Battery system and electric device

Abstract

The embodiment of the present disclosure provides a battery system and a power utilization device, and relates to the technical field of batteries. The battery system comprises a battery pack and a controller coupled with the battery pack. The battery pack comprises a first shell and a battery module. The first shell is filled with a first fluid medium, and the battery module is at least partially immersed in the first fluid medium. The battery module comprises a second shell and a battery cell. The second shell is filled with a second fluid medium, and the battery cell is at least partially immersed in the second fluid medium. The controller is used to control the second fluid medium in the second shell to flow into the first shell or control the first fluid medium in the first shell to flow into the second shell, so that at least a first surface of the battery cell bears a given pressure required by the battery cell. The first fluid medium in the inner cavity of the first shell can also achieve thermal management and thermal runaway spread inhibition of the battery cell.

Description

Technical Field

[0001] This disclosure relates to the field of battery technology, and more particularly to battery systems and electrical devices. Background Technology

[0002] With the rapid development of electric vehicles, energy storage power stations, and other fields, high-energy-density, high-power charge-discharge battery packs are widely used. During operation, to ensure the contact quality at the cathode-electrolyte-anode interface of the individual battery cells within the battery pack, thereby reducing resistance, improving high-power charge-discharge performance, and extending cycle life, specific surfaces of the battery cells typically need to be subjected to a certain pressure. Especially during charging and discharging, the battery electrodes expand and contract, potentially causing changes in pressure on specific surfaces of the battery cells, which are generally detrimental. Furthermore, batteries generate a significant amount of heat during operation. If this heat cannot be dissipated in a timely manner, it will lead to increased battery temperature and temperature differences, severely impacting cycle life, charge-discharge efficiency, and safety performance. Summary of the Invention

[0003] At least one embodiment of this disclosure provides a battery system and an electrical device that can ensure that a specific surface of a battery cell is subjected to the required pressure during the operation of the battery system, while at least to a certain extent improving the heat dissipation performance of the battery system.

[0004] According to one aspect of this disclosure, a battery system is provided, including a battery pack and a controller coupled to the battery pack, wherein: the battery pack includes a first housing and a battery module, the first housing being filled with a first fluid medium, the battery module being at least partially immersed in the first fluid medium, wherein the battery module includes a second housing and battery cells, the second housing being filled with a second fluid medium, the battery cells being at least partially immersed in the second fluid medium; the controller is configured to control the flow of the second fluid medium in the second housing into the first housing, or control the flow of the first fluid medium in the first housing into the second housing, to subject at least a first surface of the battery cells to a given pressure.

[0005] In some embodiments, a circulation device is further included, the circulation device being used to control the flow of the first fluid medium in a circulation path, the circulation path including the inner cavity of the first housing, so as to keep the temperature of the battery cell within a preset temperature range.

[0006] In some embodiments, the pressure exerted by the first fluid medium in the first housing on the battery module is less than or equal to the pressure exerted by the second fluid medium in the second housing on the battery cell.

[0007] In some embodiments, the given pressure is higher than atmospheric pressure.

[0008] In some embodiments, the first fluid medium in the first housing is an atmospheric pressure fluid.

[0009] In some embodiments, the battery cell includes a tab disposed on a first side, the first side intersecting the first surface, and the tab is not immersed in a second fluid medium.

[0010] In some embodiments, the tab is immersed in the first fluid medium.

[0011] In some embodiments, the first fluid medium and the second fluid medium have the same composition.

[0012] In some embodiments, the battery system further includes a fluid medium storage device coupled to the circulation device, an inlet control valve and an outlet control valve coupled to the controller and a first housing of the battery pack, wherein the controller is further configured to control the inlet control valve according to state parameters of the first fluid medium and / or the second fluid medium, so as to control the fluid medium drawn by the circulation device from the fluid medium storage device to flow into the first housing through the inlet control valve; the controller is further configured to control the outlet control valve according to state parameters of the first fluid medium and / or the second fluid medium, so as to control the first fluid medium in the first housing to flow back to the fluid medium storage device through the outlet control valve.

[0013] In some embodiments, the state parameters include at least one of pressure, stress, temperature, and flow rate.

[0014] In some embodiments, the internal space of the battery pack is divided into a battery compartment and an electrical component compartment, the battery compartment and the electrical component compartment are sealed and isolated, the battery module is located in the battery compartment, the electrode terminals of the battery pack are located in the electrical component compartment, and the electrode terminals of the battery pack are electrically connected to the tabs of the battery cells.

[0015] In some embodiments, the battery pack further includes a battery mounting bracket, through which the battery module is fixed in the battery compartment.

[0016] In some embodiments, the second housing includes a plurality of cavities for containing a second fluid medium, and the battery cell includes opposing first and second surfaces, wherein the pressure inside the cavity where the first surface is located and the cavity where the second surface is located can vary independently from each other.

[0017] In some embodiments, the first fluid medium and / or the second fluid medium include additives capable of neutralizing harmful substances generated by battery cells.

[0018] In some embodiments, the additive is selected from at least one of diisooctyl monoethanolamine, zinc isooctanoate, amino-modified perfluoropolyether, chloride, sulfate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, and basic inorganic substances.

[0019] In some embodiments, the first fluid medium and the second fluid medium are one or more of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, and fluorinated fluids.

