Archive for the ‘Energy Storage’ category

Optimizing Green Patent Protection: A Study in Energy Storage Service

December 3rd, 2013


Stem is a Millbrae, California, startup that sells and leases its battery energy storage system, which is marketed as a way to reduce consumers’ energy bills.  Specifically, the company makes a lithium-ion battery connected to analytics software that determines the best times to draw energy from the battery, thereby reducing electricity demand charges.

As more demand side energy efficiency / smart grid technologies are being offered as services (with leasing of equipment rather than sale), I’ve been thinking about what this might mean for green patent drafting.  One of the things patent prosecutors consider when preparing a patent application is how to draft the claims to ensnare as many different potential infringers in the chain of commerce as possible.

On this score, it is important to keep in mind the acts that can constitute infringement, viz., making, using, selling, offering for sale, and importing into the United States.

In conventional scenarios, the competitors that could be infringers are typically manufacturers that make, offer for sale, and sell competing products as well as the end users of the products.  There could be distributors in the chain too, but these may or may not be viable infringement targets because of the patent exhaustion doctrine, which holds that an unrestricted authorized sale of a patented product “exhausts” the patent holder’s rights to control the use and sale of the product.

Taking Stem’s battery energy storage as a service as an example, the company owns at least one U.S. patent and one pending patent application relating to its technology.  Both are entitled “High speed feedback adjustment of power charge / discharge from an energy storage system” and are Publication No. 2013/0207591 (‘591 Application), which is a continuation of U.S. Patent No. 8,350,521 (‘521 Patent).

Generally speaking, the ‘521 Patent and ‘591 Application are directed to smart charge systems and power management methods in which power demand load data and variable generator power data are synchronized in time and used to provide optimal charge/discharge instructions to an energy storage unit.

The simplest infringement scenario, of course, would be competing manufacturers that make and sell products that infringe the ‘521 Patent by their manufacturing and sales activities; there also could be end users who infringe by their use.  But what about a competitor that simply leases infringing systems to end users? 

This hypothetical competitor has situated itself at a spot in the commercial chain where it may be able to avoid a charge of direct infringement because it is not making, selling, offering for sale, or importing an infringing product.  Depending on how the claims of the relevant patent are written, this competitor may not be using the product either.  It’s conceivable that the end users may be the only direct infringers in this scenario.

However, the patentee may have a case for inducing infringement against a competing storage as a service lessor if the patent claims are drafted carefully.  Section 271(b) of the patent statute provides that anyone who “actively induces” infringement of a patent is an infringer.  This means that someone who himself does not infringe, but induces another to do so (e.g., by providing a product with advertising or instructions about an infringing use), may be held liable for inducement, a form of secondary liability for patent infringement.

The ‘521 Patent (and the ‘591 Application) contains both system and method claims:  claims directed to a smart charge system and claims directed to a method of power monitoring and management.  Independent claim 1 of the ‘521 patent is directed to a smart charge system including a premise sensor for measuring premise power information, a variable generator sensor for measuring generator power information, an energy storage unit, and a control computer that receives synchronized information from the sensors and energy storage unit and provides charge/discharge instructions.

It’s possible that an end user of the smart charge system might, through use of the system, be a direct infringer of claim 1 of the ‘521 Patent and the company leasing the system could be liable for inducing the infringement of the end user.

A better candidate for inducement is independent claim 10 of the ‘521 Patent because this is a method claim:

10. A method of power monitoring and management comprising:

providing, at a controller, a desired limit load;

receiving, at the controller, power demand load information;

receiving, at the controller, variable generator power information; and

transmitting, from the controller to an energy storage unit, a charge/discharge instruction based on the desired limit load, the power demand load information, and the variable generator power information.

Even if the end user isn’t using the whole system with all the components recited in claim 1, or if a different system is being used, the storage as a service lessor could still be liable for inducing infringement if it directs or instructs the end user to carry out the method steps recited in independent claim 10.

Having method claims in a patent provides better protection and greater flexibility for enforcement by exposing more players and activities in the commercial chain to potential infringement liability.  As clean tech companies continue to explore new business models, careful green patent claim drafting will become more important to ensure optimal protection.



