Vent integration for battery cells

Abstract

Housing element (101) for a battery cell (100), said housing element being manufactured in one piece, having equal wall thickness on four sides and comprising: a vent element (103) which is fixed to a vent opening in the housing element, wherein the vent element (103) comprises a positioning device (104) which ensures positioning in a defined installation position.

Description

[0001] Description

[0002] Vent integration for battery cells

[0003] The technical field of the described invention relates to the design and manufacture of battery cells, in particular the integration of burst membranes (vents) into the housing of battery cells.

[0004] Vents act as a safety mechanism in battery cells, opening in a controlled manner in the event of overpressure within the cell, for example, due to overheating or mechanical damage. This relieves the pressure and prevents a potentially dangerous cell rupture or explosion. Without vents, a sudden pressure increase could lead to catastrophic failures, endangering not only the battery but also the entire device.

[0005] Vents are manufactured using a precise process, often involving the use of metal foils or special plastics. The vents are either embossed or the material and its thickness are selected so that the vent yields or bursts under a specific pressure. The vents are typically installed during battery cell assembly, where they are integrated into the battery casings.

[0006] The object of the present invention is to provide an improved housing element with a vent element.

[0007] This problem is solved by the housing element according to claim 1. This problem is further solved by the battery cell according to claim 9 and the vehicle according to claim 10.

[0008] Further advantageous embodiments of the invention will become apparent from the dependent claims and the following description of preferred embodiments of the present invention.

[0009] A housing element according to the invention for a battery cell, which is manufactured in one piece and has the same wall thickness on four sides, comprises a vent element which is fixed to a vent opening in the housing element, wherein the vent element comprises a positioning device which ensures positioning in a defined installation position.

[0010] The casing element is a structural component that serves as an outer shell or container for various components. In the context of battery cell construction, the casing element can be made of materials such as metals (or plastics) that are both lightweight and robust. It protects the internal components of the battery cell from mechanical damage, environmental influences, and chemical reactions. The casing element is often manufactured as a single piece to increase structural integrity and reduce manufacturing costs. It may include special openings or devices, such as vents, that serve as safety mechanisms.

[0011] A housing element can be a single component or a specific part of a housing that contributes to the overall design and functionality of the housing. The housing can be the complete outer shell or container that encloses and protects the battery cell. While the housing as a whole fulfills several functions, such as protecting the internal components, providing structural support, and ensuring safety, a housing element focuses on a specific task within this shell. For example, a housing element might be a wall or a cover (lid). The housing element includes a special opening, the vent opening, to which the vent is attached. This opening is sealed by the vent as long as the vent remains intact. Thus, the housing is the overall structure composed of several housing elements.

[0012] One-piece can mean that a part or component is made from a single piece of material, without being assembled or joined from multiple parts.

[0013] A battery cell is the smallest functional unit of a battery, converting chemical energy into electrical energy. It consists of an anode, a cathode, an electrolyte, and a separator, all enclosed in a casing. The anode and cathode are the electrodes between which the chemical reaction takes place, generating electrical energy. The electrolyte allows the flow of ions between the electrodes, while the separator prevents the electrodes from coming into direct contact and causing a short circuit. Battery cells can be used individually or combined in series and parallel circuits to achieve the desired voltage and capacity for various applications, such as electric vehicles, portable electronic devices, and energy storage systems.

[0014] Uniform wall thickness can refer to the consistent thickness of the walls of a housing element across all sides. In battery cell design, this means that the housing walls have the same material thickness throughout. If no step is required at the opening of the housing element for integrating the vent, the wall thickness does not need to be increased there, and the energy-storing components of the battery cell occupy a larger proportion of the volume, thus increasing the energy density.

[0015] The housing element can, for example, consist of four sides that can be closed off by two covers. The housing element can have the same wall thickness on all four sides.

[0016] A vent element can be a safety component integrated into battery cells and other systems to allow controlled pressure release in the event of overpressure. It can be made of metal, plastic, or a combination of both, and includes a rupture diaphragm that is designed to rupture or break at a specific pressure.