[0020] In some embodiments, both the first fluid medium and the second fluid medium are liquids.

[0021] In some embodiments, the battery cell includes a solid electrolyte.

[0022] In some embodiments, the electrolyte of the battery cell is entirely a solid electrolyte.

[0023] According to another aspect of this disclosure, an electrical device is provided, which includes a battery system as described in any of the above claims, the battery system being used to provide electrical energy. Attached Figure Description

[0024] To more clearly illustrate the technical solutions of the embodiments of this disclosure, the accompanying drawings of the embodiments will be briefly described below. Obviously, the drawings described below only relate to some embodiments of this disclosure and are not intended to limit this disclosure.

[0025] Figure 1 The embodiments of this disclosure illustrate the environments in which the battery system provided can be applied.

[0026] Figure 2 This is a schematic structural diagram of a battery system according to an embodiment of the present disclosure.

[0027] Figure 3 A schematic diagram of a battery system including a cycling device is shown as an example.

[0028] Figure 4 A schematic diagram of the first housing of a battery pack is shown according to an exemplary embodiment.

[0029] Figure 5 according to Figure 3 and Figure 4 An exemplary cross-sectional view of a battery pack is shown.

[0030] Figure 6 A cross-sectional schematic diagram of a battery module is shown according to an exemplary embodiment. Detailed Implementation

[0031] To make the objectives, technical solutions, and advantages of the embodiments of this disclosure clearer, the technical solutions of the embodiments of this disclosure will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of this disclosure. Based on the described embodiments of this disclosure, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of this disclosure.

[0032] Unless otherwise defined, the technical or scientific terms used in this disclosure shall have the ordinary meaning understood by one of ordinary skill in the art to which this disclosure pertains. The terms “first,” “second,” and similar terms used in this disclosure do not indicate any order, quantity, or importance, but are merely used to distinguish different components. Terms such as “comprising” or “including” mean that the element or object preceding the word encompasses the elements or objects listed following the word and their equivalents, without excluding other elements or objects. Terms such as “connected” or “linked” are not limited to physical or mechanical connections, but can include electrical connections, whether direct or indirect. Terms such as “upper,” “lower,” “left,” and “right” are used only to indicate relative positional relationships, and these relative positional relationships may change accordingly when the absolute position of the described objects changes.

[0033] Unless otherwise defined, the features such as "parallel," "perpendicular," and "identical" used in the embodiments of this invention include strictly defined cases of "parallel," "perpendicular," and "identical," as well as cases involving a certain margin of error, such as "approximately parallel," "approximately perpendicular," and "approximately identical." For example, the aforementioned "approximately" may indicate that the difference between the compared objects is within 10% or 5% of the average value of the compared objects. Unless otherwise specified in the following embodiments of this invention, the quantity of a component or element is implied; it means that the component or element may be one or more, or can be understood as at least one. "At least one" refers to one or more, and "more" refers to at least two.

[0034] Figure 1 The examples illustrate environments in which the battery system provided in the embodiments of this disclosure can be applied. For example... Figure 1The illustrated power device 10 may include a battery system 102, which can be used to provide electrical energy to the power device 10. In some embodiments, the power device 10 may be a device that requires high power and high current driving force, such as an electric vehicle, electric bus, electric boat (Automated Guided Vehicle, AGV), power tool, drone, spacecraft (including airplanes, rockets, spacecraft, etc.), etc. In other embodiments, the power device 10 may also be a mobile phone, tablet, laptop, electric toy, electric vehicle, etc.

[0035] The number of battery systems 102 in the power-consuming device 10 provided in this embodiment can be designed as needed, and is not limited to a fixed number. Figure 1 The example shown is a limitation.

[0036] Figure 2 This is a schematic structural diagram of a battery system according to an embodiment of the present disclosure. Figure 2 The battery system 20 in the middle can provide Figure 1 Battery system 102 in the middle. For example... Figure 2 As shown, the battery system 20 may include a battery pack 202 and a controller 204 coupled to the battery pack 202. The controller 204 may be connected to the battery pack 202 in a wired or wireless manner.

[0037] The battery pack 202 may include a first housing 2022 and a battery module 2024. The first housing 2022 is filled with a first fluid medium 2026, and the battery module 2024 is at least partially immersed in the first fluid medium 2026.

[0038] In some embodiments, the first fluid medium 2026 may be a liquid, such as an insulating liquid with good heat dissipation properties, which can improve the temperature control effect on the battery module 2024.

[0039] In some embodiments, the first fluid medium 2026 may be one or more of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, fluorinated liquid, etc. In some examples, the fluorinated liquid may include at least one of ethyl nonafluorobutyl ether, perfluorohexane, etc. Hydrocarbon synthetic oil may include at least one of polyalphaolefin, alkylbenzene, polybutene, etc. Ester synthetic oil may include at least one of polyol ester, diester, etc. It should be understood here that the fluid medium described in this disclosure is not limited to the examples above, and may also include other dielectric liquids known in the art or developed hereafter that have the required electrical insulation and chemical stability and are compatible with the module housing and battery assembly, such as other saturated or unsaturated hydrocarbons (e.g., C14-C50 alkanes, alkenes), aromatics (e.g., dialkylbenzene, cyclohexylbenzene), esters, ethers, ketones, halogenated hydrocarbons (e.g., hydrofluoroethers), or any combination thereof.

