Battery module, method for providing monitoring function for battery module, battery system and electric vehicle

Abstract

The invention provides a battery module, a method for providing a monitoring function for the battery module, a battery system and an electric vehicle. The battery module comprises: a plurality of battery cells; a bus bar contacting the plurality of battery cells; a thermally and electrically conductive sleeve thermally and electrically connected to the bus bar; and a circuit board fixed to the bushing by a fixing element such that the bushing separates the circuit board from the bus bar. The circuit board includes: a temperature sensor in thermal contact with the bus bar through a bushing; and a voltage signal line in electrical contact with the bus bar through the bushing.

Description

TECHNICAL FIELD

[0001] Aspects of embodiments of the present disclosure relate to a battery module, a method for providing a monitoring function for a battery module, a battery system, and an electric vehicle. BACKGROUND

[0002] Recently, vehicles for transporting goods and people using electric power as a power source have been developed. An electric vehicle is a car that is permanently or temporarily propelled by an electric motor using energy stored in a rechargeable (or secondary) battery. An electric vehicle can be powered only by a battery (a so-called battery electric vehicle or "BEV"), or can include a combination of an electric motor and, for example, a conventional internal combustion engine (a so-called plug-in hybrid electric vehicle or "PHEV"). BEVs and PHEVs use high-capacity rechargeable batteries designed to provide electric power for propulsion over sustained periods of time.

[0003] Generally, a rechargeable (or secondary) battery cell includes an electrode assembly including a positive electrode, a negative electrode, and a separator interposed between the electrodes. A solid or liquid electrolyte allows ions to move during charging and discharging of the battery cell. The electrode assembly is located (or housed) in a case, and electrode terminals located outside of the case establish an electrically conductive connection with the electrodes. The shape of the case can be, for example, cylindrical or prismatic.

[0004] A battery module is formed of a plurality of battery cells connected together in series or in parallel. For example, a battery module is formed by interconnecting electrode terminals of a plurality of battery cells in a number and configuration according to a desired amount of electric power, and is used to provide a high-power rechargeable battery.

[0005] A battery module can be constructed in a block design or in a modular design. In the block design, each battery cell is incorporated into a common current collector structure and a common battery management system, and cells of the battery cell are arranged in a case. In the modular design, a plurality of battery cells are connected together to form a sub-module, and several sub-modules are connected together to form a battery module. In automotive applications, a battery system typically includes a plurality of battery modules connected together in series to provide a desired voltage.

[0006] A battery pack is a group of any number of (typically identical) battery modules or individual battery cells. The battery modules or individual battery cells can be constructed in series, in parallel, or a mix of both, to provide a desired voltage, capacity, and / or power density. The components of a battery pack include the individual battery modules and interconnects that provide electrical conductivity between the battery modules.

[0007] The battery system can also include a battery management system (BMS), which is any suitable electronic system configured to manage rechargeable battery cells, battery modules, and battery packs, such as by protecting the batteries from operating outside of their safe operating area, monitoring their state, calculating secondary data, reporting that data, controlling their environment, authenticating them, and / or balancing them. For example, the BMS can monitor the state of the battery cells represented by voltage (e.g., total voltage of the battery pack or battery module and / or voltage of individual battery cells), temperature (e.g., average temperature of the battery pack or battery module, coolant inlet temperature, coolant output temperature, or temperature of individual battery cells), coolant flow (e.g., flow rate and / or coolant pressure), and current. Additionally, the BMS can calculate values based on the above parameters, such as minimum and maximum battery cell voltage, state of charge (SoC), or depth of discharge (DoD), to indicate the state of charge of the battery cells, state of health (SoH; various defined measures of the remaining capacity of the battery cell expressed as a percentage of the initial capacity), state of power (SoP; amount of power available for a defined time interval given the current power usage, temperature, and other conditions), state of safety (SoS), maximum charge current as a charge current limit (CCL), maximum discharge current as a discharge current limit (DCL), and internal impedance of the cell (to determine open circuit voltage).

[0008] The BMS can be centralized, such that a single controller is connected to the battery cells by a large number of wires. In other examples, the BMS can be distributed, with a BMS board installed at each cell, and only a single communication cable between the battery cells and the controller. In other examples, the BMS can have a modular construction including some controllers that each handle (e.g., monitor and / or control) multiple (or a group of) cells, while communicating between the controllers. A centralized BMS is the most economical, but has the lowest scalability and suffers from a large number of wires. A distributed BMS is the most expensive, but is the simplest to install and provides the cleanest assembly. A modular BMS provides a compromise between the other two topologies.

[0009] The BMS can protect the battery pack from operating outside of its safe operating area. Operation outside of the safe operating area can be indicated by overcurrent, overvoltage (during charging), overtemperature, under-temperature, overpressure, and ground fault or leakage current detection. The BMS can prevent the battery from operating outside of its safe operating parameters by including internal switches (e.g., relays or solid state devices) that disconnect if the battery is operated outside of its safe operating parameters, requesting the device to which the battery is connected to reduce or even terminate use of the battery, and actively controlling the environment, such as by a heater, fan, air conditioner, or liquid cooling.

