Battery module or battery pack, comprising a plurality of cylindrical accumulators arranged in parallel to each other, assembled by fitting into a clamping flange supporting the busbars of the accumulator output terminals.

Abstract

Battery module or battery pack, comprising a plurality of cylindrical accumulators arranged in parallel to each other, assembled by fitting into a clamping flange supporting the busbars of the output terminals of the accumulators. The invention consists in producing a battery module whose accumulators are mechanically clamped and electrically connected by part of their height, advantageously at one of their longitudinal ends, by means of a single-piece assembly comprising a single rigid flange made of electrically insulating material on which is (are) fixed or integrally produced one (two) busbars for connecting the output terminals of the same polarity. Figure for the abstract: Fig. 7

Description

Title of the invention: Battery module or battery pack, comprising a plurality of cylindrical accumulators arranged in parallel to each other, assembled by fitting into a clamping flange supporting the busbars of the output terminals of the accumulators. Technical field

[0001] The present invention relates to the field of electrochemical accumulators, and more particularly to metal-ion accumulators.

[0002] The invention aims mainly to propose a reliable and easy solution for reversible mounting, i.e. which allows disassembly, of accumulators arranged within a module or a battery pack.

[0003] Although described with reference to a Lithium-ion accumulator, the invention applies to any metal-ion electrochemical accumulator, i.e. also sodium-ion, Magnesium-ion, Aluminum-ion accumulators, etc., or more generally to any electrochemical accumulator.

[0004] A battery module or pack according to the invention may be on-board or stationary. For example, the fields of electric and hybrid transport and grid-connected storage systems may be envisaged within the scope of the invention. Prior art

[0005] As illustrated schematically in Figures 1 and 2, a lithium-ion battery or accumulator usually comprises at least one electrochemical cell consisting of an electrolyte constituent 1 between a positive electrode or cathode 2 and a negative electrode or anode 3, a current collector 4 connected to the cathode 2, a current collector 5 connected to the anode 3 and finally, a packaging 6 arranged to contain the electrochemical cell with sealing while being crossed by a part of the current collectors 4, 5.

[0006] The architecture of conventional lithium-ion batteries comprises an anode, a cathode and an electrolyte. Several types of conventional architecture geometry are known:

[0007] - a cylindrical geometry as disclosed in the US patent application 2006 / 0121348,

[0008] - a prismatic geometry as disclosed in US patents 7348098, US 7338733;

[0009] - a stacking geometry as disclosed in US patent applications 2008 / 060189, US 2008 / 0057392, and US patent 7335448.

[0010] The electrolyte component 1 may be in solid, liquid or gel form. In the latter form, the component may comprise a polymer, ceramic or microporous composite separator soaked in organic or ionic liquid electrolyte(s) which allows the movement of the Lithium ion from the cathode to the anode for charging and vice versa for discharging, which generates the current. The electrolyte is generally a mixture of organic solvents, for example carbonates to which a lithium salt, typically LiPF6, is added.

[0011] The positive electrode or cathode 2 is made of Lithium cation insertion materials which are generally composite, such as LiFePO4, LiCoO2, LiNi0.33Mn0.33Co0.33O 2*

[0012] The negative electrode or anode 3 is very often made of graphite carbon or Li4TiO5O12 (titanate material), possibly also based on silicon or a composite formed from silicon.

[0013] The current collector 4 connected to the positive electrode is generally made of aluminum.

[0014] The current collector 5 connected to the negative electrode is generally made of copper, nickel-plated copper or aluminum.

[0015] A lithium-ion battery or accumulator can obviously comprise a plurality of electrochemical cells which are stacked on top of each other.

[0016] Traditionally, a Li-ion battery or accumulator uses a pair of materials at the anode and the cathode allowing it to operate at a high voltage level, typically equal to 3.6 Volts.

[0017] Depending on the type of application targeted, the aim is to produce either a thin and flexible lithium-ion accumulator or a rigid accumulator: the packaging is then either flexible or rigid and in the latter case constitutes a sort of case.

[0018] Flexible packaging is usually manufactured from a multi-layer composite material, consisting of a stack of aluminum layers covered by one or more polymer films laminated by bonding.

[0019] Rigid packaging is used when the intended applications are restrictive where a long service life is required, for example with much higher pressures to be supported and a stricter required level of sealing, typically less than 10 8mbar.l / s, or in environments with high constraints such as the aeronautical or space sector.

[0020] Also, to date, rigid packaging used consists of a metal case, typically made of stainless steel (316L stainless steel or 304 stainless steel) or aluminum (Al 1050 or Al 3003), or even titanium.