[0040] In some embodiments, the capacity of the first fluid medium filling the inner cavity of the first housing can be designed based on factors such as the cooling / heating capacity of the first fluid medium actually selected and the energy release of the battery.

[0041] The battery module 2024 may include a second housing 20242 and a battery cell 20244. The second housing 20242 is filled with a second fluid medium 20246, and the battery cell 20244 is at least partially immersed in the second fluid medium 20246.

[0042] In some embodiments, the second fluid medium can be a liquid, such as an insulating liquid with good thermal conductivity, which can improve the temperature control effect on the battery cell 20244.

[0043] In some embodiments, the second fluid medium may be one or more of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, fluorinated liquid, etc.

[0044] In some embodiments, the first fluid medium and the second fluid medium may have the same composition. By designing that the first fluid medium and the second fluid medium have the same composition, the possibility that the mixing process of the first fluid medium and the second fluid medium will affect the state of the fluid medium when controlling the flow of the first fluid medium into the second housing or the flow of the second fluid medium out of the second housing into the first housing can be effectively reduced, thereby improving the stability of the battery system.

[0045] For example, both the first fluid medium and the second fluid medium can be silicone oil.

[0046] For example, the first fluid medium and the second fluid medium may both be composed of the same two substances (exemplarily, silicone oil and ethyl nonafluorobutyl ether), and the relative contents of the two substances may be the same or different.

[0047] In other embodiments, the components of the first fluid medium and the second fluid medium may be different. For example, the first fluid medium may be one of silicone oil, mineral oil, ethyl nonafluorobutyl ether, and perfluorohexane, and the second fluid medium may be another of silicone oil, mineral oil, ethyl nonafluorobutyl ether, and perfluorohexane.

[0048] In some embodiments, a battery cell is the smallest physical unit that directly converts chemical energy into electrical energy, and is also the most basic "energy container" in a battery system. A battery cell includes a positive electrode, a negative electrode, and an electrolyte layer. During the charging and discharging process of a battery cell, active ions (e.g., lithium ions, sodium ions, etc.) repeatedly insert and extract between the positive and negative electrodes. The electrolyte layer (or a separator layer impregnated with electrolyte) is disposed between the positive and negative electrodes, not only preventing short circuits between the positive and negative electrodes but also allowing active ions to pass through.

[0049] The electrolyte of the battery cell in the battery system provided in this disclosure can be a liquid electrolyte, a liquid-solid hybrid electrolyte, an all-solid electrolyte, etc., and this disclosure does not impose any limitations.

[0050] In some embodiments, the shape of the battery cell may be cylindrical, flat, or polygonal. The battery cell may be a rigid-cased battery cell (e.g., cylindrical battery, prismatic battery), a pouch battery cell, etc. This disclosure is not limited in this respect.

[0051] In some embodiments, battery cells may release harmful substances under certain circumstances, and the first fluid medium and / or the second fluid medium may include additives capable of neutralizing the harmful substances generated by the battery cells.

[0052] For example, batteries whose electrolytes include sulfides may release sulfur-containing toxic substances under certain circumstances, especially in the case of thermal runaway, which may release large amounts of sulfur-containing toxic fumes such as hydrogen sulfide, sulfur dioxide, sulfur vapor, etc. In such cases, at least one of the following substances can be added to the first fluid medium and / or the second fluid medium: diisooctyl monoethanolamine, zinc isooctanoate, amino-modified perfluoropolyether, chloride, sulfate, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, alkaline inorganic substances, etc., to neutralize and render harmless the sulfur-containing toxic fumes, thereby reducing the impact on the surrounding environment.

[0053] In some examples, chlorides may include ferric chloride, etc. Sulfates may include ferric sulfate, etc. Alkaline inorganic substances may include at least one of, for example, hydroxides, oxides, carbonates, or bicarbonates of alkali metals or alkaline earth metals. Specifically, hydroxides in alkaline inorganic substances may include at least one of, for example, sodium hydroxide, potassium hydroxide, calcium hydroxide, magnesium hydroxide, lithium hydroxide, etc.; oxides may include at least one of, for example, calcium oxide, magnesium oxide, sodium oxide, etc.; and carbonates may include at least one of, for example, sodium carbonate, potassium carbonate, calcium carbonate, etc. It should be understood that the additives disclosed herein are not limited to the examples above, and may also include other substances known in the art or developed hereafter that can achieve the same or similar harmless treatment functions.

[0054] The controller 204 can be used to control the flow of a second fluid medium 20246 from the second housing 20242 into the first housing 2022, or to control the flow of a first fluid medium 2026 from the first housing 2022 into the second housing 20242, so that at least a first surface (20244a, or 20244b) of the battery cell 20244 is subjected to a given pressure. The given pressure can be the pressure required by the battery cell.

[0055] In some embodiments, for all-solid-state batteries, the required pressure refers to the external pressure that needs to be applied to maintain good solid-solid interface contact between the solid electrolyte and the electrode. It can be tens to hundreds of megapascals (MPa), or as low as 5 MPa or even around 0.5 MPa or 0.1 MPa, as long as it meets the requirements for the operation of the solid-state battery.

[0056] In other embodiments, for liquid batteries, the required pressure may refer to, for example, the external pressure required to suppress lithium dendrite growth, optimize lithium metal deposition morphology, improve cycle stability, etc.

