Self-templating Scheme for the Synthesis of Nanostructured Transition-Metal Chalcogenide Electrodes for Capacitive Energy Storage

Abstract

Due to their unique structural features including well-defined interior voids, low density, low coefficients of thermal expansion, large surface area and surface permeability, hollow micro/nanostructured transition metal sulfides with high conductivity have been investigated as new class of electrode materials for pseudocapacitor applications. Herein, we report a novel self-templating strategy to fabricate well-defined single and double-shell NiCo 2 S 4 hollow spheres, as a promising electrode material for pseudocapacitors. The surfaces of the NiCo 2 S 4 hollow spheres consist of self-assembled 2D mesoporous nanosheets. This unique morphology results in a high specific capacitance (1263 F g -1 at 2 A g -1 ), remarkable rate performance (75.3% retention of initial capacitance from 2 A g -1 to 60 A g -1 ) and exceptional reversibility with a cycling efficiency of 93.8% and 87% after 10,000 and 20,000 cycles, respectively, at a high current density of 10 A g -1 . The cycling stability of our ternary chalcogenides is comparable to carbonaceous electrode materials, but with much higher specific capacitance (higher than any previously reported ternary chalcogenide), suggesting that these unique chalcogenide structures have potential application in next-generation commercial pseudocapacitors.

Hierarchical Structures Based on Two‐Dimensional Nanomaterials for Rechargeable Lithium Batteries

“…This type of hierarchical structure is so far applicable to many TMOs/TMDs with various shapes, such as Fe 3 O 4 hollow sphere, [71] TiO 2 hollow tubular, [72] MoS 2 hollow tubular, [73] MoS 2 hollow box. Apart from the TMOs/TMDs, some hollow structured polynary TMOs/TMDs (e.g., CoMn 2 O 4 hollow sphere, [79] Graphene-encapsulated ZnNiCoO microsphere, [80] M-Mn based oxides hollow tubular, [81] core-shelled NiCo 2 O 4 hollow sphere, [82] multi-shelled NiCo 2 S 4 hollow sphere [83] ) were also attractive electrode materials for LIBs and Li-O 2 batteries and etc. It is worth reminding that the excess empty space greatly reduces tap density, resulting in low volumetric energy and power density of electrode fabricated from these single-shelled materials.…”

Development of a hollow carbon sphere absorber displaying the multiple-reflection effect to attenuate electromagnetic waves

“…24 In a typical synthesis process, 50 mg of silica particles with an average diameter of~200 nm and 2 mL of ammonia were added into a mixture containing 4 mL TEOS, 24 mL of distilled water, and 60 mL absolute ethanol. The resulting mixture was magnetically stirred at room temperature for 2 h, and the products of this stirring were washed and dried in air.…”

Mixed Metal Sulfides for Electrochemical Energy Storage and Conversion

“…In general, a self-template method involves the synthesis of template precursors and subsequent sulfidation treatment process through ion-exchange reactions and/or Kirkendall effect. Up to present, numerous intriguing templates have been developed, including mixed metal oxide, [72,73] mixed metal hydroxide, [74,75] layered double hydroxide (LDH), [76,77] mixed metal carbonate, [78,79] mixed metal glycerate, [28,80,81] mixed metal carbonate hydroxide, [27,82] mixed metal acetate hydroxide, [83] mixed metal silicate, [84,85] and metal-organic frameworks (MOFs). [86][87][88] These self-engaged templates could directly determine the shape, size, and composition of the resultant MMSs.…”