Prismatic battery cell having a temperature sensor unit

Abstract

The present invention relates to a prismatic battery cell, comprising a housing containing an electrolyte, at least two electrode stacks which are arranged in the housing, and at least one temperature sensor unit, wherein each electrode stack comprises alternately stacked anode layers and cathode layers which each have separator layers arranged therebetween, wherein the anode layers are electrically connected to a first current collector and the cathode layers are electrically connected to a second current collector, wherein the first and second current collector each pass through a housing wall of the housing and can be electrically contacted from outside the housing, and wherein the temperature sensor unit comprises a sensor layer which is arranged between the two electrode stacks and a conductor connection point which passes through a housing wall of the housing, wherein the sensor layer has conductor tracks and at least one temperature sensor.

Description

[0001] CD 44592 December 16, 2025

[0002] Prismatic battery cell with temperature sensor unit

[0003] The present invention relates to a prismatic battery cell with

[0004] Temperature sensor unit.

[0005] Prismatic battery cells are well-known and are used particularly in applications with high demands on energy density and mechanical stability. Knowing the operating temperature of a prismatic battery cell is important, as temperature has a decisive influence on the cell's performance, safety, and lifespan. For example, in high-performance applications such as electromobility or stationary energy storage systems, precise cell temperature monitoring is essential to ensure reliable operation while simultaneously achieving maximum performance and lifespan. A uniform temperature distribution within the battery cell is important, for instance, to avoid thermal hotspots that can negatively affect the cell chemistry.Local overheating can lead to accelerated wear, loss of capacity, or in the worst case, thermal runaway, which jeopardizes the operational safety of the cell.

[0006] In a known manner, temperature sensors are either positioned outside the cell structure and the cell internal temperature is modeled via simulations, or inserted from above through the cell roof outside the electrode stacks and inside the battery cell housing, which also results in data with only low reliability and may disturb the electrochemical and thermal properties of the cell or make the measurement results insufficiently accurate.

[0007] It is therefore the object of the present invention to provide a prismatic battery cell that enables precise temperature measurement without significantly influencing the electrochemical, mechanical or thermal properties of the cell.

[0008] This problem is solved by the independent claims. Preferred embodiments of the invention are specified in the dependent claims, in the description, or in the figures, wherein further features described or shown in the dependent claims, in the description, or in the figures, individually or in any combination, can constitute subject matter of the invention unless the context clearly indicates otherwise.

[0009] The invention proposes a prismatic battery cell comprising a housing containing an electrolyte, at least two electrode stacks arranged in the housing and at least one temperature sensor unit,

[0010] wherein each electrode stack comprises alternately stacked anode layers and cathode layers with separator layers arranged between them, wherein the anode layers are electrically connected to a first current collector and the cathode layers to a second current collector, wherein the first and second current collectors each pass through a housing wall of the housing and are electrically contactable from outside the housing,

[0011] and wherein the temperature sensor unit comprises a sensor layer arranged between the two electrode stacks and a conductor connection passing through a housing wall of the housing, wherein the sensor layer has conductor tracks and at least one temperature sensor.

[0012] This makes it possible, in particular, to measure the temperature of a prismatic battery cell with exceptional accuracy. Specifically, the present invention enables the temperature of a prismatic cell to be measured with exceptional spatial resolution, while the cell structure is disturbed very little thermally, mechanically, and electrochemically by the specific arrangement of the sensor layer between the electrode stacks.

[0013] For the purposes of the present invention, the term "prismatic battery" refers in particular to a secondary battery, i.e., a rechargeable battery, characterized by a substantially prismatic basic shape. This substantially prismatic basic shape results in particular from the shape of the stacked layers of the battery. The stacked layers form two opposing, substantially parallel base surfaces, which, together with corresponding lateral surfaces, constitute the prismatic basic shape.

[0014] For the purposes of the present invention, a housing is understood to be, in particular, an outer casing that serves to spatially enclose the internal components of the battery and separate them from the environment. Housings of prismatic batteries typically consist of metals, such as aluminum or steel, and / or optionally plastics, such as polypropylene, polycarbonate, or polyamide.

[0015] For the purposes of the present invention, an electrode stack is understood to be, in particular, an arrangement of alternately stacked anode layers and cathode layers separated from one another by separator layers. Layers such as anode layer, cathode layer, or separator layer, for the purposes of the present invention, can be understood to mean that the corresponding objects are essentially two-dimensional, i.e., have a significantly smaller thickness in relation to the width and length of the object. Stacking layers, for the purposes of the present invention, is understood to mean, in particular, that the layers are arranged one on top of the other along their thickness.

