Batteries may contain harmful metals and chemicals such as nickel cadmium, alkaline, mercury, nickel metal hydride and lead acid, which can contaminate the environment if not disposed properly. For example, when batteries containing cadmium is used in landfills, they will eventually dissolve and release the toxic substance that can seep into water supplies, posing serious health hazards for the population. This is why recycling batteries has become so important because it helps prevent pollution, and also saves resources.

First of all, the batteries to be recycled are sorted according to chemistries such as nickel-cadmium, nickel-metal-hydride, lithium, alkaline etc. The combustible material, such as plastics and insulation, is then removed with a gas fired thermal oxidizer, which is the first step in the recycling process. Most recycling plants have scrubbers where the gases from the thermal oxidizer are neutralized to remove pollutants, producing clean, naked cells that contain precious metal content.