Battery pack and energy storage equipment
By setting a heating film inside the battery pack and adjusting the wiring density of the heating wire, consistent control of the cell temperature was achieved, solving the problem of large temperature differences among cells in low-temperature environments and improving the battery pack's lifespan and safety.
Patent Information
- Application Number
- CN202520235316.2
- Authority / Receiving Office
- CN · China
- Patent Type
- Utility models(China)
- Current Assignee / Owner
- Filing Date
- 2025-02-14
- Publication Date
- 2026-01-09
- Estimated Expiration
- 2035-02-14
AI Technical Summary
In low-temperature environments, the temperature differences between the cells within the battery pack are significant, leading to a shortened cell lifespan and reduced safety.
By setting a heating film inside the battery pack and adjusting the wiring density of the heating wires so that the density in the middle part of the heating film is less than that at both ends, the uniformity of the cell temperature is ensured. A differentiated heating design is adopted to control the cell temperature within a preset range.
It improves the charging and discharging efficiency of the battery pack, extends the battery pack's lifespan and safety performance, and reduces the risk of thermal runaway.
Smart Images
Figure CN223785200U_ABST
Abstract
Description
TECHNICAL FIELD
[0001] The present application relates to the technical field of energy storage, and in particular to a battery pack and an energy storage device. BACKGROUND
[0002] In the related art, in a low-temperature working environment, a plurality of battery cells in a battery pack are heated by a heating film to provide a temperature of a working environment of the battery pack, so as to improve the charging and discharging efficiency of the battery pack. However, the arrangement of the heating film in the related art causes a large temperature difference between the plurality of battery cells in the battery pack, and the consistency is poor. This not only affects the service life of the battery cells, but also may cause thermal runaway of the battery cells, thereby reducing the service life and safety of the battery pack. SUMMARY
[0003] Embodiments of the present application provide a battery pack and an energy storage device to improve the service life and safety of the battery pack.
[0004] In a first aspect, embodiments of the present application provide a battery pack. The battery pack includes a shell, a plurality of battery cells arranged in the shell, and a heating film arranged in the shell. The plurality of battery cells are arranged along a first direction. The heating film is attached to the plurality of battery cells. The heating film extends to both ends of the plurality of battery cells in the first direction. The wiring density of the heating wire in the middle part of the heating film is less than the wiring density of the heating wire at both ends of the heating film in the first direction. In the first direction, the heat dissipation effect of the battery cells at both ends of the plurality of battery cells is good, and the heat dissipation effect of the battery cells in the middle part of the plurality of battery cells is poor. Therefore, by setting the wiring density of the heating wire in the middle part of the heating film to be less than the wiring density of the heating wire at both ends of the heating film in the first direction, the greater the sealing of the heating wire, the stronger the heating efficiency of the heating film, and the smaller the sealing of the heating wire, the poorer the heating efficiency of the heating film. Since the density of the heating wire in the middle part of the heating film is small, the battery cells in the middle part are less affected by the heating film. The density of the heating wire at both ends of the heating film is large, so that the battery cells at both ends can obtain stronger heating efficiency of the heating film. Therefore, the battery cells with poor heat dissipation effect can obtain smaller heating efficiency, and the battery cells with good heat dissipation effect can obtain stronger heating efficiency of the heating film. Thus, the temperature difference between the plurality of battery cells can be effectively reduced, the temperature consistency of the plurality of battery cells is better, and the service life and safety of the battery pack can be effectively improved.
[0005] In some embodiments, the heating film is used to keep the plurality of battery cells within a preset temperature range, and the temperature difference between the plurality of battery cells is less than a threshold value. Since the heating film can keep the plurality of battery cells within a preset temperature range, it can effectively improve the charging and discharging efficiency of the battery pack. Moreover, the temperature difference between the plurality of battery cells can be less than a threshold value to avoid a large temperature difference between the plurality of battery cells, thereby avoiding a situation where a low-temperature battery cell reaches the target temperature while a high-temperature battery cell has a temperature that is too high. This can prevent the short board effect in the battery pack caused by a large temperature difference between the battery cells, thereby reducing the impact on the performance and service life of the battery pack and possibly reducing the safety hazards such as thermal runaway of the battery pack. In summary, the battery pack of the present embodiment can effectively improve the service life and safety performance of the battery pack while ensuring the charging and discharging efficiency.
[0006] In some embodiments, the heating film includes a plurality of regions arranged along a first direction, the plurality of regions including a first region and second and third regions located on both sides of the first region, the first region corresponding to a middle portion of the heating film, the second and third regions corresponding to both ends of the heating film, the wiring density of the heating wires in the first region being less than the wiring density of the heating wires in the second region and the wiring density of the heating wires in the third region, respectively, and the wiring density of the heating wires in the second region being less than the wiring density of the heating wires in the third region. By designing the wiring density of the heating wires in the third region to be greater than the wiring density of the heating wires in the second region, the heating efficiency of the heating wires in the third region is greater than the heating efficiency of the heating wires in the second region. By differentiating the heating efficiency of the heating wires in the third region and the heating efficiency of the heating wires in the second region, the uniformity of the temperature of the different battery cells in the battery pack after being heated by the heating film can be effectively ensured after the plurality of battery packs are arranged in close proximity in the cabinet.
