Batteries, energy storage devices, and vehicles

Abstract

A battery (1) comprising an electrochemical cell and a cell housing (2) encapsulating the electrochemical cell. The battery (1) further comprises a gas release device (15) configured to reduce a possible pressure difference between an interior of the cell housing (2) and an atmospheric environment surrounding the cell housing (2). The gas release device (15) comprises one or more membranes (18, 28) having a ratio of carbon dioxide permeability to oxygen permeability at room temperature equal to or higher than 3. The battery (1) can be comprised in an energy storage device (50) and / or a vehicle (100).

Description

Technical Field

[0001] This disclosure relates entirely to a battery. This disclosure also relates entirely to an energy storage device comprising multiple batteries. Furthermore, this disclosure also relates entirely to a vehicle comprising the aforementioned batteries. Background Technology

[0002] The battery comprises an electrochemical cell unit, which may be formed from electrode assemblies and a liquid electrolyte. The electrode assemblies are typically manufactured by laminating or otherwise attaching multiple layers to each other. These multiple layers include electrode layers; more specifically, at least one negative electrode layer and at least one positive electrode layer. The negative and positive electrode layers are then separated from each other by a porous separator layer. The separator layer is configured to contain the electrolyte and prevent short circuits between the electrode layers. Depending on the desired configuration of the battery, the electrode assemblies may, for example, be wound, stacked, or folded to allow the electrochemical cell unit to have as many electrode surfaces as possible within a given available space, and are then placed in a cell housing configured to protect the electrochemical cell unit from the surrounding atmospheric environment. Subsequently, the electrolyte is filled into the cell housing via electrolyte filling pores, ultimately sealing it. The electrolyte is electrically insulating but ionicly conductive, allowing ions to move between the negative and positive electrodes through the electrochemical cell unit.

[0003] A crucial step in battery production is the final process, which establishes the final electrochemical cell chemistry. This process, known as formation and aging (F&A), is performed after the battery has been constructed and filled with electrolyte. During this process, the battery's electrochemical cells undergo slow charge and discharge cycles, followed by repeated charge / discharge cycles, typically at varying rates, with rest periods between charge and discharge (and vice versa). The F&A process is associated with high costs, such as being time-consuming, requiring individual processing for each cell, and necessitating a highly controlled atmospheric environment (at least if the battery is not pre-sealed completely). The formation and aging process generates gases inside the casing, which must be purged before the battery is finally permanently sealed. These gases may be generated due to electrolyte decomposition or through chemical reactions involving oxygen released from the material of at least one electrode. Gas trapped between adjacent electrode assembly pieces can cause stress on the internal components of the battery, leading to higher internal resistance. Furthermore, the generated gases increase the internal pressure within the casing, which can accelerate capacity decay during use. Therefore, the generation of gases inside the battery can lead to a significant reduction in battery life and performance.

[0004] US 2013 / 0130079 A1 proposes a solution to the problem of gas generation during manufacturing. The opening of the battery casing is provided with a first seal that displaces or deforms due to the pressure difference between the inside and outside of the casing. This is achieved by the following method: when the internal pressure in the casing is higher than the external pressure, the first seal is compressed by the internal pressure to allow internal air to escape from the opening; and when the internal pressure in the casing is lower than the external pressure, the first seal is compressed by the external pressure to prevent external air from entering from the opening. The pressure in the space enclosed by the casing and the first seal is set to be lower than the pressure outside the space. Therefore, the first seal essentially acts as a one-way valve during the final stages of battery production. After venting, the opening is completely and hermetically sealed.

[0005] However, gases may also be generated inside the casing after production, i.e., during battery use. This has the same negative impact as the gases generated during the F&A process mentioned above. Therefore, it is desirable to be able to vent gases generated during battery use, as well as potential residual gases generated during the F&A process that may not have been adequately vented previously.

[0006] Modern batteries are typically equipped with a safety valve configured to rupture and release gas if the internal pressure within the battery becomes too high. This reduces the risk of explosion and thus improves safety. However, when the safety valve ruptures, the electrochemical cell is also destroyed, and the battery becomes unusable. Therefore, this type of solution cannot be used to extend battery life or maintain battery performance. Summary of the Invention

[0007] The purpose of this invention is to improve battery life and performance.

[0008] This objective is achieved through the subject matter of the appended independent claims.

[0009] The battery described herein includes an electrochemical battery cell, which in turn includes an electrode assembly and an electrolyte. The battery also includes a battery cell housing that encapsulates the electrochemical battery cell. The battery further includes a gas release device configured to reduce the pressure difference between the interior of the battery cell housing and the surrounding atmospheric environment. The gas release device includes one or more membranes having a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at room temperature.

[0010] The gas release device of the battery according to this disclosure enables the release of gases that were not completely vented during battery manufacturing and / or generated during battery use from inside the casing, while preventing air from entering the battery cell casing from the surrounding atmosphere. This is achieved by a gas release device comprising at least one membrane, which has a significantly higher permeability to carbon dioxide than oxygen. Although the pressure inside the battery cell casing is typically at least slightly higher than the pressure outside the battery cell casing, efforts must still be made to minimize the risk of oxygen from the surrounding atmosphere permeating into the electrochemical battery cells inside the battery cell casing. By allowing the gases generated inside the battery cell casing to escape into the surrounding atmosphere, the battery performance can be maintained for a longer period of time, thereby extending its lifespan.

[0011] At room temperature, one or more membranes may suitably have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 5, or even equal to or greater than 8. The ability of one or more membranes to release carbon dioxide from the interior while preventing oxygen from entering the battery cell housing increases with the increase of the carbon dioxide permeability to oxygen permeability ratio. Therefore, a higher carbon dioxide permeability to oxygen permeability ratio is desirable.