[0010] Static control of battery power output and charging can not be sufficient to meet the dynamic power demands of various power consumers connected to the battery system. Therefore, a stable exchange of information between the battery system and the controllers of the power consumers can be used. This information includes the actual state of charge (SoC), potential electrical performance, charging capability and internal resistance of the battery system and the actual or predicted power demand or surplus of the power consumers. Therefore, the battery system typically includes a battery management system (BMS) for obtaining and processing such information on the system level and can also include a plurality of battery module managers (BMM) as part of the battery modules of the system and obtaining and processing related information on the module level. For example, the BMS typically measures the system voltage, the system current, the local temperature at different locations inside the system housing and the insulation resistance between the live components and the system housing. Furthermore, the BMM typically measures the individual cell voltage and temperature of the battery cells in the battery module.

[0011] Therefore, a BMS is provided for managing a battery pack, such as by protecting the battery from operating outside its safe operating area, monitoring its state, calculating auxiliary data, reporting that data, controlling its environment, authenticating it and / or balancing it.

[0012] In case of an abnormal operating state (e.g. an abnormal operating state is detected), the battery pack should be disconnected from the loads connected to the terminals of the battery pack. Therefore, the battery system can also include a battery disconnect unit (BDU) electrically connected between the battery module and the terminals of the battery system. The BDU is the main interface between the battery pack and the electrical system of the vehicle. The BDU includes an electromechanical switch that disconnects or closes a high current path between the battery pack and the electrical system. The BDU provides feedback, such as voltage and current measurements, to a battery control unit (BCU) accompanying the battery module. The BCU controls the switch in the BDU using a low current path based on the feedback received from the BDU. The main functions of the BDU can include controlling the current flow between the battery pack and the electrical system and current sensing. The BDU can also manage additional functions, such as external charging and pre-charge.

[0013] The BMS is essential for the safe operation and optimal performance of rechargeable battery cells and helps to reduce or minimize the likelihood of thermal runaway. For example, if the BMS detects that the temperature is too high, it can regulate the temperature by controlling a cooling fan. If the battery cells cannot be cooled sufficiently and the safety situation recovers, the BMS can shut down the necessary battery cells to protect the entire system.

[0014] In order to acquire information of a battery cell in a battery module, the battery cell can be contacted by a monitoring device. A common approach is to contact a plurality of terminals of the battery cell and a busbar carrying the current of the plurality of battery cells. Key information is for example the temperature of the busbar and the voltage of the busbar. Inside a conventional BDU, temperature sensing and high voltage voltage sensing is used. A connection is provided as a high voltage cable for voltage sensing and a flexible print for temperature sensors. Therefore, a complex assembly is required because the high voltage cable and the flexible print have to be installed. In other examples, a conductive tab has to be welded to the busbar. Furthermore, electronics are usually screwed to the housing. SUMMARY

[0015] Embodiments of the present disclosure provide an improved connection structure for acquiring key information related to a battery cell.

[0016] The present disclosure is defined by the appended claims and their equivalents. The following description is subject to this limitation. Any disclosure beyond the scope of the claims and their equivalents is intended for illustrative and comparative purposes.

[0017] According to one embodiment of the present disclosure, a battery module comprises a plurality of battery cells, a busbar contacting the plurality of battery cells, a thermally and electrically conductive sleeve thermally and electrically connected to the busbar, and a circuit board fixed to the sleeve by a fixing element such that the sleeve spaces the circuit board from the busbar. The circuit board comprises a temperature sensor thermally connected to the busbar by the sleeve and a voltage signal line electrically connected to the busbar by the sleeve.

[0018] According to an embodiment of the present disclosure, a method for providing a monitoring function to the above-mentioned battery module comprises the steps of fixing a sleeve to a busbar, placing a circuit board comprising a temperature sensor and a voltage signal line onto the sleeve such that a board opening in the circuit board is aligned with the sleeve, and fastening the sleeve to the circuit board by a fixing element to electrically and thermally connect the busbar to the circuit board by the sleeve.

[0019] Other aspects and features of the present disclosure can be learned from the following description. BRIEF DESCRIPTION OF DRAWINGS

[0020] Aspects and features of the present disclosure will become apparent to those of ordinary skill in the art by reference to the following detailed description of embodiments of the present disclosure, taken in conjunction with the accompanying drawings in which: Figure 1 is a schematic overview of a battery module according to an embodiment.

[0021] Figure 2 is a schematic cross-section of a sleeve according to an embodiment.

[0022] Figure 3A is a schematic cross-section of a sleeve according to another embodiment.

[0023] Figure 3B is a schematic cross-section of a bushing according to another embodiment.

[0024] Figure 3C is a schematic cross-section of a bushing according to another embodiment.

[0025] Figure 4 is a perspective schematic view of a bushing between a busbar and a circuit board according to an embodiment.

[0026] Figure 5 is a graph showing temperature on a circuit board at a hot spot and at a remote temperature sensor over time.

[0027] Figure 6 is a flowchart describing a method according to an embodiment.

[0028] Figure 7 is a schematic view of a battery system according to an embodiment.

[0029] Figure 8 is a schematic view of an electric vehicle according to an embodiment. DETAILED DESCRIPTION

[0030] Reference will now be made in detail embodiments, examples of which are illustrated in the accompanying drawings. The aspects and features of the present disclosure and methods for realizing the same will be described with reference to the accompanying drawings. However, the present disclosure can be embodied in various different forms and should not be construed as being limited to the embodiments set forth herein. Rather, these embodiments are provided as examples so that the aspects and features of the present disclosure will be thorough and complete, and will fully convey the aspects and features of the present disclosure to those skilled in the art.

