The flexible energy storage system used by wearable electronic devices has recently attracted widespread attention from the scientific community and the industrial community. Lithium-ion batteries and supercapacitors are currently the two main energy storage technologies and cannot satisfy the flexible energy storage system due to problems such as insufficient energy density. Requirement - to provide a sufficiently high and long enough energy supply in a limited space. A zinc-air battery with metal zinc as the anode and oxygen in the air as the cathode fuel has a high theoretical energy density (1084 Wh/kg) and low cost Such advantages are considered to be one of the next-generation flexible energy storage system options. However, the rate of oxygen reduction and oxygen precipitation reaction on the positive electrode of the air severely limits the actual energy density of the zinc-air battery, the charge and discharge stability, and durability. Such as performance and so on. Therefore how to prepare efficient, stable oxygen reduction and oxygen precipitation dual function catalyst has become the focus of the current research. Recently, atomic-level thickness of graphene-like two-dimensional material due to its unique electronic structure, large specific surface area, activity The advantages of multiple sites are highly sought after by scientific researchers. Therefore, Co3O4 (tetraoxygen) with excellent bifunctional catalytic performance in alkaline environment Tricobalt) materials are grapheneized, and effective compounding with graphene is of great significance for improving the performance of zinc-air cells. In addition, the one-dimensional fibrous structure has excellent flexibility, flexibility, and can be knitted into arbitrary and good human bodies. Appropriate shape. In summary, the preparation of high-performance woven fibrous hollow zinc battery has a strong role in the development of flexible energy storage systems.
At present, Tianjin University, Zhong Cheng, Deng Yida, Hu Wenbin and others have prepared a high-performance woven fibrous zinc empty battery. First, the research group uses a low-cost electrode material, a continuous, simple process path to prepare a Weaving fibrous zinc empty cells. Next, in order to improve the performance of woven fibrous Zn-air cells, the team used an in-situ composite method to cover the surface of NrGO (nitrogen-doped redox graphene) mesopore with an atomic thickness. Co3O4 nanosheets. The prepared Co3O4/N-rGO composite nanosheets exhibited excellent dual-function catalytic performance. It was found that in-situ compounding can increase the conductivity of Co3O4, and accelerate the electron transport during the catalytic reaction. The electronic structure of the composite material is also changed because of the strong coupling and synergistic interaction between the Co3O4 nanosheet and the N-rGO nanosheet, which facilitates the acceleration of the adsorption/desorption process of the oxygen medium. In addition, the atomic-scale thickness of the composite material The pore characteristics facilitate the exposure of more active sites and promote the mass transfer process. Flexible fibrous zinc empty battery cell with Co3O4/N-rGO composite nanosheet as air cathode catalyst Excellent charge/discharge performance, at a charge/discharge current density of 3 mA/cm3, discharge voltage 1.2 V, charge voltage 2 V, energy efficiency 60%. In addition, mass energy density up to 649 Wh/kg and 36.1 mWh/ The ultra-high volume energy density of cm3 also meets the requirements of high-energy-density flexible energy storage systems. In order to further verify the weavability of the prepared flexible fibrous zinc-air cells, the team conducted a series of demonstration work. The results were found to be incorporated into The flexible fibrous zinc empty battery in the fabric still works well and shows good resistance to external damage. Even more exciting is that the battery pack of the flexible fibrous zinc-air cells incorporated into the fabric can be connected in series and in parallel. Drive the LED electronic watch, charge the LED display and charge the iPhone.