Working with car companies, battery developers and policy makers, University of Michigan researchers have developed a framework to help stakeholders navigate toward a future with better, more affordable and more sustainable electric vehicles.
“I think of it as a break-out story. How do we break out of this complex puzzle where we’re trying to benefit the environment, to help the industry compete and to be cost-effective for consumers?” said Greg Keoleian, a professor at the U-M School for Environment and Sustainability, or SEAS. Keoleian, who is also the co-director of the U-M Center for Sustainable Systems, or CSS, is the senior author of a new study published in the Journal of Energy Storage detailing the framework.
“You have all of these interested parties that can have different goals and objectives, so how do you align those?” Keoleian said. “Our framework helps stakeholders consider a holistic set of factors to achieve better outcomes for batteries and electric vehicles.”
With input from experts in academia, industry and government, Keoleian and colleagues assessed economic, environmental and social trade-offs and outlooks from the perspective of stakeholders across the entire battery life cycle. This enabled the team to create a framework that stakeholders—from battery and vehicle manufacturers, to drivers, to battery recyclers—can use to better understand, anticipate and prepare for trade-offs and consequences as they make decisions and set priorities.
The assessments also underscored the various challenges facing EVs from various perspectives. That includes an oil industry with federal support and a vested interest in internal combustion engine vehicles that also have more mature cradle-to-grave infrastructure, Keoleian said. But he is still optimistic the framework can help accelerate EV transition.
“There are multiple problems that need to be addressed in this journey, but ultimately these vehicles outperform internal combustion engine vehicles,” Keoleian said. “They are quieter. They don’t have tailpipe pollution and they’re better for the environment. You get better acceleration, you have less maintenance costs, lower operating costs and the lowest total cost of ownership. We know that they are the future.”
Trade-offs and chemistry case studies
Looking at the different battery chemistries that are being used and developed for EVs helps provide concrete examples of the types of trade-offs highlighted by the framework. In China, where more than 60% of new car sales are electric, EV manufacturers have come to rely on a battery chemistry using lithium iron phosphate, abbreviated LFP. Compared with another popular battery chemistry known as NMC for its nickel, manganese and cobalt components, LFP batteries are less expensive.
“EV adoption is really influenced by cost and the battery is about 30% of the cost of an electric vehicle,” Keoleian said. “LFP is less costly because of the chemistry—it doesn’t have the cobalt and the nickel.”
But LFPs require more battery mass to achieve the same level of charge storage as NMCs. That translates to less range for an LFP vehicle. And because cobalt and nickel are valuable, there’s more incentive to recycle these batteries, which would let battery makers create them more sustainably, by mining less new materials for each new battery.
American automakers, including Ford and General Motors, are also developing what are called LMR batteries, or lithium manganese-rich batteries, that have potential to marry the low cost of LFPs with the longer range of NMCs. Their durability, however, is a work in progress.
“There are a lot of different trade-offs and this framework helps elucidate what they are from different stakeholder perspectives,” Keoleian said. “If you have blinders on, you can think you’re really improving sustainability and performance, but you may actually be causing problems somewhere upstream or downstream.”