[0012] At temperatures up to at least 100°C, preferably up to at least 150°C, one or more membranes may suitably have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3. Battery temperature tends to rise during charge-discharge cycles, and it is therefore desirable to maintain the aforementioned ratio at higher temperatures.

[0013] The gas release device can be arranged to extend above the electrolyte injection port of the battery cell housing. especially It offers the following advantages: It eliminates the need to form a separate orifice in the battery cell housing for gas release devices, which increases the risk of potential manufacturing errors, such as air leakage into the battery cell housing over time, thus compromising the controlled atmospheric environment within the electrochemical battery cell. Furthermore, it reduces production costs by decreasing the number of through-holes that need to be formed in the battery cell housing. As stated above, by utilizing the electrolyte injection orifice, a separate orifice for gas release devices is unnecessary. It also avoids the need for pre-existing orifices with different dedicated functions during the battery cell's lifespan to be used for dual functions, which would reduce the effectiveness of both functions. For example, if the membrane were to be incorporated into a burst valve used as a safety valve and configured to open under pressure, the design would be complex, and each function would be compromised due to insufficient optimization.

[0014] A gas release device may be arranged within a sealing device configured to seal an electrolyte injection port. The sealing device may be arranged to extend over and / or at least partially into the electrolyte injection port. Therefore, the sealing device may be arranged within or inside the electrolyte injection port, or extend into the electrolyte injection port. Alternatively, the sealing device is arranged to extend over the electrolyte injection port, i.e., to cover the electrolyte injection port. Alternatively, the sealing device may be arranged both in and over the electrolyte injection port, i.e., to cover the electrolyte injection port. The sealing device may include one or more sealing members. The sealing device may, for example, include two sealing members, a first sealing member and a second sealing member. The first sealing member may, for example, be a sealing pin, a sealing ball, or a sealing plate. The second sealing member may, for example, be a sealing pin, a sealing ball, or a sealing plate.

[0015] This has the particular advantage of simplifying the production process, as the gas release device can be placed in the sealing device before the sealing device is placed on the battery, for example, in and / or above the electrolyte injection port.

[0016] The sealing device may, for example, include a sealing pin device. In this case, the sealing pin device may include a gas release device. Therefore, the battery may include a sealing pin device disposed in and / or above the electrolyte injection port. This provides the function of a gas release device in a convenient and efficient manner.

[0017] The sealing pin device may include a first sealing pin configured to be disposed within / inside the electrolyte injection port, thereby sealing the electrolyte injection port. The first sealing pin may include a gas release device. Thus, the function of the gas release device is incorporated into the first sealing pin sealing the electrolyte injection port, thereby providing both a sealing function and a gas release function of the gas release device in a convenient and practical manner. This is also advantageous because a gas leak test can be performed on the first sealing pin, thereby avoiding the use of redundant seals.

[0018] The sealing pin device may additionally include a second sealing pin or sealing plate configured to cover the first sealing pin and seal the electrolyte injection port. Therefore, the second sealing pin or sealing plate can serve as a redundant seal for the electrolyte injection port. In this case, a gas release device can be arranged in both the first and second sealing pins or sealing plates. Thus, the first sealing pin may include a first gas release device, and the second sealing pin or sealing plate may include a second gas release device. This provides redundant sealing, thereby providing the aforementioned gas release function in a convenient and practical manner.

[0019] Furthermore, the gas release device can be at least partially arranged in a through-hole of the battery cell housing. For example, this allows one or more membranes to be arranged closer to the electrolyte within the battery cell housing, thereby enabling faster pickup of gaseous substances from inside the battery cell housing via surface absorption, followed by transport through the one or more membranes. In other words, the gaseous substances need to travel a shorter distance before being picked up by the surface of the one or more membranes. Optionally, the through-hole of the battery cell housing can be an electrolyte injection port for the battery cell housing.

[0020] The gas release device may also include a cover configured to protect one or more membranes from mechanical impact. This, in turn, facilitates, for example, the handling of the battery, and thus facilitates the installation of the battery in the intended application without the risk of damaging one or more membranes.

[0021] At least one of the membranes may contain polyvinylidene chloride (PVDC) or polytetrafluoroethylene (PTFE). Both PVDC and PTFE have the advantage of being able to act as oxygen barriers but with high permeability to carbon dioxide. Furthermore, both PVDC and PTFE are thermally stable within the battery's operating temperature range and are resistant to the chemical environment within the battery cell casing.

[0022] Alternatively, at least one of the membranes may contain perovskite. Membranes containing perovskite may be associated with higher costs than membranes containing polyvinylidene chloride or polytetrafluoroethylene. However, perovskite has the advantage of allowing for highly customized permeability characteristics and generally remains stable over a wide range of chemical environments and temperatures.

[0023] If necessary, the gas release device may also include a moisture-absorbing component. This reduces the risk of moisture entering the battery cell housing and electrochemical cell environment via the gas release device, which could otherwise damage the electrochemical cell and / or lead to further gas generation during charging / discharging.

[0024] According to one embodiment, the gas release device may include two membranes. If so, the aforementioned moisture-absorbing member (if present) can be inserted between the two membranes. especially It has the advantage of preventing moisture from reaching the innermost parts of both membranes and the interior of the battery cell housing. Furthermore, if needed, the moisture-absorbing component can be used as a support structure for one or both membranes.

[0025] The battery may also include a safety valve configured to rupture when the pressure inside the battery cell housing is equal to or higher than a pressure threshold. This has the advantage of increased safety in situations where the gas release device will be unable to vent a sufficient amount of gas, such as during thermal runaway.

