Nanodispersed iron, tin and antimony in vapour grown carbon fibres for lithium batteries:: an EPR and electrochemical study

The use of iron-, tin- and antimony-containing carbon fibres as potential candidates for the negatives electrode of advanced lithium-ion batteries is described. Two different types of fibres are used: non-graphitic and partially graphitized carbon. EPR results show that both carbon and dispersed iron participate in redox processes during the electrochemical reaction with Li. Lithium test cells evidence higher capacities for partially graphitized fibres. The addition of dispersed tin or antimony is used to improve the capacity of the non-graphitic fibres by formation of lithium-tin and lithium-antimony compounds. Reversible capacity values close to 300 mA h g(-1) are achieved in both partially graphitized and composite electrodes containing Li-alloying elements. The use of nanodispersed transition metals, i.e. iron, in a carbon matrix is proposed here as an alternative to carbon composites containing Li-alloying elements. (C) 2004 Elsevier Ltd. All rights reserved.