Noise is not always detrimental: the capacity of quantum batteries is enhanced in black holes

Quantum battery capacity, as a critical metric for quantifying energy storage and release in quantum systems, exhibits complex behaviors in curved spacetime and noisy environments. This study focuses on bipartite mixed state, aiming to explore the modulation of quantum battery capacity by Hawking radiation and environmental noise. We find a counterintuitive phenomenon that Hawking radiation can enhance battery capacity, exerting a positive influence on energy storage, a result that stands in stark contrast to the detrimental effects typically associated with entanglement and coherence. When a quantum battery is simultaneously subjected to environmental noise and Hawking radiation, its capacity generally degrades, with the extent of degradation depending on the type of noise. The charging and discharging behaviors largely follow the same patterns observed in the noiseless scenario; however, under a bit flip channel with strong noise intensity, the charging-discharging pattern reverses. In the extreme case of maximum noise intensity, the capacity of the quantum battery under depolarizing noise tends to zero. The underlying physical mechanism lies in the fact that the bit flip channel disrupts the original population distribution of energy levels, thereby altering the average energy of the system and establishing a perturbative environment for bidirectional energy exchange. This differs fundamentally from the phase flip channel. These findings offer a new perspective for the theory of quantum batteries in noninertial reference frames.