SE2251428A1 - Flexible cell spacer design - Google Patents

Abstract

A device for separating adjacent cells in a pouch battery cell system, and methods of making the same. The device comprises first and second sheets (101, 102); a resiliently deformable material (104) positioned between the first and second sheets (101, 102); and one or more voids (108) located between the first and second sheets (101, 102), in and/or around the resiliently deformable material (104).

Description

FIELD OF THE INVENTION This disclosure relates to a device for separating adjacent cells in a pouch battery cell system. This disclosure also relates to a pouch battery cell system comprising said device and a method of making the device.

BACKGROUND Pouch battery cells comprise an electrochemical cell housed within a pouch. The pouch may be formed from a flexible sheet material to provide a non-rigid enclosure for the electrochemical cell, as opposed to a rigid can or casing used for other types of battery cells. During use of the pouch battery cells, gases may be generated that cause the pouch to swell. This may cause pressure to build within the pouch during use, which may, in turn, lead to rupture of the pouch and the violent ejection of material.

Further, a plurality of pouch battery cells may be mounted together in a single pouch battery cell system. If multiple pouches swell, the build-up of pressure can be amplified. Also, the ejection of material from one of the pouch battery cells can cause damage to nearby cells.

The electrochemical cell within the pouch may experience thermal runaway, in which there is uncontrolled self-heating. Thermal runaway may be caused by damage to the pouch battery cell or, in particular, the electrochemical cell housed therein. Thermal runaway can cause or exacerbate issues of pressure build up. The increased temperatures in the battery cell system can also cause damage to adjacent electrochemical cells, triggering further thermal runaway events.

SUMMARY OF THE INVENTION According to a first aspect of this disclosure there is provided a device, or spacer, for separating adjacent cells in a pouch battery cell system, the device comprising: first and second sheets; a resiliently deformable material positioned between the first and second sheets; and one or more voids located between the first and second sheets, in and/or around the resiliently deformable material.

In one or more embodiments, the first sheet, the resiliently deformable material and the second sheet may be joined together in a laminar configuration.

In one or more embodiments, the resiliently deformable material may separate the first and second sheets from one another when no compression is applied to the device.

In one or more embodiments, the first and second sheets may extend substantially parallel to one another when no compression is applied to the device.

In one or more embodiments, each of the first and second sheets may comprise a substantially rigid material.

In one or more embodiments, each of the first and second sheets may be bendable, optionally elastically bendable.

In one or more embodiments, the resiliently deformable material may be elastically compressible.

In one or more embodiments, the resiliently deformable material may comprise: a plurality of elements separated from one another by at least one of the one or more voids; a mesh or web with at least one of the one or more voids located within the mesh or web; or a combination thereof.

In one or more embodiments, the resiliently deformable material has a dispensable state, in which the resiliently deformable material is dispensable onto one or both of the sheets during manufacture of the device, and a cured state in which the resiliently deformable material is affixed to the first and second sheets and is resiliently deformable.

In one or more embodiments, the cured resiliently deformable material may join the first and second sheets together.

In one or more embodiments, the device may further comprise an adhesive element affixing the resiliently deformable material to at least one of the first and second sheets.

In one or more embodiments, the resiliently deformable material may cover less than 50 percent of a surface of each of first and second sheets, preferably less than 40 percent, more preferably less than 30 percent.

In one or more embodiments, the ratio of resiliently deformable material to void per unit of volume between the first and second sheets may be substantially consistent across the entire volume between the first and second sheets.

In one or more embodiments, the ratio of resiliently deformable material to void per unit of volume between the first and second sheets may vary across the entire volume between the first and second sheets.

In one or more embodiments, the resiliently deformable material may comprise a material with a Young's modulus value from 0.01 GPa to 1 GPa.

In one or more embodiments, the resiliently deformable material comprises at least one of: silicone, a polymer, spring steel, glass fibres and natural fibres.

In one or more embodiments, the first and second sheets comprise at least one of: mica, a metal, a polymer, carbon fibres and glass fibres.

According to a second aspect of this disclosure there is provided a pouch battery cell system comprising: two pouch battery cells; and a device according to any embodiment of the first aspect of this disclosure.

