Ultrathin titanium substrate grid and lead-acid battery

Abstract

The invention discloses an ultrathin titanium substrate grid and a lead-acid battery, and belongs to the technical field of lead-acid batteries. In order to solve the problem that the energy density of a lead-acid battery is reduced due to the fact that the total weight ratio of an existing lead-acid battery grid on a polar plate is too high, the thickness of the ultrathin titanium-based grid is 0.1-0.18 mm, the ideal thickness of the ultrathin titanium-based grid is 0.15 mm, a titanium-based grid body is of a pull net type structure, and the diagonal size of rhombic meshes is 0.5-1.5 mm * 0.5-1.5 mm; a covered edge is arranged around the grid body, and the width of the covered edge is 0.5-1.0 mm; a tab is arranged at a position 5.0-10.0 mm away from a center line in the width direction of the grid, and a screw hole is formed in a position 3.0-5.0 mm away from the upper end of the tab and used for being connected with a positive electrode and a negative electrode respectively. According to the ultrathin titanium-based grid, the density is reduced while high mechanical strength is reserved, the number of positive and negative grids used by a 2V4Ah lead-acid battery adopting the ultrathin titanium-based grid is not more than 4, the weight of each grid is about 2-3 g, and the energy density of the battery can reach 70 Wh / kg.

Description

Technical Field

[0001] The invention belongs to the technical field of lead-acid batteries. Background Art

[0002] Lead-acid batteries are one of the most mature and widely used secondary batteries. Facing the challenge of new high-energy secondary batteries, people have been constantly improving this battery and improving its performance. However, compared with advanced secondary batteries such as lithium-ion batteries, lead-acid batteries have obvious shortcomings. The most important problem is that the energy density of lead-acid batteries is low, about 30-40Wh / kg, while the energy density of lithium-ion batteries is 120-250Wh / kg, which is about 5-10 times that of lead-acid batteries.

[0003] The grid of lead-acid batteries is generally made of lead alloy. Due to the corrosion of the positive grid, the active material will fall off. Therefore, the grid of the positive plate is generally thicker than that of the negative plate, about 2.2-2.4mm, and the thickness of the negative grid is 1.6-1.8mm. The density of lead is about 11.34g / cm 3 , the mass of the grid accounts for 33-50% of the total weight of the battery plate, resulting in a very low energy density of lead-acid batteries. Therefore, there is an urgent need to find a low-density, corrosion-resistant grid material as a substitute for the lead-acid grid. People have found that titanium alloy materials can not only meet the above requirements, but also have higher mechanical strength, making it possible to significantly reduce the thickness of the titanium alloy grid as the positive and negative electrodes.

[0004] At present, lightweight grids for lead-acid batteries generally use materials with lower density to reduce the overall mass of the plate, or improve the utilization rate of active materials by changing the arrangement of the ribs of the grid. In Chinese patent application: 202010406012.X "A carbon-containing lightweight grid for lead-acid batteries and its preparation method", a carbon-based composite material is used as a lightweight grid with a thickness of 1.5-4.0 mm. In Chinese patent application: 202410492879.X "A aluminum-based lead alloy mesh grid plate for lead-acid energy storage batteries and its preparation method", an aluminum alloy is used as a lightweight grid with a thickness of 2.0-6.0 mm. In Chinese patent application: 202310533965.6 "A lead-acid battery using a titanium-based grid and its preparation method", a titanium alloy is used as a grid substrate. After treatment, the thickness of the grid is 1 mm. In the Chinese patent application: 201910365706.0 “A new type of lightweight lead-acid power battery grid”, lead grids are still used, and the current collection capacity of the battery plates is improved by changing the direction of the ribs in the grid.

[0005] The improved lead-acid battery grid mentioned above has a thickness that is generally no different from that of an ordinary grid or even thicker, so that the weight proportion of the grid in the plate is not significantly reduced, and has little effect on improving the battery energy density. Summary of the invention

[0006] The present invention aims to solve the problem that the lead-acid battery grid accounts for too high a proportion of the total plate weight, resulting in a decrease in the energy density of the lead-acid battery, and designs an ultra-thin titanium-based grid and a lead-acid battery using the ultra-thin titanium-based grid.

