Scientists have developed a new type of battery that runs using moisture from the air instead of the liquid chemicals found in most batteries.
The lightweight, flexible battery could one day power wearable health devices, smart sensors, and other small electronics while being safer for people and the environment.
The new battery was created by researchers at North Carolina State University and Rice University.
Their study was published in the journal Science Advances.
Many modern electronic devices, such as wearable fitness trackers, medical monitors, and Internet of Things (IoT) sensors, need small, lightweight power sources.
Traditional lithium-ion batteries often work well, but they can be heavy, rigid, and contain flammable or toxic materials that may leak if damaged.
The new moisture-activated battery offers a different solution.
Instead of using a liquid electrolyte stored inside the battery, it absorbs water from the surrounding air. The water dissolves special lithium chloride salts inside the battery, creating a saltwater electrolyte that allows electricity to flow.
Because the battery only starts working after it is exposed to air, it can remain inactive while sealed in its package. This gives it a much longer shelf life than many traditional batteries.
The battery also uses environmentally friendly materials. It contains a magnesium anode, a silver-based cathode, and a cellulose membrane made from plant material.
Since it mainly operates using salt water instead of flammable chemicals, researchers say it is safer and less harmful to the environment than many existing battery technologies.
The team also solved a common problem with flexible batteries. Stretchable batteries often lose performance when pulled because gaps form between their parts.
To overcome this, the researchers copied the design of pangolin scales. Pangolins are mammals covered with overlapping protective scales. By arranging the battery’s parts in a similar overlapping pattern, the battery continues to work well even when bent, twisted, or stretched.
To test the design, the researchers used the battery to power a wireless Bluetooth blood oxygen monitor for up to 30 hours. This is similar to the operating time of many conventional batteries, showing that the new technology is practical for real-world use.
The researchers believe the battery could be useful in many future products, including wearable medical devices, smart clothing, environmental sensors, miniature robots, and other connected electronics.
One unusual feature of the battery is an optional built-in “kill switch.” This security feature is designed for situations where sensitive electronic devices need to be destroyed if someone tries to tamper with them.
The kill switch contains a dry mixture of aluminum and iodine powder stored in a separate compartment. If someone attempts to remove or open the device, the powders come into contact with moisture collected by the battery. This triggers a rapid chemical reaction that generates enough heat to destroy the device within minutes.
In laboratory tests, researchers installed the kill switch inside a wireless gas sensor. Once activated, the sensor and its electronic components were completely destroyed in less than three minutes.
While the self-destruct feature is mainly intended for specialized security or intelligence applications, the researchers say the biggest achievement is the battery itself.
By combining flexibility, safety, biodegradability, and reliable performance, this new technology could help power the next generation of smart electronic devices while reducing environmental impact.
