Experimental study on catalytic pyrolysis of rape straw with the active cathode material of spent lithium-ion batteries and HZSM-5 as the tandem catalysts

Effect of calcination temperature on the chemical composition, porous structure of cathode materials of spent lithium batteries (lithium iron phosphate, LFP; lithium nickel-cobalt manganate, NCM), and the production of high value-added products in the catalytic pyrolysis of rape straw with active cathode materials and HZSM-5 as the tandem catalysts were studied. The X-ray difraction and N2 adsorption-desorption analysis revealed that Fe2O3 and Co1.29Ni1.71O4 were mainly included in the LFP and NCM cathode materials calcined at 600 °C (LFP600 and NCM600), and the BET surface area of LFP600 and NCM600 reached the highest of 11.41 m2/g and 24.10 m2/g. In terms of catalytic performance, both LFP600 and NCM600 cathode materials showed best bond-breaking effect. Comparing these two cathode materials, LFP600 exhibited the better bond-breaking effect, while NCM600 presented a good deoxygenation effect. Finally, the synergistic effect of active cathode material and HZSM-5 was studied, and the quantitative yield of benzene, toluene and xylene reached 11.41 wt% and 10.96 wt% with the optimized calcined cathode material and HZSM-5 mass ratio of 1:5. In this study, it provides a new way to make high-valued utilization of solid wastes like agricultural and forest residues and spent lithium battery to produce clean and renewable energy.