Battery top cover, battery and battery pack

Abstract

The utility model provides a battery top cover, a battery and a battery pack. The battery top cover comprises a cover body and at least two poles arranged on the cover body, at least one pole is correspondingly provided with the fusing assembly, and the fusing assembly and the corresponding pole have a disconnection state and a connection state; and the piezoresistor is connected between the two pole columns and is connected in series with the fusing assembly. According to the battery pack, the problem that the batteries are easily overcharged due to the consistency of the batteries in the battery pack in the prior art is solved.

Description

TECHNICAL FIELD

[0001] The utility model relates to battery technology field, specifically, relate to a battery top cover, battery and battery package. BACKGROUND

[0002] In the production process of the battery pack, the newly factory battery must be pretreated to ensure the consistency of the battery before being integrated into the module, which aims to avoid overcharge or overdischarge problems caused by the performance difference of single battery. The total capacity of the battery pack depends on the battery with the smallest capacity in the module, which means that when all the batteries in the module try to reach the full charge state, the battery with lower capacity will face the risk of overcharge; conversely, in the discharging process, the battery with higher capacity may not be fully utilized, that is, the phenomenon of premature overdischarge occurs. To solve this problem, battery manufacturers usually use preliminary screening technology to classify batteries by measuring open circuit voltage (OCV), alternating current resistance (ACR) and virtual capacity (i.e. the capacity of the battery under incomplete full charge state). However, this classification method has certain limitations and often cannot accurately match the consistency of the battery, so further grouping is needed during the assembly stage of the battery pack to ensure the capacity consistency of the module and improve the overall performance and prolong the service life of the module.

[0003] Therefore, there is a problem in the prior art that the battery pack is prone to overcharge due to the consistency of the battery. UTILITY MODEL CONTENTS

[0004] The main purpose of the utility model is to provide a battery top cover, battery and battery package to solve the problem that the battery pack is prone to overcharge due to the consistency of the battery in the prior art.

[0005] In order to achieve the above purpose, according to one aspect of the utility model, a battery top cover is provided, which comprises a cover body and at least two pole columns and at least one fuse assembly provided on the cover body, at least one pole column is provided with a fuse assembly, and the fuse assembly and the corresponding pole column have a disconnected state and a conductive state; a pressure sensitive resistor is connected between the two pole columns and in series with the fuse assembly.

[0006] Further, at least a part of the fuse assembly is arranged inside the corresponding pole column.

[0007] Further, the fuse assembly comprises: an insulating part, at least a part of the insulating part is arranged inside the corresponding pole column, and the insulating part has a containing cavity and a connecting opening communicating with the containing cavity; a fuse wire, the fuse wire is arranged in the containing cavity in a state changeable manner, the conductive part of the pole column extends into the containing cavity and has a disconnected state and a conductive state with the fuse wire, and the pressure sensitive resistor is electrically connected with the fuse wire.

[0008] Further, the fuse assembly further comprises a sealing member, the sealing member is arranged in the accommodating cavity, and the sealing member is located at the end of the fuse wire away from the conductive part.

[0009] Further, the battery top cover further comprises a wire, one end of the wire is connected with the pressure-sensitive resistor, the other end of the wire extends into the connecting opening and is connected with the fuse wire through the sealing member.

[0010] Further, the accommodating cavity comprises a vertical segment and a horizontal segment connected in sequence, the fuse wire is arranged in the vertical segment, and the horizontal segment has the connecting opening at the end away from the vertical segment.

[0011] Further, the conductive part extends into the vertical segment and is located at the end of the vertical segment away from the horizontal segment, and the extension direction of the conductive part is the same as the horizontal direction.

[0012] Further, the fuse wire is made of any one of magnesium, lead, tin and antimony.

[0013] Further, the battery top cover further comprises an explosion-proof valve arranged on the cover body, and the pressure-sensitive resistor is arranged on the explosion-proof valve.

[0014] According to another aspect of the utility model, a battery is provided, the battery comprises any one of the above battery top covers.

[0015] According to still another aspect of the utility model, a battery pack is provided, comprising a plurality of batteries, at least one battery having the above battery top cover.

