Fireproof battery module and battery assembly

Abstract

A fireproof battery module and a battery assembly. The fireproof battery module comprises a plurality of cells (10) arranged at intervals, a fireproof partition structure (20), fire extinguishing microcapsules (30), and two fireproof plates (40) arranged side by side. The fireproof partition structure (20) is distributed in gaps of the plurality of cells (10), so as to block heat transfer between adjacent cells (10). The fire extinguishing microcapsules (30) are arranged at positive electrodes of the cells (10), so as to extinguish the fire on the positive electrodes of the cells (10). The plurality of cells (10), the fireproof partition structure (20) and the fire extinguishing microcapsules (30) are all located between the two fireproof plates (40). Once thermal runaway occurs in the cells (10), the positive electrodes of the cells (10) may release gas, and the gas is a combustible gas which may generate a flame. By means of the design of the three parts, a fire extinguishing and fireproof structure of the module is formed, thereby improving the fireproof performance of the battery module, and meeting higher safety requirements.

Description

Fireproof battery modules and battery modules

[0001] This application claims priority to the Chinese patent application filed with the China Patent Office on July 14, 2023, with application number 202321869587.0 and title “Fireproof Battery Module and Battery Module”, the entire contents of which are incorporated by reference into this application. Technical Field

[0002] The present disclosure relates to the field of new energy battery technology, and in particular to a fireproof battery module and a battery module. Background Art

[0003] In the rapidly evolving data age, driven by the rapid development of the internet and big data, the UPS (uninterruptible power supply) as its foundation is also undergoing continuous development and updates. This is especially true with the rapid development and application of lithium batteries and the rapid expansion of the new energy industry. Applications previously utilizing lead-acid batteries are increasingly being replaced by lithium batteries. The safe application of lithium batteries is becoming increasingly important, becoming a top priority for end users and the market.

[0004] Lithium batteries, especially ternary lithium batteries, are chosen for their high energy density, high activity, long backup time, and high discharge rate. Consequently, safety requirements are becoming increasingly stringent. To meet safety design requirements and market application requirements, higher demands are being placed on practitioners in the lithium battery R&D industry, particularly the need to meet fire testing and certification requirements demanded by the international market.

[0005] The mainstream technical routes of lithium batteries are divided into lithium iron phosphate and ternary lithium. Compared with lithium iron phosphate, ternary lithium batteries have higher energy density per unit volume and unit mass, greater discharge rate, higher activity of the battery positive electrode, and higher integration of structure and system. Therefore, in the field of UPS lithium battery backup power, ternary lithium can better meet the requirements of short-term high-rate backup power, but the danger of ternary lithium batteries is higher than that of lithium iron phosphate.

[0006] The fire protection design of ternary lithium batteries has always been a difficult problem. There are successful cases at the cabinet-level vertical architecture level at home and abroad, but there are few successful cases for the modular module-level parallel architecture design scheme. Therefore, the existing ternary lithium battery modules have poor fire protection performance and are difficult to meet the increasingly high safety requirements.

[0007] Summary of the Invention

[0008] The present disclosure provides a fireproof battery module and a battery module to solve the problem of poor fireproof performance of battery modules in the prior art and meet higher safety requirements.

[0009] In order to solve the above problems, according to one aspect of the present disclosure, the present disclosure provides a fire-proof battery module, including: a plurality of battery cells arranged at intervals; a fire-proof spacing structure distributed in the gaps between the plurality of battery cells to block heat transfer between adjacent battery cells; fire-extinguishing microcapsules arranged at the positive electrodes of the battery cells to extinguish fires at the positive electrodes of the battery cells; and two fire-proof plates arranged side by side, with the plurality of battery cells, the fire-proof spacing structure and the fire-extinguishing microcapsules all located between the two fire-proof plates.

[0010] Furthermore, multiple battery cells are arranged in multiple rows and columns, and the fireproof partition structure includes multiple horizontal fireproof plates and multiple vertical fireproof plates. The multiple horizontal fireproof plates and multiple vertical fireproof plates are cross-arranged to separate and form multiple partition cavities, each of which has a battery cell.

