GB2612088A

GB2612088A - Battery module

Info

Publication number: GB2612088A
Application number: GB2115144.4A
Authority: GB
Inventors: Roberts Ian; Balan Florin; Trigg Robert
Original assignee: Jaguar Land Rover Ltd
Current assignee: Jaguar Land Rover Ltd
Priority date: 2021-10-21
Filing date: 2021-10-21
Publication date: 2023-04-26
Also published as: WO2023066985A1; GB202115144D0

Abstract

Disclosed herein are examples of a housing (100) for a battery module (400) of an electric vehicle. The housing (100) comprises a first casing (102) comprising a first outer surface (102a) and a first inner surface (102b), the first inner surface forming a first channel having two first edges (106a, 106b) along opposite sides of the first channel; and a second casing (104) comprising a second outer surface (104a) and a second inner surface(104b), the second inner surface forming a second channel having two second edges (108a, 108b) along opposite sides of the second channel. The first and second casings (102, 104) are located together with each of the first edges (106a, 106b) meeting a corresponding second edge (108a, 108b) along their lengths. The first and second channels together form a space (110) for a battery. An inner lip (112) of the first edges is located in an inner recess (116) of the second edges. An outer lip (118) of the second edges is located in, and welded to, an outer recess (114) of the first edges. Having the first and second casings configured this way allows for a housing with variable height to be manufactured from common first and second housings.

Description

Battery Module

TECHNICAL FIELD

The present invention relates generally to a housing for a battery module. In particular, but not exclusively, the invention relates to a battery module housing for a vehicle traction battery, for example for a Battery Electric Vehicle (BEV). Aspects of the invention relate to housings, battery modules, battery packs, vehicles, and methods of forming a housing.

BACKGROUND

There has recently been increased interest in providing battery-powered vehicles, which has led to developments in vehicle batteries, in particular vehicle traction battery technology. It is generally desirable for vehicle batteries to provide high energy capacity and peak current output, whilst minimising the size and weight of the battery module and thus the vehicle.

Vehicle traction batteries often comprise one or more modules each containing a plurality of cells. It is generally desirable to package the cells into a battery module densely, so as to maximise the energy and current capacity that can be provided within a given packaging volume.

As well as aiming for desirable electrical properties and packaging space requirements, mechanical safety of the vehicle and battery is important to consider. The batteries of battery electric vehicles and similar may be designed to occupy a relatively large volume in the vehicle in order to provide as much electrical energy storage as possible. However, for safety reasons, the batteries may also be located in parts of the vehicle which are not designed to be "crumple zones" in the event of a crash, to help maintain battery integrity. Consequently, electric vehicle batteries may be located in the floor of the vehicle. Thus, there is a need to provide batteries in a way which allows them to be located in the floor of the vehicle, and therefore in a strong structural housing, while also mitigating against unwanted effects on the battery, such as weakening of electrical and/or mechanical connections to and within the battery, due to shocks, vibrations, and bumps etc. as the vehicle is driven/used.

It is an object of embodiments disclosed herein to at least mitigate one or more of the

problems of the prior art.

SUMMARY

According to an aspect of this disclosure, there is provided a housing for a battery module of an electric vehicle, the housing comprising: a first casing comprising a first outer surface and a first inner surface, the first inner surface forming a first channel having two first edges along opposite sides of the first channel, wherein the two first edges form a first pair of edges; a second casing comprising a second outer surface and a second inner surface, the second inner surface forming a second channel having two second edges along opposite sides of the second channel, wherein the two second edges form a second pair of edges; wherein the first and second casings are located together with each of the first edges of the first pair of edges meeting a corresponding second edge of the second pair of edges along the lengths of the corresponding first and second edges, and with the first and second channels together forming a space inside the housing in which a battery module is to be located; wherein the first edges each have an inner lip at the first inner surface and an outer recess at the first outer surface, and the second edges each have an outer lip at the second outer surface and an inner recess at the second inner surface, and wherein, in each set of corresponding first and second edges, the inner lip is located in the corresponding inner recess and the outer lip is located in the corresponding outer recess; and wherein the outer lip of each second edge is welded to the outer recess of the corresponding first edge, thereby welding together the first and second casings along each of the corresponding first and second edges.

