End of life options & impacts of EV batteries

10/28/2016

By: Shannon Walker

As worldwide electric vehicle (EV) sales are expected to grow exponentially over the next decade, an important question is raised: What will be done with used EV batteries? Once the vehicle’s battery packs have reached the end of their life, their disposal raises general space and transportation challenges, as well as concerns about their environmental and human health impacts.

These concerns may be somewhat exaggerated in the minds of general consumers. “Battery waste” sounds terrifying — rightly so, as traditional lead-acid batteries are highly toxic and unsafe for landfills. But lithium-ion batteries (Li-ION), which are used in the majority of EVs, are actually not considered toxic, and can be disposed of in a landfills.

This is a bit deceiving as lithium is still a highly reactive element. Rarely these battery packs have burst into flames upon failure. But overall the benefits of Li-ION technology outweigh the concerns, leading to their widespread adoption in EVs over other available battery technologies.
An arguably bigger problem for landfill disposal of EV batteries is actually space. With nearly 1 million lithium-ion batteries on the road today weighing over 600 lbs. each, and local landfills already nearing capacity, there simply isn’t enough room to “dispose” of all these batteries in this way.

But no EV battery should end up in a landfill,
from an environmental but also economic perspective.

Used EV batteries still hold major value,
even when they aren’t strong enough to power vehicles.

Over time EV batteries lose their ability to hold a charge, almost like a used sponge just can’t hold as much water. How long this actually takes depends on a variety of factors, but roughly an Li-ION EV battery might last 100,000 miles or 5 years of typical driving. At this point though, the battery can still hold ~80% of its charge, which lends these batteries to a variety of other uses.

Used EV batteries can be repurposed to store energy for homes, commercial buildings, and even electric utilities. As more electricity is produced from renewable sources including wind and solar, repurposed EV batteries become valuable assets in capturing and holding electricity at the time of production.

Several major utility companies are contracting with auto manufacturers to explore ways they can utilize repurposed EV batteries to deal with critical storage issues. Better energy storage can help utilities avoid the high cost of turning on “peaker plants”, power plants that are run occasionally only to meet peak electricity demand. Plus, the renewable energy stored in batteries is far better for the environment than energy produced by natural gas peaker plants.

Both GM and Nissan have also piloted projects to repurpose their vehicles’ Li-ION batteries. GM used Volt batteries to help their Enterprise Data Center become more energy independent. Nissan used Leaf batteries to help offset peak electricity demand. There are also a variety of small startups and student projects that are creating innovative uses for repurposed EV batteries including Freewire and Sunset Power.

But yes, eventually after these second, third, fourth life applications have all been exhausted, the battery reaches a point where it’s no longer useful and must be disposed of. At this point, 70+% can be recycled with current recycling processes, depending on the battery’s unique composition. What isn’t recycled is sometimes used as fuel in the furnace to melt down the valuable metals.

Lithium-ion battery recycling can result in zero waste to landfills, but is only economically feasible at high volumes. This super efficient recycling process will be profitable to recycling companies once there is a more steady input stream of Li-ION batteries for them to work with. This will come in just a few years once the first half million current EV adopters begin to retire their vehicles.

Interestingly, the most valuable metal to recycle in the Li-ION battery is not lithium. Nickel, cobalt, and iron are of much higher value, while lithium is actually cheaper to mine than to recycle. However, again the cost of lithium recycling will go down as recycling volumes increase.

Regulation will play an important role in battery recycling in the future, but currently lags behind the market. There are no clear federal regulations mandating a recycling process for Li-ION batteries from EVs. While widespread regulation is inevitably on the horizon, currently market forces and environmental activism are driving the private sector to invest in recycling Li-ION batteries.

The proper disposal of lithium-ion batteries is a valid concern. However, this new challenge is being met by the creation of a new and profitable market opportunity in Li-ION battery recycling, which will continue to increase efficiency in the battery recycling process, furthering the benefits of going electric.

Additional sources:
http://www.edmunds.com/fuel-economy/what-happens-to-ev-and-hybrid-batteries.html
http://www.greencitizen.com/recycling-lithium-ion-batteries/
https://www.tesla.com/blog/teslas-closed-loop-battery-recycling-program
http://www.pevcollaborative.org/