A large-capacity single-cell battery built-in row and its manufacturing method

Abstract

A large-capacity single-cell battery built-in row is configured as a "concave" shape, with cylindrical ends and a concave connecting piece in the middle. The built-in row includes a copper row, a lead layer, and a circular cavity. The copper row is configured as a concave sheet, with connecting rings provided at both ends. The lead layer is wrapped around the outside of the copper row, and the lead layer wrapped around the surface of the connecting ring forms a cylinder at both ends of the built-in row. The circular cavity is provided in the cylinders at both ends of the built-in row. The circular cavity includes a frustum cavity and a cylindrical cavity that are connected. The frustum cavity is provided at the top of the cylindrical cavity, and the top diameter of the frustum cavity is larger than the bottom diameter. The connecting ring is located on the outside of the frustum cavity. The middle pole is inserted into the circular cavity, and the welding column at the top of the middle pole is welded in the frustum cavity. The present invention uses a copper row with low resistivity embedded in the lead as a connecting component between pole groups, thereby reducing the resistance of the built-in row and improving the high-current or high-power discharge capacity of the battery.

Description

Technical Field

[0001] The invention relates to a built-in continuous row of large-capacity single storage batteries and a manufacturing method thereof, belonging to the technical field of storage batteries. Background Art

[0002] Due to the external size requirements of large-capacity single-cell batteries, the electrode groups need to be split into 2 or 4, and the battery internal parallel connection is adopted to achieve the purpose of large capacity and single-cell batteries. This requires that the connection material between the electrode groups has a low resistivity. The internal connection material of conventional lead-acid batteries is lead (using other materials will intrude impurities and affect the battery self-discharge). The resistivity of lead is 0.2083Ω·mm 2 / m, the length of the built-in connecting wire connecting the two pole groups is long, which causes the temperature of the metal connecting wire to rise and the resistance to increase when the battery is discharged at high current and high power, resulting in serious energy loss of the built-in connecting wire, which directly affects the discharge capacity of the battery. Summary of the Invention

[0003] In order to overcome the drawbacks of the existing technology, the present invention provides a large-capacity single-cell battery built-in battery and a manufacturing method thereof. A copper battery with low resistivity is embedded inside the lead as a connecting component between the electrode groups, thereby reducing the resistance of the built-in battery and improving the high-current or high-power discharge capacity of the battery.

[0004] The technical solution adopted by the present invention to solve its technical problem is:

[0005] A built-in battery pack of large-capacity single-cell batteries, wherein the built-in battery pack is configured as a "concave" shape, with cylinders at both ends and a concave connecting piece in the middle. The built-in battery pack includes a copper battery pack, a lead layer and a circular cavity. The copper battery pack is configured as a concave sheet, with connecting rings provided at both ends. The lead layer is wrapped around the outside of the copper battery pack, and the lead layer wrapped around the surface of the connecting ring forms the cylinders at both ends of the built-in battery pack. The circular cavity is provided in the cylinders at both ends of the built-in battery pack. The circular cavity includes a frustum cavity and a cylindrical cavity that are connected. The frustum cavity is provided at the top of the cylindrical cavity, the top diameter of the frustum cavity is larger than the bottom diameter, the connecting ring is located on the outside of the frustum cavity, the middle pole is inserted into the circular cavity, and the welding column at the top of the middle pole is welded in the frustum cavity, completely wrapping the exposed part of the copper battery pack in the lead layer.

[0006] The above-mentioned large-capacity single battery is built-in in a row, and the thickness of the lead layer wrapped around the non-welded parts a, b, c and d outside the copper row is ≥3mm.

[0007] The above-mentioned large-capacity single battery cells are built in a row, and the height of the frustum cavity is h1≥6mm.

[0008] The above-mentioned large-capacity single battery cells are built in a row, and the height h2 of the cylindrical cavity is the same as the height h3 of the column of the middle-linked pole.

[0009] The above-mentioned large-capacity single battery cells are built in a row, and the inner diameter φ1 of the cylindrical cavity is 0.3mm-0.8mm larger than the diameter φ2 of the column.

