Rate capability tests showed that artificial graphite after spheroidization treatment exhibited a higher capacity in the higher C-rate region (2~10C) at a 0.1 C rate charge and variable C-rates discharge. Artificial graphite after spheroidization treatment exhibited a higher capacity in the higher C-rate region (0.5~9 C) at the same C-rate charge and discharge. These results show that artificial graphite after spheroidization treatment has a large amount of isotropic microstructures that lithium ions can intercalate into the graphene layers from all directions via edge-plane surfaces. Therefore, the artificial graphite is more suitable than natural graphite for the anode materials of high rate batteries.

Unburned carbon is an industrial waste product of oil-fired fly ash. Recycled ground unburned carbon with an average particle size of 5 μm after heat treatment at 2500°C displayed an first coulombic efficiency of approximately 89.8% at a charge and discharge rate of 0.1 C. The discharging capacity of this type of carbon was 293.7 mAhg-1, and its capacity retention was approximately 94.7% after 50 cycles. However, the first coulombic efficiency of ground unburned carbon receiving nitric acid treatment after heat treatment increased to 91.1%, its discharging capacity increased to 318.6 mAhg-1, and its capacity retention increased to 98.5% after 50 cycles. Rate capability tests show that the unburned carbon after heat treatment exhibited a higher capacity in the lower C-rate region (0.2~3 C) at a 0.2 C rate charge and variable C-rates discharge. However, unburned carbon with nitric acid treatment is a suitable material for the higher C-rate region (5~10 C). Unburned carbon after heat treatment exhibited a higher capacity in the lower C-rate region (0.2~0.5 C) at the same C-rate charge and discharge.

Diamond films were deposited on (111) silicon wafers by microwave plasma chemical vapor deposition (MPCVD). The deposition parameters included a system power of 1200 W, chamber pressure of 110 torr, H2 flowing rate of 300 sccm, and a CH4 flowing rate of 15 sccm. The diamond particles measured about 5-6 μm, and morphology analysis revealed a rectangular structure stacked regularly on diamond films after deposition. X-ray diffraction (XRD) analysis detected (220) square structures. Annealing at 600 °C improved the quality of diamond film, making the peak of the Raman spectra at 1350 cm-1 sharper and higher. The (220) and (311) orientation structures on the diamond films decreased after annealing broke the surface morphology. To conduct electric and optical experiments conveniently, the deposited samples were immersed in acid (HNA, HF：HNO3：CH3COOH = 3：25：10) to remove the silicon layers. The HNA acid did not corrode diamond films seriously, but slightly damaged the incomplete (220) and (311) structures.