In view of the cross-country hydrogen vehicle tour last week, it seems like a good time for a post on hydrogen technology.  Global Hydrogen, Inc. (GHI) is a small Texas company founded by Dr. Linnard Griffin that says it has developed a more efficient, low-voltage hydrogen production process. (see the Matter Network story)

Dr. Griffin is the named inventor on a family of patent applications covering his hydrogen generation equipment and techniques.  U.S. Application Pub. Nos. 2005/0042150 (’150 application) and 2006/0180464 (’464 application) are directed to apparatus and methods for producing hydrogen.

Known reactions for producing hydrogen gas from water and metallic compounds either react too quickly or too slowly to be useful or require very expensive metals of intermediate reactivity.  According to the ’150 and ’464 applications, Dr. Griffin’s process makes hydrogen efficiently with relatively inexpensive metals.

The process generates hydrogen from water using a special electrolyte.  The reaction uses metal catalysts in colloidal form (i.e., composed of very small particles that are dispersed, but not dissolved, in solution).  The tiny size of the catalyst particles results in a large effective surface area that increases contact with other molecules and accelerates the rate of reaction.

The ’150 and ’464 applications describe the electrolyte reaction medium and the electrode construction of the reaction vessel (pictured below).  The medium comprises water, an acid or base, two colloidal metal catalysts and an ionic salt. 

The reaction occurs in a reaction vessel 100 which has an anode 106 (an electrode that attracts negatively charged ions) and a cathode 104 (an electrode that attracts positively charged ions), each in contact with the reaction medium 102.  The anode and cathode are connected to a controller 108, which allows the user to select from a range of hydrogen production rates. 

The reaction vessel has an inlet 112 for adding water and an outlet 110 for the hydrogen to escape.  The resulting hydrogen can be fed to a fuel cell to produce electric energy.

According to GHI’s web site and its white paper on the technology, this process requires substantially less electricty than the best hydrogen generation technique currently known (41.2 kilowatt hours per kg of hydrogen produced versus 53.4 kWh per kg). 

The other obvious advantage of Dr. Griffin’s technology is that it could make hydrogen production from water economical.  It would be a big step forward if clean hydrogen production becomes commercially viable – currently the raw materials for most industrial hydrogen generation are fossil fuels.

In a recent post, I wrote about one of A123 Systems’ (A123) new products - the Hymotion Plug-in Conversion Module, which can convert the Toyota Prius into a plug-in electric vehicle and boost its mpg to over 100 for the first 30-40 miles of driving.

Last month saw more good news for the Boston area battery maker.  First, the U.S. Department of Energy’s National Renewable Energy Laboratory (NREL) announced that it had signed a three-year deal with A123 to support the company’s efforts to develop more powerful and longer lasting batteries for hybrid-electric vehicles.

Under the Cooperative Research and Development Agreement, NREL and A123 will research new techniques for improving thermal management in transportation batteries.

A123 also got a boost for a different application of its battery technology – using batteries to get more power out of the electric grid.  CNET recently reported that some electric utilities (unnamed for now) have made a deal with A123 to use its lithium ion batteries to help stabilize the grid (see the greentech media story).

Several of A123′s patents and applications, including U.S. Patent No. 7,348,101, U.S. Patent No. 7,261,979 and U.S. Application Pub. No. 2007/0166617, cover various aspects of lithium ion battery technology.   A123′s patented battery technology reduces the amount of time necessary for charging and loses relatively little capacity and power over numerous charge/discharge cycles. 

The continuing good news for A123 indicates that the company is widely viewed as a winner.  Significantly for A123, it also demonstrates the versatility of its technology for use in a variety of applications.

Battery maker A123 Systems (A123) just started selling its L5 Hymotion Plug-in Conversion Modules, which can transform the Toyota Prius into a plug-in vehicle capable of getting up to 100 mpg for the first 30-40 miles of driving.  The L5′s high energy capacity lithium ion batteries supplement the vehicle’s battery and allow the Prius to use its electric drive more often and for longer distances.  More frequent periods of all electric driving translate into better fuel efficiency. (read the Ecogeek piece and green tech gazette article on the L5)

A123 calls the Hymotion technology Nanophosphate, which means the batteries use lithium iron phosphate as cathode material.  Several of A123′s patents and applications cover lithium iron phosphate batteries, including U.S. Patent No. 7,348,101, U.S. Patent No. 7,261,979 and U.S. Application Pub. No. 2007/0166617. 

A123′s patented battery technology reduces the amount of time necessary for charging and loses relatively little capacity and power over numerous charge/discharge cycles, an important advantage for applications that need high power for long periods of time, such as motor vehicles.  Specifically, one problem with rechargeable batteries is that relatively high charge rates (i.e., less than half an hour) typically cause growth in impedance (resistance and voltage drop). 

Impedance can lead to lithium plating, a film formation on the surface of the negative electrode materials which consumes some of the active lithium from the battery and results in a loss of capacity.  The materials used by A123, including lithium iron phosphate, achieve low impedance growth.  The resulting batteries don’t have the problem of lithium plating and therefore maintain higher power capacities over time, enabling the highly efficient Prius to be even more efficient.