Patent Pending Velkess Flywheel with Gimbal Remains Resonantly Undisturbed

April 29th, 2013

A previous post reported on the acquisition of Beacon Power, formerly the largest flywheel player, after the company went bankrupt.

One of the technical hurdles faced by designers of these whirling rotational energy storage devices is that spinning masses have a natural “wobble.”  Most flywheel designers have employed expensive bearings, magnets, and materials in attempts to minimize this wobble to better align the flywheel’s axis of rotation with the rotation of a generator.

Enter Velkess, a Silicon Valley developer of new flywheel technology, which has invented a self-stabilizing design.  Velkess owns U.S. Patent Application Publication No. 2012/0096984, entitled “Flywheel system” (‘984 Application).

The ‘984 Application is directed to a flywheel system in which the wheel is suspended in a non-symmetric damped gimbal system (9) (a gimbal is a pivoted support that allows the rotation of an object about a single axis, commonly used in gyroscopes).  The shaft of a motor/generator (20) is attached to a flexible coupling (13), which is also attached to a rigid shaft (14).

 The rigid shaft (14) is attached at its other end to a super-circular bare filament flywheel rotor (16).  The shaft (14) can transmit high levels of torque and will not suffer the destabilizing displacement common in traditional flywheels.

According to the ‘984 Application, the invention allows one axis of the gimbal to dampen the resonant frequencies in the other axis:

[T]he non-symmetric damped gimbal system 9 of embodiment 15 has two different resonant base frequencies established by the differing lengths of the pendulum that each axis 10 and 11 create. This allows one axis 10 or 11 of the non-symmetric gimbal 9 to damp the resonant frequencies in the other axis 10 or 11.

As explained nicely by Chris Nelder in a recent Scientfic American piece, this feature minimizes resonant disturbances and permits more control of the device:

The gimbal in the Velkess is asymmetrical, so the two axes of rotation—the flywheel axis as well as that of the rotor, which drives the brushless, inducting DC motor—are not on the same plane, and have different periods of frequency. This dampens the resonance effects that make traditional flywheels hard to control (a resonant disturbance in one of the planes can intensify until the device shatters). With the gimbal, resonance in one plane is translated into the other, which is nonresonant at the same frequency. Accordingly, only very loose engineering tolerances—about one sixteenth of an inch—are required to build the device.

According to Nelder, the Velkess flywheel has significant advantages over previous devices like those made by Beacon Power, including slower, longer discharge of stored energy, and scalability.  More info on the Velkess technology can be found on the company’s technology page.

Leyden Energy Batteries Live Longer with Lithium-imide Electrolytes

January 31st, 2013

Leyden Energy (Leyden) is a Silicon Valley company that has developed a lithium ion battery that uses imide salts as electrolytes instead of the more commonly used PF6-based electrolytes.  Formerly known as Mobius Power, Leyden built it Li-imide battery platform on seed technology from a patent acquired by DuPont.

In addition to the DuPont patent, Leyden owns at least one U.S. patent and at least six pending applications.  U.S. Patent No. 8,221,915 is entitled “High performance lithium or lithium ion cell” (‘915 Patent) and directed to lithium ion electrochemical cells comprising a case (100), a cover (200), which is the positive terminal, and an insulating ring (300) between the case and the cover.

A negative tab (400) connects the anode current collector to the cover, and a positive tab (500) connects the cathode current collector to the cover.  The cell also includes a positive terminal (550), a cathode (600), an anode (700), a separator (800), and an electrolyte solution inside the pores of the electrodes and separator.

The cathode (600) comprises an active material and a current collector made of aluminum foil with a protective, conductive coating, and the anode (700) comprises an active material and a copper foil current collector.

The crux of the ‘915 Patent is the invention of a way to reduce the corrosion typically caused by lithium imide salts so their properties of superior thermal and hydrolytic stability can be harnessed to extend the life of the battery.  According to the ‘915 Patent, Leyden’s unique combination of conductive protective coating and anti-corrosion additives achieves this goal:

The following examples describe and explain how synergy of conductive protective coating and corrosion inhibiting additives results in [the] possibility of using thermally stable salts described herein to achieve long battery cycle life with little degradation.

