Ultra capacitors & Super Capacitors store electricity by physically separating positive and negative charges?unlike batteries which do so chemically. The charge they hold is like the static electricity that can build up on a balloon, but is much greater thanks to the extremely high surface area of their interior materials.

Nano Ultracapacitor Diagram


? An advantage of the ultracapacitor is their super fast rate of charge and discharge... which is determined solely by their physical properties. A battery relies on a slower chemical reaction for energy.

? A disadvantage of an ultracapacitor is that currently they store a smaller amount of energy than a battery does.. which makes them larger.

Ultracapacitors are very good at efficiently capturing electricity from regenerative braking, and can deliver power for acceleration just as quickly. With no moving parts, they also have a very long lifespan.

An ultra capacitor, also known as a double-layer capacitor, polarizes an electrolytic solution to store energy electro statically. Though it is an electrochemical device, no chemical reactions are involved in its energy storage mechanism. This mechanism is highly reversible, and allows the ultra capacitor to be charged and discharged hundreds of thousands of times.

Once the ultra capacitor is charged and energy stored, a load (the electric vehicle's motor) can use this energy. The amount of energy stored is very large compared to a standard capacitor because of the enormous surface area created by the porous carbon electrodes and the small charge separation created by the dielectric separator.



Here is a very basic example of how an ultracapacitor works by using a circuit that uses a dc motor.



TECHNICAL DESCRIPTION:
An ultracapacitor can be viewed as two non reactive porous plates, or collectors, suspended within an electrolyte, with a voltage potential applied across the collectors. In an individual ultra-capacitor cell, the applied potential on the positive electrode attracts the negative ions in the electrolyte, while the potential on the negative electrode attracts the positive ions. A dielectric separator between the two electrodes prevents the charge from moving between the two electrodes.

UltraCaps are currently used for wind energy, solar energy, and hydro energy storage.


Ultracapacitor Module Diagram



Electrical energy storage devices, such as capacitors, store electrical charge on an electrode. Other devices, such as electrochemical cells or batteries, utilize the electrode to create, by chemical reaction, an electrical charge at the electrodes. In both of these, the ability to store or create electrical charge is a function of the surface area of the electrode. For example, in capacitors, greater electrode surface area increases the capacitance or energy storage capability of the device.

A third type of storage device, the ultracapacitor, relies on the microscopic charge separation at an electrochemical interface to store energy. Since the capacitance of these devices is proportional to the active electrode area, increasing the electrode surface area will increase the capacitance, hence increasing the amount of energy that can be stored. This achievement of high surface area utilizes materials such as activated carbon or sintered metal powders. However, in both situations, there is an intrinsic limit to the porosity of these materials, that is, there is an upper limit to the amount of surface area that can be attained simply by making smaller and smaller particles. An alternative method must be developed to increase the active electrode surface area without increasing the size of the device. A much more highly efficient electrode for electrical energy storage devices could be realized if the surface area could be significantly increased.



Quote
*Patent - Author - Year -Title -Country -Assignee -Number -URL
Davis, James L.; Williams, Melanie; Pennisi, Robert W.; 1998 Electrical energy storage device having a porous organic electrode United States Motorola,


Use this Links For More
http://en.wikipediawiki/Supercapacitor

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This article is presented by:
KAVITHA.C
Third year
Electronics

ULTRA BATTERY

INTRODUCTION
Ultra battery is a hybrid energy device.
In this lead acid battery and asymmetric capacitor embedded in the same cell.
For significant reduction of the amount of gases emitted from vehicles and generators we can make use of ultra battery.
PSOC is employed.


HISTORY
Possible ancient batteries.
1800-Voltaic pile
1836-Daniell cell
1844-Grove cell
1860s-Gravity cell
1866-Leclanche cell
1887-Zinc –carbon cell
1903-Nickel-iron battery
1955-Common alkaline battery
1970-Nickel hydrogen battery
1980s-Nickel metal-hydride battery
1990s-Lithium ion battery


CAPACITOR ELECTRODE
Hydrogen gas generation in charging operation
Cycle characteristics
Input output characteristics
Cycle life test based on the RHOLAB

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Traditional capacitors

Two electrodes, or plates separated by a dielectric
Capacitor’s energy stored in electric field

CONSTRUCTION

Double-layer technology

Electrodes: Activated carbon (carbon cloth, carbon black, particulate from SiC )

Electrolyte: KOH, organic solutions, sulfuric acid

Limitations of Activated Carbon

Non uniform porosity:
Multiple time constant
Much of the surface area is not utilized
Limited ion mobility

Limited conductivity due to amorphous nature of activated carbon

Bonding limitation due to
Electrode junction has high resistance

FEATURES

Energy storage device with excellent power capabilities ,high reliability
Long life -1 million charging cycles
High capacitance –about 3000F
No chemical reaction
Improved safety
Enhance efficiency
Optimize system size and cost

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SUBMITTED BY TRYSON J PURATHUR

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ABSTRACT:

Electronics power systems in automotive applications are undergoing a massive change.
Firstly, the transition from internal combustion engines to electric, fuel cell, and hybrid power is gathering momentum. At the same time, cars are becoming more sophisticated, evolving towards an intelligent electrically-powered platform with many more electronic subsystems and accessories—requiring a substantial increase in the need for electric power
There have been fundamental problems of energy storage and delivery among automotive applications that have yet to be successfully and cost effectively overcome. Many of these issues are due to the limitations of batteries—heavy, large, with a limited charging rate and potentially high maintenance.
Recently, newer designs have taken advantage of the benefits of another component: the ultracapacitor. Ultracapacitors, utilize high surface area electrode materials and thin electrolytic dielectrics to achieve capacitances several orders of magnitude larger than conventional capacitors. . Integrating ultracapacitors with other energy devices solves many challenges that are not solved efficiently using a single device. For example, combining high energy lead-acid batteries and ultracapacitors can create a system that has the excellent energy, self-discharge, availability, and low cost associated with lead-acid technology, and the high charge acceptance, high efficiency, cycle stability, and excellent low-temperature performance of the ultracapacitor. Ultracapacitors can also play a valuable role in distributed power systems, thus simplifying the wiring required and reducing cost.