Having the first and second casings configured to meet along the first and second edges in this way allows for a housing with variable height to be manufactured from common first and second casing parts. Thus, different battery clusters each having small differences in height may all be securely (i.e. tightly) housed in housings formed from common first and second casing parts. Allowing for a tight housing fit around a battery cluster helps improve structural stability of the battery module, and helps protect the cluster, using easily manufactured housing parts.

The outer lip of each second edge may be welded to the outer recess of the corresponding first edge by a fillet weld; for example a lap joint fillet weld.

The fillet weld may comprise a plurality of spatially separated fillet welds along the length of the outer lip of each second edge and the outer recess of the corresponding first edge. Such welding may provide sufficient structural stability to the battery housing while reducing the amount of localised heating caused by welding, by welding in a discontinuous pattern along the housing length.

The fillet weld may comprise a filler wire fillet weld; for example, a filler wire convex fillet weld. Adding filler wire may further strengthen the welding by providing structural support along the join between the first and second casings.

In the corresponding first and second edges, the outer lip may be located in a first portion of the corresponding outer recess, and at least a part of the remaining portion of the corresponding outer recess may be the location of the weld of the outer lip to the outer recess.

In each set of corresponding first and second edges, the inner lip may be located in a first portion of the corresponding inner recess, and at least part of the remaining portion of the corresponding inner recess may form part of the space in the housing.

The first and second channels may each have a length and a square C-shape cross section formed from a central panel and opposing side panels. The housing may further comprise a plurality of support beadings, each support beading located within the space along inner corners of the respective channels where each side panel and central panel meet, the support beadings configured to support a battery located in the space. The support beadings may be formed from adhesive, and/or curable material, such as a cured adhesive. Such support beadings may advantageously secure and support the battery cluster in the housing, aid electrical isolation of the battery cluster from the housing, and provide for some further variability in size of different battery clusters each supported in a housing made to a common

specification.

The support beadings may be located in the central portions of the inner corners, and may not located at end portions of the inner corners, along the length of the first and second channels.

The housing may be configured to receive an end cap at an end portion of the housing. The end portion of the housing may comprise a plurality of recessed screw holes configured to receive fixing screws to fix an end cap at the end portion of the housing and house the heads of the fixing screws within the plane of the outer surface of the housing.

The first and/or second casing may be formed of extruded aluminium.

The first and second inner surfaces may comprise an isolation sheet configured to electrically isolate busbars of a battery within the housing from the housing.

In a further aspect there is provided a battery module for an electric vehicle, the battery module comprising: any housing as disclosed herein; an end cap at an end portion of the housing; and a plurality of electrical cells electrically connected to the end cap, wherein the end cap is configured to be rigidly fixed to a structural component of a vehicle, thereby securing the battery module to the vehicle.

In a further aspect there is provided a battery pack comprising a plurality of electrically connected battery modules as disclosed herein.

In a further aspect there is provided a vehicle (e.g. an electrical vehicle or electrically-driven vehicle) comprising any housing disclosed herein, any battery module disclosed herein, or any battery pack disclosed herein.

In a further aspect there is provided a method of forming a housing for a traction battery of an electric vehicle, the method comprising: forming a first casing comprising a first outer surface and a first inner surface, the first inner surface forming a first channel having two first edges along opposite sides of the first channel, wherein the two first edges form a first pair of edges; forming a second casing comprising a second outer surface and a second inner surface, the second inner surface forming a second channel having two second edges along opposite sides of the second channel, wherein the two second edges form a second pair of edges; locating the first and second casings together with each of the first edges of the first pair of edges meeting a corresponding second edge of the second pair of edges along the lengths of the corresponding first and second edges, and with the first and second channels together forming a space inside the housing in which a battery module is to be located; wherein the first edges each have an inner lip at the first inner surface and an outer recess at the first outer surface, and the second edges each have an outer lip at the second outer surface and an inner recess at the second inner surface, and wherein, in each set of corresponding first and second edges, the inner lip is located in the corresponding inner recess and the outer lip is located in the corresponding outer recess; and welding the outer lip of each second edge to the outer recess of the corresponding first edge, thereby welding together the first and second casings along each of the corresponding first and second edges.

