Positive temperature coefficient (PTC) device, guide plate provided with PTC device, and battery pack provided with guide plate

Abstract

The utility model provides a PTC (Positive Temperature Coefficient) device, a guide plate with the PTC device and a battery pack with the guide plate. The PTC device (100) is characterized by comprising a PTC chip (20), an upper pin (10) having one end provided on the upper surface of the PTC chip (20), and a lower conductive layer (30) provided on the lower surface of the PTC chip (20), and the upper pin (10) has a bent shape. The guide plate is characterized in that the plurality of PTC devices are connected and configured on the guide plate, and the upper pins of the PTC devices are connected to the guide plate. The battery pack is characterized in that the battery pack is provided with a plurality of cells and the guide plate, and the lower conductive layer of each of the plurality of PTC devices disposed on the guide plate is connected to one electrode terminal of the corresponding cell.

Description

TECHNICAL FIELD

[0001] The utility model relates to a kind of PTC devices, the guide plate with the PTC device and the battery group with the guide plate. BACKGROUND

[0002] In order to protect the battery pack with multiple batteries from the influence of overcurrent and overtemperature generated in the repeated charging and discharging process, a PTC device is usually used as a circuit protection device to connect each battery. The PTC device usually has a metal conductor or a metal foil attached to the surface and back of the PTC chip body. This PTC device usually has a low resistance, and when overcurrent or overtemperature occurs, it generates heat and increases resistance, thereby blocking the current.

[0003] When multiple PTC devices are used together in a battery pack, one PTC device is usually installed on each battery of the battery pack, i.e., one end of the PTC device is welded to one electrode terminal of the corresponding battery in the battery pack, and the other end of the PTC device is welded to the corresponding part on the guide plate. In this case, it is possible that the welding of the PTC device to the electrode terminal of the battery is poor due to contact and processing errors, etc. Moreover, there will be a gap between the PTC device and the electrode terminal, which is not conducive to welding and may cause poor welding, affecting the performance of the assembled battery pack. In order to weld multiple PTC devices on the guide plate to one electrode terminal of each battery of the battery pack, the welding surface of the battery pack needs to be flush with the upper surface of the support frame of the battery pack, i.e., the upper surface of the support frame of the battery pack needs to be flush with the upper surface of the corresponding electrode terminal of the battery, so that the support frame of the battery pack becomes unable to position and fix each battery in the battery pack vertically, and the battery is prone to vertical movement when vibration occurs. As a result, it is not suitable for use in work places with strong vibration impact. In this case, if the batteries of the battery pack need to be positioned and fixed vertically, additional materials and processes need to be added, resulting in increased cost. Furthermore, since the guide plate covers one entire surface of the battery pack, it is not possible to check whether each battery in the battery pack is properly assembled after assembly, and the guide plate covering the entire surface of the battery pack has the disadvantage of wasting materials, thus affecting the quality of the battery pack and increasing the cost of the battery pack.

[0004] In view of the above problems, it is desirable to develop a PTC device with better structural stability and simpler and more reliable welding operation, a guide plate with the PTC device, and a battery pack with the guide plate. SUMMARY

[0005] The utility model aims at solving the above problems existing in the prior art, and provides a PTC device with excellent structural stability and simple and reliable welding operation, a guide plate with the PTC device, and a battery pack with the guide plate.

[0006] In order to achieve the above object, the inventors have made intensive studies and thus have arrived at the following technical solution.

[0007] (1) A PTC device characterized by comprising a PTC chip, an upper lead provided at one end portion of an upper surface of the PTC chip, and a lower conductive layer provided at a lower surface of the PTC chip, wherein the upper lead is in a bent shape.

[0008] (2) The PTC device according to the above (1), characterized in that the upper lead is in a Z-shaped bent shape.

[0009] (3) The PTC device according to the above (1) or (2), characterized in that the one end portion of the upper lead is an upper conductive layer provided on the upper surface of the PTC chip.

[0010] (4) The PTC device according to the above (1) or (2), characterized in that a central portion of the PTC chip is formed with an opening, and a portion of the lower conductive layer is exposed to the side of the upper lead through the opening of the PTC chip.

[0011] (5) A guide plate characterized by comprising a plurality of the PTC devices according to any one of the above (1) to (4) connected thereto, and the upper lead of each of the PTC devices being connected to the guide plate.

[0012] (6) The guide plate according to the above (5), characterized in that a main body portion of each of the PTC devices other than the upper lead is provided in a groove or a hole of the guide plate.