[0011] Furthermore, the horizontal fireproofing sheet has a first slot, and the vertical fireproofing sheet has a second slot. The vertical fireproofing sheet is inserted into the first slot and the horizontal fireproofing sheet is inserted into the second slot to achieve connection.

[0012] Furthermore, the length of the transverse fireproof sheet is greater than that of the longitudinal fireproof sheet, and the end of the transverse fireproof sheet forms a flange, and there is a battery core in the area between the flange and the adjacent longitudinal fireproof sheet.

[0013] Furthermore, the horizontal fireproof sheet is a multi-layer structure, including at least one layer of laminated mica layer and at least one layer of reinforced glass cloth layer. The thickness of the horizontal fireproof sheet is 0.5mm to 1.5mm, and the material of the longitudinal fireproof sheet is the same as that of the horizontal fireproof sheet.

[0014] Furthermore, the positive poles of some battery cells face one fireproof board, and the positive poles of other battery cells face another fireproof board; there are multiple fire-extinguishing microcapsules, and the multiple fire-extinguishing microcapsules are distributed on both sides of the multiple battery cells, and the positions and shapes of the multiple fire-extinguishing microcapsules match the distribution positions of the positive poles of the multiple battery cells.

[0015] Furthermore, each fire extinguishing microcapsule covers the positive electrodes of at least two battery cells, and the fire extinguishing microcapsule is bonded to the positive electrodes of the battery cells.

[0016] Furthermore, the fire extinguishing microcapsules are sheets formed of perfluorohexanone, and the thickness of the fire extinguishing microcapsules is 1.5 mm to 3.5 mm.

[0017] Furthermore, a plurality of exhaust holes are distributed on the fireproof board, and the fireproof board is fixed by bonding.

[0018] Furthermore, the material of the fireproof board is glass fiber, and the thickness of the fireproof board is 0.5mm to 1.5mm.

[0019] Furthermore, the fireproof battery module also includes a first bracket and a second bracket connected to each other, the first bracket and the second bracket are both located between two fireproof boards, the fireproof partition structure and the multiple battery cells are both located in the first bracket and the second bracket, and the fireproof partition structure is bonded to at least one of the first bracket and the second bracket.

[0020] According to another aspect of the present disclosure, a battery module is provided, comprising a housing and the above-mentioned fireproof battery module, wherein the number of the fireproof battery modules is multiple and the multiple fireproof battery modules are arranged side by side in the cavity of the housing.

[0021] The technical solution of this disclosure provides a fireproof battery module. The fireproof battery module includes multiple spaced battery cells, a fireproof spacing structure, fire-extinguishing microcapsules, and two side-by-side fireproof panels. The fireproof spacing structure is distributed in the gaps between the multiple battery cells to block heat transfer between adjacent battery cells. The fire-extinguishing microcapsules are arranged at the positive electrodes of the battery cells to extinguish fires at the positive electrodes of the battery cells. The multiple battery cells, the fireproof spacing structure, and the fire-extinguishing microcapsules are all located between the two fireproof panels. Once a battery cell experiences thermal runaway, the positive electrode of the battery cell will first release gas, which is a flammable gas and can produce flames. Because this solution places fire-extinguishing microcapsules at the positive electrode of the battery cell, when a flame occurs at the positive electrode, the fire-extinguishing microcapsules are triggered to extinguish the fire. Fire-proof partitions are placed between the battery cells to separate them. When a cell experiences thermal runaway, the fire-proof partitions isolate the cell in a separate space, preventing the thermal runaway from spreading to other adjacent cells. Furthermore, fire-proof panels are placed on both sides of the multiple cells, preventing the flames within the module from escaping. Therefore, this solution forms a fire-extinguishing and fire-proof structure for the module through the design of these three components, thereby improving the fire resistance of the battery module and meeting higher safety requirements. BRIEF DESCRIPTION OF THE DRAWINGS

