Atomically Thin Mesoporous Co₃O₄ Layers Strongly Coupled with N‐rGO Nanosheets as High‐Performance Bifunctional Catalysts for 1D Knittable Zinc–Air Batteries

Abstract

Under development for next-generation wearable electronics are flexible, knittable, and wearable energy-storage devices with high energy density that can be integrated into textiles. Herein, knittable fiber-shaped zinc-air batteries with high volumetric energy density (36.1 mWh cm ) are fabricated via a facile and continuous method with low-cost materials. Furthermore, a high-yield method is developed to prepare the key component of the fiber-shaped zinc-air battery, i.e., a bifunctional catalyst composed of atomically thin layer-by-layer mesoporous Co O /nitrogen-doped reduced graphene oxide (N-rGO) nanosheets. Benefiting from the high surface area, mesoporous structure, and strong synergetic effect between the Co O and N-rGO nanosheets, the bifunctional catalyst exhibits high activity and superior durability for oxygen reduction and evolution reactions. Compared to a fiber-shaped zinc-air battery using state-of-the-art Pt/C + RuO catalysts, the battery based on these Co O /N-rGO nanosheets demonstrates enhanced and stable electrochemical performance, even under severe deformation. Such batteries, for the first time, can be successfully knitted into clothes without short circuits under external forces and can power various electronic devices and even charge a cellphone.

CuCo2S4 Nanosheets@N‐Doped Carbon Nanofibers by Sulfurization at Room Temperature as Bifunctional Electrocatalysts in Flexible Quasi‐Solid‐State Zn–Air Batteries

“…[1,2] The operating voltages of ZABs can be easily enhanced by integrating the devices in parallel or series to satisfy high-voltage power and energy demands in practical applications. [1,2] The operating voltages of ZABs can be easily enhanced by integrating the devices in parallel or series to satisfy high-voltage power and energy demands in practical applications.…”

“…[1][2][3][4][5][6][7][8] In principle, the advancement of flexible ZABs is critically dependent on the availability of desired air electrodes with excellent bifunctional electrocatalysis for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), together with robust flexibility and mechanical strength. [1][2][3][4][5][6][7][8] In principle, the advancement of flexible ZABs is critically dependent on the availability of desired air electrodes with excellent bifunctional electrocatalysis for both oxygen evolution reaction (OER) and oxygen reduction reaction (ORR), together with robust flexibility and mechanical strength.…”

Recent Advances in Flexible Zinc‐Based Rechargeable Batteries

“…Such conversion mechanism suggests that their specific energy density partly depends on the choice of cathode materials. [15] The poor depth dischargeability of Zn (always less than 30%) is considered to be the main reason to this appearance as the discharge product of Zn(OH) 4 2− would easily convert to insoluble and nonconductive ZnO. With no doubt, Zn-air battery is the most promising system in terms of specific energy density.…”

“…[15,58] Whereas, since it is hard to assemble different components of battery together, especially coating an appropriate film www.advenergymat.de www.advancedsciencenews.com electrolyte around electrodes to keep them isolated, fabricating a 1D fiber-shaped flexible Zn-based batteries is still a challenge both in academic and industry communities. and can be knitted in to fabrics, exhibit superior advantages, and could be a promising solution toward wearable energy storage system.…”

“…Such batteries are freed from the constraints of rigidity and weight that characterize current portable batteries. [9][10][11][12][13][14][15] Companies working in rechargeable, polymer Zn-MnO 2 batteries have demonstrated that this new zinc secondary battery chemistry is well suited to a broad range of features for flexible electronics at reduced cost. To provide a power source for these applications, flexible batteries delivering a high volumetric energy density are particularly desirable because there is often a limited volume for integrating the batteries into these applications.…”