[0031] Therefore, processes, elements, and techniques that are sufficiently fully understood by those having ordinary skill in the art will not be described or will be only briefly described. It will be understood that when an element or layer is referred to as being “on” another element or layer, “connected to” or “coupled to” another element or layer, it can be directly on, directly connected or directly coupled to the other element or layer, or one or more intervening elements or intervening layers can also be present. When an element or layer is referred to as being “directly on” another element or layer, “directly connected to” or “directly coupled to” another element or layer, there are no intervening elements or intervening layers present. For example, when a first element is described as being “coupled” or “connected” to a second element, the first element can be directly coupled or connected to the second element, or the first element can be indirectly coupled or connected to the second element via one or more intervening elements.

[0032] In the figures, the size of various elements, layers, etc., can be exaggerated for clarity. Like reference numbers signify like elements in all figures. As used in herein, the term “and / or” includes any and all combinations of one or more of the associated listed items. In addition, use of “can” in describing embodiments of the present disclosure relates to “one or more embodiments of the present disclosure.” Expressions such as “at least one of (a), (b), and / or (c)” when preceding a list of items, modify the list of items as a whole rather than each item in the list. For example, the expression “at least one of a, b, or c” means a, b, c, a and b, a and c, b and c, or a, b, and c. As used herein, the term “use” and variations thereof can be considered synonymous with the term “utilize” and variations thereof.

[0033] It will be understood that, although the terms first, second, third, etc. can be used herein to describe various elements, components, regions, layers and / or sections, these elements, components, regions, layers and / or sections should not be limited by these terms. These terms are used to distinguish one element, component, region, layer or section from another element, component, region, layer or section. Thus, a first element, a first component, a first region, a first layer or a first section discussed below could be termed a second element, a second component, a second region, a second layer or a second section without departing from the teachings of example embodiments.

[0034] For ease of description, spatial relative terms, such as “below”, “under”, “lower”, “above”, “upper” and the like, can be used herein for describing the relationship of one element or feature to another element or feature as shown in the figures. It will be understood that the spatial relative terms are intended to encompass different orientations of the device in use or operation, in addition to the orientations depicted in the figures. For example, if a device in the figures is turned over, elements described as “below” or “under” other elements or features would then be oriented “above” the other elements or features. Thus, the term “below” can encompass both an orientation of above and below. The device can be otherwise oriented (rotated 90 degrees or at other orientations) and the spatial relative descriptors used herein interpreted accordingly.

[0035] The terminology used herein is for the purpose of describing embodiments of the present disclosure and is not intended to be limiting of the present disclosure. As used herein, the singular forms "a," "an," and "the" are intended to include the plural forms as well, unless the context clearly indicates otherwise. It will be further understood that the terms "comprises," "comprising," "includes," and / or "including," when used herein, specify the presence of stated features, integers, steps, operations, elements, and / or components but do not preclude the presence or addition of one or more other features, integers, steps, operations, elements, components, and / or groups thereof.

[0036] Those of ordinary skill in the art will appreciate that, in light of the overall disclosure, each suitable feature of various embodiments of the present disclosure can be combined or combined with each other in part or in whole, and can be technically interlocked and operated in various suitable ways, and each embodiment can be implemented independently of each other or in combination with each other in any suitable way, unless otherwise stated or implied.

[0037] As used herein, the terms "substantially," "about," and similar terms are used as an approximation term and not as an exact term, and are intended to account for the inherent deviations in measured or calculated values that would be recognized by those of ordinary skill in the art. Moreover, if the term "substantially" is used in reference to a characteristic that can be expressed as a numerical value, the term "substantially" indicates a range of values + / - 5% of the value.

[0038] Unless otherwise defined, all terms (including technical and scientific terms) used herein have the same meaning as commonly understood by one of ordinary skill in the art to which this present disclosure belongs. It will be further understood that terms, such as those defined in commonly used dictionaries, should be interpreted as having a meaning that is consistent with their meaning in the context of the relevant art and / or the present disclosure, and will not be interpreted in an idealized or overly formal sense unless expressly so defined herein.

[0039] Electronic or electrical devices and / or any other related devices or components according to embodiments of the present disclosure described herein can be implemented with any suitable hardware, firmware (e.g., application specific integrated circuits), software, or a combination of software, firmware, and hardware. Moreover, various components of these devices can be implemented on a flexible printed circuit film, a tape carrier package (TCP), a printed circuit board (PCB), or formed on one substrate. Electrical connections or interconnections described herein can be implemented by wires or conductive elements, such as on a PCB or another circuit carrier. The conductive elements can include metallization, e.g., surface metallization and / or pins, and / or can include conductive polymers or ceramics. Additional electrical energy can be transmitted via wireless connections, such as by using electromagnetic radiation and / or light.

[0040] According to embodiments of the present disclosure, a battery module includes a plurality of battery cells, a busbar contacting the plurality of battery cells, a thermally and electrically conductive (or thermally and electrically conductive) sleeve thermally and electrically connected to (e.g., fixed to) the busbar, and a circuit board fixed to the sleeve by a fixing element such that the sleeve spaces the circuit board from the busbar. The circuit board includes a temperature sensor in thermal contact with the busbar through the sleeve and a voltage signal line in electrical contact with the busbar through the sleeve.

[0041] By applying the sleeve to the busbar, an electrical connection from the busbar to the electronics is provided. No additional components such as a high voltage (HV) cable for voltage sensing or a flexible print (e.g., a flexible printed circuit board (FPCB)) for temperature sensing are needed and are replaced by the sleeve. The electrical and thermal connection is established via the connection of the sleeve to the busbar.

