Positive electrode connecting piece of lithium ion battery

Abstract

The utility model relates to the technical field of battery structure safety protection, and particularly discloses a lithium ion battery positive electrode connecting piece, the middle part of the connecting piece is provided with a double-through groove, the connecting piece is provided with fusing points at the two ends of the double-through groove, and the fusing points are used for fusing and cutting off a current path on the connecting piece during overload. And protection structures are connected to two sides of the connecting sheet at the two sides of the double-through groove, and the protection structures are used for preventing the two sides of the fused connecting sheet from being reconnected. According to the connecting piece, a reasonable protection structure is arranged, so that short circuit caused by reconnection of the fused pole piece and secondary damage of a battery structure caused by possible fusing are prevented, and the use safety of the connecting piece is improved.

Description

Technical Field

[0001] The utility model relates to the technical field of battery structure safety protection, in particular to a positive connection piece of a lithium-ion battery. Background Art

[0002] The current development of lithium-ion batteries still faces certain problems and challenges, especially the safety issue. The external short circuit of a lithium-ion battery is a relatively common type of fault. At the moment of an external short circuit, the super-large current between the positive and negative electrodes will cause local overheating, resulting in leakage, explosion, and spontaneous combustion of a single battery cell, and triggering a chain reaction, leading to more battery damage. To prevent external short circuit problems, the existing solutions mainly involve adding a FUSE (fuse) structure at the positive connection piece when designing a lithium-ion battery, so that the current is automatically cut off when the connection piece is locally overheated. Therefore, the FUSE structure design of the positive connection piece of a lithium-ion battery has great research value.

[0003] When the positive connection piece of a lithium-ion battery melts, the structural strength of the cover plate decreases. Due to mechanical movement, the molten aluminum has the risk of reconnecting together, which may cause a short circuit and even lead to thermal runaway. Therefore, it is necessary to design a protection structure for the positive connection piece to enhance the structural stability of the cover plate. Summary of the Utility Model

[0004] The purpose of the utility model is to provide a positive connection piece of a lithium-ion battery, which can prevent the reconnection of the pole piece after melting to cause a short circuit and the possible secondary damage of the battery structure by the molten products generated by melting through setting a reasonable protection structure, so as to improve its use safety.

[0005] The purpose of the utility model can be realized by the following technical solutions:

[0006] A positive connection piece of a lithium-ion battery, a double-pass groove is arranged in the middle of the connection piece, and fusing points are formed at both ends of the connection piece located at the double-pass groove. The fusing points are used to fuse and cut off the current path on the connection piece when overloaded. Protection structures are connected to both sides of the connection piece located at the double-pass groove, and the protection structures are used to prevent the two sides of the connection piece after melting from reconnecting.

[0007] In a further scheme, the protection structure includes a connection bridge, and both ends of the connection bridge are respectively connected to both sides of the double-pass groove.

[0008] In a further scheme, a material receiving structure is arranged to extend outward on one side of the connection bridge. The material receiving structure is arranged below the fusing point and is used to receive the molten material that drops during melting.

[0009] In a further embodiment, a convex head is provided at one end of the connecting piece, and a groove is provided at the other end. The material receiving structure is arranged below the fusing point on the side close to the groove.

[0010] In a further embodiment, the material receiving structure is a receiving platform flush with the upper surface of the connecting bridge.

[0011] In a further embodiment, the connecting bridge is a concave frame structure.

[0012] In a further embodiment, the length and width of the double through groove are determined according to the fusing size of the fusing point.

[0013] In a further embodiment, the structure of the connecting piece after fusing is two side fragments formed by fusing at both ends of the double through groove and an intermediate fragment located between the two side fragments.

[0014] In a further embodiment, the protection structure is made of a high-temperature resistant insulating ceramic material.

[0015] In a further embodiment, the high-temperature resistant insulating ceramic material includes silicon carbide ceramic material or alumina ceramic material.

[0016] Advantages of the present utility model:

[0017] By providing a double through groove on the connecting piece in the present utility model to form a double through groove fuse structure, compared with the conventional single-channel FUSE structure, under the condition that the overcurrent area of the connecting piece is the same and the FUSE size is the same, the fusing time of the double through groove FUSE design of the present utility model is shorter, which can reduce the probability of thermal runaway. At the same time, a protection structure is provided to support the fragments after the connecting piece fuses, prevent them from falling, ensure the structural stability at the cover plate, prevent the risk of reconnection caused by mechanical movement, and also improve the installation strength of the connecting piece.

[0018] By providing a material receiving structure, the molten beads generated by fusing at the fusing point can be received, preventing the molten beads from falling into the core and causing an internal short circuit. Description of the Drawings

[0019] In order to more clearly illustrate the technical solutions in the embodiments of the present utility model or the prior art, the following will briefly introduce the drawings required for use in the description of the embodiments or the prior art. Obviously, the drawings in the following description are some embodiments of the present utility model. For those of ordinary skill in the art, without creative efforts, other drawings can also be obtained based on these drawings.

