Development of ultra-battery for hybrid-electric vehicle applications

Transport is one of the largest sources of human-induced greenhouse gas emissions and fossil-fuels consumption. This has lead to a growing demand for hybrid-electric vehicles (HEVs) to reduce air pollution and consumption of fossil fuels. CSIRO Energy Technology has developed the ultra-battery, a new technology that will reduce the cost and boost the performance of batteries in HEVs. The ultra-battery is a hybrid energy-storage device, which combines an asymmetric supercapacitor, and a lead-acid battery in one unit cell, taking the best from both technologies without the need for extra electronic controls. The capacitor will enhance the power and lifespan of the lead-acid battery as it acts as a buffer in discharging and charging. Consequently, this hybrid technology is able to provide and absorb charge rapidly during vehicle acceleration and braking. The ultra-battery has been subjected to a variety of tests. To date, results show that the discharge and charge power of the ultra-battery is similar to 50% higher and its cycle-life is at least three times longer than that of the conventional lead-acid counterpart. Furthermore, the ultra-battery is able to be produced as either flooded-electrolyte or valve-regulated designs in the existing lead-acid factory and also able to reconfigure for a variety of applications, such as conventional automobile, power tool, forklift, high-power uninterruptible power supply and remote-area power supply. The prototype ultra-batteries have been constructed and are under laboratory evaluation and field trial. The success of the ultra-battery will obviously make HEVs more affordable and widespread. This, in turn, will reduce greenhouse gas emissions in the urban environment and the consumption of limited supplies of fossil fuels. (c) 2006 Elsevier B.V. All rights reserved.