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What is a supercapacitor? |
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A supercapacitor (also sometimes known as an ultracapacitor) is an electrochemical double layer capacitor (EDLC) that is a form of hybrid between a conventional capacitor and a battery, and accordingly can be used either to replace the battery in a design, or to extend its life span and power capability.
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How do supercapacitors differ from conventional capacitors? |
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Supercapacitors are a form of film capacitor, and film capacitors store their electric charge by means of two layers of conductive film separated by a dielectric material.
The charge accumulates on both conductive film layers, yet remains separated due to the dielectric.
This contrasts with electrolytic capacitors, which are composed of metal to which a thin layer of non-conductive metal oxide is added to serve as the dielectric.
These capacitors have an inherently larger capacitance than standard film capacitors, with relatively high power capability and relatively low energy density.
In an EDLC, the double layer creates a physical interface between a conductive solid and a liquid solution. The capacitance creates charge separation in the interface.
Electronic charge is accumulated on the solid electrode and ionic counter charge in the solution. This results in a capacitor with both high power and high energy density.
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How do supercapacitors differ from batteries? |
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Actually, the operating principles of supercapacitors and batteries are similar: pairs of electrodes are separated by an ionic conductive yet electrically insulating separator. However, during the charge and discharge cycling of electrons and ions no chemical reaction occurs in the EDLC, and thus an EDLC can undergo millions of charge and discharge cycles without derating, failure, or the need for recharging.
Under drain conditions, both a battery and an EDLC will undergo a voltage drop. Often the battery will not be able to supply the required power while still retaining its open circuit voltage, particularly where the battery must supply high power at short pulse widths; and a large load on the battery may decrease its useful energy, harming the battery and shortening its life span. In addition, batteries tend to be sensitive to low temperatures, which reduce their capacitance, as the slow kinetics of the chemical reaction in the battery increases its internal resistance. In both instances, coupling the battery with an EDLC provides superior power management in many short interval and high power applications.
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How do Cellergy supercapacitors differ from other EDLC capacitors? |
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Electrochemical double layer capacitors are not a new phenomenon,
but their relatively high prices have tended to limit their application to applications
which are less price-sensitive (PCMCIA cards, medical devices, GSM burst transmission).
Cellergy’s development of its patented new technology implementing screen printing
and low-cost raw materials avoids the time and expenses involved in winding of films,
pick and place for capacitor components, dry rooms and complex electrolyte
filling processes that characterize other commercially available supercapacitors.
Moreover, the use of screen printing permits rapid and cost-effective production of any capacitor
shape and size, and – unique in the marketplace – surface mount devices.
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What are the outstanding features of Cellergy supercapacitors? |
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High surface area carbon (2000 sqm per gram) coupled with electrochemical double layer effect lead to very high capacitance High energy density Multi-range voltage up to 12V Fast charge due to Low ESR (equivalent series resistance) High instantaneous current delivery Nearly infinite discharge/charge cycling Wide range of operating temperatures Environmentally friendly, RoHS compliant Low profile; Surface mountable; Wide footprint capability Offered in Low ESR and Low Leakage series
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Why are Cellergy supercapacitors particularly well-suited for mobile applications? |
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Cellergy EDLC supercapacitors are well-suited to meet both the economic
and the technological requirements of portable/mobile (nomad) digital applications,
such as cameras, cell phones and pagers, and mp3 players.
Economic:
Because these devices are high volume mass market products,
their manufacturers are under constant pressure to reduce cost and to reduce size/weight,
both accomplished through Cellergy’s screen printing technique and capability
for producing low footprint products of any needed size and shape.
Technical:
Nomad devices tend to be characterized by relatively low power needs to operate,
but high pulse power during transmission. During these pulse periods,
voltage sags with the increase of battery current,
battery efficiency and available capacity decrease, and operational life time is shortened.
Connecting a supercapacitor in parallel with the battery levels the load,
increasing device operating time and voltage drop during current pulses.
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Since Cellergy is a start-up, how can I have confidence that the product will perform as claimed? |
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Cellergy supercapacitors have been thoroughly tested,
not only in our own laboratories and by independent testing services,
but also by a wide variety of respected OEMs considering them for design-in.
Tests have covered:
Capacitance Leakage current ESR Load life Shelf life Humidity life Leg pull strength Surge voltage Temperature cycling Thermal shock Vibration Solderability
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