Abstract
Mn-based layered oxides are among the most promising cathode materials for sodium-ion batteries owing to the advantages of abundance,environmental 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 insufficient Na generally exhibits low initial charge capacity,while O'3 structure with sufficient Na delivers high initial charge capacity but poor cycle stability.This study prepared a multitude of NaxMnO2(x=0.7,0.8,0.9)cathode materials with varying P2/O'3 ratios and further investigated their electrochemical performances.The optimized Na0.8MnO2,comprising 69.9 wt％O'3 and 30.1 wt％P2 phase,exhib-ited relatively balanced specific capacity,Coulombic effi-ciency and cycle stability.Specifically,it achieved a high specific capacity of 128.9 mAh·g-1 with an initial Coulombic efficiency of 98.2％in half-cell configuration.The Na0.8MnO2//hard carbon full cell also achieved a high specific capacity of 126.7 mAh·g-1 with an initial 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 Mn-based layered cathodes.
基金项目
Natural Science Research Project of Anhui Province Education Department(2022AH050334)
Scientific Research Foundation of Anhui University of Technology for Talent Introduction(DT2200001211)
New Energy Electric Vehicles High-Voltage Components Inspection and Testing Public Service Platform()
NETL
NSTL
万方数据