Etching‐Expanded Anode: A Method to Improve the Reduction Efficiency of Vacuum Thermal Reduction of Spent Anode to Spent Ternary Cathode

Vacuum carbon thermal reduction has been widely studied for the recovery of ternary lithium batteries, and there are many choices for the type of carbon to be reduced in this method, such as expensive carbon nanotubes and inexpensive battery anode carbon. In this paper, the vacuum reduction of ternary lithium batteries cathode materials by carbon nanotubes was investigated, and it was confirmed that carbon nanotubes, as a high‐quality carbon with high carbon content and large specific surface area can achieve very excellent reduction results. Using concentrated sulfuric acid with a concentration of 98% and H 2 O 2 with a concentration of 60%, swollen anode carbon as the reduced carbon, the direct yields of Li and Mn were above 99% at a vacuum of 10 Pa, a temperature of 1623 K, a pressurized material pressure of 0 MPa, and a roasting time of 90 min, similar to the effect of expensive carbon nanotubes, and the roasting time was lower than that of the unetched anode carbon. This process improves the reduction efficiency and saves energy consumption in vacuum carbon thermal reduction of waste ternary lithium batteries cathode materials.