Battery cell and nickel-metal hydride battery

Abstract

The utility model discloses a battery cell and a nickel-metal hydride battery. The battery cell comprises a positive plate, a negative plate and a diaphragm, the diaphragm is arranged between the positive plate and the negative plate. The positive plate comprises a positive material area and a positive blank area, and the positive blank area is connected with a positive tab belt. The negative plate comprises a negative electrode material area containing a negative electrode active material, the inner side edge of the positive electrode tab belt is a first edge, and the edge, close to the positive electrode tab belt, of the negative electrode material area is a second edge; and the negative plate is downwards staggered along the direction far away from the positive pole lug belt, so that the second edge and the first edge are arranged at an interval. According to the utility model, the second edge and the first edge are arranged at an interval, so that one side, close to the positive pole lug belt, of the negative pole piece is far away from the positive pole lug belt in the height direction of the battery cell, sharp edges or burrs on the positive pole lug belt can be prevented from puncturing the diaphragm to be in contact with the negative pole piece, the contact short circuit is avoided, and the safety and the reliability of the battery are improved.

Description

TECHNICAL FIELD

[0001] The utility model relates to a battery field especially relates to a kind of electric core and nickel-hydrogen battery. BACKGROUND

[0002] In the production process of nickel-hydrogen battery, first, the negative current collector is welded to the negative plate, and the positive current collector is welded with the positive nickel strip, then the positive plate, the negative plate and the diaphragm are tightly wound into a cylindrical electrode group. Subsequently, the electrode group is placed in a steel shell, and the negative current collector is fixed at the bottom of the steel shell by spot welding process. Finally, through a series of processes such as rolling groove, coating, alkali injection, spot welding positive cap and sealing, the battery is completed. In the existing design, the coating area of the positive and negative electrodes is usually designed in a facing position to ensure that the battery can operate efficiently and stably. However, during the winding process, sharp edges or burrs may exist on the positive nickel strip, which can easily pierce the diaphragm between the positive plate and the negative plate, causing a short circuit between the positive and negative electrodes, affecting the safety and reliability of the battery. SUMMARY

[0003] The utility model embodiment provides a kind of electric core and nickel-hydrogen battery, to solve the problem that positive nickel strip easily pierces diaphragm, achieve the effect of improving the safety and reliability of battery.

[0004] Specifically, the utility model provides an electric core, comprising a positive plate, a negative plate and a diaphragm; the diaphragm is arranged between the positive plate and the negative plate;

[0005] The positive plate comprises a positive material area containing positive active material and a positive blank area not containing positive active material; the positive blank area is located at the edge of the positive plate;

[0006] A positive tab belt is connected to the positive blank area, and a gap is left between the positive tab belt and the positive material area;

[0007] The negative plate comprises a negative material area containing negative active material;

[0008] Wherein, the inner edge of the positive tab belt is a first edge, and the edge of the negative material area close to the positive tab belt is a second edge; in the direction away from the positive tab belt, the negative plate is misaligned downward, so that the second edge is spaced apart from the first edge.

[0009] Optionally, the distance L between the second edge and the first edge is 1.5-2.5mm.

[0010] Optionally, the edge of the positive material area close to the first edge is a third edge, and the distance L1 between the third edge and the second edge is 0.5-1mm.

[0011] Optionally, the ratio between L1 and the height L2 of the positive material area is 1:(60-500).

[0012] Optionally, the ratio between the height L3 of the positive tab and the height L2 of the positive material area is 1:(10-100).

[0013] Optionally, the negative tab further comprises a negative blank area without negative active material, which is distributed at the edge of the negative tab away from the positive tab or close to the positive tab.

[0014] Optionally, the ratio between the height L4 of the negative blank area and the height of the negative material area is 1:(20-160).

[0015] Optionally, the positive tab is a nickel sheet or a nickel-plated steel strip.

[0016] The utility model further provides a nickel hydrogen battery, including shell and the electric core as any above described, the electric core sets in the shell.

[0017] Optionally, the negative tab is connected with a negative current collector, and the negative current collector is connected with the shell.

