Aqueous Ferrous Chloride as a Low-Cost Corrosive to Deal with Spent Coin-Type Cells

Abstract

The growing numbers of spent coin cells, especially those containing lithium metal, have become a cumulative burden in laboratories for worldwide research groups. The waste management of spent coin cells presents serious challenges: labor-costing manual disassembly and hazardous chemicals such as active lithium metal and side products such as hydrofluoric acid (HF). Here, we provide a solution to deal with spent coin cells by immersing them in a 0.5 M ferrous chloride (FeCl3) aqueous solution. The chlorides corrode the coin cell case that avoids the disassembly, while the moisture mildly and safely converts Li and HF into stable lithium hydrate (LiOH) and lithium fluoride (LiF). These one-week-treated coin cells can then be collected and stored, waiting for EH&S pick up. Our method is facile, labor-saving, cost-saving, and easily adapted to those who encounter the coin cell waste problem.