Propagation test cell for secondary electric battery cells and cell modules

Abstract

The invention relates to a propagation test cell (3), comprising: - a first housing part (4), having a substantially cuboid outer shape and comprising at least one drive mechanism (6) disposed wholly or partly inside and designed to move a nail (5) along a movement axis (MA); - a nail (5), which is mechanically coupled to the drive mechanism (6) and is arranged so that the central axis of the longitudinal extension of the nail extends coaxially with the movement axis (MA);and - a second housing part (7), comprising a reference surface (SC) parallel to and directed opposite a reference surface (SB) of the first housing part (4) and in contact with it, and comprising at least one conduit (8) wholly or partially open or closed and coaxial with the axis of movement (MA) of the nail (5), said conduit having a conduit cross-sectional area greater than the diameter of the shank of the nail (5); wherein the dimensions of the outer shape of the propagation test cell (3) correspond to a multiple of the respective dimensions of a battery cell (2) with which the propagation test cell (3) can be arranged within a cell module (1), such that the propagation test cell (3) can be replaced with at least one additional battery cell (2) or with several of them within a cell module (1).;

Description

Technisches Gebiet

[0001] The invention relates to the technical field of verifying the functionality of secondary battery cells, in particular the performance of a propagation test. Stand der Technik

[0002] The propagation of secondary battery cells describes the effect of thermal runaway, in which an electrical short circuit occurs within a battery cell due to contamination on the separator or external mechanical damage. The resulting short-circuit current can heat the damaged area, damaging surrounding areas and other battery cells, and potentially causing further short circuits. This damage can spread across a cell module, releasing the energy stored in the entire battery in a short period of time.Accordingly, a propagation test is known as a method for checking secondary electrical battery cells and cell modules with regard to mechanical impairment, such as the intrusion or penetration of foreign bodies, dendrite formation or cell aging, which can lead to an internal electrical short circuit of at least one battery cell.

[0003] The propagation test is standardized, for example, in DIN EN 62619 or GB 38031-2020 as a dispersion test. In this test, a nail, preferably made of conductive and unalloyed steel and insulated from the rest of the test setup, partially or completely penetrates a battery cell or cell module. Alternatively, the nail can enclose a ceramic housing component or sheath, with only the tip of the nail made of steel or an electrically conductive material, so that the nail is insulated from the cell wall upon penetration. The geometric dimensions of the nail, the penetration depth, and the penetration velocity are parameters specified in the respective test standard.Generally, the nail comprises at least one shaft designed as a pin, which is specifically engineered to withstand the mechanical stress of penetrating or passing through at least one other battery cell. A propagation test is considered passed if, in the event of an electrical short circuit, no further battery cells of a cell module undergo thermal short circuits. Further results may include deformation or mechanical stress, temperature development as a function of time, the electrical voltage before and after the test of the battery cell or cell module, and other parameters.

[0004] Devices intended to enable a reproducible propagation test are known from the prior art. For example, German patent application CN106272165A discloses a square battery pin detection clamp by which largely square battery cells can be clamped, and in which the propagation test is supported by a steel pin guide mechanism according to the invention. Utility model CN201096874Y discloses a nail puncture tester in which battery cells are mechanically clamped as the test object in an external device, and a nail is guided to the test object by a hydraulically actuated guide device. Patent specification CN105068013B discloses a corresponding device with pneumatic actuation of the nail.

[0005] Patent specification US10718816B2 discloses a device in which a conductive nail is provided with an electrically insulated sheath, wherein the sheath and nail together penetrate a battery cell and the nail is only forced out of the sheath inside the battery cell, thus creating a short circuit between an anode and a cathode. The electrically conductive nail is coupled to measuring devices so that the voltage resulting across the nail and the short circuit can be measured.

[0006] Document CN107421682A discloses a device for initiating an internal short circuit in a battery cell during the manufacturing process, comprising a mechanism that is activated by a gas pressure generated during the filling of the battery cell with an electrolyte.

[0007] Document CN201945527U discloses a device for performing a needle impact test on a battery cell, wherein a battery is clamped into a test setup and punctured using a needle impact device.

[0008] Document KR20150054371A discloses a battery penetration test device with a sample chamber wherein pressure in the sample chamber can be released to the outside, with a pin holding unit for performing a vertical movement within the sample chamber and with a test pin installed in a lower end of the pin holding unit to penetrate a sample.

[0009] From the perspective of safety considerations regarding thermal runaway in secondary electrical battery cells, two things are useful: firstly, the most realistic possible generation of an internal short circuit, and secondly, the measurement of the propagation test results directly at the point of damage. However, all devices and methods known from the prior art have in common that a nail or other physical element is inserted into a battery cell or cell module from the outside, which entails several disadvantages. For example, the temperature and chemical decomposition cannot propagate uniformly from the point of damage in all directions, sealing of the external puncture site is required, and it is not possible to record measurements such as temperature, deformation, or mechanical stress directly at the point of stress.If thermal runaway is to be triggered by heating, a thermal energy input from the neighboring battery cells is also unavoidable, which leads to thermal runaway of more than one battery cell and to faulty measurement results. Offenbarung der Erfindung