The first and second casings may be formed to have respective first and second channels each having a length and a square C-shape cross section of a central panel and opposing side panels. The method may then further comprise applying support beading material along inner corners of the first and second channels where each side panel and central panel meet, and curing the support beading material to form support beadings configured to support a battery located in the space.

Within the scope of this application it is expressly intended that the various aspects, embodiments, examples and alternatives set out in the preceding paragraphs, in the claims and/or in the following description and drawings, and in particular the individual features thereof, may be taken independently or in any combination. That is, all embodiments and/or features of any embodiment can be combined in any way and/or combination, unless such features are incompatible. The applicant reserves the right to change any originally filed claim or file any new claim accordingly, including the right to amend any originally filed claim to depend from and/or incorporate any feature of any other claim although not originally claimed in that manner.

BRIEF DESCRIPTION OF THE DRAWINGS

Embodiments will now be described by way of example only, with reference to the accompanying figures, in which: Figure la shows a welded housing according to examples of the present disclosure; Figure lb shows an exploded view of a housing, including inset views of first and second edges, according to examples of the present disclosure; Figure 1 c shows a portion of a welded housing showing the first and second edges, according to examples of the present disclosure; Figures ld and le show welding of the housing according to examples of the present disclosure; Figures 2a and 2b show a first casing having recessed screw holes according to

examples of the present disclosure;

Figure 3 shows an exploded view of a housing, including support beadings, according to examples of the present disclosure; Figure 4 shows an example battery module, according to examples of the present

disclosure;

Figure 5 shows a method of forming a housing for a battery according to examples of the present disclosure; and Figure 6 shows an example vehicle according to examples of the present disclosure.

DETAILED DESCRIPTION

Examples disclosed herein may aid in retaining batteries securely in vehicles while mitigating against unwanted structural weaknesses and/or electrical connection weaknesses, for example due to the vehicle receiving a shock or bump, and/or vibrations, for example, as it is used. An aim of examples disclosed herein is to contain a battery (e.g. battery cells) in a structurally rigid assembly. Some examples may mitigate against thermal propagation between battery modules of a battery pack comprising a plurality of modules located close to each other.

Figure la shows a welded housing 100, and figure lb shows an exploded view of a housing 100, including inset views A and B of first and second edges of the first casing portion 102 and second casing portion 104 of the housing. The housing 100 is suitable for a battery, for example, a battery module (e.g. a traction battery module) of an electric vehicle. An electric vehicle may be, for example, a battery electric vehicle (BEV), a hybrid electric vehicle (HEV) such as a mild hybrid electric vehicle (MHEV), or a plug-in hybrid electric vehicle (PHEV). A battery module may be considered to be any battery module of a vehicle, for example, a battery module which is used to start the engine. A traction battery module may be considered to be a module of a traction battery (or a traction battery per se) which is used to drive the vehicle (i.e. power the powertrain to propel the vehicle).

The housing 100 comprises a first casing 102 which is, as shown, an upper or top casing and a second casing 104 which is, as shown, a lower or bottom casing. The first casing 102 and/or the second casing 104 may be formed of extruded aluminium. A suitable material is aluminium 6063 with T6 temper, having an ultimate tensile strength of at least 190 MPa (23,000 psi) and yield strength of at least 160 MPa (23,000 psi). The housing 100 has a height dimension H and length L. The first casing 102 comprises a first outer surface 102a and a first inner surface 102b. The first inner surface 102b forms a first channel having two first edges 106a, 106b along opposite sides of the first channel. The two first edges 106a, 106b may be considered to form a first pair of edges 106a, 106b. The second casing 104 comprises a second outer surface 104a and a second inner surface 104b. The second inner surface 104b forms a second channel having two second edges 108a, 108b along opposite sides of the second channel, wherein the two second edges 108a, 108b may be considered to form a second pair of edges 108a, 108b.