[0021] The geometry of most rigid Li-ion battery packaging cases is cylindrical, because most electrochemical cells in accumulators are wound by winding in a cylindrical geometry around a cylindrical mandrel. Prismatic case shapes have also already been produced by winding around a prismatic mandrel.

[0022] One of the types of rigid cylindrical shaped case, usually manufactured for a high capacity Li-ion accumulator, is illustrated in [Fig.3].

[0023] A rigid prismatic shaped case is also shown in [Fig.4].

[0024] The housing 6 comprises a cylindrical lateral envelope 7, a bottom 8 with a end, a cover 9 at the other end, the bottom 8 and the cover 9 being assembled to the casing 7. The cover 9 is generally crimped at a crimping groove 60. The cover 9 supports the current output poles or terminals 4, 5. One of the output terminals (poles), for example the negative terminal 5 is welded to the cover 9 while the other output terminal, for example the positive terminal 4, passes through the cover 9 with the interposition of a seal not shown which electrically insulates the positive terminal 4 from the cover.

[0025] Another possible configuration is that one of the output terminals (poles), for example the positive terminal 4, projects and passes through the cover 9 with the interposition of a seal not shown which electrically insulates the positive terminal 4 from the cover. In this configuration the positive terminal 4 projecting from the cover 9 defines a peripheral groove 90. The other output terminal, for example the negative terminal 5, is constituted by the bottom and therefore the lateral envelope of the housing 6 which is electrically connected.

[0026] This configuration illustrated in [Fig.5] is for example that which is typically encountered in existing accumulators of 18650, 21700 or 4680 format.

[0027] The widely manufactured rigid housing type also consists of a stamped cup and a cover, welded together on their periphery. On the other hand, current collectors include a bushing with a portion projecting from the top of the housing and which forms a terminal also called the exposed pole of the battery.

[0028] A battery pack P is made up of a variable number of accumulators which can reach several thousand which are electrically connected in series and / or in parallel with each other and generally by connection bars, usually called busbars.

[0029] An example of a battery pack P is shown in [Fig.6]. This pack consists of two modules M1, M2 of identical Li-ion accumulators A connected together in series, each module M1, M2 consisting of four rows of accumulators connected in parallel, each row consisting of a number equal to six Li-ion accumulators.

[0030] As shown, the mechanical and electrical connection between two Li-ion accumulators of the same row is made by screwing busbars B1, advantageously made of copper, each connecting a positive terminal 4 to a negative terminal 5. The connection between two rows of accumulators in parallel within the same module M1 or M2 is provided by a busbar B2, also advantageously made of copper. The connection between the two modules M1, M2 is provided by a busbar B3, also advantageously made of copper.

[0031] One of the current problems is to propose battery modules which allow the accumulators to be assembled and disassembled individually in a safe and rapid manner, both for maintenance and recycling reasons.

[0032] The possibility of being able to reuse all of the non-electrochemical components of a battery module and replace only one or other of the accumulators which constitute it makes it possible to guarantee a longer lifespan for the module than existing modules or battery packs.

[0033] In other words, being able to replace only the individual accumulators in a battery module as desired, quickly and securely, guarantees a real economic advantage for the end user.

[0034] Various solutions have been proposed for this purpose.

[0035] Patent application FR2920913A1 discloses a module with a cell separator compartment for separately housing the cylindrical accumulators of the module, which is arranged between two electrical contact panels each forming a busbar, and a screw system for fixing the whole. In the embodiment of [Fig. 12], the fixing of the contact strips is ensured by skewering on lugs with springs opposite each accumulator terminal. Although removable, the module according to this application is complex and time-consuming to assemble and disassemble, in particular due to the multitude of screws required, with in addition a significant volume and total mass of the module.

[0036] Patent US 10497912B2 proposes a system for holding cylindrical accumulators with two flanges to be screwed into each other and elastic tabs placed in the manner of a drawer. This solution suffers from the same drawbacks as that according to application FR2920913A1.

[0037] Patent application CN109037514A proposes a battery module whose cylindrical accumulators are indexed by two supports on either side, each integrated into a flange, the connections being made by the terminals at the ends of the accumulators. Here, the module comprises a very large number of parts which can make the assembly of the module complex and its disassembly long and tedious.

[0038] Utility model CN204243140U proposes a battery module with a support in the form of a parallelepiped frame in which the cylindrical accumulators are held and with busbars forming interconnections to the terminals at each end of an accumulator with an arrangement for series connection. support as disclosed necessarily adds mass and bulk and the interconnect busbars can be complex to produce.

