General Motors Chairman Rick Wagoner announced at the Geneva Motor Show today that GM will introduce into production a second-generation version of the GM Hybrid System equipped with a lithium-ion battery system from Hitachi Vehicle Energy Ltd (HVE), a subsidiary of Tokyo-based Hitachi Ltd.
The Li-ion pack will help make the next-generation GM Hybrid System—the mild hybrid belt-alternator-starter system applied in the Saturn Vue; Saturn Aura; Chevrolet Malibu; and Buick LaCrosse Eco-Hybrid in China (earlier post)—nearly three times more powerful than the system it replaces. Overall fuel economy improvements for cars and trucks using the system are expected to be up to 20%, depending on engine and vehicle application.
By building on this system, Wagoner said, GM will be able to make the GM Hybrid System more cost-effective and expand its application in GM’s global vehicle portfolio.
In order to have a real impact in reducing oil consumption, oil imports, and CO2 emissions, advanced technologies must be affordable enough to drive high-volume applications. We plan to roll out this next-generation hybrid technology globally, across our brands and regions, starting in 2010 in North America, and we expect that volumes will eventually exceed 100,000 units annually.—Rick Wagoner
The next-generation GM Hybrid System will complement GM’s Two-Mode Hybrid system as part of the company’s advanced powertrain portfolio. The Two-Mode Hybrid system debuted in 2007 in the Chevrolet Tahoe and GMC Yukon, and will be offered this year in the Cadillac Escalade full-size SUV and the Chevrolet Silverado and GMC Sierra full-size pickups. The first front-wheel-drive application of the Two-Mode Hybrid system will debut in the 2009 Saturn Vue Green Line.
The increased power from the lithium-ion battery will allow the next-generation GM Hybrid System to be used in a wide range of global powertrains, including naturally aspirated engines, new high-efficiency turbocharged engines, bio-fuel engines and diesels.
This technology is showcased in the Saab 9-X BioPower Hybrid concept car, which made its debuted at the Geneva Motor Show. The Saab concept is capable of 117 g CO2/km, or projected fuel consumption of 4.9 l/100 km (48 mpg) when running on gasoline over the combined cycle. (Earlier post.)
Features supported by the next-generation GM Hybrid System include:
Turning the engine off at idle;
Offering brief electric-only propulsion;
Using a more powerful electric motor to enhance engine efficiency;
Extending fuel cutoff during deceleration;
Extending regenerative braking to recapture more energy;
Performing intelligent hybrid battery charging
For additional energy savings, an advanced six-speed automatic transmission also may be used, depending on the vehicle application.
The current GM Hybrid System was introduced in 2006 on the Saturn Vue Green Line SUV. By the end of 2008, GM will offer eight hybrid models in North America and nine worldwide. GM will introduce 16 new hybrid vehicles over the next four years.
Hitachi Vehicle Energy Ltd. Hitachi Vehicle Energy Ltd. was formed in 2004 as a joint venture between Hitachi, Shin-Kobe Electric Machinery Co. Ltd. and Hitachi Maxwell Ltd. to develop, manufacture and market rechargeable lithium-ion batteries for hybrid electric vehicles and other applications.
In January, the partners injected ¥6 billion (US$58 million) to the JV company to strengthen its production and development capabilities. Following the capital increase, capital ratios of Hitachi, Shin-Kobe Electric Machinery and Hitachi Maxell will be 64.9%, 25.1% and 10.0%, respectively.
HVE is working with a layered nickel manganese cobalt oxide (NMC) cathode material and a graphite anode.
Hitachi expects the global market for HEVs to continue expanding from the 410,000 unit level recorded in 2006 to 1.5 million units in 2010. Against this backdrop, Hitachi estimates that demand for HEV lithium-ion batteries will overtake that for the current mainstream nickel metal hydride batteries in 2015.
Hitachi Chemical Co. is expanding its output capacity for graphite materials used in lithium-ion battery anodes by 20%. (Earlier post.)
Hitachi also produces power electronics and motors for application in hybrid and electric vehicles. The company already provides the motor in the first generation GM Hybrid System: a 4kW (mechanical) machine with 5kW generating power, delivering some 60 Nm of motoring torque.
Juichi Arai, et. al., High-power and High-energy Lithium Secondary Batteries for Electric Vehicles. Hitachi Review, Volume 53 Number 4 November 2004
Juichi Arai, et. al. Development of a high power lithium secondary battery for hybrid electric vehicles. Journal of Power Sources Volume 146, Issues 1-2, 26 August 2005, Pages 788-792