According to a third aspect of this disclosure there is provided a method of making a device for separating adjacent cells in a pouch battery cell system, comprising: dispensing a resiliently deformable material, in a dispensable state, onto one or both of a first sheet and a second sheet; placing the first sheet onto the second sheet such that the dispensed resiliently deformable material is positioned between the first and second sheets; curing the resiliently deformable material, to a cured state, thereby affixing the first sheet to the second sheet via the resiliently deformable material to form the device, wherein the resiliently deformable material is dispensed in a configuration causing the device to comprise one or more voids located between the first and second sheets, in or around the resiliently deformable material.

In one or more embodiments, dispensing the resiliently deformable material may comprise dispensing a plurality of elements separated from one another.

In one or more embodiments, dispensing the resiliently deformable material may comprise dispensing a mesh or web comprising at least one of the one or more voids within the mesh or web.

In one or more embodiments, curing the resiliently deformable material may comprise raising the temperature of the resiliently deformable material and/or allowing the resiliently deformable material to cure for a predetermined period of time.

BRIEF DESCRIPTION OF THE DRAWINGS One or more embodiments will now be described by way of example only with reference to the accompanying drawings in which: Figures 1 and 2 show an example of a pouch battery cell; Figures 3 and 4 show an example embodiment of a device according to the present disclosure; Figure 5 shows an example embodiment of a pouch battery cell system according to the present disclosure, the system comprising a plurality of the device shown in Figures 3 and 4; Figures 6 to 8 each show another example embodiment of a device according to the present disclosure, each example showing a different arrangement resiliently deformable material elements separated from one another; Figure 9 shows a further example embodiment of a device according to the present disclosure, this example comprising a mesh of resiliently deformable material; Figure 10 shows an example embodiment of a method of making a device according to the present disclosure; and Figures 11 and 12 show an example embodiments of a method of making a pouch battery cell system according to the present disclosure.

Detailed Description Embodiments of the present disclosure will now be described more fully hereinafter, with reference to the figures. The same reference numbers are used throughout the figures. The invention may, however, be embodied in many different forms and should not be construed as limited to the embodiments set forth herein; rather, these embodiments are provided by way of example so that this disclosure will be thorough and complete, and will fully convey the scope of the invention to those persons skilled in the art.

Figures 1 and 2 show a pouch battery cell 2 (also referred to as the cell 2 from here on). The cell 2 comprises an electrochemical cell 6 and a pouch 4 configured to house the electrochemical cell 6. It will be appreciated that the electrochemical cell 6 is hidden from view in Figure 1 due to being housed in the pouch 4 but is located within the pouch 4, as shown in Figure 2.

The electrochemical cell 6 may comprise a secondary cell, although the electrochemical cell 6 may be a primary cell or other cell type. As will be familiar to those skilled in the art, the electrochemical cell 6 may comprise an assembly of electrodes and electrolyte for producing and storing electrical energy. In a pouch battery cell, the electrodes and electrolyte are typically formed in a series of layers. It will however be appreciated that the form of the electrochemical cell is not the focus in this document. The pouch 4 may be configured to provide an outermost layer to contain the electrodes and electrolyte therein.

The pouch 4 may be formed of two layers of a flexible sheet material, such as a film, (although further sub-layers may or may not be present) that are sealed together at their peripheral edge to form a peripheral flange 7. The sealing of the layers of the It will be appreciated that the pouch 4 may comprise a non-structural housing and may be a pouch 4 thereby seals the electrochemical cell 6 within the pouch 4. flexible, or non-rigid, housing due to the material forming the pouch being flexible. This means that the shape held by the pouch 4 is determined largely by the contents of the pouch 4 (the electrochemical cell 6) rather than particular properties of the pouch 4 or the material that forms the pouch 4.

The pouch battery cell 2 includes at least a first connector arrangement 104 configured to extend through the peripheral flange 7 and provide for electrical connection to the electrochemical cell 6 housed within the pouch 4. In the present example, the pouch battery cell 2 comprises only the first connector arrangement 14, although other examples may include more than one connector arrangement 14. Generally, the connector arrangement comprises a positive connector terminal and a negative connector terminal. In the present example, the positive and negative connector terminals are formed by respective tabs 15, 16 which extend between the two (or more) layers of the pouch 4. It will be appreciated that the pouch battery cell 2 may include other forms of connector arrangement, such as wires or other tab arrangements. The peripheral flange 7, in the region of the connector arrangement 14, may include one or more additional structures or layers to seal around the connector arrangement 14.