[0057] In other embodiments, for semi-solid batteries, the required pressure may refer, for example, the constraint pressure applied to ensure a certain interface contact and reduce the effects of electrode expansion and contraction while taking into account the performance of the solid-liquid mixed electrolyte system.

[0058] For example, during the operation of the battery system 20, the battery cell 20244 may undergo some deformation. When the second housing 20242 is in a sealed state, the pressure on the first surface (20244a, or 20244b) of the battery cell 20244 may differ from the required pressure. The controller 204 can control the flow of the second fluid medium 20246 from the second housing 20242 into the first housing 2022 according to a given pressure, or control the flow of the first fluid medium 2026 from the first housing 2022 into the second housing 20242, so that the first surface (20244a, or 20244b) of the battery cell 20244 can withstand the required pressure.

[0059] According to the battery system provided in the embodiments of this disclosure, the controller in the battery system can control the flow of the second fluid medium immersing the battery cell in the second housing of the battery module into the first housing covering the battery module, or control the flow of the first fluid medium in the first housing into the second housing, based on the pressure required to be borne by the first surface of the battery cell (and the actual pressure changes it experiences). This allows the second fluid medium in the second housing to provide the first surface of the battery cell with the given pressure it needs to bear, while the first fluid medium in the first housing can be used to dissipate heat and / or keep the battery cell warm, thereby achieving thermal management of the battery cell and suppression of thermal runaway propagation. Furthermore, the second fluid medium can provide a uniform, stable, and easily precisely controlled given pressure to the first surface of the battery cell, while the first fluid medium can be set to a state that is more conducive to heat dissipation and / or heat preservation (e.g., circulating at a certain speed without considering the instantaneous pressure stability of the battery cell surface), thereby achieving more refined thermal management, pressure management, and more effective suppression of thermal runaway propagation.

[0060] In some embodiments, the battery system may further include a circulation device for controlling the flow of a first fluid medium in a circulation path, the circulation path including the inner cavity of the first housing, thereby circulating the first fluid medium within the first housing. For example, circulation facilitates rapid control of the temperature of the first fluid medium within the first housing, which can improve the heat exchange rate between the first fluid medium and the battery module, thereby rapidly controlling the temperature of the battery cells within a preset optimal operating temperature range. Heat transfer between the first fluid medium and the second fluid medium can be achieved either through the second housing itself (e.g., by designing the second housing as a material with good thermal conductivity, such as metal), or through fluid flow between the first and second housings (e.g., the second fluid medium immersing the battery cells in the second housing of the battery module flows into the first housing, or the first fluid medium in the first housing flows into the second housing).

[0061] In some embodiments, when the battery cell is a battery in which the electrolyte includes a sulfide, the optimal operating temperature range can be between -40°C and 160°C, preferably between -20°C and 100°C; a typical example could be 80°C. 5℃.

[0062] Figure 3 A schematic diagram of a battery system including a cycling device is shown according to an exemplary embodiment. Figure 3 As shown, the battery system 30 may include a controller 302, a battery pack 304, a fluid medium storage device 306, an inlet control valve 308, an outlet control valve 310, and a circulation device 312. The controller 302 is connected to the battery pack 304, the inlet control valve 308, the outlet control valve 310, and the circulation device 312 via wired or wireless means, respectively. The fluid medium storage device 306 is coupled to the circulation device 312. The inlet control valve 308 and the outlet control valve 310 can be respectively connected to the first housing of the battery pack 304. Figure 3 (not shown in the image) coupling. Figure 3 The controller 302 and battery pack 304 in the middle can be correspondingly... Figure 2 Examples of controller 204 and battery pack 202 in the example.

[0063] In some embodiments, the circulation device 312 may be a circulation pump. Fluid medium in the fluid medium storage device 306 flows into the circulation pump, which provides power to make the fluid medium flow in the circulation path. Figure 3 For example, the circulation path may include the pipeline between the circulation device 312 and the inlet control valve 308, the pipeline between the inlet control valve 308 and the battery pack 304, the inner cavity of the first housing of the battery pack 304, the pipeline between the battery pack 304 and the outlet control valve 310, the pipeline between the outlet control valve 310 and the fluid medium storage device 306, etc.

[0064] The controller 302 can be used to control the inlet control valve 308 according to the state parameters of the first fluid medium and / or the second fluid medium in the battery pack 304, so as to control the fluid medium drawn from the fluid medium storage device 306 by the circulation device 312 to flow into the first housing of the battery pack 304 through the inlet control valve 308.

[0065] The controller 302 can also be used to control the outlet control valve 310 according to the state parameters of the first fluid medium and / or the second fluid medium, so as to control the first fluid medium in the first housing of the battery pack 304 to flow back to the fluid medium storage device 306 through the outlet control valve 310.

[0066] In some embodiments, the state parameters may include at least one of pressure, stress, temperature, and flow rate.

[0067] For example, controller 302 can be activated by a sensor ( Figure 3 Not shown in the text, for example, you can refer to Figure 5 The sensor 508 in the first housing detects the temperature of the first fluid medium and controls the opening or closing of the inlet control valve 308 and / or the outlet control valve 310 accordingly, thereby increasing or decreasing the total amount of the first fluid medium in the first housing.

