Compact High-Output Energy Device

Improving Performance of Battery-Powered Equipment With High-Capacitance, High-Voltage, Low-Resistance and Compact Electrical Double Layer Capacitors


Murata's compact electrical double layer capacitor features high capacitance and high output.
Used as a supplementary power supply for portable battery-powered equipment, it can reduce battery load and support high-output features unattainable by battery power.



Generally, electrical double layer capacitors are referred to by their acronym, EDLC. With their supersized capacitance, EDLCs are also known as supercapacitors or ultracapacitors. Their capacitance is a few thousand times that of ceramic capacitors, and a few hundred times that of aluminum electrolytic capacitors. EDLC has a smaller internal resistance and a longer charge/discharge cycle life compared with batteries. EDLCs were conventionally coin-type and were used for low-output applications such as mobile phone memory backup.

Electrical double layer capacitor

Electrical double layer capacitor

Murata developed compact, high-capacitance, high-voltage and low ESR (equivalent series resistance) EDLCs optimizing the design and materials of a technology introduced through a technological alliance with Australian CAP-XX Ltd. in 2008. We have optimized the pulse response to expand the range of potential applications capitalizing on their high capacitance, and realized low ESR over a wider temperature range by reducing the rise in ESR under low temperatures. Thus a large amount of energy stored with high capacitance and high voltage may be output at a lower loss over wide temperature and frequency ranges.

These characteristics allow EDLC to function as a peak output supplementary power supply for battery-powered equipment and compact power supplies with output limitations. For example, an EDLC in a high-luminance LED flash system can instantaneously supplement high output to a flash over 30W for digital video cameras and digital cameras. EDLCs can realize a similar feature in high-definition smartphones without overtaxing their batteries.

Murata plans to develop smaller and lower-ESR EDLCs to aid higher performance and more efficient energy usage in many more battery-powered equipment and compact power supplies.


Specification example

  Single cell Double cell
Nominal capacitance 700mF 350mF
ESR 30mΩ 30mΩF
Rated voltage DC 2.7V DC 5.5V
Size 18.5mm×20.5mm
Thickness 1.3mm 2.8mm
Energy density 1.5Wh/L 1.4Wh/L
Power density 128kW/L 119kW/L

Characteristics of Murata's EDLC

Characteristics of Murata's EDLC


Construction

Large capacitance and low resistance realized by high electrode density from monolithic construction and optimization of electrochemical system

Construction

Application example (for high-luminance LED flash system)

Lights for 33msec at the current value of 8A (2A per LED x 4)
Capable of effective LED-based camera flash performance

Application example (for high-luminance LED flash system)

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