System design engineers can take advantage of the power of ultracapacitors to conserve energy by allowing the engine to stop while the vehicle is stationary, and then to be restarted nearly instantly on “tip in” of the throttle. Ultracapacitors also allow regenerative braking energy to be captured, thereby significantly increasing efficiency and reducing pollution. The use of engine start/stop and regenerative braking has been estimated to produce between 7 and 15% increased fuel efficiency while reducing pollution by even more.
Ultracapacitors are based on an electric double layer technology. An ultracapacitor stores energy electro statically by polarizing an electrolytic solution. Though it is an electrochemical device there are no chemical reactions involved in its energy storage mechanism. This mechanism is highly reversible, allowing the ultracapacitor to be charged and discharged hundreds of thousands of times—in fact, Maxwell’s latest ultracapacitors are rated at one million charging cycles.
Ultracapacitors are compact in size and can store a much higher amount of energy than conventional capacitors while also being able to deliver at a much higher power than batteries

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ULTRACAPACITORS
(A NEW REVOLUTIONARY TECHNOLOGY)
Abstract:
The science and technology of ultracapacitors are reviewed for a number of electrode materials, including carbon, mixed metal oxides, and conducting Polymers .More work has been done using microporous carbons than with the other materials and most of the commercially available devices use carbon electrodes and an organic electrolytes.
This paper reveals the importance and the urgent need for the evolution of ultra capacitors which is expected to bring a revolutionary and remarkable change in the replacement of the traditional batteries. The need for ultracapacitors is lucidly mentioned in this paper. The fundamental phenomena of capacitor charging is mentioned which serves as a foundation in further advancements. The role of Nanotubes in the development of ultra capacitor is dealt. The advantage of Nanotubes over conventional capacitors is explained. The main problem faced is the capacitor current is capacitor current is a function of both voltage change and capacitance change as a function of voltage. So the specifications are to be considered in the ultracapacitor. Using all these method of ultracapping a car is briefly dealt
INTRODUCTION:
A smattering of mass-transit vehicles and industrial machines may seem like one wimpy revolution, but revolutionary they are unlike most of their electric relatives, these vehicles all share one key attribute: they don't run on batteries. Instead, they are powered by ultracapacitors, which are souped-up versions of that tried-and-true workhorse of electrical engineering, the capacitor.
A bank of ultracapacitors releases a burst of energy to help a crane heave its load aloft; they then capture energy released during the descent to recharge. Because no chemical reaction is involved, ultracapacitors also known as supercapacitors and double-layer capacitors are much more effective at rapid, regenerative energy storage than chemical batteries are. What's more, rechargeable batteries usually degrade within a few thousand charge-discharge cycles. In a given year, a light-rail vehicle might go through as many as 300 000 charging cycles, which is far more than a battery can handle. The synergy between batteries and capacitors has been growing, to the point where ultracapacitors may soon be almost as indispensable to portable electricity as batteries are now.
Ultracapacitors are already all over the place. Millions of them provide backup power for the memory used in microcomputers and cell phones. Perhaps most exciting is could do for electric cars. They're being explored as replacements for the batteries in hybrid cars. In ordinary cars, they could help level the load on the battery by powering acceleration and recovering energy during braking. Most deadly to the life of a battery are the moments when it is subjected to high-current pulses and charged or discharged too quickly. Conveniently, delivering or accepting power during short-duration events is the ultracapacitors strongest suit. And because capacitors function well in temperatures as low as –40 ºC, they can give electric cars a boost in cold weather, when batteries are at their worst.
Reason behind developing Ultracapacitors:
The most common electrical energy storage device is the battery. Batteries have been the technology of choice for most applications, because they can store large amounts of energy in a relatively small volume and weight and provide suitable levels of power for many applications. In recent times, the power requirements in a number of applications have increased markedly and have exceeded the capability of batteries of standard design. This has led to the design of special high power, pulse batteries. Ultracapacitors are being developed as an alternative to pulse batteries. To be an attractive alternative, ultracapacitors must have much higher power and much longer shelf and cycle life than batteries. Ultracapacitors have much lower energy density than batteries and their low energy density is in most cases the factor that determines the feasibility of their use in a particular high power application. For ultracapacitors, the trade-off between the energy density and the RC time constant of the device is an important design consideration.
How do Ultracapacitors store energy?
The most common electrical energy storage devices are capacitors and batteries. Capacitors store energy by charge separation. The simplest capacitors store the energy in a thin layer of dielectric material that is supported by metal plates that act as the terminals for the device. The energy stored in a capacitor is given by 1/2 CV 2. The maximum voltage of the capacitor is dependent on the breakdown characteristics of the dielectric material.
An ultracapacitor, sometimes referred to as an electrochemical capacitor, is an electrical energy storage device that is constructed much like a battery. It has two electrodes immersed in an electrolyte with a separator between the electrodes. The electrodes are fabricated from high surface area, porous material having pores of diameter in the nanometer. Charge is stored in the micropores at or near the interface between the solid electrode material and the electrolyte. However, calculation of the capacitance of the ultracapacitor is much more difficult as it depends on complex phenomena occurring in the micropores of the electrode. It is convenient to discuss the mechanisms for energy storage in ultracapacitors in terms of double-layer and pseudo capacitance separately