An amount (5 wt %) of lithium tungstate (LiWO) as an additive significantly improves the cycle and rate performances of the LiNiCoMnO electrode at the cutoff voltage of 4.6 V. The 5 wt % LiWO-mixed LiNiCoMnO electrode delivers a reversible capacity of 199.2 mA h g and keeps 73.1% capacity for 200 cycles at 1 C. It retains 67.4% capacity after 200 cycles at 2 C and delivers a discharge capacity of 167.3 mA h g at 10 C, while those of the pristine electrode are only 44.7% and 87.5 mA h g, respectively. It is shown that the structure of the LiNiCoMnO cathode material is not affected by mixing LiWO. The introduced LiWO effectively restrains the LiPF and carbonate solvent decomposition by consuming PF at high cutoff voltage, forming a stable cathode/electrolyte interface film with low resistance.

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Non-thermal C/H/Ar plasmas are widely applied to carbonaceous material production and processing. In this work, plasma parameters and gaseous species of the atmospheric non-thermal C/H/Ar plasmas produced by an atmospheric-pressure DC arc discharge generator in CH4/Ar were investigated. The voltage-current characteristics were measured for different CH4/Ar ratios. Optical emission spectroscopy was employed to analyze the electron excitation temperature, gas temperature and electron density under various discharge conditions. The hydrocarbon molecules produced in the CH4/Ar plasmas were detected with photoionization mass spectrometry. The optical spectral results demonstrated that the electron excitation temperature was 0.4-1 eV, the gas temperature was 2800-4200 K and the electron density was in the range of (5-20)×10 15 cm −3. The mass spectrum indicated that a variety of unsaturated hydrocarbons (C2H4, C3H6, C6H6, etc.) and several highly unsaturated hydrocarbons (C4H2, C5H6, etc.) were produced in the non-thermal arc plasmas.