[0039] Patent application US 2014 / 0234686 A1, comprising a battery module with cylindrical accumulators whose output terminals are arranged at both longitudinal ends, a heat sink formed of a thermally conductive material, a thermal interface arranged between one of the ends of the accumulators, and the heat sink, and an electrical interface point-bonded to the thermal interface. In this module, the thermal management of the module is achieved by means of additional elements, and the ease of assembly and disassembly are not actually demonstrated.

[0040] In summary, existing battery modules or battery packs are all complex, expensive and can have a significant volume and total mass. In addition, if they cannot offer disassembly, this is not in fact easy and quick and requires the use of tools such as unscrewing tools. Finally, thermal management is achieved by means of elements which do not simplify either assembly or disassembly.

[0041] There is therefore a need to improve solutions for integrating cylindrical format accumulators within a battery module or battery pack, in particular in order to ensure safe assembly of the accumulators without tools, while allowing easy disassembly and thermal management and without this affecting the weight and size to preserve the performance of the module or pack.

[0042] The aim of the invention is to meet at least part of this need. Statement of the invention

[0043] To do this, the invention relates, in one of its aspects, to a battery module comprising: - a plurality of electrochemical accumulators, each accumulator being rigidly packaged in the form of a case, arranged parallel to each other; - a single-piece mechanical clamping and electrical connection assembly comprising: • a rigid flange made of electrically insulating material, internally comprising a plurality of housings which each extend along a portion of the height of the flange and a plurality of mechanical accumulator clamping means, at least one of which is arranged in each housing; • at least one electrical connection plate forming a busbar, suitable for electrically connecting the output terminals of the same polarity of the accumulators to each other, the busbar extending parallel to one of the main faces of the rigid flange and comprising a plurality of tabs which extends into at least one of the housings of the rigid flange, preferably into each housing, to each form an electrical contact point with one of the output terminals of the same polarity of one of the accumulators, when part of the height of said accumulator is fitted into one of the housings and is clamped by the mechanical clamping means housed in said housing.

[0044] According to one configuration, each accumulator is of cylindrical format. The mechanical clamping is then preferably carried out with centering of each accumulator in one of the housings of the rigid flange.

[0045] According to an advantageous embodiment, the module comprises two busbars, one of which is adapted to electrically connect the positive output terminals of the accumulators to each other while the other is adapted to electrically connect the negative output terminals of the accumulators to each other.

[0046] According to this embodiment, and a first advantageous variant of the invention, one of the two busbars fits one of the two main faces of the flange while the other of the two busbars fits the other of the two main faces of the flange. Only the rigid flange acts as an electrical insulator between the two busbars.

[0047] According to this mode, and a second advantageous variant, the module comprises the following stack:

[0048] - one of the two busbars, fitting one of the two main faces of the flange,

[0049] - an intermediate plate made of electrically insulating material, fitting the busbar,

[0050] - the other of the busbars fitting the spacer plate. Although adding a piece electrical insulation, this second variant has the advantages of making the module even more compact, facilitating its manufacture by the possible lamination of the two busbars with the intermediate plate, and further increasing operational safety.

[0051] Each busbar is preferably fixed by gluing, in particular by point, by overmolding, gluing, snapping, on the rigid flange or where appropriate on the intermediate plate, or produced by additive manufacturing with the rigid flange or where appropriate with the intermediate plate.

[0052] According to another advantageous embodiment, the mechanical clamping means is an elastic compression means. An elastic compression means allows a dispersion of manufacturing tolerance to the diameter of the accumulator case, has good resistance to shocks and vibrations and ensures good guidance with centering and mechanical clamping of the accumulator.

[0053] Advantageously, it may be an O-ring mounted in a groove made in the housing, a tab or a blade, in particular a flexible one. A blade may also provide a clamping by mechanical friction. The tab may be di- directly manufactured within the flange, notably by additive printing.

[0054] According to an advantageous embodiment, each accumulator comprises a crimping groove in its cover in which the O-ring is elastically compressed to achieve mechanical clamping.

[0055] According to an advantageous structure, the output terminal of a polarity, in particular the negative polarity, of at least one of the accumulators is electrically connected to its housing, a tab of the connection busbar is flexible while being arranged towards the inside of one of the housings to form an electrical contact point against a part of the lateral envelope of said housing.

[0056] Preferably, a number of four flexible tabs are provided, preferably regularly angularly distributed, towards the housing, as electrical contact points with the lateral casing of the housing. This number of four contact points distributed, preferably regularly, allows redundancy and homogeneity of current circulation on the circumference of the lateral casing of the accumulator housing.

