GB2616842A

GB2616842A - Battery and monocoque vehicle

Info

Publication number: GB2616842A
Application number: GB2203825.1A
Authority: GB
Inventors: William Moffat John
Original assignee: Structural Battery Co Ltd
Current assignee: Structural Battery Co Ltd
Priority date: 2022-03-18
Filing date: 2022-03-18
Publication date: 2023-09-27
Anticipated expiration: 2042-03-18
Also published as: GB202203825D0; GB2617437A; GB2616842B; GB202301156D0

Abstract

The present invention relates to vehicle comprising a body having first and second layers that form at least part of a monocoque structure; a battery comprising cylindrical cells held together by a bonding material in a hexagonal pattern in the same plane, bonding a surface of a cell to an adjacent surface of an adjacent cell with triangular gaps between the cells, wherein the battery is located between the first and second layers; and connecting means for mechanically fixing the battery to the first and second layers. The cylindrical cells can be held within a cuboidal container that is fixed to the vehicle body by epoxy resin and/or reinforcing fiber, or by a surrounding flange that is rigidly fixed e.g. glued, welded, bolted or riveted, to the vehicle body. One of the first and second layers can be an outer skin of the vehicle. Preferably, the battery has a positive and negative terminal wherein the negative terminal is electrically connected to the outer skin. The vehicle can be an automobile, motorbike, scooter, e-mobility platform, watercraft, submarine, eVTOL helicopter or aircraft. A method of manufacturing a vehicle comprising said battery is also described.

Description

Battery and Monocoque Vehicle

Technical Field

[0001] The present disclosure relates generally to electric batteries, and more particularly, to structures of electric batteries, methods of manufacturing said structures, and how these electric batteries may serve structural purposes.

Introduction

[0002] Electric vehicles are becoming more commonplace and accessible in daily life, particularly electric cars, and even within motorsports.

[0003] Most powered vehicles were developed and designed with an internal combustion engine (ICE) to provide power to the vehicle for the purpose of transportation. This holds true for automobiles, aircrafts, and watercrafts. Of course, a battery was also employed within such vehicles to provide power for auxiliary purposes.

[0004] The typical design of an electric vehicle has two approaches: 1) simply replace the ICE internals with electric equivalents. This may mean replacing the ICE and fuel tanks with batteries, transformers, electric motors, and the like. It is also typical to keep the design of electric vehicles, specifically electric cars, as similar to the ICE version as possible. 2) use an electric vehicle skateboard and place the coachwork on the skateboard. This is a similar approach to the use of the ladder chassis seen with Land Rovers etc [0005] There is need to minimize the weight of a vehicle without compromising strength and rigidity. Batteries add considerably to weight. Extra weight typically necessitates additional body or chassis reinforcement, which further adds to weight. Batteries also take up more space than corresponding engine and fuel tank components in an ICE vehicle, which in turn means a larger, heavier vehicle or less passenger and luggage/payload space.

[0006] There is a need for an improved design for vehicle batteries and ways of installing them in a vehicle.

Summary of the Invention

[0007] A structural sandwich panel battery is provided that comprises cylindrical cells held together by a bonding material in a hexagonal pattern in the same plane, bonding a surface of a cell to an adjacent surface of an adjacent cell with triangular gaps between the cells for fluid flow in an axial direction between the cells.

[0008] The cylindrical cells are preferably, but not essentially oriented in the same polarization.

[0009] The sandwich panel layers are used mechanically for strength and stiffness and electrically to evacuate the energy.

[0010] A vehicle is also provided comprising: a body having first and second layers that form at least part of a monocoque structure; a battery as described and claimed, located between the first and second layers and connecting means for mechanically fixing the battery to the first and second layers.

[0011] The vehicle may be an automobile, motorbike, scooter, e-mobility platform, watercraft, submarine, eVTOL, helicopter or aircraft.

[0012] The cells of the battery may be aligned perpendicular to the first and second layers or parallel thereto. Both arrangements are described herein.

[0013] The battery is preferably fixedly connected to the both first and second layers.

[0014] In this way, the battery imparts rigidity to the vehicle. It provides strength and rigidity to the monocoque structure. By virtue of the triangular gaps or voids between the cells, the overall rigidity is increased without unnecessarily adding to weight. The batteries add no more weigh that is necessary to provide the ampere hours and voltage needed for the particular vehicle, but in the new arrangement, they add to the structural rigidity of the vehicle. In other words, they allow for weight saving by replacing other components that would otherwise be required for structural purposes.

