Electrical energy storage

Abstract

Electrical energy storage device with a plurality of electrically interconnected individual cells arranged in a housing (2) by means of a cell holder (1), which are at least partially thermally coupled to a temperature control medium, wherein - the cell holder (1) is designed in the form of a frame with at least one component (K) arranged to optimise the flow of the tempering medium flowing around the individual cells at least in sections, with a number of receiving units (A) corresponding to the number of individual cells, wherein - a cover element (3) arranged or arrangeable on the cell holder (1) is provided for covering the individual cells and - the cell holder (1) and / or the cover element (3) melt or melts at a temperature value in the housing (2) which exceeds a predetermined temperature threshold, so that the spread of thermal runaway from one individual cell to an adjacent individual cell is inhibited, wherein the component (K) for optimising the flow of the temperature control medium has a flow-optimised contour which extends from an inlet opening (E) of the temperature control medium to an outlet opening (AO) of the temperature control medium within the housing (2), characterized in that the component (K) is designed such that the component (K) has a wedge shape.

Description

[0001] The invention relates to an electrical energy storage device comprising a plurality of electrically interconnected individual cells arranged in a housing by means of a cell holder, which are at least partially thermally coupled to a temperature control medium.

[0002] DE 10 2021 114 640 A1 discloses a battery and a motor vehicle equipped with the same. The battery has a housing with an inlet and an outlet for a dielectric temperature control medium for immersion temperature control of battery cells arranged in the housing. A plate-shaped cell holder is arranged in the housing. This is arranged between the inlet and the outlet in a flow path of the temperature control medium, viewed in a vertical direction of the battery cells. The cell holder has a plurality of receiving areas, spaced apart from one another perpendicular to the vertical direction, for one of the battery cells each. Furthermore, the cell holder has a hole pattern consisting of a plurality of passages for the temperature control medium arranged between the receiving areas. The hole pattern varies monotonically with the distance from the inlet to adjust the flow resistance of the cell holder for the temperature control medium.

[0003] Furthermore, DE 10 2018 117 601 B4 describes a battery with a temperature control device. The battery comprises a battery module having a plurality of electrically conductively connected cylindrical battery cells, which has a temperature control device for controlling the temperature of the battery cells and a container having a fluid space into which the battery cells extend and which has an inlet and an outlet for a fluid of a fluid circuit. The fluid is an electrically non-conductive fluid.The container has a cell holder with a plurality of openings through which respective end faces of the battery cells of the at least one battery module protrude into the fluid space of the container and which enclose respective lateral surfaces of the battery cells in a liquid-tight manner, wherein the cell holder has a further opening through which a contact element protrudes into the fluid space of the container and which encloses a lateral surface of the contact element in a liquid-tight manner. A connecting device arranged in the fluid space of the container electrically connects respective poles of the end faces of the battery cells protruding into the fluid space of the container to the contact element protruding into the container. The battery has two of the battery modules, between which the container composed of two of the cell holders is arranged, into which the respective end faces of the battery cells protrude from two opposite sides.

[0004] US 2018 / 0 358 671 A1 relates to a battery pack for supporting one or more battery cells within the battery pack, comprising a chassis defining a body for holding the battery cells. The chassis may comprise a set of vertical battery cell holders adapted to hold the battery cells. A series of horizontal passages may be provided in the chassis between the vertical battery cell holders. A cap assembly may be provided at one end of the battery cells and inside the housing to provide ventilation of the battery cells through the battery cell holders.

[0005] DE 10 2019 121 669 A1 relates to a receiving structure for battery cells, in particular a high-voltage battery for a motor vehicle, comprising a cell holder made of foam with recesses for receiving and securing the respective battery cells. The cell holder is shaped such that, when the battery cells are arranged as intended in the recesses, at least one area of ​​the respective battery cells is left open, allowing an electrically non-conductive cooling medium to flow around this area. Furthermore, a battery, in particular a high-voltage battery for a motor vehicle, is provided, comprising at least one such receiving structure, as well as a method for producing a receiving structure for battery cells.

[0006] The invention is based on the object of providing a novel electrical energy storage device for a vehicle.

[0007] The object is achieved according to the invention by an electrical energy storage device which has the features specified in claim 1.

[0008] Advantageous embodiments of the invention are the subject of the subclaims.

[0009] An electrical energy storage device comprises a plurality of electrically interconnected individual cells arranged in a housing by means of a cell holder, which are at least partially thermally coupled to a temperature control medium. According to the invention, the cell holder is designed in a frame-shaped manner with at least one component arranged to optimize the flow of the temperature control medium flowing around the individual cells at least partially, having a number of receiving units corresponding to the number of individual cells. A cover element arranged or arrangeable on the cell holder is provided to cover the individual cells. The cell holder and / or the cover element melt or melts at a temperature value in the housing that exceeds a predetermined temperature threshold, so that the spread of thermal runaway from one individual cell to neighboring individual cells is inhibited.To optimize the flow of the temperature control medium, the component has a flow-optimized contour which extends from an inlet opening of the temperature control medium to an outlet opening of the temperature control medium within the housing, wherein the component is designed such that the component has a wedge shape.

