Over 25,000 pure electric cars were sold between January and September 2019. Doesn’t sound like much, but that’s a rise of 122% on the same period in 2018, and numbers of battery cars – pure electric, plug-in hybrid and full hybrid alike – look set to continue the rapid rise. Where will all the used electric vehicle batteries go? While this is an environmental win on most counts, there is an often-overlooked ecological burden associated with them: the batteries. What do we do with them when they reach the point that they need to be re-used or recycled?

One popular solution is to re-use them as power storage for domestic and commercial buildings. Nissan specialises in this, and has even installed second-hand Nissan Leaf batteries as a huge back-up generator for an arena in Amsterdam; the largest power storage facility in Europe.

On a smaller scale, Nissan also offers a power storage unit called xStorage that does the same job for home or domestic use, meaning that you can install it in conjunction with solar panels, and use the battery storage to charge your car or other utilities at peak hours, thereby offering green energy and also saving you money and reducing strain on the national grid.

Even so, energy storage is far from a one-shot solution for the used EV battery issue. Some don’t think it’s a solution at all.

Transport applications require a very energy-dense battery to provide the necessary range from a comparably small cell. To achieve that small-but-powerful combination requires large quantities of cobalt and lithium in the lithium-ion batteries that are the chief technology powering electric cars today.

The mining of cobalt is a critical issue in battery production. Much of it is sourced from the Democratic Republic of Congo, where the mining process raises serious ecological and human rights concerns. Reducing dependency on it as demand for batteries rise, and making best use of the cobalt already in circulation, is a critical factor in battery production and re-use.

Dr. Gavin Harper, a Faraday Institution Research Fellow at the Birmingham Energy Institute’s project on Recycling and Reuse of Lithium Ion batteries (ReLiB), stated that “if we face constraints around cobalt, some feel we should focus this precious resource on more demanding applications such as EVs. It may make more economic sense to recycle EV batteries for use in brand new batteries for cars, rather than using them in a used state in a less demanding application such as power storage.”

Another significant consideration for EV batteries is the recycling process. Belgium-based company, Umicore, already offers recycling for lithium-ion batteries. The plant can currently recycle around 35,000 EV batteries per year and, according to a company spokesperson, “can easily scale up its recycling activities when the market grows, which we expect to happen in 2025.”

Even better, metals are infinitely recyclable, so they can be reclaimed from used batteries and used to produce new batteries that are as good as any other.

It’s heartening to know the technology needed to reclaim and recycle batteries – including the precious metals and plastics in the casing – already exists. In fact, it’s estimated that electric car batteries are already 90% recyclable.

But there are many areas for improvement, including the way we reclaim and transport damaged batteries. The electrolyte in batteries is highly volatile and makes the removal, transport and storage of used cells potentially hazardous. Working on ways to safely and efficiently manage this is one of the most critical aspects of successfully managing the quantity of batteries that will need to be recycled or re-used.

Another consideration is changing battery tech. Solid-state batteries have been mooted as a possible next-step in batteries for many years, and some manufacturers are now stating that they could be a cobalt-free electric car battery solution good enough for mass market sale by 2025.

This tech has great potential to reduce the environmental impact of battery production, and also promises less volatile battery chemistry, but what of their recyclability?

According to Peter Slater, Professor of Materials Chemistry and Co-director of the Birmingham Centre for Energy Storage, solid state batteries “can be recycled but they would present different challenges in terms of separating the components. In particular, it is likely that it would need chemical separation routes rather than pyro-metallurgical process more commonly used now.”

Ultimately, if the appalling environmental implications of putting batteries into landfill isn’t persuasive enough, the other cold truth is that batteries and the metals they contain – regardless of whether it’s lithium-ion, solid-state or otherwise – are too valuable to waste. In essence, there’s serious money to be made in used car batteries.

So, while there are many and varied answers to the question of ‘where will the used EV batteries go?’, ecological and economic good reason are in agreement on this one: not into the ground.

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