A scheme of the battery.
Image: CNR - Politecnico di Milano
An Australian-Italian research group has designed a prototype of a quantum battery that could be used for applications based on superextensive charging.
Quantum batteries are storage devices that work on Quantum Mechanics principles and reportedly have a faster charging time due to the quantum entanglement among the units. These devices are able to harvest and store light energy simultaneously and are intended for applications on the nanoscale. “Quantum batteries have a counter-intuitive property in which the recharge time is inversely related to the battery capacity, that is the amount of stored electrical charge,” said Cnr-Ifn researcher, Tersilia Virgili. “This leads to the intriguing idea that the charging power of quantum batteries is super-extensive, meaning that it increases faster with battery size.”
The prototype consists of a microcavity enclosing a molecular dye known as Lumogen-F orange (LFO). “The structures fabricated consist of a thin (active) layer of a low-mass molecular semiconductor dispersed into a polymer matrix that is deposited by spin coating and positioned between two dielectric mirrors, forming a microcavity,” the scientists explained. “By diluting the LFO, we reduce intermolecular interactions that lead to emission quenching, producing a high photoluminescence quantum yield of around 60% at low concentration.”
The Italian group prepared samples with 0.5, 1, 5, and 10% concentrations, which are described as representative of the optimal operating regimes. The device's charging and energy storage dynamics were assessed via ultrafast transient-absorption spectroscopy. “Our results demonstrate that as the number of molecules in the microcavity increases, its charging power density remarkably increases”, the academics said commenting on the testing results. “This means that it takes less time to charge a single microcavity containing N molecules than it would to charge N single-molecule microcavities, even if the latter were charged simultaneously.”