One-step growth of Ni2Co(PO4)2 microspheres for high energy density supercapacitors

Nickel and cobalt phosphates as a kind of low-cost inorganic materials are promising electroactive mate-rials. The structure stability and good dispersibility of micro-spherical materials make them popular in the energy storage field. Therefore, the fabrications of Ni-Co phosphate microspheres with some facile and cost-effective methods have attracted lots of attentions. In this work, we present one-step growth of Ni2Co (PO4)(2) microspheres using urea as pH regulator. Urea decomposes into NH3 and CO2 during the hydro-thermal reaction process, resulting in the precipitation of Ni-Co phosphates. The as-prepared Ni2Co (PO4)(2) microspheres exhibit uniform and well-dispersed spherical morphology. Compared with traditional Ni2Co (PO4)(2) particles, Ni2Co (PO4)(2) microspheres exhibit larger electrochemical specific surface area and smaller resistance of electrons/ions transfer. The specific capacity of Ni2Co (PO4)(2) microspheres reaches as high as 153 mAh g(-1) at a current density of 1 A g(-1), which is 1.59 times higher than that of traditional Ni2Co (PO4)(2) particles. In addition, this facile one-step synthetic method can be applied to fabricate series of Ni-Co phosphates with different Ni/Co atomic ratios. This work provides a facile synthetic method of fabricating Ni-Co phosphate materials, which has potential applications in large-scale manufacture. (c) 2022 Elsevier B.V. All rights reserved.

Automated summary

In this study, Ni2Co(PO4)2 microspheres were synthesized using urea as a pH regulator. The resulting microspheres exhibited uniform and well-dispersed spherical morphology and showed larger electrochemical specific surface area and smaller resistance of electrons/ions transfer compared to traditional particles. The specific capacity of the microspheres reached as high as 153 mAh g(-1), which was 1.59 times higher than that of traditional particles. Additionally, this facile one-step synthetic method could be applied to fabricate Ni-Co phosphates with different Ni/Co atomic ratios.