What happens to the spent batteries?

Even before 2020, demand for e-bikes was increasing by leaps and bounds every year. And the pandemic has only encouraged this development: To escape the cramped conditions of public transport and perhaps also to perform a "permitted" activity outdoors, many Swiss people acquired an e-bike. 171,132 e-bikes rolled across the sales counter in 2020. And the trend continues. More than 100 brands are already available, and a new company is entering the market every week or so.

Damaged or worn out: return to the point of sale

Much has already been written about the dangers posed by an e-bike battery. As long as the battery is attached to the bike, it is used regularly and the battery is charged according to the manufacturer's instructions, there is no reason to worry. It should be known that a damaged battery should be disposed of immediately. If a lithium-ion battery is crushed in an accident, for example, a short circuit can occur and the battery can catch fire. However, it is equally important that used batteries are not stored at home before they are disposed of. This is because if a battery is not used for a long time and its capacity falls below a certain minimum - a so-called deep discharge - there is a risk of a short circuit when it is reused. That is why rechargeable batteries that are no longer used should be disposed of as soon as possible. Thanks to the advanced disposal fee, which is included in the purchase price, rechargeable batteries can be handed in free of charge at any official point of sale of e-bikes or also at serviced disposal points of municipalities. This fee finances the collection, transport and recycling of the old batteries. The service life of an e-bike battery is about eight years. This means that most of the rechargeable batteries ever put into circulation are still in circulation. At the moment, however, over a hundred batteries are already being returned per day in Switzerland. In the next few years, this number is expected to multiply.

What happens after the collection point?

Discarded rechargeable batteries are processed in Switzerland by the company Batrec. To prevent lithium-ion batteries from igniting, they are first completely discharged by soaking them in salt water for several weeks. They are then shredded under water. The flammable electrolyte is washed away in the process. This is followed by mechanical processing: the aluminum and copper foils as well as the plastic are separated from the so-called black mass. In addition to graphite, which is responsible for the black color, this powder contains cobalt, nickel, manganese and lithium. These valuable materials are recovered at a sister Batrec plant. About 95 percent of the valuable substances cobalt and nickel can be recovered. Contrary to what the name suggests, a lithium-ion battery does not consist mainly of lithium, but only about 3 percent. This lithium ends up in landfills along with the other residues. Recovery would theoretically be possible, but it is not worthwhile because the primary raw material is currently much cheaper. If recycling volumes and the demand for lithium increase significantly in the next few years, this could soon change.

A new life

When an e-bike battery ends up in the recycling bin, it is not necessarily broken, but the storage capacity is too low for use in the bike - from about 40 percent. As stationary storage devices, however, these batteries are still perfectly adequate. Several batteries assembled together could thus be used in a second life as home storage for solar systems. More attractive, however, is to use used batteries from electric cars for this kind of second-life application. Numerous such storage systems are already in operation.

Another approach is to reuse individual cells from the used batteries. An e-bike battery consists of many small cells connected in series, which have the typical cylindrical shape of device batteries. If a single cell is defective, the entire battery stops working. The Swiss startup Libation is pursuing the goal of locating the cells that are still functional and using them to build new batteries. The challenge here is to test the cells in terms of degradation, capacity, safety and self-discharge. Such upcycled batteries are not yet ready for the market, but initial field tests have already been completed. Conceivable applications include small vehicles such as wheelchairs or cleaning vehicles.

In the coming years, the number of rechargeable batteries that end up in recycling will increase massively. It is to be expected that recycling and upcycling methods will undergo further technological development and that new business models will emerge.

 The article was written by Sara Blaser, GetArticle, c/o Sprachwerk GmbH, on behalf of Inobat created.