[0022] The accompanying drawings, which constitute part of this application, are intended to provide a further understanding of the present disclosure. The exemplary embodiments and descriptions of the present disclosure are intended to explain the present disclosure and do not constitute an improper limitation of the present disclosure. In the accompanying drawings:

[0023] FIG1 shows a schematic structural diagram of a fireproof battery module provided by an embodiment of the present disclosure;

[0024] FIG2 shows an exploded view of the fireproof battery module in FIG1 ;

[0025] FIG3 shows a schematic diagram of the fire separation structure in FIG2 ;

[0026] FIG4 shows a schematic structural diagram of a battery module provided by an embodiment of the present disclosure;

[0027] FIG5 is a schematic diagram showing the internal structure of FIG4 .

[0028] The above drawings include the following reference numerals:

[0029] 10. Battery cell; 20. Fireproof partition structure; 21. Horizontal fireproof sheet; 211. Flanged edge; 22. Vertical fireproof sheet; 30. Fire-extinguishing microcapsule; 40. Fireproof board; 41. Exhaust hole; 51. First bracket; 52. Second bracket; 60. Casing. DETAILED DESCRIPTION

[0030] The technical solutions in the embodiments of the present disclosure will be clearly and completely described below in conjunction with the drawings in the embodiments of the present disclosure. Obviously, the described embodiments are only some embodiments of the present disclosure, rather than all embodiments. The following description of at least one exemplary embodiment is actually only illustrative and is in no way intended to limit the present disclosure and its application or use. Based on the embodiments in the present disclosure, all other embodiments obtained by ordinary technicians in this field without making creative work are within the scope of protection of the present disclosure.

[0031] As shown in Figures 1 to 3, an embodiment of the present disclosure provides a fireproof battery module, including: a plurality of battery cells 10 arranged at intervals; a fireproof spacing structure 20, distributed in the gaps between the plurality of battery cells 10 to block heat transfer between adjacent battery cells 10; a fire-extinguishing microcapsule 30, arranged at the positive electrode of the battery cell 10 to extinguish the fire of the positive electrode of the battery cell 10; two fireproof plates 40 arranged side by side, and the plurality of battery cells 10, the fireproof spacing structure 20 and the fire-extinguishing microcapsule 30 are all located between the two fireproof plates 40.

[0032] Once a battery cell in a battery module experiences thermal runaway, the positive electrode of the battery cell will first release gas, and this gas is a flammable gas that may produce flames. Since a fire-extinguishing microcapsule 30 is arranged at the positive electrode of the battery cell 10 in this solution, when a flame is generated at the positive electrode of the battery cell 10, the fire-extinguishing microcapsule 30 is triggered to extinguish the fire; a fire-proof partition structure 20 is arranged between the battery cells 10 to separate the multiple battery cells 10. When a battery cell 10 experiences thermal runaway, the fire-proof partition structure 20 will isolate the thermally runaway battery cell 10 in a separate space, preventing the thermal runaway from being transmitted to other adjacent battery cells 10; and a fire-proof plate 40 is arranged on both sides of the multiple battery cells 10, thereby preventing the flames in the module from spreading outward. Therefore, this solution forms a fire-extinguishing and fire-proof structure of the module through the design of the above three parts, thereby improving the fire resistance of the battery module and meeting higher safety requirements.

[0033] The battery cells 10 are ternary 18650 lithium-ion battery cells, which are connected in parallel and in series. Of course, other types or specifications of battery cells can also be used as needed.

[0034] In this embodiment, multiple battery cells 10 are arranged in multiple rows and columns. The fireproof partition structure 20 includes multiple horizontal fireproof sheets 21 and multiple vertical fireproof sheets 22. The multiple horizontal fireproof sheets 21 and multiple vertical fireproof sheets 22 are arranged in an intersecting manner to form multiple compartments, each of which contains a battery cell 10. This arrangement facilitates the arrangement and connection of multiple battery cells 10 and provides a compact structure. The intersecting horizontal fireproof sheets 21 and multiple vertical fireproof sheets 22 form multiple compartments, each of which contains a battery cell 10. This allows each battery cell 10 to be located in a separate space, preventing the spread of thermal runaway.