In particular, an electrolyte solution of Lithium bis(Trifluoromethanesulfonyl)Imide (LiTFSI) with the additive lithium bis(oxalato)borate significantly reduced corrosion over a one week testing period:

The corrosion of the protected samples did not occur with the whole duration of the test (one week).  This surprising finding shows the synergetic effect of using the protective coating and the corrosion inhibiting additive allows reduction or prevention of corrosion of the current collector corrosion.

This Greentech Media article notes Leyden’s claims that the lithim-imide electrolyte allows temperatures greater than convention lithium-ion batterys, longer cycle life, and higher charge density, and the follow-up piece reports on the company’s latest funding round.

Storage in the Mist: LightSail’s Patented CAES Tech

December 7th, 2012


LightSail Energy (LightSail) is a Berkeley, California, company that has developed compressed air energy storage technology which may be used for grid-scale storage. 

The company’s central innovation is the injection of a mist of water spray into a compressed air system so the spray rapidly absorbs the heat energy of compression and provides the energy during expansion.

According to Cleantech PatentEdge™, LightSail owns at least 52 US, international, and European patents and published applications.  U.S. Patent No. 8,240,142 (‘142 Patent) is one of a family of patents relating to the company’s compressed air energy storage system.

The ‘142 Patent is entitled “Compressed air energy storage system utilizing two-phase flow to facilitate heat exchange” and directed to a compressed air energy storage system (20) including a cylinder device (21) defining a chamber (22), a piston device (23) in the chamber, and a pressure cell (25).  The cylinder (21) and pressure cell (25) together form a one stage reversible pressure compression/expansion mechanism (24).

Air enters the system (20) via pipe (10), passes through a filter (26) and enters the cylinder chamber (22) via pipe (30) where it is compressed by the action of the piston (23).  Before compression begins, a liquid mist is introduced into the chamber (22) using an atomizing nozzle (44).  The volume of mist injected into the chamber (22) is predetermined to be the volume required to absorb all the heat generated during that piston stroke.

As the mist condenses, it collects as a body of liquid (49e) in the cylinder chamber (22).  The compressed air/liquid mixture is then transferred into the pressure cell (25) through outlet nozzle (11) via pipe (51). 

According to the ‘142 Patent, that is when the critical heat exchange occurs, followed by storage of the air:

In the pressure cell 25, the transferred mixture exchanges the captured heat generated by compression to a body of liquid (49f) contained in the cell.  The air bubbles up through the liquid and on to the top of the pressure cell, and then proceeds to the air storage tank 32, via pipe 33.

According to this Greentech Media piece, LightSail’s system is more efficient because it captures and stores both the mechanical energy and the thermal energy used in compressing air.  The article reports the company has received a recent funding round by some big name investors, including Bill Gates and Khosla Ventures.

Isentropic’s Pumped Heat Electricity Storage Runs Hot and Cold

June 28th, 2012

Isentropic is a UK company that has developed an energy storage system called Pumped Heat Electricity Storage (PHES).

Isentropic owns several international and U.S. patents and applications.  U.S. Application Publication No. 2010/0257862 (‘862 Application) describes and claims the PHES technology.

Entitled “Energy storage,” the ‘862 Application is directed to an energy storage system (10) comprising compressor/expander means (20) including a compressor (21), an expander (22), and power input/output means (40).

The energy storage system (10) also includes a first heat storage means (50), a second heat storage means (60), high pressure transfer means (70, 71) and low pressure transfer means (80, 81).

To charge the system (10), a low pressure gas enters the compressor (21) through inlet (23) and passes into a compression chamber (24).  The low pressure gas is compressed by a compression piston (25) and transferred via the high pressure transfer means (70) to the first heat storage means (50) where it transfers thermal energy to the first thermal store (53).

