CN113451695B - Battery module and electric vehicle - Google Patents

Abstract

The present invention relates to a battery module, including: a plurality of cells; and a cell restraining structure including an internal frame and an external casing assembled with the internal frame to form a plurality of chambers that receive the plurality of cells in a one-to-one correspondence to encapsulate and manage the plurality of cells, wherein the internal frame includes an elastic element that forms at least one first surface of each chamber, the elastic element being elastically deformed by being pressed by a corresponding cell received in each chamber by a predetermined amount such that the elastically deformed elastic element applies a first acting force to the corresponding cell, and wherein, in response to the corresponding cell reversibly expanding or contracting in operation, the elastically deformed elastic element is further pressed or tends to recover such that the first acting force determines a restraining force to which the corresponding cell is subjected.

Description

Battery module and electric vehicle

Technical Field

The invention relates to the technical field of power batteries, in particular to a battery module and an electric vehicle.

Background

More and more vehicles (for example, vehicles, ships, airplanes, etc.) have power batteries represented by lithium ion batteries, especially secondary power batteries, as their important energy storage devices, and the power batteries can provide all or the main power sources for the vehicles through continuous discharge when needed, and the energy density of the power batteries is continuously increasing in order to meet the electric quantity requirements of various vehicles, and for this reason, the manufacturing technology of the power batteries is continuously improving to provide power batteries which are safer, more economical and more flexible for application in various vehicles.

At present, power batteries, in particular for use in electric vehicles, can be produced on the basis of two general solutions. The first technical scheme is to design the power battery by depending on three levels of battery core, module and battery pack, but the first technical scheme involves more parts, low integration efficiency and high manufacturing cost. A second solution is to design the power battery depending on two levels of cell-battery pack, for example, the cell is directly fixed in the tray of the battery pack by an adhesive to remove the module level. However, the second solution has a complex manufacturing process, low safety, and high maintenance cost.

Disclosure of Invention

An object of the present invention is to provide an improved battery module and an electric vehicle powered by the same, in which the battery module is used as a modular power battery, a fully functional energy storage device is designed with highly integrated and simplified components, and thus, the integration efficiency is high, the safety is high, the maintenance cost is low, and the manufacturing platform can be realized. Depending on the power requirements of various types of electric vehicles, one or more battery modules may be mounted directly to the electric vehicle at appropriate locations to power the electric vehicle.

According to an aspect of the present invention, there is provided a battery module including: a plurality of cells; and a cell restraining structure including an internal frame and an external casing assembled with the internal frame to form a plurality of chambers that receive the plurality of cells in a one-to-one correspondence to encapsulate and manage the plurality of cells, wherein the internal frame includes an elastic element that forms at least one first surface of each chamber, the elastic element being elastically deformed by being pressed by a corresponding cell received in each chamber by a predetermined amount such that the elastically deformed elastic element applies a first acting force to the corresponding cell, and wherein, in response to the corresponding cell reversibly expanding or contracting in operation, the elastically deformed elastic element is further pressed or tends to recover such that the first acting force determines a restraining force to which the corresponding cell is subjected.

Optionally, the elastically deformable resilient element is further compressed to the limit of elastic deformation in response to the corresponding cell beginning to irreversibly expand in operation.

Optionally, the elastic element is a laminate comprising two elastic layers and a thermal barrier layer between the two elastic layers.

Optionally, the internal frame comprises an insulating element forming at least one second surface of each chamber, the insulating element providing support to the plurality of cells and having a low thermal conductivity.

Optionally, a plurality of resilient elements and a plurality of insulating elements are provided, which are arranged alternately perpendicular to each other to form the at least one first surface and the at least one second surface of each chamber, the area of the first surface being larger than the area of the second surface.

Optionally, the external casing comprises a cooling element for supporting and cooling the plurality of cells, the cooling element comprising a cooling plate forming a third surface of each chamber, the cooling plate being adhered to the plurality of cells via a thermally conductive glue.

Optionally, an outer housing encases the inner frame and is connected to the cooling plate to seal the plurality of chambers.

Optionally, the cooling element comprises reinforcing ribs arranged on both sides of the cooling plate and extending perpendicular to the cooling plate, the reinforcing ribs being connected to the outer casing and applying a second force to the plurality of cells via the outer casing, the second force being greater than the first force.