[0057] According to another advantageous structure, the output terminal of a polarity, in particular the positive polarity, of at least one of the accumulators projects at one of its longitudinal ends, a tab of the connection busbar is flexible while being arranged towards the inside of one of the housings to form an electrical contact point with the projecting terminal.

[0058] Preferably comprising a number of five flexible tabs distributed, preferably regularly angularly, at the periphery of the housing, as electrical contact points with the protruding output terminal. This number of five contact points distributed, preferably regularly, allows redundancy and homogeneity of current flow from the protruding accumulator output terminal.

[0059] According to an advantageous embodiment variant, the projecting output terminal defines a peripheral groove relative to the housing, the rigid flange comprises at least one rigid keying tab arranged in the housing so that its free end is housed in the peripheral groove to ensure keying. Thus, in the event of an attempt to mount an accumulator “upside down”, that is to say in the event of fitting its longitudinal end not including the projecting terminal, the keying tab(s) prevent(s) the electrical connection between the electrical contact points which extend inside the housing. With such keying, any risk of short circuit is prevented when mounting an accumulator in the single-piece assembly.

[0060] According to an advantageous module configuration, the module comprises a sealing plate arranged on one of the two busbars matching one of the two main faces of the flange so as to constitute with the mechanical clamping means a sealed zone. in the housing around the mechanically clamped accumulator part, in order to eject it from its housing by its degassing induced by its thermal runaway and thereby to electrically disconnect it from the module. With regard to the thermal runaway phenomenon, reference should be made to publication [1] and the protocol described in this publication. The so-called “self-heating” and “thermal runaway” temperatures are respectively noted Tl and T2 in this publication.

[0061] The temperature Tl, typically 70°C, in [Fig.2] of the publication, is the temperature from which the accumulator heats up without an external source at a typical rate of 0.02°C / min in adiabatic conditions.

[0062] The temperature T2, typically 150°C, in [Fig.2] of the publication, is the temperature from which the accumulator heats up at a typical heating rate of 10°C / min under adiabatic conditions, which leads to the melting of the separator in the electrochemical bundle of the accumulator, to a short circuit and therefore to the collapse of the voltage.

[0063] By "thermal runaway", we can thus understand here and within the framework of the invention, a ratio between the value of the derivative of the heating temperature and that of the time at least equal to 0.02°C per min.

[0064] Advantageously, the portion of the accumulator height fitted into one of the housings and clamped by the mechanical clamping means housed in said housing is less than 30%, preferably between 20 and 30% of the accumulator height.

[0065] Thus, the invention essentially consists of producing a battery module whose accumulators are mechanically clamped and electrically connected by part of their height, advantageously at one of their longitudinal ends, by means of a single-piece assembly comprising a single rigid flange made of electrically insulating material on which one (two) busbars for connecting the output terminals of the same polarity are fixed or integrally produced.

[0066] Ultimately, the invention provides numerous advantages, including: - efficient, secure, easy and quick assembly / disassembly without tools of each accumulator of a module or battery pack, by a simple mechanical action by fitting / unfitting said accumulator which holds it in or releases it from its housing in the flange. In other words, mechanical clamping / unclamping of each accumulator by a simple “push-pull” type action, with automatic centering and easy location, - an electrical connection of each accumulator simultaneously with its mounting in the flange which supports the two busbars of opposite polarity, - great compactness of a battery module with several cylindrical accumulators thanks to the single-block clamping and electrical connection assembly, - easily disconnectable power connectors (busbars), - the possibility of quickly and easily replacing a used accumulator, - the possibility of reusing non-electrochemical components of the battery module, thereby increasing its lifespan, - management of manufacturing tolerances of each accumulator by mounting by press-fitting - optimized and flexible thermal management in the non-fitted part of the single-piece mechanical clamping and electrical connection assembly, - the possibility of gathering and concentrating the power circuits for optimized electronic management of the module and limiting the lengths of electrical cable sections or busbars, - the possibility of performing mechanical clamping under tension of the accumulators.

[0067] For an application to a Li-ion module or battery pack, each accumulator is a Li-ion accumulator in which: - the negative electrode(s) material is chosen from the group comprising graphite, lithium, titanate oxide Li4TiO5Oi2; - the positive electrode(s) material is chosen from the group comprising LiFePO4, LiCoCK LiNi0.33Mn0.33Co0.33O2.

