Application of a Ti-Ni alloy as a current collector of positive electrode for lithium/sulfur batteries

摘要

A 49.8 at.%Ti-50.2 at.%Ni shape memory alloy was applied to a current collector of positive electrode for lithium/sulfur (Li/S) battery. Flexible austenitic phase having pseudoelasticity dominated in the Ti-Ni current collector at room temperature. In the discharge curve, two plateau regions due to the lithium polysulfide (Li_2S_n) and the lithium sulfide (Li_2S) were obviously observed. The initial discharge capacity was 1068 mAh/g for Li/S cell with the Al current collector, and that of the cell with the Ti-Ni current collector reached 1140 mAh/g. A little bit of declined cycle performance was associated with decreased sulfur utilization owing to a reaction with dissolved Ti and Ni elements. Compared with the Al current collector used commercially, the Ti-Ni alloy with pseudoelasticity was more suitable to apply for the current collector of Li/S battery.