The Preparation and Electrochemical Pseudocapacitive Performance of Mutual Nickel Phosphide Heterostructures

Autor: Shao-Bo Guo, Wei-Bin Zhang, Ze-Qin Yang, Xu Bao, Lun Zhang, Yao-Wen Guo, Xiong-Wei Han, Jianping Long
Jazyk: angličtina
Rok vydání: 2022
Předmět:
Zdroj: Crystals, Vol 12, Iss 4, p 469 (2022)
Druh dokumentu: article
ISSN: 2073-4352
DOI: 10.3390/cryst12040469
Popis: Transition metal phosphide composite materials have become an excellent choice for use in supercapacitor electrodes due to their excellent conductivity and good catalytic activity. In our study, a series of nickel phosphide heterostructure composites was prepared using a temperature-programmed phosphating method, and their electrochemical performance was tested in 2 mol L−1 KOH electrolyte. Because the interface effect can increase the catalytic active sites and improve the ion transmission, the prepared Ni2P/Ni3P/Ni (Ni/P = 7:3) had a specific capacity of 321 mAh g−1 under 1 A g−1 and the prepared Ni2P/Ni5P4 (Ni/P = 5:4) had a specific capacity of 218 mAh g−1 under 1 A g−1. After the current density was increased from 0.5 A g−1 to 5 A g−1, 76% of the specific capacity was maintained. After 7000 cycles, the capacity retention rate was above 82%. Due to the phase recombination effect, the electrochemical performance of Ni2P/Ni3P/Ni and Ni2P/Ni5P4 was much better than that of single-phase N2P. After assembling the prepared composite and activated carbon into a supercapacitor, the Ni2P/Ni3P/Ni//AC had an energy density of 22 W h kg−1 and a power density of 800 W kg−1 and the Ni2P/Ni5P4//AC had an energy density of 27 W h kg−1 and a power density of 800 W kg−1.
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