Preparation and characterization of carbon cryogel (CC) and CC-SiO composite as anode material for lithium-ion battery

Carbon cryogel (CC) has been prepared through sol-gel polycondensation of resorcinol (R) with formaldehyde (F) followed by freeze-drying and carbonization in this work. The characteristics and lithium-ion insertion-extraction property have been investigated for the first time. Based on the results that CC has very excellent cycling stability but very limited lithium-ion charge-discharge capacity, SiO is employed to synthesize CC-SiO composite by high energy mechanical ball-milling to improve the applicability. The results showed that, CC-SiO is composed of active carbon, graphite, SiO and dispersed Si crystal, while CC is composed of active carbon and graphite. CC-SiO has smaller and much more uniform particles than CC. SiO can greatly improve discharge capacity of CC with an acceptable sacrifice of cycling stability, and the charge-discharge capacity of CC-SiO comes mainly from lithium insertion-extraction in Si-SiO in the sample. CC-SiO has excellent high-rate discharge ability and is promising anode material of lithium-ion battery for use of high power density purpose. (c) 2008 Elsevier Ltd. All rights reserved.