Hierarchitecture Co ₂ (OH) ₃ Cl@FeCo ₂ O ₄ composite as a novel and high‐performance electrode material applied in supercapacitor

Abstract

Summary One‐step hydrothermal reaction has successfully been used to prepared three‐dimensional hierarchitecture Co2(OH)3Cl@FeCo2O4 composite without any annealing treatment. The samples are investigated to confirm the crystal structure, elemental composition, morphology structure and electrochemical performance. The results show the sample has a three‐dimensional hierarchitecture that nanoblocks are assembled with nanoparticles. And the specific surface area is 87.5 m2 g−1 and the total pore volume is 0.17 cm3 g−1. Meanwhile, the composite shows a high specific capacitance of 1110.0 F·g−1 at 1 A·g−1 and great cycling stability with 98.8% capacitance retention after 3000 cycles. To evaluate the electrochemical performances, the results are used to compare with the Co2(OH)3Cl and FeCo2O4 nanomaterials, indicating a higher capacitance and longer cycle stability shown by the as‐synthesized sample. The as‐synthesized Co2(OH)3Cl@FeCo2O4 composite has an outstanding electrochemical performance, predicting an enormous potential and promising future as a novel electrode material applied in supercapacitor.

Advances in Electrochemical and Catalytic Performance of Nanostructured FeCo2O4 and Its Composites

“…This can be explained via the restriction of diffusion of ions due to agglomeration of NF@Co 3 O 4 electrode materials, thereby affecting the progress of electrochemical reactions. Another similar work by Wang et al [68] reports a onestep hydrothermal synthesis (180°C, 21 h) of 3D hierarchical Co 2 (OH) 3 Cl@FeCo 2 O 4 composite (Entry 22, Table 1). However, as an electrode, this material exhibited comparatively lower specific capacitance (1110.0 F g À 1 at 1 A g À 1 ) but excellent cycling stability with 98.8% capacitance retention over 3000 cycles, as shown in Figure 6-h.…”

“…(g) SEM of Co 3 O 4 @ FeCo 2 O 4 core-shell nanoflakes [67]. (h) Plot depicting capacitance retention of 3D hierarchical Co 2 (OH) 3 Cl@FeCo 2 O 4 composite [68]. Reproduced/adapted with permissions from Ref [63]…”

Supercapacitive Performances of Single‐Phase Quaternary Metal Hydroxychlorides

“…Metal hydroxychloride, as a single-phase solid solution, is composed of metal chloride and metal hydroxide, e. g., Mn 2 (OH) 3 Cl and Co 2 (OH) 3 Cl, exhibiting excellent electrochemical performance in lithium-ion batteries, electrocatalytic systems and supercapacitors due to the coexistence of Cl À and OH À in these materials. [13][14][15] For instances, Co 2 (OH) 3 Cl microsphere with the unique lattice structure, as the anode of lithium-ion battery, exhibited the higher rate and better cycle stability relative to CoCl 2 or Co(OH) 2 ; [15] Mn-doped Co 2 (OH) 3 Cl allowed for the higher specific capacitance and better cycling stability compared to the parent metal hydroxychloride, resulted from the greater charge transfer kinetic and the better electric conductivity. [16] This suggests that the controllable introduction of extra metallic components into a single-phase metal hydroxychloride may offer an effective way to improve its pseudocapacitance.…”

Flexible supercapacitors based on mesoporous nanocrystalline cobalt ammonium phosphates and bacterial cellulose composite electrode

“…The advantage for using NH 4 CoPO 4 ·H 2 O as an electrode of a SC is its reversible redox process, high porosity, long life cycles, and excellent electronic conductivity 17 . In general, substrate materials for SCs are expensive Ni foam 11‐18 . Besides, other high‐cost metals are used as substrates, for example, Al foil 19 and Ti foil 20 .…”

“…17 In general, substrate materials for SCs are expensive Ni foam. [11][12][13][14][15][16][17][18] Besides, other high-cost metals are used as substrates, for example, Al foil 19 and Ti foil. 20 Therefore, it is a challenge to develop low-cost, Environmentally-friendly and nonpolluting substrates with flexible, porous structures and high electrolyte capacity.…”