[0015] Alternatively, the advantage of the arrangement can be viewed as minimizing space required to provide batteries for a monocoque vehicle.

[0016] The cylindrical cells may be held within a cuboidal container that is mechanically fixed to the vehicle body (e.g. by epoxy resin and/or reinforcing fiber or by a suitable surrounding flange that is glued/welded/bolted or otherwise rigidly fixed to the vehicle body.

[0017] The battery may perform the function of an elongate beam structure.

Brief description of the drawings

[0018] Fig. 1 illustrates part of a vehicle including a monocoque and a frame.

[0019] Fig. 2 further illustrates the monocoque of Fig. 1 in exploded view.

[0020] Fig. 3 illustrates a redesigned rear bulkhead that is an alternative to that of Figs. land 2.

[0021] Fig. 4 illustrates a cross sectional view of the rear bulkhead [0022] Fig. 5 illustrates an exploded view of a battery formed from a plurality of cylindrical cells.

[0023] Fig. 6 illustrates a top down view of the battery, with bonding material along lines of contact between adjacent cells.

[0024] Fig. 7 illustrates a side on view of the battery [0025] Fig. 8 illustrates a top down view of the battery in an arrangement alternative to that of Fig. 6.

[0026] Fig. 9 illustrates a cross section of a boat, showing spaces where a battery may be positioned.

[0027] Fig. 10 illustrates a cross section of an aircraft wing, showing a battery in position.

[0028] Fig. 11 illustrates a cross section of an aircraft cabin, with various batteries.

[0029] Fig 12 illustrates the internal construction of a cell of Fig. 5 [0030] Fig 13 illustrates a group of cells in a "horizontal" orientation between two layers.

Detailed description

[0031] Figure 1 illustrates an example body of a vehicle including a monocoque structure 100, rear bulkhead 110, and a frame 120 which may be referred to as a subframe or spaceframe. In particular, the rear bulkhead 110 serves as an interface between the monocoque 100 and frame 120 in that the bulkhead is connected to the monocoque or integrally formed with the monocoque and the frame is connected (e.g. bolted) to the bulkhead. Other arrangements can be envisaged that are entirely monocoque and have no frame. The monocoque is formed from composite material such as carbon fiber reinforced resin (e.g. carbon fiber but alternatively glass fiber).

[0032] Figure 2 shows that the monocoque 100 comprises a rear part 200 and a front part 220. Inside the rear part 200 is a fuel tank 210. The front part 220 has side parts 230 and 240 extending along the left and right sides of the vehicle. Each side part is a sandwich panel constructed of inner and outer layers, with filler material there between, such as a lightweight foam or honeycomb material. For example, left side part 230 has an outer layer 250 which forms the skin of the vehicle and an inner layer 260. Such a two-layer structure provided rigidity to the monocoque. The layers are integrally formed from the same fiber reinforced material, and the two-layer structure provides rigidity against bending and shearing as well as protection against compression forces that might cause the panels to buckle.

[0033] The rear bulkhead 200 encloses and protects the fuel tank 210. The rear bulkhead 200 provides structural support against bending (in x, y and 7 directions) and against shear. The rear bulkhead 200 has front and rear (fore and aft) layers 270, 280, which are connected by left and right side panels 290. Together, these give the bulkhead rigidity to protect the fuel tank 210.

[0034] Referring to Figures 3 and Figure 4, in particular the hollow space 410 or solid space 420 would be areas of interest for containing batteries contributing to the overall rigidity and structural integrity of the Eagle Plate 300 [0035] Figure 5 displays a plurality of cylindrical cells 530, in an exploded view, arranged in a hexagonal pattern, with bus bars 510, 560, and insulation 500, 520, 550, 570 vertically above and below. Insulation 520 is formed of a continuous web of circular discs, each with a central hole. Insulator 550 is similar but optional. Each cylindrical cell 530 has a positive terminal 531 at one end, nominally the top, and the rest of the body

S

(including the opposite end to the positive terminal 531, nominally the bottom) is a metal cylinder with no external insulation and therefore acts as a negative terminal 532. The cylindrical cell 530 has a built-in insulator 533 to separate the upper negatively charged rim/shoulder of the cell 532 from the positive 'button top' terminal 531 [0036] Each of the positive terminals 531 of the cylindrical cells 530 has an upwardly protruding 'button top' (shown in Fig. 12) that is internally insulated from the rim of the respective cell and is externally insulated by insulation 520 from directly touching the positive terminal bus bar 510. This latter insulation 520 is to prevent the bus bar having direct contact with any cylindrical cell 530. Insulation 520 also prevents the possibility that a positive terminal 531 of one cylindrical cell 530 may touch the negative terminal 532 of a neighboring cylindrical cell 530 due to misalignment.

