Recycling hybrid car batteries is a topic that’s cropping up with regularity as more people switch to electrified vehicles. Toyota has been keen to ensure that when the third-generation Prius does reach the end of its useful life, it can be efficiently recycled.
At the end of its days, 85% of the Prius can be recycled and 95% of its materials can be recovered. This includes the hybrid system’s high-voltage battery, too, which is fully recyclable in a complex, but efficient and environmentally responsible process.
During the car’s life, the battery pack is responsible for storing the energy which is either recovered through regenerative braking or generated from the petrol engine, and supplying it on demand to the Hybrid Synergy Drive‘s powerful electric motor.
Storing and releasing a large amount of power in this way creates a lot of heat – the image below shows how the battery pack is cooled by a powerful fan.
The battery pack is designed to last the lifetime of Prius. When the car’s life is over, the battery will be removed at an authorised service centre.
From there it will be transported by a Toyota-appointed waste management company to one of three European final treatment companies, equipped to carry out the specialised recovery process that is at the heart of recycling hybrid car batteries.
The battery’s outer casing is stripped off and the metal re-used in steel-making. Likewise the wires and electronic parts are removed and handled by specialist recovery firms. This leaves the battery cells, which are subjected to high-temperature treatment while held in a vacuum sealed container.
At 400ºC all the organic materials break down into a mixture of oil and water, which is removed and processed by a licensed water treatment company.
The heat process continues to 800ºC, after which what remains of the cells is exposed to hydrogen, which helps break the oxides down into metals.
This leaves a highly concentrated nickel alloy that’s suitable for use as a raw material for making new batteries, completing a neat manufacturing circle. Other metals recovered at the end of the process are suitable for use in making stainless and other specialised steels.
The environmental impact of the complete recycling process was fully addressed in Toyota’s life cycle assessment of new Prius: In terms of the car’s lifetime CO2 emissions, the full recycling process is far from being a ‘dirty’ job – it’s responsible for only around 2% of the total.
Details in this article were correct at the time of publication.