High-voltage battery and battery housing

Abstract

The invention relates to a high-voltage battery (10), in particular for use in a hybrid vehicle, having a battery housing (70), wherein the battery housing (70) encloses an interior space with battery cells arranged therein, characterized in that the battery housing (70) is designed in two parts with a first receiving space (73) for receiving the battery cells and a second receiving space (74) for receiving safety devices for a plurality of secondary power paths (82), wherein a partition wall (75) is arranged between the first receiving space (73) and the second receiving space (74), wherein the partition wall (74) has at least one recess (77) for the passage of at least one main power path (80, 87) for contacting the battery cells, and wherein the secondary power paths (82) branch off from at least one main power path (80) for supplying electricity to various secondary consumers of a vehicle.

Description

A lithium ion battery for a battery electric vehicle (BEV) is a rechargeable battery that uses lithium ions as a main carrier of electric charge. These batteries are the most important component of a BEV because they are the energy source for driving the vehicle. A lithium ion battery for BEVs is comprised of several important components. The battery cells are the basic components of a lithium-ion battery. Each cell consists of an anode, a cathode, an electrolyte and a separator. A plurality of cells are connected to form a module. The modules are designed to provide a certain voltage and capacitance and are often protected in a housing. A battery pack is comprised of multiple modules arranged in a particular configuration to achieve the desired total voltage and capacity. The battery pack is housed in a robust housing that provides mechanical protection and thermal control.The basic functioning of a lithium ion battery is based on the flow of lithium ions between anode and cathode through the electrolyte. During operation of the vehicle, lithium ions flow through the electrolyte from the anode to the cathode. This flow generates a current that flows through an external circuit and drives the drive motor of the vehicle. When the battery is charged, electric current is conducted into the battery, whereby lithium ions flow in the reverse direction from the cathode to the anode. This process stores electrical energy in the battery by "storing" lithium ions in the anode.However, lithium ion batteries may become dangerous in improper handling or overheating, therefore, a cooling system is for cooling the battery to maintain it in the optimum temperature range and avoid overheating. Heating can also be provided in order to prevent cold sensitivity. Furthermore, fuses and contactors are provided in order to protect the battery from short-circuiting. In this case, the battery management system (BMS) continuously monitors the state of the battery in order to minimize risks and ensure safety.The main difference between a lithium ion battery for a pure electric vehicle (BEV) and a hybrid electric vehicle (HEV) is in its function, size, capacity and purpose they fulfill in the respective propulsion system. In a BEV, the lithium ion battery is the only energy source for powering the vehicle. It powers the electric motor, which drives the vehicle. Therefore, the battery must be large enough to ensure sufficient range and support all functions of the vehicle. In a hybrid vehicle, the lithium ion battery operates in combination with an internal combustion engine. The battery typically serves to assist the internal combustion engine or to drive purely electrically in certain situations (e.g., at low speeds or on short distances). Since the engine is the main power source, the battery may be smaller and have a smaller capacity.The term "hybrid vehicle" refers to vehicles that use two or more sources of power for propulsion, typically a combination of an internal combustion engine and one or more electric motors. This technology is used in various vehicle categories, including passenger cars and trucks. Hybrid technologies are increasingly used in trucks in applications where higher fuel efficiency or lower emissions are required. Hybrid trucks use similar concepts to hybrid cars, but with larger and more powerful components to meet the higher demands.The lithium ion battery in a BEV is typically substantially larger and has a higher capacity because it must propel the entire vehicle. These batteries may store hundreds of kilowatts hours (kWh) of energy to ensure sufficient range. On the other hand, the lithium ion battery in an HEV is normally smaller and has a smaller capacity because it has only a supporting function. These batteries typically have a capacity of several kilowatts hours to about 10-20 kWh. Since BEVs are operated purely electrically, they rely on a charging infrastructure. The batteries must be regularly charged at charging stations or at home. The charging times are longer as the batteries are larger. Hybrid vehicles typically do not require a special charging infrastructure, as the internal combustion engine can charge the battery during travel (by recuperation or directly by the engine). This makes HEVs more flexible with respect to fuel sources and charging times.Both lithium-ion batteries for electric vehicles (EVs) and for hybrid vehicles (HEVs) are high-voltage batteries. In pure electric vehicles, high-voltage batteries are typically used in the voltage range from 300 to 800 volts. This higher voltage is required to provide sufficient energy for the operation of the electric motor, the supply of the electrical systems, and a sufficient range. Some high power electric vehicles use voltages in the upper range or even higher to achieve higher powers. Hybrid vehicles and plug-in hybrid vehicles (PHEVs) often operate at