  Quantum coherences, correlations and collective effects can be harnessed to
the advantage of quantum batteries. Here, we introduce a feasible structure
engineering scheme that is applicable to spin-based open quantum batteries. Our
scheme, which builds solely upon a modulation of spin energy gaps, allows
engineered quantum batteries to exploit spin-spin correlations for mitigating
environment-induced aging. As a result of this advantage, an engineered quantum
battery can preserve relatively more energy as compared with its non-engineered
counterpart over the course of the storage phase. Particularly, the excess in
stored energy is independent of system size. This implies a scale-invariant
passive protection strategy, which we demonstrate on an engineered quantum
battery with staggered spin energy gaps. Our findings establish structure
engineering as a useful route for advancing quantum batteries, and bring new
perspectives on efficient quantum battery designs.