[0037] The positive terminal bus bar 510 connects to each positive terminal 531 via a respective fuse 515 that goes through the respective hole in insulation 520. This fuse 515 ensures that any fault of a cylindrical cell 530 becomes isolated and does not affect any other cylindrical cells 530 or any surrounding system connected to the battery.

[0038] The negative terminal 532 may be connected through an insulation layer 550 to a negative terminal bus bar 560. The insulation layer 550 may also not be present, in which case the negative terminal 532 is directly connected to a negative terminal bus bar 560. The insulation layer 550 is presented for symmetry purposes in ease of manufacturing a plurality of batteries in opposing orientations.

[0039] The positive terminal bus bar 510 and negative terminal bus bar 560 have insulating caps 500 and 570 respectively. These serve the purpose of electrically insulating the bus bars 510 and 560 from any surrounding system or structure. In the case of the negative terminal bus bar, the cap is optional, as it is often the case that the negative terminal is grounded direct to an external skin of a vehicle.

[0040] The arrangement of cylindrical cells shown in Figure 5 forms a battery or can form several batteries with suitable connectors to connect them in series. This arrangement could also be extended in any radial direction with respect to the cylindrical cells 530.

[0041] Insulation layer 550, if present, allows for a simple busbar construction in the case of serially connecting groups of cells. It maintains symmetry top and bottom of the cell so that the same construction extends across cells that are to be connected in series. Where insulation 550 is present, alternative connections are required to connect the negative ends of the cells to the lower busbar, similar to the connections used to connect the positive terminals.

[0042] Figure 6 illustrates a top down view of cylindrical cells 600 joined with a bonding material 610 along the line of contact where cylindrical cells would touch when arranged in a hexagonal pattern in a same plane. Seven of the cells in a hexagon pattern are shown cross-hatched for example and further explanation. Four rows of cells are shown, but there may be more or fewer.

[0043] The bonding material between the cells can be electrically conductive, but is preferably non-conductive. It is structural, in the sense that it adds rigidity to the overall structure. It is preferably epoxy resin [0044] Every three neighboring cells 600 create a triangular gap 630 between them.

Broadly speaking the shape of the gap 630 is a hyperbolic triangle, as this triangular gap 630 is between three curved surfaces, but bonding material would be found at each vertex of the triangular gap 630.

[0045] This triangular gap 630 provides for a lightweight structure as will be described.

It can also facilitate the expansion of the cells when charging together with the circulation of coolant around the cells 600, and consequently around the entire battery. The coolant may be air that is allowed to flow by convection or by forced convection due to movement of the vehicle and slipstream channeled into the batteries. Alternatively, it may be pumped air or other pumped cooling fluid.

[0046] The coolant may either be circulated directly through these triangular gaps 630, or through pipes that pass through the triangular gaps 630.

[0047] By whatever means the coolant circulates through the triangular gaps 630, the coolant also has space to pass above and below the cells. This allows for the coolant to pass both vertically through the triangular gaps 630, and across the tops and bottoms of the cells 600 within the battery.

[0048] The busbars 510 and 560 may serve as cooling plates to the batteries.

[0049] The electrical insulating layer 500, 520, 550 and 570 may be used as channels for cooling fluid.

[0050] When a cell in isolation is subjected to end-to-end axial compression, it eventually fails by buckling outwards to form a barrel shape. Joining cylindrical cells 600 along the line of contact provides an increased axial compressive load bearing capability compared to the axial compressive load bearing capability of a single cell. I.e. for the seven cells shown cross-hatched, the center cell 620 is supported on six sides by other cells that prevent cell 620 from buckling outward. For cylindrical cells 600 bonded as in Figure 6, the overall compressive load bearing capability would be higher than the sum of the load bearing capability of all the individual cylindrical cells 600.

[0051] Batteries may be connected in parallel or series arrangements as is possible for all batteries.