[0026] The battery may be, for example, a lithium-ion battery, but is not limited to this. When the battery is a lithium-ion battery, the electrode assembly may contain nickel-containing electroactive materials. Previously known lithium-ion batteries containing nickel-containing electroactive materials have the advantages of increased operating voltage and high energy density, making them well-suited for applications such as the automotive industry. However, compared to other conventional lithium-ion batteries, lithium-ion batteries containing such electroactive materials also exhibit a higher tendency to generate gas during charging / discharging. However, with the battery described herein that allows gas release via a gas release device, such electroactive materials can be used without the risk of reduced performance and / or lifespan. In other words, the battery described herein improves the performance and lifespan of lithium-ion batteries containing nickel-containing electroactive materials.

[0027] In the case where the battery is a lithium-ion battery containing nickel-containing electroactive materials, the total gas permeability of one or more membranes of the gas release device to carbon dioxide can be, for example, 1 mMol to 12 mMol per liter of battery cell housing internal volume per year, preferably 2 mMol to 8 mMol per liter of battery cell housing internal volume per year.

[0028] This disclosure also relates to an energy storage device comprising a plurality of batteries connected in series and / or in parallel, wherein at least one of the plurality of batteries constitutes a battery as described above. The energy storage device may, for example, be a battery module or a battery pack. According to another alternative, the energy storage device may include a plurality of battery packs connected in series and / or in parallel. Where the energy storage device is a battery pack or includes a battery pack, the battery pack may optionally include a plurality of battery modules connected in series and / or in parallel. A battery module may, for example, include at least five batteries, wherein each battery may be a battery as described herein that includes a gas release device.

[0029] Energy storage devices can be used, for example, to power one or more propulsion units of a vehicle, each of which constitutes an electric motor.

[0030] This disclosure also relates to a vehicle comprising the aforementioned battery. The battery may, for example, be included in an energy storage device as described above. The vehicle may be an all-electric vehicle, a hybrid vehicle, or a fuel cell vehicle. Furthermore, the vehicle may be a land-based heavy-duty vehicle, such as a truck or bus, but is not limited thereto. The vehicle may, for example, be a land-based medium-duty vehicle or a car. Alternatively, the vehicle may be a boat or an aircraft. Attached Figure Description

[0031] Figure 1 A perspective view illustrating an example of a previously known battery is shown. Figure 2A perspective view illustrating an example of a previously known battery is shown, wherein a portion of the battery cell housing has been omitted for the purpose of illustrating the battery's electrode assembly. Figure 3 A perspective view illustrating an exemplary embodiment of a battery according to the present disclosure is shown. Figure 4 A cross-sectional view of a first exemplary embodiment of a gas release device for a battery according to the present disclosure is schematically illustrated. Figure 5 A cross-sectional view of a second exemplary embodiment of a gas release device for a battery according to the present disclosure is schematically illustrated. Figure 6 A cross-sectional view of a third exemplary embodiment of a gas release device for a battery according to the present disclosure is schematically illustrated. Figure 7 A cross-sectional view of a fourth exemplary embodiment of a gas release device for a battery according to the present disclosure is schematically illustrated, and Figure 8 A side view illustrating an example of a vehicle that may include the batteries described herein. Detailed Implementation

[0032] The invention will now be described in more detail with reference to exemplary embodiments and the accompanying drawings. However, the invention is not limited to the exemplary embodiments discussed and / or shown in the drawings, but may vary within the scope of the appended claims. Furthermore, the drawings should not be considered to be drawn to scale, as some features may have been enlarged to illustrate the invention or its features more clearly.

[0033] When a range is given in this disclosure, unless otherwise expressly disclosed, the range shall be considered to include the specified end value of the range.

[0034] Energy storage devices for vehicles require numerous electrochemical cell units to achieve the desired capacity. Therefore, energy storage devices for vehicles may, for example, comprise one or more battery packs. Each battery pack may further comprise multiple battery modules, each battery module comprising multiple individual cells (sometimes also called cell units). Battery modules may be connected in series and / or in parallel. Within each module, the cells may be arranged in a two-dimensional or three-dimensional array and may be connected in series and / or in parallel. Each cell further comprises an electrochemical cell unit. Currently, this is the most commonly used battery in energy storage devices for vehicles. It is a rechargeable lithium-ion battery. Depending on, for example, the geometry of the electrochemical cell, the battery can be classified as a cylindrical cell / battery, a prismatic cell / battery, or a pouch cell / battery.

[0035] Generally, cylindrical battery cells can be produced faster and therefore at a lower cost compared to prismatic battery cells. However, prismatic battery cells typically allow for higher capacity and more efficient space utilization due to their shape, a significant factor in the automotive industry. Furthermore, prismatic battery cells offer the advantage of higher capacity because they can be stacked better in their rigid casings compared to pouch cells with flexible housings. Additionally, prismatic battery cells are generally less susceptible to damage from high temperatures and humidity compared to pouch cells. Therefore, prismatic battery cells are commonly used in energy storage devices for vehicles, particularly heavy-duty vehicles.

[0036] This disclosure relates to a battery that can be incorporated into an energy storage device in a vehicle as described above. However, it should be noted that the battery described herein can also be used in other applications. Examples of such applications include, for example, stationary energy storage devices for storing solar or wind energy, or other off-grid energy storage solutions for various purposes. The battery can also be used in various consumer-related applications if desired.

[0037] The battery according to this disclosure includes an electrochemical battery cell, which in turn includes an electrode assembly and an electrolyte. The electrolyte may be a liquid electrolyte. The electrode assembly includes at least one negative electrode, at least one positive electrode, and a separator disposed between the negative and positive electrodes. The electrode assembly may, for example, be wound into a so-called jelly roll or folded. The battery may suitably be a prismatic battery, but may alternatively be a cylindrical battery or a pouch battery. The battery may suitably be a secondary battery, i.e., a rechargeable battery.

