Preparation And Investigation Of Carbon-based And Tin-based Anode Materials For Li-ion Batteries

Lithium-ion batteries with superior energy density have attracted considerable attention due to their successful applications in portable electronic devices such as cell phones, digital cameras, laptops, and potential applications in hybrid electric vehicles. Today, graphite is the most commonly used anode material. However, the theoretical capacity of graphite (372 mA h/g) is not high enough to meet the demands for batteries. Increasing efforts have been diverted to the exploration of new anode materials. In our experiment, the biomass resources have been used as the raw materials to produce porous carbons through simple carbonization and activation. The obtained porous carbons can be used as the matreials in electrode fabrication, catalysis and gas storage. In addition, SnO₂ core-shell nanostructures have been prepared by a simple template-assisted hydrothermal method and applied lithium battery anode materials.Microporous carbons with a high surface area have been prepared from cornstalks via simple carbonization and activation. The pore size of the microporous carbons remains in the range of 1-2 nm, whereas the BET surface area depending on the concentration of the activation agent (KOH). Our results show that the microporous carbon is able to adsorb considerable amounts of H₂, CO₂ and CH₄.Porous carbon materials with a high surface area and a hierarchical porous network have been prepared from rice straws. Our results show that the macroporous channels derived from the raw rice straws and micropores generated during the carbonization and activation processes provide the pathways for easy accessibility of electrolyte and fast transportation of lithium ions and electrons. The porous carbon materials give a particularly large reversible capacity at high charge/discharge rates.A series of porous carbons have been derived from cornstalks, rice straws, pine needles and pinecone hulls. Our results show that the biomass texture and the activation manner determine the surface areas of the porous carbons. High surface area porous carbons can be obtained from the biomass materials with a loose texture whereas the porous carbon derived from a raw material with a compact texture has a much smaller surface area. The amount of activation agent, the activation temperature and the activation time also affect the surface area of the porous carbons to a considerable extent. We investigate the properties of porous carbon derived from pine needle used as the anode materials of lithium-ion battery. In addition, the obtained porous carbons can be used as catalyst supports in cinanamaldehyde hydrogenation, the cycling performances of the high-surface-area carbon materials being distinctly superior to that of the commercial activated carbon.SnO₂ core-shell nanostructures have been prepared by a simple template-assisted hydrothermal method. Our SnO₂ nanostructures give a particularly large reversible capacity and cycled well as anode materials for lithium ion batteries. The texture obviously affect the electrochemical performance of SnO₂ nanostructures.