[0035] Specifically, the horizontal fireproofing sheet 21 has a first slot, and the vertical fireproofing sheet 22 has a second slot. The openings of the first slot and the second slot are arranged in opposite directions. The vertical fireproofing sheet 22 is inserted into the first slot and the horizontal fireproofing sheet 21 is inserted into the second slot to achieve connection. In this way, the connection and cross arrangement of multiple horizontal fireproofing sheets 21 and multiple vertical fireproofing sheets 22 are achieved through plug-in connection, which facilitates assembly.

[0036] In this embodiment, the length of the horizontal fireproof sheet 21 is greater than that of the vertical fireproof sheet 22. The end of the horizontal fireproof sheet 21 forms a flange 211. A battery cell 10 is located in the area between the flange 211 and the adjacent vertical fireproof sheet 22. The area between the flange 211 and the adjacent vertical fireproof sheet 22 also forms a spacer cavity, thereby isolating the battery cells 10 at the end of the fireproof battery module.

[0037] Specifically, the horizontal fireproofing sheet 21 is a multi-layer structure, comprising at least one laminated mica layer and at least one reinforced glass cloth layer. The thickness of the horizontal fireproofing sheet 21 ranges from 0.5mm to 1.5mm. The longitudinal fireproofing sheet 22 is made of the same material as the horizontal fireproofing sheet 21. This arrangement ensures that the horizontal and longitudinal fireproofing sheets 21 and 22 provide excellent fire protection without taking up excessive space. Both the horizontal and longitudinal fireproofing sheets 21 and 22 are temperature-resistant up to 700°C.

[0038] In this embodiment, the positive electrodes of some battery cells 10 face one fireproof plate 40, while the positive electrodes of other battery cells 10 face another fireproof plate 40. Multiple fire-extinguishing microcapsules 30 are provided, distributed on both sides of the battery cells 10. The positions and shapes of the multiple fire-extinguishing microcapsules 30 match the distribution of the positive electrodes of the battery cells 10. In other words, the multiple fire-extinguishing microcapsules 30 in this embodiment are distributed according to the distribution of the positive electrodes of the battery cells 10, thereby promptly extinguishing fires at the positive electrodes of the battery cells 10.

[0039] Specifically, each fire-extinguishing microcapsule 30 covers the positive electrodes of at least two battery cells 10, reducing the number of fire-extinguishing microcapsules 30 and improving assembly efficiency. The fire-extinguishing microcapsules 30 are bonded to the positive electrodes of the battery cells 10 using an adhesive method, which is convenient and highly reliable. The fire-extinguishing microcapsules 30 can be shaped like a cross, a straight line, or a U.

[0040] In this embodiment, the fire extinguishing microcapsules 30 are sheets made of perfluorohexanone, and the thickness of the fire extinguishing microcapsules 30 is 1.5 mm to 3.5 mm. This material can achieve a good fire extinguishing effect.

[0041] The fireproof plate 40 is provided with a plurality of exhaust holes 41, which are fixed by bonding. The exhaust holes 41 are used to discharge the gas generated when the battery cell experiences thermal runaway, so as to dissipate heat and relieve pressure.

[0042] Specifically, the fireproof board 40 is made of glass fiber, and the thickness of the fireproof board 40 is 0.5 mm to 1.5 mm. Glass fiber material has good fire resistance and low cost.

[0043] Furthermore, the fireproof battery module also includes a first bracket 51 and a second bracket 52 that are interconnected. Both the first bracket 51 and the second bracket 52 are located between the two fireproof panels 40. The fireproof spacing structure 20 and the plurality of battery cells 10 are located within the first bracket 51 and the second bracket 52. The fireproof spacing structure 20 is bonded to at least one of the first bracket 51 and the second bracket 52. A space is formed between the first bracket 51 and the second bracket 52 to accommodate the battery cells 10 and to support and secure the battery cells 10. Bonding the fireproof spacing structure 20 to at least one of the first bracket 51 and the second bracket 52 can secure the fireproof spacing structure 20 and prevent it from deviating from its position.

