Recycling Co and Li from spent lithium-ion batteries with the pyrolysis gases of retired photovoltaics panels

Abstract

Large-scale installations of lithium-ion batteries (LIBs) and photovoltaics (PV) modules have been continuously accelerating in recent decades, and the resultant challenge of how to cope with the waste LIBs and PV panels is initially emerging. Here we utilize the pyrolysis gases of the waste PV modules to reduce the LiCoO2 obtained from the waste LIBs. During pyrolysis, nearly 85–95 wt% of waste PV back sheet is decomposed into reducing gases (CO, CH4, C2H4) at 500 °C. With the assistance of these gases, waste LiCoO2 can be reduced and transformed to water-soluble Li2CO3 and water-insoluble CoO/Co. A high Li recovery rate of 98.5 % is achieved after a 5-min roasting process at 500 °C in a closed reactor. The optimal mass ratio of TPT back sheet to LiCoO2 is closed to 1: 1. Hence, this research offers a sustainable, high-efficiency, and industry-feasible technology for the extraction of Li and Co coupling with the dismantling of the waste PV models and thereby contributing to the ease of Li supply crisis as well as the circular economy of the LIBs and PV system.