National Research Council of Canada. Energy, Mining and Environment
Amorphous carbon; Cathodes; Electric discharges; Electrodes; Graphene; Liquids; Lithium; Lithium compounds; Lithium-ion batteries; Low temperature effects; Nanotechnology; Temperature; Discharge capacities; Electrochemical performance; Electrochemical test; Graphene oxides; Liquid-phase method; Liquid-phase synthesis; Lithium iron phosphates; Low temperature synthesis; Lithium alloys
Nano-scale LiFePO<inf>4</inf>/graphene oxide (GO) as cathode materials for lithium ion batteries has been successfully synthesized via a one-step carbon gel assisted liquid-phase approach at a low-temperature (108 °C) and normal pressure. C-LiFePO<inf>4</inf>/graphene layers (G) composites, composed of LiFePO<inf>4</inf>, amorphous carbon and graphene layers, are then produced after rapid high temperature carbon treatment. Interface tunnel effect, produced by the intimate contact of LiFePO<inf>4</inf> particles with amorphous carbon and graphene layers, greatly improves the properties of the composites. Electrochemical tests indicate that the optimal amount of GO addition is 1 wt.% in terms of achieving a high electrochemical performance of the C-LiFePO<inf>4</inf>/G composites. Discharge capacity of the C-LiFePO<inf>4</inf>/G composites is 160.0 mAh g-1 at 0.2 C. When the current rate is further increased to 60 C, the discharge capacity of C-LiFePO<inf>4</inf>/G can reach 68 mAh g-1. At a high current rate of 20 C, the capacity attenuation rate of the C-LiFePO<inf>4</inf>/G electrode is only 9.6% after 200 cycles, showing excellent high-rate discharge capability and cycle performance. This is achieved under a facile synthesis condition of a simple procedure, low temperature, and normal pressure.
Journal of Power Sources295, 21429 (1 November 2015): 131–138.