A single battery, a battery module, and a battery pack

Abstract

The application discloses a single battery, a battery module and a battery pack, wherein the single battery comprises two first surfaces oppositely arranged along a first direction, a plurality of side surfaces and a first temperature and pressure patch. The plurality of side surfaces correspond to the edges of the first surfaces one by one and are connected between the two first surfaces. The first temperature and pressure patch is fixed on at least one first surface and covers at least the structural center of the first surface to detect the temperature and expansion force of the single battery. In the application, the first temperature and pressure patch is arranged at the structural center of the first surface of the battery cell, and the heat and stress are relatively concentrated in the area. Arranging the first temperature and pressure patch in the area can synchronously perceive the real temperature and expansion force of the battery cell, reduce signal attenuation and lag caused by the heat conduction and force transmission path, and thus improve the detection accuracy of the temperature and expansion force of the single battery.

Description

Technical Field

[0001] This application relates to the field of battery technology, and in particular to a single cell, a battery module, and a battery pack. Background Technology

[0002] With the widespread application of batteries in new energy vehicles, energy storage power stations and other fields, the safety and reliability of battery modules have become a key focus of the industry.

[0003] During battery charging and discharging, the battery cell generates heat and releases gas. Uneven temperature distribution or abnormal internal pressure can affect cell consistency, cycle life, and even trigger thermal runaway. Current battery module temperature detection typically relies on sensors such as thermistors and thermocouples attached to the module casing or top cover. The collected data deviates from the actual internal temperature of the cell, making it difficult to accurately reflect the thermal state of a single cell and thus affecting the accuracy of discharge power control and thermal management. Furthermore, the detection of cell bulging largely depends on changes in module-level gaps or indirect measurements using external strain gauges. This only reflects overall structural changes, and the measurement results are easily affected by assembly tolerances and casing stiffness, making it difficult to accurately assess the cell's health status and failure trends. Utility Model Content

[0004] This application provides a single battery cell, a battery module, and a battery pack, aiming to improve the accuracy of temperature detection and battery swelling status monitoring in existing battery modules.

[0005] To achieve the above objectives, according to a first aspect of this application, a single-cell battery is provided, comprising: Two first surfaces are set opposite each other along the first direction; Multiple sides, each corresponding to one of the edges of the first surface, are connected between the two first surfaces; A first temperature-pressure patch is fixed to at least one of the first surfaces, covering at least the structural center of the first surface, for detecting the temperature and expansion force of the single cell.

[0006] Optionally, the first thermo-pressure patch includes: The sampling unit includes a temperature sensing layer and a pressure sensing layer stacked together, wherein the temperature sensing layer is attached to the first surface; The lead-out portion is connected to the sampling portion and extends beyond the edge of the first surface.

[0007] Optionally, the sampling portion of the first thermo-pressure patch covers the structural center of the first surface; The plurality of sides includes a first side, and the single battery cell further includes: The negative terminal is located on the first side. The sampling portion of the second temperature-pressure patch is located on the first side and close to the negative electrode post.

[0008] Optionally, the sampling section of the first temperature-pressure patch and the sampling section of the second temperature-pressure patch are point sampling sections.

[0009] Optionally, the sampling section of the first temperature-pressure patch is a surface sampling section, and the sampling section of the second temperature-pressure patch is a point sampling section.

[0010] Optionally, the plurality of sides further includes a second side opposite to the first side; the single battery cell further includes: The third temperature-pressure patch has a sampling portion located at the center of the first region of the first surface, and the distance from the first region to the second side is less than the distance to the first side.

[0011] Optionally, the sampling section of the first temperature-pressure patch, the sampling section of the second temperature-pressure patch, and the sampling section of the third temperature-pressure patch are point sampling sections.

[0012] Optionally, the lead-out portion of the first temperature-pressure patch and the lead-out portion of the third temperature-pressure patch are led out from the same edge of the first surface.

