![]() ![]() prepared activated carbon fiber by using CO 2 activation in the presentation of nickel. The obtained porous carbon shown high selective adsorption property for CO 2 with a capacity of 4.4 mmol g −1. introduced a trace amount of calcium-containing additive into the coal framework for the synthesis of porous carbons. By using a small amount of catalysts, the catalytically physical activation strategy offers a new way to modify the pore structure of coal-based activated carbons. It is still of interest to further improve the electrochemical properties of ACs based on steam activation.Īccording to the previous study, transition metals and alkaline earth metals species could adjust the formation of pore structure in ACs. The sugarcane leaves derived activated carbons assembled in coin had the highest specific capacitance of around 16 F g −1 in organic electrolyte. used sugarcane leaves activated at 800 ☌ to produce electrode materials for supercapacitors. prepared electrode materials derived from phenolic formaldehyde resin for electric double-layer capacitors by steam activation at 900 ☌ and showed the capacitance of 106.5 F g −1 at 50 mA g −1 in the organic system. The products obtained through steam activation typically have low specific surface areas (<1100 m 2 g −1) and are unable to meet the growing demand for ECs. However, the activation reactions occur at the interface between oxidizing gases and the carbon matrix. In the activation process, steam is used as an oxidizing gas to react with carbon at temperatures between 8 ☌ to form porous structures. In contrast, steam activation is a cleaner method of activation in industries. However, the strong basicity of KOH will cause severe corrosion to devices and expose the overloaded pollutants to the environment during the activation process. For example, chemical activation usually employs KOH as activation agent, because it can activate ACs with high specific surface areas (>3000 m 2 g −1) and well-developed pore structures. ĭespite the fact that physical and chemical activation have been extensively used for the production of ACs, there are still many limitations resulting from the intrinsic reaction characteristics between the carbon matrix and activation agents. For coal or biomass to be converted to ACs, traditional activation techniques such as physical or chemical activation are still the best options. However, these methods are not well suitable for compact and complex carbon precursors. For the aim of engineering the porous structure of ACs, many synthetic methods such as hydrothermal carbonization, self-assembly, and soft/hard template have been adopted. In order to achieve high energy storage performance with ECs, ACs must have a large surface area, well-developed porosity, and outstanding stability. Among multitudinous electrode materials, activated carbons (ACs) are widely employed as electrode materials for ECs due to their low cost, sufficient resources, and easy industrial production. ![]() This work not only provides the mechanism understanding of the KOH-induced catalytic activation but also proves that the trace KOH-induced catalytic activation is a viable and green method for developing high-performance activated carbons for the demand of ECs in industrial applications.ĭue to the merits of ultrafast charge rate, remarkable power density, and prolonged cycling performance, ECs have been widely employed in many industrial areas. ![]() Evaluated as electrochemical capacitor (EC) electrode material, the obtained sample achieves a high specific capacitance of 157.5 F g −1 at a current density of 1 A g −1 and shows an excellent cycling performance with 97 % retention over 10,000 cycles at 2 A g −1. As the result, the obtained sample has a high specific surface area of 958 m 2 g −1 and a total volume of 0.448 cm 3 g −1. Furthermore, trace KOH can enlarge the specific surface areas and change the surface functionalities of ACs. By studying the pore formation, trace KOH is found to be associated with mesopore formation and promotes the development of micropores in ACs, regulating the hierarchical structure of pores. With the aim of more efficiently using oaks resources, this study proposed a green and efficient strategy of trace KOH-induced catalytic activation to generate oaks-derived activated carbons (AC) for electrochemical capacitor applications. ![]()
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