The gas then passes through the high pressure transfer means (71) and enters the expander (22) through inlet (27).  The gas is then expanded in the expansion chamber (28) and is transferred by the low pressure transfer means (81) to the second heat storage means (60) where it receives thermal energy from the second thermal store (63).

Finally, the gas passes through the low pressure transfer means (80) and can start the process again by entering the compressor (21).

According to Isentropic’s PHES technology web page, each heat storage means contains mineral particulates as a storage medium to interact with the pumped gas.

The company says the PHES system provides very high (72-80%) round trip efficiency comparable with pumped hydro, high reversibility, i.e., the system can function as both an engine and a heat pump, and no geographical restraints.

Isentropic should be able to showcase all of these advantages soon.  This GTM piece reports that a UK public-private partnership called the Energy Technologies Institute is investing $22 million to build a full-scale PHES demo system.

Newton Would Be Proud: Gravity Power’s Technology Has Great Potential

April 9th, 2012


By spending years in the flywheel industry, Jim Fiske learned a great deal about grid-scale energy storage and its true requirements. After determining that flywheels were not the best option, he and the investor of his flywheel company founded Gravity Power. Gravity Power’s technology has the potential to change energy storage worldwide.

Presently, pumped hydro provides nearly all grid-scale energy storage, but requires vast quantities of water, two very large reservoirs, and extreme differences in land elevation. It can be difficult to fulfill all three necessary parameters, and a big plant can cost over a billion dollars with delayed financial returns.

Gravity Power’s technology is similar to the concept behind pumped hydro, but overcomes many of pumped hydro’s limitations. Each Gravity Power Module is a closed system that operates underground. Thus, once the device is initially filled with water, no additional water is needed. A 40MW unit is 30 meters in diameter and 500 meters deep, while a 250 MW unit is 80 meters in diameter and 500 meters deep.

To generate energy, the piston drops, and forces the water through a Francis-style pump-turbine that drives a motor/generator. To store energy, energy from the grid causes the pump to force water down the pipe and lift the piston.  The following figure from Gravity Power’s website illustrates the process:

According to Fiske, Chief Technology Officer and Founder of Gravity Power, the company is currently doing a deep cost-analysis of the technology. The bigger the unit, the more cost-effective it becomes. Mr. Fiske anticipates that a 250 MW storage device would cost approximately 250 million dollars.

The company is currently seeking additional investors, and countries including Germany, South Africa, China, and India are interested in utilizing the technology. Utilization of this type of energy storage could help compensate for the variability of wind power and other renewable energy generation techniques.

The company currently has patent applications for its technology all over the world. According to Cleantech PatentEdge™, LaunchPoint Technologies, from which Gravity Power was spun out, owns seven U.S., International, and European patents and applications.

U.S. Patent Application Publication No. 2009/0193808 (‘808 Application) lists LaunchPoint as the owner of record. Entitled “System and method for storing energy,” the ‘808 Application relates to an energy storage system in which electricity can be generated by gravitational movement of a slidable piston.  The claims of the ‘808 Application were recently allowed, and the company anticipates that a patent will issue in the next few weeks, with several others in the works.

The company’s goal is to complete a small-scale demonstration module first to verify the technology. According to Mr. Fiske, one of the great benefits is that the units can be easily built by civil engineering companies all over the world because no exotic materials are needed – just concrete and steel. The technology is based on existing technologies, but this will be the first time the pieces will be combined in this particular way.

“A big advantage of our technology is its level of efficiency. Efficiency is expected to exceed that of pumped hydro, and be as high as 83%. In addition, it is quite feasible to build many gigawatts of storage per year due to the ease of construction of the Gravity Power Modules,” stated Mr. Fiske. Sounds like an energy storage device with great potential.

* Rosemary Ostfeld is a contributor to Green Patent Blog.  Rosemary recently completed both her undergraduate and graduate education at Wesleyan University in Middletown, Connecticut.  She double majored in Biology, and Earth & Environmental Sciences as an undergraduate, and received her Master’s in Earth & Environmental Sciences.

Valence Scores Victory in European Battery Patent Appeal

March 26th, 2012

Valence Technology is an Austin, Texas, company that develops and manufactures long-life lithium iron magnesium phosphate batteries. 

