A new current collector

Increased service life of lithium-ion battery or supercapacitor

The problems with existing technologies

Device

The current collector removes current from the supercapacitor (or battery). Collectors on the market are usually made of aluminum or copper foil.

Production

During the production cycle, even before the collector is coated with the electrode, they are instantaneously coated by an oxide film when they come into contact with the air, since they are prone to corrosion.

Disadvantages

Further down the line this film increases the electrical loss of the supercapacitor, as well as significantly reducing its electrical conductivity, reliability and durability.

Cause

The cause is found in the poor level of adhesion of the collector – i.e. in the strength of connection of the electrode with the aluminum foil, and also in the dielectric property of aluminum oxide which has a great electrical resistance.

The contact resistance of the oxide layer on the aluminum foil is 8 Ohms/cm².

Improved collector

Device

Normally chemically etched foil is used to improve adhesion. We do not need this since we use an inert material that does not react with the electrolyte for the protection of the aluminum foil from oxidation and degradation in the electrolyte: this is also carbon!

Decision

The carbon coating can protect aluminum only when the coating is dense with no open pores that might let the electrolyte get past to the aluminum.
Thus, two types of carbon coating must be applied to the aluminum foil – one dense applied directly to the aluminum, and a second coating – with a high pore content – the active electrode.

Result

The contact resistance of the carbon layer on the aluminum foil is 26,000 times less – 0.0003 Ohms/cm².

Energy loss in the supercapacitor is greatly reduced. Our technology allows for the creation of a collector with carbon coating without any of the old shortcomings and with lower production costs.

 

 

High strength conductive carbon coating improves the properties of the aluminum foil current collector and provides:

 

 

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Minimum internal resistance of the capacitor which is obtained by replacing the oxide film on the aluminum with a very conductive carbon coating.

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Improved adhesion of the active electrode material to the current collector.

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Increased mechanical strength of the foil.

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High charge and discharge currents for the capacitor and battery.

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Increased lifetime of a lithium-ion battery or supercapacitor.

Total energy storage system market bn $

%

The annual average incremental growth for the energy storage system market

Cost of the carbon coating $

The market value of the foil and the current collector $

Our second technology is the creation of a new electrode


Electrode improvement in our technology allows for increased density of stored energy in the battery and supercapacitor.

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