[0018] The utility model has the advantages of:

[0019] In the electric core and nickel hydrogen battery, the second edge is arranged apart from the first edge, so that the side of the negative tab close to the positive tab is away from the positive tab in the height direction of the electric core, the sharp edge or burr on the positive tab can be prevented from piercing the diaphragm and contacting the negative tab, the contact short circuit is avoided, and the safety and reliability of the battery are improved. BRIEF DESCRIPTION OF DRAWINGS

[0020] In order to more clearly illustrate the technical scheme of the embodiments of the utility model, the drawings needed to be used in the description of the embodiments of the utility model will be briefly introduced, and obviously, the drawings in the following description are only some embodiments of the utility model, and for those skilled in the art, other drawings can be obtained according to these drawings without creative labor.

[0021] Figure 1 is the schematic position relation diagram of the positive tab and the negative tab in an embodiment of the utility model;

[0022] Figure 2 is the schematic sectional view of the nickel hydrogen battery in an embodiment of the utility model.

[0023] In the figure: 100, positive electrode sheet, 110, positive electrode material area, 120, positive electrode blank area, 121, third edge, 200, negative electrode sheet, 201, second edge, 210, negative electrode material area, 220, negative electrode blank area, 300, separator, 410, positive electrode tab belt, 411, first edge, 420, negative electrode current collector, 500, shell, 510, shell body, 520, cap, 530, insulating piece;

[0024] L, distance between the first edge and the second edge, L1, distance between the second edge and the third edge, L2, height of the positive electrode material area, L3, height of the positive electrode tab belt, L4, height of the negative electrode blank area. DETAILED DESCRIPTION

[0025] In order to make the technical problems, technical schemes and beneficial effects solved by the utility model clearer and more apparent, the utility model will be further described in detail below in combination with the drawings and examples. It should be understood that the specific examples described herein are only used to explain the utility model and not to limit the utility model.

[0026] In the description of the utility model, it should be understood that the orientation or position relationship indicated by the terms "longitudinal", "radial", "length", "height", "thickness", "upper", "lower", "front", "rear", "left", "right", "vertical", "horizontal", "top", "bottom", "inner", "outer" and the like is the orientation or position relationship based on the orientation or position relationship shown in the drawings, which is only for the convenience of describing the utility model and simplifying the description, and does not indicate or imply that the devices or elements referred to must have a particular orientation, be constructed and operated in a particular orientation, and therefore cannot be understood as a limitation on the utility model. In the description of the utility model, unless otherwise specified, the meaning of "a plurality of" is two or more.

[0027] In the description of the utility model, it should be noted that, unless otherwise specified and limited, the terms "mounting", "connection", "connection" should be understood broadly, for example, it can be fixedly connected, or it can be detachably connected, or integrally connected; it can be mechanically connected, or it can be electrically connected; it can be directly connected, or it can be indirectly connected through an intermediate medium; it can be the communication inside two elements. For ordinary skilled in the art, the specific meaning of the above terms in the utility model can be understood according to the specific circumstances.

[0028] Figure 1 is a schematic position relationship diagram of the positive electrode sheet and the negative electrode sheet in an embodiment of the utility model, as shown in Figure 1 , and referring to Figure 2The utility model embodiment provides a kind of electric core, including positive sheet 100, negative sheet 200 and diaphragm 300;The diaphragm 300 is arranged between the positive sheet 100 and the negative sheet 200.The positive sheet 100 includes the positive blank area 120 of containing positive active material positive material area 110 and not containing positive active material;The positive blank area 120 is located at the edge of the positive sheet 100.The positive blank area 120 is connected with positive tab band 410, and the gap is left between positive tab band 410 and positive material area 110.The negative sheet 200 includes containing negative active material negative material area 210.

[0029] Wherein, the inner side edge of the positive tab band 410 is first edge 411, and the edge of the negative material area 210 close to the positive tab band 410 is second edge 201;In the direction away from the positive tab band 410, the negative sheet 200 is misaligned downward, to make the second edge 201 and the first edge 411 interval arrangement.

[0030] In the utility model embodiment, since the second edge 201 and the first edge 411 interval arrangement, make the side of negative sheet 200 close to the positive tab band 410 in the direction of height of electric core away from the positive tab band 410, the sharp edge or burr on the positive tab band 410 can be avoided to pierce diaphragm 300 and negative sheet 200 contact, to avoid contact short circuit, improve the safety and reliability of battery.

