Facile deposition of binder-free Co₃O₄/KB cathode for low overpotential Li-O₂ battery

Dan Zhang, Baoqi Wang, Mi Yan, Yinzhu Jiang*

State Key Laboratory of Silicon Materials, Key Laboratory of Advanced Materials and Applications for Batteries of Zhejiang Province and Department of Materials Science and Engineering, Zhejiang University, Hangzhou, Zhejiang 310027, China E-mail: yzjiang@zju.edu.cn (Y. Jiang)

Co₃O₄ is a promising candidate as bi-functional catalyst for oxygen reduction reaction and oxygen evolution reaction in Li-O₂ batteries. However, the poor electrical conductivity limited by its nature as metal oxide impairs its electrochemical performance, as well as the poor attachment to the current collector originated from the traditional slurry coating process. To overcome these problems, we develop a facile route to prepare Co₃O₄/KB cathodes on nickel foam by electrostatic spay deposition in one step. The as-deposited Co₃O₄/KB composite cathode demonstrates extremely excellent catalytic activity toward oxygen evolution reaction. A significantly reduced charge potential (3.32 V) than that of the pristine KB (3.87 V) cathode is achieved. More importantly, a superior cycling stability is observed in electrochemical tests by restricting discharge depth to 500 mAh g^-1 at 0.2 mA cm^-2. The admirable electrochemical performance is owed to enhanced electrical conductivity, steady adherence to nickel foam and homogeneously dispersed Co₃O₄ among KB conductive agent. The preliminary results indicate that the present Co₃O₄/KB composite cathode is an efficient and stable catalyst for Li-O₂ battery. The one-step electrostatic spray deposition technique offers a facile and effective route for the preparation of Li-O₂ cathodes.

Presenter: Yinzhu Jiang (Ph. D., Asso. Prof., Zhejiang University)