Hackaday

Researchers have demonstrated a new supercapacitor design using lignin-derived porous carbon electrodes and a fluorinated diluent electrolyte (LiBF4 in sulfolane with TTE). The design achieves a 4 V operating voltage (vs. the typical 2.7 V), an energy density of 77 Wh/kg, significantly reduced self-discharge rates, and 90% capacity retention after 10,000 cycles — all improvements over conventional supercapacitors. While still at the lab prototype stage, the results suggest a promising path toward more practical energy storage devices.

Low Self-Discharge, High-Voltage Supercapacitors Using Porous Carbon