基于高效回收废旧锂离子电池正极材料的低共熔溶剂的筛选  

Screening of Deep Eutectic Solvent Based on Efficient Recovery of Spent Lithium⁃ion Battery Cathode Materials

作　　者：巩珊珊 吴彤[1] 王官格 黄擎 苏岳锋[1,2] 吴锋 GONG Shanshan;WU Tong;WANG Guange;HUANG Qing;SU Yuefeng;WU Feng(School of Materials Science and Engineering,Beijing Institute of Technology,Beijing 100081,China;Beijing Institute of Technology Chongqing Innovation Center,Chongqing 401120,China)

机构地区：[1]北京理工大学材料学院,北京100081 [2]北京理工大学重庆创新中心,重庆401120

出　　处：《高等学校化学学报》2021年第10期3151-3159,共9页Chemical Journal of Chinese Universities

基　　金：国家重点研发计划项目(批准号:2016YFB0100301);国家自然科学基金(批准号:21875022,51802020,U1664255)资助.

摘　　要：针对废旧锂离子电池(LIBs)回收过程中产生的二次污染及高能耗等问题,提出了一种绿色高效浸出废旧LIBs正极材料中有价金属的新方法.以氯化胆碱和不同的氢键供体(草酸、丙二酸、戊二酸和苯磺酸)为原料,合成了氯化胆碱/酸二元低共熔溶剂(DES)、氯化胆碱/酸/水和氯化胆碱/酸/乙醇等三元DES.通过傅里叶变换红外光谱(FTIR)和核磁共振波谱(NMR)表征了氯化胆碱和酸之间氢键的形成过程,探究了DES中羧酸的烷基链长、酸性大小以及添加水和乙醇组分对浸出废旧LiCoO_(2)正极材料的影响.研究结果表明,羧酸烷基链长的增加会使DES的浸出能力下降;酸的酸性大小不能作为溶解金属氧化物能力强弱的主要依据;加入等摩尔量的水对DES的浸出效率影响较小,而等摩尔量加入无水乙醇会影响DES的氢键结构,对浸出结果影响较大.筛选出氯化胆碱/苯磺酸/乙醇DES作为废旧LiCoO_(2)绿色高效的浸出剂,Li和Co的浸出效率分别高达98.6%和95.2%.To resolve the secondary pollution and high energy consumption caused by the recycling of spent lithium-ion batteries(LIBs),a green and efficient method for leaching valuable metals from spent LIBs cathode materials is developed.Choline chloride and different hydrogen bond donors(oxalic acid,malonic acid,glutaric acid and benzenesulfonic acid)were used to synthesize choline chloride/acid binary deep eutectic solvent(DES),chlorine choline/acid/H2O and choline chloride/acid/ethanol ternary DES.The formation process of the hydrogen bond between choline chloride and acid was characterized by means of Fourier transform infrared spectroscopy(FTIR)and nuclear magnetic resonance spectroscopy(NMR).The impacts of carboxylic acid alkyl chain length,acidity and addition of water and ethanol on the leaching of spent LiCoO_(2) were investigated.The results show that the leaching capacity of DES decrease with the increase of the carboxylic acid alkyl chain length.The acidity of the acid cannot be concluded as the main reason for the higher ability to dissolve metal oxides.The equimolar addition of water has little effect on the leaching efficien⁃cy of DES,while the equimolar addition of ethanol will affect the hydrogen bond structure of DES,which has a greater impact on the leaching efficiency.At last,choline chloride/benzenesulfonic acid/ethanol DES was screened as a green and efficient leaching agent for spent LiCoO_(2),leaching efficiencies of Li and Co were as high as 98.6%and 95.2%,respectively.

关 键 词：低共熔溶剂 氢键 废旧锂离子电池 高效回收 

分 类 号：O646[理学—物理化学]