The first casing 102 and the second casing 104 are located together, as shown in Figure la, with each of the first edges 106a, 106b of the first pair of edges meeting a corresponding second edge 108a, 108b of the second pair of edges along the lengths of the corresponding first and second edges (that is, looking end-on down the length L of the housing, the left edge 106a of the first casing 102 and the left edge 108a of the second casing 104 meet each other, and on the other side of the housing, the right edge 106b of the first casing 102 and the right edge 108b of the second casing 104 meet each other). In this way, the first and second channels together form a space 110 inside the housing 100 in which a plurality of electrical cells (which may be termed a "cluster") is to be located. The first and second casings 102, 104 are welded 120 together.

Inset A of Figure lb shows a first edge 106b of the pair of first edges 106a, 106b.

Each first edge 106a, 106b has an inner lip 112 at the first inner surface 102b and an outer recess 114 at the first outer surface 102a. Inset B of Figure lb shows a second edge 108b of the pair of second edges 108a, 108b. The second edges 108a, 108b each have an outer lip 118 at the second outer surface 104a and an inner recess 116 at the second inner surface 104b.

In each set 106a, 108a; 106b, 108b of corresponding first and second edges, when the first and second casings 102, 104 are located together, the inner lip 112 of the first casing 102 is located in the corresponding inner recess 116 of the second casing 104 and the outer lip 118 of the second casing 104 is located in the corresponding outer recess 114 of the first casing 102 as shown in Figures lc-le. The first and second casings 102, 104 of the housing 100 may be welded by laser welding or arc welding along the joining of each set 106a, 108a; 106b, 108b of corresponding first and second edges of the casings.

Figure lc shows a portion of a welded housing 100 showing the first and second edges, and Figures 1 d and le show examples of fillet welding of the housing. The outer lip 118 of each second edge is welded 120 to the outer recess 114 of the corresponding first edge, thereby welding together the first and second casings 102, 104 along each of the corresponding first and second edges.

As shown in Figures ld and 1 e, the outer lip 118 of each second edge may be welded 120 to the outer recess 114 of the corresponding first edge by a fillet weld 120. For example, the fillet weld may be a lap joint fillet weld, in which the flat inner and outer lips 112, 118 of the first and second edges are coplanar and overlap. Fillet welds may commonly be used to join two planar portions together in a "T" or perpendicular configuration by welding at the right angle (or both right angles) formed by the edge of one planar portion abutting a planar surface of a second planar portion in a "T" shape. However, in these examples, the two fillet welded planar portions (i.e. the first and second lips 112, 118) are parallel (coplanar), and the fillet weld 120 is located in a portion 114a of the outer recess 114 of the first edge 106a, 106b which is left unoccupied by material (specifically, left unoccupied by the outer lip 118 of the second edge 108a, 108b). Thus, the right angled surfaces in which the fillet weld 120 is located are the edge face 122 of the outer lip 118 of the second casing 104, and a wall portion 124 of the unoccupied portion 114a of the outer recess 114 of the first casing 102. The fillet weld 120 here may also be termed an edge weld.

Thus, of the corresponding first and second edges 106a-b, 108a-b, the outer lip 118 of the second casing 104 may be located in a first portion 114b of the corresponding outer recess 114 of the first casing 102, and at least a part of the remaining portion 114a of the corresponding outer recess 114 of the first casing 102 may be the location of the weld 120 of the outer lip 118 to the outer recess 114.

Thus, in each set of corresponding first and second edges 106a, 106b; 108a, 108b, the inner lip 112 may be located in a first portion 116b of the corresponding inner recess 116, and at least part of the remaining portion 116a of the corresponding inner recess 116 may form part of the space in the housing (i.e. it is within the housing, within the central space formed by the first and second channels being located together). By locating the first and second casings 102, 104 together so that their edges 120a, 120b; 104a, 104b, having inner and outer lips and recesses as discussed above, are located together and leaving an unoccupied space 114a, 116a which the lip 112, 118 does not occupy, there is some allowable variation in the height H in the housing when assembled. When the housing has a plurality of electrical cells (a "cluster") located within the housing, this variable height allowance provided by the edge profiles allowing for a tight fit of the housing around the cluster. In other words, the length of the recesses 114, 116 at the edges 106, 108 allows for the housing height H to be variable, to account for small variations in the heights of different clusters. In this way, plural first and second casings 102, 104 may all be manufactured to the same specification, and each pair of the first and second casings 102, 104 still allow for variations in cluster height for particular clusters, and provide a tight fit around the cluster located in the housing formed by the first and second casings 102, 104. This is advantageous as it allows for casings to be manufactured all to a common pattern without adhering to strict dimension tolerances in height, as the casings portions which are located together for welding allow for height adjustments depending on the particular cluster height located within, as well as allowing for a tight housing fit around the housed cluster to help structural stability and protection of the cluster and battery module overall.

