In this book, synthesis, structural and electrochemical performances, especially kinetics of LiFeSO4F are investigated. LiFeSO4F powder was obtained through ionothermal and solid state methods. The proporties of obtained powders were characterized by X-ray diffraction (XRD) and scanning electron microscope (SEM). The diffusion path of LiFeSO4F was investigated through crystallography point of view. The concept of Li+ hopping distance and anion window were used to determine the fastest diffusion path. First principle calculation data on activation energy was applied to derive the theoretical diffusion coefficient in the order of 10^-15 cm2/s. The apparent chemical diffusion coefficients (D) of lithium in the material were measured by cyclic voltammetry (CV), galvanostatic intermittent titration technique (GITT), electrochemical impedance spectroscopy (EIS) and potential relaxation technique (PRT) methods. Rate and cycling performance were studied with film and/or powder electrode. The effect of particle size to the electrochemical performance was studied. The reason of moisture sensitivity is proposed and tested.