[0016] According to the technical scheme of the utility model, the battery top cover in the application comprises a cover body and at least two pole columns, at least one fuse assembly and a pressure-sensitive resistor arranged on the cover body. The at least one pole column is correspondingly provided with the fuse assembly, and the fuse assembly and the corresponding pole column have a disconnected state and a conductive state; the pressure-sensitive resistor is connected between the two pole columns and is connected in series with the fuse assembly.

[0017] When the battery top cover in the application is used, since the battery top cover has a fuse assembly and a pressure sensitive resistor, and the fuse assembly has an open state and a conducting state, and the pressure sensitive resistor can be connected in parallel with the battery using the battery top cover in the application through the electrical connection with the fuse assembly. When the battery is in the first stage of initial charging, since the current passing through the battery is large, the fuse assembly is fused, at this time the fuse assembly is in the open state with the pole, so the parallel circuit of the pressure sensitive resistor and the battery can be disconnected, and the pressure sensitive resistor cannot work normally, so as to prevent the large charging current from passing through the pressure sensitive resistor, thereby protecting the pressure sensitive resistor. With the continuous charging of the battery, the battery is in the second stage, at this time the charging current is reduced, at this time the fuse assembly is in the conducting state with the pole, and the parallel circuit of the pressure sensitive resistor and the battery can be conducted. With the continuous charging of the battery, when the voltage of a certain battery in the battery pack exceeds the rated voltage of the battery due to overcharging, the pressure sensitive resistor of the battery top cover corresponding to the battery starts to work, and the fully charged battery stops charging, and the uncharged battery continues to charge. That is, in the application, when the battery is fully charged, with the increase of the voltage, the resistance of the pressure sensitive resistor decreases, and the fully charged battery can be short-circuited, thereby protecting the battery from overcharging. BRIEF DESCRIPTION OF DRAWINGS

[0018] The drawings accompanying the specification of the present application form a part thereof, serve to provide further understanding of the present application, and together with the specification explain the application. The use of the same reference numbers in different drawings indicates similar or identical components.

[0019] Figure 1 A structure schematic view of a battery top cover according to one specific embodiment of the present application is shown;

[0020] Figure 2 A cross-sectional view of the battery top cover in Figure 1 is shown;

[0021] Figure 3 A position relationship schematic view of the fuse wire and the conductive part of the battery top cover in Figure 1 when the fuse wire and the conductive part are in the conducting state is shown;

[0022] Figure 4 A position relationship schematic view of the fuse wire and the conductive part of the battery top cover in Figure 1 when the fuse wire and the conductive part are in the open state is shown;

[0023] Figure 5 A connection relationship schematic view of a plurality of batteries in a battery pack in one specific embodiment of the present application is shown.

[0024] Among the above drawings, the following reference signs are included:

[0025] 10, pole; 11, positive pole; 12, negative pole; 13, conductive part; 20, fuse assembly; 21, insulating part; 211, accommodating cavity; 2111, vertical section; 2112, horizontal section; 212, connecting opening; 22, fuse; 23, sealing member; 30, pressure sensitive resistor; 40, cover; 50, wire; 60, explosion-proof valve; 70, battery; 80, liquid injection hole. DETAILED DESCRIPTION

[0026] It should be noted that the embodiments and features in the embodiments of the present application can be combined with each other without conflict. The present application will be described in detail below with reference to the accompanying drawings and in combination with the embodiments.

[0027] It should be noted that, unless otherwise specified, all technical and scientific terms used in the present application have the same meaning as generally understood by those skilled in the art to which the present application belongs.

[0028] In the present application, unless otherwise specified, the orientation words such as "upper, lower, top, bottom" are generally directed to the directions shown in the drawings, or are directed to the vertical, perpendicular or gravity directions of the components themselves; similarly, for the convenience of understanding and description, "inner, outer" refers to the inner and outer relative to the contour of each component itself, but the above orientation words are not used to limit the present application.

[0029] In order to solve the problem that the battery pack is prone to overcharging due to the consistency of the battery in the prior art, the present application provides a battery top cover, a battery and a battery pack.

[0030] Furthermore, as shown in Figure 5 The battery pack in the present application includes a plurality of batteries, and at least one battery has the following battery top cover.

