神东低阶煤基电容炭材料的制备及其电化学性能OA北大核心CSTPCD

To investigate the impacts of specific surface area and micropore pore volume on the electrochemical performance of capacitive carbons derived from low-rank coal,a series of coal-based capacitive carbons were prepared via solid-phase activation by varying the mass ratio of potassium hydroxide(KOH)to Shendong ultra-low ash coal(SLC)(KOH-to-SLC ratio).The composition and pore structure of the capacitive carbon materials were characterized using induc-tive coupled plasma mass spectrometry,ultimate analysis,and nitrogen adsorption/desorption techniques,respectively.The electrochemical performance was assessed through constant cur-rent-discharge tests,cyclic voltammetry(CV),and electrochemical impedance spectroscopy.The results show that as the KOH-to-SLC ratio increases,both the specific surface area and total pore volume of the capacitive carbon materials are enhanced,reaching up to 2736.20 m2/g and 1.296 8 cm2/g,respectively.At a KOH-to-SLC ratio of 2.0∶1,the produced coal-based capaci-tive carbon exhibits a specific surface area of 2 517.80 m2/g and a micropore surface area of 2 485.59 m2/g,which accounted for 98.72%of the total surface area.The micropore pore vol-ume peaked at 0.064 8 cm2/g.Under these conditions,the coal-based capacitive carbon demon-strates a high mass specific capacitance of 173.8 F/g in an organic electrolyte at a current density of 0.05 A/g and maintained a mass specific capacitance of 159.4 F/g at 10 A/g,showing a reten-tion rate of 91.72%.Coal-based capacitive carbon materials has excellent charge-discharge re-versibility and typical double-layer capacitance behavior.