.
研究的目的:
- 研究乙烯碳酸 (VC) 添加剂对乙烯碳酸 (EC) 在LIB电解质中的溶剂分解的影响.
- 阐明带有和没有VC的SEI形成的热力学和动力学机制.
主要方法:
- 基于密度函数理论 (DFT) 的分子动力学与明确的溶剂.
- 蓝月亮组合技术用于自由能量计算.
- 分析一电子 (1e) 和两电子 (2e) 减少路径,以及离子激素的攻击.
主要成果:
- 该研究准确地复制了实验观察到的气体SEI产品.
- 发现了一种新的机制,其中VC优先与EC离子基发生反应,抑制EC的2e还原.
- 这种虚拟货币介导的途径增强了最初的SEI形成,并且与减少的不可逆转能力相一致.
结论:
- 乙烯碳酸在修改乙烯碳酸分解路径方面发挥着主要作用.
- 这些发现挑战了对风险投资的牺牲性减少的传统观点,提出了一种改善SEI形成的新机制.
- 拟议的机制解释了减少的不可逆转产能,提供了对提高LIB业绩的见解.
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