[0044] As shown in Figures 4 and 5, the present solution also provides a battery module, which includes a shell 60 and the above-mentioned fireproof battery module. There are multiple fireproof battery modules, and the multiple fireproof battery modules are arranged side by side in the cavity of the shell 60. Since the fire extinguishing microcapsules 30 are arranged at the positive pole of the battery cell 10 in this solution, when a flame is generated at the positive pole position of the battery cell 10, the fire extinguishing microcapsules 30 are triggered to extinguish the fire; a fireproof partition structure 20 is arranged between the battery cells 10 to separate the multiple battery cells 10. When a battery cell 10 thermally runs away, the fireproof partition structure 20 will isolate the thermally runaway battery cell 10 in a separate space, preventing the thermal runaway from being transmitted to other adjacent battery cells 10; and a fireproof plate 40 is arranged on both sides of the multiple battery cells 10, thereby preventing the flames in the module from spreading out. Therefore, the present solution forms a fire extinguishing and fireproof structure of the module through the design of the above three parts, thereby improving the fireproof performance of the battery module and the battery module, and meeting higher safety requirements.

[0045] The multiple fireproof battery modules of the battery module are connected by copper bars, and each module is fixed in the housing 60 by screws.

[0046] In this solution, based on the conventional application solution of lithium iron phosphate system at the cabinet level in the UPS backup power industry, we focus on the key and difficult issues in the ternary lithium battery fire prevention and fire extinguishing industry, and design at the module level or even smaller module units to ensure that the final product application meets market and customer requirements.

[0047] This solution uses fire protection design at the module level and between smaller module units and 18650 battery cells. At the same time, fire extinguishing microcapsules are arranged in smaller module units to extinguish flames as soon as they appear after thermal runaway. At the same time, fire barrier design is implemented between smaller module units after thermal runaway to prevent the spread of fire between module units.

[0048] The specific design principle is: the battery cells we use are ternary 18650 lithium-ion battery cells. The battery cells are combined in parallel and series, and then fixed and shaped by plastic brackets. In order to facilitate the combination design, the positive and negative poles of the battery cells are connected in series and parallel on the upper and lower sides of the plastic bracket. Once a battery cell experiences thermal runaway, the positive electrode air vent of the battery cell will first release gas, which is a flammable gas and may produce flames. We have arranged sheet-shaped fire-extinguishing microcapsules above the positive electrode air vent of the battery cell. When a flame is generated at the battery cell air vent position, the fire-extinguishing microcapsules are triggered to extinguish the fire. At the same time, we reserve a certain gap between the battery cells and arrange mica fireproof sheets to form "battery cell wells" between the plastic module brackets. When a battery cell experiences thermal runaway, the "battery cell well" formed by the mica fireproof sheets between the battery cells will isolate the thermally runaway battery cell in its own unique "battery cell well", thereby preventing the thermal runaway of the battery cell. In addition, a glass fiber insulation board is arranged on the upper and lower sides of the plastic bracket for fire prevention, thereby preventing the flames in the module from escaping. The design of the above three parts forms a fire extinguishing and fireproofing structure of the module to meet product requirements.

[0049] The above are merely preferred embodiments of the present disclosure and are not intended to limit the present disclosure. Those skilled in the art will readily appreciate that various modifications and variations of the present disclosure are possible. Any modifications, equivalent substitutions, or improvements made within the spirit and principles of the present disclosure shall be included within the scope of protection of the present disclosure.