[0038] The battery also includes a battery cell housing arranged to encapsulate an electrochemical battery cell. At least a portion of the inner surface of the battery cell housing is typically in direct contact with the electrolyte. The battery also includes battery terminals disposed on the exterior of the battery cell housing, which are electrically connected to electrode assemblies. The battery terminals allow the battery to be electrically connected to one or more adjacent batteries and / or electrical devices.

[0039] The battery described herein also includes a gas release device configured to reduce the temperature difference between the interior of the battery cell housing and the surrounding atmospheric environment. Possible pressure difference. More specifically, the gas release device is configured to reduce the pressure difference by releasing gases generated during battery charging and / or discharging from the electrochemical battery cell environment to the outside of the battery cell housing. For this purpose, the gas release device includes (or is composed of) one or more membranes configured to allow gases to pass from the inside of the battery cell housing to the surrounding atmospheric environment outside the battery cell housing. Gases generated during the battery's charge-discharge cycle include carbon dioxide, and therefore it is important that carbon dioxide can pass through one or more membranes of the gas release device. Furthermore, it is important to prevent oxygen from entering the inside of the battery cell housing, as this could lead to an increased risk of gas generation inside the battery cell housing due to chemical reactions during charging and discharging. Therefore, one or more membranes of the gas release device are selected to have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at room temperature.

[0040] The ability of one or more membranes to release carbon dioxide from the interior while suppressing oxygen from entering the battery cell housing increases with the increase of the ratio between carbon dioxide permeability and oxygen permeability. Therefore, one or more membranes may suitably have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 5 at room temperature, or even equal to or greater than 8 at room temperature.

[0041] The permeability of one or more membranes to carbon dioxide and oxygen is influenced by the choice of materials, the surface area exposed inside the battery cell housing, and the thickness of one or more membranes, respectively. In this disclosure, the thickness of one or more membranes is considered to refer to the dimension of the one or more membranes extending in a direction perpendicular to the surface of the one or more membranes directly exposed to the environment inside the battery cell housing. In the case where the gas release device includes multiple membranes, these membranes may be suitably arranged parallel to each other. Furthermore, in the presence of multiple membranes, each membrane may be arranged to be in direct contact with an adjacent membrane, or it may be arranged to be at a distance from an adjacent membrane.

[0042] Furthermore, the temperature of one or more membranes (which can be affected by ambient temperature) can also influence permeability. During charging and discharging, the temperature inside the battery cell casing can rise, and temperatures as high as approximately 60°C can occur relatively frequently in conventional lithium-ion batteries used in the automotive industry. Therefore, one or more membranes can be appropriately selected to have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at temperatures up to at least 100°C, or even up to at least 150°C.

[0043] Appropriately, one or more membranes may be selected to have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 5 at temperatures up to at least 100°C.

[0044] A gas release device may be arranged to extend above a through-hole in the battery cell housing and / or at least partially within the through-hole. In some cases, the through-hole may be an electrolyte injection port (sometimes also referred to as an electrolyte filling port) of the battery cell housing. Arranging the gas release device at the electrolyte injection port has the advantage of reducing the number of through-holes that need to be manufactured in the battery cell housing. This reduces the risk of air leakage into the battery cell housing due to possible manufacturing defects during battery production. However, in some cases, it may be desirable to install the gas release device into the battery cell housing before introducing the electrolyte during battery production, or it may be desirable to have an electrolyte injection port of a smaller size than is required for the membrane region exposed inside the battery cell housing. In such cases, a separate through-hole in the battery cell housing may be required for the gas release device.

[0045] A gas release device may be arranged in a sealing device configured to seal an electrolyte injection port. The sealing device may be configured to seal the electrolyte injection port after electrolyte has been injected into the battery cell. The sealing device may be arranged to extend over and / or at least partially into the electrolyte injection port. The sealing device may alternatively or additionally be arranged inside the electrolyte injection port. The sealing device may include one or more sealing members, such as two sealing members. The sealing device may include, for example, two sealing members, a first sealing member and a second sealing member. The first sealing member may be, for example, a sealing pin, a sealing ball, or a sealing plate. The second sealing member may be, for example, a sealing pin, a sealing ball, or a sealing plate.

[0046] The production process is greatly simplified by providing a gas release device in the sealing device configured to seal the electrolyte injection port.

[0047] The sealing device may, for example, include a sealing pin device. In this case, the sealing pin device may include a gas release device. Therefore, the battery may include a sealing pin device disposed in and / or extending above the electrolyte injection port. This provides the function of a gas release device in a convenient and efficient manner.

[0048] The sealing pin device may include a first sealing pin configured to be disposed within the electrolyte injection port, thereby sealing the electrolyte injection port. Therefore, the first sealing pin can be the first sealing member of the sealing device. The first sealing pin may include a gas release device. Thus, the function of the gas release device is incorporated into the first sealing pin sealing the electrolyte injection port, thereby providing both a sealing function and a gas release function of the gas release device in a convenient and practical manner. This eliminates the need for redundant seals, as it improves or simplifies gas leak testing.

[0049] The sealing pin device may additionally include a second sealing pin or sealing plate configured to cover the first sealing pin and seal the electrolyte injection port. Therefore, the second sealing pin or sealing plate can serve as a redundant seal for the electrolyte injection port. In this case, a gas release device can be arranged in both the first sealing pin and the second sealing pin or sealing plate. Thus, the first sealing pin may include a first gas release device, and the second sealing pin or sealing plate may include a second gas release device. This provides redundant sealing, thereby providing the aforementioned gas release function in a convenient and practical manner.

[0050] In addition to one or more membranes, the gas release device may also include a retainer to which the one or more membranes are hermetically joined or otherwise attached. If desired, such a retainer may serve to facilitate installation of the gas release device in the battery during production and / or to provide structural stability to the one or more membranes during battery use. However, it should be noted that, if desired, the one or more membranes may alternatively be attached directly to the battery cell housing, for example, by an adhesive. In this case, the gas release device may consist of one or more membranes.