[0016] The anode layer according to the present invention can be designed, in particular, for receiving lithium ions during the charging process of the prismatic battery cell. The cathode layer according to the present invention can be designed, in particular, for receiving electrons during the discharging process of the prismatic battery cell. According to the present invention, the separator layer is arranged between an anode layer and a cathode layer and allows, in particular, the flow of ions, such as lithium ions, while simultaneously preventing direct contact between the anode and cathode.

[0017] For the purposes of the present invention, an electrolyte is to be understood in particular as an ion-conducting substance, especially a liquid, which is arranged between anode layers and cathode layers and enables the transport of ions between the anode layers and the cathode layers.

[0018] Within an electrode stack, the anode layers are therefore separated from the cathode layers by a separator layer, with no contact between the anode and cathode layers and ion conductivity through the separator layer being enabled by means of the electrolyte.

[0019] In accordance with the present invention, a sensor layer of the temperature sensor unit is arranged between two electrode stacks. The outer layers of the electrode stacks are therefore separated from each other, particularly by the sensor layer, and are not in direct contact with each other. Thus, the electrode stacks are electrochemically separated from each other, so that no chemical reaction takes place between them.

[0020] This arrangement advantageously reduces electrochemical influences from the temperature sensor unit. Furthermore, by positioning the sensor layer between two electrode stacks, the mechanical stress on the sensor layer during battery charging can be kept as uniform as possible, since battery breathing or swelling is distributed across the sensor layer from both sides in a substantially even manner. This can potentially extend the sensor layer's lifespan. Additionally, this arrangement ensures that thermal influences on the battery are as uniform as possible. In particular, compared to a single-sided arrangement of such sensors, positioning them between two electrode stacks ensures that any thermal influence on the cell temperature from the temperature sensors occurs uniformly from within the battery cell.

[0021] Preferably, the layers may have a rectangular base shape. This advantageously allows the battery cell to essentially have the shape of a rectangular prism or cuboid, thus enabling particularly space-efficient use.

[0022] Preferably, the housing may have two essentially rectangular, parallel base surfaces and four lateral surfaces connecting the base surfaces. In other words, it may preferably be provided that the housing has essentially the shape of a rectangular prism. Accordingly, it may be provided that two lateral surfaces are arranged parallel to each other on opposite sides of the housing. Preferably, the rectangular prism may have a height that is less than the length and width of the two base surfaces.

[0023] Preferably, the prismatic battery cell may have exactly two electrode stacks.

[0024] Preferably, the sensor layer has a thickness in the range of > 50 pm to < 300 pm, preferably > 100 pm to < 200 pm. This advantageously ensures that the sensor layer is so thin that it only minimally affects the mechanical and electrochemical properties of the cell, while at the same time remaining sufficiently robust to withstand mechanical stresses within the cell.

[0025] Preferably, the sensor layer is a flexible PCB (Printed Circuit Board). This advantageously allows the sensor layer to be mechanically flexible and adapt to dynamic changes, such as swelling or mechanical stresses, within the cell without affecting its functionality or the integrity of the cell.

[0026] Preferably, the sensor layer is a four-day PCB, and it is particularly preferred that the conductive traces and temperature sensors are arranged on the outside of the PCB. This advantageously makes the arrangement of the electrical components more accessible and facilitates integration into the prismatic battery cell. Furthermore, it allows for even more precise temperature measurements.

[0027] Preferably, the sensor layer may comprise a first and a second substrate layer, with a conductor layer comprising the conductor tracks and the at least one temperature sensor being arranged at least partially between the substrate layers. This advantageously ensures that the conductor layer is securely embedded between the substrate layers, providing mechanical protection and simultaneously enabling precise positioning of the conductor tracks and temperature sensors within the sensor layer.

[0028] Preferably, the conductor tracks are arranged to contact the at least one temperature sensor and connect it to the conductor terminal. This advantageously ensures a reliable electrical connection between the temperature sensor and the conductor terminal, thereby guaranteeing interference-free signal transmission.

[0029] Preferably, the substrate layers may comprise polyimide and / or polyester, and preferably consist of at least one, and preferably both, of these materials. This advantageously results in the sensor layer exhibiting high thermal stability and chemical resistance to the electrolyte, while simultaneously maintaining mechanical flexibility.