[0052] Figure 7 illustrates a side on view of the hexagonal arrangement of a plurality of cylindrical cells 720 as described above referring to Figure 5.

[0053] Each cylindrical cell 720 has a positive terminal 721 and negative terminal 722, and an indent 723. In the view shown in Figure 7, the part of the cylindrical cell 720 above the indent 723 is part of the positive terminal 721, and the part of the cylindrical cell below the indent 723 is part of the negative terminal 722.

[0054] The positive terminal 721 interfaces with the upper layer 710, which comprises insulation 520 and bus bar 510, which in turn is covered by an insulating cap 700.

[0055] The negative terminal 722 interfaces with the lower layer 730, which comprises insulation 550 and bus bar 560, which in turn is covered by an insulating cap 740.

[0056] Each of these layers serves the same purposes as described above in reference to Figure 5.

[0057] Figure 8 illustrates a top down view of cylindrical cells 800 joined with a bonding material 810 along a line on either side of and parallel to the line of contact where the cylindrical cells touch when arranged in a hexagonal pattern in a same plane. Three rows of cells are shown, but there may be more or fewer.

[0058] This alternative arrangement of bonding material 810 provides a lower axial compressive load bearing capability compared to the axial compressive load bearing capability of the arrangement of Fig. 6, and also less than the sum of the individual cylindrical cells. The reason the arrangement of Figure 6 is preferred is because there is a leverage effect between the point of contact of two cells and the point of bonding. A sideways or shear force on the cells of Figure 8 causes two cells to roll against each other. This rolling can pull apart the bond if the bond is not at the point of contact. It may also be noted that the arrangement of Fig. 8 requires more bonding material. Nevertheless, the arrangement of Fig. 8 may have other advantages such as ease of manufacture. It can be manufactured by first placing cells side-by-side and then applying a line of bonding material (rather than applying the material and then placing the cells together).

[0059] Other arrangements may be preferred, for example in which each row of cells is bonded as shown in Figure 8 but rows are placed together side-by-side (or laid horizontally and mounted on top of each other) and bonded as shown in Figure 6.

[0060] The cells as arranged in Figure 6 or 8 may not necessarily all be in the same orientation. The simplest arrangement of cells is to have all cells within the battery in parallel, as this allows for a simple construction and bus bar. The cells may be arranged such that some cells within the battery are in opposite orientation to other cells. E.g., a row or block of cells within the battery may be in one orientation and connected in series with another row or block in an opposite orientation. Such an arrangement of cells requires separated bus bar sections and does not excessively complicate the construction and bus bar.

[0061] When containing cells 600 within a battery container, the container is preferably cuboidal in shape, but any shape that fit all the cells 600 would suffice. The outermost cells 600 of the battery are preferably rigidly fixed to the inside of the battery container.

This fixing can be done with a similar bonding material to bonding material 610 used to bond cells 600 together, or any other bonding material.

[0062] The battery container should thus be similar in size to the battery in order to facilitate a rigid fixing of the battery to the battery container. The size of the battery container should also take into account the coolant system (if any), and may allow for some extra room both above and below the battery.

[0063] There may be grooves, channels or other textures in the lid and/or floor of the battery container to direct coolant flow across the top of the battery, through the triangular gaps between the cells and through similar channels or other features across the bottom of the battery to be returned to a radiator for cooling and/or a pump for recirculating. Alternatively, there may be continuous pipes running up and down each row of gaps between cells, the pipes originating and separating from an inlet manifold and re-joining at an outlet manifold. Alternatively, the lid may serve as a manifold for pipes passing between the cells and the floor may serve as another manifold. The battery container may also have holes that allow for coolant to flow, either directly or through pipes, in and out of the battery and battery container.

[0064] The battery container also requires fixing to external structures, such as a monocoque or other vehicle body. This fixing may be a bonding material similar to that used for bonding cells together. The fixing may also be a more mechanical fixing, such as attaching the battery container via screws or bolts to any structure. Any mechanical fixing may also include brackets, or welding, or other fixing means.

[0065] Figure 9 illustrates a cross section of the hull of a boat, watercraft, or ship. This hull has an inner layer 900 and outer layer 910. The space between these layers may contain batteries as previously described.

