In situ Raman study of nickel bicarbonate for high-performance energy storage device
In situ Raman study of nickel bicarbonate for high-performance energy storage device
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高性能储能装置用碳酸氢镍的原位拉曼研究
DOI：
10.1016/j.nanoen.2019.103919
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发表时间：
2019-10-01
期刊：
影响因子：
17.6
通讯作者：
Liu, Meilin
中科院分区：
文献类型：
--
作者：
Dai, Shuge;Zhang, Zhuangfei;Liu, Meilin
原位拉曼光谱是一种用于探测电极材料在充放电过程中的结构和相组成的强有力的技术。本文利用原位拉曼光谱研究了Ni（HCO 3）（2）纳米材料的电荷储存机理。电荷储存的原因是Ni 2+向Ni 3+的深度氧化，γ-NiOOH向无序β-Ni（OH）（2）的不可逆相变破坏了Ni（HCO 3）（2）的晶体结构，导致电极在长期循环过程中容量损失。在实验研究的指导下，设计并合成了多孔Ni（HCO 3）（2）/还原氧化石墨烯（rGO）纳米复合材料，其比容量为846 Cg（-1），倍率性能为618 Cg（-1）（20 Ag（-1））。当与基于rGO的负极偶联时，所得混合超级电容器在1.9kW kg（-1）的功率密度下显示出66 Wh kg（-1）的储能密度和良好的循环稳定性。这些研究结果为深入了解电荷储存机理提供了重要的理论依据，也为设计高性能储能材料提供了科学依据。
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 asprepared 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 gamma-NiOOH into disordered beta-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 20A 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.