The Combination Of Graphene And Metal Oxide Anode Material

Compared with the conventional secondary batteries such as lead acid, nickel, chromium, nickel metal hydride batteries, lithium ion battery has many advantages. In lithium ion batteries, the most decisive is the performance of the cathode and anode materials. Compared with the cathode material, anode material has bigger effect on the battery capacity, and the commercial anode materials are mainly carbon materials. But in the charge and discharge process the formation of SEI film makes the lithium ion with larger irreversible loss, influence the capacity of the battery, there’s an urgent need to find new and highly efficient lithium ion battery anode materials.Metal oxide anode materials generally has high theoretical specific capacity, titanium dioxide as a kind of important inorganic semiconductor materials, compared with the conventional graphite anode, has high voltage work platform, good cycling performance and high theoretical specific capacity. Fe2O3 and SnO2 with the advantage of low cost, environmentally friendly, high tap density, high voltage platform and excellent theoretical specific capacity (approximately 1007 mAh/g), has been widely researched. But the large volume change during the charge and discharge process and low electronic and ionic conductivity are big problems, in order to solve these problems, compound the metal oxides with graphene, which has excellent conductive performance, large specific surface area.1, Graphene has been synthesized with the improved synthesis method of Hummers, the morphology of the material has been characterized and the results showed that the layered oxidation graphene has large specific surface area.2, TiO2/rGO composites were synthesized without any additive and templates, the morphology and the electrochemical performance of the materials have been characterized and the results showed that the composite materials have better chemical performance compared with the bare TiO2, and the composite with 5% GO has the best performance. At the current density of 0.1C(C=150 mA/g), after 50 cycles, the specific capacity of the composites remained at 186.7mAh/g, about 55% of the capacity is maintained.3, Fe2O3/SnO2/rGO composites have been synthesized by the hydrothermal method, the morphology and the electrochemical performance of the materials have been characterized and the results showed that the composite materials have better chemical performance compared with the Fe2O3/SnO2. At the current density of 0.1C(C=400 mA/g), after 50 cycles, the specific capacity of the composites remained at 303mAh/g, about 23% of the capacity is maintained.