In general, and with reference to Figures 1 and 2, the pouch 4 comprises a first major surface 8 shown facing the viewer in figure 1 and a second major surface 9 arranged opposite the first major surface. The second major surface 9 is facing away from the viewer and is hidden in Figure 1 and is therefore shown with a dashed lead line. The first and second major surfaces 8, 9 may be formed by respective film layers of the pouch. The pouch 4 may include two or more peripheral edges or edge portions depending on its shape. The first major surface 8 and the second major surface 9 are sealed together at said two or more peripheral edges to form the peripheral flange 7. In the present example, the pouch 4 is substantially rectangular and therefore there are four peripheral edges 10, 11, 12 and 13.

The peripheral edges comprise the first edge 10, the second edge 11, the third edge 12 and the fourth edge 13. Thus, the first edge 10 and the third edge 12 are arranged opposite one another on opposite sides of the electrochemical cell within the pouch. The second edge 11 and the fourth edge 13 are arranged opposite one another on opposite sides of the electrochemical cell within the pouch. In this example, the second and fourth edges 11, 13 are longer edges than the first and third edges 10, 12.

When the pouch battery cell 2 is in use, gases may be generated by the electrochemical cell 6 that cause the pouch 4 to swell. In particular, the first and second major surfaces 8, 9 may expand outwardly, away from one another. Over time, pressure may build within the pouch 4 during use, which may, in turn, lead to rupture of the pouch 4 and the violent ejection of material.

The build-up of pressure can be exacerbated if the two or more pouch battery cells 2 are mounted or stacked together in a single pouch battery cell system such that the major surfaces 8, 9 press against one another as the pouch 4 expands.

It is therefore preferable to separate adjacent pouch battery cells from one another to mitigate against the pressure build up caused by cell swelling and provide thermal insulation between adjacent pouch battery cells.

Figures 3 and 4 shows a device 100, or spacer, for separating adjacent cells in a pouch battery cell system. The device comprises first and second sheets 101, 102 and a resiliently deformable material 104 positioned between the first and second sheets 101, 102.

In this embodiment, the resiliently deformable material 104 comprises a plurality of elements 106 separated from one another.

The device 100 further comprises a void 108 located between the first and second sheets 101, 102 and around the various elements 106 of resiliently deformable material 104.

The arrangement of the resiliently deformable material 104 and the void 108 is more clearly visible in "top' view of Figure 4. However, it will be appreciated that the first sheet 101 has been removed from the drawing to provide the improved view.

The first sheet 101, the resiliently deformable material 104 and the second sheet 102 are joined together in a laminar configuration such that, when no compression is applied to the device 100, the resiliently deformable material 104 separates the first and second sheets 101, 102 from one another and the first and second sheets 101, 102 extend substantially parallel to one another.

The first and second sheets 101, 102 may be considered as "structural' in nature for the reason that each sheet contributes to the structure of the overall device 100. Each sheet 101, 102 may comprise a substantially rigid material and each sheet 101, 102 may therefore be sufficiently rigid and stiff to substantially hold its shape when no forces are applied normal to the plane of the sheet.

However, the sheets 101, 102 may be sufficiently thin such that the sheets 101, 102 are not entirely rigid or stiff, despite being formed from a substantially rigid material. Rather, each sheet may have a degree of flexibility to allow the sheets to flex (or bend) when a sufficient force is applied. In other words, the first and second sheets may be bendable. For example, the sheets 101, 102 may be formed from a sheet metal.

The bendability of the first and second sheets 101, 102 may be adapted to a particular application by any suitable means. For example, the first and second sheets 101, 102 may be perforated wherein a greater concentration of perforations per unit area of sheet results in greater bendability and a lower concentration of perforations (or none at all) results in reduced bendability. Furthermore, the concentration of perforations may be varied across the first and second sheets 101, 102 to provide particular regions with greater bendability or stiffness as may be required.

In other embodiments, the first and second sheets 101, 102 may be entirely rigid, or non-bendable.

The bendability of the first and second sheets 101, 102 (or the lack thereof) may also be adapted through material selection. The first and second sheets 101, 102 may comprise at least one of mica, steel or another metal, a polymer, carbon fibres and glass fibres.

The material selection may also affect the elasticity of the first and second sheets 101, 102. In some embodiments, a material may be selected to provide the first and second sheets 101, 102 with sufficient elasticity to be elastically bendable through the entire range of flexion or bending that would be expected of the first and second sheets 101, 102 in normal use. In other words, the first and second sheets 101, 102 would return to a natural, flat, state when no forces are applied. In other embodiments of the invention, the first and second sheets 101, 102 may not require elasticity as the resiliently deformable material between the sheets may provide the device 100 with sufficient elasticity to return to its normal shape.

