Large Expansion of Operating Voltage Window in Polymer Based Flexible Solid State Supercapacitor

MRS Advances ◽  
2018 ◽  
Vol 3 (23) ◽  
pp. 1291-1300
Author(s):  
Curtis White ◽  
Tristan Skinner ◽  
Kevin Santiago ◽  
Sangram K. Pradhan ◽  
Messaoud Bahoura

ABSTRACTSpecific demand of lightweight and high efficient flexible energy unit is increased day by day for its integration into bendable electronics devices. Super-capacitor is one of the promising power unit to meet the current requirement. Flexible metal oxide and polypyrrole based flexible electrode materials are prepared using electrodeposition. The calculated specific capacitances of the devices shows 0.5 mill farad per gram. The super-capacitor is ultra-flexible, stable with operational voltage window expands from 0.8 to 2.5 V which can help to reduce the number of super-capacitor in series connection to obtain the same output. In this study, a conductive polymer can be coupled with MnO2 to improve capacitance and conductivity of a hybrid structure based on MnO2.

2013 ◽  
Vol 288 ◽  
pp. 148-155
Author(s):  
Qi Hui Lv ◽  
Xin Yuan Xiao

In order to reduce loader engine installed power and save energy, we designed the driving scheme of power system for parallel hybrid loader by Analysis of different way of connection between diesel engine and electric motor. We chose ISG power electric multifunction and super capacitor as the core component to design the Loader auxiliary power system and movable arm cylinder gravitational potential energy recovery system. We established ADVISOR software model of hybrid power Loader, and the simulation results show that diesel engine installed power of the hybrid power Loader is reduced by 21%; fuel consumption is reduced by 9.2%. Through optimize control strategy, the diesel engine can always working in high efficient area or idle area. Practical application shows that this design scheme has the potential economic and environmental benefits.


Electronics ◽  
2018 ◽  
Vol 7 (8) ◽  
pp. 126 ◽  
Author(s):  
Lina Wang ◽  
Junyi Yang ◽  
Haobo Ma ◽  
Zeyuan Wang ◽  
Kabir Olanrewaju ◽  
...  

Silicon Carbide (SiC)-based Bi-Directional Switches (BDS) have great potential in the construction of several power electronic circuits including multi-level converters, solid-state breakers, matrix converters, HERIC (high efficient and reliable inverter concept) photovoltaic grid-connected inverters and so on. In this paper, two issues with the application of SiC-based BDSs, namely, unwanted turn-on and parasitic oscillation, are deeply investigated. To eliminate unwanted turn-on, it is proposed to add a capacitor (CX) paralleled at the signal input port of the driver IC (integrated circuit) and the capacitance range of CX is also analytically derived to guide the selection of CX. To mitigate parasitic oscillation, a combinational method, which combines a snubber capacitor (CJ) paralleled with the JFET (Junction Field Effect Transistor) and a ferrite ring connected in series with the power line, is proposed. It is verified that the use of CJ mainly improves the turn-off transient and the use of a ferrite ring damps the current oscillation during the turn-on transient significantly. The effects of the proposed methods have been demonstrated by theoretical analysis and verified by experimental results.


2018 ◽  
Vol 386 ◽  
pp. 359-364
Author(s):  
Yury M. Nikolenko ◽  
Denis P. Opra ◽  
Alexander K. Tsvetnikov ◽  
Alexander Yu. Ustinov ◽  
Valery G. Kuryavyi ◽  
...  

The hydrolytic lignin derivatives have been prepared via its physical activation (high-temperature heating in vacuum) followed by chemical modification (fluorination). The obtained products were characterized using scanning electron microscopy, X-ray diffraction, transmission electron microscopy, Raman spectroscopy, and X-ray photoelectron spectroscopy. It was found that the graphitized product of thermal activation up to 1000 °C at a low rate of < 2 °C/min under high vacuum shows an enhanced specific surface area (215 m2/g), that makes its potentially useful as sorbent, catalytic substrate or electrode material. To clarify the potentialities of hydrolytic lignin derivatives for energy storage and conversion, the electrochemical system with metallic lithium anode was applied. The galvanostatic discharge of battery at a current density of 100 μA/cm2between 3.0 and 0.5 V shows that the specific capacity of thermally activated derivative is equal to 845 mA·h/g, while the untreated lignin yields only 190 mA·h/g. The improve of the electrochemical performance of product originates from its graphitization, increasing electronic conductivity, and, possibly, enhanced ability to adsorb of oxygen. The fluorination of both the lignin and its thermally activated form results in higher operating voltage of battery, as seems, due to the involvement of fluorine bound to carbon in electrochemical process.


NANO ◽  
2020 ◽  
pp. 2150005
Author(s):  
Meng Sun ◽  
Zhipeng Cui ◽  
Huanqing Liu ◽  
Sijie Li ◽  
Qingye Zhang ◽  
...  