[0010] By designing the electrical energy storage device in this way, where the cell holder performs the function of holding and positioning the cells and optimizing the flow of the temperature control medium, and the cover element, which can be formed integrally with the cell holder, largely prevents the thermal runaway of an individual cell from spreading to neighboring individual cells when thermal runaway occurs, the number of parts / components of the electrical energy storage device can be reduced. This results in a reduction in the complexity of the parts / components and, consequently, in the complexity of the electrical energy storage device, thereby achieving cost reduction.

[0011] In one embodiment, the component for optimizing the flow of the temperature control medium comprises a flow-optimized component, for example, an inclined plane, which extends from an inlet opening of the temperature control medium to an outlet opening of the temperature control medium within the housing, for example, having a sloping ramp shape from the inlet opening to the outlet opening. In other words, the cell holder can have at least one partial area that slopes downwards in a ramp shape from an inlet opening to an outlet opening, so that a triangular surface can result when viewed from the side of the cell holder.By means of this flow-optimized contour, a flow direction of the tempering medium is predetermined, so that the flow is optimized and essentially all individual cells of the electrical energy storage device are at least partially flowed around by the tempering medium, in particular for dissipating heat loss arising during charging and discharging.

[0012] In a further embodiment, the cell holder is formed from a particle foam and / or a plastic and / or an endothermically reacting wax, wherein the cell holder has a certain, in particular heat-resistant, stability, so that the cell holder retains its shape when the individual cells and / or the temperature control medium are heated, so that the holding and positioning of the individual cells over their service life as well as the optimized flow of the temperature control medium can be ensured to the greatest extent possible.

[0013] In one possible embodiment, the cell holder and / or the cover element are / is designed to be oil-resistant, in particular in such a way that the cell holder does not absorb, i.e., does not take up, oil. This ensures that, if, for example, oil is used as a temperature control medium, it remains in a temperature control circuit that runs through the housing of the electrical energy storage device and is not absorbed by the cell holder.

[0014] In one embodiment, depending on the configuration of the individual cells, the cover element has recesses arranged at regular intervals for arranging cell connectors, for example, on an upper side of the cover element, for example, on at least one edge region of the cover element. For example, it is also possible to integrate the cell connectors into the cover element to reduce handling processes. In particular, electrical poles of an individual cell with a prismatic shape are arranged at least partially within a recess, so that the cell connectors can be connected to the individual cells by means of a welding process.

[0015] Embodiments of the invention are explained in more detail below with reference to drawings.

[0016] Showing: Fig. 1 schematically shows a perspective view of an exploded view of an embodiment of a cell holder for insertion into a housing of an electrical energy storage device, Fig. 2 schematically shows a perspective view of an exploded view of a further embodiment of a cell holder for insertion into a housing of an electrical energy storage device and Fig. 3 schematically shows a further perspective view of the cell holder in the further embodiment according to Fig. 2.

[0017] Corresponding parts are provided with the same reference numerals in all figures.

[0018] Fig. 1 shows a perspective view of an exploded view of an embodiment of a cell holder 1 for insertion into a housing 2 of an electrical energy storage device, in particular for a vehicle.

[0019] The electrical energy storage device has a number of electrically interconnected individual cells arranged in the housing 2 by means of the cell holder 1, which are at least partially thermally coupled to a temperature control medium, in particular have the temperature control medium, which is designed as oil, flowing around them. The individual cells are temperature-controlled by means of the temperature control medium, i.e., heated or cooled to an optimized operating temperature, wherein any heat loss generated during charging and discharging of the individual cells is dissipated by means of the temperature control medium. For this purpose, the cell holder 1 is designed to be oil-resistant, so that the cell holder 1 does not absorb the oil as a temperature control medium. For example, the cell holder 1 is made of a particle foam and / or a plastic and / or an endothermically reacting wax.

[0020] In order to reduce the number of components of the electrical energy storage device, the latter, in particular the cell holder 1, is designed as described below.

[0021] The cell holder 1 is frame-shaped and has a component K with a number of receiving units A corresponding to the number of individual cells. In each receiving unit A, an individual cell is arranged according to Fig. 1, a prismatic single cell, inserted and held in position.

[0022] The housing 2 has an inlet opening E arranged in an upper region of a side wall and an outlet opening AO arranged in a lower region of an opposite side wall of the housing 2. Other positions of the inlet opening E and the outlet opening for the temperature control medium are also possible and depend on the channel layout of a temperature control medium circuit.

[0023] To optimize the flow of the temperature control medium, component K is designed such that it has a wedge shape and is accordingly inclined. When the cell holder 1 is inserted into the housing 2, an inclined plane extends from the inlet opening E to the outlet opening AO. The cell holder 1 thus has a flow- and temperature-optimized geometry, which can vary, for example, depending on the design of the individual cells, the module shape, in particular the shape of the electrical energy storage device, etc.

