New Paperlike Battery Can Withstand Extreme Cold
Say you want to fly a drone up to 100,000 feet. You're gonna have a problem: The battery in your UAV is probably gonna run out of juice real fast at the extremely low temperatures found in the upper reaches of our atmosphere. Try to send a drone into low Earth orbit and it gets even worse.
Batteries run on chemical reactions, and lower temperatures make those reactions slower. But a battery developed by a Kansas State University engineer works through this problem with a radical new design.
Gurpreet Singh and his team have designed a paper-like battery using materials that aren't traditionally used in batteries or electrodes, namely graphene and silicon. It's tough to get them into traditional batteries because of problems like chemical-mechanical instability and poor cycling efficiency (the number of complete charge-discharge cycles a battery can perform before it falls below 80 percent of peak performance).
Singh and his team crafted an electrode that places a ceramic called silicon oxycarbide between platelets of chemically modified graphene. This ceramic is created by heating a liquid resin to the point where it decomposes and transforms into sharp glass-like particles. The result looks like paper. What's crucial about this design is what it doesn't use-traditional metal and polymer. Singh saw those elements as dead weight, so he cut them. "[The] paperlike design is markedly different from the electrodes used in present-day batteries because it eliminates the metal foil support and polymeric glue-both of which do not contribute toward capacity of the battery."
With the elimination of these inactive elements, Singh has created a battery that is lighter and more efficient. It has a near 100 percent cycle efficiency for more than a thousand discharges. While this is important, the really exciting stuff happens when the materials get cold.
An Energizer Lithium AA battery starts to lose its miliampere-hour (mAh) capacity as the temperature drops below 0 degrees Celsius, and as the temperature drops, the capacity loss increases. In Natural Communications, Singh notes that the paper electrode cells function at 200 (mAh) properly even when kept at -15 degrees (about 5 degrees Fahrenheit) for a month.
The possibilities with a battery that can better withstand the cold are exciting. There's the idea of small, rechargeable drone that can fly high into the atmosphere, carrying a camera being used for observational research in polar environments or deep underwater. Singh notes that this could eventually allow for practical battery usage in space. The next step is make everything bigger: KSU's press release notes that Singh and his team are looking at making their unique "electrode material at even larger dimensions."
Source: Phys.org
