"Flexible Battery": Military Use?

Recently, the DoD announced a contest to design a portable, lighter battery pack for soldiers' equipment in the field.

The Department of Defense is asking a person or team to come up with a way to lessen the weight of the 20-40 pounds of batteries a solider carries on a typical four-day mission. The batteries power everything from soldiers' GPS systems to their night-vision goggles.

"In many missions the batteries are heavier than the ammunition they are carrying," said Dr. William S. Rees Jr., Deputy Undersecretary of Defense for Laboratories and Basic Sciences -- whose office, the Director of Defense Research and Engineering, is sponsoring the prize competition. "We'd like to reverse that ratio."

There was a million dollar prize for the design.

There is no indication that this group was working towards the prize, but I found this announced invention interesting and began thinking about how it could be integrated and adapted for military use:

Researchers develop bendable battery

WASHINGTON - It's a battery that looks like a piece of paper and can be bent or twisted, trimmed with scissors or molded into any shape needed. While the battery is only a prototype a few inches square right now, the researchers at Rensselaer Polytechnic Institute who developed it have high hopes for it in electronics and other fields that need smaller, lighter power sources.[snip]

Unlike other batteries, Linhardt explained, it is an integrated device, not a combination of pieces.

The battery uses paper infused with an electrolyte and carbon nanotubes that are embedded in the paper. The carbon nanotubes form the electrodes, the paper is the separator and the electrolyte allows the current to flow.[snip]

And over about 18 months, the groups developed the projects, into a battery, a capacitor, which stores electricity and a combination of the two.

Ajayan sees potential uses in combination with solar cells, perhaps layers of the paper batteries that could store the electricity generated until it is needed, he said in a telephone interview.

Perhaps it could be scaled up and shaped into something like a car door, offering moving electrical storage and power when needed.

It's thin. It's light. It can bend. The applications would be endless. The adaptability would be as well. One way that it could be shaped or developed for carrying could be to line already existing equipment or carrying devices with the material such as Body Armor vests, back packs, helmets, lining the cases of the equipment itself, etc, etc, etc,
In fact, if it could be integrated into the equipment itself, the equipment could be redesigned to be less bulky, creating a slimmer silhouette that would facilitate maneuverability.

Inside additional equipment or even clothing, the batteries could provide endless back up supply that was equally light. It could be carried by every member of the unit in those configurations. It could also be rolled into tubes and simply carried in a pack.

There are a few draw backs. The first is cost. Carbon nanotubes are not inexpensive to make. The technology and manufacturing capabilities could be an expensive undertaking. Although, if it is underwritten by government grants as well as has confirmed contracts, the set up costs could be offset considerably.

The second issue will be its capability to support the amount of energy required for some of the technology. The inventors believe that the battery is comparable to others already in use:

"So from the commercial standpoint, this would be very expensive if you want to make a large sheet out of this material," he said via e-mail. In addition, he said, "It does not look like it performs better than currently available batteries and supercapacitors in the market."

Actually, it could be a cost saver if the overall design of equipment, like radios, could be adapted to require less space and, thus, less material to cover, for the battery. This cost savings could translate into making the cost of the "paper" battery more inviting as well as the possibility that it would take less space to carry extras, for shipping, etc. There is a built in cost savings there. Finally, the most important savings, weight, translates into saving transport space and maneuverability for soldiers. That can translate into a more effective force and that equals winning more quickly and saving more soldiers' lives.

So, cost maybe less of a factor.

One other question that cannot be answered by this article: what sort of electrolytes are being used? If this flexible battery were integrated into equipment and armor and it was struck by a round, would it be harmful to the soldier?

If not, I think the million dollar prize can go to this group.