[0010] The present invention is based on the objective of providing a propagation test cell that is arranged within a cell module instead of one or more battery cells and via which a propagation test can be initiated from within. This objective is achieved by a propagation test cell according to claim 1. 1 as well as a method according to the patent claim 10This problem is solved by the propagation test cell comprising a mechanism for inserting a nail into an adjacent battery cell, as well as integrated temperature and pressure measuring points. The intention of the invention is now to be able to test a cell module, whereby the propagation test can be initiated without external damage to the cell module. This results in the following advantages: No external mechanical stress on the cell module; no external sealing of a puncture point or the cell module is necessary; short circuit is initiated within the battery cell or cell module; propagation of thermal runaway in all spatial directions of the cell module can be realistically represented; temperature profile and mechanical pressure are measured directly at the point of damage using integrated temperature and pressure measuring points; thermal and mechanical behavior of the original battery cells can be represented within the propagation test cell

[0011] The following detailed description of the invention is supported by the illustrations below, which show FIG. 1A a propagation test cell replacing a single battery cell as well as FIG. 1B a propagation test cell replacing two battery cells in a cell module, FIG. 2A the basic structure of a propagation test cell in exploded view as well as FIG. 2B the reference geometry of the outer shape of the propagation test cell.

[0012] According to FIG. 1A und FIG. 1B comprises a cell module 1 a large number of battery cells 2, which can be stacked in a known manner and electrically connected to form a battery pack. Advantageously, at least one of the battery cells is now 2 within the cell module 1 by a propagation test cell according to the invention 3 substitutable, so that it, like a dummy cell, has technical properties on the basis of which the propagation test cell 3 the corresponding physical properties of the entire cell module 1 compared to a cell module 1 without propagation test cell 3The propagation test cell according to the invention is not affected or only slightly affected and, secondly, comprises a mechanism for initiating a propagation test. To fulfill these technical functions, the propagation test cell according to the invention has... 3 Features that are explained in detail below.

[0013] According to FIG. 2A The propagation test cell includes 3 a first housing part 4, which has a substantially cuboid outer shape. The substantially cuboid outer shape refers to the preferred application of the propagation test cell. 3 within a cell module 1, in which individual battery cells 2They have a generally cuboid shape, for example, comprising a generally square or rectangular base. The exact geometric design of the geometric shape or base of the battery cells used. 2 However, this plays a subordinate role, since the external shape of the propagation test cell according to the invention is 3 that of the additional battery cells used in the application 2 The shape of the additional battery cells is required for the initialization of the propagation test. 2 and thus of the first housing part 4 only of importance insofar as a nail 5, actuated by a thrust mechanism 6, from the propagation test cell 3 out into an adjacent battery cell 2 penetrates, whereby the aforementioned adjacent battery cell 2with at least one surface of its outer shape in contact with an outer surface of the propagation test cell 3 that the corresponding surfaces are arranged opposite each other, at least with a small distance between them.

[0014] According to FIG. 2B The spatial design of the propagation test cell according to the invention can be described 3 in a Cartesian coordinate system ( x, y, z ) represent, whereby for the further course of the description it is stipulated that the base area of ​​the first housing part 4 a substantially square or rectangular shape that is between the corner points B 111 , B 211 , B 212 , B 121 is stretched and thus the reference side SB of the first housing part 4 forms. The propagation test cell according to the invention 3 It also includes a second housing part. 7,which preferably also has a substantially square or rectangular base, which in particular preferably corresponds to the base of the first housing part 4 corresponds to the reference surface. SC of the second housing part 7 To support the following description, the base area between the corner points is defined. C 121 , C 221 , C 222 , C 122 is stretched across the base of the second housing part. 7 However, it can have any other shape, provided that it does not exceed the dimensions of the base of the first housing part. 4 does not exceed, so that the external shape of the entire propagation test cell 3 further to one or more battery cells 2 corresponds or these in their entirety by one or more battery cells 2 is substitutable.

[0015] The nail 5,which, during a propagation test, caused an internal short circuit in a neighboring battery cell 2 The nail, which is intended to generate [a specific electrical conductivity], comprises an electrically conductive material and is preferably made of unalloyed steel. The specific dimensions of the nail... 5 are generally determined by the relevant testing standards or regulations for carrying out the propagation test and are additionally based on the external shape of the battery cells. 2 of the applied cell module 1. According to applicable standards, the nail includes 5 In a preferred embodiment, the shank has a diameter of 1 mm to 20 mm, particularly preferably 3 mm to 8 mm, and the shank end has a conical angle of preferably 20° to 60°. Alternatively, any other geometric dimension of the nail is possible. 5to be used insofar as it is set up to provide at least one anode and one cathode of each of the propagation test cells 3 adjacent battery cell 2 to penetrate or cause an internal short circuit in a said battery cell 2 to produce.

[0016] The first housing part 4 the propagation test cell according to the invention 3 includes at least one propulsion mechanism 6, which is completely or partially inside that first housing part 4 is arranged and set up to hold the nail 5 along an axis of movement MA, the one orthogonal to the reference surface of the first housing part SB corresponds to moving, whereby the movement of the nail 5 preferably in the direction of the second housing part 7 This occurs. Consequently, the thrust mechanism is 6an independent device within the propagation test cell according to the invention 3, which fulfills the technical task of driving the nail 5 into at least one adjacent battery cell 2 to push the cells so that at least one anode and one cathode are electrically bridged, but preferably at least 10–90% of the cell thickness is penetrated. The thrust mechanism 6 Accordingly, it comprises a fully or partially self-contained system with mechanical, hydraulic, pneumatic, electrical, or magnetic components. The detailed design of the thrust mechanism 6 is not the subject of the invention; rather, the intention of the invention is to incorporate a corresponding mechanism into the first housing part. 4 the propagation test cell according to the invention 3 to integrate. To fulfill this task, the thrust mechanism can be used. 6in one embodiment completely in the first housing part 4 be integrated, preferably via a corresponding recess or cavity in the material of the first housing part 4, corresponding, for example, to the representation in FIG. 2A , the recess is a cuboid structure within the first housing part 4 schematically indicated, which has a physical connection to the front surface of the first housing part 4 includes the front surface. FIG. 2B exemplified by the area defined by the corner points B 211 , B 221 , B 222 , B 212 is stretched out.

