Freezing Solution for Battery Recycling
Electric vehicle manufacturers are expanding their production capacity to electrify the vehicle market as soon as possible. Therefore, more batteries will be produced, and those batteries will become hazardous waste when they reach their end of life. Additionally, raw materials prices surge, and supply chains lag due to military conflicts and slow mining methods. Hence, Companies are attracted to the battery industry for all these reasons.
Posco Group, South Korea's biggest steel manufacturer, has produced active battery material for two years. In 2030, Posco will increase its cathode material capacity to 610,000 tons and anode material capacity to 322,000 tons. Moreover, Posco would also produce 300,000 tons of lithium and 220,000 tons of nickel. Posco has opened its recycling facility in Poland as part of its supply chain strengthening plan.
In order to recycle lithium-ion batteries, the cells must be crushed into scraps. However, all cells are not charged at the same rate. In this way, crushing them produces a short circuit, exposing flammable electrolytes to the environment and causing a fire. Therefore, it is necessary to fully discharge the cells before crushing them. It takes about 8 hours to discharge the cells in a battery pack. It should be mentioned, in addition, that the hydrogen ions and fluoride ions released from the electrolyte can combine and turn into a highly harmful gas, hydrogen fluoride (HF).
Posco has introduced a comprehensive solution to address the problems mentioned above. In this method, battery cells are frozen before they are crushed. The freezing step reduces the battery voltage to zero, and the liquid electrolyte solidifies, avoiding the time-consuming discharge process and preventing hazardous gas releases. It is necessary to cool battery cells to -80°C by using inert gases such as carbon dioxide, argon, nitrogen, or a combination of these gases. When the pressure is adjusted to a vacuum atmosphere of 100 Torr, the electrolyte is prevented from reacting with oxygen and causing an explosion. A further benefit is that it prevents the evaporation of the electrolyte, preventing the generation of flammable gases like ethylene, propylene, and hydrogen.
Battscout has reviewed the latest recycling methods, like direct recycling or extracting metallic nickel instead of sulfates and oxides, that companies like Tesla or U.S. national laboratories applied.