[0010] The above-mentioned large-capacity single battery cells are built in a row, and the angle θ between the inner wall of the frustum cavity and the outer wall of the welding column is ≥60°.

[0011] The above-mentioned large-capacity single battery has a built-in copper busbar, and the copper busbar is a tin-nickel alloy with a tin content of ≥90% and the rest being nickel.

[0012] A method for preparing a built-in battery pack of large-capacity single-cell batteries comprises heating a copper battery pack to 40±5°C, suspending and inverting the copper battery pack in a built-in battery pack mold, and pouring lead into the built-in battery pack mold to form a built-in battery pack having a lead layer wrapped around the outer layer of the copper battery pack and having circular cavities at both ends.

[0013] The above-mentioned preparation method of built-in continuous rows of large-capacity single-cell batteries, the built-in continuous row mold includes a mold body and an operating handle, the operating handle is connected to one end of the mold body, the mold body is provided with a mold cavity, the mold body located at the bottom of both ends of the mold cavity forms a mold column base, the shape and size of the mold column base are the same as the shape and size of the inverted circular cavity, the copper continuous row is inverted in the mold cavity, the connecting rings at both ends are sleeved on the outer wall of the lower end of the mold column base, and the remaining part is suspended in the mold cavity, lead is poured into the mold cavity, and the height of the lead layer does not exceed the height of the top of the mold column base.

[0014] The beneficial effects of the present invention are:

[0015] The built-in busbars of the present invention adopt a structure in which lead is wrapped around the outside of the copper busbars, which has low resistance and small voltage drop. After being welded to the central pole, the copper is completely wrapped inside the lead layer, thereby improving the high-current or high-power discharge capacity of the battery and avoiding the influence of copper exposure inside the battery on the self-discharge performance of the battery. The present invention limits the lead layer thickness on the outside of the copper connecting strip to ≥3mm, thereby improving the service life of the built-in connecting strip; the angle θ between the inner wall of the frustum cavity at both ends of the built-in connecting strip and the outer wall of the welding column at the upper end of the middle pole is ≥60°, and the inner diameter φ1 of the cylindrical cavity is 0.3mm-0.8mm larger than the diameter φ2 of the column, thereby ensuring that the lead does not flow during welding and the welding effect of the middle pole is achieved, and after welding, the copper is completely sealed inside the lead layer; the copper connecting strip is a tin-nickel alloy with a tin content of ≥90% and the rest being nickel, thereby ensuring the bonding effect between the copper connecting strip and the lead layer; the height h2 of the cylindrical cavity is the same as the height h3 of the column of the middle pole, which facilitates the positioning of the built-in connecting strip and the middle pole on the parallel pole group; the height of the frustum cavity is h1 ≥6mm, thereby avoiding poor welding and ensuring a sufficiently effective current transmission area during large current discharge.

[0016] The mold for the built-in continuous strips of copper wires of the present invention has a simple structure, a simple process for preparing the built-in continuous strips, and high production efficiency. The inner diameter φ3 of the connecting rings at both ends of the copper continuous strips, the diameter φ4 of the exposed copper portion of the built-in continuous strips, and the diameter φ5 of the connecting rings of the copper continuous strips at the mold column base are all the same, ensuring that the thickness of the lead layer in the non-welded portions a, b, c, and d after casting is ≥3mm, thereby ensuring the service life and performance of the built-in continuous strips. BRIEF DESCRIPTION OF THE DRAWINGS

[0017] Figure 1 This is a schematic diagram of the built-in row structure of the present invention;

[0018] Figure 2 This is a schematic diagram of the copper busbar structure from the side;

[0019] Figure 3 This is a schematic diagram of the copper busbar structure from a top view;

[0020] Figure 4 This is a schematic diagram of the connection structure of the built-in pole in the middle pole;

[0021] Figure 5 This is a schematic diagram of the built-in continuous mold structure;

[0022] Figure 6 This is a schematic diagram of the structure in which the copper strip is suspended in the built-in strip mold;

[0023] Figure 7 This is a schematic diagram of the structure of the built-in serial installation on the battery.