[0007] In some embodiments, the first region is used to heat a first battery cell in the plurality of battery cells, i.e., the first battery cell is arranged in the first region, the second region is used to heat a second battery cell in the plurality of battery cells, i.e., the second battery cell is arranged in the second region, and the third region is used to heat a third battery cell in the plurality of battery cells, i.e., the third battery cell is arranged in the third region, and the first battery cell is located between the second and third battery cells in the first direction. By differentiating the heating of different battery cells in different regions, the temperature of different battery cells can be accurately controlled, which can effectively improve the uniformity of the plurality of battery cells and thereby improve the service life and safety performance of the battery pack.
[0008] In some embodiments, the first region includes a fourth region and a fifth region arranged along the first direction, the fourth region is located at a side of the fifth region close to the second region, and the wiring density of the heating wires of the fifth region is greater than the wiring density of the heating wires of the fourth region. Since the second regions of the two adjacent battery packs are close to each other at one end in the first direction, the heat dissipation effect of the corresponding end of the second region is poor, so the heat dissipation effect of the corresponding battery cell of the fourth region adjacent to the second region is lower than that of the fifth region adjacent to the third region. In order to ensure the uniformity of the temperature of the battery cell corresponding to the fourth region and the battery cell corresponding to the fifth region after being heated, the wiring density of the heating wires of the fifth region is greater than the wiring density of the heating wires of the fourth region, so that the battery cell corresponding to the fourth region and the battery cell corresponding to the fifth region can be heated differently, so that the temperature difference between the battery cell corresponding to the fourth region and the battery cell corresponding to the fifth region after being heated is controlled within a threshold, so as to improve the uniformity of the plurality of battery cells and improve the service life and safety performance of the battery pack.
[0009] In some embodiments, the heating wires of the first region, the heating wires of the second region, and the heating wires of the third region are connected in series. That is, the heating wires corresponding to the positions of the first battery cells, the heating wires corresponding to the positions of the second battery cells, the heating wires corresponding to the positions of the third battery cells, and the heating wires corresponding to the positions of the plurality of fourth battery cells are connected in series. Since the heating wires of the first region, the heating wires of the second region, and the heating wires of the third region are connected in series, the same current flows through the heating wires of the first region, the heating wires of the second region, and the heating wires of the third region, so as to effectively and accurately control the heating power of each region and improve the uniformity of the plurality of battery cells after being heated.
[0010] In some embodiments, the heating wires of the first region, the heating wires of the second region, and the heating wires of the third region are connected in parallel, that is, the heating wires corresponding to the positions of the first battery cells, the heating wires corresponding to the positions of the second battery cells, the heating wires corresponding to the positions of the third battery cells, and the heating wires corresponding to the positions of the plurality of fourth battery cells are connected in parallel. Since the heating wires of the first region, the heating wires of the second region, and the heating wires of the third region are connected in parallel, the heating wires of the first region, the heating wires of the second region, and the heating wires of the third region can be independently controlled, so as to reasonably heat different battery cells according to needs.
[0011] In some embodiments, the heating wires of the heating film are uniformly arranged in a second direction, and the second direction is perpendicular to the first direction. That is, the heating wires of the first region are uniformly arranged in the second direction, the heating wires of the second region are uniformly arranged in the second direction, and the heating wires of the third region are uniformly arranged in the second direction. Since the heating wires of the heating film are uniformly arranged in the second direction, the power of the heating wires of each region can be calculated conveniently, and the uniform heating of the battery cells can be improved by uniformly arranging the heating wires of the heating film in the second direction.
[0012] In some embodiments, the density of the heating wires of the heating film gradually increases from the middle part of the heating film to any end of the heating film in the first direction. Since the heat dissipation effect of the battery cells located in the middle part is the worst, and the heat dissipation effect of the battery cells located at the two ends is the best, and the heat dissipation effect gradually changes, the density of the heating wires of the heating film gradually increases from the middle part of the heating film to any end of the heating film in the first direction. The temperature of the battery cells can be controlled more accurately, and the uniform heating of the battery cells is better.
[0013] In some embodiments, the heating film is arranged between the side plate of the shell and the battery cells. By arranging the heating film between the side plate of the shell and the battery cells, the heating film can not only heat the battery cells, but also insulate the battery cells and the side plate by the insulating heat-conducting layer of the heating film. Thus, the heating film has two functions, and the function of the battery pack is increased without complicating the structure of the battery pack.
[0014] In some embodiments, the heating film is arranged between the bottom plate of the shell and the battery cells. By arranging the heating film between the bottom plate of the shell and the battery cells, the heating film can not only heat the battery cells, but also insulate the battery cells and the bottom plate by the insulating heat-conducting layer of the heating film. Thus, the heating film has two functions, and the function of the battery pack is increased without complicating the structure of the battery pack.
[0015] In some embodiments, the battery pack further comprises a heat insulation film arranged between the heating film and the shell. By arranging the heat insulation film between the heating film and the shell, the heat generated by the heating film can be effectively prevented from being released from the shell, and the battery cells can be heated more effectively, the heating efficiency of the battery cells is improved, and the initial preset power of the heating film is reduced.
