A space-sacrificed pyrolysis strategy for boron-doped carbon spheres with high supercapacitor performance

Biomass-derived carbon materials for vanadium redox flow battery: From structure to property

Biomass-derived carbon (BDC) materials are suitable as electrode or catalyst materials for vanadium redox flow battery (VRFB), owing to the characteristics of vast material sources, environmental friendliness, and multifarious structures. A timely and comprehensive review of the structure and property significantly facilitates the development of BDC materials. Here, the paper starts with the preparation of biomass materials, including carbonization and activation. It is designed to summarize the lastest developments in BDC materials of VRFB in four different structural dimensions from zero dimension (0D) to three dimension (3D). Every dimension begins with meticulously selected examples to introduce the structural characteristics of materials and then illustrates the improved performance of the VRFB due to the structure. Simultaneously, challenges, solutions, and prospects are indicated for the further development of BDC materials. Overall, this review will help researchers select excellent strategies for the fabrication of BDC materials, thereby facilitating the use of BDC materials in VRFB design.

Wrinkled Hollow Carbon Spheres with Adjustable Diameter for High-Performance Supercapacitors

Creating more pleated and collapsed structures for carbon-based electrode materials is an important measure to enhance the performance of supercapacitors. Herein, a polymer formed by the aldimine reaction of terephthalaldehyde and aminopropyltriethoxysilane was utilized as the carbon source, and tetraethoxysilane was added as a silica additive to achieve the wrinkled structure on hollow carbon spheres. The silica had a significant modulating effect on the structure of the obtained wrinkled hollow carbon sphere (WHCS), which displayed a visible pleated structure, hollow structure, high specific surface area, and pore volume. As an electrode material for supercapacitors, WHCS exhibits excellent performance with a capacitance of 312 F ⋅ g-1 and remarkable cycle life stability, demonstrating its great potential for use in supercapacitors.

Multi-element co-doped biomass porous carbon with uniform cellular pores as a supercapacitor electrode material to realise high value-added utilisation of agricultural waste

Biomass-based porous carbon materials have attracted considerable attention because of their simple, low-cost, green, and pollution-free preparation process. Owing to their unique tubular structure and subsequent activation process, they often have a well-developed pore structure. Biomass-based carbon materials with three-dimensional hierarchical pores and polyatomic doping are regarded as promising electrode materials in the field of energy storage. In this study, cornstalk was used as the biomass and a pioneering approach was used to prepare porous carbon co-doped with N, B, and P. The B,N,P-codoped porous carbon has a three-dimensional honeycomb-like network structure with uniformly distributed and interwoven macro-, meso-, and micropores. Furthermore, it has an ultra-high specific surface area of 3123.5 m² g^-1, a high specific capacitance of 342.5 F g^-1 at a current density of 0.5 A g^-1, and an energy density of up to 26.18 W h kg^-1. This study demonstrates a multi-element co-doping strategy that enhances the performance of cornstalk as a precursor of a supercapacitor electrode material and has important implications in the high-value-added utilisation of waste straw.