Cellulose-based carbon-A potential anode material for lithium-ion battery

A series of hard carbons was produced by the carbonization of microcrystalline cellulose powder in the temperature range of 950-1100 °C. The properties of the carbons were characterized using elemental analysis, X-ray diffraction and N2 and CO2 adsorption. The effect of heat-treatment temperature (HTT), pyrolytic carbon (PC) coating and discharging mode on the lithium insertion/deinsertion behavior of the carbons was assessed in a coin-type half-cell with metal lithium cathode. Increasing cellulose HTT modifies mostly carbon porosity, the surface area (SDFT) decreases from about 500 to 167 m2 g−1. It is associated with lowering the reversible Crev and irreversible Cirr capacities, but without improving relatively low (0.72) 1st cycle coulombic efficiency. Applying constant current (CC)+constant voltage (CV) discharging mode instead of conventional CC enhances the reversible capacity by 15-18%. PC coating is effective in reducing Cirr by ∼20% with a little change of Crev. The best capacity parameters, Crev of 458 mA h g−1 and Cirr of 139 mA h g−1, were measured for PC coated 1000 °C carbon. The prolonged cycling of full-cell assembled with anode of the carbon and commercial cathode revealed that after initial 20 cycles the capacity decay (0.029 mA h/cycle) is comparable to that of commercial cell with graphite-based anode.