In a conventional battery, charged ions race in one direction across a sea of ​​other particles as the battery charges, then return in the other direction to immediately release the stored energy. The ions move back and forth, some of them getting distracted, until the battery’s capacity is exhausted and it loses energy too fast to be useful. But physicists who are good at it are inventing new ways to store energy in handy portable devices, relying on a strange time-distorting quantum phenomenon, among other unusual developments.

“Current batteries for low-power devices such as smartphones or sensors often use chemicals such as lithium to store charge, while quantum batteries use microscopic particles such as strings of atoms,” explains Yuanbo Chen, a PhD student in physics at the University of California, Berkeley. Beijing. Tokyo.

In his latest work, Chen worked with physicist Gaoyang Zhu and colleagues at the Beijing Computational Science Research Center, part of the Chinese Academy of Engineering Physics, to test the idea of ​​creating a quantum battery that enables charging of stages. simultaneously, thus increasing energy. storage and thermal efficiency.

“While chemical batteries are subject to the laws of classical physics, microscopic particles are quantum in nature, so we have a chance to discover ways to use them that disrupt, or even disrupt, our intuitive understanding of what happens at small scales,” Chen says. .

Chen, Zhu, and their colleagues are certainly not the first group to imagine how a quantum battery might work, but they tested their ideas experimentally on a laboratory bench filled with scattered lasers, lenses, and mirrors.

In 2019, a team of Canadian researchers developed a project for a quantum battery that never loses its charge. Their idea, still purely theoretical, relies on a different quantum mechanism: one that involves trapping quantum components in a “dark state” where the material cannot interact with its environment or lose energy.

Zhu and his colleagues’ approach is an extension of the quantum phenomenon known as superposition, often cited in quantum computing, in which particles exist in a flurry of possible states until they are measured. Researchers have recently shown that this overlap of probabilities also disrupts the natural order of time.

In classical physics and everyday life, events can only occur in a linear or fixed order. Consider the cause before the effect, or event A (pressing a button) before event B (turning on a light).

But in the quantum realm, this linear order is disrupted and superposition allows events to occur along two parallel paths simultaneously. This confuses time in a sense, because one event following another can also affect the outcome of the event as if it had happened before, since both orders of events (A to B and B to A) are true at the same time.

“Simply put, the laws of quantum mechanics were found to allow quantum superposition of causal orders,” Zhu and colleagues explain.

To apply this to energy storage, the researchers implemented this strange process with a quantum switch, tested several different charger configurations, and created a system that could power two chargers simultaneously.

“We showed that the way you charge a battery made of quantum particles can significantly affect the performance of the battery,” Chen says. “We saw huge benefits in both the energy stored in the system and thermal efficiency.”

“We also found a counterintuitive effect where a relatively less powerful charger ensures a battery charged with more energy and higher efficiency,” the researchers wrote in their paper.

Although this quantum “battery” looks more like a laser network on a lab bench and is still years away from any practical applications, it’s still a great demonstration of the basic principles and what might be possible in the future. It didn’t happen, it already happened in the past.