[0013] According to a second aspect of this application, a battery module is provided, comprising a plurality of individual batteries as described in any one of the above claims, wherein a negative electrode post is provided on one side of each individual battery, and the first sides of the plurality of individual batteries are arranged opposite to each other, wherein the side of the individual battery with the negative electrode post is located on the same side of the battery module.

[0014] According to a third aspect of this application, a battery pack is also provided, including the battery module disclosed above.

[0015] Specifically, in this application, the first temperature-pressure patch is positioned at the structural center of the first side of the single-cell battery. During the charging and discharging process of the single-cell battery, the heat generated by the internal electrochemical reaction is conducted outward through the electrode layer, forming a heat accumulation area at the center of the large surface of the battery in the thickness direction (i.e., the first direction), which is the structural center region of the first side. This region is furthest from the surrounding heat dissipation boundaries, has the shortest heat flow path, and can fully reflect the actual heating status inside the single-cell battery. Therefore, placing the temperature-pressure patch at this position allows for direct sensing of the battery's true heating level, reducing temperature attenuation and response delay caused by intermediate heat-conducting media such as the casing, thermally conductive adhesive, and assembly tolerances, thereby significantly improving the sensitivity and accuracy of temperature detection. At the same time, the structural center region of the first side of the single-cell battery is subject to the least external constraints and is a free deformation zone, with the largest bulging displacement and the most concentrated stress distribution. When the temperature-pressure patch is placed in this region, its built-in pressure sensing unit can directly capture the most significant stress change signal on the battery surface, thereby accurately reflecting the battery's expansion state during charging and discharging, realizing real-time and quantitative monitoring of bulging behavior, and providing a reliable basis for battery safety assessment and failure early warning.

[0016] Other features and advantages of this application will be described in detail in the following detailed description section. Attached Figure Description To more clearly illustrate the technical solutions in the embodiments of this application, the accompanying drawings used in the description of the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of this application. For those skilled in the art, other drawings can be obtained based on these drawings without creative effort.

[0017] To gain a more complete understanding of this application and its beneficial effects, the following description will be provided in conjunction with the accompanying drawings, wherein the same reference numerals in the following description denote the same parts.

[0018] Figure 1 This is a schematic diagram of the structure of a single battery cell disclosed in an embodiment of this application. Figure 1 ; Figure 2 This is a schematic diagram of the structure of a single battery cell disclosed in an embodiment of this application. Figure 2 ; Figure 3 This is a schematic diagram of the structure of a single battery cell disclosed in an embodiment of this application. Figure 3 ; Figure 4 This is a schematic diagram of the structure of a single battery cell disclosed in an embodiment of this application. Figure 4 ; Figure 5 This is a schematic diagram of the structure of a single battery cell disclosed in an embodiment of this application. Figure 5 .

[0019] Explanation of reference numerals in the attached figures: 1. First page; 11. First area; 2. Side view; 21. First side view; 22. Second side view; 3. First temperature and pressure bonding; 4. Second temperature-pressure bonding; 5. Third temperature-pressure bonding; 6. Sampling section; 7. Lead-out section; 8. Negative terminal. Detailed Implementation

[0020] The technical solutions of the embodiments of this application will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only a part of the embodiments of this application, and not all of them. All other embodiments obtained by those skilled in the art based on the embodiments of this application without creative effort are within the protection scope of this application.

[0021] As described in the background section, during battery charging and discharging, electrochemical reactions occur inside the battery cell, generating heat, accompanied by electrolyte decomposition and gas evolution. If the heat cannot be dissipated in time, a temperature gradient will form inside the battery cell, resulting in uneven temperature distribution at different locations. This temperature difference not only affects the uniformity of the reaction rate of the active materials but also exacerbates local polarization, ultimately leading to capacity decay and a decrease in cycle life.

