Modulating ORR/OER/IRR trifunctional catalysis via ultraviolet activation of recycled carbon black for lithium-ion batteries

Abstract The recycling of spent lithium-ion batteries (LIBs) is crucial for the sustainable utilization of metal resources. However, challenges such as range anxiety hinder its widespread adoption, thereby driving the pursuit of next-generation energy storage systems with higher energy densities. In this study, we report the development of a trifunctional electrocatalyst, URCA-800, derived from recycled carbon black obtained from ternary LIB cathode materials. The activation process involved vacuum ultraviolet (VUV) irradiation in the presence of melamine as a nitrogen source, enabling effective N-doping and structural modification. Following calcination at 800 °C, the resulting URCA-800 catalyst exhibited enhanced electrocatalytic performance toward the oxygen reduction reaction (ORR), oxygen evolution reaction (OER), and iodine reduction reaction (IRR). Specifically, URCA-800 achieved an ORR half-wave potential of 0.80 V (vs. RHE) and an OER overpotential of 363 mV at a current density of 10 mA cm − 2 in 0.1 mol L − 1 KOH, comparable to the performance of commercial Pt/C and IrO 2 catalysts. When applied as a cathode in zinc-air batteries, URCA-800 delivered a high-power density of 196 mW cm − 2 and demonstrated excellent operational stability exceeding 400 h. Furthermore, in zinc-iodine batteries, it achieved a high specific capacity of 188.8 mAh g − 1 , an impressive iodine utilization efficiency of 89.6%, and outstanding cycling stability over 3,400 cycles. This work presents a scalable and environmentally friendly approach to convert battery waste into high-performance, multifunctional electrocatalysts, offering a promising pathway for advanced energy storage technologies.