slightly lower voltages, typically in the range of 200 to 400 volts. This is because in hybrid vehicles, the internal combustion engine plays the main role and the battery is mainly used for assisting electric drive or for short electric travel.Due to the high voltages in these batteries, special safety measures are required to minimize the risk of electric shocks, short circuits or other hazards.The battery management system (BMS) is thus a central element for the operation and safety of lithium-ion vehicle batteries. It monitors the voltage, current and temperature of the cells and modules, controls the charging and discharging process, and protects the battery from overheating or overcharging. The BMS consists of various components. Contactors are electrical switches that can control the current flow and interrupt it if necessary. Contactors are important for safety because they can interrupt current flow when problems occur. Fuses protect the battery from overloading and short-circuiting. In the event of a fault, the fuse melts and interrupts the current flow in order to avoid damage. Gauges measure the voltage, current and temperature of the battery to ensure that it is operating in the safe area.The batteries of BEVs require larger and more complex BMS systems because they are operated purely electrically, while BMS systems in smaller lithium-ion vehicle batteries used in hybrid propulsion concepts are typically less complex and smaller. Because hybrid batteries often support only the engine and thus require fewer contactors and fuses. Hybrid batteries also generally have only one terminal for the current flow, since they are used only occasionally for energy consumption and output.However, it may be useful to also equip a hybrid battery with a plurality of power paths, in order to operate, for example, electrical auxiliary consumers such as an electrical air conditioning compressor. However, each of these power paths must be equipped with a separate electrical fuse to ensure safety. The fuses could be housed in a separate fuse box, but that requires space in the vehicle and additional components, thereby increasing cost and complexity. Moreover, the installation of a separate fuse box requires additional working steps during the vehicle installation. Since the batteries are high-voltage batteries, special safety measures and trained personnel are also required in order to ensure safety.DE 10 2016 105 196 A1 discloses a bearing arrangement for securing a battery arrangement, having a base body which has a receptacle for the securing means, a plurality of electrical connections which are formed on the base body in order to connect the securing means to electrical battery module connections of the battery arrangement, wherein the base body has a plurality of connection points in order to fix the bearing arrangement in a battery housing of the battery arrangement.US 2024 / 0 154 236 A1 discloses an electric vehicle having an electric motor that generates a rotational force that drives a drive wheel, and a battery housing that defines a battery compartment in which at least one battery is accommodated. In the battery compartment are terminals electrically connected to the corresponding terminals of the battery. The electrical energy of the battery is transmitted to the electric motor via power lines. The power lines include a connection circuit having a connection portion in which the power lines extending from the terminals are connected to each other, the connection portion being located in a portion adjacent to the terminals.CN 116 111 268 A discloses a battery pack structure consisting of a housing, a battery module and a harness assembly. The battery module and the harness assembly are disposed in the housing. The harness assembly includes a flexible harness, a flat rigid harness, at least one high voltage jacket, at least one low voltage jacket, and a mounting support frame for securing the high and low voltage jackets to the housing. The mounting support frame, by its construction, allows physical separation between the high voltage harness and the low voltage harness. The flexible wiring harness is connected to the low voltage jacket and the flat rigid wiring harness is connected to the high voltage jacket. The flat rigid harness enables the high voltage harness to be converted from round to flat.US 2019 / 0 140 245 A1 discloses a vehicle having an electric drive train and a power distribution unit (PDU). The PDU includes a power protection circuit disposed in the electric drive train. This protection circuit is composed of a thermal fuse and a contactor connected in series. The PDU includes a high voltage input with an electrical interface for a high voltage source and a high voltage output with an electrical interface for a drive load. The current protection circuit electrically couples the high voltage input to the high voltage output and is at least partially integrated into a laminated layer of the PDU. The laminated layer comprises an electrically conductive current path arranged between two electrically insulating layers.It is the object of the invention to equip a high-voltage battery, in particular for a hybrid vehicle, with a plurality of power paths and at the same time to create a safety concept with a safe and compact design of the battery housing, so that greater flexibility is provided in the energy supply of a vehicle, in particular a hybrid vehicle, and at the same time high safety and simple assembly are ensured.This object is achieved according to the invention with respect to a high-voltage battery by the features of claim 1 and with respect to a battery housing by the features of claim 12. The other claims relate to preferred embodiments of the invention.The invention provides an improved safety concept for a high-voltage battery, in particular