Your knees and smartphone’s battery have surprisingly similar needs, a University of Michigan professor discovered, and this has led to a as structural battery unuz prototype that contains a cartilage-like material for high durability of the batteries.
The idea behind the structural batteries is to store energy in structural components, such as the bumper of a structural drone or a bumper of an electric vehicle. Researchers became a long-term target for the industry because they could reduce their weight and extend their range. However, structural batteries have so far been heavy, short-lived or unsafe.
In a study published in ACS Nano, researchers describe how they make a battery-resistant, rechargeable zinc battery with a solid electrolyte like cartilage. They showed that batteries could change the upper case of a few commercial aircraft. Prototype cells can operate at more than 100 cycles of 90 percent capacity and can withstand severe impacts and can even withstand stabbing without losing voltage or causing a fire.
“A battery that is also a structural component has to be light, strong, safe and have high capacity. Unfortunately, these requirements are often mutually exclusive,” said Nicholas Kotov, the Joseph B. and Florence V. Cejka Professor of Engineering, who led the research.
Using cartilage properties
To prevent these changes, the researchers used branched nanofibers that were similar to zinc and cartilage collagen fibers, a legitimate structural material.
Ahmet Emrehan Emre, PhD candidate in biomedical engineering, poured a manganese oxide slurry onto an aluminum foil to function as a prototype structural catheter. Credit: Evan Dougherty, Michigan Engineering
“Nature does not have zinc batteries, but it had to solve a similar problem,” Kotov said. “Cartilage turned out to be a perfect prototype for an ion-transporting material in batteries. It has amazing mechanics, and it serves us for a very long time compared to how thin it is. The same qualities are needed from solid electrolytes separating cathodes and anodes in batteries.”
It combines mechanical strength and durability with the ability to allow cartilage, water, nutrients and other materials to pass through our bodies. These qualities are almost identical to a good solid electrolyte that has to resist damaging the dendrites while allowing ions to flow from one electrode to another.
Dendrites are branches of metals that penetrate the separator between the electrodes and form a rapid strip for electrons, shorten the circuit and potentially cause fire. Zinc tended to end only after a few charge / discharge cycles because it was ignored for previously rechargeable batteries.
Only the membranes made by the Kotov team not only mix the zinc ions between the electrodes with the ferry, but also stop the piercing dendrites in the zinc. Like cartilage, membranes consist of ultra-thin nano fibers interwoven with a softer ion-friendly material.
In batteries, the aramid is composed of nano fibers (substances in the bullet-proof vest), polyethylene oxide (a chain-like, carbon-based molecule) and a zinc salt which replaces the soft cartilage components.
Showing security and benefit
The team matched the zinc electrodes with manganese oxide, a combination of standard alkaline batteries to make working cells. However, in rechargeable batteries, the cartilage-like membrane replaces the standard separator and alkaline electrolyte. As secondary batteries on the aircraft, zinc cells can extend the flight time by 5 to 25 percent depending on the size of the battery, the mass of the aircraft and the flight conditions.
Safety is very important for structural batteries, so the team intentionally stabbed the cells with a knife. Despite multiple devam wounds yakın, the battery continued to discharge near the design voltage. This is possible because there is no liquid to leak.
For now, zinc batteries are the best as secondary power sources because they cannot charge and discharge as fast as lithium-ion brothers. The Kotov team, however, is looking to investigate if there is a better common electrode that can increase the speed and life of zinc rechargeable batteries.