Self-Sacrificing Template-Derived Hollow-Structured NiCo₂S₄ Spheres with Highly Efficient Supercapacitance Performance

Abstract

Highly efficient supercapacitance performance requires electrode materials to have large electrochemical reaction interfaces due to the surface reaction properties. In this work, a hollow-structured NiCo2S4 spinel is synthesized via an in situ preparation strategy. First, NiCo-glycolate solid spheres are obtained via a simple solvothermal method. The hollow structure is formed through a liquid sulfidation approach using NiCo-glycolate solid spheres as a self-sacrificing template, according to the Kirkendall effect. NiCo2S4 with hollow-structured spheres as supercapacitor electrodes exhibits an excellent specific capacitance of 1387.5 F·g–1 at 1 A·g–1 and a highly efficient cycling stability for over 4500 cycles. Moreover, when served as an all-solid-state asymmetric supercapacitor electrode, superior energy density (39 Wh·kg–1) is achieved at the power density of 215 W·kg–1. The superior energy storage performance is ascribed to the unique properties of the NiCo2S4 spinel, the mesoporous structure, and the large hollow space for alleviating the structure strain.

Yolk–Shell Structured Nickel Cobalt Sulfide and Carbon Nanotube Composite for High-Performance Hybrid Supercapacitors

“…38 The GCD curves of the NCS/CNT-2 electrode are shown in Figure 4e, the voltage is 0−0.4 V. According to eq 2, the calculated specific capacities at 1, 2, 4, 8, 10, and 15 A g −1 are 603, 560, 508, 459.6, 442, and 406.5 C g −1 , respectively. Precisely, the NCS/CNT-2 composite exhibited that the electrochemical performance is better than that of the other reported data listed in Table S1, such as NiCo 2 S 4 @Ni 3 V 2 O 8 core/shell architecture, 39 hollow-structured NiCo 2 S 4 spheres, 40 NiCo 2 S 4 NSs/P-g-C 3 N 4, 41 MXene-NiCo 2 S 4 @NF, 42 NiCo 2 S 4 nanoflowers, 43 and NiCo 2 S 4 ball-in-ball hollow spheres. 5 As shown in Figure 4f, when the charge and discharge current density increases from 1 to 15 A g −1 , the electrode constructed by NCS/CNT-2 can retain 67.4% of the initial capacitance, which is higher than that of NCS (53%), NCS/ CNT-1 (56.2%), and NCS/CNT-3 (64.5%).…”

“…The GCD curves of the NCS/CNT-2 electrode are shown in Figure e, the voltage is 0–0.4 V. According to eq , the calculated specific capacities at 1, 2, 4, 8, 10, and 15 A g –1 are 603, 560, 508, 459.6, 442, and 406.5 C g –1 , respectively. Precisely, the NCS/CNT-2 composite exhibited that the electrochemical performance is better than that of the other reported data listed in Table S1, such as NiCo 2 S 4 @Ni 3 V 2 O 8 core/shell architecture, hollow-structured NiCo 2 S 4 spheres, NiCo 2 S 4 NSs/P-g-C 3 N 4, MXene-NiCo 2 S 4 @NF, NiCo 2 S 4 nanoflowers, and NiCo 2 S 4 ball-in-ball hollow spheres …”

Synthesis and Applications of Nanostructured Hollow Transition Metal Chalcogenides

“…MIBs [192] Fe 7 S 8 /C@d-MoS 2 Hollow nanocages 505 mAh g −1 at 0.5 A g −1 , 318 mAh g −1 at 5 A g −1 286 mAh g −1 at 4 A g −1 , 500 cycles PIBs [127] SnS 2 @C Hollow nanobox 508 mAh g −1 at 0.1 A g −1 , 222 mAh g −1 at 2 A g −1 347 mAh g −1 at 1 A g −1 , 300 cycles 72% capacity retention PIBs [134] N-CoS 2 Yolk-shell nanospheres 744 mAh gZn −1 at 5 mA cm −2 165 h at 10 mA cm −2 ZABs [193] NiCo 2 S 4 Hollow spheres 1387.4 F g −1 at 1 A g −1 , 755 F g −1 at 10 A g −1 1387.5 F g −1 at 1 A g −1 , 4500 cycles 92.2% capacity retention SCs [194] For example, a semiconductor photocatalyst condenses electrons on the catalyst surface, thereby improving the photocatalytic CO 2 reduction ability. [69] Therefore, the preparation of some new-type, good-effect, and environment friendly photocatalysts has aroused great interest from many researchers.…”

“…Among them, supercapacitors (SCs) and batteries are used as energy storage components and are part of the energy storage system. [ 194 ] HTMC has attracted much attention due to its superior energy storage capacity for rechargeable batteries. Compared with nonhollow TMC materials, HTMC has a larger surface area, lower energy density, and can effectively alleviate the volume expansion caused by the battery during charge and discharge.…”

Realizing high performance flexible supercapacitors by electrode modification

“…[13][14][15] Compared with single metal suldes, mixed metal suldes show rich redox reactions, which signicantly improve the electrochemical performance of the device. [16][17][18] However, the brittle feature of transition metal suldes means they tend to collapse during long-term cycling, which further hinders their practical application. [19][20][21] Hybrid electrode structures formed by combining suldes and other electrode materials are considered as a feasible way to improve the electrochemical performance.…”