for use in hybrid vehicles, having a plurality of secondary power paths. The auxiliary power paths extend the functionality of the high-voltage battery and the configuration of the battery housing according to the invention simultaneously offers a robust and yet compact safety concept with a protective space for the safety elements of the auxiliary power paths. This ensures a reliable and reliable distribution of the electrical energy in the vehicle and enables the operation of different loads while simultaneously minimizing the risks associated with high voltage. The configuration according to the invention of the battery housing with a delimited region makes it possible to ensure that the battery functions reliably and meets all safety requirements. By integrating the safety elements of the secondary power paths into the battery housing, the requirements for simple mounting of the high-voltage battery in the vehicle are fulfilled.According to a first aspect, the invention provides a high-voltage battery, in particular for use in a hybrid vehicle. The high-voltage battery comprises a battery housing, wherein the battery housing encloses an interior space with battery cells arranged therein. The battery housing is formed in two parts with a first receiving space for receiving the battery cells and a second receiving space for receiving securing devices for a plurality of secondary power paths. A partition wall is arranged between the first receiving space and the second receiving space, wherein the partition wall has at least one recess for passing through at least one main power path for contacting the battery cells, and wherein the secondary power paths for electrically supplying different secondary consumers of a vehicle branch off from at least one main power path.In one development, it is provided that the high-voltage battery is designed as a lithium-ion battery.In an advantageous embodiment, it is provided that the battery housing consists of a light metal, in particular aluminum.In a further embodiment, it is provided that the battery housing is formed in one piece and is an aluminum die casting housing produced by die casting.Advantageously, it is provided that the battery housing for the arrangement of the battery cells in the first receiving space is oriented vertically and the main forming direction for forming the first receiving space lies in the Z direction in the die casting process, and that a cavity slide is used for forming the second receiving space in order to additionally demold the die casting housing in a second direction, in particular the Y direction.In particular, the battery housing is made of plastic.Advantageously, a separate fuse box for receiving fuses for the auxiliary power paths can be inserted into the second receiving space.In a development, it is provided that an electrically insulating component is arranged on the partition wall.In particular, the component is firmly connected to the partition wall, in particular by means of a screw connection, a clamping connection, a rivet connection or an adhesive connection, wherein the component is a plastic component produced by injection molding.Advantageously, a plurality of power bypass paths are arranged on the component, each of which paths is protected by a fuse.In a further embodiment, it is provided that the second receiving space is closed by a cover, wherein the cover is designed to be removable, so that the second receiving space is accessible for assembly and maintenance purposes, and that the cover is designed with recesses for the passage of the various auxiliary power paths.According to a second aspect, the invention provides a battery housing for a high-voltage battery. The battery housing is formed in two parts with a first receiving space for receiving the battery cells and a second receiving space for receiving securing devices for a plurality of secondary power paths, wherein a partition wall is arranged between the first receiving space and the second receiving space, and wherein the partition wall has at least one recess for passing through at least one main power path for contacting the battery cells.In a further development, it is provided that the battery housing consists of a light metal, in particular aluminum, or that the battery housing consists of plastic.In an advantageous embodiment, it is provided that the battery housing is formed in one piece and is an aluminum die casting housing produced by die casting.In a further embodiment, it is provided that the battery housing for the arrangement of the battery cells in the first receiving space is oriented vertically and the main forming direction for forming the first receiving space lies in the Z direction in the die casting process, and that a cavity slide is used for forming the second receiving space in order additionally to demold the die casting housing in a second direction, in particular the Y direction.The invention is explained in more detail below with reference to exemplary embodiments shown in the drawing.The following shows: FIG. 1 shows a schematic perspective illustration of a housing of a high-voltage battery with a separate fuse box according to the prior art; FIG. 2 shows a schematic perspective illustration of a housing according to the invention of a high-voltage battery; FIG. 3 shows a schematic perspective illustration of the housing according to the invention of a high-voltage battery from FIG. 2 with a greater number of secondary power paths.Additional characteristics, aspects and advantages of the invention or its embodiments will become apparent from the detailed description in connection with the claims.FIG. 1 shows a battery housing 20 of a high-voltage battery 10 according to the prior art. The battery housing 20 is in particular rectangular and contains the battery cells. The battery housing 