WO2018157559A1

WO2018157559A1 - Battery module

Info

Publication number: WO2018157559A1
Application number: PCT/CN2017/097125
Authority: WO
Inventors: 游志毅; 秦峰; 朱涛声; 马林; 肖信福; 王娟
Original assignee: 宁德时代新能源科技股份有限公司
Priority date: 2017-02-28
Filing date: 2017-08-11
Publication date: 2018-09-07
Also published as: CN206490120U

Abstract

Disclosed is a battery module comprising a module housing (100) and battery cells (200) provided in the module housing (100), the battery cell (200) comprising a battery cell casing (220), a bare cell housed in the battery cell casing (220), and a top cover (230) connected onto the battery cell casing (220) and provided with a top cover piece (231). The module housing (100) comprises a lower housing (110) and an upper cover (120) connected in a sealed manner to the lower housing (110), the battery cell casing (220) and the top cover piece (231) are an electrolyte-resistant and insulating non-metal material, and the lower housing (110) and the upper cover (120) are a metal material. The battery module uses a housing of an electrolyte-resistant and insulating non-metal material to encapsulate the battery cells (200), saving on costs of structural members of the battery module, and significantly reducing the total weight of the battery module; using a sealed metal module housing (100) to again encapsulate the assembled battery cells (200) cuts off water vapour from entering the interior of the battery module, achieving water vapour isolation for the battery cell level, and while effectively reducing the encapsulation costs of the battery cells (200), the energy density of the battery module is increased.

Description

Battery module

Technical field

The invention belongs to the field of batteries, and more particularly to a battery module.

Background technique

For the soft-package cells used in the soft-pack module, a multi-layer composite film, such as an aluminum-plastic film, is usually used in order to achieve a water vapor barrier effect. If the plastic is directly packaged by the battery, the plastic itself has a large molecular gap, the water molecules are easy to pass through, and the water vapor barrier performance is poor, which cannot meet the requirements. The composite film currently used is generally provided with a metal layer in the middle, and the metal layer is laminated on the side of the cell with one or more plastic layers resistant to the electrolyte, and has the functions of insulation and heat sealing. The metal layer is typically laminated with one or more layers of wear resistant material to the outside of the cell to protect the metal layer from scratches. The atomic density of the metal layer is high, and water molecules cannot pass, so the effect of moisture barrier is achieved. However, when the above composite film material is used as a battery core seal, since the plastic layer is thin, there is a problem that the insulation withstand voltage cannot satisfy the requirements. In the secondary package of the outer ear and the secondary package after the exhaust, there is a problem that the sealing reliability is not high, causing the battery to leak.

For traditional modules using square-shell batteries, it is common practice to use an aluminum or steel shell as the package for the battery core. The battery core needs to be coated with an insulating plastic layer that is resistant to the electrolyte to meet the gap between the battery core and the metal casing. Insulation requirements. Due to the dense metal atoms, the use of aluminum or steel shells to encapsulate the cells can achieve the effect of moisture barrier. However, each cell requires a metal housing and corresponding insulation measures, resulting in increased cost and reduced energy density.

In view of this, it is indeed necessary to provide a battery module with a water vapor barrier function, high energy density, and low cost.

Summary of the invention

The object of the present invention is to overcome the deficiencies of the prior art and provide a battery module with a water vapor barrier function, high energy density and low cost.

In order to achieve the above object, the present invention provides a battery module including a module housing and a battery core disposed in the module housing, the battery core including a battery core housing, a bare battery core received in the battery core housing, and a top cover connected to the cell casing and provided with a top cover sheet, the module case comprising a lower case and an upper cover sealingly connected to the lower case, the cell case and the top cover piece being resistant to electrolysis The liquid and insulating non-metal material, the lower casing and the upper cover are made of metal.

The use of an electrolyte-resistant and insulating non-metallic battery core case and top cover sheet replaces the existing hard-shell metal case, which can insulate and isolate adjacent cells, reduce the weight of the battery module and reduce the cost, but non-metal The material has poor performance in blocking water vapor. The module shell of metal material must be used to improve the ability of the battery module to block water vapor. The lower casing and the upper cover are sealed and sealed, and the battery module is sealed, so that all the batteries have the ability to block water vapor. .

As an improvement of the battery module of the present invention, the lower casing and the upper cover are made of aluminum metal.

As an improvement of the battery module of the present invention, the cell casing is a plastic film. The cost of the plastic film is relatively low, and the cell casing is thinner, and the structure of the soft cell and the hard cell is combined to increase the energy density of the cell.

As an improvement of the battery module of the present invention, the cell casing and the cover sheet are sealed by welding. Seal the single cell structure to prevent electrolyte leakage and ensure the safety of the entire battery module.

As a modification of the battery module of the present invention, the top cover further comprises a pole, a sealing ring and a pole-studded aluminum block, wherein the top cover piece is provided with a pole hole and a liquid injection hole, and the sealing ring is sleeved on the pole The pole is inserted from the bottom to the pole hole, and the upper end of the pole is electrically connected with the pole-studded aluminum block, and the lower end of the pole is electrically connected to the bare core.