FeOOH nanorods (NRs) wrapped by reduced graphene oxide (rGO) were fabricated using a facile solvothermal method. When used as anode materials for lithium-ion batteries (LIBs), the FeOOH NRs/rGO composites show a higher capacity (490[Formula: see text]mAh g[Formula: see text] after 100 cycles at a current density of 100[Formula: see text]mA g[Formula: see text] and better rate capability than pure FeOOH NRs. The enhanced electrochemical performance can be ascribed to the hybrid structure of FeOOH and rGO. On one hand, the introduction of rGO can improve electronic conductivity and reduce charge-transfer resistance for electrode materials. On the other hand, the distinctive structure (FeOOH NRs surrounded by flexible rGO) can effectively buffer large volume change during the Li[Formula: see text] insertion/extraction process. Our work provides a feasible strategy to obtain high-performance LIBs.


Nanomaterials ◽  
2020 ◽  
Vol 10 (2) ◽  
pp. 289 ◽  
Author(s):  
Kugalur Shanmugam Ranjith ◽  
Ganji Seeta Rama Raju ◽  
Nilesh R. Chodankar ◽  
Seyed Majid Ghoreishian ◽  
Cheol Hwan Kwak ◽  
...  

A flexible asymmetric supercapacitor (ASC) with high electrochemical performance was constructed using reduced graphene oxide (rGO)-wrapped redox-active metal oxide-based negative and positive electrodes. Thin layered rGO functionality on the positive and the negative electrode surfaces has promoted the feasible surface-active sites and enhances the electrochemical response with a wide operating voltage window. Herein we report the controlled growth of rGO-wrapped tubular FeMoO4 nanofibers (NFs) via electrospinning followed by surface functionalization as a negative electrode. The tubular structure offers the ultrathin-layer decoration of rGO inside and outside of the tubular walls with uniform wrapping. The rGO-wrapped tubular FeMoO4 NF electrode exhibited a high specific capacitance of 135.2 F g−1 in Na2SO4 neutral electrolyte with an excellent rate capability and cycling stability (96.45% in 5000 cycles) at high current density. Meanwhile, the hydrothermally synthesized binder-free rGO/MnO2 nanorods on carbon cloth (rGO-MnO2@CC) were selected as cathode materials due to their high capacitance and high conductivity. Moreover, the ASC device was fabricated using rGO-wrapped FeMoO4 on carbon cloth (rGO-FeMoO4@CC) as the negative electrode and rGO-MnO2@CC as the positive electrode (rGO-FeMoO4@CC/rGO-MnO2@CC). The rationally designed ASC device delivered an excellent energy density of 38.8 W h kg−1 with a wide operating voltage window of 0.0–1.8 V. The hybrid ASC showed excellent cycling stability of 93.37% capacitance retention for 5000 cycles. Thus, the developed rGO-wrapped FeMoO4 nanotubes and MnO2 nanorods are promising hybrid electrode materials for the development of wide-potential ASCs with high energy and power density.


2011 ◽  
Vol 1313 ◽  
Author(s):  
Indranil Lahiri ◽  
Sung-Woo Oh ◽  
Yang-Kook Sun ◽  
Wonbong Choi

ABSTRACTRechargeable batteries are in high demand for future hybrid vehicles and electronic devices markets. Among various kinds of rechargeable batteries, Li-ion batteries are most popular for their obvious advantages of high energy and power density, ability to offer higher operating voltage, absence of memory effect, operation over a wider temperature range and showing a low self-discharge rate. Researchers have shown great deal of interest in developing new, improved electrode materials for Li-ion batteries leading to higher specific capacity, longer cycle life and extra safety. In the present study, we have shown that an anode prepared from interface-controlled multiwall carbon nanotubes (MWCNT), directly grown on copper current collectors, may be the best suitable anode for a Li-ion battery. The newly developed anode structure has shown very high specific capacity (almost 2.5 times as that of graphite), excellent rate capability, nil capacity degradation in long-cycle operation and introduced a higher level of safety by avoiding organic binders. Enhanced properties of the anode were well supported by the structural characterization and can be related to very high Li-ion intercalation on the walls of CNTs, as observed in HRTEM. This newly developed CNT-based anode structure is expected to offer appreciable advancement in performance of future Li-ion batteries.


2015 ◽  
Vol 1092-1093 ◽  
pp. 17-21
Author(s):  
Yi Dan Li ◽  
Du Ting Wang ◽  
Hong Ming Kang ◽  
Hong Fang Ru

The cascaded multilevel inverter may be the best topology to satisfy continuously increasing capacity and scale of grid-connected photovoltaic generation system due to its modularized circuit layout and sufficiently high operating voltage without devices in series. The operating principle of the cascaded multilevel inverter is presented. The control strategy of carrier phase shift PWM is proposed and discussed in detail. A grid-connected photovoltaic (PV) generation system based on a seven level cascaded inverter is provided. Simulation model of a seven level cascaded inverter with phase shifted PWM is built in Simulink environment and simulation results verify that the cascaded multilevel inverter can output high level voltage without devices in series, reduce harmonics, and output high quality waveforms.


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