[0030] Preferably, the temperature sensor is a platinum resistance thermometer. A platinum resistance thermometer is a temperature measurement sensor that utilizes the temperature dependence of electrical resistance. Platinum is used as a material because it exhibits a nearly linear relationship between temperature and resistance, possesses high stability, and displays excellent chemical resistance. The sensor typically consists of a thin wire or a thin layer of platinum, either deposited on a substrate or embedded in a protective casing. The resistance of the platinum is measured, and the corresponding temperature is determined via calibration. Preferably, the platinum resistance thermometer has a resistance value of 100 ohms at 0°C (PT100).This advantageously allows for high precision and stability in temperature measurement over a wide temperature range, ensuring the long-term reliability of the sensor even under demanding conditions.

[0031] Preferably, the sensor layer may have more than one temperature sensor, in particular a number greater than or equal to 2 to less than or equal to 1024 temperature sensors, preferably greater than or equal to 4 to less than or equal to 512, more preferably greater than or equal to 8 to less than or equal to 256, for example 16, 32, 64 or 128. This advantageously allows the temperature of the battery cell to be measured with particular accuracy at many points.

[0032] Preferably, the temperature sensors are arranged in a matrix. This means that the sensors are positioned uniformly in a defined grid. This advantageously creates a clear structure for positioning the sensors. As a result, the battery temperature can be measured with a particularly uniform distribution, and the temperature between different measuring points can be interpolated very effectively.

[0033] Preferably, the sensor layer may have > 0.1 temperature sensors per cm². 2 up to < 1 temperature sensor per cm 2 preferably has > 0.2 temperature sensors per cm², based on the area of ​​the sensor layer. 2 up to < 0.5 temperature sensors per cm 2This makes it advantageous to achieve temperature measurement with high spatial resolution.

[0034] Preferably, the conductor connection is routed through a sealed gap in the housing wall, preferably with a sealing material. This advantageously ensures that the prismatic battery cell remains sealed and prevents electrolyte leakage.

[0035] In a preferred embodiment, the housing can be a substantially rectangular prism, with the conductor connection passing through a lateral surface of the housing. This allows the conductor connection to be routed out of the electrode stacks particularly easily, and an evaluation unit to be connected with particular ease.

[0036] Preferably, the electrode stacks are arranged identically in their sequence and number of layers, or mirrored along the sensor layer. This advantageously allows the sensor layer to be positioned centrally within the battery cell.

[0037] In a preferred embodiment, the housing may be a substantially rectangular prism, and the first and second current collectors may each pass through a surface of the housing. In a particularly preferred embodiment, the first and second current collectors may each pass through the same surface of the housing or through opposing, parallel surfaces. This allows the current collectors to be connected to the anode layers particularly easily.

[0038] Cathode layers are electrically connected, making it particularly easy to contact the battery cell from the outside.

[0039] In a particularly preferred embodiment, the first and second current collectors can each be routed through a different surface than the conductor connection, wherein, in particular, the first and second current collectors are each routed through the same surface of the housing or through opposing, parallel surfaces, and the conductor connection is routed through a surface perpendicular to these. This makes it particularly easy to connect the conductor connections.

[0040] In a first preferred alternative embodiment, the at least two electrode stacks may use a common current collector for the anode layers and a common current collector for the cathode layers. This advantageously simplifies the electrical conduction and allows for a more compact cell structure.

[0041] In a second preferred alternative embodiment, the at least two electrode stacks can each have a current collector for the anode layers and cathode layers. This advantageously allows the electrode stacks to be controlled individually.

[0042] Preferably, each electrode stack has > 10 to < 500 anode layers or cathode layers, preferably > 20 to < 250, more preferably > 50 to < 100. This advantageously allows the prismatic battery cell to have a high energy density and the temperature to be measured with particularly good accuracy.

[0043] Preferably, the anode and cathode layers in the electrode stacks are stacked alternately and with uniform thickness, the thickness of the individual layers being in the range of 10 to 200 pm. This advantageously achieves a uniform current distribution and optimized electrochemical behavior.

[0044] Preferably, the outer layers of the electrode stacks are insulated from adjacent components of the battery cell by separator layers or the sensor layer. This advantageously provides electrical and mechanical protection for the electrode stacks.

