Metal-air battery anode component with conductive hydrophobic expanded polytetrafluoroethylene film and preparation method thereof

Abstract

The invention discloses a metal-air battery anode component with a conductive hydrophobic expanded polytetrafluoroethylene (PTFE) membrane. The component comprises a conductive hydrophobic breathablelayer, a metal net layer and a catalytic layer which are sequentially arranged along the direction that oxygen enters a metal-air battery, and the conductive hydrophobic breathable layer is the conductive hydrophobic expanded PTFE membrane. The preparation method comprises the following steps: preparing the catalyst layer, the conductive hydrophobic expanded polytetrafluoroethylene PTFE membrane,the conductive glue and the metal or alloy mesh plate; printing or dispensing uniformly distributed conductive glue on the bonding surface of the conductive hydrophobic expanded polytetrafluoroethylene PTFE film and the metal or alloy mesh plate, and superposing the conductive hydrophobic expanded polytetrafluoroethylene PTFE film and the metal or alloy mesh plate; compressing, curing, and bonding. Through the above method, a good liquid blocking effect of the electrode can be ensured, and an effect that oxygen enters the electrode to react can also be ensured, so that the positive electrode conductivity of the metal-air battery is better. In addition, the service life of the metal-air battery using the component disclosed by the invention is far longer than the service life of other metal-air battery products in the working process.

Description

technical field [0001] The invention relates to a positive electrode component of a metal-air battery with a conductive hydrophobic expanded polytetrafluoroethylene film and a preparation method thereof. Background technique [0002] Main features of metal-air batteries: [0003] (1) High specific energy. Since the active material used in the air electrode is oxygen in the air, it is inexhaustible, and the capacity of the positive electrode is theoretically unlimited. In addition, the active material is outside the battery, so that the theoretical specific energy of the air battery is higher than that of the general metal oxide electrode. Much larger, the theoretical specific energy of metal-air batteries is generally above 1000W·h / kg, and the actual specific energy is above 100W·h / kg, which belongs to high-energy chemical power sources. The figure below shows the performance of some metal-air batteries. [0004] (2) The price is cheap. Zinc-air batteries do not use expe...

AI Technical Summary

Problems solved by technology

First, the battery cannot be sealed, which will easily cause the electrolyte to dry up and rise, which will affect the capacity and life of the battery. If alkaline electrolyte is used, carbonation will easily occur, which will increase the internal resistance of the battery and affect the discharge.

Second, the wet storage performance is poor, because the air in the battery diffuses to the negative electrode, which will accelerate the self-discharge of the negative electrode

Third, the use of porous zinc as the negative electrode requires amalgamation. Mercury not only endangers the health of workers but also pollutes the environment. It needs to be replaced by non-mercury corrosion inhibitors.

[0007] At present, the preparation process of the waterproof and breathable layer in the positive electrode of the existing metal-air battery is complicated. For example, in the document CN106910924, PTFE fine powder and conductive powder are mixed in water, and ethanol solvent is added after filtering and drying, and then rolling and heat treatment make some polymers Degradation forms large pores. In this method, the filtration and drying operations are cumbersome, and the size of the pores is not easy to control; in the document CN101831123, the concentration is 60% PTFE emulsion is mixed with conductive powder, and after drying, the film is rolled and rolled. Conductive film is prepared, and this method filtration, drying operation are more loaded down with trivial details, and the gas permeability of film is not easy to control; Document CN110120531 adopts 60% PTFE emulsion equally, is wetting agent and pore-forming agent with polyethylene glycol, and this scheme filters, The drying operation is cumbersome, and the size of the holes is not easy to control

The filtration and drying procedures in the above scheme are cumbersome, which is not conducive to large-scale production, and at the same time, the air permeability of the membrane is not easy to control

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