Safely avoiding the hazards of lithium-ion batteries

BHS-Sonthofen has upgraded its batteries recycling technology. ‘It reliably prevents fires and the release of hazardous gases, as the crusher process is kept gas-tight all the way until the dryer, which is where the electrolytes are evaporated,’ the company explains.

This process is suitable for lithium-ion car batteries as well as other household batteries. First, the input material is passed through a sluice to the gas-tight area before beginning the first process stage – crushing the battery. In the protective atmosphere, either one or two crushers are used: Single cell batteries and simple modules are ready to be processed further after one crushing stage, whereas larger batteries and battery packs as well as battery modules that have been screwed together undergo a two-stage crushing process.

The BHS rotary shear of type VR handles the pre-shredding process. This slow-speed twin-shaft crusher crushes bulky batteries and battery packs reliably with its interlocking blades. The stainless steel screws and the steel connectors between the modules pose no danger thanks to the protective atmosphere.

The pre-crushed fraction or input material from simple battery modules and cells is brought to the target size into in a single-shaft crusher during the main crushing step. The blade-equipped rotor of the BHS Universal Shredder of type NGU is perfectly suited for this stage.

For further processing, a batch dryer (type HTC) from AVA is used. ‘The dryer plays an important role in our process,’ comments BHS sales director Christian Kühn. ‘The electrolytes in the batteries can cause a fire. Furthermore, there are a lot of hazardous materials in the batteries. There is a risk of toxic dust explosions. We avoid these risks to people and the environment with the HTC and the protective atmosphere.’

There is a material buffer between the continuously operating Universal Shredder and the dryer – also in the system’s gas-tight area – for systems with larger capacities. After filling, the dryer applies a vacuum of around 400 millibars and slowly heats the input material to 110°C.

The crushed batteries are no longer hazardous after the drying phase. BHS plans to expanded this process in the future, Kühn says. ‘Our engineers are constantly working on refining the recycling process for batteries, in particular. We are currently testing concepts for discharging batteries and possibilities for further chemical treatment of the black mass.’