Composites of sodium manganese oxides with enhanced electrochemical performance for sodium-ion batteries: Tailoring properties via controlling microstructure

作     者：HUANG JiaJia LUO Jian 

作者机构：Department of Nano Engineering Program of Materials Science and Engineering University of California 

出 版 物：《Science China(Technological Sciences)》 (中国科学（技术科学英文版）)

年 卷 期：2016年第59卷第7期

页      面：1042-1047页

核心收录：

学科分类：0808[工学-电气工程] 08[工学] 0805[工学-材料科学与工程（可授工学、理学学位）] 080502[工学-材料学] 

基　　金：supported by the U.S.NSF(Grant No.DMR-1320615) subsequently an NSSEFF fellowship(Grant No.N00014-15-1-0030) 

主　　题：sodium ion battery cathode material composite electrode microstructure morphology 

摘      要：Composites of Na_(0.44)Mn O_2, Na_(0.7)Mn O_(2.05), and Na_(0.91) Mn O_2 were synthesized by facile solid-state reaction, ball milling, and annealing methods. Two different composites of identical overall composition but drastically different morphologies and microstructures were synthesized. A composite of a hierarchical porous microstructure with primary and secondary particles(i.e., a meatball-like microstructure) achieved an excellent stable capacity of 126 m A h g^(-1) after 100 cycles. The rate capability of the composite could be dramatically enhanced by another round of high-energy ball milling and reannealing; subsequently, a composite that was made up of irregular rods was obtained, for which the capacity was improved by more than 230% to achieve ~53 m A h g^(-1) at a particularly high discharge rate of 50 C. This study demonstrated the feasibility of tailoring the electrochemical performance of electrode materials by simply changing their microstructures via facile ball milling and heat treatments, which can be particularly useful for optimizing composite electrodes for sodium-ion batteries.