Dong Hongyu, Tang Panpan, Zhang Shiquan, Xiao Xinglu, Jin Cheng, Gao Yicong, Yin Yanhong, Li Bing, Yang Shuting
College of Chemistry and Chemical Engineering, Henan Normal University Xinxiang 453007 China
National & Local Engineering Laboratory for Motive Power and Key Materials Xinxiang 453000 China
RSC Adv. 2018 Jan 16;8(7):3357-3363. doi: 10.1039/c7ra12630a.
A layered nanosphere structured NiO catalyst was successfully synthesized by a simple and efficient hydrothermal method as a cathode material for lithium-oxygen (Li-O) batteries. Cyclic voltammetry (CV), dual electrode voltammetry (DECV) and chronoamperometry (CA) by rotating ring-disk electrode (RRDE) were carried out to investigate the catalytic activity of this catalyst for the oxygen evolution reaction (OER). The results revealed that the layered nanosphere NiO exhibited excellent electrochemical performance, stability and a typical four-electron reaction as a cathode electrocatalyst for rechargeable nonaqueous Li-O batteries. The overpotential of the NiO is only up to 0.61 V. X-ray photoelectron spectroscopy (XPS) characterization shows that the LiO and LiCO formed during the discharge process and decomposed after charging. Moreover, the cut-off voltage of discharging is about 2.0 V in the NiO-based Li-O batteries, while the specific capacity is up to 3040 mA h g. There is no obvious performance decline of the battery after 50 cycles at a current density of 0.1 mA cm with a superior limited specific capacity of 800 mA h g. Herein, the layered nanosphere structured NiO catalyst is considered a promising cathode electrocatalyst for Li-O batteries.
通过一种简单高效的水热法成功合成了一种层状纳米球结构的NiO催化剂，作为锂氧（Li-O）电池的阴极材料。采用循环伏安法（CV）、双电极伏安法（DECV）和旋转环盘电极（RRDE）计时电流法（CA）来研究该催化剂对析氧反应（OER）的催化活性。结果表明，层状纳米球NiO作为可充电非水Li-O电池的阴极电催化剂表现出优异的电化学性能、稳定性和典型的四电子反应。NiO的过电位仅高达0.61 V。X射线光电子能谱（XPS）表征表明，放电过程中形成的LiO和LiCO在充电后分解。此外，基于NiO的Li-O电池的放电截止电压约为2.0 V，而比容量高达3040 mA h g。在电流密度为0.1 mA cm²下循环50次后，电池性能没有明显下降，具有800 mA h g的优异有限比容量。在此，层状纳米球结构的NiO催化剂被认为是一种有前途的Li-O电池阴极电催化剂。
