Low-Cost, Environmentally Benign, High Specific Power Manganese Dioxide-Carbon Pseudocapacitors for Hybrid Vehicles

76215-Both current and next generation hybrid electric vehicles (HEVs) require improved low-cost energy storage devices that both receive and deliver high peak power pulses. This project will develop a unique low-cost pseudo ultracapacitor, suitable for handling the peak power storage/delivery needs of hybrid electric vehicles. The device will combine a new high performance, inexpensive, nonpolarizable, Faradaic-manganese dioxide electrode with a well developed carbon-based capacitive electrode using an alkaline electrolyte. Phase I will develop processing conditions necessary to produce the high conductivity Faradaic electrode, suitable for HEV peak power pulses, from an inexpensive electrodeposited manganese dioxide. In particular, samples of high performance MnO2 electrodes will be fabricated and tested to demonstrate that they can achieve the required HEV performance parameters of high specific power (greater than 1.5 kW/kg), good specific energy (greater than 5 Wh/kg), and excellent cycle life (greater than 300,000 charge/discharge cycles at 1 Wh/kg). A manufacturing cost analysis will be conducted to demonstrate that the low cost goals are achievable. Commercial Applications and Other Benefits as described by the awardee: The ultracapacitor should replace expensive, expendable batteries as the principal energy storage/delivery device for the high peak power pulses associated with regenerative braking and acceleration in HEV acceleration. This would allow HEVs to economically compete with their internal combustion engine counterparts. In turn, the large-scale replacement of internal-combustion-powered vehicles with HEVs would reduce exhaust emissions and gasoline consumption, with a consequent reduced dependence on oil imports.