What happens to an EV battery after it's removed from your car?

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An EV battery's life is far from over once it leaves a car. When the owner is done with the vehicle, for whatever reason, there are varying degrees of battery health and usefulness to consider. It may not be able to supply the original range any longer, may have developed a fault or it could have been damaged in a crash. But even if a car owner decides it's time to replace their EV battery, the battery still has more to offer, and specialists (usually called EV battery diagnosticians or technicians) will inspect, test and determine what comes next in the battery's lifecycle.

Occasionally, repair is possible. An EV battery pack contains several individual cells, typically grouped in modules. Depending on the design, a tech may be able to replace a module or component, instead of tossing the entire thing into the recycling or repurposing pile. A safe and reliable used EV battery can potentially be reused in a compatible vehicle. However, it doesn't always work out that way because some EV packs are really difficult to repair, especially if the vehicle was in a particularly nasty accident, the kind that results in a total loss. 

For the most part, an EV battery will enter a repair or reuse operation post-removal. Its condition will determine its future, whether it becomes stationary energy storage or goes to a recycler. There's no singular answer here, only a list of possibilities, depending on the battery's status.

Just because an EV battery no longer delivers the range the owner wants doesn't mean it's no longer useful. Retired EV batteries can potentially retain as much as 70 to 80 percent of their original capacity, assuming they aren't damaged. Basically, it boils down to what it can be used for next. Pretty simple, really. One of the popular options is placing them in stationary energy storage. Instead of powering an EV, it supplies backup power for a building or helps balance electricity supply and demand on the grid. For example, California is using Nissan Leaf and Honda batteries to store solar energy. 

Though the battery's commute is long over, the work goes on. Repurposing isn't always a simple process, however. Once a tech has thoroughly inspected the battery, they integrate suitable components and any controls and safety equipment needed for its new or future home. It's a costly process as well, so there's no guarantee that a viable battery won't face recycling if the cost is more than the return.

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Repair and repurposing are nice, but neither is suitable in some cases. Fortunately, that doesn't spell the end of an EV battery's usefulness. If repair or repurposing aren't on the docket, the pack is prepared for safe processing and dismantled. Materials like steel, aluminum and copper are stripped out and recovered. Cell processing typically involves shredding and separation that produces a mixture of "black mass." This black mass contains electrode materials that will eventually go through even more processing to recover valuable ingredients.

The battery's chemistry dictates the next stage, which may include heat or chemical solutions to extract more. Since not all batteries are identical, the outcomes will include varying amounts of material, most of which will return to manufacturing. Again, the recycling process is costly. It requires a lot of energy and results in losses during the procedure. But it does result in less demand for mined resources, which means less environmental impact.