[0007] The technical solution adopted by the present invention is as follows: An ultra-thin titanium-based grid, wherein the thickness of the ultra-thin titanium-based grid is 0.1-0.18 mm, the titanium-based grid body has a drawn-net structure, the diagonal size of the diamond mesh is 0.5-1.5 mm×0.5-1.5 mm, the thickness of the titanium wire is the same as the thickness of the grid, the titanium-based grid body is provided with titanium-based edging all around, the edging width is 0.5-1.0 mm, a pole ear is provided at 5.0-10.0 mm on the center line in the width direction of the grid, and a screw hole is provided at 3.0-5.0 mm on the upper end of the pole ear for connecting positive and negative electrodes respectively.

[0008] Preferably, the grid is made of TA2 or TA3 titanium alloy.

[0009] Further preferably, the ultra-thin titanium base grid has a thickness of 0.15 mm.

[0010] Further preferably, a lead-acid battery using the ultra-thin titanium-based grid, wherein the surface of the grid used as the positive electrode or the negative electrode in the battery is electroplated with a lead metal layer of 50-100 μm; Preferably, the grid used as the positive electrode further comprises a tin antimony oxide protective coating with a thickness of 0.1 to 100 μm between the lead metal layer and the titanium substrate.

[0011] Preferably, the grid used as the negative electrode further comprises a metal copper protective coating with a thickness of 0.1 to 100 μm between the lead metal layer and the titanium substrate.

[0012] Preferably, the grid size is 30-40 mm×60-70 mm, for use in 2V4Ah lead-acid batteries; the grid tab size is (2.0-6.0) mm×(30-50) mm.

[0013] Further preferably, the method for preparing the positive plate of the lead-acid battery comprises the following steps: (1) soaking the ultra-thin titanium-based grid in deionized water for ultrasonic treatment for 10 minutes, and then soaking it in a hydrochloric acid solution for 60 minutes to remove oil stains and aluminum oxide sandblasting on the surface of the titanium-based grid; (2) treating the ultra-thin titanium-based grid with chemical coating to form a complete tin-antimony oxide coating thereon; (3) Using lead fluoroborate solution as an electrodeposition solution, a lead metal layer is formed on the tin antimony oxide coating by electrodeposition.

[0014] Preferably, the hydrochloric acid solution in step (1) is obtained by diluting 1 part by volume of concentrated hydrochloric acid and 9 parts by volume of deionized water.

[0015] Preferably, the preparation method of the tin antimony oxide coating in step (2) is: dissolving tin chloride and antimony chloride in isopropanol at a molar ratio of 1:5-20 to obtain a coating solution, drying the titanium-based grid coated with the coating solution at 80-120°C for 2-10 minutes, then pyrolyzing at 300-600°C for 2-10 minutes, repeating the coating, drying and pyrolyzing steps 5-15 times, and finally sintering at 300-600°C for 30-120 minutes.

[0016] Preferably, in step (3), the lead fluoroborate solution is 100-150 ml / L, and the electrodeposition is carried out by electroplating with a current density of 10-50 mA / cm 2 The electroplating time is 0.5-3 hours, and the thickness of the electroplated lead layer is 50-200μm.

[0017] Further preferably, the method for preparing the negative plate of the lead-acid battery comprises the following steps: (1) soaking the ultra-thin titanium-based grid in deionized water for ultrasonic treatment for 10 minutes, and then soaking it in a hydrochloric acid solution for 60 minutes to remove oil stains and aluminum oxide sandblasting on the surface of the titanium-based grid; (2) treating the ultra-thin titanium-based grid by chemical plating to form a complete metal copper coating thereon; (3) Using lead fluoroborate solution as an electrodeposition solution, a lead metal layer is formed on the tin antimony oxide coating by electrodeposition.

[0018] Preferably, the hydrochloric acid solution in step (1) is obtained by diluting 1 part by volume of concentrated hydrochloric acid and 9 parts by volume of deionized water.