[0068] Other advantages and characteristics of the invention will become more apparent upon reading the detailed description of examples of implementation of the invention given by way of illustration and not limitation with reference to the following figures. Brief description of the drawings

[0069] [Fig.l] [Fig.l] is an exploded perspective schematic view showing the various elements of a lithium-ion accumulator.

[0070] [Fig.2] [Fig.2] is a front view showing a lithium-ion accumulator with its flexible packaging according to the state of the art.

[0071] [Fig.3] [Fig.3] is a perspective view of a state-of-the-art lithium-ion accumulator with its rigid packaging consisting of a cylindrical-shaped case.

[0072] [Fig.4] [Fig.4] is a perspective view of a state-of-the-art lithium-ion accumulator with its rigid packaging consisting of a prismatic-shaped case.

[0073] [Fig.5] [Fig.5] is a perspective view of a lithium-ion battery configuration according to the state of the art with its rigid packaging consisting of a cylindrical-shaped case with a projecting output terminal at one of its longitudinal ends, the other output terminal being constituted by the bottom of the case.

[0074] [Fig.6] [Fig.6] is a perspective view of a plurality of lithium-ion accumulators of cylindrical geometry according to the state of the art, grouped two battery modules electrically connected by means of electrical connection bars to form a battery pack.

[0075] [Fig.7] [Fig.7] is a perspective view of a battery module with a plurality of lithium-ion accumulators of cylindrical geometry according to the invention.

[0076] [Fig.8] [Fig.8] is a longitudinal sectional view of the module according to [Fig.7].

[0077] [Fig.8A] [Fig.8A] is a detail view of [Fig.8].

[0078] [Fig.9][Fig.10] Figures 9 and 10 are perspective views of busbars of positive and negative polarity respectively as they are installed in a single-piece assembly with a rigid flange according to the invention.

[0079] [Fig. 11] [Fig. 11] is a detailed view in longitudinal section showing an advantageous variant of the production of a rigid flange with keying tabs to ensure the keying of an accumulator during its fitting by fitting into a rigid flange.

[0080] [Fig. 12] [Fig. 12] repeats [Fig. 11] but illustrates an incorrect assembly of the accumulator with the keying tabs preventing its electrical connection to a busbar.

[0081] [Fig. 13] [Fig. 13] is a top view of the configuration according to [Fig. 11].

[0082] [Fig. 14] [Fig. 14] is a perspective view illustrating an alternative embodiment of a single-piece mechanical clamping and electrical connection assembly with the two busbars on one side of the rigid flange, separated from each other by an intermediate plate made of electrically insulating material.

[0083] [Fig. 15] [Fig. 15] is a longitudinal sectional view showing an alternative embodiment of a mechanical friction clamping means by means of a metal blade against the casing of an accumulator fitted into a housing of the rigid flange.

[0084] [Fig. 16] [Fig. 16] is a perspective view of a battery module according to the invention showing the possibility of mounting by fitting from above into the rigid flange.

[0085] [Fig. 17] [Fig. 17] is a detailed perspective view in longitudinal section illustrating an alternative embodiment defining a sealing zone between the accumulator and the single-piece assembly which allows self-ejection of the accumulator in the event of thermal runaway.

[0086] [Fig. 18] [Fig. 18] is a longitudinal sectional detail view illustrating the sealing area of [Fig. 17]. Detailed description

[0087] Figures 1 to 6 relate to different examples of Li-ion accumulators, flexible packaging and accumulator cases as well as a battery pack according to the state of the art.

[0088] These figures 1 to 6 have already been commented on in the preamble and are therefore not commented on further below.

[0089] For the sake of clarity, the same references designating the same elements according to the state of the art and according to the invention are used for all figures 1 to 18.

[0090] Throughout the application, a battery module is defined in a position relative to an orthogonal reference frame XYZ constituting a trihedron, comprising three axes perpendicular two by two, namely:

[0091] - an X axis, defining a transverse direction,

[0092] - a Y axis, defining a transverse direction, which with the X axis defines a plane XY,

[0093] - a Z axis, defining a longitudinal direction, perpendicular to the XY plane, and ending the general direction in which the accumulators extend.

[0094] Throughout the present application, the terms "lower", "upper", "bottom", "top", "below" and "above" are to be understood by reference to vertically arranged Li-ion battery cases.

[0095] Figures 7, 8 and 8A show an example of a module M of a Li-ion, Al, A2,...,A25 accumulator battery pack.

[0096] In the illustrated examples, the illustrated accumulators A1-A25 have cylindrical format cases 6, typically 18650 or 21700 format.