[0024] A cover element 3 is arranged or can be arranged on the frame-shaped cell holder 1, wherein the cell holder 1 and the cover element 3 can also be designed as one component.

[0025] According to the Fig. In the embodiment of the cell holder 1 shown in Figure 1, the cover element 3 has a number of regularly spaced recesses A1 for arranging cell connectors (not shown in detail). The individual cells are electrically interconnected by means of the cell connectors.

[0026] As mentioned above, the individual cells are designed according to the Fig. 1, the individual cells are designed as prismatic individual cells. In this form of individual cells, the electrical poles and a venting opening, which opens to release a venting gas when excess pressure is present in the individual cell, are arranged or formed on the top side of the individual cell.

[0027] In the event that a single cell thermally breaks through, the venting opening opens due to the overpressure, so that the venting gas is released towards the cover element 3. As a result, a material of the cover element 3 heats up in such a way that the cover element 3 melts in the area of ​​the venting opening of this thermally broken single cell, so that a through hole D is created in the cover element 3 and the venting gas can escape upwards, as is shown for example in the Fig. 1. The venting gas therefore does not flow toward neighboring individual cells, which can significantly reduce the risk of thermal runaway spreading.

[0028] Fig. 2 shows a perspective view of an exploded view of a further embodiment of the cell holder 1 for insertion into a housing 2 of an electrical energy storage device, wherein the cell holder 1 is provided for holding and positioning individual cells designed as round cells.

[0029] Fig. 3 shows a perspective further view of the cell holder 1 in the further embodiment, wherein a bottom side of the cell holder 1 is shown.

[0030] In this further embodiment, the cell holder 1 also has the component K with the receiving units A for inserting the individual cells, wherein the component K comprises the inclined plane for optimizing the flow of the temperature control medium and for optimizing the temperature control of the individual cells.

[0031] In such round cells, the venting opening and a cell contact for electrically connecting the individual cells are located on opposite sides of the individual cell. Circular recesses A1 are incorporated into the cover element 3 for electrically connecting these individual cells.

[0032] An opposite side of the cell holder 1 is formed from the material from which, according to the Fig. 1, the cover element 3 is formed.

[0033] If one of the individual cells experiences thermal runaway, the cell holder 1 melts in the area of ​​that individual cell due to the hot venting gas escaping from the individual cell. The venting gas can thus escape through a through hole D created in the cell holder 1 in the area of ​​that individual cell. The venting gas is guided away from the individual cells via this through hole D in the cell holder 1, thus largely preventing the thermal runaway from spreading to neighboring individual cells.

[0034] The concept described here can be scaled to any size and can also be used in cell-to-pack, cell-to-chassis, and other battery concepts with direct / indirect temperature control. However, with indirect temperature control of the individual cells, the design of cell holder 1 for flow optimization is omitted, with the focus on cell positioning and preventing thermal propagation. List of reference symbols 1 cell holder 2 housings 3 Cover element A recording unit AO outlet opening A1 recess D Through hole E Inlet opening K component

Claims

[1] Electrical energy storage device with a plurality of electrically interconnected individual cells arranged in a housing (2) by means of a cell holder (1), which are at least partially thermally coupled to a temperature control medium, wherein - the cell holder (1) is designed in the form of a frame with at least one component (K) arranged to optimise the flow of the tempering medium flowing around the individual cells at least in sections, with a number of receiving units (A) corresponding to the number of individual cells, wherein - a cover element (3) arranged or arrangeable on the cell holder (1) is provided for covering the individual cells and - the cell holder (1) and / or the cover element (3) melts or melts at a temperature value in the housing (2) that exceeds a predetermined temperature threshold, so that the propagation of thermal runaway from one individual cell to an adjacent individual cell is inhibited, wherein the component (K) for optimising the flow of the temperature control medium has a flow-optimised contour which extends from an inlet opening (E) of the temperature control medium to an outlet opening (AO) of the temperature control medium within the housing (2), characterized by that the component (K) is designed such that the component (K) has a wedge shape. [2] Electrical energy storage device according to claim 1, characterized by that the cell holder (1) is formed from a particle foam and / or a plastic and / or an endothermically reacting wax. [3] Electrical energy storage device according to one of the preceding claims, characterized bythat the cell holder (1) and / or the cover element (3) are or are designed to be oil-resistant. [4] Electrical energy storage device according to one of the preceding claims, characterized by that the tempering medium is an oil. [5] Electrical energy storage device according to one of the preceding claims, characterized by that the cover element (3), depending on an embodiment of the individual cells, has recesses (A1) arranged at regular intervals from one another for the arrangement of cell connectors. [6] Electrical energy storage device according to one of the preceding claims, characterized by in that in the event of thermal runaway of at least one individual cell of the individual cells, the cell holder (1) and / or the cover element (3) are or are designed to melt in a region of the thermally runaway individual cell in order to form a through-hole (D) in the cover element (3), so that a venting gas can escape upwards.

Images