CuCo₂S₄ Nanosheets Coupled With Carbon Nanotube Heterostructures for Highly Efficient Capacitive Energy Storage

Abstract

Highly efficient electrode materials with high specific capacitance, good rate capability, and durable cycling stability are of great importance for supercapacitors (SCs). Herein, we report a highly active electrode material based on carbon nanotubes (CNTs) as the supporter and copper cobalt bimetallic sulfide as the active material. The CuCo2S4/CNTs electrode exhibits a good electrochemical performance with a high specific capacity of 1690.3 F g−1 at 1 A g−1, good rate capability with 62.6 % capacitance retention at 50 A g−1, and good cycling stability that retains about 95.5 % of the capacitance after 10 000 cycles. The asymmetric supercapacitors (ACS) are self‐assembled by using CuCo2S4/CNTs as the positive electrode and CNTs as the negative electrode, exhibiting a high energy density of 37.32 Wh kg−1 at a power density of 800.7 W kg−1. This work provides directly empirical evidence for the design and optimization of the supercapacitive performance of transition‐metal compounds.

Supercapacitive Performances of Ternary CuCo2S4 Sulfides

“…As exhibited in Figure (a,b), small CuCo 2 S 4 nanoparticles with size of about 5–20 nm are anchored on the surface of CNTs, and C, N, Cu, Co, and S uniformly distribute throughout the whole structure . Hierarchical CuCo 2 S 4 nanosheets decorated on CNTs were synthesized by a two-step process, and the composite exhibited a specific capacitance of 1690.3 F g –1 at 1 A g –1 …”

“…In order to obtain a wide voltage window, building asymmetric ECs (AECs) is an effective way. Generally, AECs can be classified into two kinds, EDLC//redox ,,,,,,, and redox//redox…”

One‐Pot Synthesis of CuCo2S4 Sub‐Microspheres for High‐Performance Lithium‐/Sodium‐Ion Batteries

“…[12] Yu's group employed a facile in-situ template removal process to receive NiCo 2 S 4 @C hollow nanospheres consisted of ultrathin nanosheets, which achieved a high capacity of 1137 mA h g À 1 for LIBs. [14][15][16][17][18][19][20] Additionally, the merits of high specific capacity, excellent electronic conductivity, rich redox action sites also endowed CuCo 2 S 4 with a promising prospective in application of energy-storage batteries. [14][15][16][17][18][19][20] Additionally, the merits of high specific capacity, excellent electronic conductivity, rich redox action sites also endowed CuCo 2 S 4 with a promising prospective in application of energy-storage batteries.…”

Hydrothermal Synthesis of Cobalt Ruthenium Sulfides as Promising Pseudocapacitor Electrode Materials

“…The XPS survey spectra of the cobalt ruthenium sulfides (Figure 7a) confirmed the presence of Co 2p, Ru 3d, Ru 3p, S 2p, and O 1s states. As shown in Figure 7b, two prominent peaks were observed at binding energies of 778.2 and 793.4 eV corresponding to the Co 2p3/2 and Co 2p1/2 spin-orbit peaks, respectively, which confirmed the existence of two kinds of cobalt oxidation states: Co 2+ and Co 3+ [49,61]. The spin-orbit splitting of Co 2p1/2 and Co 2p3/2 is over 15 eV, suggesting the coexistence of Co 2+ and Co 3+ [62].…”