[0017] In one embodiment, the propagation test cell comprises 3 at least one test interface 9, which are located on at least one end face of the first housing part 4 is arranged and has a physical connection to the thrust mechanism 6 and / or to functional elements such as temperature10 and the pressure measuring points 11 produces, so that the propulsion mechanism 6 via that test interface 9 can be activated and / or electrical connections to the temperature- 10 and the pressure measuring points 11 are able to be discharged to the outside. The test interface 9 It essentially fulfills two functions. Firstly, it enables the operation of the propulsion mechanism. 6 and secondly, this allows for further mechanical or electrical interfaces of functional elements, such as the aforementioned temperature 10 and / or pressure measuring points 11 to be set up for testing. Actuation of the thrust mechanism. 6 This can be done mechanically, hydraulically, pneumatically, electrically or magnetically, thus defining the test interface 9 can be designed accordingly. In one embodiment, in which the propulsion mechanism6 If the test interface is mechanically actuated, it can be used. 9 merely comprise a mechanical recess or through-hole, which is, for example, designed to act as a mechanical guide for mechanical components such as levers, linkages, transmission mechanisms, or others. In an alternative embodiment, in which the thrust mechanism 6 The test interface can be operated hydraulically or pneumatically. 9 pneumatic or hydraulic piping systems are included, for example, to supply the appropriate pneumatic or hydraulic fluids to the propulsion mechanism. 6 to supply. In an alternative embodiment, in which the propulsion mechanism 6 The test interface can be operated electrically or magnetically. 9 For example, it could be designed as a cable routing system or directly in the form of electrical cables. Alternatively, the test interface can 9any further design features to create a functional interface between the testing environment and the propulsion mechanism 6 to produce. Additionally, the test interface can 9 further connections of the aforementioned type include interfaces between the test environment and other functional elements such as temperature 10 and / or pressure measuring points 11 to produce.

[0018] The nail 5 is technically connected to the propulsion mechanism 6 coupled. The technical coupling between nail 5 and propulsion mechanism 6 preferably a mechanical connection. In one embodiment, the nail 5 mechanically with at least one component of the thrust mechanism 6 coupled. In an alternative embodiment, the nail 5mechanically coupled to at least one adapter component, which is coupled to at least one component of the propulsion mechanism 6 mechanically connected. Generally, the mechanical coupling between the nail 5 and propulsion mechanism 6 set up to nail 5 before activation of the thrust mechanism 6 completely or partially within the first housing part 4 to fix and through the work performed by the actuated propulsion mechanism 6 on its axis of movement MA to move. According to the invention, the axis of movement corresponds to MA an orthogonal to the reference surface SB of the first housing part 4, through which the nail 5 in the aforementioned orthogonal direction from the reference surface SB away and in the direction of the corresponding surface of at least one adjacent battery cell 2is moved so that the angle of entry of the nail into the adjacent battery cell 2 is perpendicular in an advantageous manner, so that the kinetic energy of the nail is transferred 5 This results in the greatest possible pressure on the adjacent battery cell. 2 exerted and simultaneously its trajectory after penetrating the aforementioned battery cell 2 is stabilized.

[0019] In one embodiment, the thrust mechanism comprises 6, which is located within a recess of the first housing part 4 is arranged to have an opening to the surface of the first housing part 4, preferably at its reference surface SB, whose surface dimensions are at least larger than the cross-sectional area of ​​the nail 5 are, so that the aforementioned nail 5, due to the activation of the thrust mechanism 6 and in its movement on the axis of movement MA, the aforementioned opening can pass unhindered. In an embodiment in which the thrust mechanism 6 a mechanical actuation includes the opening to the reference surface SB of the first housing part 4 Dimensions include those designed to accommodate mechanical components of the thrust mechanism. 6 completely or partially from the corresponding recess within the first housing part 4 to move out so that the nail 5 on the axis of movement MA is arranged to be movable. In one embodiment, in which the propulsion mechanism 6 If it is arranged to be activated hydraulically or pneumatically, the opening can be positioned relative to the reference surface. SB of the first housing part 4 Dimensions include those designed to accommodate the recess of the thrust mechanism. 6to seal against leakage of hydraulic or pneumatic fluid from the environment, for example via a suitable fit and additional sealing elements, to seal the cell wall of the adjacent battery cell 2 to prevent the escape of reaction gases that develop as a result of thermal runaway. Alternatively, the opening can include guide elements designed to prevent the nail from escaping. 5 in its movement on the axis of movement MA to support and / or guide, for example through a suitable fit.