[0066] The cells of the batteries may be located in a radial direction, i.e. with the axial dimension of the cells mounted normal to the hull, i.e. "vertically" with inner and outer busbars attached on the positive and negative terminals. However, the cells can be arranged "horizontally". In this arrangement, the cells lie parallel to the inner and outer layers 900 and 910 (the sandwich layer is placed radially on the cell) and each busbar extends in an annulus around the vehicle. This configuration works very well for circular or curved requirements such as aircraft hulls. Indeed, the individual cells are more resistive to radial compression than axial compression and, with adhesive between them to stop them rolling against each other, the construction is very strong.

[0067] Suitable locations for the batteries are 911, 912, 913 and 914. Batteries in these positions contribute to/increase the overall rigidity and structural integrity of the boat. Lower positions 912 and 913, close to the keel 930, are preferred for stability, but other locations 911 and 914 may be preferred for protection against impact forces in areas that may be vulnerable to collision. Batteries of equal weight are preferably positioned in pairs on port and starboard sides, at equal distance from the centerline of the boat.

[0068] Figure 10 illustrates a cross section of an aerofoil or wing 1000. It has a spar web 1020, a spar cap 1030, a number of left-to-right stringers 1050 and a number of fore-and-aft transverse ribs 1070. A space 1010 inside the aerofoil or wing may be used as space for batteries. The batteries may run substantially most of the length along an aircraft wing, from the fuselage (not shown) to almost the tip (not shown), In this way, the batteries can serve as a beam to contribute to the overall rigidity and structural integrity of the wing.

[0069] With such batteries, other internal reinforcing structures can be omitted. For example, there may be stringers forward and rearward of the batteries but none in the vicinity of the batteries. Equally, there need not be a web where the batteries extend. Alternatively, the batteries could be placed further forward in the position of web 1020 and web foot 1030 and these components may be omitted.

[0070] In this way structural components are replaced by batteries, which also serve the same structural purpose as the structure replaced.

[0071] Figure 11 illustrates an aircraft cabin cross section. The cabin has an outer skin 1100, and inner skin 1110. Three locations have been illustrated as places for batteries between the inner skin 1110 and outer skin 1100. These are shown by batteries 1130, 1160, and 1180.

[0072] To account for the possibility that these batteries 1130, 1160, and 1180 may be larger than the current space between inner skin 1100 and outer skin 1110, a bulge in the inner skin 1100 has also been illustrated by 1120, 1150, and 1170.

[0073] The space 1140 is typically used for luggage, and may have other various structures filling the space. Batteries may also be used to contribute to the overall rigidity and structural integrity of any structures in this space, as well as to the cabin.

[0074] If the cells are placed in the "horizontal" orientations, there may be no need for any bulges. The cells can fit in the space between the inner and outer skins of the fuselage.

[0075] As another example we may consider a monocoque fuselage of a helicopter or eVTOL craft. It may have a nose, a tail, a forward floor panel, a mid floor panel and a rear floor panel. It may have upper ribs and lower ribs. A reinforcing rib may also be present and integral to the rear floor panel. This is optional, as will be explained. All the aforesaid elements are integrally constructed as a monocoque structure.

[0076] There may be large holes left and right for doors, a large hole at the front for a windscreen and other holes near the tail for smaller windows or access panels.

[0077] Each of the floor panels may be constructed of inner and outer layers (skins) with filler material therebetween. The filler material may have voids throughout. The entire construction is strong and lightweight and has good crash resistance.

[0078] The reinforcing rib may be used as a location for batteries. Alternatively, where the batteries are located between the layers of the monocoque structure, the rib may be unnecessary.

[0079] The batteries are preferably located in the floor behind (rearward of) the occupants (pilot, co-pilot, passenger) and/or beneath the occupants.

[0080] Batteries as described with reference to Figs. 5-8.

[0081] Figure 12 illustrates a portion of a cylindrical cell (e.g. 530, 720) including the positive terminal. This portion of a cylindrical cell has an outer casing 1200 (also the negative terminal), a positive terminal contact 1210, a vent 1215, plastic inserts 1220 and 1250, a top disk 1240, scoring in the top disk 1245, a bottom disk 1260, a metallic foil 1270, a tab 1280, an indent 1290, and a thermal fuse 1230 between the top disc 1240 and the positive terminal 1210.

[0082] The outer casing 1200 serves as a negative terminal. The positive terminal contact 1210 connects to the positive terminal of the cell through the thermal fuse 1230, top disk 1240, and tab 1280. The vent 1215 in the positive terminal contact 1210 prevents the pressure between the positive terminal contact 1210 and the internals of the battery from rising much higher than the pressure external to the positive terminal contact 1210, thus preventing any explosions.

