Lithium and Calcium recovery by activated carbon from coconut shell char

Spent rechargeable batteries and electronic waste become a future challenge. The precious metal inside should be recovered for pursuing a circular economy society. Here, lithium phosphate battery has been dismantled and leached the cathodes by acidic solution to produce metal solutions. The metal content will be separated by a simple adsorption mechanism using activated charcoal. Coconut shell char has been activated by KOH in several temperature settings and then tested to adsorb lithium and calcium ions in the leaching solution. The capacity of adsorption and selectivity between the ions were investigated. The adsorption capacity is strongly related to the activation temperature and KOH/char ratio. Higher activation temperature and agent ratio tend to provide better-activated carbon for metal ion adsorption. It is found that Li ions have lower affinity toward the surface of carbon especially in low concentration than Ca ions. © Published under licence by IOP Publishing Ltd.