[0013] (7) A battery pack characterized by comprising a plurality of batteries and the guide plate according to the above (5) or (6), and the lower conductive layer of each of the PTC devices provided on the guide plate being connected to one electrode terminal of a corresponding battery, respectively.

[0014] (8) The battery pack according to the above (7), characterized in that the electrode terminal is a negative electrode terminal or a positive electrode terminal.

[0015] (9) The battery pack according to the above (7) or (8), characterized by comprising a support frame.

[0016] (10) The battery pack according to the above (9), characterized in that a rib is provided on the support frame.

[0017] Effect of the Invention

[0018] This invention provides a PTC device with excellent structural stability and simple and reliable welding operation, a guide plate with the PTC device, and a battery pack with the guide plate. Attached Figure Description

[0019] Figure 1A This is a three-dimensional schematic diagram of an example of a PCT device according to Embodiment 1 of this utility model. Figure 1B yes Figure 1A The diagram shows the split state of the PCT device.

[0020] Figure 2 yes Figure 1A and Figure 1B A variation of the PCT device shown.

[0021] Figure 3A A perspective view of an example of a guide plate with multiple PCT devices connected in Embodiment 2 of this utility model. Figure 3B yes Figure 3A Top view. Figure 3C yes Figure 3A Side view.

[0022] Figure 4A This is a three-dimensional schematic diagram of a battery pack with a guide plate installed according to Embodiment 3 of this utility model. Figure 4B yes Figure 4A An enlarged schematic diagram of the portion shown in the dashed box.

[0023] Figure 5 This is a schematic diagram showing the elastic deformation of the upper pin of the PCT device in the bent shape when the guide plate of Embodiment 2 of this utility model is installed on the battery pack.

[0024] Figure 6A This is a schematic diagram of a comparative example PTC device. Figure 6B yes Figure 6A The diagram shows the split state of the PCT device. Figure 6C It is multiple Figure 6A The diagram shows a PTC device soldered to a board via its respective upper pin. Figure 6D yes Figure 6C The diagram shows a schematic of the guide plate mounted on the battery pack. Detailed Implementation

[0025] The specific embodiments and comparative examples of this utility model will now be described in detail with reference to the accompanying drawings. The described embodiments and comparative examples are merely exemplary and can take many different forms. Furthermore, the drawings disclosed in this specification are, in principle, only schematic illustrations. That is, the dimension ratios in the drawings may not be consistent with the actual dimension ratios, and the dimension ratios may not be consistent between different drawings.

[0026] (Embodiment 1)

[0027] Embodiment 1 relates to a PTC device, characterized in that it comprises a PTC chip, an upper pin arranged at an upper surface of the PTC chip, and a lower conductive layer arranged at a lower surface of the PTC chip, wherein the upper pin is in a bent shape.

[0028] The shape of the PTC chip and the lower conductive layer in the PTC device can be selected according to actual needs, and can be circular, square, etc.

[0029] From the aspects of facilitating application and welding operation, etc., the PTC chip and the lower conductive layer are preferably in a concentric symmetrical shape, for example, concentric circular or concentric symmetrical square.

[0030] In order to facilitate positioning and welding operation, it is preferred that a central part of the PTC chip is formed with an opening, and a part of the lower conductive layer is exposed to the side of the upper pin through the opening of the PTC chip. Moreover, the central part of the lower conductive layer 30 can have a slit with an opening, when the PTC device is used to connect with a battery, the lower conductive layer is directly contacted and welded with one electrode terminal of the battery, the opening of the PTC chip and the slit of the lower conductive layer can facilitate positioning and welding operation, and can improve the welding quality.

[0031] The material of the lower conductive layer can be a nickel sheet, a copper sheet, etc., and is preferably a nickel sheet from the aspects of conductivity, welding reliability, welding process, etc. The thickness of the lower conductive layer can be selected according to actual needs of strength, flexibility or deformability, etc., and can be 0.1 mm to 0.5 mm.

[0032] The thickness of the upper pin can be selected according to actual needs of strength, flexibility or deformability, etc., and can be 0.1 mm to 0.5 mm. The bent shape of the upper pin is not particularly limited as long as it is easy to elastically deform and easy to weld, for example, can be a Z-shaped bent shape, an L-shaped bent shape, an arc-shaped bent shape, etc. However, from the aspects of being easier to elastically deform and easier to weld with the battery pack, the upper pin is preferably in a Z-shaped bent shape. Moreover, the bending amplitude and length of each part of the bent shape can be adjusted according to actual needs.

