均苯四酸钴铁MOFs衍生材料的制备及其锂离子电池性能研究

Preparation of Anode Materials Derived CoFe-MOFs Supported by Pyromellitic Acid and Study on the Performance of Lithium Ions Batteries

利用均苯四酸、硝酸钴、氯化铁和活性炭,采用一步水热法制备双金属钴铁金属有机框架(CoFe-MOFs-C),通过在氩气条件下以5℃/min的升温速度升到500℃,保温2 h,自然降温后获得碳包覆金属氧化物(M-CoFe-C),并通过红外波谱分析、XRD、扫描电镜、XPS和拉曼光谱等分析手段进行表征。该复合材料是碳紧紧包覆在钴铁氧化物的外层,作为锂离子负极材料,碳层提高电子在电极表面上的传输速度,并在充放电过程中抑制活性材料的体积膨胀。原位构造的包覆碳层,使复合物具有良好的循环稳定性。研究表明,在200 mA/g的电流密度下,第100个循环时的可逆容量达到668.2 mA·h/g。

The organic bimetallic cobalt iron metal framework(CoFe-MOFs-C)was prepared by a one-step hydrothermal method using pyromellitic acid,cobalt nitrate,ferric chloride and activated carbon.The metal oxide coated carbon(M-CoFe-C)was obtained by raising the temperature to 500℃at a rate of 5℃/min under argon gas conditions,holding for 2 h,naturally cooling,and was characterized by infrared spectroscopy,XRD,scanning electron microscopy,XPS and Raman spectroscopy.The composite material was cobalt iron oxide tightly coated with a layer of carbon.As lithium ion anode material,the carbon layer improves the electron transport speed on the electrode surface,and inhibits the volume expansion of the active material during charging and discharging,so it has good cycle stability.The research showed that at the current density of 200 mA/g,the reversible capacity at the 100th cycle can reach 668.2 mA·h/g.