The fillet weld 120 may comprise a filler wire fillet weld. For example, the welding 120 may comprise a filler wire convex fillet weld 120, as shown in Figure 1 e. This type of weld joint may advantageously provide increased structural stability to the housing, because the additional filler wire weld material used to provide the fillet weld forms a structural support to help prevent the welded joint breaking, for example as the housing vibrates or is bumped (e.g. while in use in a vehicle). Other weld types may be possible, for example, a laser weld, but such welds may not provide as high strength a weld as a fillet weld as they do not use additional weld material to form a "bridge" as a structural support between the casings 102, 104. Fillet welds, in particular filler wire fillet welds, may provide improved low fatigue cycle and high fatigue cycle behaviour.

As shown in Figure la, the welding 120 may comprise a plurality of spatially separated welds 120 along the length (as shown in Figures lc-le) of the housing; specifically, along the outer lip 118 of each second edge 108 and the outer recess 114 of the corresponding first edge 106. By providing a plurality of separate discrete welds 120, the heating effect of welding the casings 102, 104 together is lower in comparison to a single continuous weld being made across the length L of the housing, helping to reduce heat-induced distortion or warping of the casings 102, 104. The separate discrete welds may be spaced apart with unwelded portions 126 between the welds 120 in some examples, which may provide a strong enough weld joint between the casings 102, 104 while reducing the amount of welding material and time spent welding compared to an example in which welding is performed along substantially the while length L of the housing (even if this is performed in discrete welds, for example, by first welding a set of spatially separated welds 120 as shown in Figure la, and then going back along the length L of the housing to weld in the spaces 126 left between the first set of welds 120).

In examples in which a plurality of spatially separated welds 120 are used to fasten the casings 102, 104 together, a longer weld joint 120a (i.e. extending along the joint for a first distance) may be used towards the ends of the housing and a shorter weld joint or joints 120 (i.e. extending along the joint for a second distance shorter than the first distance) may be used towards the centre of the housing. Doing so may provide sufficient strength of welding of the casings 102, 104, in particular at the ends of the casings 102, 104 (and housing 100) which may be most likely portion of the housing to break apart, compared to the central portion of the housing. Still, discontinuous welding points are used, thereby reducing the amount of welding and weld material required to welding the casings 102, 104 together compared to a single continuous weld along the length L of the housing 100. The ends of the housing 100 may experience greater forces (e.g. lateral shear forces in the plane of the first and second edges 106, 108, or torsional forces on the housing 100) acting to pull the casings 102, 104 apart than the central portion of the housing).

Figure 2a shows a second casing 104, and Figure 2b shows a first and second casing 102, 104 together forming a housing 100, having recessed screw holes 202. Also shown are extended plate portions 204 extending along the length of the second casing 104 and from each end of the second casing 104, from each central plate portion 208 and a portion of each side portion 210 of the second casing 104, beyond the second pair of edges 108a, 108b. This extended plate portion 204 in effect leaves a space 212 at either side of the second casing 104. An end cap (not shown in Figure 2a) having at least one connection 214 (shown in Figure 2b) to the battery cells within the housing 100 may be located at either end of the housing 100 and in these examples, may be supported by the extended plate portion 208 while allowing the at least one connection 214 to be accessible from the sides of the housing where the spaces 212 are (and from the top of the housing as shown in Figure 2b as the first casing 102 has no extended plate portion).

Also shown in Figure 2a, the first and/or second inner surfaces 102b, 104b may comprise an isolation sheet 206 which is configured to electrically isolate busbars of battery cells (and/or other electrically conductive elements within the housing) from the housing 100.

