A secondary battery

Abstract

The present invention discloses a secondary battery and a preparation method, comprising: a plate group formed by a positive electrode, a negative electrode and a separator, wherein the positive electrode ear and the negative electrode ear are arranged in opposite directions; an upper current collecting plate and a lower current collecting plate, wherein the upper current collecting plate and the lower current collecting plate are both provided with a plurality of U-shaped through grooves, wherein the positive electrode ear is closely attached to the inner side of the upper current collecting plate, and the negative electrode ear is closely attached to the inner side of the lower current collecting plate; a first space for accommodating solder is formed between the upper current collecting plate and the plate group; and a second space for accommodating solder is formed between the lower current collecting plate and the plate group. The present invention provides a plurality of U-shaped through grooves on both the upper current collecting plate and the lower current collecting plate, and adopts a wire-filling welding process to perform welding in the U-shaped through grooves, so as to realize a firm connection between the positive electrode ear and the negative electrode ear of the battery pack and the upper current collecting plate and the lower current collecting plate, respectively.

Description

Technical Field

[0001] The invention relates to a battery structure, in particular to a secondary battery, and belongs to the technical field of storage batteries. Background Art

[0002] A battery is a device that converts chemical energy into electrical energy. It is widely used in various power storage and supply scenarios, such as household batteries, car batteries, industrial batteries, etc. The battery is composed of multiple positive and negative electrodes stacked together. The connection structure between the positive and negative electrodes inside needs to remain stable and reliable to ensure the performance and life of the battery. The battery collector is the upper and lower guide components of the battery, and can fix and protect the positive and negative electrodes inside the battery.

[0003] In the conventional battery collector plate structure, welding is usually used to fix the positive and negative electrodes;

[0004] During welding, it is usually necessary to sandwich steel bars between the positive and negative electrodes and the current collecting plate for welding. The high temperature required for welding causes the diaphragm to melt easily, damaging the integrity of the diaphragm. The welding efficiency is low and the conductivity after welding is unstable. Summary of the invention

[0005] The object of the present invention is to provide a secondary battery to solve the technical problems existing in the prior art and at least provide a beneficial choice.

[0006] The technical solution of the present invention is implemented as follows: a secondary battery comprises: an electrode group formed by a positive electrode, a negative electrode and a separator, wherein the positive electrode ear and the negative electrode ear are arranged in opposite directions; an upper current collecting plate and a lower current collecting plate, wherein the upper current collecting plate and the lower current collecting plate are both provided with a plurality of U-shaped through grooves, wherein the positive electrode ear is closely attached to the inner side of the upper current collecting plate, and the negative electrode ear is closely attached to the inner side of the lower current collecting plate;

[0007] A first space for accommodating solder is formed between the upper current collecting plate and the electrode group;

[0008] A second space for accommodating solder is formed between the lower current collecting plate and the electrode group.

[0009] Furthermore, the U-shaped through grooves are arranged at equal intervals on the upper current collecting plate and the lower current collecting plate, and the opening directions of two adjacent U-shaped through grooves are opposite.

[0010] Furthermore, the upper current collecting plate and the lower current collecting plate are each provided with four U-shaped through grooves.

[0011] Furthermore, both sides of the upper current collecting plate and the lower current collecting plate are integrally formed with bent fixing portions, which are used to fix the positive electrode ear and the negative electrode ear respectively.

[0012] Furthermore, the top end of the positive electrode ear is fixed to the inner side of the upper current collecting plate by welding.

[0013] Furthermore, the top end of the negative electrode ear portion is fixed to the inner side of the lower current collecting plate by welding.

[0014] The present invention also provides a method for preparing a secondary battery, comprising the following steps:

[0015] (1) A plurality of U-shaped through grooves are respectively provided on the upper current collecting plate and the lower current collecting plate;

[0016] (2) The positive electrode ear is closely attached to the inner side of the upper current collecting plate, and the negative electrode ear is closely attached to the inner side of the lower current collecting plate; a first space for accommodating solder is formed between the upper current collecting plate and the electrode group, and a second space for accommodating solder is formed between the lower current collecting plate and the electrode group;

[0017] (3) Both sides of the upper current collecting plate and the lower current collecting plate are integrally formed with bent fixing parts, which are used to fix the positive electrode ear and the negative electrode ear, respectively. The wire feeding welding process is used to weld in the U-shaped through groove to achieve a firm connection between the positive electrode ear and the negative electrode ear of the battery pack and the upper current collecting plate and the lower current collecting plate.

[0018] In one embodiment, the filler wire welding uses a nickel alloy welding wire including the following components: Cr 8-12wt%, B 0.001-0.008wt%, Si 0.02-0.08wt%, C 0.04-0.1wt%, P 10.6-12.5%wt%, and the balance is Ni.

[0019] In one embodiment, the melting point of the nickel alloy welding wire is 300-500°C.

[0020] In one embodiment, the inclination angle of the welding wire is controlled to be 5-50°, preferably 30-40°, to prevent the electrode plate and the diaphragm from penetrating during welding, thereby causing a short circuit between the positive and negative electrodes.