[0031] Specifically, the distance L between the second edge 201 and the first edge 411 is 1.5~2.5mm.In this size range, the side of negative sheet 200 close to the positive tab band 410 and the positive tab band 410 have greater interval in the direction of height of electric core, to avoid the sharp edge or burr on the positive tab band 410 to pierce diaphragm 300 and negative sheet 200 contact.

[0032] In an embodiment of the utility model, the positive pole lug strip 410 is a nickel sheet or a nickel-plated steel strip. The base material of the positive pole sheet is foamed nickel, the lower part of the foamed nickel is filled with positive pole active material, and the upper part not filled with positive pole active material is a positive pole blank area 120. The positive pole blank area 120 is not filled with positive pole active material and is only used for welding the positive pole lug strip 410 to avoid interference of the positive pole active material with the welding of the positive pole lug strip 410 and the positive pole material area 110, so that the accuracy and stability of the welding process can be effectively improved, thereby enhancing the overall performance and safety of the battery. The edge of the positive pole material area 110 close to the first edge 411 is a third edge 121, the third edge 121 is located between the second edge 201 and the first edge 411, and the distance L1 between the third edge 121 and the second edge 201 is 0.5-1 mm. If L1 is too small, the positive pole sheet 100 and the negative pole sheet 200 are misaligned, and in the process of using the battery, for example, when the battery is subjected to external forces such as vibration and extrusion, the relative position of the positive pole lug strip 410 may be slightly deviated, which may cause the positive pole lug strip 410 to approach the negative pole sheet 200, and it is difficult to avoid that the positive pole lug strip 410 pierces the diaphragm 300 and contacts the negative pole sheet 200. If L1 is too large, the positive pole sheet 100 and the negative pole sheet 200 are misaligned, which reduces the effective reaction area of the battery, reduces the energy density of the battery, reduces the energy stored by the battery under the same volume or weight, and affects the endurance of the battery.

[0033] In an embodiment of the utility model, the ratio between L1 and the height L2 of the positive pole material area 110 is 1:(60-500). If the ratio between L1 and the height L2 of the positive pole material area 110 is less than 1 / 500 or greater than 1 / 60, as described for L1 being 0.5-1 mm, it is difficult to avoid that the positive pole lug strip 410 pierces the diaphragm 300 and contacts the negative pole sheet 200, and reduces the effective reaction area of the battery.

[0034] In an embodiment of the utility model, the ratio between the height L3 of the positive pole lug strip 410 and the height L2 of the positive pole material area 110 is 1:(10-100). If the ratio between L3 and L2 is too large, the positive pole lug strip 410 occupies too much space inside the battery, which reduces the energy density of the battery, not only affects the endurance of the battery, but also increases the weight and cost of the battery. Therefore, reasonable control of this ratio is of great significance to optimize the performance of the battery and improve the energy density. If the ratio between L3 and L2 is too small, the height of the positive pole lug strip 410 is relatively narrow, which increases the difficulty of welding the positive pole lug strip 410 and the positive pole sheet 100, thereby affecting the firmness and reliability of the welding, which not only increases the internal resistance of the battery, but also increases the risk of poor contact or fracture in long-term use, thereby affecting the overall performance and safety of the battery.

[0035] In one embodiment of this utility model, the negative electrode sheet 200 further includes a negative electrode blank area 220 without negative electrode active material. The negative electrode blank area 220 is distributed on the edge of the negative electrode sheet 200 away from the positive electrode tab 410 and / or close to the edge of the positive electrode tab 410. The negative electrode material area 210 is at the same height as the positive electrode material area 110. The negative electrode blank area 220 is welded to the negative electrode current collector 420. The setting of the negative electrode blank area 220 can avoid the negative electrode active material in the negative electrode material area 210 from interfering with the welding of the negative electrode blank area 220 and the negative electrode current collector 420, so as to effectively improve the accuracy and stability of the welding process, thereby enhancing the overall performance and safety of the battery.