[0024] In the figure: 1. Copper tandem; 1-1. Connecting ring; 2. Lead layer; 3. Circular cavity; 3-1. Cone cavity; 3-2. Cylindrical cavity; 4. Interconnected pole; 4-1. Welding column; 4-2. Column; 5. Built-in tandem mold; 5-1. Mold body; 5-2. Operating handle; 5-3. Mold cavity; 5-4. Mold column base; A. Structure before welding of built-in tandem and interconnected pole; B. Structure after welding of built-in tandem and interconnected pole. DETAILED DESCRIPTION

[0025] Existing built-in tandems are made of lead and are relatively long. During high-current and high-power discharges, the temperature rise of the lead tandems increases, their resistance increases, and the energy loss of the built-in tandems is relatively severe, directly affecting the discharge capacity of the battery. According to the resistance calculation formula R=pL / S, where R is resistance, p is resistivity, L is length, and S is cross-sectional area, while the length remains unchanged and the cross-sectional area cannot be reduced, the present invention uses low-resistivity copper tandems wrapped in lead to reduce the overall resistivity of the built-in tandems. The built-in tandems are welded together with the central poles so that the copper tandems are completely embedded within the lead layer, thereby reducing the resistance of the built-in tandems, energy loss, and battery voltage drop.

[0026] The present invention will be further described below with reference to the embodiments and accompanying drawings.

[0027] See Figures 1 to 3 A large-capacity single-cell battery built-in row, the built-in row is set to a "concave" shape, with cylindrical ends and a concave connecting piece in the middle, the built-in row includes a copper row 1, a lead layer 2 and a circular cavity 3, the copper row 1 is set to a concave sheet, and connecting rings 1-1 are respectively provided at both ends, the lead layer 2 is wrapped around the outside of the copper row 1, the copper row is made of tin-nickel alloy, wherein the tin content is ≥90%, and the rest is nickel, to ensure the bonding effect of the copper row and the lead layer; the lead layer 2 wrapped on the surface of the connecting ring 1-1 forms the cylinders at the two ends of the built-in row, the circular cavity 3 is set in the cylinders at the two ends of the built-in row, and the circular cavity 3 It includes a truncated cone cavity 3-1 and a cylindrical cavity 3-2 that are connected. The truncated cone cavity 3-1 is arranged at the top of the cylindrical cavity 3-2, and its height is h1 ≥ 6mm to avoid poor welding and ensure sufficient effective current transmission area during large current discharge; the top diameter of the truncated cone cavity 3-1 is larger than the bottom diameter, and the connecting ring 1-1 is located outside the truncated cone cavity 3-1. The copper at the contact point between the connecting ring 1-1 and the truncated cone cavity 3-1 is exposed. The thickness of the lead layer 2 wrapped around the non-welded parts a, b, c and d outside the copper link 1 is ≥ 3mm to avoid a reduction in battery life due to corrosion and manufacturing deviations during use; see Figure 4 , the middle pole 4 is inserted into the circular cavity 3, as shown Figure 4As shown in part A, the height h2 of the cylindrical cavity 3-2 is the same as the height h3 of the column 4-2 of the intermediate pole 4, which facilitates the positioning of the intermediate pole on the built-in parallel pole group and the parallel pole group; the angle θ between the inner wall of the frustum cavity 3-1 and the outer wall of the welding column 4-1 is ≥60°, and the inner diameter φ1 of the cylindrical cavity 3-2 is 0.3mm-0.8mm larger than the diameter φ2 of the column 4-2, thereby ensuring that the lead does not flow during welding and the welding effect of the intermediate pole is achieved, so that the copper parallel pole is completely wrapped inside the lead layer; see Figure 4 In the structure of the middle B part, the welding column 4-1 at the top of the middle connecting pole 4 is welded and melted in the truncated cone cavity 3-1, completely wrapping the exposed copper connecting row in the lead layer, thereby reducing the resistance, energy loss and battery voltage drop of the built-in connecting row during discharge.