[0019] Preferably, the preparation method of the metal copper coating in step (2) is: sensitizing the titanium-based grid in a 10-20 g / L stannous chloride solution for 3-7 minutes, activating the sensitized titanium-based grid in a 3-6 g / L silver ammonia solution for 3-7 minutes, and precipitating the activated titanium-based grid in a 7-15 g / L copper sulfate solution for 5-10 hours.

[0020] Preferably, in step (3), the lead fluoroborate solution is 100-150 ml / L, and the electrodeposition is carried out by electroplating with a current density of 10-50 mA / cm 2 The electroplating time is 0.5-3 hours, and the thickness of the electroplated lead layer is 50-200μm.

[0021] Preferably, each battery cell in the lead-acid battery has 2 positive plates and 2 negative plates.

[0022] Beneficial effects of the present invention: (1) The ultra-thin titanium-based grid provided by the present invention has a thickness of no more than 0.18 mm and a coating thickness of several tens of micrometers, which is one-fourth the thickness of an ordinary lead alloy grid. Thanks to the low density and high mechanical strength of titanium, the weight of the titanium-based grid is only one-tenth of that of a lead grid and only accounts for 10-15% of the total weight of the plate.

[0023] (2) The ultra-thin and ultra-light titanium-based grid provided by the present invention has good corrosion resistance. The protective intermediate layer and the electroplated lead layer increase the bonding between the grid and the active material. The positive electrode active material is not easy to fall off, so that the positive and negative plates can maintain the same thickness. Therefore, there is no need to use more negative electrodes to match thicker negative electrodes, which reduces the use of negative plates, greatly reduces the overall quality of the battery, and greatly increases the overall energy density of the battery, reaching 70Wh / kg.

[0024] (3) Batteries using ultra-thin titanium-based grids still maintain a high cycle life and battery capacity. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] Figure 1 This is a front view of the grid structure of a titanium-based lead-acid battery grid.

[0026] Figure 2 It is a three-dimensional diagram of the grid structure of a titanium-based lead-acid battery grid.

[0027] Figure 3 It is a structural stereogram of a titanium-based lead-acid battery case.

[0028] Figure 4 This is a graph of the battery cycle life of Example 2.

[0029] Figure 5 This is a discharge energy diagram of Example 3. DETAILED DESCRIPTION

[0030] The technical solution of the present invention is further explained and illustrated in the form of specific embodiments below.

[0031] Example 1 This embodiment provides a 2V4Ah titanium-based lead-acid battery having two positive plates and two negative plates, using one battery grid, wherein the positive plates and the negative plates are made of ultra-thin titanium-based grids.

[0032] like Figure 1As shown, the ultra-thin titanium-based grid has a thickness of 0.15mm and a size of 40mm×70mm. The titanium-based grid body 1 has a drawn-mesh structure, the diagonal size of the diamond mesh is 0.5-1.5mm×0.5-1.5mm, and the thickness of the titanium wire is 0.1-0.18mm; a pole ear 2 is provided at 5.0-10.0mm on the center line of the grid width direction, and a titanium-based edging 4 is provided around the titanium-based grid body 1, and the edging width is 0.5-1.0mm. A screw hole 3 is provided at 3.0-5.0mm on the upper end of the pole ear for connecting the positive and negative electrodes respectively.

[0033] like Figure 3 As shown, each titanium-based grid forms a plane, each grid is parallel to each other, and the positive plate and the negative plate are connected in parallel at the pole ears using titanium screws.

[0034] The grid material in this embodiment is TA2 titanium alloy, which is obtained by forming in a metal expander and flattening the expanded metal under a roller.

[0035] The steps of preparing the lead-acid battery positive plate are as follows: (1) The ultra-thin titanium-based grid is immersed in deionized water for ultrasonic treatment for 10 minutes, and then immersed in a hydrochloric acid solution for 60 minutes to remove oil stains and aluminum oxide sandblasting on the surface of the titanium-based grid; the aluminum oxide sandblasting refers to the removal of the aluminum oxide frosted protective layer sprayed to prevent oxidation of the titanium alloy grid, and the protective layer can be removed by immersion in a hydrochloric acid solution obtained by diluting 1 volume part of concentrated hydrochloric acid and 9 volume parts of deionized water.