[0021] Specifically, welding processes such as laser and argon arc welding are used.

[0022] The embodiment of the present invention has the following advantages due to the adoption of the above technical solution:

[0023] The present invention provides a plurality of U-shaped through grooves on both the upper current collecting plate and the lower current collecting plate, and adopts a wire-filling welding process to perform welding in the U-shaped through grooves, so as to realize a firm connection between the positive pole ear portion and the negative pole ear portion of the battery pack and the upper current collecting plate and the lower current collecting plate respectively. This can not only effectively prevent loosening or breakage between the positive and negative poles, but also improve the stability and reliability of the battery pack. By adopting a low-melting-point nickel alloy welding wire, the welding temperature can be reduced to 300-500°. The lower welding temperature helps to reduce the influence of heat on the battery pack, thereby reducing the risk of possible degradation of battery performance. The conductivity after welding is relatively stable and reliable, which is conducive to the connection (series or parallel) of adjacent battery cells.

[0024] The above summary is for illustrative purposes only and is not intended to be limiting in any way. In addition to the illustrative aspects, embodiments and features described above, further aspects, embodiments and features of the present invention will be readily apparent by reference to the accompanying drawings and the following detailed description. BRIEF DESCRIPTION OF THE DRAWINGS

[0025] In order to more clearly illustrate the embodiments of the present application or the technical solutions in the prior art, the drawings required for use in the embodiments or the description of the prior art will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present application. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0026] Figure 1 It is a structural schematic diagram of an embodiment of the present invention;

[0027] Figure 2 for Figure 1 A schematic diagram of the split structure of the embodiment shown;

[0028] Figure 3 for Figure 1 A schematic structural diagram of the upper current collecting plate in the illustrated embodiment;

[0029] Figure 4 for Figure 1 A schematic diagram of the structure of the positive electrode in the embodiment shown;

[0030] Figure 5 This is a side view of the upper / lower current collecting plates and the positive / negative electrodes after being assembled in this embodiment;

[0031] Figure 6 for Figure 5 A partial enlarged schematic diagram of

[0032] Figure 7 This is a physical picture of the welding between the top of the positive electrode ear and the inner side of the upper current collector;

[0033] Figure numerals: 11, upper current collecting plate; 111, U-shaped through groove; 112, bent fixing portion; 12, lower current collecting plate; 13, positive electrode; 131, positive electrode sheet; 132, positive electrode ear; 14, negative electrode; 141, negative electrode sheet; 142, negative electrode ear; 15, separator. DETAILED DESCRIPTION

[0034] In the following, only some exemplary embodiments are briefly described. As those skilled in the art will appreciate, the described embodiments may be modified in various ways without departing from the spirit or scope of the present invention. Therefore, the drawings and descriptions are considered to be exemplary and non-restrictive in nature.

[0035] The embodiments of the present invention are described in detail below with reference to the accompanying drawings.

[0036] Example 1

[0037] like Figure 1-6 As shown, a secondary battery comprises:

[0038] The electrode group is formed by the positive electrode 13, the negative electrode 14 and the separator 15, and the positive electrode ear portion 132 and the negative electrode ear portion 142 are arranged in opposite directions;

[0039] The upper current collecting plate 11 and the lower current collecting plate 12 are both provided with four U-shaped through slots 111, the positive pole ear 132 is closely attached to the inner side of the upper current collecting plate 11, and the negative pole ear 142 is closely attached to the inner side of the lower current collecting plate 12;

[0040] A first space for accommodating solder is formed between the upper current collecting plate 11 and the electrode group;

[0041] A second space for accommodating solder is formed between the lower current collecting plate 12 and the electrode group.

[0042] In one embodiment, the U-shaped through grooves 111 are arranged at equal intervals on the upper current collecting plate 11 and the lower current collecting plate 12 , and the opening directions of two adjacent U-shaped through grooves 111 are opposite.

[0043] In one embodiment, both sides of the upper current collecting plate 11 and the lower current collecting plate 12 are integrally formed with bent fixing portions 112 for fixing the positive electrode ear portion 132 and the negative electrode ear portion 142 respectively.

[0044] In one embodiment, the top end of the positive electrode ear 132 is fixed to the inner side of the upper current collecting plate 11 by welding.

[0045] In one embodiment, the top end of the negative electrode ear portion 142 is fixed to the inner side of the lower current collecting plate 12 by welding.

[0046] Example 2

[0047] The present invention provides a method for preparing a secondary battery, comprising the following steps:

[0048] (1) A plurality of U-shaped through grooves are respectively provided on the upper current collecting plate and the lower current collecting plate;

[0049] (2) The positive electrode ear is closely attached to the inner side of the upper current collecting plate, and the negative electrode ear is closely attached to the inner side of the lower current collecting plate; a first space for accommodating solder is formed between the upper current collecting plate and the electrode group, and a second space for accommodating solder is formed between the lower current collecting plate and the electrode group;

[0050] (3) Both sides of the upper current collecting plate and the lower current collecting plate are integrally formed with bent fixing parts, which are used to fix the positive electrode ear and the negative electrode ear respectively. The wire-filling welding process is used to weld them in the U-shaped through groove to achieve a firm connection between the positive electrode ear and the negative electrode ear of the battery pack and the upper current collecting plate and the lower current collecting plate.

