摘要
通过简单的化学沉积法对正极材料O3型NaNi_(0.5)Mn_(0.5)O_(2)进行MnO_(2)包覆以提高其电化学性能。包覆后的材料相变为P2相。当采用0.5%MnO 2包覆量时,其初始放电比容量由原始相的89.1 mAh·g^(-1)提升到96.4 mAh·g^(-1)。比较倍率性能发现,在5C(1 C=173.4 mA·g^(-1))的大电流密度下具有50 mAh·g^(-1)左右的放电比容量,而原始相接近于0。同时结合循环伏安测试与电化学阻抗测试结果,MnO_(2)包覆能够有效提高材料的可逆性以及抑制表面副产物的生成,从而提高材料的电化学性能。
In this paper,the cathode material O_(3)-NaNi_(0.5)Mn_(0.5)O_(2) was coated with MnO_(2) by chemical deposition method.After coating the material changed from O3 phase to P2 phase.When the coating amount of 0.5% MnO_(2) is used,the initial discharge specific capacity is increased from 89.1 mAh·g^(-1) to 96.4 mAh·g^(-1).It is found that the discharge specific capacity is about 50 mAh·g^(-1) at a high current density of 5 C(1 C=173.4 mA·g^(-1)),while the results of original material is close to 0.Combined with the results of cyclic voltammetry test and electrochemical impedance test,the MnO_(2) coating can effectively improve the reversibility of the material and inhibit the formation of surface by-products,thus improving the electrochemical performance of the material.
作者
陈美丽
袁皓文
孙姝纬
CHEN Meili;YUAN Haowen;SUN Shuwei(School of Physics and Electronics,Henan University,Kaifeng 475004,Henan,China;School of MIAMI,Henan University,Kaifeng 475004,Henan,China)
出处
《化学研究》
CAS
2022年第1期26-31,36,共7页
Chemical Research
基金
科技部“863”项目子课题(2015AA034201)
河南省高层次人才特殊支持中原千人计划(ZYQR201912155)
河南大学一流学科培育项目支持计划(2019YLZDJL03)。
关键词
钠离子电池
层状氧化物
相变
表面修饰
sodium ion battery
layered oxide cathode
phase transition
surface modification