[0016] In a second aspect, the embodiments of the present application provide a power storage device, which comprises a cabinet and a plurality of battery packs according to any one of the battery packs in the first aspect.
[0017] In some embodiments, the heating film comprises a second region and a third region opposite in the first direction, i.e., the regions corresponding to the two ends of the heating film in the first direction are the second region and the third region respectively, the wiring density of the heating wire of the second region is less than the wiring density of the heating wire of the third region, two adjacent first battery packs are arranged along the first direction, and in the two heating films in the two adjacent battery packs, the two second regions are located between the two third regions in the first direction, i.e., the two second regions of the adjacent two battery packs are close to each other. Since the two second regions of the adjacent two battery packs are close to each other, and the wiring density of the heating wire of the second region is less than the wiring density of the heating wire of the third region, the heating efficiency of the second region is less than that of the third region. Since the two second regions of the adjacent two battery packs are close to each other, the heat dissipation effect of the two second regions of the adjacent two battery packs will be poor. By the poor heating efficiency of the second region, the second region corresponding to the battery cell is heated, and by the good heating efficiency of the third region, the third region corresponding to the battery cell is heated. Therefore, the temperature uniformity of the battery cell corresponding to the second region and the battery cell corresponding to the third region can be effectively improved, so as to improve the service life and safety of the battery pack. BRIEF DESCRIPTION OF DRAWINGS
[0018] In order to more clearly illustrate the technical solutions in the embodiments of the present application or the prior art, the drawings needed to be used in the embodiments or prior art description will be briefly introduced as follows.
[0019] Figure 1 An embodiment provides a structural schematic diagram of an energy storage device;
[0020] Figure 2 A structural schematic diagram of a battery pack is provided for an embodiment of the present application;
[0021] Figure 3 For Figure 2 A decomposition schematic diagram of a heating film in an embodiment;
[0022] Figure 4 For Figure 2 A wiring schematic diagram of a heating wire in a heating film in an embodiment;
[0023] Figure 5A A temperature simulation schematic diagram of battery cells at different positions in a battery pack when the heating film is not started;
[0024] Figure 5B For Figure 5A A temperature simulation schematic diagram when the battery pack heating film in the embodiment is started;
[0025] Figure 6 A schematic diagram of one arrangement mode of a plurality of battery packs is shown;
[0026] Figure 7Another schematic diagram of a wiring mode of a heating wire of a heating film provided by an embodiment of the present application.
[0027] Explanation of reference signs:
[0028] X, first direction; Y, second direction;
[0029] 1, energy storage device; 2, cabinet body; 3, battery pack;
[0030] 10, shell; 11, end plate; 12, side plate; 13, bottom plate;
[0031] 20, battery cell; 21, first battery cell; 22, second battery cell; 23, third battery cell;
[0032] 30, heating film; 31, heat conduction layer; 32, reinforcing layer; 33, heating wire; 34, first area; 35, second area; 36, third area; 37, fourth area; 38, fifth area;
[0033] 40, heat insulation film. DETAILED DESCRIPTION
[0034] The following first explains some terms related to the embodiments of the present application.
[0035] The terms "first", "second", "third", "fourth" and the like in the description, claims, and drawings of the embodiments of the present application are used to distinguish similar objects, and do not necessarily have to be used to describe a particular sequential or chronological order. It should be understood that the terms so used are interchangeable under appropriate circumstances and that the embodiments of the present application described herein are capable of functioning in other sequences than the one explicitly described or illustrated herein. Furthermore, the terms "comprise", "comprising", "include", "including", and the like are intended to cover non-exclusive inclusions, such that processes, methods, articles, or apparatuses that comprise, include, or the like a list of steps or elements are not necessarily limited to those steps or elements specifically listed, but can include additional steps or elements not expressly listed or inherent to such processes, methods, articles, or apparatuses.
[0036] In the present specification, the explanation of the terms "vertical" and the like.
[0037] Vertical: The vertical defined in the present application is not limited to an absolutely vertical intersection (an angle of 90 degrees) relationship, and allows a relationship that is not an absolutely vertical intersection due to factors such as assembly tolerances, design tolerances, and structure flatness, and allows a small angle range of error, for example, an assembly error range of 80 degrees to 100 degrees, to be understood as a vertical relationship.
[0038] In modern society, there are a large number of devices that rely on electricity to operate, from household appliances to data centers and factory production lines. Power supply is one of the factors that maintain the normal operation of modern society. Therefore, energy storage devices are rapidly developing and widely used, such as battery packs, energy storage cabinets using battery packs, power cabinets of data centers, and even vehicles using battery packs. Energy storage devices can be used to store electrical energy and power devices that need to operate on electricity. Energy storage devices can be applied in the fields of site energy, photovoltaic, household energy storage, industrial and commercial energy storage, large ground power station energy storage, etc.