The housing 100 may be configured to receive an end cap at an end portion 220 of the housing. The end portion 220 of the housing 100 may comprise a plurality of recessed screw holes 202 configured to receive fixing screws to fix an end cap at the end portion 220 of the housing 100 and house the heads of the fixing screws within the plane of the outer surface 102a, 104a of the housing 100 (i.e. within the recess). Locating the screw heads within the outer plane of the housing allows for battery modules to be located close to each other (which is desirable to make good use of the space available in the vehicle) while helping prevent thermal contact between the housings through screw heads which may otherwise be in contact with each other if they were protruding out from the outer plane 102a, 104a of the housing, rather than recessed in the space within the outer plane 102a, 104a of the housing.

Figure 3 shows an exploded view of a housing 100, including support beadings 300. Features in common with earlier described examples are not described again here. The first and second channels may be described as each having a length L and a square C-shape cross section formed from a central panel 308 and opposing side panels 310. The housing 100 in this example further comprises a plurality of support beadings 300, each support beading 300 located within the space along inner corners of the respective channels where each side panel 310 and central panel 308 meet. The support beadings 300 are configured to support a battery (i.e. a plurality of cells, or "cluster") located in the space. The support beadings 300 may be formed, for example, from resilient material (e.g. plastic or rubber), adhesive, curable material, or cured adhesive. A specific example of a suitable support beading material is Teroson (RTM) 9399 adhesive, which cures independently of air quality of humidity levels, is highly fungus resistant, and is resistant to UV aging and weathering, which is desirable for longer term use of the battery module. In respect of the battery module assembly process, this example support beading material has a high initial strength, and has a short tack-free time. This may aid in assembly of the battery cells in the housing, as the cells may be located in the housing shortly after applying the support beading material and the material may still support the cells, and finish curing with the cells in place, thereby providing a secure support which is partially moulded to the cells. Other support materials may also be used which may also exhibit one or more desirable properties as described.

The support beadings 300 help to keep battery cells housed within the housing 100 in position (i.e. without sliding along the housing 100 or rattling about in the housing 100; that is, they are tightly held in place within the housing 100). Further, the support beadings 300 may help to maintain the structural rigidity of the housing 100 and the battery module provided in part by the battery cells located in the housing 100.

The support beadings 300 may be located as shown in Figure 3 in the central portions 302 of the inner corners, and may not located at end portions 304 of the inner corners, along the length of the first and second channels. In this way the battery cells within the housing 100 may be securely supported without the support beadings obstructing location of end caps in the housing.

Figure 4 shows an example battery module 400 comprising a housing 100 as disclosed herein; an end cap 402 at an end portion of the housing 100; and a plurality of electrical cells (not visible, located within the housing) electrically connected to the end cap 402. The end cap 402 is configured to be rigidly fixed to a structural component of a vehicle, thereby securing the battery module to the vehicle. As described above, the end cap 402 is itself rigidly fixed to the housing 100 by way of the screws 404 having heads located in the recesses 202 of the housing 100.

Overall, a plurality of electrically connected battery modules (or in some examples, one battery module), may be called a battery pack.

The electrical cells may be secondary cells, i.e. rechargeable battery cells. In some examples the electrical cells may be capacitors, such as supercapacitors. In some examples a combination of rechargeable battery cells and capacitors may be used in a battery module. The term "electrical cell" may be used interchangeably with "cell" to mean an electrical energy storage element.

Figure 5 shows a method 500 of forming a housing for a battery according to examples of the present disclosure. The method 500 comprises forming a first casing 502. The first casing is formed to comprise a first outer surface and a first inner surface, so the first inner surface forms a first channel having two first edges along opposite sides of the first channel, wherein the two first edges form a first pair of edges. The method 500 comprises forming a second casing 504. The second casing is formed to comprise a second outer surface and a second inner surface, so the second inner surface forms a second channel having two second edges along opposite sides of the second channel, wherein the two second edges form a second pair of edges.

