钠离子电池正极材料P2-Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2)的电化学活性研究  

Electrochemical Activity of Positive Electrode Material of P2-Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2) Sodium Ion Battery

作　　者：张晓君 李佳乐 邱吴劼 杨淼森 刘建军[2,3,4] ZHANG Xiaojun;LI Jiale;QIU Wujie;YANG Miaosen;LIU Jianjun(Jilin Province Sci-Tech Center for Clean Conversion and High-valued Utilization of Biomass,Northeast Electric Power University,Jilin 132012,China;State Key Laboratory of High Performance Ceramics and Superfine Microstructure,Shanghai Institute of Ceramics,Chinese Academy of Sciences,Shanghai 200050,China;Center of Materials Science and Optoelectronics Engineering,University of Chinese Academy of Sciences,Beijing 100049,China;School of Chemistry and Materials Science,Hangzhou Institute for Advanced Study,University of Chinese Academy of Sciences,Hangzhou 310024,China)

机构地区：[1]东北电力大学吉林省生物质清洁转化与高值化利用科技创新中心,吉林132012 [2]中国科学院上海硅酸盐研究所,高性能陶瓷和超微结构国家重点实验室,上海200050 [3]中国科学院大学材料科学与光电工程中心,北京100049 [4]中国科学院大学杭州高等研究院,化学与材料科学学院,杭州310024

出　　处：《无机材料学报》2021年第6期623-628,共6页Journal of Inorganic Materials

基　　金：国家自然科学基金(21973107,11804351);吉林省教育厅项目(JJKH20190693KJ)。

摘　　要：钠离子电池具有成本低廉、原料分布广泛等优点,是锂离子电池正极材料的最佳替代材料。在具有层状结构的P2相NaMnO_(2)正极材料中,对过渡金属层进行二元固溶可有效提升电极材料的电化学性能。本研究利用库仑模型构建了Mg离子固溶的Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2)结构模型。通过第一性原理计算发现,在钠离子含量小于0.67时,Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2)的放电电压达到3.0 V。电子态密度和电荷布居分析共同表明,Mg的固溶激活了P_(2)相Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2)中晶格氧的电化学活性,使体系的电化学反应机制从阴阳离子协同电化学反应转变为可逆阴离子电化学反应。这一机理为钠离子电池电极材料的设计提供了一种全新方法,也为其它离子电池的优化和探索提供了全新的思路。With the advantages of low cost and wide distribution of raw materials,sodium-ion batteries are considered to be the best alternative materials for lithium-ion battery cathode materials.In the P2-phase NaMnO_(2) with layered structure,binary solid solution of the transition metal layer can effectively improve the electrochemical performance of the electrode material.In this study,the structural model of Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2) with Mg ion solid solution was constructed by using the Coulombic model.The first-principles calculations revealed that discharge voltage of Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2) reached 3.0V at a sodium ion content of less than 0.67.Electronic density of states and charge population analysis showed that the solid solution of Mg motivated the anionic electrochemical activity of lattice oxygen in the P2-phase Na_(x)[Mg_(0.33)Mn_(0.67)]O_(2),which transformed the electrochemical reaction mechanism of the system from cationic and anionic synergic redox reaction to reversible anionic redox reaction.This transformation provides a novel method for the design of electrode materials for Na ion batteries,as well as a new approach for the optimization and exploration of other ion batteries.

关 键 词：钠离子电池 电化学活性 第一性原理 碱金属掺杂 

分 类 号：O646[理学—物理化学]