Preparation of activated carbon from willow leaves and evaluation in electric double-layer capacitors

Activated Carbons and Their Evaluation in Electric Double Layer Capacitors

“…In the recent decade, the preparation of low-cost porous materials from agricultural and industrial waste biomass using ZnCl 2 has been a growing interest. Various precursors, such as cashew nut shell [ 111 ], cherry stones [ 100 , 104 ], Fox nut shell [ 101 ], grape stalk [ 102 ], palm shell [ 112 ], rice husk [ 113 ], sugar cane bagasse [ 114 ], ground coffee [ 99 ], willow leaves [ 115 ], corncob [ 103 ], chestnut shell [ 116 ], peanut shell [ 113 ], oak cups pulp [ 117 ] and hemicellulose [ 118 ] were used for this purpose. The obtained low-cost porous materials are mainly considered as adsorbents for removal of contaminants from water, but also there are attempts to use them as electrode material for supercapacitors [ 113 , 114 , 115 , 116 , 117 , 118 , 119 , 120 ].…”

Evaluación de la capacidad de almacenamiento de energía en xerogeles de carbono activados obtenidos a partir lignina

“…La estructura final de los geles de carbono se obtiene luego del secado (subcrítico, supercrítico o criogénico), y posterior carbonización y/o activación (física o química) con el fin de aumentar el área superficial, y también se pueden incorporar heteroátomos tales como oxígeno, nitrógeno y/o fósforo, que puedan promover efectos pseudocapacitivos originados por propiedades de electrón aceptor/donador [24]. La activación química es la más utilizada debido a que se alcanzan áreas superficiales específicas mayores a 1000m 2 /g donde los agentes activantes más comunes son KOH [25][26][27][28][29], K 2 CO 3 [30][31][32][33], ZnCl 2 [30,34,35] y H 3 PO 4 [30,[36][37][38][39][40][41][42]. El KOH como agente activante tiende a producir una estructura más microporosa con poros anchos, el K 2 CO 3 ha sido utilizado recientemente por ser ambientalmente amigable y seguro, el ZnCl 2 es un agente que tiende un mayor desarrollo mesoporoso y el H 3 PO 4 proporciona una distribución de poros más heterogénea con posibilidad de inclusión de heteroátomos de fósforo y es de fácil recuperación [40,43].…”

Activated Carbon Fibers with Hierarchical Nanostructure Derived from Waste Cotton Gloves as High-Performance Electrodes for Supercapacitors

“…Another class of willow leaf-based APCMs was obtained by Liu et al through ZnCl 2 activation. It also displayed a poor capacitance retention of 70% while increasing the current density from 1 to 5 A g −1 , because its original nanostructure was completely destroyed during the activating process [30]. Thus, carefully selecting a suitable biomass/waste precursor with developed nanostructure and good structural inheritability during the activating process is highly recommended but remains challenging.…”