As an improvement of the battery module of the present invention, the pole is electrically connected to the bare cell through the adapter piece.

As an improvement of the battery module of the present invention, the pole-studded aluminum blocks of the adjacent cells are electrically connected through a connecting piece to realize series or parallel connection of the cells.

As an improvement of the battery module of the present invention, the upper cover comprises an upper cover sheet, a module output end disposed on the upper cover sheet, an explosion-proof valve, and an upper insulating sheet between the upper cover sheet and the output end of the module. And a lower insulating sheet between the upper cover sheet and the pole-studded aluminum block and the connecting piece.

The entire module casing seals the groups of cells to form a sealed space, so that the top cover of the single cell structure can be integrated with the safety device explosion-proof valve of the entire battery module without being provided with a safety device. The size of the explosion-proof valve can be selected according to the needs of the battery module, and since the upper cover sheet is made of a metal material, the upper insulating sheet and the lower insulating sheet are used to insulate the metal parts that the upper cover sheet contacts.

As a modification of the battery module of the present invention, the battery module further includes a voltage sampling terminal, and the upper cover sheet is provided with a through hole, and the voltage sampling terminal is sealed and installed in the through hole and partially extends out of the through hole.

As an improvement of the battery module of the present invention, the battery module further includes an end plate disposed on both sides of the lower casing along the stacking direction of the electric core.

Compared with the prior art, the battery module of the invention has the following beneficial technical effects:

The use of an electrolyte-resistant and insulated non-metallic outer casing to encapsulate the battery core greatly saves the cost of the structural components of the battery module, and the total weight of the battery module is significantly reduced. The sealed metal module housing is used to repackage the groups of cells. The water vapor is blocked from entering the interior of the battery module to achieve the water vapor barrier at the level of the battery core, and the energy density of the battery module is improved while effectively reducing the cost of the battery core package.

DRAWINGS

The battery module of the present invention will be described in detail below with reference to the accompanying drawings and specific embodiments, wherein:

FIG. 1 is a schematic view showing the assembly of a battery module of the present invention.

2 is a perspective exploded view of a battery module of the present invention.

3 is a perspective exploded view of a battery cell in the battery module of the present invention.

detailed description

The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. The specific embodiments described in the specification are to be construed as illustrative only and not limiting.

Referring to FIG. 1 to FIG. 3, the present invention provides a battery module, including a module housing 100 and a battery core 200 disposed in the module housing 100. The battery core 200 includes a battery core housing 220 and is received in the battery module. a bare cell in the cell housing 220, and a top cover 230 connected to the cell housing 220 and provided with a top cover sheet 231, wherein the module housing 100 includes a lower housing 110 and is sealed from the lower housing 110 The upper cover 120, the battery case 220 and the top cover 231 are made of a non-metallic material that is resistant to electrolyte and is insulated. The lower case 110 and the upper cover 120 are made of metal.

Referring to FIG. 1 and FIG. 2, the module housing 100 includes a lower housing 110 and an upper cover 120. The upper cover 120 and the lower housing 110 are sealed by welding to form a sealed space for blocking moisture from entering the interior of the battery module. .

The upper cover 120 includes an upper cover sheet 121, an output positive electrode 122 disposed on the upper cover sheet 121, and an output negative electrode 123. The upper cover piece 121 and the lower case 110 are both made of metal, and are usually made of aluminum metal. The metal material has high atomic density and can achieve the effect of moisture barrier. The output positive electrode 122 and the output negative electrode 123 are electrically connected to the battery cells 200 located at both ends of the battery module, respectively.

The entire battery module uses only one large metal module housing 100 to seal the entire battery module, which can block water vapor from entering the interior of the battery module, and greatly reduces the entire battery module in comparison with the existing hard-shell battery grouping. The weight of the group reduces the cost of the battery cell 200 and the battery module package while increasing the energy density of the battery module.

Referring to FIG. 3, the battery cell 200 includes a battery core housing 220, a bare battery core received in the battery core housing 220, and a top cover 230 connected to the battery core housing 220 and provided with a top cover sheet 231. . The cell housing 220 is made of a plastic material resistant to electrolyte corrosion, or a plastic film directly encapsulating the bare cell.

The top cover 230 includes a top cover piece 231, a pole 232, a sealing ring 233 and a pole-studded aluminum block 234. The top cover piece 231 is also made of a plastic material and is sealed with the battery case 220 to prevent sealing. Leakage.

The top cover piece 231 is provided with a pole hole and a liquid injection hole. The sealing ring 233 is sleeved on the pole 232. The pole 232 is inserted through the pole hole from the bottom to the bottom. The sealing ring 233 is opposite to the pole 232 and the pole. The joints of the holes are sealed to prevent leakage. The upper end of the pole piece 232 extending from the top cover piece 231 is electrically connected to the pole-studded aluminum block 234, and the lower end of the pole piece 232 is electrically connected to the bare cell through the adapter piece 235. The pole-studded aluminum blocks 234 of the adjacent cells 200 are connected by a connecting piece 236 to realize the series or parallel connection of the battery cells 200 to form a battery pack.

