Lithium intercalation and deintercalation reactions in synthetic graphite containing a high dispersion of SnO

SnO-graphite composites containing up to 30 wt % of SnO were prepared by sl ow hydrolysis of SnCl2 in the presence of graphite powders. Best applicatio n performance was delivered by a composite containing 13.6 wt % of SnO, of which the specific capacity is 450 mAh/g at the C/6 rate and decreases by 1 2% after 30 cycles. This is a substantial improvement over unsupported SnO which, despite a larger initial capacity (870 mAh/g theoretical), would los e 52% of the capacity in the same number of cycles. In our opinion, the duc tility and conductivity of the graphite matrix, a high dispersion of the Sn O phase, and the presence of Li2O barrier layers formed in the first electr ochemical decomposition reaction of SnO, work in unison to stabilize Sn mic roparticles against agglomeration, the established cause of application pro blems in tin composite oxide based anode materials. (C) 2000 The Electroche mical Society. S1099-0062(99)12-055-8. All rights reserved.