Rock salt-type high entropy oxide(Co0.2Cu02Mg0.2Ni0.2Zn0.2)O as anode material for lithium-ion battery has attracted widespread attention due to its unique synergistic effect of multiple elements.Zn and part of Co elements provide the main source of electrode capacities,while MgO stabilizes the crystal structure,Ni,Cu,and the reduced residual Co may form a 3-dimensional network to enhance the conduc-tivities of the oxide.In this study,a series of rock salt-type high entropy oxides(Co0,22Cu0 22Mg0 22Ni0.22Zn0.12)O,(Co0.2Cu0.2Mg0.2Ni0.2Zn0.2)O and(Co0.18Cu0.18Mg0.18Ni0.18Zn0.28)O with different Zn contents were prepared by solution combustion method,while the effect of Zn ion concentration on the electrochemical performance of rock salt-type HEOs was also assessed.The results suggest that with the increasing Zn content,the elec-trochemical performance of the electrode material was enhanced.Although the(Co0.2Cu0.2Mg0.2Ni0.2Zn0.2)O electrode exhibits a higher lattice distortion and oxygen vacancy concentration,resulting in a slightly high-er intrinsic conductivity and lithium ion diffusion coefficient,however,the(Co0.18Cu0.18Mg0.18Ni0.18Zn0.28)O electrode showed the most excellent electrochemical performance with the highest initial discharge spe-cific capacity(777.06 mAh·g-1)and cycling stability(capacity retention rate nearly 100％after 150 cycles)at 200 mA·g-1,as well as excellent rate performance(specific capacity of 140.2 mAh·g-1 at 3000 mA·g-1),and it even shows the best cycling stability after 150 cycles at a high current density of 1000 mAh·g-1(specific capacity of 198.1 mAh·g-1).The excellent electrochemical performance of the(Co0.18Cu0.18Mg0.18-Ni0.18Zn0.28)O electrode may be attributed to the complete conversion of Zn element during the redox reac-tion.The higher Zn content is beneficial to increase capacities,while the appropriate oxygen vacancy con-centration and lattice distortion may provide more channels for Li ion migration,thus resulting in higher cy-cle stability of the electrode.
维普
万方数据