[0036] Furthermore, the ratio of the height L4 of the negative electrode blank area 220 to the height of the negative electrode material area 210 is 1:(20~160). If the ratio of L4 to the height of the negative electrode material area 210 is too large, the proportion of the negative electrode material area 210 on the negative electrode sheet 200 will be relatively reduced, resulting in a reduction in the negative electrode active material and thus a decrease in the energy density of the battery. If the ratio of L4 to the height of the negative electrode material area 210 is too small, the height of the negative electrode blank area 220 will be relatively narrow, increasing the difficulty and uncertainty in the welding process, and easily leading to weak welding or cold solder joints, thereby affecting the overall performance and safety of the battery.

[0037] This utility model embodiment also provides a nickel-metal hydride battery, including a casing 500 and a cell as described in any of the above embodiments, to have all the effects of a cell; the cell is disposed within the casing 500.

[0038] like Figure 2 As shown, in one embodiment of this utility model, the outer casing 500 includes a housing 510, a cap 520, and an insulating member 530. One end of the housing 510 has an opening, and the cap 520 covers the opening. The insulating member 530 surrounds the cap 520 and is located between the housing 510 and the cap 520, thus providing an insulated connection between them. The positive electrode tab 410 is electrically connected to the cap 520, and the negative electrode current collector 420 is welded to the bottom of the housing 510.

[0039] The above-described embodiments are only used to illustrate the technical solutions of this utility model, and are not intended to limit it. Although this utility model has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of this utility model, and should all be included within the protection scope of this utility model.

Claims

1. An electric cell, characterized by, The battery cell comprises a positive electrode sheet (100), a negative electrode sheet (200), and a separator (300); the separator (300) is arranged between the positive electrode sheet (100) and the negative electrode sheet (200); The positive electrode sheet (100) comprises a positive electrode material area (110) containing a positive electrode active material and a positive electrode blank area (120) not containing the positive electrode active material; the positive electrode blank area (120) is located at the edge of the positive electrode sheet (100); The positive electrode blank area (120) is connected with a positive electrode tab belt (410), and a gap is left between the positive electrode tab belt (410) and the positive electrode material area (110); The negative electrode sheet (200) comprises a negative electrode material area (210) containing a negative electrode active material; The inner edge of the positive electrode tab belt (410) is a first edge (411), and the edge of the negative electrode material area (210) close to the positive electrode tab belt (410) is a second edge (201); in the direction away from the positive electrode tab belt (410), the negative electrode sheet (200) is misaligned downward, so that the second edge (201) is arranged in a spaced manner with the first edge (411).

2. The battery cell according to claim 1, wherein The distance L between the second edge (201) and the first edge (411) is 1.5-2.5 mm.

3. The battery cell according to claim 2, wherein The edge of the positive electrode material area (110) close to the first edge (411) is a third edge (121), and the distance L1 between the third edge (121) and the second edge (201) is 0.5-1 mm.

4. The battery cell according to claim 3, wherein The ratio between L1 and the height L2 of the positive electrode material area (110) is 1:(60-500).

5. The battery cell according to claim 1, wherein The ratio between the height L3 of the positive electrode tab belt (410) and the height L2 of the positive electrode material area (110) is 1:(10-100).

6. The battery cell according to claim 1, wherein The negative electrode sheet (200) further comprises a negative electrode blank area (220) not containing a negative electrode active material, which is distributed at the edge of the negative electrode sheet (200) away from the positive electrode tab belt (410) and / or at the edge of the negative electrode sheet (200) close to the positive electrode tab belt (410).

7. The battery cell according to claim 6, wherein The ratio between the height L4 of the negative electrode blank area (220) and the height of the negative electrode material area (210) is 1:(20-160).

8. The electric cell of claim 1, wherein, The positive electrode tab belt (410) is a nickel sheet or a nickel-plated steel belt.

9. A nickel-hydrogen battery, characterized by, The battery cell comprises a housing (500) and the battery cell according to any one of claims 1-8; the battery cell is arranged in the housing (500).

10. The nickel-hydrogen battery according to claim 9, wherein, The negative electrode sheet (200) is connected with a negative electrode current collector (420), and the negative electrode current collector (420) is connected with the housing (500).

Images