The method 500 comprises locating the first and second casings together 506 with each of the first edges of the first pair of edges meeting a corresponding second edge of the second pair of edges along the lengths of the corresponding first and second edges, and with the first and second channels together forming a space inside the housing in which a battery module is to be located. The first edges each have an inner lip at the first inner surface and an outer recess at the first outer surface, and the second edges each have an outer lip at the second outer surface and an inner recess at the second inner surface. In each set of corresponding first and second edges, the inner lip is located in the corresponding inner recess and the outer lip is located in the corresponding outer recess. The method 500 comprises welding 508 the outer lip of each second edge to the outer recess of the corresponding first edge, thereby welding together the first and second casings along each of the corresponding first and second edges.

It will be understood that the order of the operations shown in Figure 5 is not essential, and that in some embodiments the steps may be reordered, and/or some further steps may be included.

The first and second casings may be formed 502, 504 to have respective first and second channels each having a length and a square C-shape cross section of a central panel and opposing side panels. The method may then further comprise applying support beading material along inner corners of the first and second channels where each side panel and central panel meet, and curing the support beading material to form support beadings configured to support a battery located in the space. In some examples, the support beading material may be applied, and after partial curing of the material, a plurality of cells are located in the housing and on the partially-cured support beading material. The support beading material may then be completely cures, fixing the cells in place in the housing securely. The battery module 400 may be constructed in some examples by providing the first and second housings, applying the support beading material to the housings and partially curing it, locating the plurality of cells in the second housing on the beading material, locating the first casing together with the second casing, and welding them together with the cells within the housing space formed by locating the first and second housings together.

It will be appreciated that certain examples disclosed herein can be realised in the form of hardware, software or a combination of hardware and software; for example software to control a control system to perform at least a part of a method as discussed above e.g. in an automated or semi-automated process. Any such software may be stored in the form of volatile or non-volatile storage such as, for example, a storage device like a ROM, whether erasable or rewritable or not, or in the form of memory such as, for example, RAM, memory chips, device or integrated circuits or on an optically or magnetically readable medium such as, for example, a CD, DVD, magnetic disk or magnetic tape. Such software may comprise computer readable code stored on a non-transitory computer-readable storage medium. It will be appreciated that the storage devices and storage media are embodiments of machine-readable storage that are suitable for storing a program or programs that, when executed, implement embodiments disclosed herein. Accordingly, embodiments provide a program comprising code for implementing a system or method as claimed in any preceding claim and a machine readable storage storing such a program. Still further, embodiments disclosed herein may be conveyed electronically via any medium such as a communication signal carried over a wired or wireless connection and embodiments suitably encompass the same.

Figure 6 shows an example vehicle 600 comprising any housing 100 disclosed herein, any battery module 400 disclosed herein, or any battery pack disclosed herein.

All of the features disclosed in this specification (including any accompanying claims, abstract and drawings), and/or all of the steps of any method or process so disclosed, may be combined in any combination, except combinations where at least some of such features and/or steps are mutually exclusive.

Each feature disclosed in this specification (including any accompanying claims, abstract and drawings), may be replaced by alternative features serving the same, equivalent or similar purpose, unless expressly stated otherwise. Thus, unless expressly stated otherwise, each feature disclosed is one example only of a generic series of equivalent or similar features.

The invention is not restricted to the details of any foregoing embodiments. The invention extends to any novel one, or any novel combination, of the features disclosed in this specification (including any accompanying claims, abstract and drawings), or to any novel one, or any novel combination, of the steps of any method or process so disclosed. The claims should not be construed to cover merely the foregoing embodiments, but also any embodiments which fall within the scope of the claims.

