Ultra capacitors | Electronics Seminar Topic
Ultra capacitors
General Electric engineers experimenting with devices using
porous carbon electrodes first observed the EDLC effect in 1957. They
believed that the energy was stored in the carbon pores and the device
exhibited "exceptionally high capacitance", although the mechanism
was unknown at that time.
General Electric did not immediately follow up on
this work. In 1966 researchers at Standard Oil of Ohio developed the modern
version of the devices, after they accidentally re-discovered the effect while
working on experimental fuel cell designs. Their cell design used two layers
of activated charcoal separated by a thin porous insulator, and this basic
mechanical design remains the basis of most electric double-layer capacitors.
Standard Oil also failed to commercialize their invention,
licensing the technology to NEC, who finally marketed the results as
“supercapacitors” in 1978, to provide backup power for maintaining computer
memory. The market expanded slowly for a time, but starting around the
mid-1990s various advances in materials science and refinement of the existing
systems led to rapidly improving performance and an equally rapid reduction in
cost.
The first trials of supercapacitors in industrial applications were
carried out for supporting the energy supply to robots. In 2005 aerospace
systems and controls company Diehl Luftfahrt Elektronik GmbH chose supercapacitors
to power emergency actuation systems for doors and evacuation slides in
airliners, including the new Airbus 380 jumbo jet. In 2005,
the ultracapacitor market was between US $272 million and
$400 million, depending on the source. As of 2007 all solid state
micrometer-scale electric double-layer capacitors based on advanced superionic
conductors had been for low-voltage electronics such as deep-sub-voltage
nanoelectronics and related technologies (the 22 nm technological node of CMOS
and beyond).
