Study of the cycling performance of finely dispersed lithium alloy composite electrodes under high Li-utilization

The cycling behavior of lithium alloy composite electrodes in liquid electrolyte composed of 1 M LiClO4/EC+DEC (1:1) was examined. The lithium alloys were formed by electrochemical insertion of lithium into metallic host matrices (Al, Sn and SnSbx powders). With a wide potential cut-off between 0.1 and 1.2 V vs. Li/Li+, the capacity retention (ca. 550 mA h/g) of Sn-based electrodes during cycling can be remarkably improved by decreasing the particle size of the host materials to near nano-scale. Moreover, the cycle life performance and coulombic efficiency are also dependent on polymer binder and conducting additive as the other components of the electrodes. Under a similar condition, it was found that an ultra-fine Al powder was not fit for host material due to a strong passivation of the electrode after Li-insertion.