There is an urgent need to design practical aqueous rechargeable batteries (ARBs) with high energy density and long cycle life, using state-of-the-art cathode materials with low toxicity and environmental friendly nature. In virtue of the stable discharge potential and high energy density, silver (Ag) presents a huge perspective in the field of aqueous batteries. Herein, the paradigm of a novel core-shell Ag@Cu structure in situ Cu porous nanowire array skeleton (Ag@Cu NWA) is designed as the efficient cathode of an ARB. Benefiting from the ult...