[0042] The sleeve can be made of a high thermally and electrically conductive (or high thermally and electrically conductive) material. A high thermally and electrically conductive material is characterized by low losses. For example, a high thermally conductive material is characterized by exhibiting a relatively low temperature difference between two opposite ends along its longitudinal direction compared to other materials. Further, a high electrically conductive material is characterized by having a relatively low potential difference between two opposite ends along its longitudinal direction compared to other materials. The busbar can be an electrically conductive longitudinal extension for connecting terminals of the plurality of battery cells. The busbar can be made of metal. By directly connecting the sleeve to the busbar, no additional components for contacting the busbar are needed.

[0043] The cross-sectional shape of the sleeve can be circular, square, oval, rectangular, hexagonal, or any other suitable shape.

[0044] The busbar can also be bent in the vertical direction in segments. The circuit board can be a printed circuit board (PCB), a multi-layer PCB and / or a flexible PCB. A relatively thin PCB has the advantage that its temperature changes quickly according to its surroundings. In other words, the thermal responsiveness is improved. The circuit board can have a metallization around the connection points with the sleeve. Metal is a good heat conductor, and therefore the metallization can be thicker than in a normal circuit board. In some embodiments, the metallization can only be thicker near the sleeve and the temperature sensor than in other areas of the circuit board (e.g. can be locally thicker). The temperature sensor can be an SMD sensor and can be arranged within a radius in the range of about 0.5 mm to about 4 mm, centered on the center of the sleeve. In some embodiments, the radius can be in the range of about 0.6 mm to about 1.5 mm. The closer the temperature sensor is to the sleeve, the smaller the error (or difference) in the temperature measurement of the sleeve, and therefore the smaller the error (or difference) in the temperature measurement of the busbar. The temperature measurement can be limited to a temperature of about 140 °C. In some embodiments, the temperature measurement is limited to about 130 °C. The voltage signal line can be made of a conductive material with high electrical conductivity, in order to minimize losses along the voltage line. Thereby, an accurate measurement of the voltage of the busbar is feasible. The sleeve can be a solid body for spacing the busbar from the circuit board and connecting the busbar to the circuit board. The sleeve can be partially hollow. The hollow part of the sleeve can be used by a fixing element (e.g. can be engaged with the fixing element) to fix the circuit board to the sleeve. However, the sleeve can also have a protruding part that extends through the circuit board. The fixing element can then interact with the protruding part, thereby fixing the circuit board to the sleeve.

[0045] By fixing the circuit board to its designated mounting position in the battery module, while establishing an electrical connection and a thermal connection.

[0046] According to another embodiment, the sleeve is fixed to the busbar in a form-fit, force-fit and / or material- engagement manner.

[0047] The sleeve can be fixed to the busbar in various ways. For example, the sleeve can be fixed in a form-fit. The form-fit can be provided by a hook on one component and a corresponding hole (or opening) in the other component that snap and connect when moved together vertically. In other embodiments, the locking can be achieved by a rotational movement of the sleeve relative to the busbar.

[0048] In some embodiments, the sleeve can be fixed in a force fit manner. This can be provided by press fitting the sleeve into an opening in the bus bar. In other embodiments, the bus bar can have a plurality of smaller through holes, and a protruding pin of the sleeve can be press fit in the through holes. In other embodiments, the bus bar can include a protrusion, and the sleeve can be press fit on the protrusion. The force fit connection allows heat to be conducted through a large contact surface between the two components. Furthermore, because no machining steps are required, assembly is fast.

[0049] In some embodiments, the sleeve can be fixed in a material bond manner. This can be provided, for example, by gluing, welding, or brazing. Because the contact surface is increased, heat transfer is improved.

[0050] All of the above fixation methods can be combined in any suitable variation.

[0051] According to an embodiment, the circuit board has a thickness, and the sleeve spaces the circuit board from the bus bar by at least twice the thickness of the circuit board.

[0052] The spacing of the circuit board from the bus bar prevents the circuit board from being heated by the bus bar. The circuit board also includes other components that are sensitive to heat. Thus, it is desirable to avoid or minimize heat transfer to the circuit board. For example, heat can be transferred only to the circuit board and temperature sensors in the vicinity of the sleeve. This can be provided by configuring the circuit board to thermally isolate the area around the board opening from other circuit elements on the circuit board that are not directly related to temperature and voltage measurements.

[0053] According to an embodiment, the sleeve spaces the circuit board from the bus bar by at least about 8 mm. In another embodiment, the spacing is at least about 10 mm. In one embodiment, the spacing is at least about 12 mm.

[0054] In an embodiment, the sleeve has a sleeve opening that extends from a first end of the sleeve facing the circuit board toward the bus bar.

[0055] The sleeve opening can be blind (e.g., can be a blind hole or an opening) and can not extend completely through the sleeve. The sleeve opening can have an internal threading for holding a fixation element, such as a screw for example. The cross-sectional shape of the sleeve opening can be circular or square, or can be any other suitable shape. In one embodiment, the shape of the sleeve opening corresponds to the shape of the sleeve.

[0056] According to another embodiment, the sleeve opening extends from the first end to a second end of the sleeve opposite the first end.

[0057] For example, the sleeve opening can be a through hole.

[0058] In an embodiment, the sleeve can be a hollow cylinder having the sleeve opening.