[0031] As shown in Figures 1 to 4 The battery top cover in the present application includes a cover 40 and at least two poles 10, at least one fuse assembly 20 and a pressure sensitive resistor 30 arranged on the cover 40. The at least one pole 10 is provided with the fuse assembly 20, and the fuse assembly 20 and the corresponding pole 10 have a disconnected state and a conductive state; the pressure sensitive resistor 30 is connected between the two poles 10 and is connected in series with the fuse assembly 20. At the same time, the cover 40 is also provided with a liquid injection hole 80. Preferably, the number of poles and fuse assemblies is equal and one-to-one corresponding, that is, each pole is provided with one fuse assembly, at this time, the pressure sensitive resistor 30 is connected between the two fuse assemblies 20, and is connected in parallel with the battery.

[0032] The open state and the conductive state between the fuse assembly and the corresponding pole post are controlled by the current charged into the battery when the battery is charging. For example, when the battery charging current is small, the fuse assembly and the corresponding pole post are in a conductive state, and when the battery charging current is large, the fuse assembly and the corresponding pole post are in an open state. The specific structure of the fuse assembly is not limited in the embodiments of the application, as long as it can have the above functions.

[0033] The working principle of the pressure-sensitive resistor 30 is that when the voltage applied to the pressure-sensitive resistor 30 exceeds a certain value, the resistance value of the pressure-sensitive resistor 30 will rapidly decrease to conduct a large current, thereby protecting the rear-end circuit; when the voltage is lower than the working voltage, the resistance value of the pressure-sensitive resistor 30 is extremely high, which is equivalent to an open circuit, and does not affect the working state of the rear-end circuit.

[0034] In general, in the first stage of initial charging of the battery, a large first current is used for charging, and in the second stage of the end of charging of the battery, a small second current is used for charging. The first stage and the second stage can be divided according to the SOC of the battery, the voltage of the battery, etc. Since the fuse assembly 20 has an open state and a conductive state, and the pressure-sensitive resistor 30 is connected in parallel with the battery of the battery top cover by the electrical connection with the fuse assembly 20. When the battery is in the first stage of initial charging, the current passing through the battery is large, the fuse assembly 20 is fused, at this time the fuse assembly 20 and the pole post 10 are in an open state, so that the parallel circuit of the pressure-sensitive resistor 30 and the battery can be disconnected, and the pressure-sensitive resistor 30 cannot work normally, so as to prevent a large charging current from passing through the pressure-sensitive resistor 30, thereby protecting the pressure-sensitive resistor. As the battery is continuously charged, the battery enters the second stage, at this time the charging current decreases, at this time the fuse assembly 20 and the pole post 10 are in a conductive state, and the parallel circuit of the pressure-sensitive resistor 30 and the battery is turned on. When the battery in the battery pack is overcharged, the voltage of the battery will exceed the rated voltage of the battery, at this time the pressure-sensitive resistor 30 of the battery top cover corresponding to the battery starts to work, and the fully charged battery stops charging, and the uncharged battery continues to charge. That is, in the application, when the battery is fully charged, the resistance value of the pressure-sensitive resistor decreases with the increase of the voltage, so as to control the current passing through the fully charged battery, thereby protecting the battery from overcharging.

[0035] Therefore, when the battery using the battery top cover in the application is charged, the charging current of the battery is large at the beginning, the fuse assembly 20 melts and disconnects the pressure-sensitive resistor 30 from the battery, and when the battery is charged to a certain extent, the charging current of the battery decreases, the fuse assembly 20 cools down again and switches to the conducting state between the fuse assembly 20 and the pole 10, at this time the pressure-sensitive resistor 30 is electrically connected to the pole through the fuse assembly 20, and after the battery is fully charged, the charging voltage rises, at this time the resistance of the pressure-sensitive resistor 30 decreases, resulting in that most of the current passes through the pressure-sensitive resistor 30 and a small amount of current passes through the battery, so that the corresponding battery can be almost stopped charging by the action of the pressure-sensitive resistor 30, thereby avoiding the overcharging of the battery. Therefore, the battery top cover in the application effectively solves the problem that the battery pack in the prior art is prone to overcharging due to the consistency of the battery.

