摘要
Lithium sulfur(Li-S)batteries are poised to be the next generation of high-density energy storage devices.In recent years,the concept of“electrocatalysis”has been introduced into the field of Li-S batteries,and some transition metals have been proved to catalyze the electrochemical conversion reaction of sulfur species.In this study,carbon encapsulated nickel nanoparticles(Ni@C)with a specific surface area of 146 m^(2)/g are shown to play a definitive electrocatalytic role for the sulfur cathode.With Ni@C incorporated,the Ni@C/G-S electrode achieved a better electrochemical performance than the G-S electrode.Moreover,the reversible capacity and cycle stability were further improved through chemical modifications of the carbon shell.The influence of doping with different elements on the Li-S battery performance was also investigated in detail.Higher specific capacities of 1229 mA·h/g,927 mA·h/g,and 830 mA·h/g were achieved at 0.2 C,0.5 C,and 1.0 C for the N-Ni@C-G/S electrode.Besides,the B-Ni@C-G/S electrode possessed a best cycle stability.
基金
This work was financially supported by the China Petrochemical Corporation(218025-9).