[0051] In one embodiment, the solder is a nickel alloy welding wire including the following components: Cr 8-12wt%, B 0.001-0.008wt%, Si 0.02-0.08wt%, C 0.04-0.1wt%, P 10.6-12.5%wt, and the balance is Ni.

[0052] In one embodiment, the melting point of the nickel alloy welding wire is 300-500°C.

[0053] In one embodiment, a filler wire welding process is used for welding, and the inclination angle of the welding wire is controlled to be 5-50°, preferably 30-40°.

[0054] When the present invention is working: the upper current collecting plate 11 and the lower current collecting plate 12 are both provided with a U-shaped through groove 111, and a wire-filling welding process is adopted to perform welding in the U-shaped through groove to realize a firm connection between the positive pole ear and the negative pole ear of the battery pack and the upper current collecting plate and the lower current collecting plate, which can not only effectively prevent the loosening or breakage between the positive and negative poles, but also improve the stability and reliability of the battery pack. The use of a low-melting-point nickel alloy welding wire can reduce the welding temperature, and only a welding temperature of 300-500° is required. The lower welding temperature helps to reduce the influence of heat on the battery pack, thereby reducing the risk of possibly causing a decrease in battery performance. The conductivity after welding is relatively stable and reliable. Figure 7 This is a physical picture of the welding between the top of the positive electrode ear and the inner side of the upper current collecting plate.

[0055] The above is only a specific embodiment of the present invention, but the protection scope of the present invention is not limited thereto. Any person skilled in the art can easily think of various changes or substitutions within the technical scope disclosed by the present invention, which should be included in the protection scope of the present invention. Therefore, the protection scope of the present invention should be based on the protection scope of the claims.

Claims

1. A secondary battery, characterized in that: include: An electrode group formed by a positive electrode (13), a negative electrode (14) and a separator (15), wherein the positive electrode ear portion (132) and the negative electrode ear portion (142) are arranged in opposite directions; An upper current collecting plate (11) and a lower current collecting plate (12), wherein the upper current collecting plate (11) and the lower current collecting plate (12) are both provided with a plurality of U-shaped through slots (111), the positive electrode ear portion (132) is tightly attached to the inner side of the upper current collecting plate (11), and the negative electrode ear portion (142) is tightly attached to the inner side of the lower current collecting plate (12); A first space for accommodating solder is formed between the upper current collecting plate (11) and the electrode group; A second space for accommodating solder is formed between the lower current collecting plate (12) and the electrode group; The top end of the positive electrode ear portion (132) is fixed to the inner side of the upper current collecting plate (11) by welding; The top end of the negative electrode ear portion (142) is fixed to the inner side of the lower current collecting plate (12) by welding; The welding method is wire feeding welding process, and welding is carried out in a U-shaped through groove; Both sides of the upper current collecting plate (11) and the lower current collecting plate (12) are integrally formed with bent fixing portions (112), which are used to fix the positive electrode ear portion (132) and the negative electrode ear portion (142), respectively.

2. A secondary battery according to claim 1, characterized in that: The U-shaped through grooves (111) are arranged at equal intervals on the upper current collecting plate (11) and the lower current collecting plate (12), and the opening directions of two adjacent U-shaped through grooves (111) are opposite.

3. A secondary battery according to claim 1 or 2, characterized in that: The upper current collecting plate (11) and the lower current collecting plate (12) are both provided with four U-shaped through grooves (111).

4. A method for preparing a secondary battery, characterized in that: The following steps are involved: A plurality of U-shaped through grooves are respectively provided on the upper current collecting plate and the lower current collecting plate; The positive electrode ear is closely attached to the inner side of the upper current collecting plate, and the negative electrode ear is closely attached to the inner side of the lower current collecting plate; a first space for accommodating solder is formed between the upper current collecting plate and the electrode group, and a second space for accommodating solder is formed between the lower current collecting plate and the electrode group; Both sides of the upper collecting plate and the lower collecting plate are integrally formed with bent fixing parts, which are used to fix the positive pole ear and the negative pole ear respectively. The wire feeding welding process is adopted to weld in the U-shaped through groove to achieve a firm connection between the positive pole ear, the negative pole ear of the battery pack and the upper collecting plate and the lower collecting plate.

5. A method for preparing a secondary battery according to claim 4, characterized in that: The filler wire welding adopts nickel alloy welding wire, including the following components: Cr 8-12wt%, B 0.001-0.008wt%, Si 0.02-0.08wt%, C 0.04-0.1wt%, P10.6-12.5%wt, and the balance is Ni.

6. A method for preparing a secondary battery according to claim 4 or 5, characterized in that: The melting point of nickel alloy welding wire is 300-500℃.

7. A method for preparing a secondary battery according to claim 4 or 5, characterized in that: The inclination angle of the welding wire is controlled to be 5-50°.

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