Two-dimensional porous cobalt–nickel tungstate thin sheets for high performance supercapattery

By Biao Huang, Huayu Wang, Shunfei Liang, Huizhen Qin, Yang Li, Ziyang Luo, Chenglan Zhao, Li Xie, Lingyun Chen. 2020

222 citations recorded by the source corpus.

Abstract In order to meet the increasing demand for electric energy, it is of great significance to develop high-performance electrochemical energy storage materials. Cobalt/nickel-based tungstates (MWO4, M ​= ​Co, Ni and Co–Ni) show much higher electrical conductivity than pure oxides. However, due to their relatively low capacity and poor cycle stability, their potential as electrode materials for high-performance supercapatteries is limited to a great extent. In this paper, we reported the successful synthesis of bimetallic two-dimensional (2D) Co–Ni tungstates thin sheets assembled by nanosheets through a substrate-free hydrothermal method. The ratio of Co/Ni was optimized to 1:1 and the as-obtained Co0.5Ni0.5WO4 (CNWO) electrode exhibited a high specific capacity of 626.4 ​C ​g−1 ​at 1 ​A ​g−1 and high cyclic stability (105.3% capacity maintained over 10,000 cycles at 10 ​A ​g−1) in a three-electrode system, which is attributed to the synergistic effect of 2D/3D porous architecture and bimetallic composition of CNWO. An alkaline hybrid supercapattery (CNWO//activated carbon(AC)) with CNWO as the positive electrode and AC as the negative one showed the maximum specific energy of 42.2 ​Wh·kg−1 ​at the specific power of 1047.7 ​W ​kg−1 with a long cycle life (93.5% capacity retention after 15,000 cycles at 10 ​A ​g−1). The rational design of CNWO could pave the way for the preparation of bimetallic oxides with significantly improved electrochemical property.

Subfields: Electrical and Electronic Engineering, Electronic, Optical and Magnetic Materials

View Paper: https://www.semanticscholar.org/paper/e0b0d9084a4ceb1efb16df2af4e47d9b76861bee