Compounding different materials with different properties to be one electrode is a good and common way in supercapacitors. IrO 2 was used as an active and conductive oxide, and ZnO was used as a semiconductive oxide to change the band gap of IrO 2 . Carbon nanotubes (CNT) and graphene (G) were used to improve the microstructure of the oxides. The electrodes of IrO 2 -ZnO-carbon nanotube (CNT)/Ti and IrO 2 -ZnO-graphene oxide (G)/Ti were prepared by a thermal decomposition method, and the different effects of CNT or G on the properties were studied in detail. The surface of IrO 2 -ZnO-CNT/Ti had a "hill-bag" structure, and the IrO 2 -ZnO-G/Ti had a graphene sheet-layered fold structure. Their specific surface area and pore volume were significantly greater than those of an electrode without a carbon material. The specific capacitances of IrO 2 -ZnO-G/Ti and IrO 2 -ZnO-CNT/Ti were 681 and 501 F g −1 , respectively, which were higher than that of IrO 2 -ZnO/Ti (399 F g −1 ). The capacitance retention rate of the IrO 2 -ZnO-G/Ti electrode coating was better than that of IrO 2 -ZnO/Ti within 15,000 cycles but less than that of IrO 2 -ZnO/Ti after 15,000 cycles. Moreover, only a retention rate of 80.24% after 20,000 cycles was kept, which was worse than that of IrO 2 -ZnO/Ti (90.65%). The reasons were worth further investigation. The addition of carbon materials reduced the cycle stability, but the binding effect of graphene and the coating was better than that of carbon nanotubes. Graphene improved the overall performance better than carbon nanotubes. A binder-free asymmetric supercapacitor working in H 2 SO 4 solution was assembled with RuO 2 -MoO 3 /Ti and IrO 2 -ZnO-G/Ti as cathodic and anodic electrodes, respectively. It exhibited energy densities of 29.6 and 25.3 W h kg −1 when the power densities were 700 and 3505 W kg −1 , respectively. The primary charge/discharge mechanism of the asymmetric supercapacitor in the H 2 SO 4 solution was presented.
Compounding different materials to be the electrode is a good way in the field of supercapacitors. IrO2 was used as an active and conductor oxide, and ZnO was used as a semiconductor oxide. Carbon nanotube (CNT) and Graphene (G) were used to prepare the electrodes of IrO2-ZnO-carbon nanotube (CNT)/Ti and IrO2-ZnO-graphene oxide (G)/Ti by thermal decomposition method and their different effect on the properties was studied in detail. The surface of IrO2-ZnO-CNT/Ti had a "hill-bag" structure, and the IrO2-ZnO-G/Ti had a graphene sheet layered fold structure, their specific surface area and pore volume were significantly greater than that of an electrode without carbon material. The specific capacitances of IrO2-ZnO-G/Ti and IrO2-ZnO-CNT/Ti were 681 F g-1 and 501F g-1, respectively, which were higher than IrO2-ZnO/Ti (399 F g-1). The capacitance retention rate of the IrO2-ZnO-G/Ti electrode coating was 80.24% after 20,000 cyclic tests, which was worse than that of IrO2-ZnO/Ti (90.65%). The addition of carbon materials reduced the cycle stability, but the binding effect of graphene and the coating was better than that of carbon nanotubes. Graphene improved the overall performance better than that of carbon nanotubes. A binder-free asymmetric supercapacitor working in H2SO4 solution was assembled with RuO2-MoO3/Ti and IrO2-ZnO-G/Ti as cathodic and anodic electrode respectively. It exhibited the energy densities of 29.6 W h kg-1 and 25.3 W h kg-1 when the power density was 700 W kg-1 and 3505 W kg-1 respectively. The preliminary charge/discharge mechanism of the asymmetric supercapacitor in the H2SO4 solution was presented.
<div>Three suspension structures including the parallel vertical suspension (PVS), the horizontal parallel suspension (HPS), and the negative stiffness element added into suspension (NSES) of the driver’s seat are proposed to improve the driver’s ride comfort of off-road vehicles. Based on the dynamic models of the PVS, HPS, and NSES established and simulated under the same random excitations of the cab floor, the effect of the design parameters of the proposed models is analyzed, and the design parameters are then optimized to evaluate their isolation performance. The indexes of the root-mean-square (r.m.s) accelerations of the vertical seat direction, pitching seat angle, and rolling seat angle are used as the objective functions. The study results indicate that the dynamic parameters of the PVS, HPS, and NSES greatly affect the driver’s ride comfort while their geometrical dimensions insignificantly affect the driver’s ride comfort. With the dynamic parameters of the PVS, HPS, and NSES optimized, the r.m.s seat acceleration in the vertical direction with the NSES is strongly reduced by 74.0% in comparison with the HPS; while the r.m.s accelerations of the pitching seat angle and rolling seat angle with the PVS are greatly decreased by 99.1% and 99.8% compared to the NSES. Therefore, the ride comfort of the driver’s seat is remarkably improved by using the NSES while the driver’s seat shaking is obviously ameliorated by using the PVS. To enhance the ride comfort and reduce the shaking of the driver’s seat, a combination of the PVS and NSES should be applied to the seat suspension of off-road vehicles.</div>
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