[0033] The upper pin is usually in a strip shape, and the length dimension and specific shape thereof can be selected according to actual needs of connection requirements. The specific shape thereof can be, for example, a flat long sheet shape or a square strip shape, etc.

[0034] The material of the upper pin is metal, preferably nickel, iron-nickel plating or stainless steel.

[0035] The one end of the upper pin can also be deformed into an upper conductive layer arranged on the upper surface of the PTC chip, that is, the one end of the upper pin is an upper conductive layer arranged on the upper surface of the PTC chip. The shape of the upper conductive layer can be the same as that of the PTC chip. This is more conducive to the positioning and fixing of the PTC device, and is more conducive to welding the PTC device to the guide plate and improving the position accuracy of the PTC device.

[0036] Figure 1A is a perspective view of an example of the PCT device of embodiment 1 of the present application. Figure 1B is Figure 1A is a schematic view of the PCT device shown in Figure 1A and Figure 1B , the PCT device 100 has a PTC chip 20, an upper pin 10 with one end arranged on the upper surface of the PTC chip, and a lower conductive layer 30 arranged on the lower surface of the PTC chip 20, wherein the upper pin 10 is in a Z-shaped bending shape. The central part of the PTC chip 20 is formed with an opening, a part of the lower conductive layer 30 is exposed to the side of the upper pin 10 through the opening of the PTC chip 20, and the central part of the lower conductive layer 30 has a slit with an opening. When the PCT device is used in connection with a battery, the lower conductive layer 30 is in direct contact and welded with one electrode terminal of the battery, and the opening of the PTC chip 20 and the slit of the lower conductive layer 30 help to position and weld, and can improve the welding quality.

[0037] Figure 1A and Figure 1B , the PTC chip and the lower conductive layer are concentric circles, the PTC chip is a circle with an opening in the center, and the lower conductive layer is a circle with a slit in the center, but according to actual needs, the shapes of the PTC chip and the lower conductive layer can also be other shapes such as squares. Figure 1B As shown in , the size of the lower conductive layer can be smaller than that of the PTC chip, and the purpose of this design is to save raw materials of the lower conductive layer and reduce costs, and has little effect on the performance of the entire PTC device.

[0038] Figure 1A Figure 1B shows that the one end of the upper pin in a bending shape is arranged on the upper surface of the PTC device, and Figure 2 isFigure 1A and Figure 1B In a modification of the PTC device shown in Figure 1A and Figure 1B The upper pin shown in Figure 2 Compared with the upper pin shown in

[0039] (Embodiment 2)

[0040] Embodiment 2 relates to a guide plate, characterized in that a plurality of PTC devices as described in Embodiment 1 are connected and arranged on the guide plate, and the upper pin in the PTC device is connected to the guide plate.

[0041] The upper pin in the PTC device can be connected to the guide plate by welding or clamping, but from the stability of the connection, it is preferred to be connected by welding. The guide plate can be provided with a groove or a hole, for example, a semicircular groove or hole, which reserves space for welding between the PTC device and the electrode terminal of the battery, not only having the function of positioning, but also helping to weld, which can improve the welding quality. The width of the guide plate can be designed according to the actual flow needs. It is preferred that the main body part (hereinafter referred to as "the main body part of the PTC device" for short) of the PTC device except the upper pin is arranged in the groove or hole of the guide plate, which positions the main body part of the PTC device, but the main body part of the PTC device cannot be in contact with the guide plate, otherwise the PTC device will be short-circuited and lose its use. The groove or hole is preferably a semicircular groove or hole, because such a setting not only can meet the functions of positioning and helping to weld, but also can make the area of the guide plate relatively small, which can reduce the amount of material, save costs, reduce the weight of the battery pack, and further, when the guide plate is installed to the battery pack, the guide plate will only cover part of the surface of the battery pack, thereby facilitating the inspection of whether each battery in the battery pack is correctly assembled. It should be noted that when the PTC device is welded to the guide plate, the groove or hole on the guide plate can position the main body part of the PTC device. When the lower conductive layer of the PTC device on the guide plate is welded to the surface of one electrode terminal of the battery of the battery pack, the groove or hole on the guide plate can position the welding rod, which can improve the welding quality.

[0042] Figure 3A is a perspective view of an example of the guide plate connected and arranged with a plurality of PTC devices of Embodiment 2 of the utility model. Figure 3B is Figure 3A a top view. Figure 3C isFigure 3A Side view.