[0039] As the core part of the energy storage device, the battery pack determines the performance and service life of the energy storage device. In the related art, the battery pack has low charging and discharging efficiency in a low-temperature working environment, which reduces the charging and discharging performance of the energy storage device. In order to improve the charging and discharging efficiency of the battery pack in a low-temperature environment, in some embodiments, a heating film is used to heat a plurality of battery cells in the battery pack to provide a temperature of the working environment of the battery pack, so as to improve the charging and discharging efficiency of the battery pack. However, the setting of the heating film can effectively improve the charging and discharging efficiency of the battery pack to a certain extent, but it can cause a large temperature difference between the plurality of battery cells in the battery pack. Moreover, the longer the working time of the heating film, the greater the temperature difference between the plurality of battery cells, which can cause the temperature of the high-temperature battery cell to be too high when the low-temperature battery cell reaches the target temperature. This not only affects the service life of the battery cell, but also can cause thermal runaway of the battery cell, thereby reducing the service life and safety of the battery pack, and further reducing the service life and safety of the energy storage device.
[0040] In order to improve the service life and safety of the energy storage device 1, with reference to Figure 1 , Figure 1The embodiment provides a structural diagram of an energy storage device 1, the energy storage device 1 comprising a cabinet 2 and a plurality of battery packs 3 arranged in the cabinet 2, and the plurality of battery packs 3 are stacked in the cabinet 2. In the embodiment, the battery pack 3 is provided with a heating film (not shown in the figure) in the battery pack 3, so as to improve the working environment temperature of the battery cell in the battery pack 3, and the wiring density of the heating wire at different positions of the heating film is controlled, so as to control the heating efficiency at different positions of the heating film, and then the battery cells at different positions are selectively heated to different degrees, so that the different battery cells in the battery pack 3 can be heated to a preset temperature range, that is, the temperature of the different battery cells in the battery pack 3 can not be too low to cause insufficient charging and discharging efficiency, and can not be too high to affect the service life or safety performance of the battery cell. For example, the wiring density of the heating wire at the position corresponding to the battery cell at the position where the heating film and the heat dissipation effect are better is adjusted to increase the heating efficiency of the battery cell at the position where the heat dissipation effect is better, and the wiring density of the heating wire at the position corresponding to the battery cell at the position where the heating film and the heat dissipation effect are worse is adjusted to reduce the heating efficiency of the battery cell at the position where the heat dissipation effect is worse, so that the working temperature of the plurality of battery cells in the battery pack 3 can reach the preset temperature range, so as to effectively improve the service life and safety performance of the battery pack 3 under the premise of ensuring the charging and discharging efficiency of the battery pack 3, and then the service life and safety of the energy storage device 1 are improved.
[0041] Figure 2 A structural diagram of a battery pack 3 is provided in the embodiment, and the top plate of the shell 10 is hidden in the embodiment for the convenience of showing more features.
[0042] Reference Figure 2 In some embodiments, the battery pack 3 comprises a shell 10, a plurality of battery cells 20 and a heating film 30.
[0043] The shell 10 comprises two end plates 11 opposite in the length direction of the battery pack 3, two side plates 12 opposite in the width direction of the battery pack 3, and a top plate and a bottom plate 13 opposite in the height direction of the battery pack 3, the two end plates 11 and the two side plates 12 are connected between the top plate and the bottom plate 13, and together form an accommodating cavity, and the plurality of battery cells 20 and the heating film 30 are arranged in the accommodating cavity.
[0044] The plurality of battery cells 20 are arranged in the shell 10 along a first direction X, for example, in some embodiments, the first direction X is the length direction of the battery pack 3, and the plurality of battery cells 20 are arranged along the length direction of the battery pack 3. It can be understood that in some other embodiments, the first direction X can also be the width direction of the battery pack 3 or the height direction of the battery pack 3.
[0045] The heating film 30 is used to heat the plurality of battery cells 20, and make the plurality of battery cells 20 all heated to a preset temperature range, such as within 10-30℃. Specifically, the heating film 30 is attached to the plurality of battery cells 20, and the heating film 30 extends to both ends of the plurality of battery cells 20 along the first direction X, that is, the plurality of battery cells 20 can all be in effective contact with the heating film 30, so as to ensure that the plurality of battery cells 20 can all be heated by the heating film 30. The heating film 30 is used to make the battery cells 20 at different positions in the plurality of battery cells 20 have different heating efficiencies, so that the maximum temperature difference of the plurality of battery cells 20 is less than a threshold value, such as less than 6℃. Through the heating film 30 in the embodiment, the temperature of the plurality of battery cells 20 of the battery pack 3 after being heated can be kept within the expected temperature range, so as to avoid a large temperature difference between the plurality of battery cells 20. For example, when the battery cells 20 at low temperature reach the target temperature, the battery cells 20 at high temperature have a temperature that is too high. Therefore, the service life and safety performance of the battery pack 3 can be effectively improved under the premise of ensuring the charging and discharging efficiency of the battery pack 3.
[0046] In order to improve the heating efficiency of the heating film 30 on the battery cells 20, with reference to Figure 2 In some embodiments, the battery pack 3 further comprises a heat insulation film 40, which is arranged between the heating film 30 and the shell 10. By arranging the heat insulation film 40 between the heating film 30 and the shell 10, the heat generated by the heating film 30 can be effectively prevented from being released from the shell 10, and the battery cells 20 can be more effectively heated, the heating efficiency of the battery cells 20 is improved, and the initial preset power of the heating film 30 can be effectively reduced.
