Electrochemical recycling of cell phone Li-ion batteries: application as corrosion protector of AISI 430 stainless steel in artificial seawater

This article aims to present a new alternative to waste management of spent Li-ion batteries from cell phones. In this sense, the proposed is recycling the cobalt from Li-ion cathode by electrodeposition and apply it as corrosion protector of AISI 430 stainless steel. Thus, two greatest environmental problems can be solved, producing a low-cost and high-corrosion-resistant stainless steel. The cobalt electrodeposition bath came from acid dissolution of spent Li-ion cathode with chemical formula LiCoO2. The charge efficiency for cobalt electrodeposition in −1.0 V and pH = 3 reaches 95 %. A protective layer of Co3O4 was successfully obtained by treatment of AISI 430 stainless steel with cobalt electrodeposited at 800 °C for 200 h in air atmosphere. The corrosion current of AISI 430 stainless steel in artificial seawater was reduced from 30 to 0.76 μA cm−2. The treatment proposed produces a AISI 430 stainless steel with double of corrosion resistance and half of cost if compared with AISI 304 stainless steel.