[0051] To protect one or more membranes during battery production, handling, or installation and use in the intended application, the gas release device may also include a cover configured to protect the one or more membranes from mechanical impact. Naturally, such a cover may include one or more openings configured to allow gas to be released into the surrounding atmosphere. The cover may suitably be made of a metallic material, such as the same material used in the battery cell housing.

[0052] One or more membranes have an inner surface facing the interior of the battery cell housing, thus exposing it directly to the battery's internal atmospheric environment. Typically, this inner surface corresponds to the inner surface of a single membrane among the one or more membranes. The inner surface of the one or more membranes may, for example, have an 8mm diameter. 2 Up to 35mm 2 The area.

[0053] Appropriately, the inner surface may have a thickness of 10 mm. 2 Up to 30mm 2The area of ​​the membrane. Furthermore, one or more membranes may have a total thickness of, for example, from 2 mm to 10 mm (i.e., the total extension dimension in the direction perpendicular to the inner surface of the one or more membranes). Suitablely, one or more membranes may have a total thickness of 3 mm to 8 mm. However, this disclosure is not limited to the exemplary inner surface area and total thickness described above, and other dimensions are also reasonable. As previously mentioned, permeability is affected by the area and thickness of one or more membranes, as well as the choice of material for one or more membranes. Therefore, the dimensions of one or more membranes should be appropriately adjusted according to the material selected for one or more membranes.

[0054] Each of the one or more membranes may be made of a polymer-based material. For example, one or more membranes in a gas release device may suitably comprise or be composed of polyvinylidene chloride (PVDC). According to another alternative, one or more membranes may comprise or be composed of polytetrafluoroethylene (PTFE). Both PVDC and PTFE enable carbon dioxide permeability to be much higher than oxygen permeability and can form membranes suitable for the dimensions of the gas release device according to this disclosure.

[0055] Alternatively, each of the one or more membranes may be formed of an inorganic material. For example, at least one of the one or more membranes may be a perovskite membrane. Perovskite can be described as a mixed metal oxide having a well-defined cubic structure and the general formula ABO3, wherein A is at least one alkaline earth or lanthanide element, and B is at least one transition metal. The permeability of perovskite to various gaseous compounds can be tailored by adjusting the metal sites in the structure.

[0056] To reduce the risk of moisture entering the electrochemical cell environment, the gas release device may also include a moisture-absorbing component, if desired. The moisture-absorbing component may be in the form of a porous material comprising, or composed of, zeolite, silica gel, or activated alumina. The moisture-absorbing component may, for example, be arranged interposed between the two membranes of the gas release device, but other arrangements of the moisture-absorbing component are also possible.

[0057] When the membrane is formed of a polymer-based material, such as when polyvinylidene chloride or polytetrafluoroethylene is included, the permeability of oxygen and carbon dioxide through at least one membrane can be measured, for example, according to ISO 15105.

[0058] When at least one membrane contains perovskite, the permeability of oxygen and carbon dioxide can be determined by gas chromatography, respectively.

[0059] While the aforementioned gas release device is configured to reduce the pressure difference between the battery cell housing and the surrounding atmosphere, there is a risk that the pressure inside the battery cell housing may increase rapidly due to factors such as thermal runaway. Therefore, the battery described herein may also suitably include a safety valve configured to break when the pressure inside the battery cell housing equals or exceeds a critical pressure threshold. Such a safety valve is known in the past and will therefore not be described in more detail in this disclosure. When such a safety valve breaks, the internal pressure of the battery decreases rapidly, thus improving safety. However, given that the electrochemical battery cell environment is not protected, the battery may become unusable.

[0060] The battery according to this disclosure may be, for example, a lithium-ion battery. The battery described herein may be, for example, a lithium-ion battery in which the electrode assembly comprises a nickel-containing electroactive material. Lithium-ion batteries containing nickel-containing electroactive materials in the positive electrode are particularly attractive to the automotive industry due to their high energy density and operating voltage. Examples of such nickel-containing electroactive materials include lithium nickel manganese cobalt oxide, commonly abbreviated as NMC, having the general formula LiNi. x Mn y Co 1-x-y O2.

[0061] The generation of gases in the electrochemical cell of a battery is influenced by several factors, such as the electroactive materials used (including their composition and particle size), the composition of the electrolyte (including additives), the size of the battery, and the charge / discharge rate it experiences. Therefore, the total expected permeability of one or more membranes in a gas release device to carbon dioxide can vary. However, as an example, for a lithium-ion battery containing a nickel-containing electroactive cathode material as described above, the total gas permeability of one or more membranes to carbon dioxide can be from 1 mmol / L of battery cell internal volume per year to 12 mmol / L of battery cell internal volume per year (at least at room temperature). Suitablely, the total gas permeability of one or more membranes to carbon dioxide can be from 2 mmol / L to 8 mmol / L of battery cell internal volume per year (at least at room temperature). Since the gas escape and the resulting internal pressure are related to the total amount of electroactive material in the electrochemical cell and the dead volume in the battery cell housing, the above values ​​are normalized relative to the internal volume of the battery cell housing. As a metric typically used to optimize total cell energy and electroactive materials during battery cell design.

[0062] However, it should be noted that this disclosure is not limited to lithium-ion batteries. The batteries described herein may alternatively be sodium-ion or potassium-ion batteries, for example.

[0063] This disclosure also relates to an energy storage device comprising a plurality of batteries, wherein at least one of the plurality of batteries constitutes a battery according to this disclosure. The plurality of batteries in the energy storage device may be connected in series and / or in parallel. In the energy storage device, the plurality of batteries may be arranged in one or more battery modules if desired. Each such battery module may include a module housing, or another form of mechanical structure configured to hold the battery in proper position within the module. When the energy storage device comprises multiple modules, these modules may be connected in series and / or in parallel.