Valence recently won a victory in the European Patent Office (EPO) Opposition Board when the Board dismissed an appeal of a decision revoking a European patent held by rival Hydro-Quebec (HQ).

The EPO initially granted European Patent Number 0904607, entitled “Cathode materials for secondary (rechargeable) lithium batteries” (‘607 Patent) to the University of Texas; the patent is now owned by HQ. 

Valence challenged the patent grant in an opposition proceeding filed in 2005.  The EPO Opposition Board revoked the grant in December 2008 because the patent lacked novelty (EPO_Revocation).  HQ appealed that decision. 

Last month the EPO Opposition Board dismissed HQ’s appeal, resulting in cancellation of the patent.

The ‘607 Patent is a European relative of U.S. Patents Nos. 5,910,382, 6,514,6407,955,733, 7,960,058 and 7,964,308, entitled “Cathode materials for secondary (rechargeable) lithium batteries” (Cathode Materials Patents).

The Cathode Materials Patents relate to host materials for use as electrodes in lithium ion batteries.  In particular, the patents are directed to a synthesized cathode material containing a compound with an olivine structure comprising the general formula LiMPO4 where M is iron, manganese, nickel or titanium.

According to the Cathode Materials Patents, these cathode materials provide a larger free volume for lithium ion motion that allows higher conductivity and therefore greater power densities.

Valence and HQ are not strangers to litigation involving the Cathode Materials Patents.  Read previous posts here and here about those cases, which the parties settled as part of a cross-licensing deal in October of last year.

David Gibbs is a contributor to Green Patent Blog.  David is currently in his third and final year at Thomas Jefferson School of Law in San Diego.  He received his undergraduate degree in Geology from the University of California, Berkeley.

Getting Charged Over Batteries: Envia Announces 400Wh/kg Li-Ion Battery

March 15th, 2012

Envia Systems is a Newark, California, company that develops high performance, low cost lithium-ion energy storage solutions. 

In a recent Press Release, Envia announced that they have achieved a world record 400 Watt-hour/kilogram (Wh/kg) energy density for rechargeable lithium-ion batteries.  This milestone comes after much development and testing:

Dr. Sujeet Kumar, Envia Systems co-founder said “Since the inception of Envia, our product team has worked tirelessly and logged over 25 million test channel hours to optimally develop each of the active components of the battery: Envia proprietary Si-C anode, HMCR [High Capacity Manganese Rich] cathode and EHV [Envia’s High Voltage] electrolyte.”

The anode, cathode and electrolyte materials appear to be described in several patent applications owned by Envia.

The patent applications describing Envia’s cathode are U.S. Patent Application Publication No’s:

2010/0086853 (‘853 Application), entitled “Positive Electrode Materials for Lithium Ion Batteries Having a High Specific Discharge Capacity and Processes for the Synthesis of These Materials”;

2011/0076556 (‘556 Application), entitled “Metal Oxide Coated Positive Electrode Materials for Lithium-Based Batteries”;

2011/0111298 (‘298 Application), entitled “Coated Positive Electrode Materials for Lithium Ion Batteries”; and

2010/0151332 (‘332 Application), entitled “Positive Electrode Materials for High Discharge Capacity Lithium Ion Batteries”

Figure 1 below is a depiction of  a battery taken from the ‘853 Application.  The Figure depicts a battery (100), a negative electrode (102), a positive electrode (104), and a separator (103) between the positive electrode (104) and negative electrode (102).

Envia’s patent-pending process involves applying excess lithium, in the form of lithium manganese oxides, on the cathode to increase overall energy density. According to the ‘298 Application:

It is believed that appropriately formed lithium-rich lithium metal oxides have a composite crystal structure in which the excess lithium supports the formation of an alternative crystalline phase.  For example, in some embodiments of lithium rich materials, a Li2MnO3 material may be structurally integrated with either a layered LiMnO2 component or similar composite compositions with the manganese cations substituted with other transition metal cations with appropriate oxidation states.

