Hybrid and electric vehicles have already proven to be a global success; however the economical benefits and environmental gains of conventional hybrid vehicles have always been limited by the restrictions on battery-only driving distances. The use of lithium-ion batteries within Plug-In Hybrids (PHEVs) however could change all of this. More efficient and capable of producing up to 3 times the energy of a NiMh battery, lithium-ion technology is set to revolutionisethe hybrid vehicle market.
Whereas the battery pack in a conventional hybrid is charged exclusively from the on-board internal combustion engine and regenerative braking, a plug-in hybrid can be plugged into the mains and charged to give extended travel time running on battery power alone. PHEV’s are able to give drivers the best of both worlds, providing the performance and journey distance of conventional hybrid cards, whilst offering the substantial fuel economy, emission reduction, and petroleum displacement benefits of pure battery electric vehicles. With today’s ever increasing oil prices, electric and hybrid vehicles have never been so relevant, and with performance figures of over 100mpg it’s easy to see why PHEV’s are being hailed as the future of the auto industry.
Lithium-Ion Technology
Previous hybrid vehicles used nickel metal hydride (NiMH) batteries, which can be engineered for relatively short battery-only driving distances. The larger energy storage and electrical power capacity that lithium-ion battery technology provides however, means that next generation plug-in hybrids will be capable of travelling much further using battery power alone. PHEV designs currently beingtrialledboast top speeds of 62mph in EV mode and an electric-only range of 12.5 miles, a significant improvement on the previous 2 mile range of conventional hybrids.
The environmental gains and economical benefits of PHEV’s are significant, the increased power, endurance and acceleration in EV mode means that during town driving the vehicle is able to perform using battery only power, leaving the combustion
engine to kick in for higher speed driving or when battery power runs out. When the battery power does run down, PHEV’s operate like conventional hybrids and use the engine power and regenerative braking to charge the battery and drive the vehicle, eliminating the practicality issues with pure electric vehicles and their restricted travel distances.
The Future of Hybrid Vehicles
This extended battery-only power means reduced fuel consumption and lower emissions, especially when powered using electricity from renewable energy sources. Offering the best compromise between efficiency and usability, PHEV’s are predicted to be popular with consumers looking for increased economical benefits and environmental gains while retaining the function and performance of a conventional hybrid. Toyota are alreadytriallinga new plug-in hybrid version of their popular Prius, and with other manufacturers following closely in their lead and indicating the release of PHEV vehicles in the next 2 years, plug-in hybrids could soon be commonplace on our roads.