[0036] As shown in Figure 1 and Figure 2 In the application, the battery top cover can have two poles 10 and two fuse assemblies 20, and one of the poles 10 is a positive pole 11 and the other pole 10 is a negative pole 12, one of the fuse assemblies 20 is electrically connected to the positive pole 11, the other fuse assembly 20 is electrically connected to the negative pole 12, and the two fuse assemblies 20 are electrically connected through the pressure-sensitive resistor 30.

[0037] It should be noted that each battery 70 of the battery pack in the application can have the battery top cover of the application. At the same time, when the battery 70 of the battery pack is charged and the consistency of the battery of the battery pack is poor, when the charging current of the battery 70 with low capacity decreases, the fuse assembly 20 and the pole 10 of the battery top cover corresponding to the battery 70 will switch from the disconnected state to the conducting state, and if the battery 70 with low capacity is charged to its set cut-off voltage during the continuation of the charging, at this time the charging voltage is high, the resistance of the pressure-sensitive resistor decreases and controls the current flowing through the battery with low capacity to be extremely small, so that the charging of the battery 70 can be stopped, and for the battery 70 with high capacity, since the cut-off voltage is not reached, the resistance of the parallel pressure-sensitive resistor is large and has no effect on the charging current of the battery with high capacity, so that the battery 70 with high capacity can continue to be charged until the battery with high capacity is fully charged, the resistance of the pressure-sensitive resistor decreases and controls the current flowing through the battery with high capacity to be extremely small, so that the charging of the battery 70 can be stopped, and so on, until the charging is completed. And, as shown in Figure 5As shown, the plurality of batteries 70 of the battery pack can be connected in series, and the fuse assembly 20 corresponding to the battery top cover can be regarded as a switch capable of being opened or closed. That is, in the present application, the capacity difference between the batteries of the battery pack can be regulated by using the pressure-sensitive resistor 30, so that after the battery with low capacity is fully charged, the battery with high capacity can continue to be charged without overcharging, thereby enabling the full play of the capacity of each battery in the battery pack.

[0038] Optionally, at least a part of the fuse assembly 20 is arranged inside the corresponding pole 10. By arranging in this way, the overall structure of the battery top cover can be more compact.

[0039] In one specific embodiment of the present application, as shown in Figure 3 and Figure 4 The fuse assembly 20 includes an insulating part 21 and a fuse wire 22. At least a part of the insulating part 21 is arranged inside the corresponding pole 10, and the insulating part 21 has a receiving cavity 211 and a connecting opening 212 communicating with the receiving cavity 211. The fuse wire 22 is arranged in the receiving cavity 211 in a state-changeable manner. The conductive part 13 of the pole 10 extends into the receiving cavity 211 and has an open state and a conductive state with the fuse wire 22, and the pressure-sensitive resistor 30 is electrically connected with the fuse wire 22. By arranging the insulating part 21, it can be effectively ensured that the pole 10 can only realize conduction or disconnection with the fuse wire 22 through the conductive part 13 extending into the receiving cavity 211. Meanwhile, in the present embodiment, when the battery is charging and in the first stage, the fuse wire 22 melts due to the large charging current, at which time the fuse wire 22 is in the open state with the conductive part 13, and when the battery is in the second stage, the charging current becomes small, at which time the fuse wire 22 cools down, and the fuse wire 22 and the conductive part 13 switch from the open state to the conductive state, so that the pressure-sensitive resistor 30 can work normally. Arranging the fuse wire 22 in the receiving cavity 211 can limit the melted fuse wire 22 to a certain extent through the receiving cavity 211, thereby ensuring the use performance of the battery top cover.

[0040] As can be seen from the above embodiment, in the present application, the fuse wire 22 can protect the pressure-sensitive resistor 30 to a certain extent, that is, during the charging of the battery, the fuse wire 22 can be disconnected to prevent large current from passing through the pressure-sensitive resistor 30, thereby effectively avoiding damage to the pressure-sensitive resistor 30 during charging or discharging of the battery.