At least one of Envia’s patent applications describes an anode: Patent Application Publication No. 2011/0111294, entitled “High Capacity Anode Materials for Lithium Ion Batteries” (‘294 Application).

According to the ‘294 Application:

Desirable high capacity negative electrode active materials can be based on nanostructured silicon materials and/or composites with nanostuctured carbon materials.  In particular, nanostructure silicon can comprise elemental silicon nanoparticles and/or porous elemental silicon, as well as corresponding silicon alloys and composites thereof … carbon coatings can be applied over the silicon-based materials to improve electrical conductivity, and the carbon coatings seem to also stabilize the silicon based material with respect to improving cycling and decreasing irreversible capacity loss.

At least two patent applications describe Envia’s electrolyte:

2011/0052981 (‘981 Application), entitled “Layer-Layer Lithium Rich Complex Metal Oxides with High Specific Capacity and Excellent Cycling”; and

2011/0017528  (‘528 Application), entitled “Lithium Ion Batteries with Long Cycling Performance”

The common theme throughout all the patent applications is the effect small changes in battery chemistry and materials have on performance.  According to the ‘556 Application:

It has been found that relatively small amounts of metal oxide coating on a lithium rich metal oxide active material can provide desirable improvements in lithium-based battery performance with respect to both specific discharge capacity and cycling.

Envia’s batteries have environmental benefits in addition to their ability to store a record amount of energy.  According to the ‘853 Application:

These compositions [in the batteries] use low amounts of elements that are less desirable from an environmental perspective, and can be produced from starting materials that have reasonable cost for commercial scale production.

Envia’s new battery technology was tested by the Electrochemical Power Systems Department at the Naval Surface Warfare Center in Crane, Indiana.  The test results confirmed Envia’s claims regarding its batteries demonstrating an energy density between 378-418 Wh/kg. 

Envia’s Systems Chairman and CEO, Atul Kapadia noted the potential implications for electric vehicles:

In an industry where energy density tends to increase five percent a year, our achievement of more than doubling state-of-art energy density and lowering cost by half is a giant step towards realizing Envia’s mission of mass market affordability of a 300-mile electric vehicle.

In fact, drivers may see Envia batteries in future General Motors electric vehicles.  General Motors Ventures LLC invested $17 million in Envia in a 2011 equity investment round and, in a separate agreement, secured the right to use Envia’s cathod material in GM EVs.

David Gibbs is a contributor to Green Patent Blog.  David is currently in his third and final year at Thomas Jefferson School of Law in San Diego.  He received his undergraduate degree in Geology from the University of California, Berkeley.

Green Patent Acquisitions: Private Equity Firm Snaps Up Beacon Power’s Flywheels

February 22nd, 2012

Beacon Power is a Massachusetts company that makes flywheel-based energy storage systems. 

Rockland Capital, a private equity firm, recently purchased Beacon Power, including a Stephentown, New York, flywheel plant project.  The purpose of the project is to allow excess energy from the grid to be stored at the plant, and then re-emitted at a later time when energy demand increases.

According to Cleantech PatentEdge™, Beacon Power Corporation is listed as the owner of record on 69 U.S., European, and international (PCT) patents and published applications.

U.S. Patent No. 6,614,132 (‘132 Patent), entitled “Multiple flywheel energy storage system,” describes an energy storage system comprising a plurality of flywheel systems, while U.S. Patent No. 8,008,804 (‘804 Patent) is entitled “Methods, systems and apparatus for regulating frequency of generated power using flywheel energy storage systems with varying load and/or power generation” and describes how frequency can be regulated using flywheels.

In the invention of the ‘132 Patent, each flywheel energy storage system unit (100) generates kinetic energy by spinning at a constant rate and drives a motor/generator (104).  According to Beacon’s web site, the company’s Smart Energy 25 flywheel can rotate at speeds of up to 16,000 rpm.

A bi-directional inverter (108), which can convert AC to DC power and vice-versa, is connected to the motor/generator (104). These components are then linked to a control processor (112) that can control the power output of the system.

