Realizing high initial Coulombic efficiency in manganese-based layered oxide cathodes for sodium-ion batteries via P2/O'3 biphasic structure optimization  

作　　者：Bo Peng Zi-Hao Zhou Ping Xuan Jie Xu Lian-Bo Ma 

机构地区：[1]School of Materials Science and Engineering,Anhui University ofTechnology,Ma'anshan 243002,China [2]Anhui Product Quality Supervision&Inspection Research Institute,Hefei 230051,China

出　　处：《Rare Metals》2024年第5期2093-2102,共10页稀有金属（英文版）

基　　金：supported by the Natural Science Research Project of Anhui Province Education Department(No.2022AH050334);the Scientific Research Foundation of Anhui University of Technology for Talent Introduction(No.DT2200001211);the New Energy Electric Vehicles High-Voltage Components Inspection and Testing Public Service Platform。

摘　　要：Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmenta friendliness,low cost and high specific capacity.P2 and O'3 are two representative structures of Mn-based layered oxides.However,the P2 structure containing insufficien Na generally exhibits low initial charge capacity,while O'3structure with sufficient Na delivers high initial charge capacity but poor cycle stability.This study prepared a multitude of Na_(x)MnO_(2)(x=0.7,0.8,0.9)cathode materials with varying P2/O'3 ratios and further investigated their electrochemical performances.The optimized Na_(0.8)MnO_(2) comprising 69.9 wt%O'3 and 30.1 wt%P2 phase,exhibited relatively balanced specific capacity,Coulombic efficiency and cycle stability.Specifically,it achieved a high specific capacity of 128.9 mAh·g^(-1) with an initia Coulombic efficiency of 98.2%in half-cell configuration The Na_(0.8)MnO_(2)//hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g^(-1) with an initia Coulombic efficiency of 98.9%.Moreover,the capacity fading mechanism was revealed by combining in-situ and ex-situ X-ray diffraction.The findings of this study provide theoretical guidance for further modification design of Mnbased layered cathodes.

关 键 词：Sodium-ion batteries Cathode materials Mn-based layered oxides P2/0'3 composites 

分 类 号：TM912[电气工程—电力电子与电力传动]