Mercury-free zinc paste of button alkaline zinc-manganese dioxide cell and preparation method for mercury-free zinc paste

Abstract

The invention provides a mercury-free zinc paste of a button alkaline zinc-manganese dioxide cell and a preparation method for the mercury-free zinc paste. The preparation method comprises the following steps of: preparing the following raw materials in percentage by mass: 98 to 99.05 percent of mercury-free zinc powder, 0.4 to 1.9 percent of an adhesion agent, 0.01 to 0.6 percent of indium hydroxide and 0.05 to 1.5 percent of zinc oxide, wherein the adhesion agent comprises sodium carboxymethylcellulose and sodium polyacrylate, and the mass ratio of the sodium carboxymethylcellulose to the sodium polyacrylate is 0.1 to 10; grinding the raw materials in three-dimensional nonmetal ball milling mixing equipment for 5 to 100 minutes; adding electrolyte of which the mass is 38 to 43 percent of that of the mixture into the ball milling mixing equipment; vacuumizing the ball milling mixing equipment to be below 0.01 MPa; and mixing for 10 to 100 minutes to obtain the zinc paste. According to the preparation method, the used substances are mixed into a paste and treated under a vacuum condition, gases generated during the preparation of the zinc paste are exhausted, and the indium hydroxide is added to replace mercury so as to prevent the generation of gases, so that the environment is not polluted. Moreover, the sodium carboxymethylcellulose is added to prevent dispersed zinc powder from sedimentation and agglomeration because the viscosity of a zinc electrode is reduced, and the sodium carboxymethylcellulose acts together with the indium hydroxide to ensure that the cell shows high discharge performance. Therefore, the cell cannot deform by swelling, so that the cell can be conveniently stored, and the environment is not polluted because the indium hydroxide is added into the zinc paste to replace the mercury so as to prevent the generation of gases. The zinc paste prepared by the preparation method can be applied to mercury-free button cells.

Description

【Technical field】

[0001] The invention belongs to the technical field of batteries, in particular to a mercury-free zinc paste for a button-type alkaline zinc-manganese battery and its preparation. 【Background technique】

[0002] In alkaline zinc-manganese batteries, a certain amount of mercury is usually added as a corrosion inhibitor for zinc. This kind of mercury battery has large capacity and good storage performance. At present, the traditional production method of button batteries is to mix the anode active material with the binder, add it to the anode cup, and then add the electrolyte, so that the gas generated by the contact between the electrolyte and the active material is sealed in the battery, which is not conducive to battery storage; Moreover, mercury is added to the anode active material to prevent the generation of gas, which pollutes the environment. Zinc paste production is a key part of mercury-free button cells. Zinc paste is composed of main materials...

Images