[0064] Figure 1 A perspective view illustrating an example of a previously known battery 1' is shown. Battery 1' includes a battery cell housing 2 configured to encapsulate an electrochemical battery cell comprising electrode components and an electrolyte. The battery cell housing 2 of the exemplary battery 1' has a substantially rectangular construction and is typically made of a rigid metallic material, such as an aluminum-based material. This type of battery is commonly referred to in the art as a prismatic battery. especially It has the advantage of allowing batteries to be stacked closely together, such as in battery modules or battery packs.

[0065] The first battery terminal 3 and the second battery terminal 4 are shown arranged on one side of the battery cell housing 2, more specifically at the top plate 2a of the battery cell housing 2. However, it should be noted that, if desired, the first battery terminal 3 and the second battery terminal 4 may alternatively be arranged on opposite sides of the battery.

[0066] Battery terminals 3 and 4 are electrically connected to the corresponding electrodes of the electrode assembly arranged inside the battery cell housing 2. The electrode assembly, together with the liquid electrolyte, forms an electrochemical battery cell. After the electrode assembly has been arranged in the battery cell housing 2 and the battery cell housings have been welded together, the electrolyte is typically introduced into the battery cell housing 2 through the electrolyte injection port 5 in the battery cell housing 2. The electrolyte injection port 5 is then sealed.

[0067] The exemplary battery 1' also includes a safety valve 6 disposed within the battery cell housing 2. The safety valve 6 is configured to rupture if the pressure within the battery cell housing 2 increases above a critical threshold, thereby releasing gas from the interior of the battery cell housing 2. When the safety valve 6 has ruptured, the electrochemical battery cell is no longer sealed to the surrounding atmosphere. This means that the battery 1' may become unusable. The primary purpose of the safety valve 6 is to prevent an explosion due to a significant increase in pressure within the battery cell housing 2 (e.g., due to thermal runaway within the battery cell housing 2).

[0068] Figure 2 Examples of previously known batteries (such as...) Figure 1The diagram shows a perspective view of an example of battery 1', but the upper portion of the battery cell housing 2 (including the top plate of the battery cell housing 2) and components attached to or otherwise arranged at the top plate have been removed, making the electrode assembly 8 of the electrochemical battery cell visible. The electrode assembly 8 is shown in the figure as rolled into a so-called square core. However, the electrode assembly may alternatively be a stacked electrode assembly or a Z-folded electrode assembly.

[0069] exist Figure 2 On the right-hand side, a schematic cross-sectional view of the electrode assembly 8 (single turn) according to this example is shown in more detail. The electrode assembly 8 comprises multiple layers that may be laminated or otherwise attached to each other to form a sandwich structure. More specifically, the electrode assembly 8 comprises a first electrode layer 9, a first diaphragm layer 10, a second electrode layer 11, and a second diaphragm layer 12, or is composed of the latter. The first electrode layer 9 may be a negative electrode, and the second electrode layer 11 may be a positive electrode, and vice versa. The first diaphragm layer 10 is disposed between the first electrode layer 9 and the second electrode layer 11. As shown, the second diaphragm layer 12 may be disposed outside the second electrode layer 11 in the electrode assembly 8. In other words, the second electrode layer 11 may be disposed between the first diaphragm layer 10 and the second diaphragm layer 12. Alternatively, the second diaphragm layer 12 may be disposed outside the first electrode layer 9, such that the first electrode layer 9 is disposed between the first diaphragm layer 10 and the second diaphragm layer 12.

[0070] The first electrode layer 9 may further include two first sublayers 9a and a second sublayer 9b bonded together. A second sublayer 9a constituting a current collector is disposed between the two first sublayers 9a. Each of the first sublayers 9a contains a first electroactive material. Similarly, the second electrode layer 11 includes two first sublayers 11a, each of which contains a second electroactive material. It also includes a second sublayer 11b bonded to each of the first sublayer 11a. The second sublayer 11b of the second electrode layer constitutes a current collector.

[0071] The first electrode layer 9 and the second electrode layer 11 are each attached to a corresponding electrode tap 13, 14 at the respective longitudinal ends of the electrode assembly. These corresponding electrode taps are configured to electrically connect the corresponding electrode to its corresponding battery terminal. Figure 1 (Comparison of battery terminals 3 and 4 shown).

[0072] Figure 3 A perspective view illustrating an exemplary embodiment of battery 1 described herein is shown. Battery 1 corresponds to the reference above. Figure 1 and Figure 2The battery 1' described differs in that it also includes a gas release device 15. The gas release device 15 is configured to reduce the pressure difference between the interior of the battery cell housing 2 and the atmospheric environment surrounding the battery 1.

[0073] As shown in the figure, the gas release device 15 can be arranged on the top side of the battery cell housing 2. The top side of the battery cell housing 2 is here considered to refer to the orientation relative to the intended use of the battery. The gas release device 15 can be arranged on the same side of the battery as the safety valve 6. However, if desired, the gas release device can be arranged on the other side of the battery.

[0074] The gas release device 15 is arranged at a through-hole in the battery cell housing 2, but is not visible in the figure. The gas release device 15 is shown in the figure as being arranged at a distance from the electrolyte injection hole 5. However, according to other embodiments of the battery 1 described herein, the gas release device 15 may also be arranged at the electrolyte injection hole 5.

[0075] As shown, the gas release device 15 may have a substantially circular structure. However, this disclosure is not limited thereto, and therefore, the gas release device 15 may have an elliptical structure (compared to the shape of the safety valve 6 of the battery 1) or a rectangular structure.

