Browse Topic: Ultracapacitors and supercapacitors
Researchers at North Carolina State University have now identified a “sweet spot” at which the length of a threadlike energy storage technology called a “yarn-shaped supercapacitor” (YSC) yields the highest and most efficient flow of energy per unit length.
A new bendable supercapacitor made from graphene has been developed that charges quickly and safely stores a record-high level of energy for use over a long period. The technology overcomes the issue faced by high-powered, fast-charging supercapacitors: they usually cannot hold a large amount of energy in a small space.
The portable and electric energy storage market has long been dominated by lithium-ion batteries and supercapacitors, surpassing other energy storage systems in their ability to provide higher energy and power. However, in critical applications such as electric vehicles, there is a growing demand for a device that can efficiently produce both high power and high energy over a significant number of cycles. Meeting these rigorous standards presents new challenges for existing technologies, prompting researchers to explore alternative technologies for energy storage devices.
Researchers at Drexel University are one step closer to making wearable textile technology a reality. Recently published in the Royal Society of Chemistry’s Journal of Material’s Chemistry A, materials scientists from Drexel’s College of Engineering, in partnership with a team at Accenture Labs, have reported a new design of a flexible wearable supercapacitor patch. It uses MXene, a material discovered at Drexel University in 2011, to create a textile-based supercapacitor that can charge in minutes and power an Arduino microcontroller temperature sensor and radio communication of data for almost two hours.
Researchers have developed a low-cost device that can selectively capture carbon dioxide gas while it charges. Then, when it discharges, the carbon dioxide (CO2) can be released in a controlled way and collected to be reused or disposed of responsibly.
As the electrification of automobiles continues to accelerate, the need for a safe, reliable, high-power energy-storage technology is greater than ever. Ultracapacitors already have an established place in Voltage Stabilization Systems (VSS) for internal-combustion engine (ICE) stop-start applications. By providing additional voltage support during a high-current cranking event, voltage levels are maintained to allow proper operation of accessories without interruption and enable proper operation as battery state-of-health declines.
Micro-supercapacitors could revolutionize the way we use batteries by increasing their lifespan and enabling extremely fast charging. Now, researchers at Chalmers University of Technology have developed a method that represents a breakthrough for how such supercapacitors can be produced.
A new bendable supercapacitor made from graphene has been developed that charges quickly and safely stores a record-high level of energy for use over a long period. The technology overcomes the issue faced by high-powered, fast-charging supercapacitors: they usually cannot hold a large amount of energy in a small space.
This research aims at developing the suboptimal energy management strategy by using artificial neural network (ANN) for a triple-electrical-energy electric vehicle (EV). The controller hardware designs will be implemented in the future. Firstly, we constructed a low-order dynamic equations that abstracted the characteristics of the vehicle, including energy sources (the fuel cell, lithium battery, and supercapacitor), driver’s model, traction motor, transmission, and longitudinal vehicle dynamics, etc.. The key parameters were mostly retrieved from the commercialization software-Advanced Vehicle Simulator (ADVISOR). Base on the vehicle structure of the Toyota Mirai, we built the range-extended EV. The powertrain system included an 110kW fuel cell set, a 40Ah lithium-ion battery set, and a 165F/48V supercapacitor and a 150kW AC motor. The ECMS control strategy included a six-layer for-loop: the battery state-of-health (SOH), power demand, the battery state-of-charge (SOC??), the supercapacitor state-of-charge (SOC????), the power ratio of battery to power demand(α) and the power ratio of the supercapacitor to power demand(β). The ECMS data for ANN training was divided to two parts, the input part is four for-loop and the output part is α and β. To evaluated the benefit of the ANN, a rule-based (RB) control was designed as well. A standard driving cycle, New European Drive Cycle (NEDC), was chosen for the energy improvement evaluation. The energy consumption for RB and ECMS is [17.6258, 8.9141kWh], respectively, in two-time NEDC cycles. The energy improvement for ECMS is approximately 50% and the ANN accuracy is higher than 90%. The hybrid system can be scaled down to a small mobility in the near future.
This document contains definitions currently used in the automotive industry as they relate to energy storage and batteries for starting, lighting, and ignition applications, as well as for hybrid electric vehicles (HEV) and electric vehicles (EVs). It is intended that this document be a resource for those writing other battery, HEV, and EV documents, specifications, standards, or recommended practices. The use of the term “battery” in this document can be assumed to be a rechargeable battery (secondary battery). The terminology may be applied to other industries if desired.
Supercapacitors are devices that store a dense electrical charge in an electrical field that provides electronics or a power grid with a quick jolt of power on demand. They have a capacitance value far higher than typical capacitors but at the cost of lower voltage limits. Unlike typical capacitors, supercapacitors don’t use conventional solid dielectric (insulator) — they utilize electrostatic double-layer capacitance (typically made of carbon) and electromechanical pseudo-capacitance (metal oxide or conducting polymer). Both contribute to the capacitor’s total capacitance and are designed for many rapid charge/discharge cycles over long-term energy storage. Hybrid supercapacitors boost that capacitance, energy density, and operating voltage (3.8 V maximum) up to 10X over symmetric supercapacitors.
