Article ID | Journal | Published Year | Pages | File Type |
---|---|---|---|---|
10567380 | Journal of Power Sources | 2005 | 7 Pages |
Abstract
Anodes derived from oxides of tin have, of late, been of considerable interest because, in principle, they can store over twice as much lithium as graphite. A nanometric matrix of Li2O generated in situ by the electrochemical reduction of SnO2 can provide a facile environment for the reversible alloying of lithium with tin to a maximum stoichiometry of Li4.4Sn. However, the generation of the matrix leads to a high first-cycle irreversible capacity. With a view to increasing the reversible capacity as well as to reduce the irreversible capacity and capacity fade upon cycling, tin-tin oxide mixtures were investigated. SnO2, synthesized by a chemical precipitation method, was mixed with tin powder at two compositions, viz., 1:2 and 2:1, ball-milled and subjected to cycling studies. A mixture of composition Sn:SnO2 = 1:2 exhibited a specific capacity of 549 mAh gâ1 (13% higher than that for SnO2) with an irreversible capacity, which was 7% lower than that for SnO2 and a capacity fade of 1.4 mAh gâ1 cycleâ1. Electrodes with this composition also exhibited a coulombic efficiency of 99% in the 40 cycles. It appears that a matrix in which tin can be distributed without aggregation is essential for realizing tin oxide anodes with high cyclability.
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Physical Sciences and Engineering
Chemistry
Electrochemistry
Authors
A. Sivashanmugam, T. Prem Kumar, N.G. Renganathan, S. Gopukumar, M. Wohlfahrt-Mehrens, J. Garche,