[0059] In a cross-sectional view, the wall thickness of the sleeve at the sleeve opening can be between about 0.5 mm and about 3 mm. In some embodiments, the wall thickness can be between about 1 mm and about 2 mm. In one embodiment, the wall thickness is between about 1.3 mm and about 1.5 mm. The wall thickness can be constant throughout the sleeve to facilitate the machining of the sleeve. However, in other embodiments, the wall thickness can not be constant, thus the sleeve can provide a form fit for the fixation element. Furthermore, a larger wall thickness has a better thermal conductivity.

[0060] According to embodiments, the fixation element comprises a screw, a bolt, a plug, a nut, a clamp or a rivet.

[0061] In some embodiments, a portion of the fixation element is configured to be fixedly connected in the sleeve opening.

[0062] In embodiments, the circuit board forms part of the battery disconnect unit, the battery management unit and / or the cell supervision circuit.

[0063] Due to the integration into one of the above-mentioned units, a reliable operation is achieved due to the short signal distance and the elimination of interconnections.

[0064] According to embodiments, a temperature difference between a portion of the circuit board in direct contact with the sleeve and a portion of the circuit board in direct contact with the temperature sensor is less than about 1 K. In another embodiment, the temperature difference is less than about 0.5 K.

[0065] The sleeve transfers heat from the busbar towards the circuit board. For example, the sleeve is a heat source attached to the circuit board and heat spreads from it towards the circuit board. The temperature difference relates to a temperature difference in the circuit board between the heat source and the temperature sensor, which represents a measurement error of the temperature sensor. Thus, a small temperature difference is advantageous.

[0066] In embodiments, the sleeve is a metal sleeve. Metal provides high thermal and electrical conductivity as well as strength and elasticity to withstand temporary stresses, for example during assembly. The metal can be selected from stainless steel, aluminum, brass, copper, gold, silver or any combination or alloy thereof.

[0067] In other embodiments, the sleeve can be made of carbon fiber. Carbon fiber has comparable features in terms of thermal and electrical conductivity as metal. The carbon fiber can be coated with one of the above-mentioned metals. Thus, the strength of the carbon fiber can be combined with the high electrical and thermal conductivity of the metal.

[0068] According to embodiments, the voltage signal line is a high-voltage sense line.

[0069] The high-voltage sensing line does not carry a significant current sufficient to perform a voltage measurement, i.e. carries a very low current. For example, the measurement can be a high-ohmic voltage measurement. However, the voltage sensing is not limited to the vicinity of the bushing and can be performed remotely from the location of the other electronic components where the monitoring unit is located.

[0070] According to another embodiment of the present disclosure, a method for providing a monitoring function of a battery module as described above is provided. First, a bushing is fixed to a busbar. Second, a circuit board comprising a temperature sensor and a voltage signal line is placed on the bushing such that a board opening in the circuit board is aligned with the bushing. Third, the bushing is fastened to the circuit board by a fixing element. Thereby, the busbar is electrically and thermally connected to the circuit board via the bushing.

[0071] In some embodiments, the method consists only of the three steps described above. Thereby, the electrical, thermal and mechanical connection of the circuit board is provided by only one fastening action. Thus, an efficient assembly and cost reduction can be achieved. Furthermore, in some embodiments, the board opening in the circuit board and the bushing opening in the bushing are aligned such that the fixing element can be inserted into both openings. In a top view of the bushing, the alignment reference point of the bushing can be the center of the bushing. Then, the fixing element can be inserted into the aligned openings. Furthermore, in some embodiments, one or more of these process steps can be automated.

[0072] Another embodiment of the present disclosure relates to a battery system comprising a plurality of battery modules as described above.

[0073] The battery system can comprise at least two battery modules. In another embodiment, the battery system comprises at least three battery modules. In yet another embodiment, the battery system comprises at least four battery modules.

[0074] Another embodiment of the present disclosure relates to an electric vehicle comprising a battery module or a battery system as described above.

[0075] The electric vehicle can comprise exactly one battery module or battery system. The module or system can be arranged centrally at a lower position in the vehicle. In another embodiment, the electric vehicle can comprise two or more battery modules or battery systems. These modules or systems can be arranged at different positions within the vehicle, allowing a flexible weight and space adjustment.

[0076] Figure 1 is a schematic overview of a battery module 100 according to an embodiment of the present disclosure. The battery module 100 comprises a housing 12, a plurality of battery cells 10, a busbar 1 and a circuit board 3. As will be explained with reference to Figure 2In more detail, the busbar 1 is connected to the circuit board 3 by a sleeve 2. At least one sleeve 2 is located between the circuit board 3 and the busbar 1. The position of the sleeve 2 is not limited by the position of the battery cells 10. Further, a monitoring unit can be included. The monitoring unit can be a battery disconnect unit, a battery management unit, or a cell supervisory circuit that processes data received from the battery cells 10. The monitoring unit can include the circuit board 3. In the illustrated embodiment, seven battery cells 10 are shown. However, the number of battery cells 10 is not limited thereto and can include any suitable number of battery cells 10. Further, even though the battery cells 10 are shown to be arranged adjacent to each other in a longitudinal direction (e.g., x-direction) of the battery module 100, the arrangement direction and configuration are merely examples and the present disclosure is not limited thereto. For example, the battery cells 10 can be arranged in two or more stacked rows. The direction of stacking refers to, for example, a y-direction that is perpendicular to the longitudinal direction (e.g., x-direction) and the vertical direction (e.g., z-direction) in Figure 1 The busbar 1 can be configured to fit the arrangement of the battery cells 10 such that the terminals of a plurality or all of the battery cells 10 are connected.