[0020] Alternatively, and advantageously according to the invention with regard to ensuring unimpeded movement of the nail. 5 on the axis of movement MA The second housing part includes 7 a passage, in the form of a through-hole 8, which is designed to allow movement of the nail 5from inside the thrust mechanism 6 and thus of the first housing part 4 out into at least one adjacent battery cell 2 to enable. The diameter of the through-hole 8 is therefore at least larger than the diameter of the shaft or part of the nail. 5, which the second housing part 7 This happens. In an advantageous embodiment, the through-hole comprises 8 a suitable fit, so that the nail 5 or the part of it which forms the through-hole 8 This happens, and its movement is guided. In an alternative advantageous embodiment, the second housing part comprises 7 further elements which have a specified fit and guide the nail 5 in its movement on the axis of movement MA Additional support is available. Alternatively, any further modification of the through-hole is possible.8 applicable insofar as the nail 5 this unhindered in its movement on the axis of motion MA can happen. The nail 5 Accordingly, it includes at least a length equal to the sum of the widths of the second housing part. 7, which propagates in the y-direction according to FIG. 2B includes, as well as a required minimum penetration depth into the adjacent battery cell 2. The required minimum penetration depth results from the applied test parameters and can therefore preferably range from 10 to 90% of the cell thickness of the adjacent battery cell. 2 extend to several times the aforementioned cell thickness. The propulsion mechanism also includes... 6 Dimensions and components that are set up to hold the nail 5 to move in a stroke that corresponds at least to the required penetration depth.

[0021] According to the invention, the propagation test cell advantageously fulfills 3 not only the purpose, the propulsion mechanism 6 to carry out thermal penetration through dendrite formation in at least one adjacent battery cell 2 of a cell module 1 to initialize, but also includes physical properties that influence the consequences of the propagation of thermal runaway in the aforementioned adjacent battery cell. 2 on other surrounding battery cells 2 can be replicated. For this purpose, the first housing part can be used. 4 and the second housing part 7 Materials include the combination of which the propagation test cell 3 overall thermal and electrical conductivity of the other battery cells 2is perceptible. The physical target properties can include, in particular, thermal conductivity, heat capacity, electrical conductivity, and the modulus of elasticity, as well as other physical properties. Generally, the first housing part can 4 and second housing part 7 preferably comprising metals and metal compounds, plastics and special polymers, as well as fiber-reinforced composites as materials. In an advantageous embodiment, the first housing part comprises 4 and second housing part 7 Preferably materials that can be manufactured using extrusion processes such as 3D printing or rapid prototyping. In this way, the propagation test cell 3 It can be manufactured on-site and can be adapted at short notice to differing geometric and / or physical requirements. In an advantageous embodiment, the first housing part can be 4and / or the second housing part 7 They can be manufactured using metal 3D printing, especially aluminum printing. Generally, the first housing part can be... 4 and second housing part 7 Material pairings include those that possess the aforementioned physical properties of the entire propagation test cell 3 to replicate the requirements in a manner appropriate to the specifications. In an advantageous embodiment, the second housing part comprises 7 Materials that have electrically insulating properties to form the first housing part 4 the propagation test cell 3 and especially the nail 5 of the thrust mechanism 6 electrically compared to at least one adjacent battery cell 2 to isolate. This can be achieved, for example, by applying an additional film to at least the reference surfaces ( SB, SC ) opposite base surfaces of the two housing parts ( 4, 7). Additionally, a pairing consisting of a first housing part can be performed. 4 and a second housing part 7 comprising a mechanical and / or chemical or any other connection to couple the two aforementioned components. In one embodiment, the areal extent of the reference surface SC of the second housing part 7 at least larger than the area of ​​the opening relative to the reference surface SB of the first housing part 4, so that that opening through the reference surface SB of the first housing part 4 in contact with the second housing part 7 It is completely sealable, except for the through-hole. 8. Whereby the through-hole 8 before activation of the thrust mechanism 6The through-hole can initially be completely or partially open or closed, with the completely or partially closed state preferably being achieved by foiling or other sealing elements to seal against reaction gases. Alternatively, the through-hole can be 8 before activation of the thrust mechanism 6 be sealed by further elements, so that these can be activated by the thrust mechanism. 6 and / or is opened by piercing the nail through the corresponding closure.

[0022] In one embodiment, the dimensions of the outer shape of the propagation test cell include 3 in all spatial directions a multiple of the corresponding respective dimensions of the battery cell 2, with which the aforementioned propagation test cell 3 within a cell module 1can be arranged. In an advantageous embodiment, at least one dimension of the outer shape of the propagation test cell comprises 3, preferably the width, a multiple of the corresponding dimension of the battery cell 2, with which the propagation test cell 3 within a cell module 1 can be arranged, whereby the remaining dimensions of the propagation test cell 3 that battery cell 2 similar, so that the propagation test cell 3 with at least one additional battery cell 2 or a multiple thereof within a cell module 1 is substitutable. In a preferred embodiment, the aforementioned multiples of the spatial dimensions correspond to integer multiples, such that the propagation test cell according to the invention 3 integer multiples of the battery cells 2can replace. The lateral extent of the propagation test cell 3 corresponds to FIG. 2B the y-direction of the indicated Cartesian coordinate system ( x, y, z According to the invention, the propulsion mechanism is 6 the propagation test cell 3 set up to nail 5 in at least one adjacent battery cell 2 of a cell module 1 to introduce. Depending on the geometric design of the battery cells. 2 or the entire cell module 1 or the requirements of the propagation test to be performed, such as penetration or perforation, or in other words, the ratio of the necessary penetration depth of the nail 5 to the width expansion of the other battery cells 2, It may be necessary for the nail to 5 exhibits a minimum longitudinal extent that is greater than the simple lateral extent of one of the other battery cells 2is. For this special case, the first housing part can 4 include an increased width, so that the entire propagation test cell 3 a multiple of a neighboring battery cell 2 includes. In this advantageous way, multiple battery cells can be combined. 2 through the propagation test cell 3 can be substituted. According to this characteristic, the longitudinal extent of the nail can be determined. 5 According to the invention, advantageously comprising any dimension in relation to the rest of the test setup.