[0036] (2) Treating the ultra-thin titanium-based grid using chemical coating: Tin chloride and antimony chloride are dissolved in isopropanol in a molar ratio of 1:5-20 to obtain a coating solution, the titanium-based grid coated with the coating solution is dried at 80-120°C for 2-10 minutes, then pyrolyzed at 300-600°C for 2-10 minutes, the coating, drying and pyrolysis steps are repeated 5-15 times, and finally sintered at 300-600°C for 30-120 minutes to form a complete tin-antimony oxide coating.

[0037] (3) Using a lead borate fluoride solution as an electrodeposition solution, a lead metal layer is formed on the tin antimony oxide coating by electrodeposition; the lead borate fluoride solution has a concentration of 100-150 ml / L, and the electrodeposition is performed by electroplating with a current density of 10-50 mA / cm 2 The electroplating time is 0.5-3 hours, and the thickness of the electroplated lead layer is 50-200μm.

[0038] The preparation method of the lead-acid battery negative plate comprises the following steps: (1) The steps are the same as the positive plate; (2) Using chemical plating to process the ultra-thin titanium-based grid: The titanium-based grid is placed in a 10-20 g / L stannous chloride solution for sensitization for 3-7 minutes, the sensitized titanium-based grid is placed in a 3-6 g / L silver ammonia solution for activation for 3-7 minutes, and the activated titanium-based grid is placed in a 7-15 g / L copper sulfate solution for precipitation for 5-10 hours to form a complete metal copper coating thereon; (3) The steps are the same as the positive plate; The present embodiment provides a 2V4Ah lead-acid battery, which is a multi-battery unit structure. Each battery unit has 2 positive plates and 2 negative plates, wherein the active material on the positive plate is lead dioxide, and the active material on the negative plate is lead. The plates are separated by a non-conductive AGM diaphragm, and the battery electrolyte is sulfuric acid. The size of the battery is roughly the same as that of similar batteries, but the weight is only two-thirds of that of similar batteries, and the energy density is 1.5 times that of similar batteries. A general 2V4Ah lead-acid battery has 2 positive plates and 3 negative plates, while the lead-acid battery using the titanium-based grid of the present invention reduces the use of negative plates and only uses 2 negative plates.

[0039] Example 2 This embodiment provides a lead-acid battery using titanium-based grids. The difference between this embodiment and embodiment 1 is that the thickness of the positive and negative grids is different: the thickness of the titanium-based grid is 0.18 mm, and the size of the titanium-based grid is 40 mm × 70 mm. Two titanium-based positive plates and two titanium-based negative plates are assembled into a 2V4Ah lead-acid battery. Figure 2 As shown, the battery was tested under a simulated battery 2-hour rate discharge 100% DOD, and the battery life reached 350 times.

[0040] Example 3 This embodiment provides a lead-acid battery using titanium-based grids. The difference between this embodiment and embodiment 1 is that the number of assembled battery grids is 1 titanium-based positive plate and 1 titanium-based negative plate, and the assembled battery is a 2V2Ah lead-acid battery. Figure 5 As shown, the 10-hour rate discharge capacity of the battery is 2Ah.

[0041] The above embodiments are only preferred schemes of the present invention. In other embodiments of the present invention, the tin antimony oxide protective layer and the chemical copper plating protective layer may not be coated, and the electroplated lead layer may be directly used as the protective layer of the titanium-based grid, which has the same technical effect.

Claims

1. An ultra-thin titanium-based grid, characterized in that: The thickness of the ultra-thin titanium-based grid is 0.1-0.18 mm, the titanium-based grid body has a drawn-net structure, the diagonal size of the diamond mesh is 0.5-1.5 mm×0.5-1.5 mm, the titanium-based grid body is surrounded by titanium-based edging, and a pole ear is provided at 5.0-10.0 mm on the center line of the grid width direction, and a screw hole is provided at 3.0-5.0 mm on the upper end of the pole ear for connecting the positive and negative electrodes respectively.