[0047] Figure 3 For Figure 2 The exploded view of the heating film 30 in the embodiment; Figure 4 For Figure 2 The wiring diagram of the heating wire 33 in the heating film 30 in the embodiment. Figure 5A The temperature simulation diagram of the battery cells 20 at different positions in the battery pack 3 when the heating film 30 is not started, Figure 5A The ambient temperature of the battery pack in the embodiment is 20℃; Figure 5B For Figure 5A The temperature simulation diagram of the battery pack 3 in the embodiment when the heating film 30 is started, taking the ambient temperature of minus 10℃ as an example.
[0048] With reference to Figure 3In some embodiments, the heating film 30 comprises, in sequence, a heat-conducting layer 31, a reinforcing layer 32, a heat-conducting layer 31, a heating wire 33, a heat-conducting layer 31, a reinforcing layer 32, and a heat-conducting layer 31. The heating wire 33 is used to heat the battery cell 20 by passing an electric current. The reinforcing layer 32 is arranged on both sides of the heating wire 33, which can be used to effectively fix the heating wire 33, so that the heating wire 33 can be kept at a desired set position, so that the heating film 30 can be maintained in a desired shape, which is conducive to the assembly of the heating film 30. The heat-conducting layer 31 is arranged on both sides of the reinforcing layer 32 and the heating wire 33, which not only can encapsulate the reinforcing layer 32 and the heating wire 33 to avoid the risk of electric leakage and short circuit, but also can effectively transfer the heat emitted by the heating wire 33 to the battery cell 20. It can be understood that in other embodiments, the heating film 30 can also not be provided with the reinforcing layer 32. The number of heat-conducting layers 31 can also be set according to requirements, such as one heat-conducting layer 31 arranged on each side of the heating wire 33.
[0049] In order to enable the battery cells 20 at different positions in the plurality of battery cells 20 to obtain different heating efficiencies of the heating film 30, with reference to Figure 3 and Figure 4 In the first direction X, the wiring density of the heating wire 33 of the middle part of the heating film 30 is less than the wiring density of the heating wire 33 of the two ends of the heating film 30, so as to ensure that the temperature of the plurality of battery cells 20 after being heated can be within a pre-set temperature range, and the maximum temperature difference of the plurality of battery cells 20 is less than a pre-set threshold. For example, Figure 5A is a schematic diagram of the heat dissipation effect of the battery cells 20 at different positions in the battery pack 3. In the first direction X, the heat dissipation effect of the battery cells 20 at the two ends of the plurality of battery cells 20 is good, while the heat dissipation effect of the battery cells 20 at the middle part is poor. Therefore, by arranging the wiring density of the heating wire 33 of the middle part of the heating film 30 to be less than the wiring density of the heating wire 33 of the two ends of the heating film 30 in the first direction X, the greater the sealing of the heating wire 33, the stronger the heating efficiency of the heating film 30, and the smaller the sealing of the heating wire 33, the poorer the heating efficiency of the heating film 30. Since the density of the heating wire 33 of the middle part of the heating film 30 is small, the battery cells 20 at the middle part are heated by the heating film 30 with poor effect, while the density of the heating wire 33 of the two ends of the heating film 30 is large, so that the battery cells 20 at the two ends can obtain stronger heating efficiency of the heating film 30. Therefore, the battery cells 20 with poor heat dissipation effect obtain smaller heating efficiency, and the battery cells 20 with good heat dissipation effect obtain stronger heating efficiency of the heating film 30. Through the reasonable arrangement of the heating wire 33 on the heating film 30, the temperature of the plurality of battery cells 20 of the battery pack 3 after being heated can be maintained within a desired temperature range (for example, Figure 5B ), so as to improve the charging and discharging efficiency of the battery pack 3. Moreover, the temperature consistency between the plurality of battery cells 20 can be improved (for example, Figure 5B), to avoid the case that the temperature of the low-temperature battery cell 20 is too high when the battery cell 20 reaches the target temperature, to avoid the short board effect in the battery pack 3 caused by the too large temperature difference between the battery cells 20, and to reduce the influence on the performance and service life of the battery pack 3, and possibly reduce the safety hazards such as thermal runaway of the battery pack 3. In summary, the battery pack 3 of the embodiment can effectively improve the service life and safety performance of the battery pack 3 under the premise of ensuring the charging and discharging efficiency.
[0050] It can be understood that the wiring density herein refers to the density of the heating wire 33 per unit area in the region. The greater the density of the heating wire 33 in the embodiment, the greater the heating power, and the smaller the density of the heating wire 33, the smaller the power of the heating wire 33. For example, in some embodiments, the thickness of the heating wire 33 at each position in the heating film 30 is substantially the same, so that the greater the density of the heating wire 33, the greater the heating power, and the smaller the density of the heating wire 33, the smaller the power of the heating wire 33.
[0051] Referring to Figure 4 In some embodiments, for convenience of description, it is assumed that the heating film 30 includes a plurality of regions arranged along the first direction X, such as a first region 34 with a smaller wiring density of the heating wire 33 and second and third regions 35 and 36 with a larger wiring density of the heating wire 33, wherein the first region 34 is located between the second and third regions 35 and 36 in the first direction X. For example, in some embodiments, the first region 34 is the middle part of the heating film 30 in the first direction X, and the second and third regions 35 and 36 are the two end parts of the heating film 30 in the first direction X. Since the wiring density of the heating wire 33 of the first region 34 is smaller than that of the second and third regions 35 and 36, the heating power of the first region 34 is smaller than that of the second and third regions 35 and 36.
