Electrochemical analysis graphite/electrolyte interface in lithium-ion batteries: p-Toluenesulfonyl isocyanate as electrolyte additive

Lithium plating and dendrite formation can occur on the graphite surface at high current densities. What is more, graphite generates a 10% volume change during cycling, resulting in a solid electrolyte interface (SEI) crack and further electrolyte decomposition. Here, p-Toluenesulfonyl isocyanate (PTSI) as an electrolyte additive is evaluated to overcome the above problem of Li/graphite cells. The results show that the cycling capacity of Li/graphite cell with 0.5 wt% PTSI is effectively enhanced at high current densities. Remarkably, we find that a stable SEI film derived from PTSI is generated on the graphite surface. The SEI film can obviously inhibit the reductive decomposition of electrolyte, electrode erosion and LiF formation upon cycling. This additive will provide new avenues for the rational engineering of advanced Li-ion batteries.