[0045] The invention further proposes a temperature sensor unit for a prismatic battery cell according to the invention, comprising a sensor layer that can be arranged between two electrode stacks and a conductor connection that can be passed through a housing wall of the housing, wherein the sensor layer has conductor tracks and at least one temperature sensor.

[0046] The temperature sensor unit advantageously enables precise and spatially resolved temperature measurement within the prismatic battery cell, while the mechanical, thermal, and electrochemical integrity of the cell is not significantly affected by the special arrangement and design of the sensor layer. The conductor connection, which can be routed through the housing wall, allows for reliable and interference-free signal transmission from the temperature sensors to the outside. The conductor tracks and temperature sensors within the sensor layer are optimally protected and mechanically stable, thus ensuring reliable long-term functionality when used in the battery cell.

[0047] Furthermore, the invention proposes the use of a temperature sensor unit according to the invention for temperature measurement in a prismatic battery cell according to the invention.

[0048] By using the temperature sensor unit according to the invention for temperature measurement in a prismatic battery cell, it is advantageously possible to precisely detect thermal hotspots or temperature gradients within the cell, which can enable better control of the thermal conditions. This contributes to optimizing battery operation, extending service life, and increasing operational reliability.

[0049] The invention also proposes an electrical system comprising a prismatic battery cell according to the invention and an electrical consumer electrically connected to the prismatic battery cell.

[0050] This allows the prismatic battery cell to be efficiently integrated into a wide variety of applications, reliably supplying energy to the electrical device. The combination with the prismatic battery cell enables high energy density and precise monitoring of cell conditions.

[0051] Preferably, the electrical system includes an evaluation unit connected to the conductor terminal of the temperature sensor unit. This advantageously enables the continuous acquisition and evaluation of the temperature data from the prismatic battery cell to ensure accurate monitoring of the operating conditions. This supports optimized control of the electrical system and increases its efficiency and operational reliability.

[0052] Further advantages and advantageous embodiments of the method according to the invention are illustrated by the figures and explained in the following description. It should be noted that the figures are for descriptive purposes only and are not intended to limit the invention in any way.

[0053] They show

[0054] Fig. 1 schematically shows an electrode stack in cross-section, as it can be used in a prismatic battery cell according to the invention.

[0055] Fig. 2 schematically shows a prismatic battery cell according to the invention in a preferred embodiment in a cross-section through the electrode stacks, and Fig. 2 schematically shows a top view of a cross-section of the prismatic battery cell according to the preferred embodiment from Fig. 1 parallel to the sensor layer.

[0056] Fig. 1 schematically shows a cross-sectional view of an electrode stack 14 as it can be used in the prismatic battery cell 1 according to the invention. The electrode stack 14 comprises an arrangement of alternately stacked anode layers 16 and cathode layers 18, each separated from the other by separator layers 20. Each anode layer 16 is electrically connected to a first current collector 22, while each cathode layer 18 is electrically connected to a second current collector 24. The electrolyte 12 enables the flow of ions through the separator layers 20 between the anode layers 16 and cathode layers 18.

[0057] Fig. 2 schematically shows a prismatic battery cell 1 according to the invention, in a preferred embodiment, in a cross-section through the electrode stacks 14. The housing 10 with its outer surfaces is visible, of which two opposing outer surfaces 11a are shown, through which the first current collector 22 and the second current collector 24 pass. Two electrode stacks 14 are arranged inside the housing 10, configured, for example, as shown in Fig. 1. The sensor layer 28 is located between the electrode stacks 14. The electrolyte 12 surrounds the layers.

[0058] Fig. 3 schematically shows a top view of a cross-section of the prismatic battery cell 1 according to the preferred embodiment from Fig. 1, parallel to the sensor layer 28. The temperature sensors 32 are arranged in the sensor layer 28, and the conductor tracks 30, which are shown only schematically in a simplified manner, connect the temperature sensors 32 to the conductor terminal 34. The first current collector 22 and the second current collector 24 are again visible and are guided through the opposing cladding surfaces 11a. The second current collector is guided through a cladding surface 11b of the housing 10, which is perpendicular to the two opposing cladding surfaces 11a.

