High Energy, High Power Supercapacitor-Battery Hybrid Energy Storage System

This proposal presents a Phase I SBIR project to develop high-energy, high-power supercapacitor-battery hybrid energy storage systems. Batteries are widely used, but have limited power capability and cycle life. Supercapacitors, also called ultracapacitors or double-layer capacitors, are rechargeable electrical energy storage devices Supercapacitors offer higher power, and greater cyclability than batteries. However, their lower energy density limits operation time of electrical equipment running on supercapacitors alone. Neither battery nor supercapacitor technology alone offers both high power and high energy. Therefore, a hybrid (battery–supercapacitor) system is needed for an optimum combination of power and energy density. Although the supercapacitor is mainly a high-power device in a hybrid configuration, the supercapacitor’s energy density is important. Increased energy density allows high power output for longer times. Conventional activated carbon for supercapacitors has limited pore size control, limiting device energy density. This project will develop supercapacitor-battery hybrids utilizing supercapacitors incorporating nanoporous carbide-derived carbon electrodes providing higher volumetric and gravimetric capacitance than existing materials. The manufacturing process explored in this SBIR relies on synthesis of nanoporous carbon with controlled pore size, leading to hybrid power storage devices with energy density (> 500 Wh/L) and supplying power > 500 kW for at least 5 minutes.