2. The ultra-thin titanium-based grid according to claim 1, characterized in that: The grid is made of TA2 or TA3 titanium alloy.

3. The ultra-thin titanium-based grid according to claim 1, characterized in that: The thickness of the ultra-thin titanium-based grid is 0.15 mm.

4. A lead-acid battery using the ultra-thin titanium-based grid as claimed in claim 1, characterized in that: The surface of the grid used as the positive electrode or negative electrode in the battery is electroplated with a 50-100μm lead metal layer.

5. The lead-acid battery with an ultra-thin titanium-based grid according to claim 4, characterized in that: The grid used as the positive electrode also includes a tin-antimony oxide protective coating with a thickness of 0.1 to 100 μm between the lead metal layer and the titanium substrate; the grid used as the negative electrode also includes a metal copper protective coating with a thickness of 0.1 to 100 μm between the lead metal layer and the titanium substrate.

6. The lead-acid battery with an ultra-thin titanium-based grid according to claim 5, characterized in that: The preparation method of the lead-acid battery positive plate comprises the following steps: (1) soaking the ultra-thin titanium-based grid in deionized water for ultrasonic treatment for 10 minutes, and then soaking it in a hydrochloric acid solution for 60 minutes to remove oil stains and aluminum oxide sandblasting on the surface of the titanium-based grid; (2) treating the ultra-thin titanium-based grid with chemical coating to form a complete tin-antimony oxide coating thereon; (3) using a lead fluoroborate solution as an electrodeposition solution to form a lead metal layer on the tin antimony oxide coating by electrodeposition; The preparation method of the lead-acid battery negative plate comprises the following steps: (1) The process is the same as step (1) of the positive electrode plate preparation method; (2) treating the ultra-thin titanium-based grid by chemical plating to form a complete metal copper coating thereon; (3) The same as step (3) of the positive electrode preparation method.

7. The lead-acid battery with an ultra-thin titanium-based grid according to claim 6, characterized in that: The hydrochloric acid solution in step (1) of the method for preparing a positive electrode plate or a negative electrode plate of a lead-acid battery is obtained by diluting 1 volume part of concentrated hydrochloric acid and 9 volume parts of deionized water.

8. The lead-acid battery with an ultra-thin titanium-based grid according to claim 6, characterized in that: In the step (3) of the method for preparing the positive or negative plate of a lead-acid battery, the lead fluoroborate solution is 100-150 ml / L, the electrodeposition is carried out by electroplating, and the current density is 10-50 mA / cm 2 The electroplating time is 0.5-3 hours, and the thickness of the electroplated lead layer is 50-200μm.

9. The lead-acid battery with an ultra-thin titanium-based grid according to claim 6, characterized in that: The preparation method of the tin antimony oxide coating in step (2) of the lead-acid battery positive plate preparation method is as follows: tin chloride and antimony chloride are dissolved in isopropanol at a molar ratio of 1:5-20 to obtain a coating solution, the titanium-based grid coated with the coating solution is placed in a temperature range of 80-120°C for drying for 2-10 minutes, and then pyrolyzed at 300-600°C for 2-10 minutes, the coating, drying and pyrolysis steps are repeated 5-15 times, and finally sintered at 300-600°C for 30-120 minutes; The preparation method of the metal copper coating in step (2) of the lead-acid battery negative plate preparation method is as follows: sensitizing the titanium-based grid in a 10-20 g / L stannous chloride solution for 3-7 minutes, activating the sensitized titanium-based grid in a 3-6 g / L silver ammonia solution for 3-7 minutes, and precipitating the activated titanium-based grid in a 7-15 g / L copper sulfate solution for 5-10 hours.

10. The lead-acid battery with an ultra-thin titanium-based grid according to claim 4, characterized in that: The grid size is 30-40 mm×60-70 mm; the grid tab size is 2.0-6.0 mm×30-50 mm; each battery cell in the lead-acid battery has 2 positive plates and 2 negative plates.

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