Kamal Ghorui
The CSIRO, RMIT and the University of Melbourne have successfully built a quantum battery prototype from theory into practice, meaning both energy and physics sciences have now made this transition to energy technology. Whereas traditional electrochemical cells rely on chemical reactions for their energy storage, this organic battery uses principles of quantum mechanics, specifically superposition and light-matter interactions, for the same purpose. Superextensive charging (when a battery can charge faster as it increases in size) is one of the key characteristics that define this development; therefore, the quantum battery will, in turn, overcome the degradation factor typically seen in conventional batteries as they increase in size. This room temperature prototype will potentially allow near-instantaneous charging and long-distance wireless power transfer using lasers.
Quantum battery that charges using light
Research published at Nature showed that a proof-of-concept device was developed using a multi-layered organic semiconductor for wireless charging through laser energy. The researchers were able to use a microcavity to trap photons and create conditions under which it charged its battery using quantum ‘co-operative’ effects. As such, this type of battery could charge much faster than traditional chemical batteries because it does not have to rely upon the physical limitation of ion movement.
Beyond linear limits: The end of the battery charging bottleneck
Through this study, the researchers also made a pivotal finding: without the limitations imposed by classical physics, there are no linear rules governing the rate at which quantum batteries can be charged. In traditional systems, as additional cells are added to the system’s total capacity, they typically slow the rate at which they charge and thus complicate the process of charging. In their prototype quantum battery, due to the ‘co-operative’ nature of the molecules, adding additional qubits enables all qubits to collectively work together to improve the energy absorption rate of qubits, a behaviour labelled as ‘superabsorption’.
How organic materials tamed the quantum state
Historically, many quantum experiments that needed to be maintained at subzero temperatures to preserve the quantum state could now take place at room temperature, thanks to the discovery of the potential for organic materials. The researchers have also used a distributed Bragg reflector (a form of high reflection mirror) to facilitate light-matter interaction so that the energy remains stored but has little chance of immediately becoming incoherent.
How quantum batteries will power the next generation of EVs
According to the CSIRO, this research project ultimately has the goal of horizontally scaling the technology to the consumer level, i.e., to use the technology to power electric vehicles (EVs). This means that, in addition to charging the battery with electricity through electromagnetic radiation (light/lasers), there is the potential for what the researchers call over-the-air charging. This type of charging will allow for powering electric vehicles and handheld devices from a distance, without ever needing to be plugged into the grid, etc.
