Method for modifying lead storage battery positive plate by rare earth

Abstract

The invention discloses a method for modifying a lead storage battery positive plate by rare earth. The method comprises the steps that in a battery formation process of a lead storage battery positive plate, rare earth sulfate or rear earth oxide is added to a battery formation liquid, rare earth ions generate an oxidation reaction at the anode to modify the lead storage battery positive plate, and when a lead compound on the positive plate is converted to lead dioxide, the rare earth modifies a battery positive grid and positive electrode active substances, so that the performance of the lead storage battery is improved. The method is simple; a trace of rare earth can be easily uniformly and quantitatively mixed on the surface of an electrode so that the control on the performance of the electrode surface is realized; the device investment is low, the process improvement is large, the method can be suitable for different electrodes, the use amount of the rare earth is largely reduced, and the utilization ratio of the rare earth is improved; by utilizing an electrochemical technology as an electrode surface rare earth modification technology, the use amount of the rare earth is largely reduced, the utilization ratio of the rare earth is improved, the large-scale industrial production is facilitated, and the control on the electrode surface performance is realized.

Description

technical field [0001] The invention belongs to the technical field of preparation of positive plates of lead storage batteries, and in particular relates to a method for modifying the positive plates of lead storage batteries with rare earths. Background technique [0002] Lead-acid batteries have the advantages of simple structure, convenient use, reliable performance, and low price. Therefore, they are widely used in various sectors of the national economy. They have always been the product with the largest output and wide application range in chemical power sources. In terms of R&D and application, the performance of lead-acid batteries has been greatly improved, and the advantages of new lead-acid batteries in some special application fields have become more apparent. As electric mopeds, special electric vehicles, and new-type automobile power supplies, they are still mainstream power supplies in the near future. However, the high-current discharge characteristics of po...

AI Technical Summary

Problems solved by technology

[0014](1) There are problems of corrosion and reduced conductivity of the positive grid during use: during the use of the positive grid, especially under overcharged operating conditions, The grid is prone to oxidation reaction, corrosion and reduced conductivity

[0015](2) The performance deterioration of the positive electrode active material: With the increase of the number of charge and discharge cycles, the discharge capacity gradually decreases

The main problem is that the particle binding force is reduced, the electrical contact is broken, and the resistance increases accordingly

In addition, in the later stage of each charge, oxygen is precipitated on the positive electrode, and under the impact of oxygen evolution, the binding force of the active material is further weakened, causing the falling off of the active material and the combination of the grid and the active material to become weaker, and the active material of the positive electrode becomes weaker. It is easy to soften and fall off; the electrode reaction is preferentially carried out on the electrode surface, and the reaction product PbSO4 is a poor conductor, so that the internal resistance of the battery increases with discharge, and at the same time PbSO4 converts PbO Enclosed by 2, PbSO4 with a molar volume larger than PbO2 blocks the pores of the porous electrode, making the reactant H2SO4 cannot diffuse smoothly into the depth of the electrode, resulting in more unreacted substances remaining, resulting in a decrease in the utilization rate of positive active materials

[0016](3) Matching of the active material of the positive plate of the lead-acid battery and the positive grid: in the prior art, the positive grid and the positive active material are basically mechanically attached, There are problems such as insufficient contact adhesion and shedding of the positive active material during the use of lead-acid batteries

[0020] (2) The preparation conditions are inconsistent with the use conditions: adding rare earths to sulfuric acid aqueous solution, and using electrochemical pre-electrolysis to prepare rare earth modified battery positive plates to improve the performance of lead-acid batteries. However, when the positive plate of the battery is modified with rare earths to improve the performance of the lead-acid battery during use, the content of rare earth substances in the positive plate of the battery is reduced, and the performance of the battery decreases during the use of the battery

[0021](3) Process pollution: After the pre-electrolysis treatment, it is necessary to carry out the operation steps such as washing and drying, which will generate a large amount of acid mist and waste acid, which will not only make resource utilization Small reduction in efficiency, and pollute the ambient temperature

[0022](4) Pre-electrolysis treatment: Electrochemical treatment is carried out in the pre-electrolysis equipment, resulting in an increase in the operation process of equipment and operating units

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