[0068] For example, controller 302 can be activated via a sensor ( Figure 3 Not shown in the text, for example, you can refer to Figure 5 The sensor 508 detects the flow rate of the first fluid medium and controls the opening degree of the inlet control valve 308 and / or the outlet control valve 310 accordingly, as well as the rotational speed of the pump shaft of the circulation device 312, thereby increasing or decreasing the flow rate of the first fluid medium in the circulation loop.

[0069] For example, controller 302 can be coupled to (e.g., in) Figure 6 The sensor on switch 6062b detects the pressure of the second fluid medium and controls the first fluid medium to flow into the second housing, or controls the second fluid medium to flow out of the second housing and into the first housing. Then, controller 302 can control the pressure of the second fluid medium through the sensor ( Figure 3 Not shown in the text, for example, you can refer to Figure 5 The sensor 508 detects changes in the pressure, temperature, flow rate, and other state parameters of the first fluid medium. When the changes are large, the sensor 508 controls the inlet control valve 308 and / or the outlet control valve 310 to adjust the state parameters of the first fluid medium.

[0070] A single battery cell is often insufficient to meet the power and range requirements of large loads, so multiple battery cells are typically connected in series or parallel to form a battery system. In a battery system comprising multiple battery cells, if one cell experiences thermal runaway, it can cause rapid propagation throughout the entire system, accompanied by the release of large amounts of toxic gases. Under thermal runaway conditions, the first and second fluid media in the battery system of this disclosure can be used not only as coolants / heating fluids but also as thermal runaway protection media. When a battery cell experiences thermal runaway, the heat, ejected material, and high-temperature gases released by the battery first come into contact with the surrounding second fluid media. The second fluid media absorbs some of the transient heat through its heat capacity and / or phase change enthalpy, and the heat is carried away from the runaway area by the forced circulation of the first fluid media, reducing the heating rate of other battery cells and thus slowing down or preventing the spread of thermal runaway.

[0071] Figure 4 A schematic diagram of the first housing of a battery pack is shown according to an exemplary embodiment. Figure 4 The first housing 40 shown can be Figure 2 An exemplary embodiment of the first housing 2022 in the example can be applied, for example, to... Figure 3 Battery pack 302 in battery system 30.

[0072] like Figure 4 As shown, the first housing 40 of the battery pack may include a top cover 402 and a first housing wall 402. The top cover 402 may have an inlet control valve mounting hole 4022 and an electrical connection passage 4024. The first housing wall 402 may have an outlet control valve mounting hole 4042 at its bottom. Exemplarily, the inlet control valve mounting hole 4022 and the outlet control valve mounting hole 4042 can be correspondingly installed... Figure 3 The diagram shows the inlet control valve 308 and the outlet control valve 310.

[0073] In some embodiments, the internal space of the first housing of the battery pack can be divided into a battery compartment and an electrical component compartment, the battery compartment and the electrical component compartment are sealed and isolated, the battery module is located in the battery compartment, the electrode terminals of the battery pack can be located in the electrical component compartment, and the electrode terminals of the battery pack are electrically connected to the tabs of the battery cells.

[0074] Still with Figure 4 For example, a partition 406 may be provided in the first housing 40, which can divide the internal space of the first housing 40 of the battery pack into a battery compartment 4002 and an electrical component compartment 4004.

[0075] Figure 5 according to Figure 3 and Figure 4 An exemplary cross-sectional view of a battery pack is shown. Figure 5 The battery pack 50 in the example uses Figure 4 The first shell 40 in the middle. Figure 5 Zhongyu Figure 3 and Figure 4 The same labels in the text indicate the same structure.

[0076] Reference Figure 4 and Figure 5 The battery module 502 is located in the battery compartment 4002, which is at least partially filled with the first fluid medium 504. An inlet control valve mounting hole 4022 and an outlet control valve mounting hole 4044 are correspondingly provided on the upper cover 402 and the first housing wall 402 surrounding the battery compartment 4002, respectively. An inlet control valve 308 and an outlet control valve 310 can be respectively installed in the inlet control valve mounting hole 4022 and the outlet control valve mounting hole 4044.

[0077] In some embodiments, the number of inlet control valves 308 and outlet control valves 310 can be designed based on factors such as the size and number of battery modules 502 (one or more battery modules can be installed in the battery pack). For example, the number of inlet control valves 308 and outlet control valves 310 can both be three times the number of battery modules 502, that is, three inlet control valves 308 and three outlet control valves 310 correspond to one battery module 502, and are respectively located at ( ) of the battery module 502. Figure 5 (Directly above and below in the Y direction); the multiplier can also be one, two, four, five or more.

[0078] It is understood that the number of inlet control valve mounting holes 4022 and outlet control valve mounting holes 4044 should be consistent with the number of inlet control valves 308 and outlet control valves 310, respectively, and can be evenly distributed along the length of the battery module 502 (e.g., Figure 5 (in the X direction).

[0079] Continue to refer to Figure 5 The electrode terminals 506 of the battery pack can be located in the electrical component compartment 4004, and the electrode terminals 506 of the battery pack are electrically connected to the tabs (5022a, 5022b) of the individual battery cells. A module aggregation passage 4062 can be provided on the separator 406, and the connection lines between the electrode terminals 506 and the tabs (5022a, 5022b) of the individual battery cells can be arranged through the module aggregation passage 4062.