[0052] For the convenience of description, the battery cell 20 attached to the first area 34 is set as the first battery cell 21, so as to heat the first battery cell 21 by the heating wire 33 of the first area 34. The battery cell 20 attached to the second area 35 is set as the second battery cell 22, so as to heat the second battery cell 22 by the heating wire 33 of the second area 35. Similarly, the battery cell 20 attached to the third area 36 is set as the third battery cell 23, so as to heat the third battery cell 23 by the heating wire 33 of the third area 36. In order to make the temperatures of the first battery cell 21, the second battery cell 22 and the third battery cell 23 after being heated by the heating film 30 all be within the preset temperature range, the first battery cell 21 is located between the second battery cell 22 and the third battery cell 23 in the first direction X, that is, the first battery cell 21 is located in the middle part of the plurality of battery cells 20, and the heat dissipation effect of the first battery cell 21 at this position is poor, so that the first battery cell 21 can be heated by the heating wire 33 of the first area 34 with low heating efficiency to reach the preset temperature range, and the risk of thermal runaway of the first battery cell 21 after being heated can be effectively avoided. The second battery cell 22 and the third battery cell 23 are located at two ends of the first battery cell 21, and then the second battery cell 22 and the third battery cell 23 are close to the two end plates 11 of the shell 10, and the heat dissipation effect is good, so that the second battery cell 22 can be heated by the heating wire 33 of the second area 35 with high heating efficiency, and the third battery cell 23 can be heated by the heating wire 33 of the third area 36 with high heating efficiency, so as to effectively ensure that the second battery cell 22 and the third battery cell 23 can be heated to the preset temperature range, so as to effectively improve the charge and discharge efficiency of the second battery cell 22 and the third battery cell 23. Moreover, since the second battery cell 22 and the third battery cell 23 have good heat dissipation, the second battery cell 22 and the third battery cell 23 can still avoid the risk of thermal runaway after being heated by the heating wires 33 of the second area 35 and the third area 36 with higher heating efficiency.
[0053] It can be understood that the number of battery cells 20 corresponding to each area can be one or multiple, for example, the heating wire 33 of one area corresponds to multiple battery cells 20 for heating.
[0054] Referring to Figure 4In some embodiments, the wiring density of the heating wires 33 in the third region 36 is greater than the wiring density of the heating wires 33 in the second region 35, so that the heating efficiency of the heating wires 33 in the third region 36 is greater than the heating efficiency of the heating wires 33 in the second region 35. Through the differential design of the heating efficiency of the heating wires 33 in the third region 36 and the heating efficiency of the heating wires 33 in the second region 35, after the multiple battery packs 3 are arranged in close proximity in the cabinet 2, the uniformity of the different battery cells 20 in the battery pack 3 after being heated by the heating film 30 can also be effectively guaranteed. For example, two adjacent battery packs 3 are stacked, the first direction X is consistent with the stacking direction, and the ends where the second regions 35 of the two adjacent battery packs 3 are located are close to each other, that is, the end where the second region 35 of one battery pack 3 is located is close to the end where the second region 35 of the other battery pack 3 is located. Since the two adjacent battery packs 3 are stacked, the heat dissipation effect at the position where the two battery packs 3 contact is poor, that is, the heat dissipation effect at the position where the second region 35 is located is poor. By making the heating efficiency of the second region 35 less than the heating efficiency of the third region 36, the second battery cell 22 corresponding to the second region 35 with low heat dissipation efficiency can be heated by the heating wires 33 in the second region 35, so as to avoid overheating. The third battery cell 23 corresponding to the third region 36 has a better heat dissipation effect, so that the third battery cell 23 can be heated by the heating wires 33 in the third region 36 with higher heating efficiency, so as to guarantee that the third battery cell 23 can be heated to a preset temperature range. In summary, the uniformity of the multiple battery cells 20 in the battery pack 3 can be effectively guaranteed, and the service life and safety of the battery pack 3 can be improved.
[0055] For example, in some embodiments, as shown in FIG. 6, the heating film 30 is arranged on the outer surface of the battery pack 3, and the heating film 30 is arranged on the outer surface of the battery pack 3 in the form of a ring. The heating film 30 arranged in the form of a ring can effectively heat the battery cells 20 in the battery pack 3, and the heating film 30 arranged in the form of a ring can also effectively guarantee the uniformity of the battery cells 20 in the battery pack 3. Figure 6As shown in the schematic view of one arrangement of the plurality of battery packs 3, at least two clusters of battery packs 3 are arranged in the cabinet 2 along the first direction X, and the second regions 35 of the two clusters of battery packs 3 are arranged close to each other at one end in the first direction X, that is, the two battery packs 3 are arranged along the first direction X, and among the two heating films 30 of the two battery packs 3, the two second regions 35 are located between the two third regions 36 in the first direction X. Since the heating efficiency of the second region 35 is low, the spacing between the two clusters of battery packs 3 can be reduced, the space utilization of the battery pack 3 in the cabinet 2 is improved, and the energy density of the energy storage device 1 is improved. Moreover, the heat dissipation efficiency at the position where the two clusters of battery packs 3 are close to each other is reduced, and since the heating efficiency of the second region 35 is lower than that of the third region 36, the second electric core 22 corresponding to the second region 35 can be heated by the heating wire 33 of the second region 35, so as to avoid the situation of over-heating. The third electric core 23 corresponding to the third region 36 has better heat dissipation effect, so that the third electric core 23 can be heated to the preset temperature range by the heating wire 33 of the third region 36 with higher heating efficiency. In summary, the temperature uniformity of the plurality of electric cores 20 in the battery pack 3 can be effectively guaranteed, and the service life and safety of the battery pack 3 are improved.