[0028] See Figure 5 and Figure 6 A method for preparing a built-in continuous battery of large-capacity single-cell batteries comprises heating a copper continuous battery 1 to 40±5°C, suspending and inverting the copper continuous battery 1 in a built-in continuous battery mold 5, wherein the built-in continuous battery mold 5 comprises a mold body 5-1 and an operating handle 5-2, wherein the operating handle 5-2 is connected to one end of the mold body 5-1, and the mold body 5-1 is provided with a mold cavity 5-3. The mold body 5-1 is located at the bottom of both ends of the mold cavity 5-3 to form a mold column base 5-4. The shape and size of the mold column base 5-4 are the same as the shape and size of the inverted circular cavity 3. Figure 1 、 Figure 3 and Figure 6 The inner diameter φ3 of the connecting rings at both ends of the copper link 1, the diameter φ4 of the exposed copper of the built-in link and the diameter φ5 of the connecting rings of the copper link placed on the mold column seat are the same, ensuring that the thickness of the lead layer 2 of the non-welded parts a, b, c and d after casting is ≥3mm, the copper link 1 is inverted in the mold cavity 5-3, the connecting rings 1-1 at both ends are sleeved on the outer wall of the lower end of the mold column seat 5-4, and the remaining parts are suspended in the mold cavity 5-3, and lead is poured into the mold cavity 5-3, and the height of the lead layer does not exceed the top height of the mold column seat 5-4, forming a built-in link with a lead layer 2 wrapped around the outer layer of the copper link 1 and having the circular cavity 3 at both ends. The built-in link is demoulded to obtain the built-in link, and the copper at the contact position of the truncated cone cavity at both ends of the prepared built-in link and the outer wall of the lower end of the mold column seat 5-4 is exposed. Example 1

[0029] GFM-2000Ah battery built-in continuous production method and welding method

[0030] Use tin-nickel-plated copper connecting rods with a thickness of 3mm and an inner diameter of 28mm for the circular rings at both ends. The diameter of the contact point between the truncated cone at the bottom of the mold column seat of the built-in connecting rod mold and the copper connecting rod is 28mm. Heat the copper connecting rod to 40±5℃ and place it inside the built-in connecting rod mold. Position the copper connecting rod in the air in the mold cavity and pour lead liquid into the mold cavity. After the production is completed, the lead part wrapped around the outside of the copper connecting rod has a wall thickness of 3.5mm (excluding the exposed copper at the contact point between the mold column seat and the connecting ring); refer to Figure 7 The cavities at both ends of the built-in connecting strip are put on the "positive-positive" middle connecting pole (3 each) and "negative-negative" middle connecting pole (3 each) of the two parallel electrode groups of GFM-2000Ah battery. The molten lead of the welding column on the upper part of the middle connecting pole contacts the molten lead at the conical cavity of the built-in connecting strip and fills the circular cavity of the built-in connecting strip. The exposed part of the copper connecting strip is also completely sealed inside the lead.

[0031] The discharge performance of a built-in battery pack having copper busbars disposed therein (Example 1) of the present invention and a built-in battery pack made only of lead and not having copper busbars disposed therein (its specifications are the same as those of the built-in busbars of the present invention, and its lead thickness is equivalent to the total thickness of the copper and lead of the present invention) were tested respectively. The test results are shown in Tables 1 and 2 (GFM-2000Ah).

[0032] Table 1 Discharge performance parameters of built-in busbars (without copper busbars)

[0033]

[0034] Table 2 Discharge performance parameters of built-in busbars (built-in copper busbars)

[0035]

[0036] As can be seen from Table 1 and Table 2, the voltage drop tends to rise with the increase of discharge current, which has a particularly serious impact on the 1h rate discharge performance. The greater the high current discharge current, the more obvious the impact on discharge performance and the temperature rise of the battery pack. By comparing Table 1 and Table 2, the voltage drop of the battery with built-in battery pack (built-in copper battery pack) is reduced by about 60% compared with the built-in battery pack (no copper battery pack), the temperature rise of the 1h rate battery pack is reduced by about 36%, and the 10h rate, 3h rate and 1h rate capacities of the battery are increased by about 0.5%, 1.7% and 6.8% respectively.

