Toward Highly Efficient Electrocatalyst for Li–O2 Batteries Using Biphasic N‑Doping Cobalt@Graphene Multiple-Capsule Heterostructures

• Published in: Nano letters 2017-05, Vol.17 (5), p.2959-2966
• Main Authors: Tan, Guoqiang, Chong, Lina, Amine, Rachid, Lu, Jun, Liu, Cong, Yuan, Yifei, Wen, Jianguo, He, Kun, Bi, Xuanxuan, Guo, Yuanyuan, Wang, Hsien-Hau, Shahbazian-Yassar, Reza, Al Hallaj, Said, Miller, Dean J, Liu, Dijia, Amine, Khalil
• Format: Article
• Language: English
• Subjects: cathode catalyst; cobalt nitride; ENERGY STORAGE; INORGANIC, ORGANIC, PHYSICAL, AND ANALYTICAL CHEMISTRY; lithium-oxygen battery; MATERIALS SCIENCE; MOF; N-doped graphene
• ISSN: 1530-6984; 1530-6992
• DOI: 10.1021/acs.nanolett.7b00207

For the promotion of lithium–oxygen batteries available for practical applications, the development of advanced cathode catalysts with low-cost, high activity, and stable structural properties is demanded. Such development is rooted on certain intelligent catalyst-electrode design that fundamentally facilitates electronic and ionic transport and improves oxygen diffusivity in a porous environment. Here we design a biphasic nitrogen-doped cobalt@graphene multiple-capsule heterostructure, combined with a flexible, stable porous electrode architecture, and apply it as promising cathodes for lithium–oxygen cells. The biphasic nitrogen-doping feature improves the electric conductivity and catalytic activity; the multiple-nanocapsule configuration makes high/uniform electroactive zones possible; furthermore, the colander-like porous electrode facilitates the oxygen diffusion, catalytic reaction, and stable deposition of discharge products. As a result, the electrode exhibits much improved electrocatalytic properties associated with unique morphologies of electrochemically grown lithium peroxides.