[0080] By designing isolated battery compartments and electrical component compartments within the first housing of the battery pack, it is possible to fill only the battery compartment with the first fluid medium. The battery pack's electrode terminals can remain in the electrical component compartment without being immersed in the fluid medium, thereby reducing the risk of leakage through the fluid medium and improving the safety of the battery system. Even if the fluid medium is an insulator, immersion may still cause unnecessary corrosion to the electrical components, making this isolation necessary.

[0081] Continue to refer to Figure 4 and Figure 5 A sensor mounting hole 4064 can be provided on the partition 406, and the sensor 508 can be installed in the sensor mounting hole 4064. The sensor 508 can be wirelessly connected to the controller outside the battery pack. Figure 4 and Figure 5 (Not shown in the image) to feed back the detected status parameter data to the controller. The module aggregation passage 4062 and sensor mounting hole 4064 on the partition 406 need to be sealed to prevent the first fluid medium from flowing into the electrical component compartment 4004.

[0082] The top cover 402 may also have an electrical connection passage 4024, which is located in the electrical component compartment 4004. Figure 5 Above (in the Y direction), the electrical connection path 4024 can be used to bring the electrical wiring of the battery pack (leading out from the electrode terminal 506) outside the battery pack, for example, it can be the only route to the external environment.

[0083] In some embodiments, the battery system may include multiple battery packs, and the top cover of the first housing of the multiple battery packs may be integrally formed. In this case, the number of electrical connection passages on the top cover may be the same as the number of battery packs.

[0084] In some embodiments, the battery pack may further include a battery mounting bracket, through which the battery module is secured in the battery compartment.

[0085] Continue to refer to Figure 5 The battery module mounting bracket 510 can be installed at the bottom of the battery compartment 4002, and the battery module 502 is installed in the battery compartment 4002 through the battery mounting bracket 510.

[0086] In some embodiments, the given pressure required for a single battery cell may be equal to or slightly below atmospheric pressure.

[0087] In other embodiments, the required pressure for a single battery cell is higher than atmospheric pressure. For example, it can be in the range of 1–20 MPa, preferably 5–15 MPa, more preferably 8–12 MPa; a typical example could be 10 MPa. For the aforementioned semi-solid or all-solid electrolyte battery cells, a pressure higher than atmospheric pressure may be required to constrain the battery electrode stack, the solid electrolyte interface, and the outer surface of the cell casing. This pressure, higher than atmospheric pressure, also inhibits the entry of air and moisture into the battery system, reducing the risk of harmful gases being generated from contact between the solid electrolyte, especially sulfide solid electrolytes, and moisture.

[0088] In some embodiments, the pressure exerted by the first fluid medium in the first housing on the battery module may be less than or equal to the pressure exerted by the second fluid medium in the second housing on the individual battery cells. Maintaining the first fluid medium at a reduced pressure simplifies the operation of the temperature control system. Especially when the second fluid medium needs to exert higher pressure on the individual battery cells, reducing the pressure of the first fluid medium allows the entire temperature control system to avoid operating in a high-pressure system, improving safety and reducing equipment maintenance costs.

[0089] For battery cells including or including only solid electrolytes, the battery system provided in this disclosure uses a (incompressible) first fluid medium and a second fluid medium as a fully encapsulated (liquid) functional medium. The first fluid medium forms a continuous, uniform, and flowable pressure field and heat transfer field on the outer surface of the battery module, and the second fluid medium applies uniform hydrostatic pressure to at least the first surface of the battery cell within a sealed second housing. This can form uniform constraints on the battery electrode stack, solid electrolyte interface, and specific outer surfaces of the cell housing without introducing a rigid local compression structure. This helps to reduce the performance degradation and safety risks caused by volume changes, interface debonding, local bulging, or uneven stacking pressure during the charging and discharging process of solid batteries. Furthermore, by controlling the flow of the first fluid medium in the circulation path of the cavity including the first housing, the heat dissipation performance of the first fluid medium in the first housing is improved.

[0090] Compared to air cooling, liquid plate cooling, or atmospheric pressure immersion cooling methods used in related technologies, the battery system provided in this disclosure has a first immersion medium in direct contact with the outer surface of the battery module, and a second immersion medium in direct contact with at least the first surface of the battery cell. This effectively eliminates the problems of interfacial thermal resistance, local hot spots, and uneven temperature distribution that exist in cold plate cooling. The second immersion medium in the battery module can absorb Joule heat, polarization heat, and side reaction heat generated during the charging and discharging process of the battery, and can release these heats through a heat exchanger to the cooling circuit filled with the first immersion medium outside the battery module. This achieves temperature uniformity inside the battery module, reduces the temperature difference between batteries, and improves the thermal management efficiency and lifespan consistency of the battery system. Similar scenarios require heating of individual battery cells.

[0091] In some embodiments, the first fluid medium in the first housing can be a normal pressure fluid, which can effectively reduce the risk of battery pack damage under pressure and improve the stability of the battery system.

[0092] Still with Figure 5 For example, the first fluid medium 504 in the battery compartment 4002 does not require additional pressure to be applied inside the battery compartment 4002, and can be controlled according to the controller ( Figure 5The output result (not shown) is fed into the battery module 502 by the controller. Alternatively, the controller can also control the second fluid medium (not shown) inside the battery module 502 based on the output result. Figure 5 (Not shown in the image) flows out to battery compartment 4002.

