Selection of zinc alloy powder for alkaline battery with low mercury content?

Today, People's awareness of environmental protection is increasing, the common alkaline batteries have achieved low mercury or even non-mercury, and the choice of alloy gold powder is the main improvement of low mercury alkaline batteries.

First, the zinc powder alloy should satisfy the following conditions:

1. It is difficult to be corroded in the electrolyte; 2. It has no harmful effect on the anode of zinc powder; 3. It contains no or little harmful additive elements; 4. The purity of zinc powder is higher; 5. The material cost does not increase much. Amalgamation of zinc powder in alkaline zn-mno _ 2 battery mainly increases the hydrogen overvoltage of zinc powder in the electro-hydraulic system and inhibits the occurrence of hydrogen in the alkaline system. The amalgamation film formed after amalgamation of zinc powder can cover the surface of zinc powder evenly, thus changing the surface condition of zinc powder and activating the zinc electrode, thus improving the battery's electrical performance and reducing the leakage rate of the battery. In the process of battery discharge, mercury is continuously diffused from the surface of the zinc particles to the interior of the zinc particles, so that the discharge is stable. Therefore, in order to maintain the corrosion resistance of zinc powder under the condition of low amalgamation rate, it is necessary to add some trace elements which can increase the hydrogen overpotential and prevent the mercury from diffusing into the zinc particles before the battery discharge, the specific surface area of zinc powder can be reduced without affecting the discharge reaction.

It can not only increase the hydrogen overvoltage on the surface of zinc alloy particles, but also make the zinc surface easy to form an alloy with mercury. Therefore, indium element is a necessary element for low-mercury zinc oxide or non-mercury zinc oxide powder. Other added elements are: lead, aluminum, bismuth, cadmium and so on, cadmium itself to hydrogen over-voltage high, so have good corrosion resistance, but they are more toxic, in some low mercury or mercury-free batteries as little or no use. Battery makers also use organic Surfactant and collector silver nails to make low-mercury alkaline batteries.