[0097] The accumulators A1-A25 are arranged parallel to each other. In the illustrated examples, the number of accumulators arranged parallel to each other is 25 but it goes without saying that a lower or higher number is suitable within the scope of the invention.

[0098] According to the invention, the module M comprises a single-piece assembly for mechanical clamping and electrical connection 10 of all the accumulators A1-A25.

[0099] This assembly comprises a rigid flange 11 made of electrically insulating material, of the PA 6.6, PEEK or HDPE type.

[0100] This rigid flange 10 in the general form of a right parallelepiped comprises two main faces 110, 111 parallel to each other and internally a plurality of housings 112 which each extend according to the height of the flange H, typically of the order of 15 mm for 18650 format accumulators.

[0101] In each housing 112 is arranged a mechanical accumulator clamping means in the form of an O-ring 14.

[0102] Two electrical connection plates 12, 13 each forming a busbar (12, 13) are fixed or made integrally with the rigid flange 11 to form the assembly monobloc.

[0103] Typically, one and / or the other of these busbars 12, 13 is made of aluminum, nickel-plated steel or copper.

[0104] Each of these two busbars 12, 13 is adapted to electrically connect the output terminals of the same polarity 4 or 5 of the accumulators to each other. In the example illustrated, the busbar 12 connects all the positive polarity terminals 4 of the accumulators A1-A25 which protrude through the cover of their case 6 while being electrically insulated from it.

[0105] The busbar 13 connects all the negative polarity terminals 5 of the accumulators A1-A25 which are constituted by the bottom of their case 6 and therefore to their lateral envelope of their case 6 which is electrically connected.

[0106] In the example illustrated in Figures 7 to 8A, the busbar 12 fits the main face 110 of the flange 11 while the busbar 13 fits the other of the two main faces 111 of the flange.

[0107] Each of the two busbars 12, 13 includes a connection tab 120, 130 for the electrical output, which projects outside the one-piece assembly. As shown, the two output connection tabs 120, 130 are parallel and project from the same side of the assembly 10. It is also possible to envisage one projecting on one side and the other on any other side of the assembly 10.

[0108] As illustrated in [Fig.9], the busbar 12 for connecting the positive output terminals 4 comprises, for each accumulator, a number of five flexible contact tabs 121, intended to be distributed regularly angularly at the periphery of a housing 112, as electrical contact points with the projecting output terminal. This number of five regularly distributed contact points 121 allows redundancy and homogeneity of current flow from the output terminal 4.

[0109] As illustrated in [Fig.10], the busbar 13 for connecting the negative output terminals 5 comprises, for each accumulator, a number of four flexible contact tabs 131, intended to be distributed regularly angularly in a housing 112, as electrical contact points with the lateral envelope of the housing 6. This number of four regularly distributed contact points 131 allows redundancy and homogeneity of current circulation on the circumference of the lateral envelope of the housing 6.

[0110] [Fig.8A] illustrates in detail the mechanical clamping and the electrical connections made between accumulators A1-A25 by the rigid flange 11 and the busbars 12, 13.

[0111] As shown in this [Fig.8A], a part of the height He of an accumulator is fitted into one of the housings 112 and this part of height and therefore the whole accumulator is clamped by the O-ring 14 housed in the housing 112 which is compressed both in a groove 113 of the flange in which it is mounted and the groove 60 crimping existing on A1-A25 accumulators.

[0112] The fitting and compression of the seal 14 are carried out so that, for each accumulator A1-A25, the positive output terminal 4 is in contact with all the tabs 121 of the busbar 12 and that the lateral casing of the housing 6 connected to the output terminal 5 on the bottom of the housing is in contact with all the tabs 131 of the busbar 13. Thus the electrical connections between all the positive output terminals 4 of the accumulators A1-A25 are electrically connected to each other by the busbar 12 and all the negative output terminals 5 are connected to each other by the busbar 13.

[0113] For each accumulator A1-A25, the compression of the seal 14 as well as the contact between the lateral casing of the housing 6 and the tabs 131 achieve the centering and mechanical clamping of the accumulator in the housing 112 of the rigid flange 11 in which it has been fitted by simple pushing action.

[0114] A simple disengagement by pulling the accumulator towards the outside of the flange 11 achieves the mechanical and electrical disconnection with the two busbars 12, 13.

[0115] An advantageous variant embodiment is shown in figures 11 to 13: it consists of a keying which avoids mounting an accumulator A1-A25 upside down, that is to say by reversing the direction of the output terminals 4, 5 to be electrically connected to the busbars 12, 13. According to this variant, the rigid flange 11 comprises at least one, preferably several rigid keying tabs 113 which are arranged in a housing 112 so that their free end is housed in the peripheral groove 90 of the positive output terminal 4 projecting relative to the housing 6. to guarantee the keying.

