摘要
采用浓硫酸浸出废旧石墨(SG)中的金属和杂质,得到硫酸处理后的石墨(ALG),加入铁源制备Fe_(3)O_(4)@Fe/ALG高性能锂离子电池复合负极材料。扫描电子显微镜(SEM)和透射电子显微镜(TEM)观察到,Fe_(3)O_(4)@Fe/ALG复合材料中,纳米级Fe_(3)O_(4)和金属Fe颗粒均匀分散在石墨片中,纳米Fe颗粒提高了复合材料导电性且对石墨的活性有催化作用。X射线光电子能谱(XPS)检测到Fe_(3)O_(4)@Fe/ALG复合材料有羧基(C(O)O)基团存在,该基团可以阻止溶剂分子的共嵌入,以提高材料与电解液的润湿性,从而减少界面阻抗,首次嵌锂时转变为羧酸盐和-Oli基团,形成稳定的固体电解质膜。电化学性能测试结果表明,Fe_(3)O_(4)@Fe/ALG复合材料在0.1 C下循环100圈后,放电比容量为590 mAh/g;0.5 C下循环300圈,放电比容量为497.6 mAh/g,表现出较高的容量和较好的循环性能。该方法不仅为废旧锂离子电池中负极石墨的回收再利用提供了一个新的思路,而且回收再利用的工艺简单、制备的氧化铁基复合材料性能较好,有利于实现工业化生产和实际应用。
Waste graphite from spent lithium ion batteries(LIBs)was treated by concentrated sulfuric acid to leach metals and impurities,the obtain sulfuric acid-treated graphite(ALG)was recombinated with iron source to prepare high-performance Fe_(3)O_(4)@Fe/ALG composite materials as anode material for LIBs.Scanning electron microscope(SEM)and Transmission electron microscopy(TEM)images show that nanoscale Fe_(3)O_(4) and metallic Fe particles are uniformly dispersed in graphite nanosheets.Nano-Fe particles improve conductivity of the composite and make an catalytic effect on activity of the regenerated graphite.X-ray photoelectron spectroscopy(XPS)detects the presence of carboxyl(C(O)O)groups in the Fe_(3)O_(4)@Fe/ALG composites,which can help prevent the co-intercalation of solvent molecules and improve wettability of the material to electrolyte and then decrease interfacial impedance.The groups transforms into carboxylate and-Oli groups in the first lithium intercalation process and forms a stable solid electrolyte membrane.The electrochemical test results show that the specific discharge capacities of the Fe_(3)O_(4)@Fe/ALG composite remains 590 mAh/g after 100 cycles at 0.1 C and 497.6 mAh/g after 300 cycles at 0.5 C,suggesting superior capacity and cycling performance.This method offers a new strategy to recycle waste graphite anode in spent LIBs.In addition,the simple technology and good electrochemical performances of the Fe_(3)O_(4)-based composite are favorable to production in large scale as well as practical application.
作者
梁力勃
杨生龙
蒋英
赖飞燕
张晓辉
LIANG Libo;YANG Shenglong;JIANG Ying;LAI Feiyan;ZHANG Xiaohui(Guidong Electronic Technology Co.,Ltd.,Hezhou Guangxi 542899,China;College of Materials and Chemical Engineering,Hezhou University,Hezhou Guangxi 542899,China)
出处
《电源技术》
CAS
北大核心
2021年第8期972-975,共4页
Chinese Journal of Power Sources
基金
广西科学研究与技术开发计划(桂科AA17202004)
贺州市创新驱动发展专项(贺科创ZX1907001)
广西大学生创新创业训练计划资助项目(201911838065,202011838050)。