[0043] like Figures 3A-C As shown, the main bodies of multiple PTC devices 100 are disposed in grooves or holes 90 on the guide plate 120. The upper pin 10 of one PTC device 100 is connected to the upper pin 10 of other PTC devices through the guide plate 120, thereby connecting multiple PTC devices 100 in parallel. When the lower conductive layers of multiple PTC devices on the guide plate are soldered to an electrode terminal of each battery in the battery pack, the batteries in the battery pack can be connected in parallel. Therefore, such a guide plate is sometimes called a parallel guide plate.

[0044] (Implementation Method 3)

[0045] Embodiment 3 relates to a battery pack, characterized in that it comprises a plurality of batteries and a guide plate as described in Embodiment 2, wherein the lower conductive layer of a plurality of PTC devices disposed on the guide plate is respectively connected to an electrode terminal of a corresponding battery.

[0046] The aforementioned electrode terminals can be either the negative or positive terminals of the battery, depending on the circuit design and functional requirements.

[0047] The aforementioned battery pack utilizes the guide plate described in Embodiment 2. This guide plate can be provided with grooves or holes, such as semi-circular grooves or holes, which provides space for welding between the PTC device and the battery's electrode terminals. This not only serves a positioning function but also facilitates welding and improves welding quality. The width of the guide plate can be designed according to actual current flow requirements. The aforementioned battery pack has a support frame for housing the individual batteries within the pack. The support frame can be provided with raised ribs for vertically positioning and fixing the individual batteries in the pack, preventing them from wobbling.

[0048] Figure 4A This is a three-dimensional schematic diagram of a battery pack with a guide plate installed according to embodiment 3. Figure 4B yes Figure 4A An enlarged schematic diagram of the portion shown in the dashed box.

[0049] like Figure 4A and Figure 4B As shown, there is an elastic deformation space 80 between the PTC device 100 and the guide plate 120, and the upper surface of the battery pack support frame 110 does not need to be flush with the upper surface of the electrode terminals of the battery 95. Therefore, the battery pack support frame can have ribs 60 to position and fix the battery 95 vertically to prevent the battery 95 in the battery pack from shaking vertically when vibrating.

[0050] like Figure 4AAs shown in FIG. 1, the guide plate 120 only covers a part of the surface of the battery pack, so it is convenient to check whether each battery in the battery pack is assembled correctly. When welding the plurality of PTC devices 100 of the guide plate 120 to the surface of one electrode terminal of the corresponding battery 95 in the battery pack respectively, the semicircular grooves or holes on the guide plate can position the welding, which can improve the welding quality.

[0051] Figure 5 is a schematic diagram of the elastically deformable upper lead of the PTC device when the guide plate of the embodiment 2 of the present application is installed on the battery pack. As shown in FIG. 2, the PTC device has an upper lead with a bent shape, which can be elastically deformed during welding, can absorb the processing stress and processing error, and can improve the welding quality and structural stability. When the guide plate is installed on the battery pack, the upper lead with a bent shape forms an elastically deformed space 80 between the guide plate and the surface of the battery, which can make the PTC device fully contact with the surface of one electrode terminal of the battery, thereby improving the welding operability and reliability, and thus improving the welding quality, and when the PTC device is heated and expanded, there is enough buffer space, and it will not fail due to lack of space. Figure 5

[0052] It should be noted that the guide plate can be installed on the negative electrode terminal of each battery of the battery pack, and the guide plate can also be installed on the positive electrode terminal of each battery of the battery pack, and in both cases, the guide plate and the PTC device can have the same structure and configuration.

[0053] In the embodiment 3, the above-mentioned battery can be a primary battery or a secondary battery. The above-mentioned secondary battery is preferably a lithium ion secondary battery, a nickel-hydrogen secondary battery, or various secondary batteries. Moreover, although only cylindrical batteries are shown in the drawings, the batteries can also be square batteries or other shaped batteries.

[0054] According to the above-mentioned embodiments 1-3, the PTC device with an upper lead with a bent shape and the guide plate with the PTC device can absorb the contact and processing error through the upper lead with a bent shape, can make the PTC device fully contact with the surface of one electrode terminal of the battery to improve the welding, and the guide plate with a plurality of PTC devices connects the plurality of PTC devices. In addition, by providing grooves or holes, such as semicircular grooves or holes, on the guide plate for positioning the main body part of the PTC device, not only can the positioning function be met, but also the welding can be facilitated, and the welding quality can be improved.

