The automotive sector is experiencing one of its greatest challenges to date, fighting against fossil fuels and pushing for electrification. The quest for a healthier environment requires specialisation in the industry and all related sectors. In this case, technological advances are not only applied to the production of cars, but also seek to go further. Generating a circular economy model within the automotive paradigm is one of the main objectives.
Electric vehicles will generate a waste that will be a challenge: lithium batteries recycle. It is expected that the recycling of batteries will increase in the coming years, as figures for 2020 show that the market share of electric vehicles in Spain was 22.5% and is growing steadily. The materials to be extracted from these batteries are lithium, cobalt, nickel or manganese, among other battery metals. Some of these elements have a high economic value and, in addition, mobile phones, computers, household appliances and more digital tools use these types of batteries.
The importance of lithium batteries recycling can be summed up in two clear objectives: the reduction of waste in the environment and the reuse of the recyclable materials that make up batteries to promote the circular economy.
How are lithium batteries recycled
To date, recycling techniques for these batteries are still under development and there is no industrial process in which primary lithium is recycled exclusively. Companies and research centres are trying to find methods for recycling batteries.
However, the methodology of lithium recovery (on a small scale) could be implemented as follows:
Reception and sorting of the discarded battery
Lithium batteries may appear to be different, but inside they all look alike. They are distinguished from each other by the composition of their cathode.
Discharge
Due to the electrical potential values of these batteries, a complete discharge is necessary, otherwise the Li+ ion could cause a reaction and lead to a fire or explosion. Depending on the battery, values of between 0.2-0.71 V can be distinguished at the time of discharge. Discharge is carried out by immersing the battery in a saturated sodium chloride solution for 24-48 hours, depending on the battery.
Separation
Once the discharge has been ensured (by measuring the charge potential with a tester), the cell is separated from its aluminium container, i.e., the cell is isolated in order to proceed to handle the electrodes (anode and cathode).
Sheets
Once the sheets are opened and unfolded, there is a copper anode covered with graphite, a permeable plastic polymer separator and a cathode made up of an aluminium sheet covered with a metallic oxide compound.
Recovery of raw materials
At this point, when everything is completely separated, the raw materials are recovered.
Anode
The anode is immersed in water with agitation and the graphite falls to the bottom of the vessel, leaving a clean copper sheet.
Cathode
The cathode is immersed in sodium hydroxide and causes the complete dissolution of the aluminium (leaching) and enables the decanting of the cathode material which, after filtering and washing, is ready to be treated. The cathode material is dried at 110 degrees Celsius for 24 hours and then calcined in a muffle at 700 degrees Celsius for 5 hours. The cathode material is subjected to acid leaching for dissolution.
Metal oxalates
After leaching, what remains is an acid solution rich in metals (cobalt, lithium, nickel, and manganese) to which oxalic acid is added to extract the oxalates from the different metals.
New batteries
Finally, the oxalates are chemically treated and the cathode materials are obtained ready for reuse.
In short, the new sustainable mobility requires the development of lithium battery recycling techniques to meet one of its basic objectives: caring for the environment and the planet. At ScrapAd, the platform for scrap metal trading, we believe that circular economy will play a fundamental role in the sector, generating new business opportunities in relation to recycling, which opens a whole range of possibilities.