Cobalt doped nickel phosphite for high performance of electrochemical energystorage

Bing Li, Yuxin Shi, Kesheng Huang, Mingming Zhao, Jiaqing Qiu, Huaiguo Xue, Huan Pang*

School of Chemistry and Chemical Engineering, Yangzhou University

Abstract:Compared to single metallic Ni or Co phosphides, bimetallic Ni-Co phosphides own ameliorative properties, such as high electrical conductivity, remarkable rate capability, upper specific capacity, and excellent cycle performance. Here, a simple one-step solvothermal process is proposed for the synthesis of bouquet-like cobalt doped nickel phosphite (Ni11(HPO₃)₈(OH)₆), and the effect of the structure on the pseudocapacitive performance is investigated via a series of electrochemical measurements. We found that when the cobalt content is low, glycol/deionized water ratio is 1, reaction under 200^oC for 20 hours, the morphology of the sample is uniform and has the highest specific surface area. The cobalt doped Ni11(HPO₃)₈(OH)₆electrode presented a maximum specific capacitance of 714.8 F g^-1. More significantly, aqueous and solid-state flexible electrochemical energy storage devices were successfully assembled. The aqueous device showed high energy density of 15.48 mWh cm^-2at the power density of 0.6 KW cm^-2. The solid-state device showed high energy density of 14.72 mWh cm^-2at the power density of 0.6 KW cm^-2. These excellent performances confirm that the cobalt doped Ni11(HPO₃)₈(OH)₆are promising materials for applications in electrochemical energy storage device.

Small,2018,201703811.IF = 8.643

文章链接：http://onlinelibrary.wiley.com/doi/10.1002/smll.201703811/full