[0116] Thus, as shown in [Fig. 12], in the event of an attempt to mount an accumulator upside down, that is to say in the event of fitting by its bottom, its negative output terminal 5 constituted by the flat bottom of the casing 6 comes into direct contact with the free end of the keying tabs 114 and the height of the latter prevents any physical contact with the ends of the tabs 121, as shown diagrammatically by the dotted line, and therefore any electrical contact between the accumulator and the busbar 12. In other words, this keying prevents any risk of short circuit when mounting an accumulator A in the single-piece assembly 10.

[0117] [Fig. 13] illustrates an optimal nesting of each keying tab 114 between two adjacent electrical contact tabs 121.

[0118] An alternative configuration of the busbars 12, 13 relative to the rigid flange 11 is shown in Figures 14 and 15.

[0119] Here, a stack is formed by arranging an intermediate plate 15 made of electrically insulating material 15 between the two busbars 12, 13, a stack which is arranged on only one side of the flange 11 with the connection busbar 13 which fits one of the two main faces 110 or 111 of the flange 11. The electrical insulation between the two busbars 12, 13 and their electrical contact tabs 121, 131 is ensured by the thickness of the intermediate plate 15, made of epoxy or polyimide type material, preferably 300 μm thick.

[0120] The stacking 13, 15, 12 produced and its arrangement make it possible to make the module M even more compact, to facilitate its manufacture by the possible lamination of the two busbars 12, 13 with the intermediate plate 15, and to further increase operational safety.

[0121] [Fig. 15] also illustrates an alternative to the O-ring 14 housed in the crimping groove 60, as a mechanical clamping means: here, a flexible blade 140 arranged in a groove 115 provided for this purpose in the flange 11 allows clamping by mechanical friction. Mechanical clamping by friction can facilitate the mounting of the accumulators in the flange 11 which can be placed on a support, the accumulators A1-A25 then being fitted individually or collectively from above, either manually or using an automatic machine, as shown in [Fig. 16].

[0122] Another advantageous embodiment variant is illustrated in Figures 17 and 18. A sealing plate 16 can be arranged on the busbar top 12, matching one of the two main faces 110 or 111 by co-lamination for example. The materials can be of the Nomex type with a thickness of 500 μm co-laminated with an epoxy with a thickness of 1 mm for example.

[0123] Thus, this sealing plate 16 forms with the O-ring 14 a sealed zone Z in the housing 112 around the part of an accumulator A which is mechanically clamped there. In this way, in the event of thermal runaway of the accumulator A, the generated gases which will escape from the housing 6 according to the arrows at the top of [Fig. 17] will induce an overpressure between the plate 16 and the accumulator A due to the sealed zone Z. This overpressure will induce a force on the accumulator in the direction of its at least partial disengagement from the housing 112, as according to the arrow at the bottom of [Fig. 17] and thus eject the accumulator A from its housing 112. This thus causes the electrical disconnection of the accumulator A at least from the busbar 12 and therefore from the module M. In other words, the sealing plate 16 which defines the sealed zone Z allows electrical self-disconnection or even self-ejection of an accumulator in thermal runaway by its induced degassing.

[0124] The invention is not limited to the examples which have just been described; it is possible in particular to combine characteristics of the examples illustrated within non-illustrated variants.

[0125] Other variants and improvements may be envisaged without departing from the scope of the invention.

[0126] If in the illustrated examples, the output terminal 4 protrudes at one long end tudinal of a battery case 6 is the positive terminal and the output terminal 5 constituted by a case bottom 6 is the negative terminal, the invention can obviously be implemented with reversed terminals, i.e. terminal 4 as the negative terminal and terminal 5 as the positive terminal.

[0127] Other mechanical clamping means and arrangements can be envisaged within the rigid flange 11 of the single-piece assembly 10.

[0128] If in the illustrated examples, the housing 6 is cylindrical in shape, a prismatic shape can be envisaged. List of cited references:

[0129] [1]: Xuning Feng, et al. “Thermal runaway mechanism of lithium-ion battery for electric vehicles: A review”, Energy Storage Materials, Volume 10, January 2018, Pages 246-267.

