On the Influence of Ball Milling Time on the Structure and Electrochemical Performance of (Sn<inf>71</inf>Co<inf>29</inf>)<inf>50</inf>C<inf>50</inf> wt% Anodes for Li-Ion Battery Applications

Ball milled SnCoC composites are an attractive commercial anode material to conventional graphite due to their higher specific capacity and low temperature performance. The effect of ball milling time on the structure and electrochemical properties of the (Sn71Co29)50C50 wt% composite anodes are studied to understand the reasons for the non-realization of the theoretical capacity. Structural analysis reveals the damage of graphite structure with increasing ball milling time from 10 h to 60 h. The cyclic voltammetry and differential capacity measurements indicate the decreasing contribution to capacity from graphite and increasing contribution from Sn with increase in the milling time. The charge-discharge cycling of the anodes at different C rates indicates that though the specific capacity does not improve with longer milling time, the rate capability improves significantly. The damage in the graphite structure during high energy ball milling is found to reduce the capacity of the SnCoC anodes. Based on the investigations, it can be concluded that 10 h of milling time is optimum to realize high specific capacity, whereas longer durations of milling are desirable for high rate discharge characteristics.