Reticle, Inc. (Reticle) is a Los Altos, California startup that has developed a new carbon electrode material and process of making the material, which is ideal for use in ultracapacitors (see New Energy and Fuel article here). Â
Ultracapacitors are used to store energy in applications that require storage of large amounts of energy and rapid energy discharge, such as electric vehicles.Â
Ultracapacitors store energy through movement of electrons, i.e., separation of charged species as positive ions called cations migrate to a negatively charged electrode (anode), and negative ions called anions move to a cathode, or positively charged electrode. The more ions that are attracted to their respective electrodes, the more energy the ultracapcitor stores.
There are two known ways to increase the number of ions attracted – boosting voltage and increasing the surface area of the electrodes. This is where Reticle comes in. The company’s patented process produces electrodes from granular activated carbon which have much greater surface area than any known electrode materials presently offered (see the inventor’s cogent explanation here).
Whereas typical processes consolidate carbon by pressing it into thin films, Reticle’s process applies pressure to the carbon material from all sides and obviates the need to add binders or adhesives. This allows for better automation than other capacitor material, so the material can be machined into any size with lots of conductive surface area.
This picture shows one unique aspect of the resulting material, which the company calls “Reticle Carbon”:
That is, not only is the surface area greater, but all of the carbon particles remain connected to ensure that all the charge is distributed across the entire surface area of the material.
This table compares the specs and capabilities of two Reticle capacitors with those of a couple of other commercially available products:
Reticle Carbon also is a good material for desalination applications because the higher mass and surface area allows the acquisition of more ions before a regeneration step would be required.
Reticle’s manufacturing process and resulting carbon material are protected by a family of four U.S. patents: U.S. Patent Nos. 6,350,520 (claims granular active carbon material made by a high temperature and pressure process), 6,511,645 (claims a process for producing carbon material by consolidating amorphous carbon using elevated temperature compression), 6,544,648 (claims a processed carbon material consolidated under elevated temperature and pressure) and 6,787,235 (claims a processed carbon material consolidated in a hot isostatic press under elevated temperature and pressure).
According to Jack Mastbrook, who does marketing development for Reticle, the company is currently seeking funding to ramp up operations.  But Mastbrook told me that Reticle already has a deal in place to sell its activated carbon to a major consumer products manufacturer, which plans to test the material as a replacement for batteries in its products.