[0017] The positioning device can be a mechanical device or a structural feature used to precisely hold a component in a defined installation position and then fix it in that position. The positioning device can ensure that the valve element is placed at the intended location within the housing element—at the valve opening—to guarantee optimal functionality and safety. This can be achieved, for example, by mechanical steps, guides, notches, positioning pins, or other features that hold the component in the desired position.

[0018] In the defined installation position, the vent element covers the vent opening and can be fixed there, so that the vent opening is sealed by the fixed vent element.

[0019] The battery cell can be a prismatic battery cell. A prismatic battery cell is a type of battery cell characterized by its rectangular, cuboid geometry. This shape offers several advantages over cylindrical or other cell shapes, particularly in terms of space utilization and packing density.

[0020] Prismatic cells allow for more efficient use of available volume in battery packs because they can be packed tightly together without gaps. This results in higher energy density and better heat dissipation, improving battery performance and lifespan. Their flat, rectangular shape also facilitates integration into various applications, from electric vehicles to stationary energy storage systems.

[0021] There are versions where the housing element is made of aluminum.

[0022] Aluminum offers several advantages: It is lightweight and robust, which reduces the overall weight of the battery cell and increases energy efficiency. Its excellent thermal conductivity improves the cell's thermal stability and safety. Furthermore, aluminum is corrosion-resistant, which increases the battery cell's lifespan. It is also easy to process, which can lower manufacturing costs and simplify production processes.

[0023] There are versions where the housing element is the cell cup.

[0024] The cell cup can be sealed with two lids and can enclose the anode, cathode, electrolyte, and separator. This protects them from external influences such as moisture and mechanical damage. The cell cup can be manufactured using a primary forming process, particularly extrusion.

[0025] Forming and forming processes are fundamental manufacturing techniques in material processing and manufacturing. Forming processes refer to processes in which a workpiece is created from a shapeless material by shaping it into a solid form. Examples include casting, sintering, and 3D printing, in which liquid, powdered, or pasty raw materials are placed in a mold and solidified. Forming processes, on the other hand, involve changing the shape of an existing solid workpiece through plastic deformation without removing or adding material. Typical forming processes include forging, rolling, bending, and deep drawing.

[0026] Extrusion, also known as ductile forming, is a forming process in which a material, usually metal or plastic, is forced through a die to create continuous profiles with a constant cross-section. The starting material, often in the form of a cylindrical block or blank, is fed into a heated chamber and forced through the die under high pressure. The resulting product can have a variety of cross-sectional shapes, such as bars, tubes, rails, or complex profiles. Extrusion offers the advantage of producing long, uniform parts with high precision and good surface quality and is frequently used in the construction, automotive, and aerospace industries. Because the material flows under pressure during extrusion and is therefore temporarily shapeless, extrusion can also be considered a primary forming process.

[0027] There are designs where the positioning device is a circumferential centering stage that centers the vent element at the vent opening.

[0028] A circumferential feature can describe a property or characteristic that extends continuously and uninterrupted around the entire circumference of an object. In design and manufacturing, this means that a specific element, such as an edge, groove, or step, runs in a continuous circle or rectangle around a component. This property ensures a uniform distribution and can contribute to the component's stability and functionality. A circumferential feature can, for example, serve to guarantee even pressure distribution or to enable a secure and tight connection between two components.

[0029] A centering step can be a raised or recessed structure designed to precisely hold or center a component in a specific position. In technical applications, a centering step is often used to ensure that another component, such as a cover, gasket, or vent, is positioned exactly where it should be. This is particularly important for ensuring proper function and sealing. The centering step can act as a guide or stop, fixing the component in the desired position and thus enabling precise assembly or fixing.

[0030] There are versions in which the vent element is fixed to the vent opening by means of a material bond.

[0031] A material-bonded connection is a type of joining technique in which the joined parts are held together by molecular or atomic forces. This is typically achieved through processes such as welding, soldering, gluing, or sintering. A material-bonded connection creates a strong and permanent bond because the materials fuse together or form a chemical bond at the joint. This type of connection is characterized by high strength and tightness, as no mechanical fasteners such as screws or rivets are required. Material-bonded connections are particularly advantageous in applications where high strength and reliability are required, such as in the construction of battery cells to create a tight seal between the casing and the valve.