20 has a recess 22 for a main power path 30, which branches into a plurality of auxiliary power paths 32 for the supply of auxiliary consumers such as air conditioning system, heating system and entertainment system. The individual auxiliary power paths 32 are each protected by contactors and fuses which are accommodated in an electrically insulating fuse box 40. However, the fuse box 40 is located outside the housing 20 and thus needs to be separately mounted in the vehicle mounting.The high-voltage battery 10 is, in particular, a hybrid high-voltage battery for a hybrid vehicle. A power path 30, 32 refers to the connection through which electrical energy is transferred from the battery 10 to various parts of the vehicle or to other electrical components. The main power path 30 and the further auxiliary power paths 32 typically consist of a robust, insulated high-voltage cable which transfers electrical energy from the high-voltage battery 10 to one or more loads in the vehicle. Because the main power path 30 and the other auxiliary power paths 32 operate at high voltages, special safety and design features are required to ensure safe operation. Thus, the high-voltage cables must have a high-quality insulation in order to avoid electrical leaks or short circuits.FIG. 2 shows a battery housing 70 according to the invention of the high-voltage battery 10. The first receiving space 73 and the second receiving space 74 are separated from each other by a partition wall 75. A recess 77 for at least one main power path is formed in the partition 75. This recess 77 is in particular circular.The battery housing 70 of the high-voltage battery 10 is made of a light metal in particular. Light metals are materials with low weight and high strength which are ideally suitable for use in vehicles. In particular, aluminum is used which is both light and strong and is frequently used in automobile construction.In particular, the battery housing 70 of the high-voltage battery 10 is an aluminum die casting housing produced in one piece by the die casting process. In the die casting process, molten aluminum is cast into a mold under high pressure, whereby the material rapidly and precisely assumes the desired shape. Die cast housings made of aluminum are stable and light, which is advantageous in particular for hybrid batteries.The battery housing 70 is oriented vertically for the arrangement of the battery cells in the first receiving space 73, such that the main forming direction lies in the Z direction in the die casting process. According to the invention, however, another main deformation direction can also be provided.To form the second receiving space 74, a cavity slide is used, which additionally demolds the die casting housing in a second direction, in particular the Y direction. Here too, within the scope of the invention, a direction deviating from the Y direction can be provided. A cavity slide is a mechanism that is used in die casting tools to move parts of the die casting mold to allow for complex geometries. The cavity slide serves to form the second cavity 74, which is not demoldable in the main direction of the die casting mold. It is decisive that the demolding of the battery housing 70 takes place in two directions, in a main direction for forming the first receiving space 73 and additionally in a second direction using a cavity slide for forming the second receiving space 74.However, within the scope of the invention, it can also be provided to produce the battery housing 70 from plastic. Plastic housings are lighter than metal housings and can be manufactured at lower cost, but may have lower strength and thermal conductivity than aluminum.The second receiving space 74 is designed in its dimensions to receive a separately designed fuse box. The fuse box is designed to be electrically insulating and, in particular, a plastic box produced by injection molding.Injection molding is a manufacturing process in which molten plastic is injected into a mold to produce a variety of products or components. It is particularly suitable for the production of parts with precise dimensions and complex geometries in large numbers. The injection molding process is also well suited for complex geometries, as the injection molds may include detailed structures and surface features. In addition, the injection molding method is cost-effective in producing large numbers.FIG. 3 shows an electrically insulating component 79 arranged on the partition wall 75, which preferably completely covers the partition wall 75 and is firmly connected to it, in particular by means of a screw connection, a clamping connection, a rivet connection or an adhesive connection. The component 79 is a plastic component produced in particular by injection molding.A plurality of secondary power paths 82 are arranged on the component 79, each of which is protected by a fuse 84. The secondary power paths 82 open into a first main power path 80 which is introduced into the battery housing 70 through the recess 77 for contacting with the battery cells. In addition, a second main power path 87 is provided, which is likewise introduced through the recess 77 into the battery housing 70 and is secured by a fuse, not shown in detail here.On the component 79 or within the second receiving space 74, further components, not shown here, such as sensors, can be accommodated. The second receiving space 74 is closed by a cover, not shown here, wherein the cover is removable, so that the second receiving space 74 is accessible for assembly and maintenance purposes. For the passage of the various secondary power paths 82, the cover is formed with recesses. The cover is likewise preferably a plastic cover produced by injection molding.The invention provides an improved safety concept for a high-voltage battery, in particular for use in hybrid