[0077] Figure 2 is a schematic cross-section of a sleeve 2 according to an embodiment. The description with respect to Figure 1 applies in the following. In the illustrated embodiment, the busbar 1 has an opening 11 into which the sleeve 2 is inserted. The sleeve 2 can have a sleeve opening 21 that can extend through the sleeve 2, i.e., the sleeve opening 21 is a through-hole. The sleeve 2 can be a hollow cylinder. However, in some embodiments, the sleeve opening 21 can not extend completely through the sleeve 2, but can only partially extend from a first end face 23 of the sleeve 2 facing the circuit board 3 towards the busbar 1. In some embodiments, the sleeve opening 21 can be divided into two parts separated by a solid part of the sleeve 2 (e.g., in a cross-sectional view of the sleeve 2). The remaining wall thickness w of the sleeve 2 around the sleeve opening 21 can be in a range of about 0.5 mm to about 3 mm. In some embodiments, the wall thickness can be in a range of about 1 mm to about 2 mm. In one embodiment, the wall thickness can be in a range of about 1.3 mm to about 1.5 mm. The sleeve opening 21 near the opening 11 in the busbar 1 is configured to provide (or form) a force-fit connection between the busbar 1 and the sleeve 2. For example, the sleeve can be press-fit into the opening 11. The press-fit connection provides a contact surface along the entire opening 11 between the busbar 1 and the sleeve 2. The sleeve 2 can be a metal sleeve. This allows for low thermal and electrical resistance between the components. In some embodiments, the busbar 1 and the sleeve 2 can be fixed in a material-bonding manner, such as by way of example in a weld, a solder, or a glue. Thereby, the contact area between the two components is increased, and thus, the thermal and electrical conductivity is further increased and the mechanical strength is increased. Other connection methods will be described below with respect to Figure 3A andFigure 3B It is discussed that other connection methods can also be applied to the shown embodiments. The sleeve 2 has a first end face 23 and a second end face 24 which can be parallel to each other. The distance between the two end faces 23 and 24 can be equal to the length of the sleeve 2.

[0078] The sleeve 2 supports the circuit board 3 at its first end face 23. The circuit board 3 has a board opening 31 for the fixation of the circuit board 3 with the sleeve 2. In one embodiment, the board opening 31 in the circuit board 3 is at least as large as the sleeve opening 21. However, the board opening 31 is not larger than the outer diameter of the sleeve 2 (e.g. in the x-y plane). For example, the first end face 23 forms a support face and / or a contact face for the circuit board 3. Through this support face and / or contact face, an electrical and thermal contact is established between the two components. Furthermore, a fixation element (e.g. a mechanical fixation element) is provided to fix the circuit board 3 to the sleeve 2. The fixation element can be a separate component or can be integrally formed with the circuit board 3 or the sleeve 2. In the shown embodiment, the fixation element is a screw 41. Thereby, the electronic (i.e. the circuit board 3) is directly mounted to the busbar 1 using a threaded connection. The sleeve opening 21 can have a corresponding inner thread 22. However, the screw 41 can also be a self-cutting (or self-tapping) screw, such that the sleeve opening 21 can be provided (or formed) without the inner thread 22. In other embodiments, the fixation element can be a bolt or a rivet. The fixation element fixes the circuit board 3 to the sleeve 2 such that the circuit board 3 is firmly fixed. The fixation element also ensures the thermal and electrical conductivity between the sleeve 2 and the circuit board 3. With the threaded connection, all temperature sensing connections and high voltage sensing connections have been provided and additional mounting steps are omitted. The circuit board 3 comprises a temperature sensor 5 which is configured to contact the busbar 1 in a thermally conductive manner through the sleeve 2. For example, the temperature sensor 5 is provided for measuring the temperature of the busbar 1 without directly contacting the busbar 1. In order to make the temperature measurement accurate, the temperature sensor 5 is positioned in the vicinity of the board opening 31. The temperature sensor 5 can be positioned on the upper side or the lower side of the circuit board 3. The vicinity of the board opening 31 can mean that the position of the temperature sensor 5 is within a circle centered with the center of the sleeve 2 having a radius in the range of about 0.5 mm to about 4 mm. In some embodiments, the radius can be in the range of about 0.6 mm to about 1.5 mm. This ensures a small temperature difference between the contact face of the circuit board 3 with the sleeve 2 and another contact face of the circuit board 3 with the temperature sensor 5. The temperature difference between the two contact faces can be less than about 1 K. In another embodiment, the temperature difference can be less than about 0.5 K.

[0079] The circuit board 3 includes a voltage signal line 6, which is configured to conductively contact the busbar 1 through the sleeve 2. Therefore, the voltage signal line 6 can contact the upper and / or lower side of the circuit board 3 near the board opening 31. Furthermore, the voltage signal line 6 can extend to the upper, lower, and / or intermediate layers of the circuit board 3. The voltage signal line 6 can directly contact the sleeve 2 or indirectly contact the sleeve 2 via a fixing element. Additionally, the voltage signal line 6 can be a high-voltage sensing line.

[0080] The sleeve 2 separates the circuit board 3 from the busbar 1 by a distance d. This distance d can be equal to or greater than approximately 8 mm, approximately 10 mm, or approximately 12 mm. In some embodiments, the distance d can be at least twice the thickness t1 of the circuit board 3. Furthermore, the distance d can be less than the length of the sleeve 2. In some embodiments, the distance d can be equal to the length of the sleeve 2 minus the thickness t2 of the busbar 1. This can be when the sleeve 2 extends through the busbar 1 and its second end face 24 is flush with the underside of the busbar 1.

