Supercapacitor Units Research Articles

KCu7S4 nanowires and the Mn/KCu7S4 nanostructure for solid-state supercapacitors

We report a novel pseudocapacitor based on KCu7S4 nanowires. To improve the electrochemical performance of the KCu7S4 capacitor, we changed the structure of the KCu7S4 nanowire electrode by coating Mn particles (Mn/KCu7S4). The preferable capacitance is shown by the Mn/KCu7S4 hybrid capacitor, which displays large specific capacitance (1620 F g−1) at a scan rate of 1 mV s−1, high energy density, good cyclic stability and three supercapacitor units in series light 400 light-emitting diodes (LEDs) for 2 min. The much-increased capacity, rate capability, and cycling stability may be attributed to the Mn/KCu7S4 hybrid structure, which enhances ionic and electronic transport through the electrode system.

A Rack-and-Pinion Pumping Unit Design

This paper presents a rack-and-pinion pumping unit. A type of SRD (switched reluctance driver) motor is utilized as the driving unit of the pumping unit. The rotation direction of the output shaft of the motor can change automatically, without reversing mechanism，so it can directly dive the gear box and then drive the rack-and-pinion in which the rack connected with the suck rod. Additionally, a super capacitor unit and control unit of charge and discharge is used to design the balance of the pumping unit. Due to the special balance design and no crank-rocker mechanism in the rack-and-pinion pumping unit, it has features of simple structure, less floor area, well balanced and high running efficiency. The most important is that the stroke and number of punching can be adjusted in a wide range which can adapt to different oil wells.

A Study on the Characteristics of Supercapacitor for High Voltage System

Supercapacitors as novel energy storage devices between conventional capacitors and batteries, with more specific capacitance and energy densities than conventional capacitors and more power densities than batteries are to be used in many fields. And, social demand on fuel economy and reducing pollution needs equipment of new function such as energy storage system with good power performance, high cyclability and good energy efficiency. Supercapacitor is regarded as one of good alternatives for meeting the requirement of market with excellent power performance and high cyclability. This paper deals with the fundamental characteristics of supercapacitor unit and charge and discharge behavior of supercapacitor module for developing 42V hybrid energy storage system with lead acid battery and supercapacitor in order to adopt to 42V power net for vehicle.

Electrochemical characterization of MnO 2 as the cathode material for a high voltage hybrid capacitor

Manganese dioxide (MnO 2) was prepared using the ultrasonic method. Its electrochemical performance was evaluated as the cathode material for a high voltage hybrid capacitor. And the specific capacitance of the MnO 2 electrode reached 240 F.g −1. The new hybrid capacitor was constructed, combining Al/Al 2O 3 as the anode and MnO 2 as the cathode with electrolyte for the aluminum electrolytic capacitor to solve the problem of low working voltage of a supercapacitor unit. The results showed that the hybrid capacitor had a high energy density and the ability of quick charging and discharging according to the electrochemical performance test. The capacitance was 84.4 μF, and the volume and mass energy densities were greatly improved compared to those of the traditional aluminum electrolytic capacitor of 47 μF. The analysis of electrochemical impedance spectroscopy (EIS) showed that the hybrid capacitor had good impedance characteristics.

Optimization of Fuel Cell and Supercapacitor for Fuel-Cell Electric Vehicles

In this paper, an optimal design to minimize the cost of the fuel cell and supercapacitor in a fuel-cell electric vehicle is presented. It is assumed that the cost of the fuel cell and supercapacitor is a function of the number of units of each, respectively. The constraints on the number of fuel-cell units and supercapacitor units are derived according to the system requirement of maintaining stable dc-link voltage for all possible vehicle operations. These constraints are combined with the derived cost function to obtain the optimal number of fuel-cell units and supercapacitor units and the minimum cost. The cost, volume, and weight of the optimized fuel cell and supercapacitor of the powertrain and the fuel economy of the vehicle are evaluated. Simulation results are presented to verify the design

Development of the 40 V hybrid super-capacitor unit

A newly hybrid super-capacitor for the power source of electromagnetic (EM) launch system is developed. By the optimization of combined structure, the hybrid super-capacitor unit can be charged and discharged at the working voltage of 40 V. Compared with other super-capacitors, the working voltage gets raising actually. According to the electricity performance test, it shows that the capacitor has the high energy density and the ability of quick charging and discharging. And the analysis of electrical impedance spectroscopy (EIS) shows that it has good characteristics of impedance and frequency. The analysis method of equivalent circuit for the capacitor with impedance characteristic is meaningful for the comprehension of the process and determination of the production processes.