[0056] Referring to Figure 4 and Figure 6 In some embodiments, the first region 34 includes a fourth region 37 and a fifth region 38 arranged along the first direction X, the fourth region 37 is located on the side of the fifth region 38 close to the second region 35, that is, the fourth region 37 is close to the second region 35, and the fifth region 38 is close to the third region 36. Since the second regions 35 of the two adjacent battery packs 3 are arranged close to each other at one end in the first direction X, the heat dissipation effect of the end corresponding to the second region 35 is poor, so the heat dissipation effect of the electric core 20 corresponding to the fourth region 37 adjacent to the second region 35 is lower than that of the electric core 20 corresponding to the fifth region 38 adjacent to the third region 36. In order to guarantee the temperature uniformity of the electric core 20 corresponding to the fourth region 37 and the electric core 20 corresponding to the fifth region 38 after being heated, the wiring density of the heating wire 33 of the fifth region 38 is greater than that of the heating wire 33 of the fourth region 37, so that the electric core 20 corresponding to the fourth region 37 and the electric core 20 corresponding to the fifth region 38 can be heated differently, so that the temperature difference between the electric core 20 corresponding to the fourth region 37 and the electric core 20 corresponding to the fifth region 38 after being heated is controlled within a threshold value, so as to improve the temperature uniformity of the plurality of electric cores 20, and improve the service life and safety performance of the battery pack 3.
[0057] It can be understood that in other embodiments, the heating film 30 can also be divided into more regions, and the number of regions included in the heating film 30 is more, so that the plurality of battery cells 20 can be uniformly heated to ensure the uniformity of the plurality of battery cells 20, with reference to the number of the plurality of battery cells 20 arranged along the first direction X.
[0058] With reference to Figure 4 In some embodiments, the layout of the heating wire of the heating film 30 is facilitated, the heating wire 33 of the first region 34, the heating wire 33 of the second region 35 and the heating wire 33 of the third region 36 are connected in series, so that the heating wire 33 of the first region 34, the heating wire 33 of the second region 35 and the heating wire 33 of the third region 36 flow through the same current, so as to effectively and accurately control the heating power of each region, and improve the uniformity of the plurality of battery cells 20 after heating.
[0059] For example, in some embodiments, the heating wire 33 of the first region 34, the heating wire 33 of the second region 35 and the heating wire 33 of the third region 36 are formed by the same resistance wire.
[0060] It can be understood that in other embodiments, the heating wire 33 of the first region 34, the heating wire 33 of the second region 35 and the heating wire 33 of the third region 36 are connected in parallel, so as to independently control the heating wire 33 of the first region 34, the heating wire 33 of the second region 35 and the heating wire 33 of the third region 36, and reasonably heat different battery cells 20 according to needs. For example, in some embodiments, the heating wire 33 of the second region 35, the heating wire 33 of the fourth region 37, the heating wire 33 of the fifth region 38 and the heating wire 33 of the third region 36 are connected in parallel.
[0061] With reference to Figure 4 In some embodiments, the heating wire 33 of the first region 34 is arranged at intervals in the second direction Y, the heating wire 33 of the second region 35 is arranged at intervals in the second direction Y, the heating wire 33 of the third region 36 is arranged at intervals in the second direction Y, and the second direction Y is perpendicular to the first direction X. The wiring density of the heating wire 33 of each region can be calculated by the number of the heating wire 33 of each region in the second direction Y, and the more the number of the heating wire 33 in the second direction Y, the greater the wiring density of the heating wire 33 of the region.
[0062] In some embodiments, the heating wires 33 in the first region 34 are evenly spaced in the second direction Y, the heating wires 33 in the second region 35 are evenly spaced in the second direction Y, and the heating wires 33 in the third region 36 are evenly spaced in the second direction Y to improve the temperature uniformity of heating the battery cell 20. It is understood that in other embodiments, the heating wires 33 in the first region 34 may not be evenly spaced in the second direction Y, the heating wires 33 in the second region 35 may not be evenly spaced in the second direction Y, and the heating wires 33 in the third region 36 may not be evenly spaced in the second direction Y.
