退役NCM333正极材料热化学还原转化过程研究  

Thermochemically Regulated Conversion Recovery Processes of NCM333 in Spent Lithium-Ion Batteries

作　　者：闫姝璇 刘洪博 陈湘萍 杨鹰[1] 周涛[1] YAN Shuxuan;LIU Hongbo;CHEN Xiangping;YANG Ying;ZHOU Tao(College of Chemistry and Chemical Engineering,Central South University,Changsha 410083,China;College of Chemistry and Chemical Engineering,Hunan Normal University,Changsha 410081,China)

机构地区：[1]中南大学化学化工学院,湖南长沙410083 [2]湖南师范大学化学化工学院,湖南长沙410081

出　　处：《中国材料进展》2024年第5期369-373,407,共6页Materials China

基　　金：国家自然科学基金面上项目(52174391)。

摘　　要：锂离子电池日前的爆发式增长使之将在未来的3~5年内面临大量的“退役”问题。退役锂离子电池尤其是退役正极材料的高效、可持续的回收利用,是实现新能源产业碳达峰和碳中和目标的关键。主要研究了玉米秸秆对退役正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)(NCM333)中有价金属的热化学还原过程,通过调控转化高价金属,选择性回收金属盐及单质,避免传统回收过程中化学试剂的添加,同时利用退役正极材料中的过渡金属特性,对玉米秸秆进行催化重整产气。使用X射线衍射仪、X射线光电子能谱等仪器分析热解后的正极材料和玉米秸秆,结果表明,玉米秸秆热解、气化产生的还原性气体和生物碳破坏了正极材料LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)中的高价金属—氧键,降低Ni,Co和Mn的金属价态,同时将Li转化为Li_(2)CO_(3)。不同的热解温度得到了不同的热解产物,较高的温度更易得到Ni-Co合金及MnO。热解还原过程中正极材料中的过渡金属对玉米秸秆热解来说是良好的催化剂,可以降低热解反应的所需温度,提升碳热反应的可能性,从而实现“废物+废物=资源”的目的。该工艺可以在不外加还原剂的情况下高效、高选择性和无污染地梯度回收有价金属,不仅提供了一条绿色可持续发展的退役锂离子电池回收路径,也为生物质的催化重整提供了一种成本低廉的催化剂的选择。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 LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2)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 metaloxygen bond in the cathode material LiNi_(1/3)Co_(1/3)Mn_(1/3)O_(2),and reduced the metal valence states of Ni,Co and Mn.It also converts Li to Li_(2)CO_(3).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-c

关 键 词：退役锂离子电池 生物质裂解 热化学过程 有价金属 选择性分离 

分 类 号：TF803[冶金工程—有色金属冶金] TQ09[化学工程]