Optionally, the plurality of chambers is divided into a first set of chambers and a second set of chambers, the cooling plate includes first and second oppositely positioned cooling faces, the first cooling face forming the third surface of each chamber in the first set of chambers and the second cooling face forming the third surface of each chamber in the second set of chambers.

Optionally, the cell restraint structure includes an insulating element interposed between the outer casing and the plurality of cells, the insulating element adhered to the outer casing and the plurality of cells by a thermally conductive adhesive, and the insulating element having a high thermal conductivity.

Optionally, the cell-restraining structure comprises a smoke guide element interposed between the outer casing and the plurality of cells, the smoke guide element being configured to define a smoke channel for the plurality of cells.

Optionally, the smoke guiding element comprises a main panel made of an insulating material having a high thermal conductivity, the surface of the main panel facing the outer housing being adhered to the outer housing by a thermally conductive glue.

Optionally, the heat conducting element further comprises a flange disposed on a surface of the main panel facing the plurality of cells, the flange forming a smoke channel by abutting against the plurality of cells.

Optionally, the flange comprises a first flange portion extending perpendicular to the main panel on both sides of the main panel, a second flange portion arranged inwardly spaced apart in parallel from the first flange portion, a third flange portion arranged perpendicularly between the first and second flange portions, and the second flange portion is provided with at least one opening.

Alternatively, the first flange portion is made of a material having a thermal conductivity, and the second and third flange portions are made of a material having a low thermal conductivity.

Optionally, a heat insulation patch is disposed on a surface of the plurality of cells facing the smoke guide element.

Optionally, the external housing comprises a pressure relief valve at one end side of the battery module, the pressure relief valve being positioned horizontally oriented such that flue gas flowing through the flue gas channel to the pressure relief valve is laterally vented to the external environment.

Optionally, the pressure relief valve is covered by a filter element, such that the flue gas flowing through the flue gas channel to the pressure relief valve is first filtered by the filter element.

According to another aspect of the present invention, there is provided an electric vehicle including: a battery module bay; and one or more battery modules as described above mounted in the battery module bay by one or more physical or electrical connection fittings.

Therefore, each component of the cell constraint structure in the battery module is used for packaging and managing the plurality of cells individually or in groups, so that each component is optimally utilized, and the integration efficiency of the battery module is improved. In particular, the forces exerted on the cell during operation can be better controlled by the elastic element. In particular, heat conduction between the cells can be supported and isolated by the insulating element. In particular, by symmetrically arranging the plurality of battery cells divided into two groups with respect to the cooling element, the utilization efficiency of the cooling element can be improved. In particular, the cell can be electrically insulated from the outer housing by the insulating element and damage to the cell during the assembly process is prevented. In particular, the thermal runaway protection of the cell can be optimized by means of the smoke guide element.

Other features of the present invention and advantages thereof will become apparent from the following detailed description of exemplary embodiments of the invention, which proceeds with reference to the accompanying drawings.

Drawings

The accompanying drawings, which are incorporated in and constitute a part of this specification, illustrate embodiments of the invention and together with the description, serve to explain the principles of the invention.

Fig. 1 is an assembly view of a battery module according to one embodiment of the present invention.

Fig. 2 is an exploded view of the battery module of fig. 1.

Fig. 3 is a further exploded view of a portion of the battery module of fig. 1.

Fig. 4 is a perspective view of an outer case of a battery module according to one embodiment of the present invention.

Fig. 5 is a perspective view of a cooling plate of a battery module according to one embodiment of the present invention.

Fig. 6 is a sectional view of the battery module of fig. 1.

Fig. 7 is a perspective view of a smoke guide element of a battery module according to an embodiment of the present invention.

Fig. 8 is a plan view of the battery module of fig. 1.

Fig. 9 is a partial sectional view of the battery module in the dotted line block of fig. 8.

Detailed Description

Various exemplary embodiments of the present invention will now be described in detail with reference to the accompanying drawings. It should be noted that: the relative arrangement of parts and steps, numerical expressions and numerical values set forth in these embodiments do not limit the scope of the present invention unless specifically stated otherwise.

Techniques and apparatus known to those of ordinary skill in the relevant art may not be discussed in detail, but are intended to be part of the specification where appropriate.

In all examples shown and discussed herein, any particular value should be construed as merely illustrative, and not limiting. Thus, other examples of the exemplary embodiments may have different values.