[0023] In an advantageous embodiment, the propagation test cell comprises 3 at least one temperature 10 and / or at least one pressure measuring point 11. By applying temperature- 10 and pressure measuring points 11 are the temperature profile and the mechanical stress of the propagation test cell 3and thus the load change in the entire cell module 1 during the propagation test and in the immediate vicinity of the short circuit fault. In an advantageous embodiment, in which the propagation test cell 3 multiple temperature 10 and / or pressure measuring points 11 The temperature profile and mechanical stress during the propagation test at several positions within the propagation test cell are arranged as follows: 3 measurable, whereby the physical effects of propagation to at least one neighboring battery cell 2 and can be mapped more accurately to the entire cell module. In one embodiment, the temperature- 10 and pressure measuring points 11 on the surfaces, especially on the reference surfaces ( SB, SC ) of the first and second housing parts ( 4, 7 ). arranged. In one embodiment in which the second housing part7 electrically insulating properties compared to at least one adjacent battery cell 2 exhibits the temperature- 10 and pressure measuring points 11 In this way, it is also electrically isolated from the other and simultaneously in close proximity to the surface of the neighboring battery cell. 2 arranged. In an alternative advantageous embodiment, the temperature- 10 and pressure measuring points 11 within the first housing part 4 and / or the second housing part 7 arranged. For this purpose, for example, further recesses can be made in the material of the two housing parts during manufacturing ( 4, 7 ) are provided. These recesses can still include a physical connection to the surfaces, so that the corresponding temperature- 10 and pressure measuring points 11can be arranged in the respective positions. The second housing part 7 This can also be achieved by adding corresponding bulges on the reference surface. SC include those which fit completely or partially into the associated recesses of the temperature- 10 and pressure measuring points 11 of the first housing part 4 protrude inwards so that the aforementioned measuring points are fixed and protected / insulated.

[0024] Furthermore, the invention includes a method for performing a propagation test on a cell module 1, comprising at least two battery cells 2, encompassing the substitution of at least one of the battery cells 2 with a propagation test cell according to the invention 3 in a first step S1. In an embodiment in which an application-specific propagation test is performed by bridging at least one cathode and one anode of a battery cell 2To initialize, a corresponding nail must be used. 5 at a required depth into the corresponding battery cell 2 penetrate, so that a single propagation test cell 3 the same dimensions as one of the other battery cells 2 having sufficient space for a propulsion mechanism according to the invention 6 in the first housing part 4 is present. Therefore, it is sufficient if exactly one battery cell is present. 2 through the propagation test cell according to the invention 3 is exchanged. In an embodiment in which, for the purpose of carrying out an application-specific propagation test, the complete penetration of a battery cell 2 If required, the propagation test cell according to the invention can 3 an integer multiple, but at least twice, of the width of the battery cell 2 include, so that the first housing part 4has sufficient space to accommodate a thrust mechanism according to the invention. 6 to be able to arrange, which is set up to have a correspondingly long nail required 5 to fix.

[0025] In a second step S2 The physical and electrical integration of the propagation test cell takes place. 3 within the cell module 1, these in the same way as the other battery cells 2 within the cell module 1 is positioned and fixed, whereby the propagation test cell 3 in the same way as the other battery cells 2 within the cell module 1 It can be electrically connected or bridged accordingly so that the battery circuit is not interrupted. In a further step S3 The networking of the temperature- 10 and pressure measuring points 11with the further test setup, wherein the electrical wiring of the aforementioned measuring points, which consist of one or more test interfaces 9 It can be guided and connected to measurement technology. In a further step S4 The preparation of the cell module takes place. 1, where the accumulator is electrically charged and / or its functionality is tested within the test setup. In a further step S5 The metrological acquisition of measurement parameters such as electrical voltage, temperature, pressure over time and other parameters which result from test parameters according to the application is initiated, and then in a final step S6 the initialization of the propagation test by actuating the propulsion mechanism 6 the propagation test cell 3 executed. Ausführungsbeispiele

[0026] The following are exemplary embodiments of the described designs. Further features and advantages are also shown in the supporting diagrams, which illustrate: FIG. 3A a mechanically activatable propagation test cell, FIG. 3B the exploded view of the mechanically activated propagation test cell, FIG. 4A the sectional view of the mechanically activatable propagation test cell, FIG. 4B the sectional view of the mechanically activated propagation test cell as well as FIG. 5A a pneumatically activated propagation test cell, FIG. 5B exploded view of a pneumatically activated propagation test cell, FIG. 6A the sectional view of the pneumatically activated propagation test cell, FIG. 6B The sectional view of the pneumatically activated propagation test cell.

