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Ultracapacitor Technology

Category: Site materials

Wednesday, 28 April 2010

Written by Andrii Buvailo

ULTRACAPACITOR TECHNOLOGY

Electrochemical Double Layer Capacitor (EDLC), also known as Ultracapacitor or Supercapacitor, is an energy storage device, functionally equivalent to any other known type of capacitors. Principal distinction, however, consists in a huge energy storage potential of Ultracapacitors, which is thousands of times greater than that of high-capacity electrolytic capacitors.

Ultracapacitor Principal

Conventional capacitors consist of two conductive (metal) plates separated by a dielectric layer. Electrostatic capacitance of the device is directly proportional to the area of the plates and permittivity of the dielectric layers, while being inversily proportional to the layer thickness. In other words, high values of the plates area and dielectric layer permittivity combined with low value dielectric layer thickness are needed to achieve large capacitance. In practice, however, the dielectric layer thickness can not be reduced infinitely, otherwise resulting in the capacitor breakdown. On the other hand, an increase in the plate area is also limited, otherwise leading to unacceptable increase in the overall dimensions.

The alternative way to achieve high capacitance on the order of 10 F/cm³ is to use nanosized materials for electrode manufacture. These materials possess huge specific surface area - up to 2000 m²/g. Such materials include, in particular, special nanoporous activated carbon powders. Activated carbon consists of extremely small and very "rough" particles, sized in a range of 3-7 micron, which in bulk, forms a low-density volume of particles with pores of different size that resembles a sponge.

Nanoporous activated carbon

Nanoporous material structure under electrone microscope.

The ultracapacitor consists of two electrodes immersed into a special organic electrolyte. Very thin double electric layer, on the order of 1 nm, forms on the developed surface of each electrode under the applied external voltage. Schematic representation of this process is shown in a picture below:

Yunasko ultracapacitor electrochemical scheme

During the capacitor charging process, the charge is accumulated in the negative and positive carbon electrodes and maintained there by the attraction of cations and anions (positively and negatively charged particles of electrolyte), respectively. The amount of charge that can be maintained in the capacitor is proportional to the accessible surface of the electrodes that can interact with ions of electrolyte. Hence, as we increase the effective surface of the electrode the overall capacitance increases. The use of activated carbons allows to achieve tremendous capacitance value.

Ultracapacitors are able to provide huge amount of energy in a very short period of time. It is so huge that we can even burn nails with it!

Ultracapacitor Design

On the whole, there are two maror types of ultracapacitor cells: cycindrical and prismatic. A typical ultracapacitor cell resembles a sandwich, or a roll, of thin aluminum foil and carbon electrodes. To prevent the short circuits between the electrodes, an ionically permeable dielectric separator is used. The thin foils, acting as current collectors, are later joined to the corresponding current leads (negative and positive), which are used for technical connections.

Yunasko ultracapacitor design

YUNASKO is developing prismatic ultracapacitor cells. Prismatic shape is beneficial due to maximazing efficiency of the packing cells into modules which is especially important for applications, where the space for the energy storage module is limited (in automobiles, consumer electronics etc).

Yunasko ultracapacitor cell overview

YUNASKO Profile

Category: Site materials

Saturday, 15 May 2010

Written by Andrii Buvailo

YUNASKO PROFILE

YUNASKO LTD was founded in early 2010 in a city of London, United Kingdom and currently holds its main subsidiary YUNASKO-UKRAINE LLC and a Pilot Plant facility, both situated in Ukraine. All entities are operating under collective brand "YUNASKO". Main operational activity and R&D work is conducted in Kiev, while a small series production is carried out in a city of Khmelnitskiy, Ukraine. Large scale ultracapacitor production plant is currently under development in Riga, Latvia. The plant is operated by YUNASKO-Latvia SIA.

YUNASKO is the developer and licensor of the leading technology for the energy storage devices. This technology is ready for the large scale manufacturing by world class electronics manufacturers. Company develops ultracapacitors (other name - supercapacitors), which present a type of energy storage devices characterized by prominent power characteristics - well above conventional batteries. In addition, ultracapacitors possess long life-cycle and safe operations. Ultracapacitors can be used in a broad variety of applications, ranging from automobiles, heavy industrial machinery and smart grids to consumer electronics.

Our company offers ultracapacitors developed using proprietary technology which have low internal resistance (ESR), excellent specific power and energy characteristics, low weight and functional prismatic design. The overall result is a significant cost advantage with respect to competitors. It creates the superior opportunity for the company to acquire substantial market share within the next 3 to 7 years.

The company invests a great deal of efforts in R&D work in order to maintain superior performance characteristics over competitors. According to the results of independent testing, YUNASKO ultracapacitors are currently considered to be world-best among commercially available competitors.

R&D Laboratories

The main mission of the R&D facility, situated in Kiev (Ukraine) is to keep pace with rapidly growing scientific progress in the filed of ultracapacitors and maintain current superiority over competitors. Besides, YUNASKO Labs pursue stratigic goal of testing new materials and approaches towards creating even better devices.

Second major assignment for the R&D facility is testing ultracapacitor cells and modules, assembled at the Pilot Plant.

Yunasko R&D Labs at Kiev Ukraine

Pilot Plant

The Pilot Plant, situated in a city of Khmelnitskiy (Ukraine) is equipped to produce small series of ultracapacitor cells and modules.

Yunasko Pilot Plant at Khmelnitskiy Ukraine

Development

Category: Site materials

Saturday, 15 May 2010

Written by Alexander Shnaydruk

TECHNOLOGY STRATEGY

There is an obvious increasing interest in ultracapacitor (UC) technology and application all over the world but the UC market growth, in particular, in the automotive sector is still rather modest. YUNASKO is developing technology to allow ultracapacitors to gain much more market share in 2-3 years.

In our opinion, the main reason for certain skepticism from automakers side is a pretty fast progress in Li-ion technology on the one hand, and rather slow progress in UC technology, on the other hand. As pure “physical” devices, which do not involve any chemical or electrochemical transformations, UC’s must demonstrate by far faster charge/discharge operations and longer cycle life than any “chemical” batteries. With such a background UC devices can provide the key to a number of efficient power solutions that are mostly related with covering peak power values and load leveling the batteries in various combined power sources.

UC devices must clearly demonstrate much higher power density (due to their much lower inner resistance) than Li-ion or any other batteries. This, accompanied by UC long life, wide operation temperature range, safety and cost reduction will help them to clear their way to the market.

As was mentioned above, another important issue is the cost of materials that are used in ultracapacitor technology. In particular, organic electrolytes and nanoporous carbon powders, which are typically used as electrode materials, contribute significantly to the total cost. The cost of electrolytes will be reduced due to scaling their production, while the cost of carbons depends strongly on precursor materials and treatment methods. In our technology we normally use low cost precursors and treatment to produce electrode materials with the pore size distribution needed. As a result low cost nanoporous carbon can be produced that meet the UC technology cost requirements.

We also pay significant attention to the manufacturability aspects of our newly developed technologies. It gives us the path towards the successful commercialization and correct planning for the large scale manufacture plant which will be able to supply the range of UC products starting from 2012-13.