Synthesis Characterization And Properties Of Porous Carbon Anode Materials

Hierarchical porous carbon spheres were prepared by thecarbonization of D201anion-exchange resin. These carbon spheres werecharacterized by X-ray diffraction, Raman spectroscopy, nitrogenadsorption-desorption and electron microscopy. The lithium ion storagecapacity of these carbon spheres was evaluated by galvanostaticmeasurements. The initial discharge/charge capacities of the material are1213and798mAh g^-1at a current density of0.1A g^-1, respectively. Adischarge capacity of506mAh g^-1is still retained when charge-dischargedat1.0A g^-1for50cycles. The large reversible capacity, high rateperformance and good cycleability are attributed to the unique hierarchicalporous structure featured by large surface area, readily accessed porouschannels and the highly graphitized carbon shells. Furthermore, weinvestigated the influence of synthesis conditions on the structure andelectric performance of the materials. The carbonization of cheapanion-exchange resin can be easily scaled-up, making the hierarchicalporous carbon spheres a promising low-cost anode material for highperformance lithium ion batteries.Porous carbon material has been synthesized through an easycarbonization and activation approach by choosing coffee grounds as acarbon source. The prepared carbon material was investigated with X-raydiffraction, scanning electron microscope, Raman spectroscopy and N2adsorption/desorption measurement. The results have demonstrated thatthe carbon material has a disordered structure with relatively highgraphitization degree. The nitrogen adsorption/desorption isotherms and the pore size distribution curve indicate the existence of mesopores. Thedischarge/charge capacities were evaluated by galvanostatic measurements.The initial discharge and charge capacities of the material can reach1029and461mAh g^-1at a current density of0.1A g^-1, respectively, which aremuch higher than the theoretical capacity of graphite (372mAh g^-1). Thecarbonization and activation of cheap coffee grounds can be easilyscaled-up, making the porous carbon a promising low-cost anode materialfor high performance lithium ion batteries.