[0027] In FIG. 3A und FIG. 3B is an exemplary embodiment of a propagation test cell 3with mechanically activated propulsion mechanism 12 illustrated. The first housing part 4 comprises an essentially cuboid shape, with the second housing part 7 the same area as its reference surface SC like the reference surface SB of the first housing part 4 includes the external dimensions of the entire propagation test cell. 3 similar to those of a single of other battery cells 2 of a cell module 1, in which the propagation test cell 3 therefore exactly instead of a single battery cell 2 replaceable, as in FIG. 1A indicated. The propulsion mechanism 6 includes a cuboid-shaped recess within the first housing part 4 with opening to the surface of the reference surface SB as well as a cylindrical mechanical connection to an end face, through which a test interface 9 is formed. The mechanical propulsion mechanism 12 The diagram shown here is merely an example and a schematic representation; the depicted mechanism is neither intended to be exhaustive nor to limit the possible designs. Thus, the mechanical propulsion mechanism is... 12 exemplified by the principle of the inclined plane, whereby a first slide is located within the recess of the thrust mechanism. 6 is mounted so that it can move in the x-direction and has a mechanical connection to a kind of connecting rod of the test interface 9 includes the test interface 9 This corresponds to a mechanical guide, called a connecting rod, which in this way is guided from outside the propagation test cell. 3 and the cell module 1It is movable. As a counterpart to the aforementioned first slider, another slider is arranged opposite it, which is mechanically connected to a nail guide adapter. 13 is coupled to which the nail 5 is arranged. In one embodiment, the nail guide adapter comprises 13 an electrically insulating material, so that the nail 5 of the other components of the mechanical thrust mechanism 12 as well as the propagation test cell 3 It is electrically insulated. The exact design of the mechanical propulsion mechanism. 12, The number, type and storage of its components as well as the type and design of all mechanical connections are not the subject of the invention, the purely schematic representation of the described mechanics being intended to clarify.

[0028] For receiving and guiding the nail 5 in its movement on the axis of movement MA The second housing part includes 7 a corresponding through-hole 8 as well as an additional nail guide fit 14, which are shown here in an exemplary manner as a reference surface SB of the second housing part 7 arranged hollow cylinder with its longitudinal axis aligned with the through-bore and the axis of movement MA is arranged. In an advantageous embodiment, the inner diameter of the through-hole of the nail guide fit comprises 14 a clearance fit that corresponds to the diameter of the nail shaft 5 corresponds, so that it passes through the nail guide fit 14 in its movement on the axis of movement MA is guided. In one embodiment, the second housing part can 7 and / or the nail guide fit 14 include an electrically insulating material to provide electrical insulation for the nail 5compared to the other components of the propagation test cell 3 to complete. Additionally, the second housing part includes 7 a foil covering an area at least equal to that of the adjacent battery cell 2 Contact surface of the second housing part 7 expands and has electrically insulating and sealing properties, so that when the nail penetrates 5 into the aforementioned battery cell 2 This is also sealed against the formation of reaction gases.

[0029] Activation of the mechanical propulsion mechanism 12 The propagation test is initiated by mechanical actuation of the indicated connecting rod via the test cell interface. 9,which here is merely designed as a mechanical guide for the aforementioned connecting rod, so that the first slider moves along the x-axis in the direction of the test cell interface 9 is pushed against the opposite end face. Corresponding to the movement of the first slider, the second slider, which is oriented in the opposite direction to the first slider, is moved in the y-direction, towards the second housing part. 7 shifted, causing the nail 5, which uses the nail guide adapter 13 is mechanically coupled to the second slider on the axis of movement MA is being moved.

[0030] In one embodiment, wherein the propulsion mechanism 6 a propagation test cell according to the invention 3 mechanically activatable as well as the test cell interface 9 merely as a mechanical guide for components of the mechanical thrust mechanism 12is trained, electrical connections can be subjected to temperature- 10 and pressure measuring points 11, which are located within the second housing part 7 are arranged, for example, at the test interface 9 opposite end face of the first housing part 4 and / or the second housing part 7 to be led outwards. According to the sectional view of a propagation test cell. 3 with mechanical propulsion mechanism 12 and an adjacent battery cell 2, according to FIG. 4A und FIG. 4B The described activation of the propulsion mechanism takes place. 6 by moving the connecting rod of the test cell interface 9 in the direction of the arrow, whereby the nail 5 due to the movement of the nail guide adapter 13 through the gas-sealed nail guide fit 14 of the second housing part 7 is guided and into the adjacent battery cell2 penetrates. When the nail penetrates 5 into the adjacent battery cell 2 Due to its longitudinal extension, it penetrates at least one layer of the anode. 15, the cathode 16 as well as the separator 17, according to the invention, thereby creating a short circuit between the anode 15 and cathode 16 the battery cell 2 The thermal runaway is triggered and the thermal runaway is initialized.

[0031] In FIG. 5A und FIG. 5B is an exemplary embodiment of a propagation test cell 3 with pneumatically activated propulsion mechanism 18 illustrated. The first housing part 4 comprises an essentially cuboid shape, with the second housing part 7 the same area as its reference surface SC like the reference surface SB of the first housing part 4includes the external dimensions of the entire propagation test cell. 3 similar to those of a single of other battery cells 2 of a cell module 1, in which the propagation test cell 3 therefore exactly instead of a single battery cell 2 replaceable, as in FIG. 1A indicated. The propulsion mechanism 6 includes a recess within the first housing part 4 with opening to the surface of the reference surface SB as well as a connection to an end face to which a test interface is attached. 9 connects. The pneumatic propulsion mechanism 18 The mechanism shown here is merely an example and schematic representation; it is neither intended to be exhaustive nor to limit the possible designs. For example, the pneumatic propulsion mechanism... 18exemplified by the principle of a pneumatic spring using a pressure diaphragm, wherein the recess of the propulsion mechanism 6 via the nail guide adapter 13 in the design of a pressure membrane and the recess for connection to the test cell interface 9 about the second part of the housing 7 It is sealed. Additional sealing elements can be used within the pneumatic thrust mechanism for this purpose. 18 as well as on the second housing part 7 be arranged. In one embodiment, the nail guide adapter comprises 13 an electrically insulating material, so that the nail 5 of the other components of the pneumatic thrust mechanism 18 as well as the propagation test cell 3 It is electrically insulated. The exact design of the pneumatic propulsion mechanism. 18,The number, type and storage of its construction and sealing elements, as well as the type and design of all supply devices relating to the pneumatic fluid, are not the subject of the invention, the purely schematic representation of the described mechanics being intended to clarify.