[0083] The scoring in the top disk 1240 encourages a certain failure mode of the battery in the case of the internals expanding due to heat or other causes. The plastic inserts 1220 serves to insulate the positive terminal contact 1210 from the negative terminal 1200, and plastic insert 1250 serves to insulate the top disk 1240 from the bottom disk 1260. The indent 1290 in the outer casing 1200 crimps the layers 1210-1260 together.

[0084] Referring to Fig. 13, a group of cells similar to those described with reference to Fig. 6 (or Fig 8) are shown in their "horizontal" orientation, that is to say, they lie parallel to a layer of a monocoque structure, for example an outer skin 1300. Between the skin and the cells are bonding material 1310 and 1320, that bond the cells to the skin. A similar arrangement is provided for an inner skin.

[0085] A busbar 1340 lies along each of the terminals of the cells. Only one such busbar is shown, for example contacting the negative terminals but it will be understood that another busbar or similar connections are provided for the positive terminals. The busbar may be curved to match the curve of the monocoque structure.

[0086] Fig. 13 illustrates how cells in this orientation can follow the contour or the skin 1400 of a monocoque structure and bonding material hold the outermost layer or row in place so that inner layers that are bonded to the outer layer are also help rigidity. In the same way, there is bonding material across an innermost layer of cells bonding to an inner skin of the monocoque structure.

[0087] Although the arrangement of Fig. 13 is shown in relation to an outer layer or skin, it can be applied to an inner layer only or to both inner and outer layers.

[0088] The above description and the accompanying drawings have been given by way of example only and modifications can be made within the scope of the claims.

Claims

Claims 1. A battery comprising cylindrical cells held together by a bonding material in a hexagonal pattern in a same plane, bonding a surface of a cell to an adjacent surface of an adjacent cell with triangular gaps between the cells.
2. The battery of claim 1, wherein the cylindrical cells are fixed to a layered structure and are oriented perpendicular to a layer of the structure.
3. The battery of claim 1 or 2, wherein the cylindrical cells are fixed to a layered structure and are oriented parallel to a layer of the structure.
4. The battery of any one of claims 1 to 3, wherein the non-conductive bonding material is applied along a line of contact of adjacent cylindrical cells.
5. The battery of any one of claims 1 to 4, wherein each cylindrical cell is connected to a bus bar.
6. The battery of claim 1to 5, wherein the positive terminals of each cylindrical cell is connected to the bus bar via a fuse.
7. The battery of any one of claims 1 to 6, wherein each cylindrical cell has its positive terminal electrically insulated from all neighboring cylindrical cell terminals other than via the bus bar.
8. The battery of any one of claims 1 to 7, wherein the cylindrical cells are held within a cuboidal container.
9. The battery of any one of claims 1 to 8, wherein the cylindrical cells are orientated in alternating polarization.
10. A vehicle comprising a. a body having first and second layers that form at least part of a monocoque structure; b. a battery in accordance with any one of the preceding claims, wherein the battery is located between the first and second layers and c. connecting means for mechanically fixing the battery to the first and second layers.
11. The vehicle of claim 10 wherein one of the first and second layers is an outer skin of the vehicle.
12. The vehicle of claim 11, wherein the battery has a positive terminal and a negative terminal and the negative terminal is electrically connected to the outer skin.
13. The vehicle of any one of claims 10 to 12, wherein the vehicle is an automobile, motorbike, scooter, e-mobility platform, watercraft, submarine, eVTOL helicopter or aircraft.
14. A method of manufacture of a battery, comprising: a. providing a plurality of cylindrical cells; and b. bonding surfaces of the cells to adjacent surfaces of adjacent cells in a hexagonal pattern in a same plane, with triangular gaps between the cells.
15. The method of manufacture of claim 14, wherein the cell surfaces are bonded with a single line of bonding material along a line of contact of adjacent cells.
16. A method of manufacturing a vehicle comprising manufacturing a battery in accordance with claim 14 or 15, manufacturing a vehicle comprising a body having first and second layers that form at least part of a monocoque structure; c. placing the battery between the first and second layers; and d. mechanically fixing the battery to the first and second layers via connecting means.
17. The method of manufacture of claim 16, wherein the connecting means is one of welding, gluing, bolting and riveting.