Circuit designs exploiting the increased energy storage provided by supercapacitors require more careful consideration of the increased power handling than that of batteries when charging these devices. The unique composition of electrochemical double-layer capacitors (EDLC) inherently allows them to withstand large currents. Table 1 is a brief list of AVX cylindrical (SCC) and series-connected module (SCM) SuperCapacitors, displaying peak current supply and sink current capability. These maximum specifications will typically exceed current capability of charge sources and lead to failures within the power supply system.
With recent advances in electric vehicles, there is a plethora of powertrain topologies and components available in the market. Thus, the performance of electric vehicles is highly sensitive to the choice of various powertrain components. This paper presents a multi-objective optimization model that can optimally select component sizes for batteries, supercapacitors, and motors in regular passenger battery-electric vehicles (BEVs). The BEV topology presented here is a hybrid BEV which consists of both a battery pack and a supercapacitor bank. Focus is placed on optimal selection of the battery pack, motor, and supercapacitor combination, from a set of commercially available options, that minimizes the capital cost of the selected power components, the fuel cost over the vehicle lifespan, and the 0-60 mph acceleration time. Available batteries, supercapacitors, and motors are from a market survey. The considered lifespan is taken as 10 years, and the traveling distance is estimated at 50.9 miles per day using a combination of standard driving cycles. The resulting optimization problem is solved with the help of a quasi-static powertrain model which is developed using MATLAB/Simulink. A Genetic Algorithm is used to find the optimal solution in the case study. Normalized weighting factors are given to help users meeting their preferred performance during the power component design. Battery packs in the case study are chosen from LiFePO4 18650 cells with total capacity up to 100 kWh. Seven available types of supercapacitors along with 6 popular motors are also included in the design options. Two samples of the design results are compared to analyze the relevant tradeoff between performance indicators and cost.
Researchers have engineered a novel type of supercapacitor that remains fully functional even when stretched to eight times its original size. It does not exhibit any wear and tear from being stretched repeatedly and loses only a few percentage points of energy performance after 10,000 cycles of charging and discharging. The supercapacitor could be part of a power-independent, stretchable, flexible electronic system for applications such as wearable electronics or biomedical devices.
Researchers have created a flexible, lightweight, cost-effective plant-based energy storage device that in the near future could charge devices — even electric cars — within a few minutes.
A new supercapacitor based on manganese oxide could combine the storage capacity of batteries with the high power and fast charging of other supercapacitors. By combining manganese oxide with cobalt manganese oxide, a heterostructure is formed in which interfacial properties can be tuned.
Global warming has put the transport sector, a major contributor of CO2 emissions, under high pressure to improve efficiency. In this context, ultra-light vehicles weighting less than 500 kg, as well as hybrid powertrains, are nowadays seen as promising development trends. The design process of the powertrain of a vehicle combining the advantages of the two concepts is presented in this paper. Through a performance study based on a simple MATLAB model, and mathematical simulation, a proposal is made. A powertrain using a battery and supercapacitor 48V dual power source network, two electric motors and clutches to switch between conventional, parallel, series and full electric modes proves to be an interesting system in terms of performance and costs. A simulation study conducted on a scenario with different outcome possibilities showed that high modularity of the system allows to achieve fuel efficiencies equivalent to approximately 3 l/100 km on the Artemis cycle. Finally, integration, packaging and cost are considered and some hints for further powertrain efficiency improvements are presented.
Energy harvesting devices are in high demand to power the millions of devices that make up the Internet of Things. By providing continuous power to a rechargeable battery or supercapacitor, energy harvesters can reduce the labor cost of changing out batteries when they fail and keep dead batteries out of landfills.
The R&D dimension of the automotive industry often reveals novel solutions and cross-linking between materials, but a team of international scientists has come up with something truly unusual: boosting supercapacitor power and efficiency using newly developed “laxatives.” It's all about developing improved electrolytes as part of a program to enhance supercapacitor performance, making them more practical with enhanced energy storage for use in hybrid and electric vehicles (EVs). To do this, the team designed a new class of detergents involving the use of self-assembled nanostructures in detergent-like ionic liquids (IL), to facilitate improved charge storage at electrified interfaces. These detergents are chemically similar to human laxatives, said Dr. Gavin Hazell, a chemistry lecturer at the University of Chester's Faculty of Science and Engineering, and a member of the international team: “A discovery of this kind utilizes scientists from across the globe. We have a very diverse set of skills including synthetic chemistry, advanced structural, microscopy and computational methods.”