Claims

CLAIMS1. A housing for a battery module of an electric vehicle, the housing comprising: a first casing comprising a first outer surface and a first inner surface, the first inner surface forming a first channel having two first edges along opposite sides of the first channel, wherein the two first edges form a first pair of edges; a second casing comprising a second outer surface and a second inner surface, the second inner surface forming a second channel having two second edges along opposite sides of the second channel, wherein the two second edges form a second pair of edges; wherein the first and second casings are located together with each of the first edges of the first pair of edges meeting a corresponding second edge of the second pair of edges along the lengths of the corresponding first and second edges, and with the first and second channels together forming a space inside the housing in which a battery module is to be located; wherein the first edges each have an inner lip at the first inner surface and an outer recess at the first outer surface, and the second edges each have an outer lip at the second outer surface and an inner recess at the second inner surface, and wherein, in each set of corresponding first and second edges, the inner lip is located in the corresponding inner recess and the outer lip is located in the corresponding outer recess; and wherein the outer lip of each second edge is welded to the outer recess of the corresponding first edge, thereby welding together the first and second casings along each of the corresponding first and second edges.
2. The housing of claim 1, wherein the outer lip of each second edge is welded to the outer recess of the corresponding first edge by a fillet weld.
3. The housing of claim 2, wherein the fillet weld comprises a plurality of spatially separated fillet welds along the length of the outer lip of each second edge and the outer recess of the corresponding first edge.
4. The housing of claim 2 or claim 3, wherein the fillet weld comprises a filler wire convex fillet weld.
5. The housing of any preceding claim, wherein, in the corresponding first and second edges, the outer lip is located in a first portion of the corresponding outer recess, and wherein at least a part of the remaining portion of the corresponding outer recess is the location of the weld of the outer lip to the outer recess.
6. The housing of any preceding claim, wherein, in each set of corresponding first and second edges, the inner lip is located in a first portion of the corresponding inner recess, and wherein at least part of the remaining portion of the corresponding inner recess forms part of the space in the housing.
7. The housing of any preceding claim, wherein the first and second channels each have a length and a square C-shape cross section formed from a central panel and opposing side panels.
8. The housing of claim 7, further comprising: a plurality of support beadings, each support beading located within the space along inner corners of the respective channels where each side panel and central panel meet; the support beadings configured to support a battery located in the space.
9. The housing of claim 8, wherein the support beadings are located in the central portions of the inner corners, and are not located at end portions, along the length of the first and second channels.
10. The housing of claim 8 or claim 9, wherein the support beadings are formed from a cured adhesive. 25
11. The housing of any preceding claim, configured to receive an end cap at an end portion of the housing; wherein the end portion of the housing comprises a plurality of recessed screw holes configured to receive fixing screws to fix an end cap at the end portion of the housing and house the heads of the fixing screws within the plane of the outer surface of the housing.
12. The housing of any preceding claim, wherein the first and second casings are formed of extruded aluminium.
13 The housing of any preceding claim, wherein the first and second inner surfaces comprise an isolation sheet configured to electrically isolate busbars of a battery within the housing from the housing.
14. A battery module for an electric vehicle, the battery module comprising: the housing of any preceding claim; an end cap at an end portion of the housing; and a plurality of electrical cells electrically connected to the end cap, wherein the end cap is configured to be rigidly fixed to a structural component of a vehicle, thereby securing the battery module to the vehicle.
15. A battery pack comprising a plurality of electrically connected battery modules of claim 14.
16. A vehicle comprising the housing of any of claims 1 to 13, the battery module of claim 14, or the battery pack of claim 15.
17. A method of forming a housing for a traction battery of an electric vehicle, the method comprising: forming a first casing comprising a first outer surface and a first inner surface, the first inner surface forming a first channel having two first edges along opposite sides of the first channel, wherein the two first edges form a first pair of edges; forming a second casing comprising a second outer surface and a second inner surface, the second inner surface forming a second channel having two second edges along opposite sides of the second channel, wherein the two second edges form a second pair of edges; locating the first and second casings together with each of the first edges of the first pair of edges meeting a corresponding second edge of the second pair of edges along the lengths of the corresponding first and second edges, and with the first and second channels together forming a space inside the housing in which a battery module is to be located; wherein the first edges each have an inner lip at the first inner surface and an outer recess at the first outer surface, and the second edges each have an outer lip at the second outer surface and an inner recess at the second inner surface, and wherein, in each set of corresponding first and second edges, the inner lip is located in the corresponding inner recess and the outer lip is located in the corresponding outer recess; and welding the outer lip of each second edge to the outer recess of the corresponding first edge, thereby welding together the first and second casings along each of the corresponding first and second edges.
18. The method of claim 17, wherein the first and second casings are formed to have respective first and second channels each having a length and a square C-shape cross section of a central panel and opposing side panels, the method further comprising: applying support beading material along inner corners of the first and second channels where each side panel and central panel meet, and curing the support beading material to form support beadings configured to support a battery located in the space.