In situ Raman study of nickel bicarbonate for high-performance energy storage device

By Shuge Dai, Zhuangfei Zhang, Junmin Xu, Weixia Shen, Qiaobao Zhang, Xigui Yang, Tingting Xu, D. Dang, Hao Hu, Bote Zhao and 6 more. Nano Energy, 2019

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Abstract In situ Raman spectroscopy is a powerful technique for probing the structure and phase composition of the electrode materials that are undergoing charge-discharge process. Herein, the charge storage mechanism of as-prepared Ni(HCO3)2 nanomaterial is successfully studied by using the in situ Raman spectroscopy. The charge storage can be attributed to the deep oxidation of Ni2+ into Ni3+, and the irreversible phase transformation of γ-NiOOH into disordered β-Ni(OH)2 damages the crystal structure of Ni(HCO3)2, arousing the capacity loss of the electrode during the long-term cycling process. Under the guidance of the experimental investigations, a porous Ni(HCO3)2/reduced graphene oxide (rGO) nanocomposite is designed and synthesized, exhibiting ultrahigh specific capacity (846 C g−1) and excellent rate capability (618 C g−1 at 20 A g−1). When coupled with an negative electrode based on rGO, the resulting hybrid supercapacitor shows an ultrahigh energy density of 66 Wh kg−1 at power density of 1.9 kW kg−1 and good cycling stability. These findings provide important insight into the mechanism of charge storage, and scientific basis for design of high-performance energy storage materials.

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

View Paper: https://www.semanticscholar.org/paper/daf4d1238183621689aef019c3d555f07aa12276