At a low-rise, red-brick plant next to the sea in Oskarshamn, Sweden, Saft is doing something unique in the battery industry. The plant, built more than a century ago, makes high-performance industrial nickel-cadmium (Ni-Cd) batteries, using wherever possible, material extracted on the same site from spent batteries.
“This site has been making batteries since 1915 and has been recycling them since before the Second World War,” explains Mari Kadowaki, general manager of the plant. “It’s a complex process that has developed over time and the recycling technology we use today is based on technology developed in-house in the 1970s and 80s, specifically for Ni-Cd batteries.”
While care is needed when dismantling any battery, for Ni-Cd batteries the process is particularly complex. The way the nickel, cobalt and cadmium are attached to the electrodes demands an industrial process to remove them safely.
“They are a challenge to recycle safely and well,” says Kadowaki. This may explain why the Saft plant is the only one worldwide to be involved in both the recycling and manufacturing of Ni-Cd batteries. Other plants focus on either recycling or producing.
Saft operates a network of over 30 bring back points worldwide that receive spent Ni-Cd batteries made at Oskarshamn and at its Bordeaux plant, as well as those made by its competitors. To minimize transportation, the bring back point located in northern Europe brings these used batteries back to Oskarshamn. Other bring back points work with other fully permitted recycling partners selected by Saft.
Global regulations covering the recycling of batteries differ by jurisdiction, but because of the plant’s location, Saft follows those governing the European Union. As demand for batteries increases as part of the transition away from fossil fuels, the EU is updating its battery legislation to increase the efficiency and the metal recovery rates of recycling processes.
Under the existing 2006 battery directive, “we have to recycle at least 75 per cent of the weight of a battery” Kadowaki says. “This is quite challenging and we must always ensure our processes work super efficiently!”
The plant today focuses on industrial Ni-Cd batteries. “As we produce Ni-Cd here it makes sense economically and environmentally to use our capacity to feed our reclaimed materials into that production process,” she says.
In a standard pocket plate Ni-Cd battery of the type produced and recycled at Oskarshamn, the largest components by weight are the electrodes.
Oskarshamn reclaims the nickel, cobalt and cadmium for reuse onsite, while the other metals it reclaims such as steel and copper as well as the plastic containers are sent to third parties for recycling. The plastic containers, which used to be burnt for energy, are cleaned to be used in injection molding for example. Whereas the electrolyte is purified on site. “When we’ve finished processing the electrolytes, the remaining metal levels are lower than the legal thresholds imposed on drinking water,” Kadowaki reveals.
Besides its excellent record of recycling, the battery production plant itself has an impressive set of eco-credentials. According to Kadowaki, direct emissions are virtually zero and it uses as little energy and water as possible. In fact, the plant today uses the same amount of energy it did 30 years ago to produce six times more batteries.
Looking to the future, Saft is working to ensure that the recycling process is as efficient as possible. This means design teams are looking at how much material can be reclaimed and how the dismantling process will wear the machinery used and the level of dust that will be created, for example. As production increases, Saft is also looking to increase its recycling capacity. While this means extra investment, for Saft it is seen as a cost of doing business. “As an industrial battery-maker we are fully responsible for recycling. It’s the right thing to do,” says Kadowaki.