Claims

1. A method for preparing a large-capacity single-cell battery in a built-in row, characterized by: The built-in connecting strip is configured as a "concave" shape, with cylinders at both ends and a concave connecting piece in the middle. The built-in connecting strip comprises a copper connecting strip (1), a lead layer (2) and a circular cavity (3). The copper connecting strip (1) is configured as a concave sheet, with connecting rings (1-1) provided at both ends. The lead layer (2) is wrapped around the outside of the copper connecting strip (1), and the lead layer (2) wrapped around the surface of the connecting ring (1-1) forms the cylinders at both ends of the built-in connecting strip. The circular cavity (3) is provided in the cylinders at both ends of the built-in connecting strip. The circular cavity (3) comprises a truncated cone cavity (3-1) and a cylindrical cavity (3-2) which are connected to each other. The truncated cone cavity (3-1) is arranged at the top end of the cylindrical cavity (3-2). The top diameter of the truncated cone cavity (3-1) is larger than the bottom diameter. The connecting ring (1-1) is located outside the truncated cone cavity (3-1). The middle pole (4) is inserted into the circular cavity (3). The welding column (4-1) at the top end of the middle pole (4) is welded into the truncated cone cavity (3-1), and the exposed portion of the copper connecting row is completely wrapped in the lead layer. The thickness of the lead layer (2) wrapped around the non-welded parts (a), (b), (c) and (d) of the copper connecting bar (1) is ≥3 mm; the preparation method comprises heating the copper connecting bar (1) to 40±5°C, hanging it upside down in a built-in connecting bar mold (5), pouring lead into the built-in connecting bar mold (5) to form a built-in connecting bar with the lead layer (2) wrapped around the outer layer of the copper connecting bar (1) and having the circular cavities (3) at both ends, and demoulding to obtain the built-in connecting bar; The built-in continuous row mold (5) includes a mold body (5-1) and an operating handle (5-2), wherein the operating handle (5-2) is connected to one end of the mold body (5-1), and a mold cavity (5-3) is provided on the mold body (5-1). The mold body (5-1) located at the bottom of both ends of the mold cavity (5-3) forms a mold column base (5-4), and the shape and size of the mold column base (5-4) are the same as the shape and size of the inverted circular cavity (3). The copper continuous row (1) is inverted in the mold cavity (5-3), and the connecting rings (1-1) at both ends are sleeved on the outer wall of the lower end of the mold column base (5-4), and the rest of the copper continuous row (1) is suspended in the mold cavity (5-3). Lead is poured into the mold cavity (5-3), and the height of the lead layer does not exceed the height of the top of the mold column base (5-4).

2. The method for preparing a large-capacity single-cell battery in a continuous row according to claim 1, characterized in that: The height of the truncated cone cavity (3-1) is h1≥6mm.

3. The method for preparing a large-capacity single-cell battery in a continuous row according to claim 2, characterized in that: The height h2 of the cylindrical cavity (3-2) is the same as the height h3 of the column (4-2) of the middle pole (4).

4. The method for preparing a large-capacity single-cell battery in a continuous row according to claim 3, characterized in that: The inner diameter φ1 of the cylindrical cavity (3-2) is 0.3 mm to 0.8 mm larger than the diameter φ2 of the column (4-2).

5. The method for preparing a large-capacity single-unit battery in a continuous row according to claim 4, characterized in that: The included angle θ between the inner wall of the truncated cone cavity (3-1) and the outer wall of the welding column (4-1) is ≥60°.

6. The method for preparing a large-capacity single-unit battery in a continuous row according to claim 5, characterized in that: The copper busbar is plated with a tin-nickel alloy, wherein the tin content is ≥90% and the remainder is nickel.

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