[0076] Figure 4 A battery (such as) according to this disclosure is schematically illustrated. Figure 3 The diagram shows a cross-sectional view of a first exemplary embodiment of the gas release device 15 of the battery 1, arranged within the battery 1. More specifically, the gas release device 15 is arranged on the outer surface 2b of the battery cell housing 2 and extends above a through-hole 22 in the battery cell housing 2. The through-hole 22 may be an electrolyte injection hole or another through-hole in the battery cell housing 2.

[0077] The gas release device 15 includes a retainer 16, a cover 17, and a membrane 18. The membrane 18 has a surface 18a facing the interior of the battery cell housing 2 and a thickness t. The membrane 18 is configured to allow gas to be released from the interior of the battery cell housing 2 to the surrounding atmosphere outside the battery 1 when the pressure inside the battery cell housing 2 is higher than the external pressure, while preventing oxygen from entering from the outside air. Therefore, the membrane has a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at room temperature. Thus, carbon dioxide from inside the battery cell housing can permeate through the membrane from surface 18a in the direction of the membrane thickness t.

[0078] The retainer 16 and the membrane 18 are arranged such that they together surround the external opening of the through-hole 22 (i.e., the opening of the through-hole 22 as seen in a plane coinciding with the plane of surface 2b). For this purpose, the membrane 18 may be attached to the retainer 16, for example, by an adhesive. The cover 17 is configured to protect the membrane 18 from mechanical impact. Furthermore, in the exemplary embodiment shown, the cover 17 is configured to form a structure together with the retainer 16 and the membrane 18 that completely covers the through-hole 22. Therefore, the cover 17 may be attached to the retainer 16 and the membrane 18, for example, by an adhesive. The retainer 16 and the cover may be made of, for example, a metallic material, but this disclosure is not limited thereto.

[0079] Figure 5 A cross-sectional view schematically illustrating a second exemplary embodiment of the gas release device 15 of the battery according to the present disclosure, arranged in the battery 1. Figure 4 Similar to the first exemplary embodiment shown, the gas release device 15 according to the second exemplary embodiment is arranged on the outer surface 2b of the battery cell housing 2 and extends above the through-hole 22 of the battery cell housing 2. Furthermore, the gas release device 15 includes a retainer 16, a membrane 18, and an optional cover 17. As with the first exemplary embodiment of the gas release device 15 described above, the membrane 18 has a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at room temperature.

[0080] However, compared to Figure 4 In the first exemplary embodiment shown, the membrane 18 extends above the through-hole. Therefore, the surface 18a of the membrane exposed to the environment inside the battery cell housing 2 is arranged substantially parallel to the outer surface 2b of the battery cell housing 2 where the gas release device 15 is arranged. This also means that the membrane has… The thickness t is substantially perpendicular to the surface 2b of the battery cell housing 2. Furthermore, Figure 5 The cover 17 shown is an optional feature and can therefore be omitted if desired.

[0081] The retainer 16 is arranged to surround the outer opening of the through-hole 22 along its entire circumference. The retainer 16 may be attached to the outer surface 2b of the battery cell housing 2, for example, by welding or using an adhesive. The membrane 18 may also be attached to the retainer 16, for example, by using an adhesive. The cover 17 (if present) may be attached to the retainer 16 and / or the battery cell housing 2, for example, by welding or using an adhesive. The cover 17 (if present) surrounds the retainer 16 and the membrane 18. In other words, the cover 17 can be described as forming a cap-like structure over the through-hole 22 and the membrane 18. This protects the membrane 18 from mechanical impact. Optionally, the cover 17 includes at least one through-hole 19, which is configured to allow gas released from inside the battery cell housing 2 and passing through the membrane 18 to be released from the gas release device 15 to the surrounding atmosphere outside the battery 1. The through hole 19 is illustrated in the figure as being arranged in the side wall 17a of the cover 17, which extends from the outer surface 2b of the battery cell housing 2 to the top surface 17b of the cover 17.

[0082] If necessary, a second exemplary embodiment of the gas release device 15 can be modified by omitting the retainer 16. In this case, the membrane 18 can be directly attached to the outer surface 2b of the battery cell housing and / or to the inner surface of the cover 17, for example, by an adhesive. In practice, the gas release device 15 may consist only of the membrane 18, in which case the membrane 18 is directly attached to the battery cell housing 2.

[0083] Figure 6 A cross-sectional view schematically illustrating a third exemplary embodiment of the gas release device 15 of the battery 1 according to the present disclosure, when arranged in the battery 1. (Compared to...) Figure 4 and Figure 5 Similar to the first and second exemplary embodiments shown, the gas release device 15 according to the third exemplary embodiment extends above the through-hole 22 of the battery cell housing 2 and includes a retainer 16 and a membrane 18, the membrane 18 having a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at room temperature. Optionally, the gas release device may also include a cover 17 as shown.

[0084] However, compared to the first and second exemplary embodiments of the gas release device 15, the gas release device 15 is configured to not only be arranged in the through hole The membrane 18 extends above the through-hole 22 and is also located within (at least a portion) of the through-hole 22. More specifically, when the gas release device 15 is arranged in the battery 1, the membrane 18 and the retainer 16 are at least partially arranged within the through-hole 22. As shown, the retainer 16 may have a flanged sleeve construction, wherein the flange extends along the outer surface 2b of the battery cell housing 2. The membrane 18 may also be arranged inside the flanged sleeve.

[0085] As shown in the figure, the optional cover 17 may have a dome-shaped structure including a plurality of through holes 19 through which gas passing through the membrane 18 from inside the battery cell housing 2 can escape into the atmosphere surrounding the battery 1. However, the optional cover 17 does not necessarily have a dome-shaped structure, but may instead have a substantially flat top surface 17b, such as... Figure 5 As shown. Similarly, Figure 5 The cover 17 of the gas release device 15 shown can be used Figure 6 The dome-shaped cover 17 shown is used instead.

