| The
Nesscap pseudocapacitor has a structure
and characteristics similar to the Electric
Double Layer Capacitor (EDLC), which together
represent the two main ultracapacitor technologies.
The pseudocapacitor differs from the EDLC
in that it uses a metal oxide rather than
an activated carbon for electrode material.
Applying its proprietary pseudocapacitor
technology, Nesscap has developed a credit
card size product with 30 watts of power.
Announced during Ninth International Seminar
on Double Layer Capacitors in December
1999, the pseudocapacitor was targeted
as a high pulse power device for satellite
communications. Now, Nesscap has shifted
its R&D efforts to increase the pseudocapacitor's
energy density by using organic electrolyte
and develop it as a successor to the EDLC
as the premier ultracapacitor device. The
in-depth knowledge accumulated from testing
this technology to its extremes has enriched
Nesscap's capability to offer a boundless
range of competitive pseudocapacitor products
tailored to specific applications.
A critical element of
Nesscap pseudocapacitor technology and
a major focus of R&D involve the development
of a new low-cost, high performance metal
oxide. The metal oxide currently used in
the pseudocapacitor has a specific capacitance
(F/g) approximately 90% that of the activated
carbon used in EDLC. However, a newly patented
material developed by Nesscap and undergoing
testing shows a specific capacitance 20%
greater than the EDLC electrode. This higher
capacitance represents a more cost-effective
product. In addition, the current metal-oxide
has a cost to energy ratio of only 80-90%
to that of activated carbon; the properties
of the new metal oxide makes this advantage
even more profound.
The pseudocapacitor has
greater potential for a higher energy density
than the EDLC. The activated carbon in
the EDLC utilizes surface area for energy
storage, thus physically limiting potential
energy density. The metal oxide technology
of the pseudocapacitor utilizes an electrochemical
reaction similar to battery technology
for energy storage, thus improving potential
energy density. Since the pseudocapacitor
uses a dense metal oxide as the electrode
material, the load of the oxide is three
times that of the EDLC for the same coated
area. With this advantage, pseudocapacitor
cell needs to be only 60% in volume as
compared to an EDLC of the same capacitance.
Conversely, it also means the pseudocapacitor
holds 80% more energy than the equivalent-size
EDLC. This appeals to niche applications
such as handheld products where space is
a premium and this additional benefit will
command premium prices.
Finally, the pseudocapacitor
uses the same manufacturing processes and
facilities as EDLC production; the only
significant distinction is that the pseudocapacitor
electrode replaces the EDLC electrode.
Using EDLC production facilities, Nesscap
started to produce produce radial products
in the range of 20-120 Farad. This compatibility
is a considerable advantage, leading the
way for the Nesscap pseudocapacitor to
supplant the EDLC as the next generation
ultracapacitor with relative ease and minimal
additional investment.
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