It should be noted that: like reference numerals and letters denote like items in the following drawings, and therefore, once a certain item is defined in one drawing, it is not necessary to further discuss it in the following drawings, and hereinafter, the relative orientation of the battery module, which is proposed in the present invention, will be described in the orthogonal coordinate system constituted by the X-axis, the Y-axis, and the Z-axis, based on the viewing direction in the drawings, but it is not intended to limit the configuration of the battery module.

It should also be noted that: the battery module proposed in the present invention can be directly mounted in a vehicle (e.g., an electric vehicle) as an electric device through one or more physical or electrical connection fittings, and thus, such a battery module can be already independently operated without being further packaged to be applied.

Referring to fig. 1, the assembled battery module 10 of fig. 1 may be applied to an electric vehicle, which includes a pure electric vehicle or a hybrid electric vehicle. For example, the electric vehicle is provided with a battery module compartment (not shown) on the chassis, in which the battery module 10 may be mounted through one or more physical or electrical connection fittings to be fixed relative to the battery module compartment and electrically connected to the electric motor of the electric vehicle. Based on the electric quantity demand of a specific electric vehicle, the volume of a specific battery module compartment corresponds to a multiple of the volume of the battery module 10, so that the battery module 10 can be mass-produced to be suitable for different electric vehicles.

Referring to fig. 2, the disassembled battery module 10 shows a plurality of battery cells 100 located inside the battery module, for example, the battery cells 100 are ternary lithium battery cells. The battery cell 100 may include, but is not limited to, a hard shell, a soft bag, and a cylinder according to the material and shape of the battery cell package. By way of example only, the shape of the battery cell 100 described hereinafter is a six-sided cube comprising an upper surface 112 and a lower surface 114 oppositely positioned along the Z-axis, a front surface 118 and a rear surface 116 oppositely positioned along the Y-axis, and two side surfaces oppositely positioned along the X-axis, wherein the upper surface 112 and the lower surface 114 of the battery cell 100 have a significantly larger area, referred to hereinafter as a large face.

The battery module 10 includes a cell restraining structure configured to enclose and manage the plurality of battery cells 100. The cell constraint structure encapsulates the plurality of battery cells 100 to support, isolate and seal the plurality of battery cells 100 in physical space, and the cell constraint structure manages the plurality of battery cells 100 by mainly managing the plurality of battery cells 100 in three aspects of electrical connection, thermal conduction and thermal runaway prevention. Unless otherwise stated, the shape and size of each component in the cell restraining structure correspond to the shape and size of the plurality of battery cells 100 and/or the battery core pack 110 composed of the plurality of battery cells 100, so as to realize a stable structure of the battery module 10.

Optionally, the cell restraint structure includes an inner frame and an outer casing assembled with the inner frame to form a plurality of cavities in a row and column form, which receive and secure the plurality of battery cells 100 in a one-to-one correspondence.

Referring to fig. 3, the internal frame comprises a resilient element 120 and a thermal insulating element 140, wherein the resilient element 120 forms at least one first surface of each chamber, which first surface abuts the upper surface 112 and/or the lower surface 114 of the corresponding battery cell 100; the insulating element 140 forms at least one second surface of each chamber, which abuts one or both of the two side surfaces of the corresponding battery cell 100. Thus, the area of the first surface of each chamber is larger than the area of the second surface.

As shown, a plurality of insulating elements 140 and a plurality of elastic elements 120 are provided, and the plurality of insulating elements 140 and the plurality of elastic elements 120 may be a thin plate material and alternately arranged perpendicular to each other to form a plurality of open spaces corresponding to the plurality of battery cells 100, thereby placing the plurality of battery cells 100 in a one-to-one correspondence. For example, the number of insulating elements 140 is N +1 and the number of elastic elements 120 is N to form 2N open spaces, where N ≧ 1 and is an integer.

In the process of assembling the battery cells 100, the plurality of battery cells 100 are first divided into a plurality of columns of battery cells, for example, referring to fig. 2 or fig. 3, each column of battery cells includes an upper battery cell and a lower battery cell stacked up and down in the Z-axis direction, and the elastic element 120 is sandwiched between the upper battery cell and the lower battery cell, and the elastic element 120 may provide a first acting force a (refer to fig. 6) to the battery cells 100 in operation, which will be described in detail below. Alternatively, the elastic member 120 is made of an elastic material such as rubber, foam, or structural glue.

