In Situ Engineering of Core-shell Ag@Cu Structure on Porous Nanowire Arrays for High-Energy and Stable Aqueous Ag-Bi battery.

To achieve practical aqueous rechargeable battery with high energy density and long cycle life, state-of-the art of cathode material with low-toxic and environment-friendly is urgent. 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 on situ Cu porous nanowire arrays skeleton (Ag@Cu NWAs) is designed as the efficient cathode of an aqueous rechargeable battery. Benefiting from the ultrathin metal Ag shell (~7 nm) and the high-conductivity metal Cu core, along with the robust porous nanowires framework, the as-obtained Ag@Cu NWAs cathode integrates the features of maximal utilization of active material, superior charge transfer and exceptional electrolyte accessibility, exhibiting a considerable capacity of 1.79 mAh cm (458 mAh g: 92.3% of theoretical capacity) as well as remarkable cyclic stability (83.6% retention after 5000 cycles). Furthermore, a well-designed aqueous rechargeable Ag//Bi full cell is fabricated using the Ag@Cu NWAs cathode, achieving high capacity (1.57 mAh cm at 2 mA cm) with excellent rate performance (92.9% at 20 mA cm), and admirable energy density of 16.96 mWh cm. This work provides a promising strategy to construct rationally new types aqueous rechargeable batteries materials based on multi-metal nanocomposites, holding great potential for practical electronic devices.