Non-destructive approach for upcycling the cathode of spent lithium-ion batteries: Combined with the efficient treatment of organic wastewater

Recycling spent lithium-ion batteries (SLIBs) has been a global research hotspot. However, its low-carbon development has received little attention. Traditional SLIB recycling through hydro/pyrometallurgy is heavily reagent-dependent and energy-consuming, posing high pollution risk. Here, we propose a novel strategy of recycling SLIBs coupling with organic wastewater disposal. Unlike traditional destructive recycling methods, this method takes advantage of the unique characteristics of SLBs such as pervasive defects and active sites to achieve novel utilization. We find that SLIBs show excellent catalytic performances for organic wastewater disposal in the peroxymonosulfate (PMS) activation system. Under optimal conditions of 0.2 g/L catalyst, 2 mM PMS, and initial pH = 7, the degradation rate of benzalkonium chloride exceeds 99 % at 40 min. Importantly, SLIBs also demonstrate efficacy against other typical pollutants, achieving nearly a 99 % degradation rate. The mechanism demonstrates that the redox of Co²⁺/Co³⁺ in SLIBs greatly accelerates the generation of reactive oxygen species, where SO₄⁻ and ¹O₂ are the main contributors for the catalytic degradation. In comparison to fresh Co₃O₄, SLIBs result in a 1.9-fold degradation rate constant. Our findings highlight potentials of recycling SLIBs coupling with other waste disposal and guide high-value utilization of SLIBs in a “treating waste by waste” way.