One of the most common questions asked of electric-vehicle manufacturers is what happens to battery packs at the end of their use cycle in a vehicle. The image of a battery leaking chemicals into a landfill is unsettling to many prospective buyers. But some automakers are considering how to repurpose the packs to harness whatever utility may remain in their cells.
General Motors and Nissan estimate that after 10 years, batteries in the Chevrolet Volt and Nissan Leaf will have 70 percent of their life remaining. And as the automakers explore recycling options, they’re looking into new opportunities for those still-useful batteries as backup electric power for utilities and homes. According to G.M., a power unit incorporating 33 Volt packs could store enough energy to supply 50 homes — during a blackout, for example — for four hours.
G.M. is working with ABB Group, which specializes in power and automation technologies, on battery reuse. On Tuesday, at an ABB research lab in North Carolina, the two companies demonstrated an early-stage storage system using an ABB electric inverter and Volt battery pack. Their plan is to build a prototype that will demonstrate the viability of grouped E.V. batteries storing and feeding power back to the grid, including renewable energy from wind or solar installations.
“Our target has always been a field demonstration with a used battery and appropriate electronics to support the electric grid,” said Sandeep Bala, an ABB research engineer, during a teleconference Wednesday.
“The Volt customer is very focused on the whole life cycle of the battery and, because the cells were designed to be very robust, there’s still very significant battery life after 10 years in the car, added Pablo Valencia, G.M.’s senior manager for battery life management, during the teleconference. “Working with ABB, we want to provide leadership in secondary use,” he said.
Mr. Valencia said that the predictability of used E.V. packs “is actually higher than with brand-new batteries. They become more stable over time.”
Nissan’s exploratory program also includes reuse and recycling options. Ken Srebnik, senior manager of corporate planning, said in a telephone interview that Nissan had been working with Sumitomo Corporation since 2009 on Leaf battery-based energy storage devices. In household applications, the storage could back up a residential photovoltaic system, he said. A somewhat larger system has applications for community energy storage, providing extra power for several homes connected to a single transformer.
Additionally, Nissan is working with Toxco, a battery recycler, on the eventual dismantling and material reuse of Leaf packs in North America.
Other automakers are taking similar steps, including Tesla Motors, which has recycling partnerships in North America and Europe. The closed-loop recycling process used by its European partner, Umicore, is “able to recycle our batteries into completely reusable materials and substantially reduce the carbon footprint of manufacturing lithium-ion batteries,” Tesla said in a news release.
Roger Ormisher, a spokesman for Fisker Automotive, said in an e-mail that “battery reuse and recycling is on our agenda, but we don’t have specific plans in place yet.”
The New York Times