By utilizing superconducting flux qubits (FQs) embedded in a transmission line resonator cavity, we propose a scalable quantum battery (QB) and analyze its charging dynamics in the dispersive regime. The QB can be efficiently charged mediated by the cavity, which induces coherence among all FQs through a common photonic mode. Our results indicate that such coherence enhances the charging power. Furthermore, we identify a trade-off: increasing the battery size improves the charging power but reduces the storage capacity. By selecting an appropriate battery size, we achieve a practical QB that combines high power with large capacity. This optimal size can be moderately increased at the cost of a weaker coupling strength between the FQs and the cavity. This work, which integrates superconducting quantum circuits with energy storage technology, may pave the way for scalable and reliable quantum applications.
Shi et al. (Wed,) studied this question.