[0081] Figures 3A to 3C This is a schematic cross-section of the sleeve 2 according to other embodiments. Unless otherwise explicitly stated, the description of all previous figures applies accordingly. The sleeve 2 is fixed to the manifold 1 by form-fitting, force-fitting, and / or material-bonding methods. Figure 3A The sleeve 2 shown has a sleeve opening 21 that extends only to a certain extent (or length) into the body of the sleeve 2. For example, the solid body of the sleeve 2 (i.e., the portion of the sleeve 2 without the sleeve opening 21) can be enlarged, i.e., have a length of approximately 10%, approximately 20%, or approximately 30% of the distance d. However, the structure of the first end face 23 of the sleeve 2 is similar to... Figure 2 The structure shown is the same. This embodiment is identical to the one referenced above. Figure 2 The difference in the described embodiment lies in the structure of the second end face 24. Here, the second end face 24 is formed as follows (e.g., in...). Figure 2 In the xy-plane, a lower protrusion 26 has a vertical extension smaller than the cross-section of the middle and / or top of the sleeve 2. In this embodiment, the opening in the busbar can be smaller than... Figure 2 The opening in the illustrated embodiment mates with the lower protrusion 26. The fit can be tight, for example, to provide a force-fit connection, or it can be loose, to provide rough positioning and subsequent material-bonded fastening. Compared to Figure 3A , Figure 3B It was flipped 180°. The second end face 24 and... Figure 2The embodiment shown is the same. However, the top of the sleeve 2 has an upper protrusion 25. The upper protrusion 25 may be provided with external threads, horizontal through holes, and / or fixing grooves to which a fixing element can be connected. In this embodiment, the fixing element may be a nut, a clamp, a clip, etc. In some embodiments, the fixing element may be integrally formed, that is, the upper protrusion may have a conical shape configured for fixing the circuit board. Figure 3C The sleeve 2 shown is similar to Figure 3B The sleeve shown is an example. However, the upper protrusion 25 is provided with at least one protrusion groove 27 extending (e.g., extending in the xy plane) through the upper protrusion 25 to form two protrusion legs 210. Multiple protrusion grooves 27 can form multiple protrusion legs 210. The protrusion legs 210 can have a square cross-sectional shape and can have one or more first hooks 28 formed on their outer edges. The first hooks 28 can snap onto the upper side of the circuit board 3 to connect the circuit board 3 to the sleeve 2. The first hooks 28 are examples of form-fitting fixing elements. The protrusion grooves 27 provide flexibility to the protrusion legs 210 to bend inwards and subsequently outwards after the protrusion legs 210 have passed through the circuit board 3. At least one leg groove 211 is formed on the lower side of the sleeve 2 as a through-hole in the horizontal direction (e.g., in the xy plane) to form two or more lower legs 212 of the sleeve 2. The lower leg 212 has one or more second hooks 29 at its outer corner. Similar to the first hook 28, the second hooks 29 latch onto the underside of the busbar 1 when the lower leg 212 passes through the opening 11 in the busbar 1. The lower leg 212 can also be secured by a material bonding method. Additionally, Figures 2 to 3C The features described in the embodiments shown regarding the sleeve can be combined with each other or modified to achieve similar embodiments.

[0082] Figure 4 This is a schematic perspective view of the sleeve 2 between the busbar 1 and the circuit board 3. Figure 4 The structure shown is similar to Figures 1 to 3C Consistent, and all preceding descriptions apply accordingly. However, for convenience, certain components, such as fixing elements, temperature sensors 5, details of sleeves 2, or voltage signal lines 6, may be omitted. Busbar 1 may be bent. This may be due to the specific arrangement of the battery cells 10 or for reaching the terminals of the battery cells 10. Furthermore, the circuit board 3 may have an extension larger than busbar 1 in the width direction and may contact multiple busbars 1 through multiple sleeves 2. In such an embodiment, multiple temperature sensors 5 and multiple voltage signal lines 6 may be present.

[0083] Figure 5is a plot of the temperature on the circuit board 3 over time at a circuit board hot spot on the circuit board 3 and at the temperature sensor 5 remote from the circuit board hot spot, the circuit board hot spot being directly adjacent to the point of connection of the sleeve 2 to the circuit board 3. The sleeve 2 conducts heat from the busbar 1 to the circuit board 3 and the circuit board 3 transfers heat to the temperature sensor 5. The circuit board hot spot can be the board connection portion 32 (see e.g. Figure 2 ). The plot is obtained by FEM analysis of the circuit board 3 around the sleeve hot spot of the sleeve 2 as described above. The temperature curve at the circuit board hot spot is indicated by the number 300, the temperature curve at the temperature sensor 5 is indicated by the number 302 and the charging current curve is indicated by the number 304. At t=0, the temperature is about 30°C. The battery module 100 is charged with a charging current of 250 A, which leads to an increase in temperature of the busbar 1 and, in turn, to an increase in temperature of the circuit board hot spot on the circuit board 3 and of the temperature sensor 5. At a maximum temperature of about 100°C, the temperature difference in this example is less than about 2 K. For example, the temperature difference between the part of the circuit board 3 that is in direct contact with the sleeve 2 and the part of the circuit board 3 that is in direct contact with the temperature sensor 5 is less than about 2 K. The temperature difference can be less than about 3% compared to the temperature measured directly at the circuit board hot spot. In some embodiments, the temperature difference can be less than about 2%. By placing the temperature sensor 5 close to the circuit board hot spot, the temperature difference can be reduced. In turn, the temperature difference can even be smaller, such as about 0.5 K. When the temperature difference is small, the time delay between the temperature rise at the busbar 1 and the sensing of the temperature by the temperature sensor 5 can be negligible.

