Process and Control of Mercury-Free Alkaline Battery

Date:2022-01-27
Summary:

With the increasing depletion of renewable energy, the […]

With the increasing depletion of renewable energy, the green call for environmental protection and energy saving has been responded to by practical actions. As a major country in battery production and consumption, my country has basically achieved mercury-free alkaline batteries. In the industrial production of mercury-free alkaline batteries, battery manufacturers usually need to control the following processes:

1. Improve the conductivity of zinc paste
The "wetness" of mercury helps the connection between zinc powder and between zinc powder and current collector, improves the conductivity of zinc paste, and makes the battery have better anti-vibration performance. To improve the electrical conductivity of the zinc paste, we can start from using a zinc paste thickener with high viscosity and stability, properly increasing the proportion of zinc powder in the zinc paste, and adding other conductive materials to the zinc paste.

2. Pay attention to the influence of Cu and ultrafine zinc powder on mercury-free batteries
During the production process, the pollution of Cu must be strictly controlled, and the ultrafine particles in the mercury-free zinc powder should be limited to prevent the short circuit of the battery caused by the migration of the zinc powder. Because copper easily migrates from the cathode to the anode, zinc in the anode accelerates the migration of ultrafine particles to the cathode, so that copper ions and Zn are prone to redox reactions, and the formed copper hydroxide dendrites gradually penetrate the diaphragm and form a short circuit.

3. Control carbonation
Effective control of carbonation of positive and negative electrodes in the production process is one of the important technological measures for mercury-free alkaline batteries. First of all, the concentration of CO2 in the air must be controlled. The preparation of zinc paste is carried out under vacuum conditions. The electrolyte, zinc paste and positive electrode powder must be sealed and packaged. Secondly, protective covers should be added to the equipment and conveying tracks before the sealing process to reduce air exchange and prevent carbonation of battery products.

4. Control the pollution in the production process
The production of mercury-free alkaline zinc-manganese batteries must maintain a clean production environment and a pollution-free production process. The entire production process should be dust-free to prevent the introduction of impurities that increase zinc and hydrogen evolution. The intermittent processing method of spare parts requires many manual operations, the pollution of parts cannot be controlled, and the quality cannot be guaranteed.