Activated carbons prepared by indirect and direct CO2 activation of lignocellulosic biomass for supercapacitor electrodes

Three-dimensional pore structure of activated carbon monolithic derived from hierarchically bamboo stem for supercapacitor application

“…5(c) shows the specific capacitance for HBP-s samples at different scan rate, and the optimized output was observed with HBP-3a at 147.38 F g -1 (87.31%) and 105.43 F g -1 (62.46%) for scan rate of 2 and 5 mV s -1 , respectively. These results confirms the ability for three-dimensional structures with macropores to provide high amount of accessibility for a specific surface area [16]. However, the values respectively remained at 2.56, 3.64, 55.36, and 18.92 F g -1 for HBP-1a, HBP-1b, HBP-3a and HBP-3b, at the highest rate of 10 mV s -1 .…”

“…This composition is relatively similar to cellulose, while lignin consists of carbon (62 wt%) and oxygen (32 wt%) [15]. Furthermore, the biomass typically includes wood as a major component and grass [16].…”

“…For example, bamboo is a lignocellulosic-based material, comprising about 43.44% cellulose, 29.56% hemicellulose, and 27.52% lignin [17]. This contains a natural porous network, known to support the generation of threedimensional (3D) pore structures [18], and also provide high ion transport [16]. Therefore, bamboo has been suggested as a supercapacitor electrode, and some reports show the fabrication into powder forms, under varied conditions, including temperature of carbonization [19] and activation [18,20], chemical treatment with KOH [18,21,22] or molten carbonate [23], as well as doping with heteroatom (S, N, B) [22,24,25].…”

A Short Review on the Electrochemical Performance of Hierarchical and Nitrogen-Doped Activated Biocarbon-Based Electrodes for Supercapacitors

“…To date, ACs have been the most used electrode materials in SCs due to their easy preparation methods, very high porosity, and SSA, and excellent electrical conductivity [ 34 , 35 , 36 , 37 , 38 , 39 , 40 , 41 , 42 , 43 , 44 ]. Both the biomass precursor and the preparation method are crucial for the ACs properties and greatly influence the final CEs’ electrochemical features (See Table 1 ).…”

“…Jiang et al [ 40 ] converted lignocellulosic biomass into highly porous CEs for SCs. The CE microstructures obtained from direct and indirect activation were highly similar.…”