[0059] Reference symbol:

[0060] 1: prismatic battery cell

[0061] 10: Housing

[0062] 11a: opposite lateral surfaces

[0063] 11b: vertically oriented lateral surface

[0064] 12: Electrolyte

[0065] 14: Electrode stack

[0066] 16: Anode layer

[0067] 18: Cathode layer

[0068] 20: Separator layer

[0069] 22: Current collector (first)

[0070] 24: Current collector (second)

[0071] 26: Temperature sensor unit

[0072] 28: Sensor layer

[0073] 30: Conductor tracks

[0074] 32: Temperature sensor

[0075] 34: Conductor connection

[0076] 36: Evaluation unit

[0077] 38: Consumers

Claims

Patent claims 1. Prismatic battery cell (1) comprising a housing (10) containing an electrolyte (12), at least two electrode stacks (14) arranged in the housing (10) and at least one temperature sensor unit (26), wherein each electrode stack (14) comprises alternately stacked anode layers (16) and cathode layers (18) with separator layers (20) arranged between them, wherein the anode layers (16) are electrically connected to a first current collector (22) and the cathode layers (18) are electrically connected to a second current collector (24), wherein the first and second current collectors (22, 24) are each passed through a housing wall of the housing (10) and are electrically contactable from outside the housing (10), and wherein the temperature sensor unit (26) comprises a sensor layer (28) arranged between the two electrode stacks (14) and a conductor connection (34) passing through a housing wall of the housing (10), wherein the sensor layer (28) has conductor tracks (30) and at least one temperature sensor (32).

2. Prismatic battery cell (1) according to the preceding claim, wherein the sensor layer (28) has a thickness in the range of > 50 pm to < 300 pm, preferably > 100 pm to < 200 pm.

3. Prismatic battery cell (1) according to any one of the preceding claims, wherein the sensor layer (28) has a thickness in the range of > 50 pm to < 300 pm, preferably > 100 pm to < 200 pm.

4. Prismatic battery cell (1) according to one of the preceding claims, wherein the sensor layer (28) has a first and a second substrate layer, wherein a conductor layer is arranged at least partially between the substrate layers, comprising the conductor tracks (30) and the at least one temperature sensor (32).

5. Prismatic battery cell (1) according to the preceding claim, wherein the substrate layers comprise polyimide and / or polyester, in particular consisting thereof, wherein preferably at least one, in particular both substrate layers consist of polyimide.

6. Prismatic battery cell (1) according to one of the preceding claims, wherein the temperature sensor (32) is a platinum resistance thermometer.

7. Prismatic battery cell (1) according to one of the preceding claims, wherein the sensor layer (28) has more than one temperature sensor (32), in particular a number greater than or equal to 2 to less than or equal to 1024 temperature sensors (32), preferably greater than or equal to 4 to less than or equal to 512, more preferably greater than or equal to 8 to less than or equal to 256, for example 16, 32, 64 or 128.

8. Prismatic battery cell (1) according to one of the preceding claims, wherein the conductor connection (34) is passed through a sealed gap in the housing wall of the housing (10), preferably the gap being sealed with a sealing material.

9. Prismatic battery cell (1) according to one of the preceding claims, wherein the housing (10) is a substantially rectangular prism and the conductor connection (34) is passed through a lateral surface of the housing (10).

10. Prismatic battery cell (1) according to the previous claim, wherein the first and second current collectors (22, 24) are each passed through a different lateral surface than the conductor terminal (34), wherein in particular the first and second current collectors (22, 24) are each passed through the same lateral surface of the housing (10) or through opposing parallel lateral surfaces (11a) and the conductor terminal (34) is passed through a lateral surface (11b) perpendicular to it.

11. Prismatic battery cell (1) according to one of the preceding claims, wherein each electrode stack (14) has > 10 to < 500 anode layers (16) or cathode layers (18), preferably > 20 to < 250, more preferably > 50 to < 100.

12. Temperature sensor unit (26) for a prismatic battery cell (1) according to one of the preceding claims, comprising a sensor layer (28) that can be arranged between two electrode stacks (14) and a conductor connection (34) that can be passed through a housing wall of the housing (10), wherein the sensor layer (28) has conductor tracks (30) and at least one temperature sensor (32).

13. Use of a temperature sensor unit (26) according to claim 12 for temperature measurement in a prismatic battery cell.

14. Electrical system comprising a prismatic battery cell (1) according to one of the preceding claims and an electrical consumer (38) electrically connected to the prismatic battery cell (1).

15. Electrical system according to claim 14, comprising an evaluation unit (36) connected to the conductor connection (34) of the temperature sensor unit (26).

Images