Flower-like Heterogeneous Phosphorus-Doped Co₃S₄@Ni₃S₄ Nanoparticles as a Binder-free Electrode for Asymmetric All-Solid-State Supercapacitors

Abstract

Through the hydrothermal method and the gas-phase phosphating method, the flower-like heterogeneous phosphorus-doped Co 3 S 4 @Ni 3 S 4 was synthesized in situ on a nickel foam substrate as the binder-free electrode material for supercapacitors. Phosphorus-doped Co 3 S 4 @Ni 3 S 4 electrode material combines the merits of transition metal sulfides and 3D porous network heterostructure, showing the excellent theoretical specific capacitance and the high specific surface area. The introduction of phosphorus atoms with an atomic radius larger than sulfur atoms can optimize the internal electronic structure and cause structural distortion. Therefore, the specific capacitance/specific capacity of this electrode can reach 3614 F g −1 (451 mAh g −1 ) at 1 A g −1 and still maintain the initial specific capacitance of 73% after 3000 cycles. The assembled P−Co 3 S 4 @Ni 3 S 4 -175//AC ASC device exhibits an ultra-high energy density of 72 Wh kg −1 at a power density of 800 W kg −1 . Meanwhile, it can show extraordinary cyclic stability, with a retention rate of 91% after 5000 cycles. This work provides a feasible synthesis method to prepare the composite electrode materials for supercapacitors. KEYWORDS: phosphorus doped, heterogeneous structure, Co 3 S 4 @Ni 3 S 4 nanoparticles, high specific capacitance, asymmetric all-solid-state supercapacitors

Tunable construction of CuS nanosheets@flower-like ZnCo-layered double hydroxide nanostructures for hybrid supercapacitors

“…According to the FE-SEM analysis, it can be concluded that the porous surface of the CS10 nanosheets and flower-like ZC-LDH4 structures after adhering provides stable and appropriate channels to reduce the electrode–electrolyte resistance. 48 As highlighted in the FE-SEM mapping (Fig. S2a–f†), Cu, S, Zn, Co, and O coexisted and were distributed in NF@CS10-ZC-LDH4, which further affirmed the successful fabrication of NF@CS10-ZC-LDH4.…”

“…More significantly, the nanoflowers of NF@CS10-ZnCo-LDH4 were more compact in structure than those of NF@CS10-ZC-LDH2, which not only accelerates charge transfer and ion diffusion but also efficiently provides additional reaction sites to significantly improve the electrical activities of NF@CS10-ZC-LDH4. 48…”

“…significantly improve the electrical activities of NF@CS10-ZC-LDH4. 48 CS10-ZC-LDH6 showed uniformly grown spherical-like structures throughout the NF (Fig. 2i).…”

Low-Temperature Solvothermal Growth of CoxSy Nanospheres on Conducting Substrates as Efficient Electrodes for Hydrogen Evolution Reaction

“…From the TEM images, it is evident that the Co x S y nanospheres consist of hierarchical structures with an outer layer of interlaced nanosheets with a curved architecture. The evolution of such hierarchical spheres comprising ultrathin nanosheets has been widely reported for the solvothermal synthesis of Co 9 S 8 and Co 3 S 4 . – …”

Rich-grain-boundary Ni–Co–Se nanowire arrays for fast charge storage in alkaline electrolyte

“…Till now, the Se-doped Ni/Co compounds appeared to be the good electrode materials for the new generation supercapacitors. Besides, the creation of structural defects as well as the high-density grain boundaries have also been recognized as an effective approach to enhance the energy density by making more surface active sites available [17][18][19]. Contributed by the looser structures, the diffusion of atoms always tends to be faster along grain boundaries than through the lattices, and more specifically, the grain boundary diffusion coefficient has been reported to be several orders of the bulk diffusion coefficient.…”