[0020] Figure 1 It is a connection diagram of a positive electrode connecting piece of a lithium-ion battery in an embodiment of the present utility model;

[0021] Figure 2It is a schematic diagram of the fuse point in the embodiment of the present utility model;

[0022] Figure 3 It is a schematic diagram of the protection structure in the embodiment of the present utility model;

[0023] In the figure: 1, double-pass groove; 2, protection structure; 3, material receiving structure; 4, convex head; 5, groove. Specific embodiments

[0024] Next, the technical solutions in the embodiments of the present utility model will be clearly and completely described in conjunction with the accompanying drawings in the embodiments of the present utility model. Obviously, the described embodiments are only a part of the embodiments of the present utility model, rather than all the embodiments. Based on the embodiments of the present utility model, all other embodiments obtained by those of ordinary skill in the art without making creative efforts belong to the scope of protection of the present utility model.

[0025] As Figure 1 shown, a positive electrode connecting piece of a lithium-ion battery is provided. A double-pass groove 1 is provided in the middle of the connecting piece. Fuse points are formed at both ends of the connecting piece located in the double-pass groove 1. The fuse points are used to fuse and cut off the current path on the connecting piece during overload. Protection structures 2 are connected to both sides of the connecting piece located on both sides of the double-pass groove 1. The protection structures 2 are used to prevent the two sides of the fused connecting piece from reconnecting.

[0026] Its working principle is as follows: When the battery cell carries a large current, heat accumulates at the FUSE structure. As Figure 2 shown, the positions at a and b reach the melting point first. Subsequently, within a very short time, the temperatures at c and d also rise to the melting point, thereby cutting off the large current and avoiding thermal runaway. Compared with the conventional single-channel FUSE structure, under the condition of the same overcurrent area of the connecting piece and the same FUSE size, the fuse time of the double-pass groove 1 FUSE design of the present utility model is shorter, and the probability of thermal runaway can be reduced.

[0027] After fusing occurs, the insulating protection structure 2 plays a supporting role for the fused connecting piece to ensure the structural stability at the cover plate; the protection structure 2 can separate the broken pieces after the connecting piece is fused to ensure that they will not reconnect due to mechanical vibration and prevent secondary short circuit. This design can improve the structural strength and safety performance at the battery cell.

[0028] According to the above working principle, some preferred structures or implementation manners are provided. The protection structure 2 includes a connecting bridge, and both ends of the connecting bridge are respectively connected to both sides of the double-pass groove 1. The bridge-shaped structure is simple and convenient for connecting the two broken pieces on both sides after fusing to prevent the broken pieces from reconnecting due to mechanical vibration. In order to prevent the connecting bridge from failing under mechanical vibration, its structural stability can be enhanced, such as increasing the contact area with the connecting piece, or multiple such connecting bridges can be arranged side by side on the connecting piece.

[0029] like Figure 3 As shown, a material connection structure 3 is provided on one side of the connecting bridge, which is provided below the melting point and is used to catch the hot melt material that falls when melting. Below the overcurrent weak points a and b is the molten bead connection area e of the protective structure 2, which can accommodate the molten beads generated by the melting of the FUSE structure to prevent the molten beads from falling into the winding core and causing an internal short circuit. Through the synergistic effect of the connecting bridge and the molten bead connection area e, the risk of internal short circuit caused by the melting of the overcurrent weak points a and b is further reduced. At the same time, the structure is simple, the manufacturing difficulty and cost are low, and the reliability and safety of the product are improved.

[0030] A protrusion 4 is provided at one end of the connecting piece, and a groove 5 is provided at the other end, which is used for the installation and identification of the connecting piece, so as to facilitate the distinction between the positive connecting piece and the negative connecting piece during assembly. In the process of assembling the battery assembly, the correct identification and assembly of the positive and negative connecting pieces are crucial. Existing connection methods usually rely on the operator's visual recognition or simple mechanical alignment, which increases the risk of assembly errors to a certain extent. This ensures that the positive connecting piece is assembled in the correct manner and order. At the same time, because the groove 5 and the protrusion 4 can be integrally processed during the processing of the electrode sheet, this is less costly than making an additional identification mark, aiming to further improve the ease of use, stability and functionality of the connecting piece.

[0031] The material connection structure 3 is arranged below the fuse point on one side close to the groove 5. This can protect the key area of the battery cell from dropping a very small amount of molten beads through the groove 5. The material of the material connection structure 3 is selected from high temperature resistant materials.

[0032] The material receiving structure 3 is a receiving platform flush with the upper surface of the connecting bridge. The receiving platform forms a stop surface to catch the molten beads and prevent them from falling further. The platform has sufficient area and flatness to ensure that the molten beads can fall on it smoothly. The edge of the receiving platform can also be provided with a fence to form a stop surface to catch the molten beads and prevent them from sliding off the edge.

