Selectively peeling of spent LiFePO4 cathode by destruction of crystal structure and binder matrix for efficient recycling of spent battery materials
Selectively peeling of spent LiFePO4 cathode by destruction of crystal structure and binder matrix for efficient recycling of spent battery materials
复制标题
通过破坏晶体结构和粘合剂基质选择性剥离废旧磷酸铁锂正极，以实现废旧电池材料的高效回收
DOI：
10.1016/j.jhazmat.2019.121633
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发表时间：
2020-03-15
影响因子：
13.6
通讯作者：
Zhang, Fu-Shen
中科院分区：
文献类型：
--
作者：
He, Kai;Zhang, Zhi-Yuan;Zhang, Fu-Shen
杂质Fe会严重损害合成正极材料的性能，因此，LiFePO 4正极材料必须从混合废锂离子电池中去除，以实现材料的回收利用。在这项研究中，非湿法冶金方法已经开发出的选择性剥离的LiFePO 4正极材料和剥离过程很好地解释了理论模型。LiFePO 4的剥离效率接近100%，而LiMn 2 O 4/LiCoO 2/Li（Ni，Co，Al）O2-/Li（Ni，Mn，Co）O2-的剥离效率仅为0.08%。也就是说，分离选择性为1250。剥离机理研究表明，剥离是通过选择性破坏LiFePO 4晶体和聚偏氟乙烯（PVDF）粘结剂基体实现的。特别地，LiFePO 4的晶体结构首先被硫化物破坏，因此LiFePO 4颗粒从PVDF粘结剂基体中脱离。然后，由于机械强度减弱，未填充LiFePO 4颗粒的PVDF粘合剂更容易被铝箔与水反应产生的氢的微爆力脆性剥落。该方法适用于回收各种类型的废LIB，具有很强的工业应用潜力。
Impurity Fe could severely damage the performance of resynthesized cathode material, and therefore, LiFePO4 cathode should be removed from the mixed spent LIBs for materials recycling. In this research, a non-hydro metallurgy method has been developed to separate LiFePO4 by selectively peeling-off the LiFePO4 cathode material and the peeling-off process was well explained by theoretical modeling. The peeling-off efficiency of LiFePO4 was approximate 100 % and that of LiMn2O4/LiCoO2/Li(Ni, Co, Al)O-2/Li(Ni, Mn, Co)O-2 was only 0.08 %. That is, the separating selectivity was 1250. Mechanism study revealed that the peeling-off was achieved through selective destruction of the LiFePO4 crystal and the matrix of polyvinylidene fluoride (PVDF) binder. Particularly, the crystal structure of LiFePO4 was firstly destructed by sulfide, thus LiFePO4 particles were detached from the matrix of PVDF binder. Then, the PVDF binder without LiFePO4 particles filling were more susceptible to be brittlely peeled off by the micro-explosion force of hydrogen from the reaction of Al foil with water due to the weakened mechanical strength. The process is suitable for recycling varied types of spent LIBs, having a strong potential for industrial application.