Closing the electric power gap

Battery and hybrid-powered vehicles are making inroads into the markets faster than many predicted, with General Motors being one of the first off the start line following the launch of its Chevrolet Volt.

“Skeptics have suggested it would probably be many years before lithium-ion batteries with significantly lower cost and higher capability are available, potentially limiting sales of electric vehicles for the foreseeable future,” said Jon Lauckner, president of GM Ventures. He was commenting on the announcement that General Motors Ventures was investing US$7-million in Newark, Calif.-based Envia Systems to provide GM’s battery engineering team with access to advanced lithium-ion cathode technology that delivers higher cell energy density and lower cost. “In fact, our announcement today demonstrates that major improvements are already on the horizon,” said Lauckner. Other investors in Envia are Asahi Kasei and Asahi Glass, Bay Partners, Redpoint and Panagea Ventures. In a separate agreement, GM secured the right to use Envia’s advanced cathode material for future GM electrically driven vehicles.  

“With our high-capacity manganese rich cathode material, Envia is addressing two key issues in the next-generation battery cells – higher capability and lower cost,” said Atul Kapadia, founding investor, chairman and CEO of Envia Systems. 

“Our test results on small-format cells show that Envia’s high-capacity composite cathode material can increase the energy density of lithium-ion cells by up to one-third, at an equivalent level of reliability, safety and durability,” said Micky Bly, GM executive director for Electrical and Battery Systems. “We estimate this improvement in cell energy density and less expensive material will drive a substantial reduction in cell cost, leading to lower cost battery packs like the one in the Chevy Volt,” he said.

Looking at the end of the life-cycle, General Motors has also announced that it will work with the ABB Group to develop pilot projects for re-using the batteries from the Chevrolet Volt electric vehicle. The two companies are collaborating to determine how the Volt’s 16-kWh lithium-ion batteries can be used to provide stationary electric grid storage systems once the batteries have fulfilled their usefulness in customers’ vehicles. “The Volt’s battery will have significant capacity to store electrical energy, even after its automotive life,” said Bly. “That’s why we’re joining forces with ABB to find ways to enable the Volt batteries to provide environmental benefits that stretch far beyond the highway.” The Volt battery has an eight year warranty covering all 161 battery components, 95% of which are designed and engineered by GM.

Automotive Industries (AI) asked Bly whether the company was prepared for the reception that the motoring public has given the Volt.

Bly: We’re gratified to see the great public reaction to the Volt. We’re still in the initial launch phase of the vehicle but our customers who have taken delivery of their Volt are telling us the Volt has surpassed their expectations. The entire Volt engineering team continues to work hard to make sure we’re delivering the best vehicle with the highest quality to our customers every day.

AI: Is the Volt just another model in the GM garage, or does it signify something bigger within the company in terms of your future direction?

Bly: I can tell you that the entire GM team is working hard to develop new opportunities to expand the reach of the Volt’s innovative propulsion technology. But we’re looking beyond the Volt to other electrification technologies that can help customers save money by reducing fuel consumption. We recently introduced our eAssist “light electrification” technology that will debut on the 2012 Buick LaCrosse and Buick Regal later this year—this technology uses electrification to provide start-stop functionality and electric boost capability to provide customers with world-class fuel economy of up to 37 MPG highway. We’ve also announced our commitment to studying full battery electric vehicles by launching demonstration fleets in Korea, Germany and China. GM is committed to electrification in a big way and we’re going to lead in this technology going forward.

AI: What is expected of the supply chain to support this?

Bly: There’s no doubt our supply chain has had to diversify, just like us. The technologies we’re looking at require some ‘out of the box’ thinking and I am happy to say our suppliers have been strong partners along the way. We expect that we’ll continue to forge strong bonds with our suppliers to make sure we’re getting the best technologies at reasonable costs that allow us to continue to design, build and sell the best vehicles in the world.

AI: Hybrid and electric vehicles have opened the door to a number of suppliers which traditionally have not been part of the motor industry. What challenges has this created, and how have you solved them?

Bly: It’s an interesting question. When we began the process of developing the Volt’s battery system it required us to look way beyond our traditional supply base. We held a competition of sorts to determine who had the best technology. We settled on LG Chem and I’ll tell you that going into this we had no idea how we were going to produce a cell that would meet the traditional automotive quality standards. Thanks to the hard work of the LG Chem and GM engineering teams we were able to develop the technology and it has exceeded all of our internal targets for quality and durability. That’s probably the biggest challenge we faced and overcame during the development of the Volt.

AI: Do you see more non-traditional suppliers entering the motor industry?

Bly: I do. Our partnership with start-up companies is a clear sign of how were looking outside of our traditional supply base to find ways to accelerate our technology deployment. We’re being aggressive in looking for new ways to adopt cutting edge technologies at reduced costs that will make our vehicles the best in the world.
AI: What will the major growth and demand areas within your sphere of business be?

Bly: For my team, we’re focused on expanding the deployment of electrification technologies. We expect to see major growth in the adoption of all forms of electrification going forward, from start-stop systems to hydrogen fuel cell vehicles.

eAssist – how it works

GM’s eAssist system uses power stored in the battery to provide electrical boost in various driving scenarios, optimizing engine and transmission operation, according to the company. 

“The battery system is designed to provide power assistance to the internal combustion engine, rather than store energy for all-electric propulsion,” says Steve Poulos, global chief engineer of the eAssist system. “It’s really an extension of the conventional internal combustion engine, not a replacement for it.”

The eAssist system’s 115V air-cooled lithium-ion battery supports a 2.4L Ecotec four-cylinder engine with approximately 11 kW (15 hp) of electric power assist during heavy acceleration and 15 kW of regenerative braking power. While in fuel shut-off mode, the induction motor-generator unit continues spinning along with the engine to provide immediate and smooth take-off power when the driver presses on the accelerator. 

Then, as the vehicle comes to a stop, the induction motor-generator unit spins the engine, bringing it to a smooth stop – properly positioned for a smooth restart. An auxiliary, electric-driven transmission oil pump keeps the transmission primed and the fluid flowing when the engine shuts down at a stop. 

The eAssist power pack consists of a lithium-ion battery pack, an integrated power inverter and 12V power supply. It is located in a compartment between the rear seat and trunk; and weighs about  65 pounds (29 kg). Trunk space is slightly reduced when compared with 2011 models with the four-cylinder/six-speed powertrain, but still offers 11.1 cubic feet (314 liters) of storage. An  electric fan cools the power pack, drawing air from a vent located in the package tray, behind the rear seat.

An electric induction motor-generator is mounted to the engine in place of the alternator to provide both motor assist and electric-generating functions through a unique engine belt-drive system. The induction motor-generator is a high-performance, compact induction motor that is liquid-cooled for increased performance and efficiency.

Power is transferred to the wheels through a “next-generation” six-speed automatic powertrain.