WO2018192071A1

WO2018192071A1 - Lithium battery module connection structure having self-protection function, and connection method

Info

Publication number: WO2018192071A1
Application number: PCT/CN2017/087977
Authority: WO
Inventors: 陈亚杰; 魏成刚; 范吉峰; 王东; 张佳瑢
Original assignee: 安普能源科技有限公司; 合肥国轩高科动力能源有限公司
Priority date: 2017-04-17
Filing date: 2017-06-12
Publication date: 2018-10-25

Abstract

A lithium battery module connection structure having a self-protection function, and a connection method. The lithium battery module connection structure comprises a plurality of battery modules (1); the plurality of battery modules (1) is connected in series by means of conductive structures (2), each conductive structure (2) comprising a first conductive copper bar (21) and a second conductive copper bar (22); one end of the first conductive copper bar (21) is connected with one end of the second conductive copper bar (22) by means of a fusible metal block (23), and the other ends of the first conductive copper bar (21) and the second conductive copper bar (22) are separately connected with conductive blocks (11) on adjacent battery modules (1). By utilizing the fusible metal with a relatively low melting point, the fusible metal and the two copper bars are connected in series based on physical characteristics of the fusible metal and then are used for connecting the battery modules (1) in series to achieve a current diversion effect; the fusible metal can be quickly fused under a high-temperature uncontrollable risk environment, connection among the modules is broken to achieve a self-protection effect; the problem of high-temperature out-of-control during over-charge, misuse and cycle usage process of various lithium ion battery modules such as a ternary material and a lithium iron phosphate material is solved.

Description

Lithium battery module connection structure with self-protection function and connection method

Technical field

The invention relates to the technical field of lithium battery manufacturing, and in particular relates to a lithium battery module connection structure and a connection method with self-protection function.

Background technique

Lithium-ion batteries have many advantages such as high energy density, high output power, long charge and discharge life, no pollution, wide operating temperature range and small self-discharge. As a new high-energy chemical power source, lithium-ion batteries have been widely used in electric vehicles and energy storage fields in recent years. At present, because the battery life of electric vehicles is generally not too high, a large number of lithium-ion batteries need to increase the battery life of the battery modules in series or in parallel.

In the field of energy storage, a battery module obtained by using a large number of lithium-ion batteries in series and parallel is used as an energy storage power station to collect the electric energy generated during the low-peak period of storage electricity, and to supplement the electric energy during the peak period of power consumption, in terms of energy conservation and environmental protection. Great help.

In order to improve the energy density of lithium-ion batteries to achieve high endurance, high storage capacity often requires multiple battery modules in series and parallel to achieve, but at this time in the process of charging and discharging, the safety performance of the battery module is difficult to guarantee. At present, the series and parallel connection between lithium battery modules on the market are directly connected by conductive metal, and the cover plates of each single cell are connected to each other through copper bars to form a module. Copper bar is a copper connecting piece. The melting point of copper is 1083.4 ° C. When the battery module is uncontrollable, the temperature rises to 80 ° C, which has affected the battery performance. At this time, there is no module between the module and the module. A self-protection module function or method, such that an abnormality occurs in a single battery or module in a battery module composed of a plurality of battery modules, which will cause a series of chain reactions to the entire module, thereby causing runaway and expanding problems. The seriousness.

Summary of the invention

The object of the present invention is to provide a lithium battery module connection structure and a connection method with self-protection function, which can greatly protect the battery module.

In order to achieve the above object, the present invention adopts the following technical solutions: a lithium battery module connection structure with self-protection function, including a plurality of battery modules, and a plurality of battery modules passing through a conductive structure In series, the conductive structure includes a first conductive copper bar and a second conductive copper bar, and one end of the first conductive copper bar is connected to one end of the second conductive copper bar through a fusible metal block, the first conductive copper The other ends of the bar and the second conductive copper bar are respectively connected to the conductive blocks on the adjacent battery modules.

In the above solution, the first conductive copper bar and the second conductive copper bar are at the same horizontal plane and the first conductive copper bar is opposite to the end of the second conductive copper bar.

In the above solution, the connection between the first conductive copper bar and the second conductive copper bar is provided with an insulating storage box, and the inner space of the insulating storage box can accommodate at least the fusible metal block.

In the above solution, the insulating storage box is a sealed hollow casing, and opposite ends of the casing are provided with openings for mounting the first conductive copper bar and the second conductive copper bar, and the insulating storage box The first conductive copper bar and the second conductive copper bar are fixedly connected.