Claims

1. A fireproof battery module, characterized in that: include: A plurality of battery cells (10) arranged at intervals; A fireproof spacing structure (20) is distributed in the gaps between the plurality of battery cells (10) to block heat transfer between adjacent battery cells (10); A fire extinguishing microcapsule (30) is arranged at the positive electrode of the battery cell (10) to extinguish the fire at the positive electrode of the battery cell (10); Two fireproof boards (40) are arranged side by side, and the plurality of battery cells (10), the fireproof spacing structure (20) and the fire-extinguishing microcapsules (30) are all located between the two fireproof boards (40).

2. The fireproof battery module according to claim 1, characterized in that: The plurality of battery cells (10) are arranged in a plurality of rows and columns, and the fireproof partition structure (20) comprises a plurality of transverse fireproof sheets (21) and a plurality of longitudinal fireproof sheets (22). The plurality of transverse fireproof sheets (21) and the plurality of longitudinal fireproof sheets (22) are cross-arranged to separate and form a plurality of partition cavities, each of which contains a battery cell (10).

3. The fireproof battery module according to claim 2, characterized in that: The transverse fireproof sheet (21) has a first slot, and the longitudinal fireproof sheet (22) has a second slot. The longitudinal fireproof sheet (22) is inserted into the first slot and the transverse fireproof sheet (21) is inserted into the second slot to achieve connection.

4. The fireproof battery module according to claim 2, characterized in that: The length of the transverse fireproof sheet (21) is greater than the length of the longitudinal fireproof sheet (22), and the end of the transverse fireproof sheet (21) forms a flange (211), and a battery cell (10) is provided in the area between the flange (211) and the adjacent longitudinal fireproof sheet (22).

5. The fireproof battery module according to claim 2, characterized in that: The transverse fireproof sheet (21) is a multi-layer structure, comprising at least one layer of laminated mica and at least one layer of reinforced glass cloth. The thickness of the transverse fireproof sheet (21) is 0.5 mm to 1.5 mm. The material of the longitudinal fireproof sheet (22) is the same as that of the transverse fireproof sheet (21).

6. The fireproof battery module according to claim 1, characterized in that: The positive electrodes of a portion of the battery cells (10) face one of the fireproof boards (40), while the positive electrodes of another portion of the battery cells (10) face another of the fireproof boards (40); there are a plurality of fire-extinguishing microcapsules (30), and the plurality of fire-extinguishing microcapsules (30) are distributed on both sides of the plurality of battery cells (10); the positions and shapes of the plurality of fire-extinguishing microcapsules (30) match the distribution positions of the positive electrodes of the plurality of battery cells (10).

7. The fireproof battery module according to claim 1, characterized in that: Each of the fire extinguishing microcapsules (30) covers the positive electrodes of at least two of the battery cells (10), and the fire extinguishing microcapsules (30) are bonded to the positive electrodes of the battery cells (10).

8. The fireproof battery module according to claim 1, characterized in that: The fire extinguishing microcapsule (30) is a sheet material formed of perfluorohexanone, and the thickness of the fire extinguishing microcapsule (30) is 1.5 mm to 3.5 mm.

9. The fireproof battery module according to claim 1, characterized in that: A plurality of exhaust holes (41) are distributed on the fireproof board (40), and the fireproof board (40) is fixed by bonding.

10. The fireproof battery module according to claim 1, characterized in that: The material of the fireproof board (40) is glass fiber, and the thickness of the fireproof board (40) is 0.5 mm to 1.5 mm.

11. The fireproof battery module according to claim 1, characterized in that: The fireproof battery module also includes a first bracket (51) and a second bracket (52) that are interconnected, the first bracket (51) and the second bracket (52) are both located between the two fireproof panels (40), the fireproof spacing structure (20) and the plurality of battery cells (10) are both located within the first bracket (51) and the second bracket (52), and the fireproof spacing structure (20) is bonded to at least one of the first bracket (51) and the second bracket (52).

12. A battery module, characterized in that: The battery module comprises a housing (60) and a fireproof battery module according to any one of claims 1 to 11, wherein there are a plurality of fireproof battery modules, and the plurality of fireproof battery modules are arranged side by side in the cavity of the housing (60).

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