A connector circuit combines each of the systems.  In a Beacon Smart Energy Matrix, 10 flywheels are connected.

The ‘804 Patent relates to methods for regulating the AC frequency of the electrical power to be supplied by the flywheels to the grid.

By tracking long-term variations in the power being utilized by the grid, it can then be determined when it would be best to have the flywheels in either power-generating or power-absorbing mode.  Thus, if the grid is in need of more energy, the flywheels can shift into power-generating mode.

Rosemary Ostfeld is a contributor to Green Patent Blog.  Rosemary recently completed both her undergraduate and graduate education at Wesleyan University in Middletown, Connecticut.  She double majored in Biology, and Earth & Environmental Sciences as an undergraduate, and received her Master’s in Earth & Environmental Sciences.

Too Mod for Batteries: Ioxus Introduces iMOD Ultracaps

November 23rd, 2011

Ioxus is a manufacturer of premium performance ultracapacitor technology for transportation, alternative energy, medical, industrial and consumer markets.  Ioxus has focused on improving capacitor technology, specializing in electric double layer capacitors (EDLC).

The Oneonta, New York, company recently announced the release of its 16V/58F iMOD Ultracapacitor Module Series for alternative energy markets (pictured below).

The iMOD is an ultracapacitor comprising a plurality of in-line high voltage capacitors which provide power for such green technologies as wind turbine pitch control systems, start and drive systems on hybrid vehicles, and power conditioning for renewable energy systems.  The iMOD allows for in-line high voltage capacitors sized to parallel or replace common battery sizes.

According to Cleantech PatentEdge™, Ioxus currently owns one U.S. utility patent and has at least four pending U.S. patent applications, all relating to ultracapacitor technology.

U.S. Patent Application Publication No. 2010/0053844 (‘844 Application) is entitled “High voltage EDLC cell and method for the manufacture thereof” and directed to an EDLC having a unit cell structure with alternately interleaved electrodes formed lithographically and a separator between the electrodes and impregnating an electrolyte therein.  The ‘844 Application also describes a manufacturing process for the EDLC cells.

U.S. Patent No. 7,830,646, is entitled “Multi electrode series connected arrangement supercapacitor” and directed to an EDLC series stack formed into a single electrolyte cell structure.  The figure below shows a complete 12-volt EDLC in a poly bag package. 

An EDLC device (10) includes five concatenated electrode assemblies (34-38).  Voltage monitor/control tabs (39-42) extend external to poly bag (31), which provides a lightweight, puncture resistant, air-tight seal for the cell stack.  The power tabs (32, 33) and voltage monitor/control tabs (39-42) provide the complete electrical interface.

Ioxus ultracapacitors have many applications in green technology. For example, they have previously been used on wind turbines to control the pitch of rotor blades relative to wind speed in order to maximize efficiency. Rotor blade pitch control is also used as a safety feature to slow or stop the turbine when wind speeds are too high or in the event the turbine loses connection to the grid.

Compared to batteries, ultracapacitors are preferred for use in wind turbines due to their light weight, solid state design, and ability to operate in cold conditions. Ultracapacitors also require very little maintenance and have an approximate ten-year life span – twice as long as most batteries.

According to Ioxus’ press release, the iMOD modules deliver easy to install, ready to use, and durable ultracapacitor modules at a lower price and with improved cell balancing.

According to Chad Hall, Ioxus Founder and Vice-President of Sales, “This is a complete, ready to install package. You can go up to 750V without any external management, you can run parallel to a 12V battery or replace a 12V battery. It’s ruggedized to handle insustrial environments.”

While ultracapacitors charge quickly, they are limited in application as they also discharge quickly. They are ideal when relatively short bursts of electricity are needed. As this technology improves, its application will undoubtedly increase.

Are ultracapacitors the new battery? Due to their lack of long term power delivery, ultracapacitors are not ready to replace batteries yet, however, they are certainly preferred in some situations.

David Gibbs is a contributor to Green Patent Blog.  David is currently in his third and final year at Thomas Jefferson School of Law in San Diego.  He received his undergraduate degree in Geology from the University of California, Berkeley.