CN1224125C - Hot immersion plated foamed lead slab lattice for lead acid accumulator and its making process - Google Patents

Abstract

The present invention relates to a hot dip plating foam lead plate grid for lead acid batteries and a manufacturing method thereof. Foam copper is used as the substrate of the plate grid, and a hot dip plating method is adopted to plate lead or lead alloy on the surface of the foam copper in a dipping mode to obtain the foam lead plate grid. The method comprises: firstly, foam copper is preheated to 110 to 170 DEG C; secondly, the preheated foam copper is plated in liquid of lead or lead alloy at 320 to 380 DEG C for 5 to 25 min. The present invention solves the problems that the existing plate grid material can not satisfy requirements for high specific energy lead acid batteries, and the manufacturing method of the existing foam lead plate grid has the defects of complicated technical process and low production efficiency.

Description

Lead-acid battery hot-dip plated foamed lead grid and manufacturing method thereof

technical field

The invention relates to a lead-acid battery negative electrode foam lead grid and other manufacturing methods.

Background technique

Lead-acid batteries are widely used because of their low price, wide range of raw material sources, high output power, high charging and discharging efficiency and good safety. It is the most widely used secondary battery on the market.

With the advancement of technology and the improvement of environmental protection awareness, electric vehicles and hybrid vehicles have emerged at the historic moment and have achieved rapid development. It can be said that the development of batteries for high-energy vehicles is the development of electric vehicles and hybrid vehicles. One of the most critical technologies. In particular, the introduction and use of 36/42V vehicle power supply systems put forward higher requirements for automotive batteries. Considering the whole situation, the most realistic choice for automotive power supplies is still lead-acid batteries, but lead-acid batteries still face huge challenges. , That is, three major problems of lead-acid batteries must be solved or improved: 1. Improve specific energy and specific power; 2. Improve cycle life; 3. Improve fast charging capacity. In order to improve the performance of lead-acid batteries, countries have successively started from the lead-acid battery structure and grid materials, and invented some new grid materials and new lead-acid batteries. New grid materials include: copper expanded mesh grid, lead cloth, etc.; new lead-acid batteries include: winding batteries, horizontal batteries and bipolar batteries, etc. Although some results have been achieved, it still cannot meet the requirements of electric vehicles and hybrid vehicles. CN1147700A discloses a "manufacturing method of lead-acid battery negative electrode foamed lead grid", which uses foamed copper as a substrate, electroplates lead-tin alloy, then undergoes heat treatment, and then electroplates lead to obtain foamed lead. The process of the method is complicated and the production efficiency is low.

Contents of the invention

In order to solve the problems that current grid materials cannot meet the needs of high specific energy lead-acid batteries, and the existing manufacturing methods of foamed lead grids have complex process and low production efficiency, the invention provides a lead-acid battery hot-dip Foam-plated lead grid and its manufacturing method. The lead-acid battery hot-dip foamed lead grid of the present invention uses foamed copper as the matrix, adopts the method of hot-dip plating, and dips lead or lead alloy on the surface of the foamed copper at 320-380 ° C to obtain a foamed Lead grid. The preparation method of lead-acid battery hot-dip plating foamed lead grid of the present invention comprises the following steps: 1, preheating: foam copper is preheated to 110～170 ℃; Hot-dip plating in lead or lead alloy liquid for 5 to 25 minutes. The invention also includes hot air knife blowing after immersion plating, the temperature of the wind is 130-180° C., and the pressure of the wind is 0.25-0.50 MPa. The preheating of lead foam is preheated by hot air, the air temperature is 110-170°C, and the air pressure is 0.10-0.15MPa. The thickness of the hot-dip lead alloy layer is 10-300 μm. The invention takes a foamed lead grid with a suitable size and coats the negative active material to prepare the foamed lead negative electrode. The advantages of the present invention are: light weight, compared with cast alloy grids of the same size, the weight of the foamed lead grid is reduced by 50% to 70%; the area of the foamed lead grid is 5 to 20 times that of the cast grid, thus increasing the The contact area between the grid and the active material reduces the internal resistance and improves the utilization rate of the active material; the foamed lead negative electrode has a large capacity, and the capacity is increased by 10% to 50%; the specific energy is increased by 35% to 70%. Compared with the foamed lead grid made by electroplating, the present invention has simple process, high efficiency, continuous production, good mechanical properties of foamed lead, and controllable alloy composition (can be pure lead, lead-calcium, lead-tin, lead Calcium-tin-aluminum alloy), and can avoid the residue of fluoroborate ions in the internal pores of the foamed copper bars during the electroplating process, causing adverse effects on the performance of the lead-acid battery.

Description of drawings

Fig. 1 is the ten-hour charging and discharging voltage curve of the grid installed on the battery in the first embodiment, Fig. 2 is the high-current discharge voltage curve of the grid installed on the battery in the first embodiment, and Fig. 3 is the plate grid of the first embodiment The grid is installed on the low temperature discharge voltage curve of the battery.