[0032] According to FIG. 6A The second housing part includes 7 for receiving and guiding the nail 5 in its movement on the axis of movement MA a corresponding through-hole 8 as well as an additional nail guide fit 14, which are shown here in an exemplary manner as a reference surface SB of the second housing part 7 arranged hollow cylinder with its longitudinal axis aligned with the through-bore and the axis of movement MA is arranged. In an advantageous embodiment, the inner diameter of the through-hole of the nail guide fit comprises14 a clearance fit that corresponds to the diameter of the nail shaft 5 corresponds to the gas-sealed nail guide fit. 14 in its movement on the axis of movement MA is guided. In one embodiment, the second housing part can 7 and / or the nail guide fit 14 to include an electrically insulating and pneumatically sealing material to provide electrical insulation for the nail 5 compared to the other components of the propagation test cell 3 as well as the sealing of the entire pneumatic thrust mechanism 18 to complete the further test setup.

[0033] According to FIG. 6B The pneumatic propulsion mechanism is then activated. 18 as well as the initialization of the propagation test by pneumatic actuation via the indicated test cell interface 9,which is designed here only as a pneumatic pipeline, so that the pneumatic fluid flows in the direction of the arrow into the cavity of the recess of the mechanical thrust mechanism 12 is inserted. This corresponds to the pressure build-up within the aforementioned cavity on the inside of the nail guide adapter, which is designed as a pressure membrane. 13 The corresponding pressure diaphragm is moved towards the second housing part. 7 extended, causing the nail 5, the one with the nail guide adapter 13 mechanically coupled, on the axis of movement MA is moved. When the nail penetrates 5 into the adjacent battery cell 2 Due to its longitudinal extension, it penetrates at least one layer of the anode. 15, the cathode 16 as well as the separator 17, according to the invention, thereby creating a short circuit between the anode 15 and cathode 16 the battery cell2 The thermal runaway is triggered and initiated. In one embodiment, wherein the thrust mechanism 6 a propagation test cell according to the invention 3 pneumatically activatable as well as the test cell interface 9 merely as a pneumatic pipeline of the pneumatic jacking mechanism 18 is trained, electrical connections can be subjected to temperature- 10 and pressure measuring points 11, which are located within the second housing part 7 are arranged, for example, at the test interface 9 opposite end face of the first housing part 4 and / or the second housing part 7 be led outwards.

[0034] The different operating modes of the propulsion mechanism 6 the propagation test cell according to the invention 3,These mechanisms, which can be activated hydraulically or pneumatically, mechanically, electrically or magnetically, or in other ways, are subject to application-specific advantages and disadvantages. For example, a mechanical propulsion mechanism... 12, This type of actuation, which can be implemented using principles such as an inclined plane, a mechanical spring, a gear or lever mechanism, or other methods, is characterized by its simple construction and electrical insulation achieved through the selection of suitable materials. However, it requires additional peripheral components to ensure external mechanical actuation. Hydraulic and pneumatic actuation systems, on the other hand, also have a simple design but require additional components and considerations for sealing the entire hydraulic or pneumatic propulsion mechanism. 18compared to the rest of the test setup and with regard to electrical insulation. Escaping fluids could, for example, affect the measurement results due to temperature- 10 and pressure measuring points 11 Impairing. Electrical and electromagnetic actuation methods, on the other hand, can effectively actuate the entire propulsion mechanism. 6 to ensure, although the introduction of further electrical peripherals could also have an impact on the overall propagation test.

[0035] Taking into account the relevant application, the propagation test cell according to the invention 3 However, it can be modularized in an advantageous way. For example, the different types of actuation can be adapted depending on the length of the nail. 5 are prefabricated as independent modules, which are connected by appropriately provided recesses in the two housing parts ( 4, 7), which can also be prefabricated in various standardized geometric dimensions and integrated into these. Alternatively, the first housing part can be used. 4 and second housing part 7 However, they can also be manufactured on-site at the respective test setup using the aforementioned extrusion manufacturing processes. In this way, the propagation test cell according to the invention can be produced. 3 according to the requirements of the respective propagation test procedure and the geometric dimensions of the cell module used. 1 as well as the corresponding battery cells 2, the required test parameters, such as the geometric design of the nail 5, necessary electrical insulation, the required penetration speed of the nail 5 or also the number, type and position of temperature- 10 and pressure measuring points 11 They can be adjusted. For example, pressure measuring points can be adjusted.11 In the design of strain gauges, they can also be subsequently attached to the surfaces of the first housing part. 4, of the second housing part 7 as well as the entire propagation test cell 3 They are arranged. In an alternative embodiment, pressure measuring points include 11 Strain gauges and / or piezoelectric measuring points. In a further alternative embodiment, temperature measuring points are included. 10 simple thermocouples. Bezugszeichenliste

