A thin-film coating process for manufacturing thermal batteries could lead to create lighter batteries for future applications.
A thin-film coating process for manufacturing thermal
batteries used in nuclear weapons and other munitions - invented at Sandia
National Laboratories - will be industrialized under a new corporate
partnership with a Maryland company. The process could lead to create lighter
batteries for future applications.
A thermal battery is a nonrechargeable, single-use energy
source that can remain inert for years at room temperature before becoming
activated at temperatures as high as 1,100°F (~600°C). The thin-film coating
process changes the way some thermal batteries have been made since the 1950s.
Sandia and ATB Inc., a Cockeysville, Md.-based manufacturer
of thermal batteries, signed a cooperative research and development agreement
to test the thin-film coating process for large-scale industrial production.
Sandia researchers also are looking into whether a patented
binder used in the thin-film coating process has commercial applications. For
example, researchers plan to explore whether the coating can be used in
lithium-ion batteries in electric and hybrid vehicles, and in batteries used in
the petroleum industry when drilling deep underground in hot geothermal
Sandia researcher Frank Delnick led the effort to make the
thermal battery components as thin-film coatings instead of pellets. The
process will work best for thermal batteries that are active for a fraction of
a second to a few minutes, he said. On average, thermal batteries made with
thin-film coatings would use one-fifth to one-half the materials needed in
their conventionally manufactured counterparts, Delnick said.
The new process also could allow manufacturers to produce
different shapes of thermal batteries, Delnick said. Current thermal batteries
are cylindrical and range in size from a man’s thumb to a one-pound coffee can.
The first thermal battery made using the new process was slightly thicker than
a postage stamp and about the size of a quarter, he said.
Sandia’s process uses relatively inexpensive equipment
common in the paint industry that coats the battery components as thin films
onto stainless steel foil. The coatings are held together and bonded to the
foil using a patented binder. The binder must withstand temperatures of 660 to 1,100°F
(~350 to 600°C), which are required to melt the salt electrolyte and activate
the battery. Once activated, the binder must remain chemically and mechanically
stable throughout the discharge of the battery without emitting gas or
producing other side reactions that could adversely affect the performance of
the battery, he said.
The coated materials in the batteries are much tougher than
those in current models. Delnick expects that thin-film thermal batteries will
perform much better in high-shock environments and will be much more amenable
to automated manufacturing.
Thermal Battery Manufacturing Method to be Commercialized
July 5, 2011