[0033] The connecting bridge is a concave frame structure, which is simple, easy to manufacture, and can meet the use requirements.

[0034] The length and width of the double through slot 1 are determined according to the fusing point fusing size. This value only needs to be able to fuse when the fusing current is reached, such as the length and width are set to 20mmx2mm.

[0035] The structure after the connecting piece melts is composed of two side fragments formed by melting at both ends of the double-pass slot 1 and an intermediate fragment located between the two side fragments. Since the above four points break, it will be formed, and the protection structure 2 can support the two side fragments, so that the broken fragments will not adhere to the intermediate fragment due to mechanical movement after breaking. By introducing a special protection structure, the problem of the broken fragments adhering again after the connecting piece melts is effectively solved, and the safety performance of the electronic device is significantly improved. At the same time, this design is simple and easy to implement, with little change to the existing production process, and has high practicability and economy.

[0036] The protection structure 2 is made of high-temperature resistant insulating ceramic material, which can enable the protection structure 2 to be connected to the connecting piece through processes such as injection molding and encapsulation, facilitating processing. The high-temperature resistant insulating ceramic material includes silicon carbide ceramic material or alumina ceramic material. This material is easy to purchase and has good connection effect after encapsulation. The protection structure 2 made of high-temperature resistant insulating ceramic material can maintain stable performance in a high-temperature environment and effectively prevent circuit short-circuit; at the same time, it is connected to the connecting piece through the injection molding and encapsulation process, simplifying the processing flow, improving production efficiency, having good connection effect, and enhancing the reliability of the product.

[0037] It should be noted that the terms "first", "second", etc. in this application are used to distinguish similar objects and do not necessarily need to describe a specific order or sequence. It should be understood that such used data can be interchanged under appropriate circumstances so as to implement the embodiments of the present application described here.

[0038] In the description of this specification, the descriptions referring to terms "one embodiment", "example", "specific example", etc. mean that the specific features, structures, materials or characteristics described in connection with the embodiment or example are included in at least one embodiment or example of the present utility model. In this specification, the schematic representations of the above terms do not necessarily refer to the same embodiment or example. Moreover, the specific features, structures, materials or characteristics described can be combined in a suitable manner in any one or more embodiments or examples.

[0039] The above shows and describes the basic principles, main features and advantages of the present utility model. Those skilled in the art of this industry should understand that the present utility model is not limited by the above embodiments. What is described in the above embodiments and the specification only illustrates the principle of the present utility model. Without departing from the spirit and scope of the present utility model, the present utility model will have various changes and improvements, and these changes and improvements all fall within the scope of the present utility model claimed.

Claims

1. A positive electrode connecting piece for a lithium-ion battery, characterized in that, A double-pass groove (1) is provided in the middle of the connecting piece. Fusing points are formed at both ends of the connecting piece at the double-pass groove (1). The fusing points are used to fuse and cut off the current path on the connecting piece during overload. Protective structures (2) are fixedly connected to both sides of the connecting piece at the double-pass groove (1). The protective structures (2) are used to prevent the two sides of the connecting piece after fusing from reconnecting.

2. The positive electrode connecting piece of a lithium-ion battery according to claim 1, characterized in that, The protective structure (2) includes a connecting bridge. Both ends of the connecting bridge are respectively connected to both sides of the double-pass groove (1).

3. The positive electrode connecting piece of a lithium-ion battery according to claim 2, characterized in that, A material receiving structure (3) extends outward from one side of the connecting bridge. The material receiving structure (3) is arranged below the fusing point and is used to catch the molten material that drops during fusing.

4. The positive electrode connecting piece of a lithium-ion battery according to claim 3, characterized in that, A convex head (4) is provided at one end of the connecting piece, and a groove (5) is provided at the other end. The material receiving structure (3) is arranged below the fusing point on the side close to the groove (5).

5. The positive electrode connecting piece of a lithium-ion battery according to claim 3, characterized in that The material receiving structure (3) is a receiving platform flush with the upper surface of the connecting bridge.

6. The positive electrode connecting piece of a lithium-ion battery according to claim 3, characterized in that The connecting bridge is a concave frame structure.

7. A positive electrode connecting piece of a lithium-ion battery according to claim 1, characterized in that The length and width of the double-pass groove (1) are determined according to the fusing size of the fusing point.

8. A positive electrode connecting piece of a lithium-ion battery according to claim 1, characterized in that, The structure of the connecting piece after fusing is two side fragments formed by fusing at both ends of the double-pass groove (1) and an intermediate fragment located between the two side fragments.

9. The positive electrode connecting piece of a lithium-ion battery according to claim 1, characterized in that, The protective structure (2) is made of a high-temperature resistant insulating ceramic material.

10. A positive electrode connecting piece for a lithium-ion battery according to claim 9, characterized in that, The high-temperature resistant insulating ceramic material includes silicon carbide ceramic material or alumina ceramic material.

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