Sn/Al2O3/C/CNT composite prepared by wet milling as anode material for lithium-ion cells

Sn/Al2O3/C/CNT (SAC/CNT) composite was synthesized by a simple wet milling route. The physico-chemical, structural and morphological properties of the material were studied. The electrochemical performance of the composite as an anode material in Li-ion cells was evaluated by Cyclic Voltammetry (CV), charge-discharge cycling and electrochemical impedance measurements. The SAC/CNT material delivered an initial specific capacity of 835 mAh g−1 with the coulombic efficiency of ∼77% along with good charge-discharge cycle performance retaining ∼88% of the initial capacity after 35 cycles. A comparison of the results with those for Sn/C (SC) and Sn/Al2O3/C (SAC) showed that the SAC/CNT composite exhibited better overall performance compared to the other two materials. The enhanced performance of SAC/CNT is attributed to the combined effect of the buffer action provided by Al2O3 accommodating volume changes of the electrode during cycling and the reduced charge transfer resistance of the electrode resulting from the inclusion of conductive CNTs.