[0086] Similar to the second exemplary embodiment, a third exemplary embodiment of the gas release device 15 can be modified by omitting the retainer 16. In this case, the membrane 18 can be attached directly to the battery cell housing, for example, along the circumferential surface of the through-hole 22.

[0087] Figure 7 A cross-sectional view of a fourth exemplary embodiment of the gas release device 15 of the battery according to the present disclosure, arranged in the battery 1, is schematically illustrated. The gas release device 15 according to the fourth exemplary embodiment corresponds to the gas release device 15 of the third exemplary embodiment described above, except that it includes a first membrane 18 and a second membrane 28. As shown, the first membrane 18 and the second membrane 28 may be arranged in parallel. In addition, the gas release device 15 may also include a moisture-absorbing member 24. The moisture-absorbing member 24 may be inserted between the first membrane 18 and the second membrane 28, as shown. However, it should be noted that the moisture-absorbing member 24 may alternatively be arranged outside or inside the first membrane 18 and the second membrane 28, as seen in the direction relative to the interior of the battery cell housing 2.

[0088] If at least one of the first membrane 18 and the second membrane 28 contains perovskite, the moisture-absorbing member 24 can also serve as a support structure (in other words, a carrier) for the perovskite. In this case, the perovskite can be adhered to the moisture-absorbing member 24, for example, using conventional sol-gel techniques.

[0089] It should be noted here that, although Figure 7An example is shown of a gas release device 15 comprising two membranes (i.e., a first membrane 18 and a second membrane 28) and a moisture-absorbing member 24, but the gas release device 15 of the battery 1 according to this disclosure only needs to include one of the first membrane 18 and the second membrane 28, even when the moisture-absorbing member 24 is included.

[0090] Figure 8 A side view of an example of a vehicle 100 is shown, illustrated here as a trailer tractor. Vehicle 100 can be a land-based heavy-duty vehicle, such as a truck or bus, but is not limited thereto. Furthermore, the vehicle can be a fully electric vehicle or a hybrid vehicle.

[0091] The vehicle 100 may include one or more energy storage devices 50, as schematically illustrated by the dashed boxes in the figures. Each of the one or more energy storage devices 50 may be a battery pack comprising a plurality of batteries, wherein one or more of the plurality of batteries may constitute the battery 1 according to the present disclosure. Within the energy storage device 50, the plurality of batteries may be arranged in a plurality of battery modules 40, if desired. The battery described herein may be included in such a battery module 40.

Claims

1. A battery (1), the battery comprising: An electrochemical battery cell unit, the electrochemical battery cell unit including an electrode assembly (8) and an electrolyte; Battery cell housing (2), wherein the battery cell housing encapsulates the electrochemical battery cell; and A gas release device (15) is configured to reduce the pressure difference between the interior of the battery cell housing (2) and the surrounding atmospheric environment. The gas release device (15) includes one or more membranes (18, 28) having a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at room temperature.

2. The battery (1) according to claim 1, wherein the one or more membranes (18, 28) have a carbon dioxide permeability to oxygen permeability ratio of equal to or greater than 5, preferably equal to or greater than 8, at room temperature.

3. The battery (1) according to any one of claims 1 or 2, wherein the one or more membranes (18, 28) have a carbon dioxide permeability to oxygen permeability ratio equal to or greater than 3 at a temperature of up to at least 100°C, preferably at a temperature of up to at least 150°C.

4. The battery (1) according to any one of the preceding claims, wherein the gas release device (15) is arranged to extend above the electrolyte injection port (5) of the battery cell housing (2).

5. The battery (1) according to claim 4, wherein the gas release device (15) is arranged in a sealing device configured to seal the electrolyte injection port (5).

6. The battery (1) according to any one of the preceding claims, wherein the gas release device (15) is at least partially arranged in a through hole (22) of the battery cell housing (2), optionally wherein the through hole (22) constitutes an electrolyte injection hole (5) of the battery cell housing (2).

7. The battery (1) according to any one of the preceding claims, wherein the gas release device (15) further comprises a cover (17) configured to protect the one or more membranes (18, 28) from mechanical impact.

8. The battery (1) according to any one of the preceding claims, wherein at least one of the one or more membranes (18, 28) comprises polyvinylidene chloride or polytetrafluoroethylene.

9. The battery (1) according to any one of the preceding claims, wherein at least one of the one or more membranes (18, 28) comprises perovskite.

10. The battery (1) according to any one of the preceding claims, wherein the gas release device (15) further comprises a moisture-absorbing member (24).

11. The battery (1) according to claim 9, wherein the gas release device (15) comprises two membranes (18, 28) and the moisture-absorbing member (24) is inserted between the two membranes (18, 28).

12. The battery (1) according to any one of the preceding claims, the battery further comprising a safety valve (6) configured to break when the pressure inside the battery cell housing (2) is equal to or higher than a pressure threshold.

13. The battery (1) according to any one of the preceding claims, wherein the battery (1) is a lithium-ion battery.

14. The battery (1) according to claim 13, wherein the electrode assembly (8) comprises a nickel-containing electroactive material.

15. The battery according to claim 14, wherein the total gas permeability of the one or more membranes (18, 28) to carbon dioxide is 1 to 12 mmol per liter of the internal volume of the battery cell housing (2) per year.

16. An energy storage device (50) comprising a plurality of batteries connected in series and / or in parallel, wherein at least one of the plurality of batteries constitutes a battery (1) according to any one of the preceding claims.

17. A vehicle (100) comprising a battery (1) according to any one of claims 1 to 14 or an energy storage device (50) according to claim 16.

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