文章信息/Info

Title:

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

文章編號:

1674-3962(2024)05-0369-05

作者:

閆姝璇; 劉洪博; 陳湘萍; 楊鷹; 周濤

1. 中南大學化學化工學院，湖南 長沙 410000 2. 湖南師范大學化學化工學院，湖南 長沙 410000

Author(s):

YAN Shuxuan;  LIU Hongbo;  CHEN Xiangping;  YANG Ying;  ZHOU Tao

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

關鍵詞:

退役鋰離子電池; 生物質裂解; 熱化學過程; 有價金屬; 選擇性分離

Keywords:

Spent lithium-ion batteries;  Biomass pyrolysis;  Thermochemical process;  Valuable metal;  Selective separation

分類號:

TF803；TQ09

DOI:

10.7502/j.issn.1674-3962.202308002

文獻標志碼:

A

摘要:

鋰離子電池日前的爆發式增長使之將在未來的3～5年內面臨大量的“退役”問題。退役鋰離子電池尤其是退役正極材料的高效、可持續的回收利用，是實現新能源產業碳達峰和碳中和目標的關鍵。主要研究了玉米秸稈對退役正極材料LiNi1/3Co1/3Mn1/3O2(NCM333)中有價金屬的熱化學還原過程，通過調控轉化高價金屬，選擇性回收金屬鹽及單質，避免傳統回收過程中化學試劑的添加，同時利用退役正極材料中的過渡金屬特性，對玉米秸稈進行催化重整產氣。使用X射線衍射儀、X射線光電子能譜等儀器分析熱解后的正極材料和玉米秸稈，結果表明，玉米秸稈熱解、氣化產生的還原性氣體和生物碳破壞了正極材料LiNi1/3Co1/3Mn1/3O2中的高價金屬—氧鍵，降低Ni，Co和Mn的金屬價態，同時將Li轉化為Li2CO3。不同的熱解溫度得到了不同的熱解產物，較高的溫度更易得到Ni-Co合金及MnO。熱解還原過程中正極材料中的過渡金屬對玉米秸稈熱解來說是良好的催化劑，可以降低熱解反應的所需溫度，提升碳熱反應的可能性，從而實現“廢物+廢物=資源”的目的。該工藝可以在不外加還原劑的情況下高效、高選擇性和無污染地梯度回收有價金屬，不僅提供了一條綠色可持續發展的退役鋰離子電池回收路徑，也為生物質的催化重整提供了一種成本低廉的催化劑的選擇。

Abstract:

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.