The electrodes electrolyte interfaces of lithium ion battery at high cell voltages were investigated by using in-situ electrochemical impedance spectroscopy (EIS) with three electrodes cell. NCM/C system electrodes were investigated separately in the electrolyte of LiPF₆ in ethylene carbonate (EC) and dimethyl carbonate (DMC) with and without the most commonly used additives vinylene carbonate (VC), vinyl ethylene carbonate (VEC) and fluoroethylene carbonate (FEC). Fourier transform infrared (FTIR) and ultraviolet-visible (UV-vis) were carried out to examine the stability of additives at the electrodes electrolyte interfaces at high cell voltage. This work provides valuable information for lithium ion battery at high cell voltage especially in the choice of electrolyte additives.