Next, the multiple columns of battery cells are arranged in a line along the X axis direction, and the heat insulation element 140 is sandwiched between two columns of battery cells arranged adjacently, so that the heat insulation element 140 can reduce or even prevent heat conduction between the multiple columns of battery cells. Optionally, the insulating element 140 is made of a low thermal conductivity material, including but not limited to epoxy and aerogel.

Depending on the particular application, different numbers, sizes, and/or shapes of insulating and resilient elements may be provided to form multiple chambers in different rows and columns. Alternatively, each column of the battery cells may include one or more than two battery cells 100. For example, each column of cells includes three cells 100, in which case the number of the thermal insulation elements 140 is N +1 and the number of the elastic elements 120 is 2N, to form 3N open spaces. Every row of electric core includes upper portion electric core, middle part electric core and the lower part electric core that stacks from top to bottom in proper order along Z axis direction, and two elastic element 120 are pressed from both sides respectively and are established between upper portion electric core and middle part electric core and between middle part electric core and the lower part electric core.

Alternatively, to mitigate thermal conduction between individual cells in each column of cells, the elastic element 120 may be implemented as a laminate comprising two elastic layers and a thermal insulating layer between the two elastic layers, whereby the laminate is both elastic and thermally insulating.

Referring again to fig. 2, the plurality of battery cells 100 in the plurality of open spaces collectively constitute a battery core pack 110, and the battery core pack 110 includes an upper surface 112 and a lower surface 114 oppositely positioned in the Z-axis direction, a rear surface 116 and a front surface 118 oppositely positioned in the Y-axis direction, and two side surfaces 119 oppositely positioned in the Z-axis direction. Accordingly, the upper surface 112 of the electric core group 110 is formed by the upper surfaces of the upper electric cells of the multiple rows of electric cells, the lower surface 114 of the electric core group 110 is formed by the lower surfaces of the lower electric cells of the multiple rows of electric cells, the rear surface 116 of the electric core group 110 is formed by the rear surfaces of the plurality of electric cells 100, the front surface 118 of the electric core group 110 is formed by the front surfaces of the plurality of electric cells 100, and the side surfaces 119 of the electric core group 110 are formed by the side surfaces of the two rows of electric cells located at both end sides of the electric core group 110.

Optionally, the internal frame further comprises an insulating member 160 covering the upper surface 112 and the lower surface 114 of the battery cell pack 110, such that the insulating member 160 is located between the external casing and the plurality of battery cells 100. The insulating members 160 are adhered to the upper and lower surfaces 112 and 114 of the electric core pack 110, respectively, via an adhesive. The insulating element 160 may be a wear resistant sheet material with a thickness between 0.2-0.5mm, hardly affecting the volume of the plurality of chambers. The insulating member 160 is configured to electrically insulate the upper surface 112, i.e., the large surface, of the electric core pack 110 from the outer housing, while also preventing the electric core pack 110 from being damaged, because the insulating member 160 prevents the outer housing from rubbing against the large surface of the electric core pack 110 during the process of assembling the outer housing. Alternatively, the insulating member 160 is made of an insulating material with a high thermal conductivity, including but not limited to a composite of silicone rubber and glass fiber, etc., so that the insulating member 160 has both electrical insulation and good thermal conductivity so as not to hinder the large-area heat dissipation of the electric core pack 110.

It is understood that the cell restraining structure further includes an electrical system for electrical connection and electrical detection of the battery module 10. For example, the electrical system includes a high voltage connection device, a low voltage sampling device, and an electrical termination device 550.

Still referring to fig. 3, the front surface 118 of each battery cell 100 has two tabs (or poles), namely, a positive tab (or positive pole) and a negative tab (or negative pole). The positive electrode tab and the negative electrode tab are partially covered by a tab top cover, which may be provided with a heat insulating sheet, such as a mica sheet, to prevent the temperature of the external environment from affecting the operation performance of the battery cell.

The high voltage connection means comprises a plurality of high voltage connection pads 520, for example, the high voltage connection pads 520 are aluminum rows, copper rows, or other forms of current carriers. The high-voltage connection sheet 520 electrically connects the positive electrode tab of one battery cell 100 and the negative electrode tab of the other battery cell 100 of the two battery cells 100 arranged adjacently in the X-axis direction, and electrically connects the positive electrode tab of the one battery cell 100 and the negative electrode tab of the other battery cell 100 of the pair of battery cells 100 located on the one end side of the battery core group 110.

