Electrochemical energy storage (EES) devices that combine high-performance are essential to resolve the extreme shortage of non-renewable energy sources and environmental issues. Nickel oxide (NiO) is considered to be a promising EES cathode material because of its ultra-high theoretical specific capacitance, whereas the practical applications are greatly limited with poor rate and cycle performance. Herein, we report the yolk-shelled NiO/Ni composites (YS NiO/Ni) that exhibit good charge storage capability in the aqueous electrolyte with high specific capacitance (2207.3 F g −1 at 1 A g −1 ), exceptional rate capability, and ultra-high cycling stability (95.8% retention after 10,000 cycles). The superior property can be ascribed to the special yolk-shelled structure that exposes more redox reaction active sites, and the associate Ni nanoparticles with flower-like NiO which can improve electron transfer as current collectors.
The decentralized production of H 2 O 2 via a two-electron oxygen reduction reaction (2e − ORR) has emerged as a promising alternative to the energy-intensive anthraquinone (AQ) process. However, its practical application requires 2e − ORR electrocatalysts with high activity and selectivity. Herein, we report the synthesis of metallic Ni nanoparticles anchored on bacterial cellulose-derived carbon fibers (Ni-NPs/BCCF) via a facile impregnation-pyrolysis method as efficient electrocatalysts for 2e − ORR to H 2 O 2 . By tuning the amount of Ni precursor, the best electrocatalytic performance toward 2e − ORR was achieved for Ni-NPs/BCCF-20.7, affording a high H 2 O 2 selectivity of ∼90% and an onset potential of 0.75 V vs. reversible hydrogen electrode (RHE) in an alkaline electrolyte. Ni-NPs/BCCF-20.7 achieved the largest H 2 O 2 yield rate of 162.7 ± 13.7 mmol g cat −1 h −1 and the highest Faradaic efficiency of 93.9% ± 4.2% at 0.2 and 0.5 V vs. RHE from the bulk ORR system, respectively. Theoretical calculations revealed the more favorable “end-on” adsorption configuration of molecular oxygen on the exposed Ni(111) plane, which can effectively suppress the O-O bond dissociation, resulting in high selectivity for H 2 O 2 generation.
Ying Yang,Pengfei Yi,Conghua Zhou,Jiarui Cui,Xiaolu Zheng,Si Xiao,Xueyi Guo,Wenyong Wang
In this work we investigate novel, agarose-based polymer electrolyte that is modified by magnetic NiO nanoparticles for solid-state dye-sensitized solar cells (DSSCs) applications. After proper treatment under an external magnetic field , the agarose electrolyte exhibits increased ionic conductivity and better penetration into the mesoporous TiO 2 photoanode film, which improves the power conversion efficiency of the DSSCs. Electrochemical impedance spectroscopy measurement is also performed to analyze the magnetic field effect on cell performance. After applying proper magnetic filed intensity, the recombination resistance and redox transport resistance in the devices are improved. This method can be possibly applied to other solid-state electrolyte materials to improve their performance and can lead to more efficient DSSCs.
危险品化学品经营许可证（带存储）