In the above solution, the connection ends of the first conductive copper bar, the second conductive copper bar and the battery module are respectively provided with a bolt mounting hole; the melting point of the fusible metal block is 70-138 ° C.

Further, the fusible metal is one of a tin-bismuth alloy, a gallium-based alloy, a Wood alloy, and an indium-bismuth alloy.

Preferably, the fusible metal block is in the shape of a cube having a size of (8 to 20) x (8 to 20) x (15 to 25) mm.

In the above solution, the fusible metal block is fixed to an end between the first conductive copper bar and the second conductive copper bar.

In the above solution, the fusible metal block is fixed to the side of the first conductive copper bar and the second conductive copper bar.

In the above solution, the fusible metal block is fixed to the end portion and the circumferential side of the first conductive copper bar and the second conductive copper bar.

A method for connecting a lithium battery module with self-protection function includes the following steps:

(1) Selecting the copper bar used for connecting the lithium ion battery modules in series, and equally dividing the selected copper bars into a first conductive copper bar and a second conductive copper bar, placing the first conductive copper bar and the second conductive copper bar In the same horizontal plane, and the ends thereof are arranged oppositely, and the opposite ends of the two copper bars are connected together by a fusible metal block in a molten state to form a conductive structure;

(2) According to the size of the fusible metal block and the first conductive copper bar and the second conductive copper bar, the insulation is selected. a storage box, the insulating storage box is sleeved on the fusible metal block, and the insulating storage box is fixed with the first conductive copper bar and the second conductive copper bar to store the melted fusible metal block;

(3) A plurality of battery modules are arranged in sequence, and two ends of the conductive structure are respectively connected with the conductive blocks on the adjacent battery modules, and a plurality of battery modules are connected in series.

Wherein, in the step (1), the fusible metal block is partially melted and welded to the opposite ends of the two copper bars, and the thickness of the molten portion is 0.1 to 0.2 mm.

According to the above technical solution, the present invention utilizes a fusible metal having a relatively low melting point, and utilizes physical properties such as low melting point, good electrical conductivity, and no pollution after melting. The method of casting connection is used to connect the fusible metal with two copper bars, and then used for serial connection between battery modules, which acts as a diversion function, in the event of module frequency change abuse, or some high temperature uncontrollable danger In the environment, the fusible metal can be quickly melted, and the connection between the modules is self-protective. The physical characteristics of the fusible metal are used to function as a module self-protection, and the effect is obviously prioritized and the electronic control system safety device does not have other factors leading to protection failure. The self-protection device of the module can effectively solve the problem of high temperature out of control in the process of overcharging, abusing and recycling of many lithium ion battery modules such as ternary materials, lithium iron phosphate materials and the like on the market.

DRAWINGS

Figure 1 is a schematic view of a conductive structure junction of the present invention;

Figure 2 is a partial perspective view of the electrically conductive structure of the present invention;

3 is a schematic view showing the first connection manner of the conductive copper bar and the fusible metal block of the present invention;

4 is a schematic view showing a second connection manner of the conductive copper bar and the fusible metal block of the present invention;

5 is a schematic view showing a third connection manner of the conductive copper bar and the fusible metal block of the present invention;

6 is a schematic view showing a series connection of a battery module and a conductive structure of the present invention.

In the figure, 1 is a battery module, 11 is a conductive block, 2 is a conductive structure, 21 is a first conductive copper bar, 22 is a second conductive copper bar, 23 is a fusible metal block, 24 is an insulating storage box, 25 is Bolt mounting holes.

detailed description

The invention is illustrated below by the preferred embodiment. It should be understood by those skilled in the art that the present invention is not intended to limit the scope of the invention.

In the examples, the means used are all conventional means in the art unless otherwise specified.

Example 1

As shown in FIG. 1-3, the lithium battery module connection structure with self-protection function of the embodiment includes a plurality of battery modules 1, and the plurality of battery modules 1 are connected in series through the conductive structure 2, and the conductive structure 2 The first conductive copper bar 21 and the second conductive copper bar 22 are at the same horizontal plane and the first conductive copper bar 21 is opposite to the end of the second conductive copper bar 22 Settings (copper bar is a long piece of copper). One end of the first conductive copper bar 21 is connected to one end of the second conductive copper bar 22 through the fusible metal block 23, and the other ends of the first conductive copper bar 21 and the second conductive copper bar 22 are respectively connected to the adjacent battery module 1 The conductive blocks 11 are connected, the copper bars and the conductive blocks are laser welded, and the conductive blocks are made of copper. The melting point of the fusible metal block is 70 to 138 °C. In this embodiment, a fusible metal block is made of a tin-bismuth alloy, and the shape is a cubic type, and the size is 10×10×20 mm.