[0093] Figure 6 A cross-sectional schematic diagram of a battery module is shown according to an exemplary embodiment. Figure 6 The battery module 60 in the middle can be Figure 2 Example of a 2024 battery module. (e.g.) Figure 6 As shown, the battery cell 604 in the second housing 601 of the battery module 60 is immersed in the second fluid medium 604, which is the surface of the battery cell 604 that intersects (e.g., can be perpendicular) the X direction. Figure 6 The first surface 6022a, the second surface 6022b, etc. provide the required pressure.

[0094] The second fluid medium gap placed between adjacent battery cells can act as a liquid thermal buffer layer, increasing the thermal resistance and thermal capacity path for heat propagation from the runaway battery to adjacent batteries, thereby delaying or blocking the heat spread process. The second fluid medium can also be used in conjunction with other thermal insulation materials such as silicone pads and nano-pads to enhance thermal insulation capabilities.

[0095] In some embodiments, refer to Figure 6 The battery cell 604 may include a tab 6024 disposed on a first side 6026, the first side 6026 intersecting (e.g., perpendicular to) a first surface 6022a, the first side 6026 as shown in the figure. Figure 6 The center point intersects or is perpendicular to the Z direction. The tab 6024 is not immersed in the second fluid medium 604.

[0096] In some embodiments, the tab 6024 may be at least partially located in an opening at a corresponding position in the second housing 601, and the gap between the tab 6024 and the opening may be sealed by a sealing material such as sealant. In embodiments where a portion of the tab 6024 is located in an opening at a corresponding position in the second housing 601, another portion of the tab 6024 may extend outside the second housing 601.

[0097] By setting the tabs of the battery cell to be not immersed in a second fluid medium, the tabs can avoid being subjected to pressures exceeding atmospheric pressure, even when the second fluid medium provides a pressure higher than atmospheric pressure to the first surface of the battery cell.

[0098] In some embodiments, the tab is immersed in a first fluid medium.

[0099] By setting the tabs of the battery cells to be immersed in the first fluid medium instead of the second fluid medium inside the battery module, unnecessary damage to the tabs can be avoided by subjecting them to pressures exceeding atmospheric pressure. At the same time, the first fluid medium is used to dissipate heat from the tabs.

[0100] In some embodiments, the second housing may include a plurality of cavities for containing a second fluid medium, and the battery cell includes a first surface and a second surface opposite to each other, wherein the pressure inside the cavity where the first surface is located and the cavity where the second surface is located can vary independently from each other.

[0101] Continue to refer to Figure 6 ,by Figure 6 The first surface 6022a and the second surface 6022b of a battery cell 602, as indicated in the diagram, are not connected when the second housing 601 is sealed. This allows the controller to independently control the pressure on the first surface 6022a and the second surface 6022b by separately controlling the fluid medium flowing into and out of these cavities. This enables precise control of the pressure on each surface of the battery. Furthermore, since each cavity involves only a small number of battery cells (e.g., only the two surfaces of two adjacent battery cells), the controller can quickly adjust the pressure within the cavity in response to pressure changes caused by the expansion and contraction of the battery cells, ensuring that the battery cell surface always bears the required given pressure.

[0102] Continue to refer to Figure 6 A switch mounting hole 6012 can be opened on the top of the second battery housing 601 corresponding to the cavity where the first surface 6022a of each battery cell 602 is located, and the switch 6062 can be installed in the switch mounting hole 6012.

[0103] In some embodiments, the battery module may be equipped with multiple sensors that can detect state parameters of the second fluid medium. Each sensor may be wirelessly connected to a controller, allowing the controller to control the opening or closing of a switch based on the state parameters of the second fluid medium measured by the sensors. For example, the sensors of the battery module may be coupled to a switch.

[0104] For example, switch 6062a can be used by a controller ( Figure 6 (Not shown) can be individually controlled to open or close, allowing the first fluid medium outside the battery module 60 ( Figure 6 (Not shown) flows into the cavity where the first surface 6022a is located, or causes the second fluid medium 604a in the cavity where the first surface 6022a is located to flow out of the battery module 60.

[0105] For example, switch 6062b can be used by a controller ( Figure 6 (Not shown) can be individually controlled to open or close, allowing the first fluid medium outside the battery module 60 ( Figure 6 (Not shown) flows into the cavity where the first surface 6022b is located, or causes the second fluid medium 604b in the cavity where the first surface 6022b is located to flow out of the battery module 60.

[0106] Switch 6062b in Figure 6 The position shown is for illustrative purposes only. In some embodiments, switch 6062b may be set to... Figure 6 From the perspective of the second housing 601, the bottom, and / or top, and / or sides, etc., through the bottom inlet, top outlet, or side inlet / side outlet flow channel design, allow low-temperature fluid media such as silicone oil to preferentially enter the gap area between adjacent battery cells, achieving multi-surface heat exchange, reducing local hot spots in the battery and temperature differences within the module, improving thermal management capabilities under high-rate operation conditions, and alleviating the rate-rate temperature rise problem caused by high battery internal resistance. This issue is particularly important for all-solid-state batteries.