[0084] Figure 6 is a flow chart describing a method 200 for providing monitoring functionality for a battery module 100. The description of the previous figures can apply accordingly. The method comprises, in a first step 201, fixing the sleeve 2 to the busbar 1. As described above with respect to Figures 2 to 3C , the sleeve 2 can be fixed to the busbar 1 in various ways. In a second step 202, the circuit board 3 comprising the temperature sensor 5 and the voltage signal line 6 is placed onto the sleeve 2 such that the board opening 31 in the circuit board 3 and the sleeve 2 are aligned. When the sleeve 2 has the sleeve opening 21 at the first end face 23 of the sleeve 2, the two openings are aligned and the fixing element extends into both openings. When the sleeve 2 has the upper protrusion 25, the protrusion extends through the board opening 31 in the circuit board 3 and the fixing element can go onto or into the upper protrusion 25. In both configurations, in a third step 203, the sleeve 2 is fixed to the circuit board 3 by the fixing element. Thereby, the circuit board 3 is thermally and electrically connected to the busbar 1 by the sleeve 2. No additional mounting steps are required, thus, an easy mounting is achieved.

[0085] Figure 7is a schematic view of a battery system 102 according to an embodiment of the present disclosure. The description of all previous figures applies accordingly. In this embodiment, the battery system 102 comprises two battery modules 100, but the battery system 102 is not limited thereto. The battery system 102 can also comprise three, four or more battery modules 100.

[0086] Figure 8 is a schematic view of an electric vehicle 110 according to an embodiment of the present disclosure. The description of all previous figures applies accordingly. In this embodiment, the electric vehicle 110 comprises at least a battery module 100 for supplying energy to the electric vehicle 110. In another embodiment, the electric vehicle 110 can comprise a battery system 102. The battery modules 100 of the battery system 102 can be distributed within the electric vehicle 110.

[0087] Some reference signs 1 busbar; 11 opening 2 sleeve; 21 sleeve opening 22 inner thread; 23 first end face 24 second end face; 25 upper protrusion 26 lower protrusion; 27 protrusion groove 28 first hook; 29 second hook 210 protrusion leg; 211 leg groove 212 lower leg; 3 circuit board 31 board opening; 32 board connection portion 41 screw; 5 temperature sensor 6 voltage signal line; 10 battery cell 12 housing; 100 battery module 102 battery system; 110 electric vehicle 200 method for providing monitoring functionality for a battery module 201 fixing the sleeve to the busbar 202 placing the circuit board onto the sleeve 203 fastening the sleeve to the circuit board 300 temperature profile at the hot spot of the circuit board 302 temperature profile at the temperature sensor 304 charging current profile.

Claims

1. A battery module, the battery module comprising: Multiple battery cells; The busbar contacts the plurality of battery cells; A thermally and electrically conductive sleeve is thermally and electrically connected to the busbar; as well as A circuit board, fixed to the sleeve by a fixing element, such that the sleeve separates the circuit board from the busbar, the circuit board comprising: The temperature sensor is in thermal contact with the busbar through the sleeve; as well as The voltage signal line makes electrical contact with the busbar through the bushing.

2. The battery module according to claim 1, wherein, The sleeve is fixed to the busbar by a form fit, a force fit, and / or a material bonding method.

3. The battery module according to claim 2, wherein, The force fitting method includes pressing the sleeve into the opening in the manifold.

4. The battery module according to claim 1, wherein, The circuit board has a thickness, and the sleeve separates the circuit board from the busbar by at least twice the thickness of the circuit board.

5. The battery module according to claim 1, wherein, The sleeve has a sleeve opening that extends from a first end face of the sleeve facing the circuit board toward the busbar.

6. The battery module according to claim 5, wherein, The sleeve opening extends from the first end face to the second end face of the sleeve opposite to the first end face.

7. The battery module according to claim 1, wherein, The sleeve is a hollow cylinder with a sleeve opening.

8. The battery module according to claim 7, wherein, The fixing elements include screws, bolts, plugs, nuts, clamps, or rivets.

9. The battery module according to claim 1, wherein, The circuit board forms part of a battery disconnection unit, a battery management unit, and / or a cell monitoring circuit.

10. The battery module according to claim 1, wherein, The temperature difference between the portion of the circuit board that directly contacts the sleeve and the portion of the circuit board that directly contacts the temperature sensor is less than 1K.

11. The battery module according to claim 1, wherein, The sleeve is a metal sleeve.

12. The battery module according to claim 1, wherein, The voltage signal line is a high-voltage sensing line.

13. A method for providing monitoring functionality for a battery module according to claim 1, the method comprising the following steps: Secure the sleeve to the manifold; The circuit board, including the temperature sensor and the voltage signal line, is placed on the sleeve, such that the board opening in the circuit board is aligned with the sleeve. as well as The sleeve is fastened to the circuit board by the fixing element so that the busbar is electrically and thermally connected to the circuit board through the sleeve.

14. A battery system comprising a plurality of battery modules according to claim 1.

15. An electric vehicle comprising the battery system according to claim 14.

16. An electric vehicle comprising the battery module according to claim 1.

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