Alternatively, the low voltage sampling device includes an FFC (flexible flat cable), an FPC (flexible circuit board), a wire harness, or other forms of electrical signal carriers, and the low voltage sampling device includes a metal sampling sheet 530 electrically connected to each of the high voltage connection sheets 520 for detecting the voltage and temperature of each of the battery cells 100 and transmitting electrical signals related to the voltage and temperature of each of the battery cells 100 to a BMS battery management system (not shown). The BMS battery management system may be separated from the battery module 10 or integrated in the battery module 10.

Optionally, electrical termination 550 is provided on one insulating element 140 located on one end side of the pack 110 (e.g., by adhesive). The electrical termination device 550 is integrally injection-molded, suction-molded, clamped, and hot-riveted to two high-voltage connection pieces 520a, the two high-voltage connection pieces 520a are electrically connected to the positive tab of one of the battery cells 100 and the negative tab of the other battery cell 100 in the pair of battery cells 100 located at the other end side of the battery cell group 110, respectively, so as to finally collect the voltage and current provided by the battery cells 100 through the plurality of high-voltage connection pieces 520. The electrical termination device 550 is also snapped, screwed, and hot riveted to the low voltage sampling device to deliver electrical signals related to the voltage and temperature of the individual cells 100.

The electrical system is closely fitted to the front surface 118 and the side surfaces of the cell pack 110 in a suitable manner, and further description of the electrical system is reasonably omitted in order to more clearly illustrate other components of the cell restraining structure.

An outer case, optionally made of a metal material, is then assembled and covers the inner frame (i.e., the large face, the front face 118, and both side faces 119 of the electric core pack 110) to provide the battery module 10 with packaging rigidity. Optionally, the outer housing comprises: a forming body 200 (refer to fig. 4) having a cross-section similar to a U-shape, the forming body 200 matching the large face and the front surface 118 of the electric core pack 110; a first end plate 220 and a second end plate 240 located on both sides of the shaped body 200, wherein the first end plate 220 is provided with a high voltage interface 222 and a low voltage interface 224 (refer to fig. 1) providing an electrical output to the electrical termination device 550, and the second end plate 240 is provided with a filter element 600 for filtering combustibles in the flue gas and a pressure relief element 620 (refer to fig. 2) surrounded or covered by the filter element.

Referring to fig. 3 and 5, optionally, the external casing further includes a cooling element 300 for supporting and cooling the plurality of battery cells 100. For example, the cooling element 300 made of a metallic material includes a cooling plate 320 forming a third surface of each cavity, which abuts against the rear surface 116 of the corresponding battery cell 100, and thus the rear surface 116 of the battery core pack 110 is adhered to the cooling plate 320 by the insulating, thermally conductive glue. The cooling plate 320 may be provided at the inside thereof with various shapes of flow channels, and the length of the cooling plate 320 in the X-axis direction is slightly longer than the length of the electric core pack 110 to provide an inlet 301 and an outlet 302 at an end of the cooling plate protruding beyond the length of the electric core pack 110, and the cooling liquid from the cooling liquid source may enter the cooling plate 320 through the inlet 301, flow through the various shapes of flow channels, and then exit from the outlet 302. To optimize the wiring of the battery module 10, the inlet 301 and the outlet 302 of the cooling fluid are located on the same side as the first end plate 220.

Optionally, the cooling element 300 further comprises reinforcing ribs 310 disposed on both sides of the cooling plate 320 and extending perpendicular to the cooling plate 320, the reinforcing ribs 310 being connected to an external casing, for example, to the two free ends 220 (refer to fig. 4) of the U-shaped molding body 200 by welding, gluing or other suitable means, so as to completely encapsulate the plurality of battery cells 100.

Alternatively, in order to improve the utilization efficiency of the cooling element 300, the cooling plate 320 is provided with the first cooling surface 312 and the second cooling surface 314 which are oppositely positioned, and the reinforcing ribs 310 are symmetrically disposed with respect to the cooling plate 320 such that the cross-sectional shape of the cooling element 300 is in an "i" shape. Accordingly, the electric core group 110 includes the first and second electric core groups 110a and 110b divided into the same configuration, and accordingly, the plurality of chambers are divided into a first group of chambers for receiving the first electric core group 110a and a second group of chambers for receiving the second electric core group 110b, the first cooling surface 312 forms a third surface of each chamber of the first group of chambers, and the second cooling surface 314 forms a third surface of each chamber of the second group of chambers. Thereby, the cooling member 300 commonly supports and cools the first electric core pack 110a and the second electric core pack 110b.

