Improvement of Hybrid Electrode Material Synthesis for Energy Accumulators Based on Carbon Nanotubes and Porous Structures

Abstract

Carbon materials are promising for use as electrodes for supercapacitors and lithium–ion batteries due to a number of properties, such as non-toxicity, high specific surface area, good electronic conductivity, chemical inertness, and a wide operating temperature range. Carbon-based electrodes, with their characteristic high specific power and good cyclic stability, can be used for a new generation of consumer electronics, biomedical devices and hybrid electric vehicles. However, most carbon materials, due to their low electrical conductivity and insufficient diffusion of electrolyte ions in complex micropores, have energy density limitations in these devices due to insufficient number of pores for electrolyte diffusion. This work focuses on the optimization of a hybrid material based on porous carbon and carbon nanotubes by mechanical mixing. The purpose of this work is to gain new knowledge about the effect of hybrid material composition on its specific capacitance. The material for the study is taken on the basis of porous carbon and carbon nanotubes. Electrodes made of this hybrid material were taken as an object of research. Porous carbon or nitrogen-containing porous carbon (combined with single-, double-, or multi-layer carbon nanotubes (single-layer carbon nanotubes, bilayer carbon nanotubes or multilayer carbon nanotubes) were used to create the hybrid material. The effect of catalytic chemical vapor deposition synthesis parameters, such as flow rate and methane-to-hydrogen ratio, as well as the type of catalytic system on the multilayer carbon nanotubes structure was investigated. Two types of catalysts based on Mo12O28 (μ2-OH)12{Co(H2O)3}4 were prepared for the synthesis of multilayer carbon nanotubes by precipitation and combustion. The resulting carbon materials were tested as electrodes for supercapacitors and lithium ion intercalation. Electrodes based on nitrogen-containing porous carbon/carbon nanotubes 95:5% were found to be the most efficient compared to nitrogen-doped porous carbon by 10%. Carbon nanotubes, bilayer carbon nanotubes and multilayer carbon nanotubes synthesized using the catalyst obtained by deposition were selected as additives for the hybrid material. The hybrid materials were obtained by mechanical mixing and dispersion in an aqueous solution followed by lyophilization to remove water. When optimizing the ratio of the hybrid material components, the most effective porous carbon:carbon nanotubes component ratio was determined.

Determination of the Performance Characteristics of a Traction Battery in an Electric Vehicle

“…Using the experimental data on driving in other conditions does not allow us to estimate real drag forces acting on the wheels of an electric vehicle, because a drag moment reduced to a motor shaft will be greater when climbing and less when descending due to the presence of a drag moment when the vehicle is travelling along an uneven road [63,64].…”

Mathematical Modelling of Traction Equipment Parameters of Electric Cargo Trucks

“…In the linear section of the motor magnetisation curve, the main inductance is a constant value. At saturation of the motor magnetic core, the value of the main inductance decreases [67].…”

“…An alignment of th obtained values of battery energy without regeneration in real tests and the simulation in the driving cycle is shown in Figure 32. The graph shows the discrepancy between the real tests and the modelling of the system in the middle of the cycle; this is due to taking into account the needs of the electric vehicle, as well as the operation of the compressor of the pneumatic system [67].…”

Experimental Investigation on the Performance of the Scroll Expander under Various Driving Cycles

“…Energy storage technologies offer crucial solutions to overcome the fluctuations and intermittency of renewable energy [5,6]. A variety of types of energy storage technologies, such as electrochemical energy storage [7], pumped-hydro energy storage (PHES), thermochemical energy storage, magnetic energy storage, hydrogen energy storage [8], and CAES, are available [9]. Among them, PHES and CAES show the most potential for massive application [10].…”