3 is a schematic view showing the structure of the fusible metal block 23 of the present invention fixed at the end between the first conductive copper bar 21 and the second conductive copper bar 22.

As shown in FIG. 1 and FIG. 2, a high temperature resistant insulating storage box 24 is provided at the junction of the first conductive copper bar 21 and the second conductive copper bar 22. The inner space of the insulating storage case 24 can accommodate at least a fusible metal block. 23, in order to drop the molten fusible metal block 23 into the designed insulating storage box 24 by gravity, to prevent the melted fusible metal from falling into the battery and causing a short circuit to the battery.

The shape of the insulating storage box 24 can be set according to the actual situation. In this embodiment, the insulating storage box 24 is a sealed hollow housing, and opposite ends of the housing are provided for mounting the first conductive copper bar 21 And the opening of the second conductive copper bar 22 to sleeve the casing on the fusible metal block 23, and the insulating storage box 24 is fixedly connected to the first conductive copper bar 21 and the second conductive copper bar 22.

When the battery modules are connected in series, the ends of the first conductive copper bar 21 and the second conductive copper bar 22 may be directly welded to the conductive blocks on the battery module 1, or may be connected by bolts. The conductive structure of the invention is suitable for a plurality of connection modes. In the embodiment, a bolt mounting hole 25 is respectively disposed at a connecting end of the first conductive copper bar 21, the second conductive copper bar 22 and the battery module 1. When the battery module 1 connected in series encounters a high temperature uncontrollable dangerous environment, the fusible metal block 23 is blown to function as a module self-protection function, and the melted fusible metal block 23 falls into the designed storage box by gravity. 24 inside.

A connection method of a lithium battery module having a self-protection function according to the embodiment includes the following steps:

S1: selecting a copper bar used for connecting the lithium ion battery modules 1 in series, and equally dividing the selected copper bars into a first conductive copper bar 21 and a second conductive copper bar 22, and the first conductive copper bar 21 and the second conductive The copper bars 22 are placed on the same horizontal plane, and the ends thereof are arranged oppositely. The opposite ends of the two copper bars are welded together by the fusible metal block 23 in a molten state to form the conductive structure 2; the thickness of the molten portion is about 0.2 mm. The strength of the welded surface after welding is comparable to the mechanical strength of the copper bar.

S2: According to the size of the fusible metal block 23, the first conductive copper bar 21, and the second conductive copper bar 22, the insulating storage box 24 is selected, the insulating storage box 24 is placed on the fusible metal block 23, and the insulating storage box is 24 locked on the copper bar on both sides of the fusible metal;

S3: As shown in FIG. 6, the single cells of the plurality of modules are connected in parallel to form a similar macrocell, and then the module and the module are connected by a conductive copper bar containing a fusible metal. That is, a plurality of battery modules 1 are sequentially arranged, and two ends of the conductive structure 2 are respectively connected with the conductive blocks on the adjacent battery modules 1 to connect the plurality of battery modules 1 in series, in the abuse module and some In the uncontrolled and dangerous environment of high temperature, the self-protection function of the module is achieved by the fusible metal melting, and the molten fusible metal falls into the designed high-temperature insulated storage box 24 by gravity.

Taking a module composed of 20 ternary material batteries in series as an example, each of the two modules is directly connected to a fusible metal block (the easy-to-receive metal block and the module are alternately arranged), and the overall internal resistance is within 0.5 mΩ.

The invention utilizes a fusible metal having a relatively low melting point, and utilizes physical properties such as low melting point, good electrical conductivity, and no pollution after melting. The method of casting connection is used to connect the fusible metal with two copper strings, and then used for serial connection between battery modules, which acts as a diversion function, frequently abused in the module, or some uncontrollable dangerous environment at high temperature. Underneath, the fusible metal can be quickly melted, disconnecting the modules, and self-protecting the battery module.

Example 2

In this embodiment, the fusible metal block 23 is fixed to the side of the first conductive copper bar 21 and the second conductive copper bar 22, and its structure is shown in FIG.

Example 3

In this embodiment, the fusible metal block 23 is fixed to the first conductive copper bar 21 and the second conductive copper bar 22 Between the end and the side, Figure 5 is a schematic view of the structure, the fusible metal block is welded on both the end and the side, and the overcurrent capability is better.

