1.College of Chemistry and Chemical Engineering, Central South University，Changsha 410000，China
2.College of Chemistry and Chemical Engineering, Hunan Normal University, Changsha 410000，China
The recent explosive growth of lithium-ion batteries will face a large number of “decommissioning” problems in the next 3 to 5 years. The efficient and sustainable recycling of spent lithium-ion batteries, especially waste cathode materials, is the key to achieving the goal of carbon peak and carbon neutrality in the new energy industry. This paper mainly studies the thermochemical reduction process of valuable metals in waste cathode materials LiNi1/3Co1/3Mn1/3O2 by corn stalks. Through regulating and transforming high-valence metals, selective recovery of metal salts and elemental substances avoids the addition of reducing agents in the traditional process and utilizes the transition metal characteristics in waste cathode materials for catalytic reforming of corn stalk to produce gas. During the reaction process, X-ray diffraction and X-ray photoelectron spectroscopy were used to analyze the cathode material and corn straw after pyrolysis. It was found that the reducing gas and biological carbon generated by the pyrolysis and gasification of corn straw destroyed the high-value metal-oxygen bond in the cathode material LiNi1/3Co1/3Mn1/3O2, and reduced the metal valence states of Ni, Co and Mn. It also converts Li to Li2CO3. Different pyrolysis products are obtained at different pyrolysis temperatures, and Ni-Co alloy and MnO are easier to be obtained at higher temperatures. In the process of pyrolysis and reduction, the transition metal in the positive electrode material is a good catalyst for the pyrolysis of corn straw, which can reduce the required temperature of the pyrolysis reaction, improve the possibility of carbothermal reaction, and regulate the gas composition generated by pyrolysis, so as to achieve the purpose of “waste+waste=resources”. The process can recover valuable metals in an efficient, highly selective and pollution-free gradient without reducing agents addition, which not only provides a green and sustainable recycling path for spent lithium-ion batteries, but also provides a low-cost catalyst for the catalytic reforming process of biomass.