Layered LiNi1/3Co1/3Mn1/3O2 was modified by poly(3,4-dioxyethylenethiophene) PEDOT via a facile method and characterized by X-ray diffraction (XRD), scanning electron microscopy (SEM), transmission electron microscopy (TEM) and infrared spectroscopy (IR). PEDOT modified samples exhibited both improved rate and cycle performance compared with the pristine LiNi1/3Co1/3Mn1/3O2. At a charge/discharge current of 1500 mA g−1, the discharge capacity was improved from 44.3 to 73.9 mAh g−1. The sample with 2 wt% and heat treated at 300 °C showed the optimized electrochemical performance. Galvanostatic intermittent titration technique (GITT) and cyclic voltammetry (CV) results indicated that the battery polarization of coated samples have been suppressed obviously because the PEDOT layer facilitated the electron transfer at the interface of electrode and electrolyte.