Lead is one of the most sustainable raw materials on the planet. Recycling is more energy-efficient than mining and smelting new lead. The lead from a dead battery can be refined into new alloy over and over again making much better use of existing resources. Its sustainability is unmatched and serves as a buffer to raw material price fluctuations that could compromise the practicality of commercial use. The supply of lead is not dependent on one dominating international source, unlike material used in some other forms of energy power storage.
The process begins with the used battery being broken apart with a machine that hammers the it into many pieces. The pieces are placed into a vat, where lighter plastic floats and all other materials sink to the bottom. The pieces are separated into three parts, the plastic, lead, and battery acid. The polypropylene plastic bits are washed and dried, then sent to a plant to be melted and formed into pellets, which are sold to battery manufacturers for use in new batteries. The lead parts are heated in a furnace until molten. Impurities in the lead float to the top and are removed. The remaining lead is sent to manufacturers for use in new batteries. Old battery acids are treated with a base solution that neutralizes them and turns the acid into water that is tested for safety, then reused. A small portion of the acid is processed into sodium sulfate, used in many manufacturing processes, in glass and in laundry soaps.