A printed paper-based Zn-air/Ag hybrid battery with switchable working modes

Paper-based battery is a low-cost, lightweight, flexible and environmentally-friendly technology for small-power and flexible electronics, which can be conveniently fabricated by printing. In this work, we propose an innovative paper-based hybrid battery using Zn foil as anode and Ag grid-supported oxygen catalyst as cathode. Benefited from its composite cathode, this hybrid battery can work in both primary Zn-air mode and secondary Zn-Ag mode in different mission profiles. When working as a primary battery, the Zn anode is oxidized and the ambient air is reduced by the oxygen catalyst inside cathode, producing an OCV of 1.5 V and a peak power density of 17.8 mW cm(-2). When working as a secondary battery, the Zn anode is reduced and oxidized periodically while the Ag grid inside cathode is oxidized and reduced accordingly. The charge and discharge voltage plateaus are closely around 1.6 V, leading to an excellent energy efficiency of 95.2%. Moreover, this hybrid battery can switch its working modes smoothly without performance loss, and the battery flexibility is proved to be high in both working modes. In summary, this paper-based Zn-air/Ag hybrid battery is especially suitable for powering flexible electronics in both long-term discharge missions and multi-cycle rechargeable tasks. (C) 2021 Elsevier Ltd. All rights reserved.