Environment

What happens to used lithium-ion batteries from electric cars?

Old standard batteries for domestic use contain harmful and environmentally hazardous substances, for example lead, mercury or cadmium. Therefore, you cannot just dispose of them in the household waste. If you want to dispose of batteries, you have several options in most countries. In supermarkets, for example, or at recycling centres, used batteries can usually be handed over free of charge. It's still not quite that simple with lithium-ion batteries from electric cars. In fact, there are already huge numbers of used traction batteries or rechargeable batteries being disposed of today.

Most car manufacturers recommend replacing the traction battery in an electric car after 8 to 10 years, some manufacturers even say 15 years. Since electromobility has only grown significantly in recent years, it may have been expected that it’d be a few more years before there would be a large number of batteries to dispose of. Yet waste management companies are already being overrun. "We’d never have thought that these quantities would have accumulated after such a short time," the managing director of a recycling company recently admitted, on behalf of his company. In the meantime, numerous companies are investing in battery recycling.

What happens to old lithium-ion batteries? In principle, there are two options: recycling the raw materials contained in the batteries and reusing the lithium-ion batteries that have been sorted out.

There's an increasing number of used lithium-ion batteries. After they’re used in electric cars, a part of the old batteries go through recycling to recover the raw materials they contain.

Battery recycling: from dismantling to melting down

The ADAC calculates that a battery weighing around 400 kilograms with a capacity of 50 kWh contains around 6 kg of lithium, 10 kg of manganese, 11 kg of cobalt, 32 kg of nickel and 100 kg of graphite. A wide variety of methods are used to recycle the raw materials. All of them aim to achieve the highest possible recycling rate. "A recycling process is efficient if it recovers at least 90 per cent of the target elements, such as graphite, lithium or cobalt," recycling expert Prof. Bernd Friedrich from RWTH Aachen University told the Automobile Club.

As a rule, recycling processes usually begin with manually dismantling the lithium-ion battery system. This is followed by other steps, such as sorting, shredding and thermal melting. According to the current state of the art, the majority of materials can be recycled today. However, some of the process steps still consume too much energy and are very expensive.

Numerous pilot plants have made it their mission to make the processes more efficient. The Volkswagen Group, for example, has set itself an ambitious long-term goal: the Wolfsburg company wants to recycle 97 percent of all raw materials. A pilot plant in Salzgitter aims to get this figure to 72 per cent from 2022.

Second life: Secondary use of lithium-ion batteries

Reusing batteries – also known as the "second life" method – is an exciting option, also because it is not possible for any recycling process to be completely free from residual materials. Here, the batteries continue to be used in stationary operation. Reusing batteries is particularly suitable because most batteries still have an energy content of 70 to 80 per cent of their original capacity when they’re sorted out.

Since the batteries are subjected to much less load in stationary operation, they can be used like this for well over 10 years. The sorted lithium-ion batteries are then used, for example, in private households or in industrial applications.

But even batteries that have been allowed to live a second life will face the last step at some point: the battery will be recycled.