[0063] Reference Figure 2 and Figure 3 In some embodiments, the heating film 30 is disposed between the side plate 12 of the housing 10 and the multiple battery cells 20. By disposing of the heating film 30 between the side plate 12 of the housing 10 and the multiple battery cells 20, the heating film 30 can not only heat the battery cells 20, but also the heat-conducting layer 31 of the heating film 30 is insulating, so the heating film 30 can also be used to insulate and isolate the multiple battery cells 20 and the side plate 12. Thus, the heating film 30 can serve two purposes, increasing the functions of the battery pack 3 without complicating the structure of the battery pack 3.
[0064] It is understood that in some other embodiments, the heating film 30 may also be disposed between the bottom plate 13 of the housing 10 and the battery cell 20. Or the heating film 30 may be disposed between two battery modules, etc. It is also possible that the heating film 30 is provided in multiple of the above locations.
[0065] Figure 7 This is a schematic diagram illustrating the wiring arrangement of the heating wire 33 in another heating film 30 provided in this embodiment. This embodiment is compared to... Figure 4 The new wiring method formed by the change of wiring method in the embodiment, the structure of heating film 30 and the way it cooperates with battery cell 20 can all refer to the previous embodiment, and will not be repeated here.
[0066] Reference Figure 7In some embodiments, the wire density of the heating wire 33 of the heating film 30 gradually increases from the middle part of the heating film 30 to any one end of the heating film 30 in the first direction X. Since the middle part of the plurality of battery cells 20 in the first direction X has the worst heat dissipation effect, the two ends are the best, and the heat dissipation effect shows a gradually changing trend, in the present embodiment, the wire density of the heating wire 33 of the heating film 30 gradually increases from the middle part of the heating film 30 to any one end of the heating film 30 in the first direction X. The temperature of the plurality of battery cells 20 can be more accurately controlled, so that the temperature uniformity of the plurality of battery cells 20 is better, such as controlling the temperature difference of the plurality of battery cells 20 within a smaller threshold, such as 3°C. To improve the consistency of the temperature of the plurality of battery cells 20 of the battery pack 3, and thus improve the service life of the battery pack 3.
[0067] The above merely illustrates the specific embodiments of the present application, but the protection scope of the present application is not limited thereto, any person skilled in the art can easily think of the changes or replacements within the technical range disclosed by the present application, which should be covered within the protection scope of the present application. Therefore, the protection scope of the present application should be subject to the protection scope of the claims.
Claims
1. A battery pack, characterized by, The battery pack comprises a shell, a plurality of battery cells arranged along a first direction in the shell, and a heating film attached to the plurality of battery cells, the heating film extending to both ends of the plurality of battery cells in the first direction, In the first direction, the wiring density of the heating wires in the middle part of the heating film is less than the wiring density of the heating wires at both ends of the heating film.
2. The battery pack of claim 1, wherein, The heating film comprises a plurality of regions arranged along the first direction, the plurality of regions comprising a first region corresponding to the middle part of the heating film, and a second region and a third region located on both sides of the first region, the second region and the third region corresponding to both ends of the heating film, the wiring density of the heating wires in the first region being less than the wiring density of the heating wires in the second region and the wiring density of the heating wires in the third region respectively, and the wiring density of the heating wires in the second region being less than the wiring density of the heating wires in the third region.
3. The battery pack of claim 2, wherein, A first battery cell in the plurality of battery cells is arranged in the first region, a second battery cell in the plurality of battery cells is arranged in the second region, and a third battery cell in the plurality of battery cells is arranged in the third region, the first battery cell being located between the second battery cell and the third battery cell in the first direction.
4. The battery pack of claim 2 or 3, wherein, The first region comprises a fourth region and a fifth region arranged along the first direction, the fourth region being located on the side of the fifth region close to the second region, and the wiring density of the heating wires in the fifth region being greater than the wiring density of the heating wires in the fourth region.
5. The battery pack of any one of claims 2-4, wherein, The heating wires in the first region, the heating wires in the second region, and the heating wires in the third region are connected in series.
6. The battery pack of any one of claims 2-4, wherein, The heating wires in the first region, the heating wires in the second region, and the heating wires in the third region are connected in parallel.
7. The battery pack of any one of claims 2-6, wherein, The heating wires in the first region, the heating wires in the second region, and the heating wires in the third region are uniformly spaced in a second direction perpendicular to the first direction.
8. The battery pack of any one of claims 1-6, wherein, In the first direction, from the middle part of the heating film to any one end of the heating film, the wiring density of the heating wires in the heating film gradually increases.
9. The battery pack of any one of claims 1-8, wherein, The heating film is arranged between the side plate of the shell and the plurality of battery cells, or the heating film is arranged between the bottom plate of the shell and the plurality of battery cells.
10. The battery pack of any one of claims 1-9, wherein, The battery pack further comprises a heat insulation film arranged between the heating film and the shell.
11. An energy storage device, characterized by, The energy storage device comprises a cabinet body and a plurality of battery packs as claimed in any one of claims 1-10, the plurality of battery packs being arranged in the cabinet body.
12. The energy storage device of claim 11, wherein, The regions corresponding to both ends of the heating film in the first direction are the second region and the third region respectively, the wiring density of the heating wires in the second region is less than the wiring density of the heating wires in the third region, adjacent two battery packs are arranged along the first direction, and among two heating films in the adjacent two battery packs, the two second regions are located between the two third regions in the first direction.