【摘 要】
：
Rechargeable lithium-oxygen(Li-O2)batteries have appeal to enormous attention because they demon-strate higher energy density than the state-of-the-art Li-ion batteries.Whereas,their practical application is impeded by several challenging problems,such as
【机 构】
：
School of Chemistry and Chemical Engineering,School of Materials Science and Engineering,Hefei Unive
论文部分内容阅读
Rechargeable lithium-oxygen(Li-O2)batteries have appeal to enormous attention because they demon-strate higher energy density than the state-of-the-art Li-ion batteries.Whereas,their practical application is impeded by several challenging problems,such as the low energy round trip efficiencies and the in-sufficient cycle life,due to the cathode passivation caused by the accumulation of discharge products.Developing efficient catalyst for oxygen reduction and evolution reactions is effective to reduce the over-potentials in Li-O2 cells.In our work,we report a Co3O4 modified Ag/g-C3N4 nanocomposite as a bifunc-tional cathode catalyst for Li-O2 cells.The g-C3N4 substrate prevents the accumulation of Ag and Co3O4 nanoparticles and the presence of Ag NPs improves the surface area of g-C3N4 and electronic conduc-tivity,significantly improving the oxygen reduction/evolution capabilities of Co3O4.Due to a synergetic effect,the Ag/g-C3N4/Co3O4 nanocomposite demonstrates a higher catalytic activity than each individual constituent of Co3O4 or Ag/g-C3N4 for the ORR/OER on as catalysts in Li-O2 cells.As a result,the Ag/g-C3N4/Co3O4 composite shows impressive electrochemical performance in a Li-O2 battery,including high discharge capacity,small gap between charge and discharge potential,and high cycling stability.
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