The electrochemical tests were performed using coin-type cells which were assembled in an argon-filled glove box with both moisture and oxygen contents below 1 ppm [5] and [15]. The cathodes were fabricated by mixing the active materials (80 wt %), carbon black (15 wt %) and PVDF (poly(vinyldifluoride)), Aldrich, 5 wt %) in NMP (N-methyl-2-pyrrolidone) solvent. The resulting slurry was pasted onto aluminium foil and dried at 60 °C for 12 h. Then the foil was punched into small disks with a diameter of 14 mm. Lithium foil was used as anode and the electrolyte used was 1 M LiPF6 in a 50:50 (w/w) mixture of ethylene carbonate and diethyl carbonate. Each electrode has approximately 1–2 mg of active materials. Galvanostatic charging/discharging tests were conducted using a battery tester (NEWAER) with a voltage window of 2 V–4 V at different current densities. CV (Cyclic voltammetry) was performed with an electrochemical workstation (CHI 660C).