Mushroom-like cobalt nickle metaphosphate@nickel diselenide core-shell nanorods for asymmetric supercapacitors

Ying Xiao; Ge Ye; Mingjiang Xie; Yan Zhang; Jian Chen; Cheng Du; Liu Wan

doi:10.1016/j.jcis.2023.01.141

Mushroom-like cobalt nickle metaphosphate@nickel diselenide core-shell nanorods for asymmetric supercapacitors

J Colloid Interface Sci. 2023 May 15:638:300-312. doi: 10.1016/j.jcis.2023.01.141. Epub 2023 Feb 2.

Authors

Ying Xiao¹, Ge Ye¹, Mingjiang Xie¹, Yan Zhang¹, Jian Chen¹, Cheng Du², Liu Wan³

Affiliations

¹ Hubei Key Lab for Processing and Application of Catalytic Materials, College of Chemical Engineering, Huanggang Normal University, Huanggang 437000, China.
² Hubei Key Lab for Processing and Application of Catalytic Materials, College of Chemical Engineering, Huanggang Normal University, Huanggang 437000, China. Electronic address: ducheng20141020@163.com.
³ Hubei Key Lab for Processing and Application of Catalytic Materials, College of Chemical Engineering, Huanggang Normal University, Huanggang 437000, China. Electronic address: wanliuok2006@163.com.

PMID: 36739748
DOI: 10.1016/j.jcis.2023.01.141

Abstract

Although transition metal metaphosphates (TMPOs) display special physical/chemical features and high theoretical capacities, their applications for supercapacitors (SCs) are still restricted by their low energy densities and inferior cycling stability. Herein, a novel strategy has been proposed to address these issues through in situ construction of cobalt nickle metaphosphate (Co_0.2Ni_0.8(PO₃)₂)@nickel diselenide (NiSe₂) core-shell heterostructure on carbon paper (CP) as a self-supporting flexible electrode for SCs. Particularly, this unique mushroom-like porous nanoarchitecture assembled by one-dimensional (1D) Co_0.2Ni_0.8(PO₃)₂ nanorods and zero-dimensional (0D) NiSe₂ nanospheres can expose abundant active sites and afford multi-dimensional channels, which favors rapid electron ions/electron transfer, accelerates the reaction kinetics, and alleviates volume changes during charging/discharging processes. Profiting from its well-aligned 1D/0D nanostructure and strong synergistic effect between Co_0.2Ni_0.8(PO₃)₂ and NiSe₂, the Co_0.2Ni_0.8(PO₃)₂@NiSe₂/CP electrode delivers a specific capacity of 219.4 mAh/g/0.414 mAh cm^-2 at 1 A/g and good cycling stability with capacity retention of 90.7% after 5000 cycles, outperforming many previously reported TMPO-based electrodes in literature. Impressively, an asymmetric supercapacitor (ASC) device assembled with Co_0.2Ni_0.8(PO₃)₂@NiSe₂ as cathode and porous carbon as anode achieves an energy density of 69.2 Wh kg^-1 at 736.0 W kg^-1 and maintains a capacity retention of 97.6% after 20,000 charge-discharge cycles. This work provides an efficient approach to design multi-dimensional hybrid nanomaterials for high-performance SCs.

Keywords: Asymmetric supercapacitors; Bimetallic metaphosphates; Core-shell structure; Electrodeposition.