[0041] Preferably, as shown in Figure 3As shown, the fuse assembly 20 further comprises a sealing member 23, which is arranged in the accommodating cavity 211 and located at the end of the fuse wire 22 away from the conductive part 13. After the fuse wire 22 is melted, the sealing member 23 can support the melted fuse wire 22, so that the fuse wire 22 can be kept at a preset position after being melted, and then the fuse wire 22 can keep electrically connected with the conductive part 13 of the pole 10 after being cooled. Further preferably, the accommodating cavity 211 comprises a vertical segment 2111 and a horizontal segment 2112 connected in sequence, the fuse wire 22 is arranged in the vertical segment 2111, and the horizontal segment 2112 has a connecting opening 212 at the end away from the vertical segment 2111. Moreover, the sealing member 23 is arranged at the end of the vertical segment 2111 close to the horizontal segment 2112, so that the melted fuse wire 22 can be sealed in the vertical segment 2111 by the sealing member 23, and the sealing member 23 can prevent the melted fuse wire 22 from entering the horizontal segment 2112 from the vertical segment 2111. Arranging the fuse wire 22 in the vertical segment 2111 can also prevent the fuse wire from flowing randomly after being melted, that is, the vertical segment 2111 can also limit the fuse wire 22, so as to ensure the use performance of the battery top cover.

[0042] Optionally, as shown in Figure 4 , the conductive part 13 extends into the vertical segment 2111 and is located at the end of the vertical segment 2111 away from the horizontal segment 2112, and the extension direction of the conductive part 13 is the same as the horizontal direction. In this way, the fuse wire 22 can be switched to the disconnected state with the conductive part 13 more easily after being melted. Of course, the shape of the conductive part 13 extending into the vertical segment 2111 can also be adjusted adaptively in the present application, at least to ensure that the conductive part 13 and the fuse wire 22 are in the disconnected state after the fuse wire 22 is melted, and the conductive part 13 and the fuse wire 22 can be switched to the conductive state after the fuse wire 22 is cooled.

[0043] Specifically, as shown in Figure 1 and Figure 2 , the battery top cover further comprises a lead wire 50, one end of the lead wire 50 is connected with the pressure-sensitive resistor 30, and the other end of the lead wire 50 extends into the connecting opening 212 and is connected with the fuse wire 22 through the sealing member 23. In this way, the stable electrical connection between the fuse wire 22 and the pressure-sensitive resistor 30 can be ensured. Moreover, the lead wire 50 needs to be insulated from the cover body 40 in the present application, and optionally, the part of the lead wire 50 in contact with the cover body 40 is provided with an insulating layer, or at least the part of the cover body 40 in contact with the lead wire 50 can also be made of insulating material. At the same time, the size of the fuse wire 22 can be determined by the formula P = I 2t decision, wherein, I is the current flowing through the varistor 30, t is the time that the current flowing through the varistor 30 is not destroyed. For the varistor 30, the current that the varistor 30 bears satisfies V1mA(min) >= (1.6-2)*Vdc, Vdc is the maximum working voltage of the direct current circuit.

[0044] Optionally, the fuse wire 22 is made of any one of magnesium, lead, tin and antimony. Of course, other metals or alloys can also be selected as the material for manufacturing the fuse wire 22 according to actual use conditions.

[0045] Optionally, the battery top cover further comprises an explosion-proof valve 60 arranged on the cover body 40, and the varistor 30 is arranged on the explosion-proof valve 60. The explosion-proof valve functions to release pressure when the internal pressure of the battery is too high, so as to prevent the battery from exploding. The working characteristics of the varistor under overpressure can assist the triggering of the explosion-proof valve, especially in the high-voltage charging scenario. When the internal voltage of the battery abnormally rises, the varistor can quickly respond by shunting or dissipating the voltage, thereby reducing the rising speed of the internal pressure of the battery, so as to give the explosion-proof valve more time to respond and adjust, thereby enhancing the overall explosion-proof function of the battery top cover. Meanwhile, arranging the varistor on the explosion-proof valve can also improve the overall compactness of the battery top cover.

[0046] The embodiment of the present application provides a battery comprising the battery top cover provided by any one of the above embodiments, and the content and effects thereof can be referred to the above embodiments, which will not be described herein.