The above embodiments are merely illustrative of the preferred embodiments of the present invention, and are not intended to limit the scope of the present invention. Variations and modifications are intended to fall within the scope of the invention as defined by the appended claims.

Industrial applicability

The invention provides a lithium battery module connection structure and a connection method with self-protection function, comprising a plurality of battery modules, wherein a plurality of battery modules are connected in series through a conductive structure, the conductive structure comprising a first conductive copper bar And a second conductive copper bar, one end of the first conductive copper bar is connected to one end of the second conductive copper bar through the fusible metal block, and the other ends of the first conductive copper bar and the second conductive copper bar are respectively phased The conductive blocks on the adjacent battery modules are connected. The invention utilizes a fusible metal with a relatively low melting point, and uses the physical properties to connect the fusible metal with two copper bars, and then is used for series connection between battery modules, which acts as a diversion function and is uncontrollable at high temperature. In a dangerous environment, the fusible metal can be quickly melted, and the connection between the modules can be self-protected, which solves the problem of overcharging and abuse of many lithium-ion battery modules such as ternary materials, lithium iron phosphate materials and the like on the market. High temperature out of control during recycling. With excellent industrial application prospects.

Claims

A lithium battery module connection structure with self-protection function includes a plurality of battery modules, wherein a plurality of battery modules are connected in series through a conductive structure, wherein the conductive structure comprises a first conductive copper bar and a first a conductive copper bar, one end of the first conductive copper bar is connected to one end of the second conductive copper bar through a fusible metal block, and the other end of the first conductive copper bar and the second conductive copper bar are respectively adjacent to the battery The conductive blocks on the module are connected.
The lithium battery module connection structure with self-protection function according to claim 1, wherein the first conductive copper bar and the second conductive copper bar are at the same horizontal plane and the first conductive copper bar and the second conductive copper The ends of the bar are oppositely arranged.
The lithium battery module connection structure with self-protection function according to claim 2, wherein an insulating storage box is disposed at a junction of the first conductive copper bar and the second conductive copper bar, and the insulating storage box The internal space is at least capable of accommodating the fusible metal block.
The lithium battery module connection structure with self-protection function according to claim 3, wherein the insulating storage case is a sealed hollow casing, and opposite ends of the casing are provided for mounting An opening of the conductive copper bar and the second conductive copper bar, the insulating storage box is fixedly connected to the first conductive copper bar and the second conductive copper bar.
The lithium battery module connection structure with self-protection function according to claim 1, wherein a connection between the first conductive copper bar, the second conductive copper bar and the battery module is respectively provided with a bolt a pore; the fusible metal block has a melting point of 70 to 138 °C.
The lithium battery module connection structure with self-protection function according to claim 5, wherein the fusible metal is one of a tin-bismuth alloy, a gallium-based alloy, a Wood alloy, and an indium-bismuth alloy.
The lithium battery module connection structure with self-protection function according to any one of claims 1 to 6, wherein preferably, the fusible metal block has a shape of a cube and has a size of (8 to 20) × (8). ~20) × (15 to 25) mm.
The lithium battery module connection structure with self-protection function according to claim 2, wherein the fusible metal block is fixed to an end between the first conductive copper bar and the second conductive copper bar;

Or the fusible metal block is fixed to the side of the first conductive copper bar and the second conductive copper bar;

Alternatively, the fusible metal block is fixed to the ends and the circumferential sides of the first conductive copper bar and the second conductive copper bar.
A method for connecting a lithium battery module with self-protection function, comprising the steps of:

(1) Selecting the copper bar used for connecting the lithium ion battery modules in series, and equally dividing the selected copper bars into a first conductive copper bar and a second conductive copper bar, placing the first conductive copper bar and the second conductive copper bar In the same horizontal plane, and the ends thereof are arranged oppositely, and the opposite ends of the two copper bars are connected together by a fusible metal block in a molten state to form a conductive structure;

(2) According to the size of the fusible metal block, the first conductive copper bar and the second conductive copper bar, an insulating storage box is selected, the insulating storage box is placed on the fusible metal block, and the insulating storage box and the first conductive copper are The bar and the second conductive copper bar are fixed to store the melted fusible metal block;

(3) A plurality of battery modules are arranged in sequence, and two ends of the conductive structure are respectively connected with the conductive blocks on the adjacent battery modules, and a plurality of battery modules are connected in series.
The joining method according to claim 9, wherein in the step (1), the fusible metal block is partially melted and welded to the opposite ends of the two copper bars, and the thickness of the molten portion is 0.1 to 0.2 mm.