Generally, the battery cell 100 may reversibly expand upon charging or contract upon discharging in operation, i.e., the battery cell 100 increases in volume upon charging and the battery cell 100 decreases in volume upon discharging. However, as the battery cell 100 ages, the battery cell 100 may begin to irreversibly expand, i.e., the battery cell 100 may irreversibly increase in volume, and the irreversibly expanded battery cell 100 may again undergo charge expansion or discharge contraction during operation. Whether a change in the volume of the battery cell 100 caused by reversible expansion or contraction, or an increase in the volume of the battery cell 100 caused by irreversible expansion, may result in a change in the applied force to the corresponding battery cell 100. Under the condition that the corresponding battery cell 100 is stressed excessively or the whole battery cell group 110 is stressed unevenly, the service performance and the service life of the battery cell 100 are affected, and a safety accident can be caused in a serious case.

Referring to fig. 6, in the present invention, the corresponding battery cell 100 located in each chamber is constrained by the elastic element 120, the heat insulating element 140, the cooling element 300, and the molded body 200 of the outer casing. When each cavity receives and fixes the corresponding battery cell 100 during the assembly of the battery cells 100, the elastic element 120 is elastically deformed by being pressed by the corresponding battery cell 100 by a preset amount, so that the elastically deformed elastic element 120 applies the first acting force a to the corresponding battery cell 100. In response to the corresponding battery cell 100 reversibly expanding or contracting in operation, the elastically deformed elastic element 120 is further squeezed or tends to recover, such that the first acting force a determines the restraining force to which the corresponding battery cell 100 is subjected. Due to the elastic properties of the elastic element 120, the volume change of the corresponding battery cell 100 has less influence on the value of the first acting force a. The first force a provided by the resilient element 120 is substantially constant and more advantageous for the operation of the battery cell 100 than the prior art in which the restraining force is provided directly to the battery cell 100 through the package housing.

As the battery cell 100 ages, the elastically deformed resilient element 120 is further squeezed to the limit of elastic deformation in response to the corresponding battery cell 100 beginning to irreversibly expand in operation. At this time, the corresponding battery cell 100 and the elastic element 120 reaching the elastic deformation limit press the molding body 200 of the external casing together, so that the external casing is slightly deformed, and the external casing starts to determine the restraining force applied to the battery cell 100, so that the restraining force applied to the aged battery cell 100 is within a reasonable range, and the rapid deterioration of the service performance and the service life of the battery cell 100 is avoided.

Finally, at the end of the life of the battery cell 100, the battery cell 100 is excessively swollen, which tends to cause a large deformation of the external casing, in which case the reinforcing rib 310 applies the second acting force B to the plurality of battery cells 100 via the connection surface formed by connection with the external casing (i.e., the free end 220 of the U-shaped molded body 200) to avoid the failure of the encapsulation structure of the battery module 10. The second force B is greater than the first force a.

The preset amount of elastic deformation (i.e., pre-load) of the elastic element 120 during assembly of the battery cell 100 may be designed based on the elastic modulus of the elastic element 120 and the desired first force a. Additionally, the thickness of the elastic element 120 may be designed based on the thickness of the corresponding battery cell 100 and a first expansion rate and/or contraction rate at which the corresponding battery cell 100 reversibly expands or contracts in operation. For example, the first expansion and/or contraction rate is any value from 0 to 2%. Alternatively, the thickness of the elastic element 120 may be designed based on the thickness of the corresponding battery cell 100 and the second expansion rate at which the corresponding battery cell 100 starts to irreversibly expand in operation. For example, the second expansion ratio is any value of 0 to 8%.

Furthermore, if one or more cells 100 in the battery module 10 thermally runaway in operation, the one or more cells 100 will rapidly heat up and emit a smoke. On one hand, the heat of the flue gas is conducted to other battery cells 100 by spreading of the flue gas, which affects the performance and safety of the whole battery module 10; on the other hand, the smoke contains a large amount of combustibles, and if the combustibles in the smoke are discharged from the pressure relief device of the battery module 10 to the external environment without being processed, the combustibles may be burned by air in the external environment, thereby bringing safety risk again.