[0047] The embodiment of the present application provides a battery pack comprising a plurality of batteries, at least part of the batteries comprising the battery top cover provided by any one of the above embodiments, and the content and effects thereof can be referred to the above embodiments, which will not be described herein.

[0048] From the above description, it can be seen that the above embodiments of the present application achieve the following technical effects:

[0049] 1. The problem that the battery pack is prone to overcharging due to the consistency of the batteries in the prior art is effectively solved.

[0050] 2. The structure is simple, and the performance is stable.

[0051] Obviously, the above-described embodiments are only a part of the embodiments of the present application, rather than all the embodiments. Based on the embodiments of the present application, all other embodiments obtained by those skilled in the art without creative labor should belong to the protection scope of the present application.

[0052] It is to be understood that the terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of example embodiments in accordance with the present application. As used herein, the singular forms "a", "an" and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises" and / or "comprising," when used in this specification, specify the presence of stated features, steps, operations, devices, components and / or combinations thereof, but do not preclude the presence or addition of one or more other features, steps, operations, devices, components and / or combinations thereof.

[0053] It should be noted that the terms "first", "second", and the like, herein do not necessarily have an either chronological or spatial relation to each other, but are used merely to distinguish a different single implementation from another unless specifically indicated otherwise. It should be understood that the use of the term "or" in the context of describing example embodiments is used to mean a selection of one or more of the alternatives. For example, the phrase "A / B or C" is satisfied by any one of the following alternatives: [A and B] or [C].

[0054] The preferred embodiments of the present application have been described above with the specific embodiments. The application is not limited to the above examples, and various changes and modifications can be made by those skilled in the art. Any modification, equivalent replacement, improvement, etc. made within the spirit and principle of the present application shall fall within the scope of the present application.

Claims

1. A battery top cover, characterized in that, Includes a cover (40) and components disposed on the cover (40): At least two poles (10); At least one fuse assembly (20), at least one of the terminals (10) are correspondingly provided with the fuse assembly (20), and the fuse assembly (20) and the corresponding terminal (10) have an open state and a closed state; A varistor (30) is connected between the two terminals (10) and in series with the fuse assembly (20).

2. The battery top cover according to claim 1, characterized in that, At least a portion of the fuse assembly (20) is disposed inside the corresponding pole (10).

3. The battery top cover according to claim 1, characterized in that, The fuse assembly (20) includes: An insulating part (21) is provided inside the corresponding pole post (10), and the insulating part (21) has a receiving cavity (211) and a connection opening (212) communicating with the receiving cavity (211); A fuse (22) is disposed in the receiving cavity (211) in a state that can be changed. The conductive part (13) of the pole (10) extends into the receiving cavity (211) and has the disconnected state and the conducting state with the fuse (22). The varistor (30) is electrically connected to the fuse (22).

4. The battery top cover according to claim 3, characterized in that, The fuse assembly (20) further includes a seal (23) disposed within the receiving cavity (211) and located at the end of the fuse wire (22) away from the conductive part (13).

5. The battery top cover according to claim 4, characterized in that, The battery top cover also includes a wire (50), one end of which is connected to the varistor (30), and the other end of which extends into the connection opening (212) and passes through the seal (23) to be connected to the fuse (22).

6. The battery top cover according to claim 3, characterized in that, The receiving cavity (211) includes a vertical section (2111) and a horizontal section (2112) connected in sequence. The fuse (22) is disposed in the vertical section (2111), and the horizontal section (2112) has the connection opening (212) at one end away from the vertical section (2111).

7. The battery top cover according to claim 6, characterized in that, The conductive part (13) extends into the vertical segment (2111) and is located at the end of the vertical segment (2111) away from the horizontal segment (2112), and the extension direction of the conductive part (13) is the same as the horizontal direction.

8. The battery top cover according to any one of claims 1 to 7, characterized in that, The battery top cover also includes an explosion-proof valve (60) disposed on the cover body (40), and the piezoresistive resistor (30) is disposed on the explosion-proof valve (60).

9. A battery, characterized in that, Includes the battery top cover as described in any one of claims 1-8.

10. A battery pack, characterized in that, It includes a plurality of batteries (70), at least one of the batteries (70) having a battery top cover as claimed in any one of claims 1 to 8.

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