When driving in mountainous areas, vehicles often encounter downhill conditions. To ensure safe driving, it is necessary to control the speed of vehicles. For internal combustion engine vehicles, auxiliary brake such as engine brake can be used to alleviate the thermal load caused by the continuous braking of the friction brake. For battery electric vehicles (BEVs), regenerative braking can be used as auxiliary braking to improve brake safety. And through regenerative braking, energy can be partly converted into electrical energy and stored in accumulators (such as power batteries and supercapacitors), thus extending the mileage. However, the driver's line of sight in the mountains is limited, resulting in a certain degree of blindness in driving, so it is impossible to fully guarantee the safety and energy saving of downhill driving. Therefore, taking a pure electric light truck as an example, the system proposed in this paper first analyzes the driver's driving intention, proposes the system startup and exit strategy, and then combines the geographic information system (GIS) mountain road information, downslope speed limit and vehicle parameters, considering the motor and battery characteristics, establishes mathematical models such as the regenerative braking model and the brake temperature rise model based on vehicle dynamics and the conservation of energy, determines the appropriate braking mode(There are two braking modes)and the slope top safe speed by calculation, and reminds the driver when going uphill and downhill. The main goal is to use more regenerative braking, reduce the use or duration of the main brake, avoid overheating the main brake, improve the safety during continuous braking, and achieve smarter energy management. Finally, simulations are carried out under different conditions of vehicle speed, slope length, slope gradient and battery SOC. The results show that the system has a good energy-saving effect and can significantly improve the safety of BEVs running downhill.
Growing demand for electric vehicles and more sustainable forms of transport means finding new forms of energy storage such as batteries, supercapacitors, and fuel cells. Currently, a major challenge facing the industry is the poor performance quality of rechargeable batteries, which often lose energy and power too quickly over time.
Researchers from UCLA and the University of Connecticut have designed a new biofriendly energy storage system called a biological supercapacitor, which operates using charged particles, or ions, from fluids in the human body. The device is harmless to the body’s biological systems, and it could lead to longer-lasting cardiac pacemakers and other implantable medical devices.
I'm writing this editorial from a hotel overlooking the brilliantly lit and bustling Las Vegas strip. This description also is apropos for the Las Vegas Convention Center this particular week in March, where bright lights shine on hulking metal machines and nearly 128,000 attendees bustle about the 2.8 million-plus ft2 of exhibit space to check out the latest and greatest the equipment makers and their suppliers have to offer. ConExpo/Con-Agg and the collocated IFPE (International Fluid Power Exposition) did not disappoint. Walking the expansive halls and sizable outdoor lots, and chatting with many exhibitors over the course of the week, I sensed a mostly positive outlook for the business being conducted on site, as well as a general good feeling for the economy and industry moving forward.
Both the aerospace and automotive industries depend increasingly on electrochemical energy storage. Reduction in mass, increase in energy, and increase in power can benefit both of these areas dramatically. Supercapacitors are currently under consideration for use in both hybrid electric vehicles (HEV) and electric vehicles (EV) to improve delivery of power (due to their high rate capability), improve the life of the lithium-ion batteries (due to their ability to buffer the detrimental effects of high current pulses or alternating currents on the battery), and implement more efficient capture of regenerative breaking energy (due to their excellent charge acceptance at high rates).
Environmental concerns and limited fossil fuels reserves have fostered an increased interest in alternative propulsion systems. In this scenario, electric traction, with its inherent zero local emissions, high efficiency and improved operational performance (acceleration and hill climbing potential), emerges as a desired option for public transport systems. Transit buses, the prevailing transport system in cities, and, hence, strong contributors to traffic environmental impact on urban areas, can reduce considerably their environment burden with the use of electric traction. This means less local pollutants, specially particulate matter - PM and nitrogen oxides - NOx, currently the “Achilles heel” of diesel engines, as well as CO2 greenhouse emissions - GHG. The so called autonomous electric bus - e-bus, i.e. that one independent of electric grid, fed while running solely by an energy storage device - ESD (batteries, ultracapacitor, flywheel) and charged at bus stops into the so called “opportunity charge” concept emerges as the best option for short range/medium demand corridors in downtown areas, as enables a low vehicle space and weight impairment for ESD assembly, in benefit of passenger capacity and operational performance. The so called ultracapacitors or supercapacitors are energy storage devices based mainly on the highly reversible electrostatic double layer capacitance, formed at the interface between an electrode and an electrolyte solution. Their charge and discharge process, in contrast to battery technologies (based on chemical reactions), occurs upon the movement of ions. With no chemical bonds being made or broken, very fast charge and discharge processes are possible, even at low temperatures, with lifecycle of over 1 million cycles with minimal degradation, albeit at a lower energy density than batteries. These features favor ultracapacitor use in high power burst charge (charge at bus stops and regenerative brake) and discharge (acceleration and uphill climbing) regimes, typical of “stop and go” urban cycles. In this context, ultracapacitor buses appears as a promising technology to be used in short range central bus routes, in which e-bus runs solely with ultracapacitor ESS (without batteries) and can travel along its route with few seconds’ ultrafast charging (up to 500 kw) events at predetermined bus stops or a single, few minutes’ charge each time upon returning to its terminal (depending on the duty cycle and air conditioning use). This work is supposed to present an overview of ultracapacitor basics technology and an evaluation of the applicability of this groundbreaking cutting edge technology into central short range transit bus market, followed by a technical evaluation of some prototypes ultracapacitor bus experiences currently in test in Europe and China.
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