Detailed ways

Specific embodiment one: cut the foamed copper of 44 * 70 * 2.5 (mm), weld on the lug lead bar, then preheat, and in the hot-dip lead-plating solution, carry out hot-dip lead-plating at 340 ℃ through 10min, The prepared foamed lead grid is coated with negative electrode active material to obtain a foamed lead electrode.

Compared with ordinary casting electrodes, the weight distribution of this foamed lead electrode is as follows, see Table 1.

Table 1 Comparison of the weight of foamed lead electrodes and ordinary casting electrodes Weight/g Foam lead negative electrode Cast grid negative electrode Grid weight/g lead paste weight/g negative electrode total weight/g 5.523.0028.50 13.0023.0036.00

It can be seen that the lead foam greatly reduces the weight of the grid by 58%, and the lead foam negative electrode is 21% lighter than the ordinary casting negative electrode.

Use the above two kinds of grids to assemble the battery, the battery with excess positive electrode (3 positive) and negative limit capacity (2 negative). Its specific volume and specific energy are shown in Table 2.

Table 2 Comparison of the properties of foamed lead electrodes and cast grid electrodes Discharge current/A Foam lead negative electrode Cast grid negative electrode Specific capacity/Ah kg ^-1 Specific energy/Wh kg ^-1 Specific capacity/Ah kg ^-1 Specific energy/Wh kg ^-1 I ₁₀ 112.2 224.4 85.0 170.0 I ₂ 80.2 160.4 57.2 114.4 I _big 57.6 115.2 38.2 76.4 I _low 65.8 131.6 46.2 92.4

The results in Table 2 show that the foamed lead electrode can significantly improve the specific capacity and specific energy of the lead-acid battery, especially in high current discharge and low temperature discharge, the advantages of the foamed lead grid are more obvious.

Figure 1 is the ten-hour rate charge and discharge voltage curves of experimental batteries made of two kinds of grid materials. From the experimental results in Figure 1, it can be seen that the discharge voltage of the two batteries is basically the same, while the charging voltage of the foamed lead grid is significantly reduced. It shows that the battery assembled with foam lead grid has good charging performance. Figure 2 is the experimental battery made of two kinds of grid materials, the large current discharge voltage curve. It can be seen that the discharge voltage of the battery assembled with the foamed lead grid is significantly improved. Fig. 3 is the low temperature discharge voltage curve of the experimental battery made of two kinds of grid materials. It can be seen that the discharge voltage of the experimental battery of the foamed lead grid is significantly improved at low temperature, the discharge voltage is high, and the discharge time is long. It shows that the foamed lead grid is beneficial to improve the low-temperature performance of the lead-acid battery.

Specific embodiment two: according to the method of Example 1, lead-plated calcium-tin-aluminum alloy is hot dipped to prepare a foamed lead grid.

Assemble into a flooded experimental battery with excess positive poles (2 positives) and negative limit capacity (1 negative). Its specific capacity is shown in Table 3.

Table 3 Comparison of specific capacity of batteries assembled with different electrodes Discharge current Foam lead negative electrode cast grid Improve rate I ₁₀ 123.5 92.6 33% I ₂ 94.3 66.3 42%

It can be seen that compared with the ordinary negative electrode battery, the foamed lead negative electrode battery can be discharged at a rate of 10 hours, and the capacity is increased by 33%. Discharge at a rate of 2 hours, the capacity increased by 42%.

Claims (5)

1. Lead-acid battery hot-dip foamed lead grid, which is characterized in that it uses foamed copper as the substrate, adopts the method of hot-dip plating, and dips lead or lead alloy on the surface of foamed copper at 320-380 °C, The prepared foam lead grid. 2. The manufacturing method of lead-acid battery hot-dip plated foamed lead grid is characterized in that it includes the following steps: 1. Preheating: preheating the foamed copper to 110-170 ° C; 2. Preheating the preheated foamed copper at 320 Hot-dip plating in lead or lead alloy liquid at ～380℃ for 5～25min. 3. The method for manufacturing lead-acid battery hot-dip-plated foamed lead grids according to claim 2, characterized in that it also includes post-processing the grids by blowing them with a hot air knife after dipping, and the temperature of the wind is 130 ~180°C, the wind pressure is 0.25~0.50MPa. 4. The method for making lead-acid battery hot-dip plated foamed lead grids according to claim 2, characterized in that the preheating of the foamed copper is preheated by hot air, the air temperature is 110-170°C, and the air pressure is 0.10- 0.15 MPa. 5. The method for manufacturing lead-acid battery hot-dip-plated foamed lead grid according to claim 2, characterized in that the thickness of the hot-dip lead-plated alloy layer is 10-300 μm.

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