Researchers at the Japan Advanced Institute of Science and Technology (JAIST) have developed a chemical additive called pentafluorophenyl thiophen imine (FPTI) for graphite anodes in lithium-ion batteries. This substance facilitates the formation of a protective film on the anode surface during initial charging cycles, which prevents rapid degradation of the battery cell.
The protective layer allows lithium ions to move between the electrolyte and the anode without triggering unwanted chemical reactions. By stabilizing this interface, the additive reduces the consumption of active lithium and prevents an increase in electrical resistance, which typically accelerates capacity loss in standard battery cells.
In laboratory experiments, cells with a 4 mg/ml concentration of FPTI retained 95.6% of their initial capacity after 1000 charge cycles. A lower concentration of 2 mg/ml resulted in 89.4% capacity retention. In contrast, a control sample without the additive retained only 62.7% of its capacity after the same number of cycles.
The study also noted improvements in energy density. Cells with 4 mg/ml of FPTI reached 233 Wh/kg, compared to the baseline of 130 Wh/kg. Researchers emphasized that the additive is most effective when applied during the graphite anode preparation stage, rather than being added directly to the electrolyte of assembled cells.
