• 文献标题:   Co-Ni Alloy Encapsulated by N-doped Graphene as a Cathode Catalyst for Rechargeable Hybrid Li-Air Batteries
  • 文献类型:   Article
  • 作  者:   CHANG Z, YU F, LIU ZC, PENG S, GUAN M, SHEN XX, ZHAO SL, LIU N, WU YP, CHEN YH
  • 作者关键词:   bifunctional catalyst, ndoped graphene encapsulation, hybrid liair battery
  • 出版物名称:   ACS APPLIED MATERIALS INTERFACES
  • ISSN:   1944-8244 EI 1944-8252
  • 通讯作者地址:   Nanjing Tech Univ
  • 被引频次:   7
  • DOI:   10.1021/acsami.9b12213
  • 出版年:   2020

▎ 摘  要

A hybrid Li-air battery uses a protected lithium anode and a porous air cathode in an aqueous electrolyte, based on a 4-e oxygen reduction reaction/oxygen evolution reaction (ORR/OER). It avoids the insoluble and insulating Li2O2 product in a typical nonaqueous Li-air battery, and it owns unique advantages. A bifunctional cathode catalyst is crucial to battery performance. Here, we synthesize an ultrathin N-doped graphene-encapsulated nanosphere Co-Ni alloy (Co-Ni@NG). It has hierarchical architecture consisting of a uniform Co-Ni nanoalloy coated with a thin layer of N-doped graphene, showing high activity, high stability, and lower overpotential between the ORR and OER (0.55 V between onset potentials). It exhibited a discharge/charge voltage gap of 0.55 V at a current density of 1.4 mA cm(-2), which is much smaller than the commercial Pt/C catalyst. It delivered an energy density of 3158 Wh kg(-1) and a power density as high as 134.2 W m(-2) at a current density of 7 mA cm(-2). The graphene shells protect the alloy catalyst and improve the durability of the catalyst. One hundred cycles were demonstrated without significant deterioration. It was testified as a promising energy storage system with high energy density, efficiency, reliability, and durability.