摘要
Developing excellent cathode catalysts with superior catalytic activities is essential for the practical application of aprotic lithium-oxygen batteries(LOBs).Herein,we successfully synthesized nitrogen-doped hollow mesoporous carbon spheres encapsulated with molybdenum disulfide(MoS_(2))nanosheets as the cathode catalyst for rechargeable LOBs,and the relationship between the battery performance and structural characteristics was intensively researched.We found that the synergistic effect of the nitrogen-doped mesoporous carbon and MoS_(2)nanosheets endows superior electrocatalytic activities to the composite catalyst.On the one hand,the nitrogen-doped mesoporous carbon could enable fast charge transfer and effectively accommodate more discharging products in the composite skeleton.On the other hand,the thin MoS_(2)nanosheets could promote mass transportation to facilitate the revisable formation and decomposition of the Li2O2 during oxygen reduction reaction and oxygen evolution reaction,and the side reactions were also prevented,apparently due to their full coverage on the composite surfaces.As a result,the catalytic cathode loaded with 2H-MoS_(2)-modified nitrogen-doped hollow mesoporous carbon spheres exhibited excellent electrochemical performance in terms of large discharge-/charge-specific capacities with low overpotentials and extended cycling life,and they hold great promise for acting as the cathode catalyst for high-performance LOBs.
基金
the National Natural Science Foundation of China(grant nos.51971119 and 52171141)
the Natural Science Foundation of Shandong Province(grant nos.ZR2020YQ32 and ZR2020QB122)
the China Postdoctoral Science Foundation(grant no.2020M672054)
the Guangdong Basic and Applied Basic Research Foundation(grant no.2021A1515111124)
the Young Scholars Program of Shandong University(grant no.2019WLJH21).