Thus, referring to fig. 3 and 7, the cell restraint structure further includes a smoke guide element 580, the smoke guide element 580 being positioned between the outer casing and the plurality of battery cells 100 and adhered thereto by an adhesive. The smoke guide 580 is configured to define a common smoke channel 590 for the entire electric core pack 110.

Optionally, the smoke guide 580 comprises a main panel 582, the area of the main panel 582 is equal to the area of the front surface 118 of the electric core pack 110, and the main panel 582 is made of an insulating material with high thermal conductivity so as not to hinder the heat dissipation from the front surface 118 of the electric core pack 110. The smoke guide element 580 of fig. 7 is rotated 90 ° with respect to the smoke guide element 580 of fig. 3 to show the engagement surface of the main panel 582 facing the chamber or the battery cell 100, and the engagement surface is provided with a flange extending perpendicular to the main panel 582, e.g., the flange is substantially straight.

Alternatively, the flanges include first flange portions 592 provided on both sides of the engagement surface, second flange portions 594 provided at an interval in parallel inward from the first flange portions 592, and third flange portions 596 provided between the two second flange portions 594 and perpendicularly connected to the two second flange portions 594, the number of the third flange portions 596 being plural, the plural third flange portions 596 being provided parallel to each other at an interval corresponding to the width of each column of cells along the X axis. By abutting the flanges against the front face 118 of the battery cell pack 110, the first flange portion 592, the second flange portion 594 and the front face 118 of the battery cell pack 110 jointly form the smoke channel 590, and the second flange portion 594, the adjacent two third flange portions 596 and the front face 118 of each column of battery cells jointly form the chamber gap 560. It follows that the number of chamber voids 560 corresponds to the number of columns of cells. The area of the chamber gap 560 is slightly less than the area of the front surface 118 of each column of cells due to the presence of the flue gas channel 590. At the same time, the second flange portion 594 is provided with at least one opening 598 leading from each chamber interspace 560 to the flue gas channel 590, so that the flue gas flows mainly through the flue gas channel 590 towards the filter element.

Alternatively, the first flanged portion 592 is made of an insulating material having a high thermal conductivity coefficient to facilitate heat dissipation from the front surface 118 of the battery core pack 110, and the second flanged portion 594 and the third flanged portion 596 are made of an insulating material having a low thermal conductivity coefficient to thermally mitigate the influence of one battery cell 100 on the other battery cells 100 in the event of thermal runaway of the one battery cell 100.

Referring to fig. 8 and 9, in the case that one of the battery cells 100 in the battery cell group 110 emits smoke to the chamber gap 560 due to thermal runaway, the smoke in the chamber gap 560 flows to the smoke channel 590 through the corresponding opening 598, and the smoke flowing to the smoke channel 590 is guided to the filter element 600 on the second end plate 240, so that the smoke containing combustible substances is filtered out of the combustible substances and then discharged from the pressure relief element 620 to the external environment. Optionally, the pressure relief element 620 comprises a pressure relief valve positioned in a horizontal orientation to allow the lateral venting of the flue gas to the outside environment.

Alternatively, a thermal insulation patch may be disposed on a surface of the plurality of battery cells 100 facing the smoke guide element 580 (i.e., the front surface 118 of the battery core pack 110), and only the positive electrode tab and the negative electrode tab of each battery cell 100 are exposed, so as to further prevent the backflow of smoke generated after the thermal runaway of the corresponding battery cell 100 from affecting the adjacent battery cells 100.

It is to be understood that other configurations of the flue gas channel 590 are also contemplated, as long as such a flue gas channel 590 is capable of allowing the corresponding battery cell 100 to direct flue gas in a relatively simple and rapid manner.

Although some specific embodiments of the present invention have been described in detail by way of illustration, it should be understood by those skilled in the art that the above illustration is only for the purpose of illustration and is not intended to limit the scope of the invention. It will be appreciated by those skilled in the art that modifications may be made to the above embodiments without departing from the scope and spirit of the invention. The scope of the invention is defined by the appended claims.

