Green Patent Blog®

In April 2006 A123 Systems Inc. (A123), a Boston area lithium ion battery maker, brought a declaratory judgment action against Canadian utility Hydro-Quebec (H-Q) in federal court in Boston seeking declarations that A123 did not infringe U.S. Patent Nos. 5,910,382 (’382 Patent) and 6,514,640 (’640 Patent) and that the patents are invalid.  H-Q is the exclusive licensee of the ‘382 and ‘640 Patents.

The ‘382 and ‘640 Patents are entitled “Cathode materials for secondary (rechargeable) lithium batteries” and relate to host materials for use as electrodes in lithium ion batteries.  The patented materials provide a larger free volume for lithium ion motion that allows higher conductivity and therefore greater power densities.

In September 2006 A123 requested a stay of the Boston case pending the resolution of re-examination of the two patents in the U.S. Patent and Trademark Office (PTO).  The court dismissed the case without prejudice so the parties could subsequently move to reinstate it.

Also in September 2006, H-Q and the University of Texas (UT), which owns the ‘382 and ‘640 Patents, sued A123 for infringement of the patents in federal court in Texas.

This spring, after the PTO completed its re-examination of both patents, A123 asked the court in Boston to reopen its DJ action.  A123 argued that the Boston case should take precedence over the pending Texas action because it was the earlier filed case.

However, in a recent memorandum opinion (a123_memorandum.pdf) Judge Tauro of the U.S. District Court for the District of Massachusetts ruled that the Boston action could not be reinstated because A123 had failed to join the University of Texas.

Judge Tauro held that UT was a necessary party as the owner of the patents-in-suit because UT had not transferred all substantial rights in the patents to H-Q (the H-Q license contained some field of use restrictions).

Not only was UT not joined by A123, but UT could not be joined as a defendant in the Boston suit, the memorandum opinion held, because it is immune from suit.  Under the Eleventh Amendment, a federal court cannot hear a suit against a state without the state’s consent.

Last month A123 appealed (a123_notice_of_appeal.pdf) Judge Tauro’s order denying the motion to reopen the case (a123_order.pdf) to the Court of Appeals for the Federal Circuit (the appellate court that hears all patent appeals).

At least prior to A123’s appeal and Judge Tauro’s order, the Cleantech Litigation blog reported that the parties were trying to settle the suit. 

Eamex Corp. (Eamex) is a Japanese company that has developed a high energy density capacitor using a proprietary polymeric actuator with metal plating that serves as an electrode.

The capacitor and methods of making it are covered by U.S. Patent No. 7,169,822 (’822 patent).  The ‘822 patent is directed to a polymeric actuator (1) comprising an ion-exchange resin (2) in the form of a flat plate or film and metal electrodes (3a, 3b) attached to the surface of the resin by chemical plating techniques.

Lead wires (4a, 4b) provide an electrical connection between the electrodes (3a, 3b) and a power source (5).  The metal electrodes (3a, 3b) are insulated from each other, and application of a potential difference between the electrodes causes the ion-exchange resin product to bend or deform.

According to Eamex’s web site and this Greentech Media article, the electrodes of the patented actuator have greatly increased surface area, and the energy density per unit volume reaches up to 600 Wh/L, which is equivalent to that of a lithium-ion secondary battery.

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).  

Ultracapacitors are used to store energy in applications that require storage of large amounts of energy and rapid energy discharge, such as electric vehicles. 

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.

Boston-Power, a Massachusetts advanced battery company, makes lithium-ion batteries that charge faster and last longer than conventional lithium-ion batteries. 

Last month, Boston-Power announced that Hewlett-Packard (HP) would be its first customer and would offer its Sonata battery as an upgrade option in select HP notebook PCs in early 2009.  (see the greentechmedia piece here and the New York Times article here)

Boston-Power owns several U.S. patent applications covering its battery technology, including U.S. Application Pub. Nos. 2008/0008928 (’928 application) and 2008/0008933 (’933 application).

Conventional lithium-ion batteries have a cathode (an electrode that circulates electrons) made of lithium cobalt.  The ‘933 application is directed to a blend of two or more different types of cathode materials in the positive electrode which enables manufacturing of larger cells than conventional lithium-ion batteries that use lithium cobalt alone. 

According to the ‘933 application, increasing capacity through these larger cells is a better solution than increasing the number of cells, which raises the probability of over-charge or over-discharge.

The ‘928 application is directed to a battery integrated with a current interrupt device (CID).  When lithium-ion batteries are improperly charged, exposed to high temperatures, or are short circuited, they may produce gas, and the pressure increase can be dangerous. 

CIDs protect against excessive internal pressure increases in batteries by interrupting the current path when pressure increases.  However, according to the ‘928 application, CIDs incorporated within batteries take a lot of space and limit battery capacity.

The invention of the ‘928 application is a battery in which at least a portion of the CID (28) may be located external to the battery can (21) because the CID is in electrical communication with the battery can.  Specifically, at least one of the cell casing (22) and the lid (24) of the battery can (21) are in electrical communication with the second electrode (14) of the battery (10) through the CID (28).

Boston-Power’s technology provides significant advantages over the competition.  According to the greentech media article, Boston-Power’s batteries take a half hour to charge to 80% capacity, instead of 2 hours for an ordinary battery. 

Also, the batteries can last about 1,000 charging cycles (i.e. three years), before the charging capacity becomes substantially diminished, whereas conventional lithium-ion batteries go about 300 cycles or fewer.  As a result, HP will provide a 3-year warranty with the Sonata battery.

I saw this interesting post on Green Light about a presentation at the recent Copenmind conference by two European Patent Office (EPO) patent examiners about clean tech patent filings in the EPO. 

The examiners noted that the two hottest areas for clean energy patent filing in Europe are fuel cells and wind power.  According to the presentation, about half of clean tech patent filings from 1998 to 2007 relate to fuel cell technology, with wind being the fast growing category, increasing by over 30% each year.

This is consistent with U.S. clean tech patents granted, as reported in the second quarter 2008 installment of the Clean Energy Patent Growth Index (see my previous post here). 

The bulk of the European wind technology innovation is coming out of Germany, which accounts for 39% of the EPO wind applications. 

The U.S. is second with 16% of the wind patent filings, and there’s plenty of room for wind technology companies to grow in the U.S. - according to the Green Light post, the U.S. gets only 1% of its power from wind.