Porous zinc electrode, preparation method thereof and zinc-air battery comprising porous zinc electrode

Abstract

The invention provides a porous zinc electrode, a preparation method thereof and a zinc-air battery comprising the porous zinc electrode. The preparation method comprises the following steps: inserting a template with a porous structure as a cathode and zinc as an anode into an electroplating solution containing a ruthenium source, applying a current between the anode and the cathode for electroplating, and depositing a zinc layer on the surface of the template, and preparing the porous zinc electrode. The porous zinc electrode provided by the invention has a three-dimensional network-shaped porous structure, has obvious structural advantages compared with the traditional porous material with uniform aperture, and can be used as a metal anode of the zinc-air battery to further improve thecharge quantity of the zinc-air battery.

Description

technical field [0001] The invention belongs to the technical field of batteries, and relates to a porous zinc electrode, a preparation method thereof and a zinc-air battery comprising the same. Background technique [0002] With the rapid development of science and technology and the improvement of people's living standards, people continue to expand the use of battery products, and the consumption of batteries is increasing rapidly. At the same time, all kinds of new electronic products have more and more functions, more and more power, more and more energy consumption, and the requirements for battery varieties and performance are also constantly improving. At present, a large number of lead-acid batteries, lithium-ion batteries and nickel-metal hydride batteries are popular in the market. They either have low specific energy or high prices, which are difficult to meet market demand. [0003] Zinc-air batteries are a new type of chemical power source in which oxygen in t...

AI Technical Summary

Problems solved by technology

[0005] But at the same time, the disadvantages of zinc-air batteries are less obvious, as shown in: (1) The use cost is relatively high, and the charging process is relatively complicated

Because zinc-air batteries are usually charged mechanically, it is required to take out the zinc electrode and charge it in a special charging tank. Only professionals can operate it, which brings trouble to use, and also increases labor costs, resulting in additional actual operating costs. higher value

(2) The actual service life is short, 1 to 2 years, which is not mainly due to the poor electrochemical performance of the battery, but the impact of the structure of the battery

For example, the shell of the battery is made of plastic covering the air electrode, not a complete plastic tank, so it brings difficulties to the sealing of the battery, and many batteries leak after a certain period of use.

Secondly, the zinc-air electrode must be made porous. The porous electrode can absorb oxygen, but at the same time, it can also absorb some carbon dioxide, which will cause the electrolyte to be carbonated, resulting in a significant decrease in the efficiency of the battery.

(3) The batch production process is not mature enough

This is mainly the manufacture of catalytic membranes and waterproof and breathable membranes, most of which require semi-mechanical operations, and there are some manual factors that lead to differences in electrode performance

(4) The most difficult problem is that the battery is difficult to seal. When the zinc-air battery is discharged, it needs a steady stream of oxygen from the air to enter the battery, so the battery is not completely sealed. There are one or more air holes in the battery shell, so the inside of the battery connected to the outside

But obviously, this solution cannot guarantee a high contact area while preventing electrolyte leakage

[0009] It can be seen from the above that although zinc-air batteries have many advantages, their disadvantages are not obvious. On the one hand, the use of zinc flakes as the anode leads to a small contact surface with the electrolyte, and the zinc flakes produce electrons at a low speed, which affects The output current generally needs to be catalyzed by precious metals, liquid metals or other materials to increase the output current

Moreover, zinc ions are easy to form dendrites in an alkaline environment and adhere to the surface of zinc materials, which aggravates the above defects; on the other hand, zinc paste is mixed with zinc powder and electrolyte as the anode. It is separated from the shell and cannot be well sealed. The electrolyte flowing in the battery is prone to leakage and cause a short circuit of the battery, which greatly reduces the service life of the battery.

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