Claims

Claims

1. Battery module (M) comprising: - a plurality of electrochemical accumulators (A1, A2...A30), each accumulator being rigidly packaged in the form of a case (6), arranged parallel to each other; - a single-piece mechanical clamping and electrical connection assembly (10) comprising: • a rigid flange (11) made of electrically insulating material, internally comprising a plurality of housings (112) which each extend along the height of the flange and a plurality of means (14, 140) for mechanically clamping the accumulator, at least one of which is arranged in each housing; • two electrical connection plates each forming a busbar (12, 13), adapted to electrically connect the output terminals of the same polarity (4 or 5) of the accumulators to each other, one of the busbars being adapted to electrically connect the positive output terminals of the accumulators to each other while the other of the busbars is adapted to electrically connect the negative output terminals of the accumulators to each other, the busbars each extending parallel to one of the main faces (110) of the rigid flange and comprising a plurality of tabs (121, 131) which extends into at least one of the housings, preferably into each housing of the rigid flange to each form an electrical contact point with one of the output terminals of the same polarity (4 or 5) of one of the accumulators,when a part of the height (He) of said accumulator is fitted into one of the housings and is clamped by the mechanical clamping means housed in said housing, the output terminal of a polarity (5), in particular the negative polarity, of at least one of the accumulators being electrically connected to its housing (6), a tab (131) of a connection busbar (13) being flexible while being arranged towards the inside of one of the housings (112) to form an electrical contact point against a part of the lateral casing of said housing, the electrical connection of each accumulator, being simultaneous with its mounting in the flange which supports the two busbars of opposite polarity, a disengagement by simple action of pulling the accumulator towards the outside of the flange (11) achieving the mechanical and electrical disconnection with the two busbars (12, 13).

2. Battery module according to claim 1, each accumulator being of cylindrical format.

3. Battery module according to claim 1 or 2, one of the two busbars (12) matching one of the two main faces (110) of the flange while the other of the two busbars (13) matches the other of the two main faces (111) of the flange.

4. Battery module according to claim 1 or 2, comprising the following stack: - one of the two busbars (13), matching one of the two main faces (110) of the flange, - an intermediate plate (15) made of electrically insulating material, matching the busbar - the other of the busbars (12) matching the intermediate plate.

5. Battery module according to one of the preceding claims, each busbar being preferably fixed by gluing, in particular by point, by overmolding, gluing, snapping, on the rigid flange or where appropriate on the intermediate plate, or produced by additive manufacturing with the rigid flange or where appropriate with the intermediate plate.

6. Battery module according to one of the preceding claims, the mechanical clamping means being an elastic compression means.

7. Battery module according to claim 6, the elastic compression means being an O-ring (14) mounted in a groove made in the housing or a tab or blade, in particular flexible (140).

8. Battery module according to claim 7, each accumulator comprising a crimping groove (60) of its cover in which the O-ring (14) is elastically compressed to achieve mechanical clamping.

9. Battery module according to one of the preceding claims, comprising a number of four flexible tabs (131) distributed, preferably regularly angularly, towards the housing, as points of electrical contact with the lateral casing of the housing.

10. Battery module according to one of the preceding claims, the output terminal of a polarity (4), in particular the positive polarity, of at least one of the accumulators projecting at one of its longitudinal ends, a tab (121) of the connection busbar (12) being flexible while being arranged towards the inside of one of the housings to form an electrical contact point with the projecting terminal.

11. Battery module according to claim 10, comprising a number of five flexible tabs (121) distributed, preferably regularly angularly, at the periphery of the housing, as electrical contact points with the projecting output terminal.

12. Battery module according to claim 10 or 11, the projecting output terminal defining a peripheral groove (90) relative to the housing, the rigid flange comprising at least one rigid keying tab (113) arranged in the housing, so that its free end is housed in the peripheral groove to guarantee keying.

13. Battery module according to one of the preceding claims, comprising a sealing plate (16) arranged on one of the two busbars matching one of the two main faces of the flange so as to constitute with the mechanical clamping means a sealed zone (Z) in the housing (112) around the mechanically clamped accumulator part in order to eject the latter from its housing by its degassing induced by its thermal runaway and thereby to electrically disconnect it from the module.

14. Battery module according to one of the preceding claims, the part of the accumulator height fitted into one of the housings and clamped by the mechanical clamping means housed in said housing being less than 30%, this preferably being between 20 and 30% of the accumulator height.

15. Battery module according to one of the preceding claims, each accumulator being a Li-ion accumulator in which: - the negative electrode(s) material is chosen from the group comprising graphite, lithium, titanate oxide Li4TiO5Oi2; the positive electrode(s) material is chosen from the group comprising LiFePO4, LiCoO2, LiNi0.33Mn0.33Co0.33O2.

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