锂/钠混合离子电池正极材料Na_(2)FePO_(4)F/C的第一性原理研究  

First-principles research on cathode material Na_(2)FePO_(4)F/C for lithium/sodium hybrid ion battery

作　　者：郭容婷 李伟[1] 鲁明峻 吕奕菊[1] 刘峥[1] 艾慧婷 GUO Rong-Ting;Li Wei;LU Ming-Jun;LV Yi-Ju;LIU Zheng;AI Hui-Ting(College of Chemical and Biological Engineering,Guilin University of Technology,Guilin 541004,China)

机构地区：[1]桂林理工大学化学与生物工程学院,桂林541004

出　　处：《原子与分子物理学报》2023年第3期47-53,共7页Journal of Atomic and Molecular Physics

基　　金：国家自然科学基金(52004076);广西自然科学基金面上项目(2020GXNSFAA297054);广西自然科学基金青年基金(2018GXNSFBA281114)。

摘　　要：将锂/钠混合离子电池正极材料Na_(2)FePO_(4)F/C作为研究对象,建立Na_(2)FePO_(4)F、NaFePO_(4)F、NaLiFePO_(4)F、Na_(2)FePO_(4)F/C、NaFePO_(4)F/C、NaLiFePO_(4)F/C的结构模型,并依据第一性原理密度泛函理论,分析了这六种材料的能带、态密度、键长变化以及形成能.研究结果显示,相比于单一的Na_(2)FePO_(4)F,石墨烯包覆的Na_(2)FePO_(4)F的金属特性更良好,电子传输性质更优异,同时具有更加稳定的结构,这表明在电池长时间循环过程中,Na_(2)FePO_(4)F/C晶体结构不容易发生坍塌,容量衰减率更小,这为碳包覆改性制备复合正极材料提供了理论依据.Na_(2)FePO_(4)F/C,lithium/sodium hybrid ion battery cathode material,was taken to work as the research object,and the structure models of Na_(2)FePO_(4)F,NaFePO_(4)F,NaLiFePO_(4)F,Na_(2)FePO_(4)F/C,NaFePO_(4)F/C,NaLiFePO_(4)F/C were established,and their energy bands,densities of state,bond length changes and formation energies were analyzed based on the first-principles density functional theory.It was found that,compared with a bare Na_(2)FePO_(4)F,the graphene-coated Na_(2)FePO_(4)F has better metal properties,better electron transport properties,and a more stable structure,which indicates that the Na_(2)FePO_(4)F/C crystal structure is not prone to collapse during the long-term battery cycle,and the capacity decay rate is smaller.This provides a theoretical basis for the preparation of composite cathode materials by carbon coating modification.

关 键 词：锂/钠混合离子电池 Na_(2)FePO_(4)F 第一性原理 碳包覆 计算化学 

分 类 号：O646[理学—物理化学]