vehicles, having a plurality of secondary power paths. The auxiliary power paths extend the functionality of the high-voltage battery and the configuration of the battery housing according to the invention simultaneously offers a robust and yet compact safety concept with a protective space for the safety elements of the auxiliary power paths. This ensures a reliable and reliable distribution of the electrical energy in the vehicle and enables the operation of different loads while simultaneously minimizing the risks associated with high voltage. The configuration according to the invention of the battery housing with a delimited region makes it possible to ensure that the battery functions reliably and meets all safety requirements. By integrating the safety elements of the secondary power paths into the battery housing, the requirements for simple mounting of the high-voltage battery in the vehicle are fulfilled.Reference numerals denote reference numerals10 High-voltage battery 20 Battery housing 22 Cutout 30 Main power path 32 Secondary power path 40 Fuse box 70 Battery housing 73 First accommodation space 74 Second accommodation space 75 Partition wall 77 Cutout 79 Component 80 First main power path 82 Secondary power path 84 Fuse 87 Second main power path

Claims

High-voltage battery (10), in particular for use in a hybrid vehicle, having a battery housing (70), wherein the battery housing (70) encloses an interior space with battery cells arranged therein, characterized in that the battery housing (70) is formed in two parts with a first receiving space (73) for receiving the battery cells and a second receiving space (74) for receiving securing devices for a plurality of auxiliary power paths (82), wherein a dividing wall (75) is arranged between the first receiving space (73) and the second receiving space (74), wherein the dividing wall (75) has at least one recess (77) for passing through at least one main power path (80, 87) for contacting the battery cells, and wherein the auxiliary power paths (82) for electrically supplying different auxiliary consumers of a vehicle branch off from at least one main power path (80).High-voltage battery (10) according to Claim 1, wherein the high-voltage battery (10) is designed as a lithium-ion battery.High-voltage battery (10) according to Claim 1 or 2, wherein the battery housing (70) consists of a light metal, in particular aluminum.High-voltage battery (10) according to Claim 3, wherein the battery housing (70) is formed in one piece and is an aluminium die casting housing produced by die casting.High-voltage battery (100) according to Claim 4, wherein the battery housing (70) is oriented vertically for the arrangement of the battery cells in the first receiving space (73) and the main forming direction for forming the first receiving space (73) lies in the Z direction by die casting, and wherein a cavity slide is used for forming the second receiving space (74) in order additionally to demold the die casting housing in a second direction, in particular the Y direction.High-voltage battery (10) according to one of Claims 1 to 5, wherein the battery housing (70) is composed of plastic.High-voltage battery (10) according to one of Claims 1 to 6, wherein a separate fuse box for accommodating fuses for which the bypass power paths (82) can be inserted into the second receptacle space (74).High-voltage battery (10) according to one of Claims 1 to 7, wherein an electrically insulating component (79) is arranged on the dividing wall (75).High-voltage battery (10) according to Claim 8, wherein the component (79) is fixedly connected to the dividing wall (75), in particular by means of a screw connection, a clamping connection, a rivet connection or an adhesive connection, and wherein the component (79) is a plastics component produced by injection moulding.High-voltage battery (10) according to Claim 8 or 9, wherein a plurality of secondary power paths (82) are arranged on the component (79), each of which secondary power paths is protected by a fuse (84).High-voltage battery (10) according to one of Claims 8 to 10, wherein the second receiving space (74) is closed by a cover, wherein the cover is designed to be removable, such that the second receiving space (74) is accessible for assembly and maintenance purposes, and wherein the cover is designed with recesses for the passage of the various secondary power paths (82).Battery housing (70) for a high-voltage battery (10), wherein the battery housing (70) is formed in two parts with a first receiving space (73) for receiving the battery cells and a second receiving space (74) for receiving securing devices for a plurality of secondary power paths (82), wherein a dividing wall (75) is arranged between the first receiving space (73) and the second receiving space (74), wherein the dividing wall (74) has at least one recess (77) for passing through at least one main power path (80, 87) for contacting the battery cells.Battery housing (70) according to Claim 12, wherein the battery housing (70) consists of a light metal, in particular aluminum, or wherein the battery housing (70) consists of plastic.The battery housing (70) according to claim 13, wherein the battery housing (70) is formed in one piece and is an aluminum die casting housing produced by die casting.Battery housing (70) according to Claim 14, wherein the battery housing (70) is oriented vertically for the arrangement of the battery cells in the first receiving space (73) and the main forming direction for forming the first receiving space (73) lies in the Z direction by die casting, and wherein a cavity slide is used for forming the second receiving space (74) in order additionally to demold the die casting housing in a second direction, in particular the Y direction.

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