摘要
Batteries power numerous technolo-gies,yet higher energy density de-mands push lithium cobalt oxide(Li-CoO_(2)referred as LCO)cathodes to higher voltages,triggering unwanted chemical reactions.In this work,we in-vestigate how carbonate-based elec-trolytes degrade on deeply delithiated LCO surfaces via extensive reactive molecular dynamics simulations.These simulations unveil the forma-tion of characteristic gas products and unstable surface species,which can undermine the cathode structure and reduce battery performance.By examining different solvent composi-tions,the simulations reveal that partial fluorination reduces oxidative degradation and gas evolution,thus offering a route to improve interface stability.Overall,this study provides an atomic-level perspective on preventing unwanted reactions and guiding the design of safer and more robust battery systems for high-voltage applications.
电池为众多技术提供动力.现有钴酸锂正极体系在高电压情况下,会发生大量的化学副反应导致产气等安全问题.本文通过长时间反应分子动力学模拟,探究了碳酸酯基电解液在深度脱锂的钴酸锂表面的降解过程;揭示了特征性气体产物和不稳定表面物质的形成过程,并深入分析了正极结构的破坏降低了电池性能的微观机理.模拟结果表明,通过检验不同的溶剂组分,部分氟化可以减少氧化降解和气体析出,为提高界面稳定性提供了新的途径。本研究为抑制钴酸锂正极副反应、指导设计用于高电压应用的更安全、更稳健的电池系统,提供了原子级别的视角和理解.
基金
support from the National Key Research and Development Program of China(No.2022YFB2502200)
the Natural Science Foun-dation of Jiangsu Province(BK20230065)
the Key Laboratory of Functional Nano&Soft Materials,the Collaborative Innovation Center of Suzhou Nano Sci-ence&Technology,the Priority Academic Program Development of Jiangsu Higher Education Institutions(PAPD)
the 111 Project,Joint International Research Laboratory of Carbon-Based Functional Materials and Devices,Yue Liu acknowledges support from the National Natural Science Foundation of China(22303058)
the Natural Science Foundation of Jiangsu Province(BK20230475).