[0022] In some embodiments, temperature sensors are typically attached to the module housing or top cover to monitor battery temperature in real time. However, because the sensor is located far from the heat source of the battery cell, and there are multiple layers of thermally conductive media (such as the housing, insulating gaskets, thermally conductive adhesive, etc.) in between, heat conduction is subject to time delays and attenuation losses, resulting in a deviation between the measured surface temperature and the actual internal temperature of the battery cell. Furthermore, assembly tolerances between different battery cells and the module housing also cause differences in heat transfer paths, leading to poor consistency in measurement results and making it difficult to reflect the true thermal state of the battery cell. Meanwhile, in some embodiments, the detection of battery cell bulging often employs module-level gap change monitoring or external strain gauge detection. These methods cannot directly sense the deformation of a single battery cell surface and can only indirectly infer it through changes in the overall module structure. Due to the high rigidity of the module frame and the presence of initial gaps and elastic preload during assembly, minute battery cell expansion cannot be accurately detected. Simultaneously, changes in ambient temperature can cause thermal expansion and contraction of the housing, further interfering with the measurement results.

[0023] Therefore, in order to improve the accuracy of temperature detection in existing battery modules and the accuracy of cell swelling monitoring, this application discloses a single-cell battery.

[0024] Reference Figure 1Embodiment 1 of this application discloses a single-cell battery, which includes a first surface 1, a side surface 2, and a first temperature-pressure patch 3. The two first surfaces 1 are arranged opposite each other along a first direction. A plurality of side surfaces 2 correspond one-to-one with each edge of the first surface 1 and are connected between the two first surfaces 1. The first temperature-pressure patch 3 is fixed on at least one first surface 1, at least covering the structural center of the first surface 1, for detecting the temperature and expansion force of the single-cell battery.

[0025] In this embodiment, the first temperature-pressure patch 3 is disposed at the structural center of the first surface 1 of the single cell. During the charging and discharging process of the single cell, the heat generated by the internal electrochemical reaction is conducted outward through the electrode layer, forming a heat accumulation area at the center of the large surface (first surface) of the battery in the thickness direction (i.e., the first direction), which is the structural center region of the first surface 1. This region is farthest from the surrounding heat dissipation boundaries and has the shortest heat flow path, which can fully reflect the actual heating status inside the single cell. Therefore, by placing the temperature-pressure patch at this position, the true heating level of the battery can be directly sensed, reducing the temperature attenuation and response delay caused by intermediate heat-conducting media such as the casing, thermal conductive adhesive, and assembly tolerances, thereby significantly improving the sensitivity and accuracy of temperature detection. At the same time, the structural center region of the first surface 1 of the single cell is least constrained by external factors and belongs to the deformation free zone, where the bulging displacement is the largest and the stress distribution is the most concentrated. When the temperature-pressure patch is placed in this region, its built-in pressure sensing unit can directly capture the most significant stress change signal on the battery surface, thereby accurately reflecting the expansion state of the battery during the charging and discharging process, realizing real-time and quantitative monitoring of bulging behavior, and providing a reliable basis for battery safety assessment and failure early warning.

[0026] Specifically, in Embodiment 1 of this application, the first surface 1 is rectangular and has four edges, and the side surface 2 is provided with four edges.

[0027] Furthermore, in this embodiment, the temperature-pressure patch includes a sampling section 6 and a lead-out section 7. The sampling section 6 includes a temperature sensing layer and a pressure sensing layer stacked together. The sampling section 6 of the first temperature-pressure patch 3 covers the structural center of the first surface 1, and the temperature sensing layer is directly attached to the first surface 1, which can accurately reflect the actual temperature of the individual battery and avoid temperature decay and response delay caused by excessively long heat conduction paths. The pressure sensing layer is used to detect the expansion pressure generated by the battery during charging and discharging. The lead-out section 7 is connected to the sampling section 6 and extends beyond the edge of the first surface 1. When the individual battery is applied in a battery module, the first surfaces 1 of adjacent individual batteries are arranged opposite each other, and the lead-out section 7 extends beyond the edge of the first surface 1, which can transmit the electrical signals received by the temperature-pressure patch to an external circuit or battery management system.

[0028] In Embodiment 1 of this application, the sampling part 6 of the first temperature and pressure patch 3 is a point sampling part, and its sensing area corresponds to the structural center region of the first surface 1 of the single cell. Since the structural center of the first surface 1 of the single cell is the main area where heat and stress accumulate, point sampling can obtain representative temperature and mechanical data, achieving high-precision measurement while ensuring structural simplicity, thereby effectively improving the accuracy and response speed of temperature and pressure detection.