[0032] There are versions where the vent element is fixed to the vent opening by means of welding.

[0033] Welding is a widely used process for joining materials, especially metals, using a metallurgical bond. In this process, the workpieces to be joined are melted at their contact surfaces by the application of heat, thus fusing them together. This heat can be generated by various methods, such as arc welding, gas welding, laser welding, or friction welding. Welding creates a strong and permanent bond that often achieves or even surpasses the mechanical properties of the base material.

[0034] There are versions in which the vent element includes a metal bursting membrane.

[0035] Rupture membranes can be used in various technical systems, including battery cells, to rupture when the pressure difference between the membrane's sides exceeds a threshold, thus releasing the pressure. They consist of a thin material designed to yield or break under a specific pressure. This prevents a sudden pressure increase within the system, avoiding potentially hazardous situations such as explosions or structural damage. Rupture membranes are available in a variety of materials and designs to meet the specific requirements of different applications. Their functionality and reliability are crucial for the safety and longevity of the systems in which they are integrated.

[0036] A metal rupture membrane is characterized by its high strength and resistance to extreme temperatures and chemical influences. It can be precisely manufactured to rupture at a precisely defined pressure.

[0037] Some designs incorporate a vent element consisting of a metal frame and a plastic rupture diaphragm, with the metal frame housing the positioning mechanism. The metal frame allows for precise fitting and positioning within the housing element, as it includes the positioning mechanism. A material-bonded process such as welding or brazing can be used to fix the metal frame to the vent opening. These methods ensure a durable and leak-proof connection that meets the safety and reliability requirements of battery cell construction. The use of a metal frame securely holds the rupture diaphragm and guarantees its functionality in the event of an overpressure event.

[0038] The rupture membrane can be made of special plastics tailored to the specific requirements of the application, such as high temperature resistance, chemical resistance, and precise bursting behavior. The rupture membrane can be bonded into the metal frame to ensure a secure and leak-proof connection.

[0039] A battery cell according to the invention comprises the housing element according to one of the previous embodiments.

[0040] These battery cells can be suitable for applications requiring efficient use of space. Typical applications include electric vehicles, portable electronic devices such as smartphones and laptops, and stationary energy storage systems for renewable energy sources. In electric vehicles, the higher energy density can enable greater driving range. Stationary energy storage systems can benefit from the increased capacity, which can facilitate the integration of renewable energy sources into the power grid and improve security of supply.

[0041] A vehicle according to the invention comprises the battery cell according to the above embodiment.

[0042] A vehicle can be a technical means of transport used to move people, goods, or materials from one place to another. It can utilize various drive systems, such as internal combustion engines, electric motors, or alternative propulsion systems. Vehicles are available in different types and designs, which vary depending on the area of ​​application and requirements. On land, possible vehicle types include cars, trucks, buses, motorcycles, bicycles, and trains. At sea, these include ships, boats, yachts, and submarines. In the air, possible vehicle types include airplanes, helicopters, and drones. This diversity enables the use of vehicles in various environments and for different purposes, from personal mobility to industrial and commercial applications. Exemplary embodiments of the invention are now described by way of example and with reference to the accompanying drawing.

[0043] Fig. 1 shows a battery cell according to one embodiment;

[0044] Fig. 2 shows a cross-section through a housing element and a valve element according to an exemplary embodiment;

[0045] Fig. 3 shows a cross-section through a housing element and a valve element according to an exemplary embodiment;

[0046] Fig. 4 shows a cross-section through a housing element and a valve element according to an exemplary embodiment; and

[0047] Fig. 5 shows a vehicle according to one embodiment.

[0048] Fig. 1 shows a battery cell according to one embodiment.

[0049] The battery cell 100 comprises a housing element 101, a cover 102 and a vent element 103.

[0050] The housing element 101 and the cover 102 (as well as another cover on the opposite side of the cover 102, not shown) enclose the energy storage components of the battery cell 100.

[0051] The vent element 103 is arranged on the top side of the housing element 101 and covers a vent opening of the housing element 101. The vent element 103 is fixed there.

[0052] Fig. 2 shows a cross-section through a housing element and a valve element according to an exemplary embodiment.