[0107] The basic principles of this disclosure have been described above with reference to specific embodiments. It should be noted that the advantages, benefits, and effects mentioned in the embodiments of this disclosure are merely examples and not limitations, and should not be considered as essential features of each embodiment of this disclosure. Furthermore, the specific details disclosed above are for illustrative and facilitative purposes only, and are not limitations; these details do not limit the scope of this disclosure to the necessity of employing the aforementioned specific details. It should also be noted that in the apparatus and methods of this disclosure, the components or steps can be decomposed and / or recombined. These decompositions and / or recombinations should be considered equivalent solutions of this disclosure.

[0108] Furthermore, words such as “including,” “contains,” and “has” are open-ended terms meaning “including but not limited to,” and are used interchangeably with them. The words “or” and “and” as used here refer to the words “and / or,” and are used interchangeably with them unless the context explicitly indicates otherwise. The word “such as” as used here refers to the phrase “such as but not limited to,” and is used interchangeably with it.

[0109] The above description of the disclosed aspects is provided to enable any person skilled in the art to make or use this disclosure. Various modifications to these aspects will be readily apparent to those skilled in the art, and the general principles defined herein can be applied to other aspects without departing from the scope of this disclosure. Therefore, this disclosure is not intended to be limited to the aspects shown herein, but rather to be carried out within the widest scope consistent with the principles and novel features disclosed herein.

Claims

1. A battery system comprising a battery pack and a controller coupled to the battery pack, wherein: The battery pack includes a first housing and a battery module, wherein the first housing is filled with a first fluid medium, and the battery module is at least partially immersed in the first fluid medium. The battery module includes a second housing and a battery cell, wherein the second housing is filled with a second fluid medium, and the battery cell is at least partially immersed in the second fluid medium; The controller is used to cause at least a first surface of the battery cell to be subjected to a given pressure by controlling the flow of a second fluid medium in the second housing into the first housing, or by controlling the flow of a first fluid medium in the first housing into the second housing.

2. The battery system according to claim 1 further includes a circulation device, the circulation device being used to control the flow of the first fluid medium in a circulation path, the circulation path including the inner cavity of the first housing, so as to keep the temperature of the battery cell within a preset temperature range.

3. The battery system according to claim 1, wherein, The pressure exerted by the first fluid medium in the first housing on the battery module is less than or equal to the pressure exerted by the second fluid medium in the second housing on the battery cell.

4. The battery system according to claim 1, wherein, The given pressure is higher than atmospheric pressure.

5. The battery system according to claim 3, wherein, The first fluid medium in the first housing is a normal pressure fluid.

6. The battery system according to any one of claims 3 to 5, wherein, The battery cell includes a tab disposed on a first side, the first side intersecting the first surface, and the tab is not immersed in a second fluid medium.

7. The battery system according to claim 6, wherein, The electrode is immersed in the first fluid medium.

8. The battery system according to any one of claims 1 to 5, wherein, The first fluid medium and the second fluid medium have the same composition.

9. The battery system of claim 2, further comprising a fluid medium storage device coupled to the circulation device, an inlet control valve and an outlet control valve coupled to the controller and the first housing of the battery pack, wherein, The controller is also configured to control the inlet control valve according to the state parameters of the first fluid medium and / or the second fluid medium, so as to control the fluid medium drawn from the fluid medium storage device by the circulation device to flow into the first housing through the inlet control valve; The controller is also configured to control the outlet control valve according to the state parameters of the first fluid medium and / or the second fluid medium, so as to control the first fluid medium in the first housing to flow back to the fluid medium storage device through the outlet control valve.

10. The battery system according to claim 9, wherein, The state parameters include at least one of pressure, stress, temperature, and flow rate.

11. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, The internal space of the battery pack is divided into a battery compartment and an electrical component compartment. The battery compartment and the electrical component compartment are sealed and isolated. The battery module is located in the battery compartment, and the electrode terminals of the battery pack are located in the electrical component compartment. The electrode terminals of the battery pack are electrically connected to the tabs of the individual battery cells.

12. The battery system according to claim 11, wherein, The battery pack also includes a battery mounting bracket, through which the battery module is fixed in the battery compartment.

13. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, The second housing includes multiple cavities for containing a second fluid medium. The battery cell includes opposing first and second surfaces. The pressure inside the cavity where the first surface is located and the cavity where the second surface is located can change independently of each other.

14. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, The first fluid medium and / or the second fluid medium include additives capable of neutralizing harmful substances generated by battery cells.

15. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, The additive is selected from at least one of diisooctyl monoethanolamine, zinc isooctanoate, amino-modified perfluoropolyether, 1-butyl-3-methylimidazolium hexafluorophosphate, 1-ethyl-3-methylimidazolium bis(trifluoromethanesulfonyl)imide, chloride, sulfate, and basic inorganic substances.

16. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, The first fluid medium and the second fluid medium are one or more of silicone oil, mineral oil, hydrocarbon synthetic oil, ester synthetic oil, and fluorinated liquid.

17. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, Both the first fluid medium and the second fluid medium are liquids.

18. The battery system according to any one of claims 1 to 5, 9, and 10, wherein, The battery cell includes a solid electrolyte.

19. The battery system according to claim 18, wherein, The electrolyte in each battery cell is a solid electrolyte.

20. An electrical device, characterized in that, Includes the battery system according to claims 1-19, the battery system being used to provide electrical energy.

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