[0029] Reference Figure 2 Embodiment 2 of this application discloses a single-cell battery. Unlike Embodiment 1, the sampling part 6 of the first temperature and pressure patch 3 in Embodiment 2 is a surface sampling part. The surface sampling part can simultaneously monitor the temperature and expansion force changes at multiple points on the first surface 1 of the single-cell battery. By analyzing the signals at multiple points, local hot spots or stress concentration areas on the first surface 1 of the single-cell battery can be identified, enabling rapid identification of local overheating or local bulging of the single-cell battery and preventing the spread of thermal runaway.

[0030] Reference Figure 3 Embodiment 3 of this application discloses a single-cell battery, wherein the single-cell battery includes a first side 21 among its multiple sides 2. The single-cell battery also includes a negative electrode post 8, which is located on the first side 21. Unlike Embodiment 1, the single-cell battery disclosed in Embodiment 3 also includes a second temperature-pressure patch 4, the sampling portion 6 of which is located on the first side 21 where the negative electrode post 8 is located and close to the negative electrode post 8. The sampling portion 6 of the second temperature-pressure patch 4 is a point sampling portion.

[0031] Reference Figure 4 Embodiment 4 of this application discloses a single-cell battery, wherein the single-cell battery includes a first side 21 among its multiple sides 2. The single-cell battery also includes a negative electrode post 8, which is located on the first side 21. Unlike Embodiment 2, the single-cell battery disclosed in Embodiment 4 also includes a second temperature-pressure patch 4, the sampling portion 6 of which is located on the first side 21 where the negative electrode post 8 is located and close to the negative electrode post 8. The sampling portion 6 of the second temperature-pressure patch 4 is a point sampling portion.

[0032] In Examples 3 and 4, during the charging and discharging process of the battery, the negative terminal 8 serves as a current collection point, with a high current density in its region. Internal resistance heating along the conductive path and contact resistance at the electrode connection easily lead to localized temperature increases. Simultaneously, this region is also the connection point between the battery casing and the terminal encapsulation structure, resulting in complex mechanical constraints. During thermal expansion and gas evolution, it is prone to localized stress concentration or seal failure. By placing a second temperature-pressure patch 4 near the negative terminal 8, the temperature changes and stress state of the terminal region can be monitored in real time. Reference Figure 5Embodiment 5 of this application discloses a single-cell battery, wherein the multiple sides 2 of the single-cell battery include a second side 22. The second side 22 is disposed opposite to the first side 21. Unlike Embodiment 3, Embodiment 5 of this application also includes a third temperature-pressure patch 5. The sampling part 6 of the third temperature-pressure patch 5 is located at the center of the first region 11 of the first surface 1, and the distance from the first region 11 to the second side 22 is less than the distance to the first side 21. The sampling part 6 of the third temperature-pressure patch 5 is a point sampling part. The lead-out parts 7 of the first temperature-pressure patch 3 and the lead-out parts 7 of the third temperature-pressure patch 5 are led out from the same edge of the first surface 1.

[0033] In practical applications, during the charging and discharging process, the internal heat and gas generation of a battery exhibit non-uniformity along both the thickness and height directions. When a single cell is used in a battery module, the first side 21 of the single cell on the negative terminal post 8 is typically positioned opposite the top cover of the battery module, while the second side 22 of the single cell is typically positioned opposite the bottom of the battery module. The heat dissipation path is longer near the bottom of the battery module, resulting in a more pronounced gas accumulation effect. Therefore, by placing a third temperature and pressure patch 5 at the first region 11 of the single cell, multi-point monitoring of the vertical temperature gradient and bulging distribution of the battery can be achieved.

[0034] This application also discloses a battery module, which includes any of the above-mentioned single cells, each single cell having a negative electrode post 8 on one of its sides 2, and the first sides 1 of multiple single cells being arranged opposite to each other, with the side 2 of the single cell having the negative electrode post 8 located on the same side of the battery module.

