Rechargeable lithium ion based batteries power our tablets and phones they drive us from A to B in electrical based vehicles, and have numerous applications besides. Unfortunately, the devices that they supply power can fail and the batteries themselves are popularly only usable for three to two years.
As such, there are millions and millions of batteries that must be recycled. Research introduced in the International Journal of Energy Policy and Technology describes a novel technique to extract all the cobalt and the lithium that is used to make up the varying hefty metal components of these batteries.
According to Ataur Rahman of the Department of Mechanical Engineering, at the International Islamic University Malaysia and colleague in the Department of Economics, Rafia Afroz, explains that the price for both cobalt and lithium is rising. It is because the total demand for lithium ion batteries that need both of these metals for their construction and manufacturing are increasingly in demand. They have identified a recycling technology that can extract with reasonable efficacy the metals from scrap batteries.
The hydrometallurgical method of the group can recover both lithium and cobalt in their laboratory scale experiments from the standard 48.8 Wh lithium batteries. This involves first baking the battery in an oven at a temperature of 700 Celsius to ‘calcinate’ the copper, lithium, and copper components to destroy organic compounds, like foams and plastics.
The calcined substance carrying metal and metal compounds like oxides and salts is then treated with strong acid, sulphuric acid and hydrochloric acid, to leach out the metal ions. The entire group experimented with employing hydrogen peroxide as a reducing agent to witness whether that reagent would enhance the leaching process or not. They were able to extract the lithium with almost 50 percent efficacy and the cobalt with almost 25 percent efficacy.
Given that each of such metals represent 41% of the weight of a 48.8 Wh battery and around 8.5% of the weight, these are useful extraction rates that would on balance, given the heating and acid use, showcase a commercially viable method to recycling the electrodes from such batteries.
The leached metals could then be employed in the overall manufacture of novel batteries or elsewhere in the industry. The contaminated liquid waste could be further treated to make sure that it is safe for disposal under overall recycling regulations.
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