Quantum batteries can theoretically charge faster and store more energy than conventional batteries—except they tend to lose all of their stored energy in nanoseconds. Now scientists have developed a new prototype quantum battery that can hold onto its energy for 1,000 times as long as previous devices. They hope that the breakthrough will someday lead to quantum batteries that could power portable electronics and small sensors.
Quantum physics can often make matter act in surprising ways. Superradiance is a phenomenon in which a group of energetic atoms releases a far more intense pulse of light than they could individually. The reverse of superradiance is also possible—superabsorption, in which atoms cooperate to absorb light better.
Recently, scientists have started developing quantum battery prototypes that can take advantage of such quantum effects. For instance, a 2022 study unveiled a superabsorbent device that collects energy more quickly the bigger it gets. However, previous quantum battery prototypes lost energy nearly as quickly as they charged, because the superabsorption in these devices was also coupled with superradiance, leading to extremely fast discharge rates.
Extending Quantum Battery Lifespan
In a new study, Francesco Campaioli, a vice chancellor’s research fellow at the Royal Melbourne Institute of Technology in Australia, and his colleagues sought to prolong the life of quantum batteries by experimenting with triplet states, the state of electrons in a molecule after they absorb light. The researchers focused on dark triplet states, which are bad at emitting and absorbing light. This means they can store energy longer than their bright counterparts.
At the core of the new device are two different layers of material. One layer, which contains the dye Rhodamine 6G, absorbs light very well. It transfers absorbed energy to a layer made of a compound called palladium tetraphenylporphyrin, which stores this energy as dark triplet states. These layers are separated by an inert polymer spacer to help steer their interactions and sandwiched between reflective silver layers that help control how light from a green 514-nanometer laser energizes the device.
“Thanks to the dark triplets in the storage layer, the energy stays in the device for roughly 1,000 times longer than it enters the device,” Campaioli says.
The improvement might seem minor—the new prototype can store energy for microseconds instead of nanoseconds. Still, “that’s not bad comparatively,” Campaioli says. “It’s the equivalent of having a phone that charges in 30 minutes and runs out of battery after about 20 days if left idle. Not too shabby.”
The scientists are collaborating with industry partners to design the next iteration of prototypes. “There is still a lot of work to do to develop these ideas into a technology that could impact everyday life,” Campaioli says. “What matters to me is that we have a clear understanding of the challenges that we need to overcome to make it happen.”
The scientists detailed their findings on 23 June in the journal PRX Energy.
- Quantum Sensors Could Quell EV Range Anxiety ›
- How Quantum Computers Can Make Batteries Better ›
- These Superabsorbent Batteries Charge Faster the Larger They Get ›
Charles Q. Choi is a science reporter who contributes regularly to IEEE Spectrum. He has written for Scientific American, The New York Times, Wired, and Science, among others.
