Using potassium ferricyanide as a dopant to prepare K and Fe co-doped Li4Ti5O12

For the first time, K and Fe co-doped Li4Ti5O12 (LTO) was prepared using potassium ferricyanide as the dopant by a sol-gel assisted solid state method. To simplify, the effect of Fe to Ti atomic ratio on the properties of the prepared materials was mainly investigated. The characteristics of the obtained samples were mainly analyzed by X-ray diffraction (XRD), scanning electron microscopy (SEM), cyclic voltammetry (CV), electrochemical impedance spectroscopy (EIS) and galvanostatic charge-discharge tests. The XRD patterns strongly demonstrated the formation of Li4Ti5O12 (LTO) though some impurities like TiO2 were formed in the final products, and the SEM images indicated that smaller and regular particles with an average size of about 350 nm could be prepared when the Fe to Ti atomic ratio was 0.5% (sample c). The results of electrochemical measurements revealed that sample c delivered a high specific capacity of 168 mA h g(-1) after 20 cycles at 0.2 C rate, which was significantly larger than that of the pristine LTO (83.5 mA h g(-1)) prepared by the same method. This work was believed to have developed a novel way to produce K and Fe co-doped LTO, which was very beneficial to the development of LTO.