Discharge of NCA battery using copper strip in salt water

Abstract

The application of Li-ion batteries has been growing with the e-mobility revolution of computers, cellular phones and electric vehicles. As this revolution accompanies, manufacturers consider recycling wasted Li-ion batteries an important resource of raw material for manufacturing the lithium-ion battery. During the disposal, transport and crushing for recycling of the battery, it is necessary to crush for separation into black mass, plastic and metal parts, but there is a risk of explosion because of the residual voltage of the battery. Therefore, the discharge process is an important step in the recycling. This work aimed to investigate a new method to discharge the cylinder-type battery using salt water solution with the copper conductor that contacted and no-contacted with the battery. A gap value between the battery and copper conductor was a variable factor in the discharge process. The salt water called as electrolyte solution in the gap caused an electrical short circuit and accelerated discharging. During the discharge process, the battery cap and valve corroded when the battery did not come into contact with the copper conductor, causing the elements of the battery’s anode and cathode to dissolve into the solution. But, the voltage drop reached nearly 99%. However, the battery did not corrode when it contacted the copper during discharge, and the voltage drop reached approximately 90% after 8 hours with a 2 mm gap. Here, we report the battery discharge based on an electrochemical reaction, schematic diagram, and chemical analysis of the precipitate generated during the discharge test.