Superabsorption Progress Towards Quantum Batteries

University of Adelaide and their overseas partners have successfully proved the concept of superabsorption, a crucial idea underpinning quantum batteries.

Quantum batteries offer the potential for vastly better thermodynamic efficiency, and ultra-fast charging time, much faster and more efficient than the electrochemical batteries like Nickel Metal Hydride or Lithium Ion, in common use today. By expanding earlier theoretical research into individual, isolated quantum batteries to consider a more realistic, many-body system with intrinsic interactions, the researchers have shown that interacting many-body quantum batteries do charge faster than their non-interacting counterparts.

The bigger the number of quantum batteries, the less time they need to charge. If one quantum battery charge takes an hour, two batteries would take 30 minutes. Increasing the number of quantum batteries to 10,000 and they would pretty much charge instantaneously.

To prove the concept of superabsorption, they built several wafer-like microcavities of different sizes which contained different numbers of organic molecules. Each was charged using a laser.

The idea of the quantum battery has the potential to significantly impact energy capture and storage in renewable energy and in miniature electronic devices.

Science Advances – Superabsorption in an organic microcavity: Toward a quantum battery

The rate at which matter emits or absorbs light can be modified by its environment, as markedly exemplified by the widely studied phenomenon of superradiance. The reverse process, superabsorption, is harder to demonstrate because of the challenges of probing ultrafast processes and has only been seen for small numbers of atoms. Its central idea—superextensive scaling of absorption, meaning larger systems absorb faster—is also the key idea underpinning quantum batteries. Here, we implement experimentally a paradigmatic model of a quantum battery, constructed of a microcavity enclosing a molecular dye. Ultrafast optical spectroscopy allows us to observe charging dynamics at femtosecond resolution to demonstrate superextensive charging rates and storage capacity, in agreement with our theoretical modeling. We find that decoherence plays an important role in stabilizing energy storage. Our work opens future opportunities for harnessing collective effects in light-matter coupling for nanoscale energy capture, storage, and transport technologies.

Other Quantum Battery Research

Arxiv – Quantum batteries at the verge of a phase transition

Starting from the observation that the reduced state of a system strongly coupled to a bath is, in general, an athermal state, we introduce and study a cyclic battery-charger quantum device that is in thermal equilibrium, or in a ground state, during the charge storing stage. The cycle has four stages: the equilibrium storage stage is interrupted by disconnecting the battery from the charger, then work is extracted from the battery, and then the battery is reconnected with the charger; finally, the system is brought back to equilibrium. At no point during the cycle are the battery-charger correlations artificially erased. We study the case where the battery and charger together comprise a spin-1/2 Ising chain, and show that the main figures of merit – the extracted energy and the thermodynamic efficiency – can be enhanced by operating the cycle close to the quantum phase transition point. When the battery is just a single spin, we find that the output work and efficiency show a scaling behavior at criticality and derive the corresponding critical exponents. Due to always present correlations between the battery and the charger, operations that are equivalent from the perspective of the battery can entail different energetic costs for switching the battery-charger coupling. This happens only when the coupling term does not commute with the battery’s bare Hamiltonian, and we use this purely quantum leverage to further optimize the performance of the device.

SOURCES- University of Adelaide, Science Advances, Arxiv
Written By Brian Wang,

13 thoughts on “Superabsorption Progress Towards Quantum Batteries”

  1. Correct,
    But what exactly does “fast charging” imply?
    Like you’re at a gas station, where you fully charge in 10-15 minutes with a bio-break?

  2. If you are charging overnight at home this is definitely "fast enough". Also, most likely your not using up 450 mile range a 100kw pack going to work every day.

  3. Nah, a 'battery' that stored and released light could be supremely practical, if affordable. Imagine, for instance, a skylight that stored part of the light passing through it, and released it on command. Or a camping light you just left laying out in the sun, and at night that light shines back out of it.

  4. It's more like a capacitor than a battery. You charge it with light, and discharge it as you wish.
    It's also could become solar PV with built in storage, if really cheap.

  5. Yea, particularly considering that the input into the battery is light, not electricity… Is the output also light, pray tell? That would make it supremely impractical…

  6. Brian,
    We continue to see and hear the terms “fast charging”.

    Consider the case of a 100kwh Tesla battery pack:

    Most people will be charging their vehicles in their homes where they will, at most, have access to 240 volts @ 50 amps
    or 12,000 watts (12 kw). 
    To fully charge a 100 kWh battery pack will take over 9 hours. 
    Under the most lenient interpretation, this is not “fast”.

    The physical battery and the 
    on-board electronics play a part in this speed but are meaningless if available power is limited to 240/50/60 current.

    “Fast charging” is going to be limited to buildings with medium voltage capability which is going to be large industrial/commercial and purpose built EV charging facilities.

    I have yet to see an article on “Fast Charging” that specifies the required electrical pressure, (voltage), and current.

  7. I need to read into more about what these types of batteries would be made of. I may have issed it skimming since I'm at work, but this looks promising. But, as has already been pointed out, it's likely a long time from practical applications unless they're just incredibly easy to manufacture with very few resources.

  8. "Instantaneously", providing there is the required amount of energy that will be stored, with some losses and that the battery doesn't get destroyed by it. Quantum weirdness doesn't need any more mystifying descriptions.

    If there is less energy than that (namely, realistic power sources), then it will still take some time to charge them, maybe less than current ones, but not instantaneous.

    What seems as a very promising thing indeed, is the possibility of having several times over the energy/weight density than Li or similar ones.

  9. There have been analysis of a different type of quantum battery, that uses quantum effects in a vacuum capacitor to suppress discharge, that said 2-10 times the theoretical capacity of lithium batteries.

    But that was a completely different approach.

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