[0055] (Comparative Example)

[0056] Figure 6A is a schematic diagram of the PTC device of the comparative example.​Figure 6B yes Figure 6A The diagram shows a split state of the PCT device. The PCT device 100 includes a PTC chip 20, an upper pin 10 disposed on the upper surface of the PTC chip 20, and a lower conductive layer 30 disposed on the lower surface of the PTC chip 20. The upper pin 10 is straight and not bent.

[0057] Figure 6C Multiple Figure 6A The diagram shows a PTC device 100 soldered onto a guide plate 120 via its respective upper pin. Figure 6D It shows Figure 6C The diagram shows a schematic of the guide plate mounted on the battery pack.

[0058] like Figure 6D As shown, when a guide plate 120 equipped with multiple PTC devices 100 is covered on the upper surface of the battery pack, the multiple PTC devices 100 are respectively welded to one electrode terminal of each of the multiple batteries 95 arranged side by side in the battery pack, thereby connecting the multiple batteries 95 in parallel.

[0059] In other words, such as Figure 6C As shown, multiple PTC devices 100 are soldered to the guide plate 120 via their respective upper leads, and then as follows: Figure 6D As shown, the guide plate 120 is placed on the upper surface of the battery pack, and then the plurality of PTC devices 100 are respectively soldered to an electrode terminal of the corresponding battery 95.

[0060] In the present comparative example, the PTC device 100 can not be properly attached due to processing errors, resulting in poor welding. Moreover, since the guide plate covers the entire surface of the battery pack, it is not possible to check whether each battery in the battery pack is properly assembled after installation, and the guide plate covering the entire surface of the battery pack has the disadvantage of wasting material, thus affecting the quality of the battery pack and increasing the cost of the battery pack. Furthermore, in order to weld the plurality of PTC devices 100 to the electrode terminals of the corresponding batteries 95 of the battery pack respectively, the welding surface of the battery pack and the PTC device 100 needs to be flush with the upper surface of the support frame 110 of the battery pack, i.e. the upper surface of the support frame 110 of the battery pack needs to be flush with the upper surface of the electrode terminal of each of the plurality of batteries 95, so that the support frame of the battery pack cannot position and fix each battery in the battery pack up and down, and the batteries are prone to move up and down when vibration occurs, resulting in that it is not suitable for use in work places with strong vibration impact. In this case, if the batteries in the battery pack need to be positioned and fixed up and down, additional materials need to be added, resulting in increased cost. Furthermore, the spacing distance between the PTC device and the corresponding electrode terminal of the battery is not conducive to welding, which can result in poor welding and affect the performance of the assembled battery pack.

[0061] The embodiments of the present application have been described in detail above, but the present application is not limited to the above-described specific embodiments. Various modifications or changes can be made by those skilled in the art without departing from the spirit and scope of the present application defined by the claims, and these modified examples and changes are of course within the scope of the present application.

[0062] Industrial applicability

[0063] The present application can provide a PTC device with excellent structural stability and simple and reliable welding operation, a guide plate with the PTC device, and a battery pack with the guide plate.

Claims

1. A PTC device, characterized in that, It comprises a PTC chip, an upper pin disposed on the upper surface of the PTC chip at one end, and a lower conductive layer disposed on the lower surface of the PTC chip, wherein the upper pin is bent.

2. The PTC device according to claim 1, characterized in that, The upper pin has a Z-shaped bend.

3. The PTC device according to claim 1 or 2, characterized in that, One end of the upper pin is an upper conductive layer disposed on the upper surface of the PTC chip.

4. The PTC device according to claim 1 or 2, characterized in that, An opening is formed in the center of the PTC chip, and a portion of the lower conductive layer is exposed to the upper pin side through the opening of the PTC chip.

5. A guide plate, characterized in that, The guide plate is configured with a plurality of PTC devices as described in any one of claims 1 to 4, wherein the upper pins of the PTC devices are connected to the guide plate.

6. The guide plate according to claim 5, characterized in that, The main body portion of the PTC device, excluding the upper pin, is disposed in the groove or hole of the guide plate.

7. A battery pack, characterized in that, It comprises multiple batteries and a guide plate as described in claim 5 or 6, wherein the lower conductive layer of each of the multiple PTC devices disposed on the guide plate is connected to an electrode terminal of the corresponding battery.

8. The battery pack according to claim 7, characterized in that, The electrode terminals are either negative or positive terminals.

9. The battery pack according to claim 7 or 8, characterized in that, The battery pack has a support frame.

10. The battery pack according to claim 9, characterized in that, The support frame is provided with protruding ribs.

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