中南大学学报(自然科学版)2024,Vol.55Issue(11) :4332-4341.DOI:10.11817/j.issn.1672-7207.2024.11.028

退役锂离子电池超临界CO2剥离回收机制

Enhancement in exfoliation and recycling of lithium-ion batteries materials based on supercritical CO2 system

付元鹏 董宪姝 樊玉萍 马晓敏
中南大学学报(自然科学版)2024,Vol.55Issue(11) :4332-4341.DOI:10.11817/j.issn.1672-7207.2024.11.028

退役锂离子电池超临界CO2剥离回收机制

Enhancement in exfoliation and recycling of lithium-ion batteries materials based on supercritical CO2 system

付元鹏 1董宪姝 1樊玉萍 1马晓敏1
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作者信息

  • 1. 太原理工大学矿业工程学院,山西太原,030024
  • 折叠

摘要

通过自主试制超临界CO2(SC CO2)流体装置,利用超临界流体良好的溶解能力和传质特性提高锂电材料黏结体系在溶剂中的溶解率,提高电极材料高效剥离和回收效率.基于表面基团属性、颗粒团聚形貌及粒度分布特性对电极材料剥离及有机黏结剂的运移机制进行研究.研究结果表明:以二甲亚砜(DMSO)为共溶剂,在SC CO2系统温度为70℃、压力为8 MPa及时间为20 min试验条件下,电极材料的最佳解离效率达到96.7%;由于黏结剂从电极材料表面溶解脱除,并在CO2流体协同运移作用下与电极材料分离,因此,正极材料的团聚程度降低,活性电极材料得以分离回收.本文所提出的废弃电极材料回收工艺具有高效、环保的特点,符合电子废弃物循环领域绿色可持续发展要求.

Abstract

The supercritical(SC) CO2 was innovatively adapted to achieve efficient multi-component exfoliation and valuable component resource recovery from spent LIBs,based on improving the flow characteristics of high-viscosity solvent fluids through the use of the preferable dissolution and permeability properties of SC fluids.Based on surface group properties,particle aggregation morphology,and particle size distribution characteristics,the mechanism of electrode material detachment and organic binder transport was studied. The results indicate that the optimum experimental conditions for SC CO2 are a temperature of 70 ℃,a pressure of 8 MPa,and a duration of 20 min,with dimethyl sulfoxide(DMSO) as a cosolvent. Consequently,the liberation efficiency of the cathode increased to 96.7%. It is concluded that the binder is dissolved and removed from the surface of the electrode material,and is separated from the electrode material under the synergistic transport of CO2 fluid. Thus,after removing the organic binder,the agglomeration of the cathode decreased,and the cathode particles were dispersed into smaller fragments. The waste electrode materials recycling process in this article has the characteristics of high efficiency and environmental protection,which meets the requirements of green and sustainable development in the field of electronic waste recycling.

关键词

锂离子电池/正极材料/黏结体系/超临界CO2/解离

Key words

lithium-ion batteries/cathode material/bonding system/supercritical CO2/dissociation

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出版年

2024
中南大学学报(自然科学版)
中南大学

中南大学学报(自然科学版)

CSTPCD北大核心
影响因子:0.938
ISSN:1672-7207
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