[0053] The battery cell 100 comprises a housing element 101 and a vent element 103 comprising a positioning device 104.

[0054] The housing element 101 has a uniform thickness throughout its walls. The vent element 103 is attached to the vent opening – shown in cross-section as a break in the wall – of the housing element 101. The vent element 103 incorporates the positioning device 104. The positioning device 104 is formed as a circumferential step. The positioning device 104 positions the vent element 103 in the vent opening and thus in the defined installation position. In this position, the vent element 103 does not need to be secured against slippage by a device when fixing it, for example, by gluing or welding. Here, the vent element 103 acts as a rupture diaphragm. The vent element 103 can also be produced with a constant thickness by pressing in the step (for example, by deep drawing).

[0055] Fig. 3 shows a cross-section through a housing element and a valve element according to an exemplary embodiment.

[0056] The battery cell 100 comprises a housing element 101 and a vent element 103 comprising a positioning device 104, a metal frame 106 and a burst membrane 105.

[0057] The housing element 101 has the same thickness in all walls. The vent element 103 is attached to the vent opening – shown in cross-section as a break in the wall – of the housing element 101.

[0058] The vent element 103 includes the positioning device 104. The positioning device 104 is formed as a circumferential step in the metal frame 106. The positioning device 104 positions the vent element 103 in the vent opening and thus in the defined installation position. In this position, the vent element 103 does not need to be secured against slippage by means of a device when fixing it, for example by gluing or welding.

[0059] The bursting membrane 105, for example made of plastic, is inserted and fixed to the metal frame 106, for example by means of adhesive. An additional circumferential step can be provided on the metal frame for this purpose.

[0060] Fig. 4 shows a cross-section through a housing element and a valve element according to an exemplary embodiment.

[0061] The battery cell 100 comprises a housing element 101 and a vent element 103 comprising a positioning device 104. The housing element 101 has the same thickness in all walls. The vent element 103 is located at the vent opening – shown in cross-section as a break in the wall – of the housing element 101.

[0062] The vent element 103 includes the positioning device 104. The positioning device 104 is, for example, shaped as a circumferential lip or spring. Furthermore, the positioning device 104 need not be circumferential. The illustration can also show a cross-section through two pins. The positioning device 104 positions the vent element 103 in the vent opening and thus in the defined installation position. In this position, the vent element 103 does not need to be secured against slippage by a device when fixing it, for example, by gluing or welding. Here, the vent element 103 serves as a bursting diaphragm.

[0063] Fig. 5 shows a vehicle according to one embodiment.

[0064] Vehicle 200 comprises a battery consisting of at least one battery cell 100. Based on the installation position of battery cell 100, this vehicle is a car with an electric motor as its drive system. However, integrating battery cell 100 into any of the other vehicles mentioned above is possible.

[0065] Reference numeral list Battery cell Housing element Cover Vent element Positioning device Burst membrane Metal frame Vehicle

Claims

Patent claims 1. Housing element (101) for a battery cell (100), which is manufactured in one piece and has the same wall thickness on four sides, comprising: a vent element (103) which is fixed to a vent opening in the housing element, wherein the vent element (103) comprises a positioning device (104) which ensures positioning in a defined installation position.

2. Housing element (101) according to claim 1, wherein the housing element (101) is made of aluminium.

3. Housing element (101) according to one of the preceding claims, wherein the housing element (101) is a cell cup.

4. Housing element (101) according to one of the preceding claims, wherein the positioning device (104) is a circumferential centering stage that centers the vent element (103) at the vent opening.

5. Housing element (101) according to one of the preceding claims, wherein the vent element (103) is fixed to the vent opening in a materially bonded manner.

6. Housing element (101) according to claim 5, wherein the vent element (103) is fixed to the vent opening by means of welding.

7. Housing element (101) according to one of the preceding claims, wherein the vent element (103) comprises a burst membrane made of metal.

8. Housing element (101) according to one of the preceding claims, wherein the vent element (103) comprises a metal frame and a plastic burst membrane, wherein the metal frame comprises the positioning device (104).

9. Battery cell (100) comprising the housing element (101) according to any of the preceding claims.

10. Vehicle (200) comprising the battery cell (100) according to claim 9.

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