[0036] 1 Cell module 2 Battery cell 3 Propagation test cell 4 first housing part 5 nail 6 Propulsion mechanism 7 second housing part 8 through hole 9 Test cell interface 10 Temperature measuring point 11 Pressure measuring point 12 mechanical propulsion mechanism 13 Nail guide adapter 14Nail guide fit 15 anode 16 cathode 17 separator 18 pneumatic propulsion mechanism B xyz Key points of the first housing part C xyz Key points of the second housing part MA axis of movement nail SB Reference surface of first housing part SC Reference surface of the second housing part

Claims

1. Propagation test cell (3), wherein - at least one individual of the battery cells (2) within a cell module (1) can be substituted by the propagation test cell (3), - a propagation test can be initialized from the inside via the propagation test cell (3), - the propagation test cell (3) comprises a mechanism (6) for inserting a nail (5) into an adjacent battery cell (2), wherein the propagation test can be initialized without external damage to the cell module (1).

2. Propagation test cell (3) according to claim 1, comprising • a first housing part (4) which has a cuboid external shape, comprising at least one drive mechanism (6) arranged completely or partially in the interior, which is configured to move the nail (5) along a movement axis (MA), • a nail (5) which is mechanically coupled to the drive mechanism (6) and arranged in such a way that its central axis of its longitudinal extent runs coaxially to the movement axis (MA), and • a second housing part (7), comprising a reference surface (SC) which is arranged parallel and oppositely directed to a reference surface (SB) of the first housing part (4) and is in contact with it, at least one passage which is completely or partially opened or closed and which is arranged coaxially to the movement axis (MA) of the nail (5) and has a passage cross-sectional area which is larger than the diameter of the shank of the nail (5).

3. Propagation test cell (3) according to claim 1 or 2, characterized in that the dimensions of the external shape of the propagation test cell (3) correspond to a multiple of the respective dimensions of a battery cell (2) with which the propagation test cell (3) can be arranged within a cell module (1).

4. Propagation test cell (3) according to claim 2 or 3, characterized in that the movement axis (MA) of the nail (5) corresponds to an orthogonal to the reference surface (SB) of the first housing part (4) and is arranged in such a way that the nail (5), in its movement along the said movement axis (MA), passes through the passage of the second housing part (7).

5. Propagation test cell (3) according to claim 2 to 4, characterized in that the nail (5) comprises a longitudinal extent which corresponds at least to the sum of the width of the second housing part (7) and a required penetration depth into at least one adjacent battery cell (2), wherein the advance mechanism (6) is configured to move the nail (5) in at least one stroke which corresponds to the required penetration depth.

6. Propagation test cell (3) according to claim 2 to 5, characterized in that the first housing part (4) and / or the second housing part (7) comprise at least one temperature measuring point (10) and / or pressure measuring point (11), wherein the said temperature measuring points (10) and / or pressure measuring points (11) are integrated into the two said housing parts (SB, SC) or are arranged on at least one surface of these.

7. Propagation test cell (3) according to claim 6, characterized in that the first housing part (4) and / or the second housing part (7) comprise at least one test interface (9) which is configured to establish a physical connection from the drive mechanism (6) and / or the temperature measuring points (10) and / or pressure measuring points (11) to the further environment of the propagation test cell (3).

8. Propagation test cell (3) according to claim 2 to 7, characterized in that the passage of the second housing part (7) comprises at least one passage bore (8) with a fit and / or that the second housing part (7) comprises at least one further guide element (14), wherein the passage bore (8) and the guide element (14) are configured to guide the nail (5) in its movement on the movement axis (MA) and / or to seal the propagation test cell (3) with respect to the at least one adjacent battery cell (2) against reaction gases.

9. Propagation test cell (3) according to claim 2 to 8, characterized in that the two housing parts (4, 7) comprise materials which are configured to simulate the propagation test cell (3) in the physical properties of thermal conductivity, heat capacity, electrical conductivity and modulus of elasticity to those of the further battery cells (2) of the cell module (1) in which the said propagation test cell (3) is used, in particular materials which can be processed by extrusion manufacturing processes, preferably 3D metal printing, and further materials which are configured to electrically insulate the propagation test cell (3) from the further said battery cells (2), in particular by means of a foiling on at least one outer surface of the two housing parts (4, 7) and / or a ceramic sheathing of the nail (5).

10. Method for carrying out a propagation test on a battery module (1), comprising at least two battery cells (2), characterized by the steps: • (S1) substituting at least one of the battery cells (2) with a propagation test cell (3) according to one of the preceding claims; • (S2) physical and electrical integration of the propagation test cell (3) within the cell module (1); • (S3) connection of the advance mechanism (6) and networking of temperature measuring points (10) and pressure measuring points (11) with the further test setup; • (S4) preparation of the cell module (1) by electrical charging of the accumulator and / or checking its operability within the test setup; • (S5) initiation of the metrological acquisition of measurement parameters such as voltage, temperature and / or pressure profiles and further; • (S6) initialization of the propagation test by actuating the advance mechanism (6) of the propagation test cell (3), wherein the said advance mechanism (6) thrusts a nail (5) into at least one adjacent battery cell (2), such that at least one anode and one cathode are penetrated, wherein an internal electrical short circuit is created in the said battery cell (2).

Images