Journal of Power Sources, Vol.195, No.18, 6031-6036, 2010
Si-graphite composites as anode materials for lithium secondary batteries
Two types of Si-graphite (Si-C) composites are synthesized and evaluated for anode materials of lithium secondary batteries. The mechano-chemical milling and the rotational impact blending methods are applied to synthesize two types of Si-C composites. Graphite powders having Si on the surface (type A) is synthesized by mechano-chemical milling using the pitch as a binder. Si embedded inside the graphite particle (type B) is synthesized by rotational impact blending. The loading level of Si is about 20 wt% for both type Si-C composites. The location of Si is verified by observing cross sectional images of particle and conducting EDS mapping. The initial discharge capacity of type B has larger value than that of type A, while the type A shows better cycle performance than type B. The efficiency of first cycle is about 87% for both types A and B. (C) 2010 Elsevier B.V. All rights reserved.
Keywords:Lithium secondary battery;Anode materials;Silicon;Silicon-graphite composites;High capacity