Claims (16)

1. A battery module, comprising:

a plurality of cells; and a cell restraint structure including an internal frame and an external casing assembled with the internal frame to form a plurality of chambers that receive the plurality of cells in a one-to-one correspondence to encapsulate and manage the plurality of cells,

wherein the internal frame comprises an elastic element forming at least one first surface of each chamber, the elastic element being elastically deformed by being pressed by a corresponding cell received in each chamber by a preset amount, such that the elastically deformed elastic element applies a first force to the corresponding cell,

wherein the elastically deformed elastic element is further compressed or tends to recover, in response to the corresponding cell reversibly expanding or contracting in operation, such that the first force determines the restraining force to which the corresponding cell is subjected,

and wherein the cell-restraining structure further comprises a smoke guide element interposed between the external casing and the front surfaces of the plurality of cells having the positive and negative electrode tabs, the smoke guide element comprising a main panel and flanges provided on surfaces of the main panel facing the plurality of cells, the flanges abutting against the front surfaces of the plurality of cells and comprising two first flange portions extending perpendicularly to the main panel on both sides of the main panel, two second flange portions provided at intervals parallel inwardly with respect to the two first flange portions, and a plurality of third flange portions provided perpendicularly between the two second flange portions, the plurality of third flange portions being provided parallel to each other at intervals corresponding to the width of each cell, at least one of the two second flange portions being provided with an opening between adjacent two third flange portions.

2. The battery module of claim 1, wherein the elastically deformed resilient element is further compressed to the limit of elastic deformation in response to the corresponding cell beginning to irreversibly expand in operation.

3. The battery module according to claim 1 or 2, wherein the elastic member is a laminate comprising two elastic layers and a heat insulating layer interposed between the two elastic layers.

4. The battery module of claim 1 or 2, wherein the internal frame comprises an insulating element forming at least one second surface of each chamber, the insulating element providing support to the plurality of cells and having a low thermal conductivity.

5. The battery module according to claim 4, wherein a plurality of elastic members and a plurality of heat insulating members are provided, the plurality of elastic members and the plurality of heat insulating members being alternately arranged perpendicular to each other to form the at least one first surface and the at least one second surface of each chamber, the first surface having an area greater than the second surface.

6. The battery module of claim 1 or 2, wherein the battery module comprises a cooling element for supporting and cooling the plurality of cells, the cooling element comprising a cooling plate forming a third surface of each cavity, the cooling plate being adhered to the plurality of cells via a thermally conductive glue.

7. The battery module according to claim 6, wherein an outer case covers the inner frame and is connected to the cooling plate to seal the plurality of chambers.

8. The battery module of claim 7, wherein the cooling element comprises reinforcing ribs disposed on both sides of the cooling plate and extending perpendicular to the cooling plate, the reinforcing ribs being connected to the outer casing and applying a second force to the plurality of cells via the outer casing, the second force being greater than the first force.

9. The battery module of claim 6, wherein the plurality of cavities are divided into a first set of cavities and a second set of cavities, the cooling plate comprises first and second oppositely positioned cooling surfaces, the first cooling surface forming a third surface of each cavity in the first set of cavities and the second cooling surface forming a third surface of each cavity in the second set of cavities.

10. The battery module of claim 1 or 2, wherein the cell restraint structure comprises an insulating element interposed between the outer casing and the plurality of cells, the insulating element adhered to the outer casing and the plurality of cells by a thermally conductive adhesive, and the insulating element having a high thermal conductivity.

11. The battery module according to claim 10, wherein the main panel is made of an insulating material having a high thermal conductivity, and a surface of the main panel facing the external case is adhered to the external case by a thermally conductive adhesive.

12. The battery module according to claim 1, wherein the first flange part is made of a material having a high thermal conductivity, and the second and third flange parts are made of a material having a low thermal conductivity.

13. The battery module of claim 1, wherein a thermal insulating patch is disposed on a surface of the plurality of cells facing the smoke guide element.

14. The battery module of claim 1, wherein the outer housing comprises a pressure relief valve at one end side of the battery module, the pressure relief valve positioned in a horizontal orientation such that flue gas flowing through the flue gas channel to the pressure relief valve is laterally vented to the outside environment.

15. The battery module according to claim 14, wherein the pressure release valve is covered with a filter member so that the smoke flowing to the pressure release valve through the smoke passage is first filtered by the filter member.

16. An electric vehicle comprising:

a battery module bay; and

one or more battery modules according to any one of claims 1 to 15 mounted in a battery module bay by one or more physical or electrical connection fittings.

Images