Nanosheet-structured NH 4 V 3 O 8 material was successfully prepared through microwave radiation at low temperature (65°C) without any surfactant. The phase compositions, morphologies and electrochemical performances of the samples were characterized by X-ray diffraction, scanning electron microscope, cyclic voltammetry and galvanostatic charge-discharge test. NH 4 V 3 O 8 nanosheets with the thickness of about 50nm exhibit a high discharge capacity of 266mAhg −1 at 15mAg −1 and good rate capability with the discharge capacity of 221mAhg −1 at 120mAg −1 , 208mAhg −1 at 240mAg −1 , and 196mAhg −1 at 300mAg −1 , indicating a promising application as cathode materials for Li-ion battery.