The plastic core case 220 and the top cover piece 231 have the function of insulating and isolating the adjacent cells 200, which not only reduces the occupied space of the single cell 200 but also greatly reduces the electric power compared to the hard case cell. The weight of the core 200 reduces the cost and increases the energy density of the battery module.

Referring to FIG. 1 and FIG. 2, according to a preferred embodiment of the present invention, an upper insulating sheet 125 is disposed between the upper cover sheet 121 and the output positive electrode 122 and the output negative electrode 123, and the upper cover sheet 121 and the pole post are riveted to the aluminum. A lower insulating sheet 126 is provided between the block 234 and the connecting piece 236. The upper cover sheet 121 is made of a metal material, and the lower insulating sheet 126 ensures that the upper cover sheet 121 is insulated from the pole-studded aluminum block 234 and the connecting piece 236. The upper insulating sheet 125 ensures that the upper cover sheet 121 is insulated from the output positive electrode 122 and the output negative electrode 123. The upper insulating sheet 125 and the lower insulating sheet 126 may be plastic sheets.

The module housing 100 forms a sealed space. The upper cover sheet 121 is provided with an explosion-proof valve 124 of the entire battery module. The size of the explosion-proof valve 124 can be selected according to the needs of the battery module to ensure the safety of the entire battery module.

A voltage sampling terminal 127 is further disposed in the battery module, and the upper cover sheet 121 is provided with a through hole. The voltage sampling terminal 127 is sealed and installed in the through hole and partially extends out of the through hole to ensure the sealing of the entire battery module.

Referring to FIG. 1 , according to a preferred embodiment of the present invention, the battery module is further provided with two anti-expansion end plates 130 on both sides of the lower casing 110 along the stacking direction of the battery core 200 to strengthen the lower casing. The structural strength on both sides of the 110 suppresses the expansion of the battery cells 200 in the battery module.

In combination with the above detailed description of the present invention, it can be seen that the battery module of the present invention has at least the following beneficial technical effects as compared with the prior art:

The battery core 200 is sealed by using the electrolyte-resistant and insulated non-metal battery case 220 and the top cover piece 231, which greatly saves the structural cost of the battery module, and the total weight of the battery module is significantly reduced; the sealed metal material is used. The module housing 100 repackages the battery cells 200 after the group, blocks the water vapor from entering the interior of the battery module, and achieves the water vapor barrier at the level of the battery core, thereby effectively reducing the cost of the battery pack 200 and improving the energy of the battery module. density.

According to the above principle, the present invention can also be appropriately modified and modified as described above. Therefore, the invention is not limited to the specific embodiments disclosed and described herein, and the modifications and variations of the invention are intended to fall within the scope of the appended claims. In addition, although specific terms are used in the specification, these terms are merely for convenience of description and do not limit the invention.

Claims

A battery module includes a module housing and a battery core disposed in the module housing, the battery core includes a battery core housing, a bare battery core received in the battery core housing, and is connected to the battery core housing a top cover provided with a top cover sheet, wherein the module housing comprises a lower housing and an upper cover sealingly connected to the lower housing, the battery core housing and the top cover sheet being electrolyte resistant and insulating Non-metallic material, the lower casing and the upper cover are made of metal.
The battery module according to claim 1, wherein the lower casing and the upper cover are made of aluminum metal.
The battery module according to claim 1, wherein the battery case is a plastic film.
The battery module according to claim 1, wherein said cell casing and said cover sheet are sealed by welding.
The battery module according to claim 1, wherein the top cover further comprises a pole, a sealing ring and a pole-studded aluminum block, wherein the top cover sheet is provided with a pole hole and a liquid injection hole, and the sealing sleeve The pole is arranged on the pole, and the pole is inserted from the bottom to the pole hole. The upper end of the pole is electrically connected with the pole-studded aluminum block, and the lower end of the pole is electrically connected with the bare core.
The battery module according to claim 5, wherein the pole is electrically connected to the bare cell through the adapter piece.
The battery module according to claim 5, wherein the pole-studded aluminum blocks of the adjacent cells are electrically connected by a connecting piece to realize series or parallel connection of the cells.
The battery module according to claim 7, wherein the upper cover comprises an upper cover piece, a module output end provided on the upper cover piece, and an explosion-proof valve, located between the upper cover piece and the output end of the module. An upper insulating sheet, and a lower insulating sheet between the upper cover sheet and the pole-studded aluminum block and the connecting piece.
The battery module according to claim 8, wherein the battery module further comprises a voltage sampling terminal, the upper cover sheet is provided with a through hole, and the voltage sampling terminal is sealed and installed in the through hole. The extension extends out of the through hole.
The battery module according to claim 1, wherein the battery module further comprises an end plate disposed on both sides of the lower casing along the stacking direction of the electric core.