[0035] In Embodiment Six, multiple individual battery cells are stacked tightly with their large surfaces (i.e., the first surface 1, the area of ​​the first surface 1 is larger than the area of ​​the side surface 2) facing each other, which makes the battery module more stable.

[0036] Embodiment 7 of this application also discloses a battery pack, which includes the battery module disclosed above.

[0037] In the description of this application, the terms "first" and "second" are used for descriptive purposes only and should not be construed as indicating or implying relative importance or implicitly specifying the number of technical features indicated. Therefore, a feature defined as "first" or "second" may explicitly or implicitly include one or more features. In the description of this application, "multiple" means two or more, unless otherwise explicitly specified.

[0038] In the above embodiments, the descriptions of each embodiment have different focuses. For parts not described in detail in a certain embodiment, please refer to the relevant descriptions in other embodiments.

[0039] The embodiments, implementation methods, and related technical features of this application can be combined and substituted for each other without conflict.

[0040] The above are merely preferred embodiments of this application and are not intended to limit this application in any way. Any simple modifications, equivalent changes, and alterations made to the above embodiments based on the technical essence of this application without departing from the scope of the technical solution of this application shall still fall within the scope of the technical solution of this application.

Claims

1. A single-cell battery, characterized in that, include: Two first surfaces (1) are arranged opposite each other along a first direction; Multiple side surfaces (2) correspond one-to-one with each edge of the first surface (1) and are connected between the two first surfaces (1); A first temperature-pressure patch (3) is fixed on at least one of the first surfaces (1) and covers at least the structural center of the first surface (1) for detecting the temperature and expansion force of the single cell.

2. The single-cell battery according to claim 1, characterized in that, The first temperature-pressure patch (3) includes: The sampling unit (6) includes a temperature sensing layer and a pressure sensing layer stacked together, wherein the temperature sensing layer is attached to the first surface (1); The lead-out part (7) is connected to the sampling part (6) and extends out of the edge of the first surface (1).

3. The single-cell battery according to claim 2, characterized in that, The sampling part (6) of the first temperature-pressure patch (3) covers the structural center of the first surface (1); The plurality of sides (2) includes a first side (21), and the single cell further includes: The negative terminal (8) is located on the first side (21); The second temperature-pressure patch (4) has a sampling part (6) located on the first side (21) and close to the negative electrode post (8).

4. The single-cell battery according to claim 3, characterized in that, The sampling section (6) of the first temperature-pressure patch (3) and the sampling section (6) of the second temperature-pressure patch (4) are point sampling sections.

5. The single-cell battery according to claim 3, characterized in that, The sampling part (6) of the first temperature-pressure patch (3) is a surface sampling part, and the sampling part (6) of the second temperature-pressure patch (4) is a point sampling part.

6. The single-cell battery according to claim 3, characterized in that, The plurality of sides (2) also include a second side (22) opposite to the first side (21); the single cell also includes: The third temperature-pressure patch (5) has a sampling part (6) located at the center of the first region (11) of the first surface (1), and the distance from the first region (11) to the second side surface (22) is less than the distance to the first side surface (21).

7. The single-cell battery according to claim 6, characterized in that, The sampling section (6) of the first temperature-pressure patch (3), the sampling section (6) of the second temperature-pressure patch (4), and the sampling section (6) of the third temperature-pressure patch (5) are point sampling sections.

8. The single-cell battery according to claim 7, characterized in that, The lead-out portion (7) of the first temperature-pressure patch (3) and the lead-out portion (7) of the third temperature-pressure patch (5) are led out from the same edge of the first surface (1).

9. A battery module, characterized in that, include: A plurality of individual batteries as described in any one of claims 1-8, wherein a negative electrode post (8) is provided on one side (2) of each individual battery, the first sides (1) of the plurality of individual batteries are arranged opposite to each other, and the side (2) of the individual battery with the negative electrode post (8) is located on the same side of the battery module.

10. A battery pack, characterized in that, Includes the battery module as described in claim 9.

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