废旧LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)材料球磨-喷雾法再生研究

Study on Regeneration of Waste LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2) Materials by Ball Milling-Spray Method

为了改善再生锂离子电池材料的电化学性能,提出了一种球磨-喷雾法对废旧LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523)进行回收再生。该方法是通过对预处理后的废旧正极材料进行球磨细化,经过喷雾干燥迅速制备再生材料的前驱体,并结合高温煅烧制备再生NCM523材料。采用SEM、EDS、XRD、HRTEM、FT-IR、XPS、TG-DSC等对再生过程中材料的形貌、成分、物相及化学变化等进行了分析,且对再生NCM523组装的电池进行了电化学性能分析。结果表明,再生材料具有多孔结构,锂镍混排程度降低,电化学性能得到改善。在实验条件下得到的再生NCM523材料在0.11 C下的首圈放电比容量为159.053 mA·h/g,循环100圈后放电比容量为145.615 mA·h/g,容量保持率为91.55%,具有良好的容量保持率;电流密度为5 C的首圈放电比容量为126.974 mA·h/g。相较于传统的直接再生方法,球磨-喷雾再生法制备的NCM523的电化学性能得到明显改善。

In order to improve the electrochemical performance of regenerated lithium-ion battery materials,a ball milling-spray method was proposed to recover and regenarate waste LiNi_(0.5)Co_(0.2)Mn_(0.3)O_(2)(NCM523).This method includes ball milling and refinement for the pretreated waste cathode material,rapid preparation of the precursor of the regenerated material through spray drying,and high temperature calcination to preduce the regenerated NCM523 material.The morphology,component,phase and chemical change of the materials during the regeneration process were analyzed by SEM,EDS,XRD,HRTEM,FT-IR,XPS and TG-DSC,and the electrochemical properties of the batteries assembled with regenerated NCM523 were also analyzed.The results show that the regenerated material has a porous structure,and the degree of lithium-nickel mixing is reduced,resulting in improved electrochemical performance.The first cycle discharge specific capacity of the regenerated NCM523 obtained under experimental conditions is 159.053 mA·h/g at 0.11 C,and the discharge specific capacity is 145.615 mA·h/g after 100 cycles,with a good capacity retention rate of 91.55%.And its first cycle discharge specific capacity is 126.974 mA·h/g at a current density of 5 C.Compared with the traditional direct regeneration method,the electrochemical properties of NCM523 prepared by ball milling-spray regeneration method are significantly improved.