What to know about… Second-life EV batteries
We need innovative uses for the millions of working lithium batteries that can no longer power electric vehicles (EVs) — and we’re getting them…
This article first appeared in the November 2023 issue of Air Quality News magazine.
Electronic devices have a single life. Generally, we use a phone or laptop until they stop working, then dispose of them. If a device still works but not as well as it used to, we might give it away second-hand – it might then have two owners, though still only one life.
However, a single life isn’t good enough when it comes to the lithium batteries used to power most electric vehicles (EVs). We need to understand why that it before we can dig into what can be done about it.
The lithium batteries used in EVs are generally the most expensive component of the vehicle. One reason is that you need a lot of lithium to power a car: an average EV battery contains 8 to 10kg but some EV batteries contain more than 60kg of lithium. The batteries also contain sizeable quantities of elements such as cobalt, copper and manganese. These might not be especially rare but they’re needed at considerable scale to service the fast-growing market for EVs.
For example, in 2022 there were just more than 1.6m new vehicle registrations in the UK. Of these, 267,203 were for battery-powered EVs and a further 581,406 were hybrid vehicles of some kind, making a total of 848,609 new vehicles – more than half of all new registrations – with some kind of battery inside. Given the average of 8 to 10kg per battery, that equates to between 6,800 and 8,500 tonnes of lithium in a single year, just in the UK. And the market is growing rapidly.
Sourcing enough lithium to meet demand is going to be a challenge. Then there’s the issue of batteries having a single life.
Photo by Kumpan Electric
All batteries wear out. Charging and recharging them affects the chemistry inside, over time reducing the amount of charge they can hold and ultimately stopping them working. Temperature can also affect performance, so particularly hot or cold days can be bad for batteries. The speed at which we recharge batteries is also an issue: faster charging makes the battery warmer, which in turn affects performance.
Lithium is especially resilient to such factors and lithium batteries used in EVs have a relatively long life. If you buy an EV today, its lithium battery will probably be guaranteed to retain at least 80% capacity for eight years or 100,000 miles. This is roughly the same time and distance that things start to go wrong with a car fuelled by petrol or diesel, so is more or less the average lifespan of conventional vehicles. Most drivers will simply replace their vehicle within this time frame. If you’ve made the switch to EVs, that means a new vehicle with a whole new guarantee of eight years’ high performance – perhaps more, given the rate at which technology advances.
But this also means that in 2030, the EVs bought in 2022 will come to the end of their guarantees. Some drivers might be happy to keep the same vehicle despite reduced performance. Others might be willing to buy a second-hand EV at a discount because of lower capacity. However, the expectation is that the majority of batteries will no longer be used in EVs once that initial guarantee elapses. That leaves us with more than 800,000 lithium batteries that have up to 80% of their capacity remaining.
One option is to recycle the old batteries to make new ones, which will help meet the demand for new EVs. This is easier said than done. Estimates suggest that in 2022 just 5% of lithium was being recycled. A major reason for this is that it’s currently much cheaper to source new lithium than to extract relatively small amounts of it (and other materials such as cobalt, copper, manganese and nickel) from complex battery components.
But that is liable to change in the next few years.
For one thing, the EU has ruled that from 1 January 2030, EV batteries must contain a minimum of reclaimed material, with 4% of all lithium used having been recycled. For another, industrial methods to recycle old batteries are improving very fast. The technique is to crush and shred the batteries, producing a waste product known as ‘black mass’ from which the lithium and other materials (copper, cobalt, manganese, nickel etc) can be more easily accessed. The UK’s first large-scale lithium-recycling plant opened in April 2023, with capacity to process up to 20,000 tonnes of batteries per year.
Black mass is currently a low-value byproduct and, as toxic waste, is subject to various controls. Yet, with rising demand for lithium, there is likely to be increased demand for black mass – and a corresponding rise in price. China and South Korea are well ahead in recycling black mass. In fact, China has even banned exports of its own black mass to other countries, recognising its value. Several industry bodies recently called for the EU to follow suit, to ensure access is retained to this needed feedstock.
But this isn’t the only way that EV batteries can have a second life. In the summer of 2023, Jaguar Land Rover announced plans for a battery energy storage system (BESS) comprising batteries that no longer have sufficient capacity to be used in EVs.
With up to 80% of their capacity still intact, these batteries can be used to store renewable energy from sources such as solar and wind.
This is significant because there have been challenges in connecting such renewable sources to the national grid. In some cases, renewable energy projects must wait a decade to be connected. Once connected, there may be limits on how much energy can be transferred at one time. The issue is that the national grid is not so much an energy store (ie a large battery) as a means of distributing energy. But the upshot is that some wind farms actually power down during windy periods because there isn’t sufficient local demand for energy and no means to share or store the excess.
Jaguar Land Rover isn’t the only company to see the potential for EV batteries to solve this mismatch. In September, Volvo Energy and Connected Energy announced plans for their own BESS system. UK Power Networks has even suggested that batteries still in use in EVs and parked in long-stay airport car parks could be used in a similar way, providing some 4.3GW of grid flexibility.
The extraordinary thought is that we can make such renewable sources more viable on a considerable scale, dramatically reducing our reliance on fossil fuels.
That would in turn mean less need to import such fuels, lowering costs and overall carbon footprint — all as a byproduct of EVs. Lithium batteries can be used in this manner until they reach a low threshold of capacity and can then be sent for recycling as black mass, ensuring we get the most value from this precious commodity.
In related news:
Opinion: Six key trends in the battery recycling market in 2023
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