TiO2 recovered from spent selective catalytic reduction catalysts as anode material for lithium-ion batteries

Abstract

Environmental protection and sustainable development are among the most severe problems in the world today. Spent selective catalytic reduction (SCR) catalysts are recognized as hazardous waste. Here, the TiO2, which accounts for nearly 80% of spent SCR catalysts, is recovered by the alkaline leaching method, and performed higher electrochemical performances than commercial TiO2 products for anode materials of Lithium-ion batteries. W, V, Si, and Al leaching rates are 40.04%, 89.59%, 61.64%, and 11.57%, respectively. A combination of density functional theory (DFT)--based calculations and experiments revealed that trace doping of Al is beneficial to the electrochemical performance of the cell, which helps us tune the Al content in the obtained materials. On this basis, the regenerated TiO2 anode materials with graphene (GR) materials are synthesized to improve the electrochemical performance, and the specific capacity of the recycled TiO2 is 188.5 mAh·g−1 after 500 cycles, and that of the regenerated TiO2/GR is the highest at 275.2 mAh·g−1. Finally, an environmental assessment of this recycling process is also carried out, human toxicity potential, CO2 gas emissions, NMVOC gas emissions, and SO2 gas emissions in this work are reduced by nearly 86.9%, 87.0%, 92.5%, and 87.0% compared with commercial sol-gel synthetic method. This work highlights the significance of recovery for preparing new energy storage materials from secondary resources.