In some embodiments, the first and second sheets 101, 102 may be integral as a single sheet of material that is folded to form the first and second sheets 101, 102.

The resiliently deformable material 104 comprises a softer, more readily deformable, material than the first and second sheets 101, 102. The resiliently deformable material is at least partially elastic in nature whereby the elasticity of the resiliently deformable material 104 means that it will at least partially return to its natural shape when no forces are being applied to is. Preferably, the resiliently deformable material is elastically deformable. More preferably, the resiliently deformable material is elastically compressible. The resiliently deformable material may also have a Young's modulus value from 0.01 GPa to 1 Gpa.

The resiliently deformable material 104 may comprise at least one of silicone, a polymer, spring steel, glass fibres and natural fibres. In some embodiments, the resiliently deformable material extends substantially continuously from the first sheet to the second sheet. However, in other embodiments, the resiliently deformable material could be "non-continuous', for example the resiliently deformable material may comprise a foam or felt structure.

Figure 5 shows a pouch battery cell system 150 comprising a plurality of pouch battery cells 2 and a plurality of devices 100 arranged such that each pair of adjacent cells 2 is separated by a respective device 100. In particular, each device 100 is positioned next to a major surface 8, 9 of a respective cell 2.

As mentioned above, in use, the pouch battery cells 2 may swell, particularly causing the major surfaces 8, 9 to expand outwardly.

If the devices 100 are not present, the pouches 4 will expand in an uncontrolled manner and the pouches 4 will be prone to eventual rupture. The failure of one pouch 4 may also lead to the failure of other pouches which are unprotected from temperature rises and material ejection.

The devices 100 firstly act to space the pouch battery cells 2 apart so that, when the cells 2 expand, they expand against the adjacent devices 100 rather than the adjacent cells 2. This allows for a degree of cell/pouch expansion to occur in a controlled manner, reducing the likelihood of irregular swelling that may lead to rupture.

The presence of the void 108 surrounding each element 106 of the elastically deformable material means that the resiliently deformable material 104 has plenty of space to expand into across the plane of the device 100, thereby allowing greater compression of the resiliently deformable material 104 in the direction normal to the plane of the device 100. Accordingly, a much greater movement of the first and second sheets 101, 102 towards one another can be achieved than would be the case if a continuous resiliently deformable material was used, because a continuous resiliently deformable material would be able expand only towards the edges of the device in order to compensate for compression in the direction normal to the plane of the device 100.

The void 108 also improves the thermal insulation provided by the device 100.

In addition to the device 100 spacing adjacent cells 2 apart and being compressible to allow for expansion of the cells 2, the devices 100 also counteract pressures building up within adjacent pouches 4 so that swelling caused by the pressure build-up is limited. Moreover, the devices 100 assist with distribution of pressure across the pouches 4 so that the limitation of swelling occurs in a controlled manner reducing the risk of a pouch 4 rupturing.

When the cells 2 swell, the expansion is typically greatest towards the centre of the major surfaces 8, 9. This means that the pressures exerted on the pouches 4 are also typically greatest towards the centre of the major surfaces 8, 9. However, to reduce the possibility of the pouch 4 rupturing, it is preferable to prevent pressure from building up in a small area.

By virtue of the rigidity of the material forming the sheets 101, 102 (relative to the pouch material and the resiliently deformable material), movement of the sheets 101, 102 acts to spread the forces resulting from pressure build-up across the major surfaces 8, 9.

This offers an improvement over what might be achieved by if, for example, the resiliently deformable material was used in isolation to separate adjacent pouch cells. Without the sheets 101, 102 positioned on either side, the resiliently deformable material would only distribute forces over the small area that the material is present. This may allow the forces resulting from pressure build-up to converge at a particular location, thereby increasing the risk of the pouch 4 rupturing.

In the device 100 shown in Figures 3 and 4, the resiliently deformable material elements 106 are evenly distributed across the device 100 so that the compressibility of the device, and the ability of the device to distribute forces, is substantially uniform across the first and second sheets 101, 102.

However, in other embodiments of the device, it is possible to tailor these characteristics of the device as may be required by a particular application.

For example, Figure 6 shows a device 200 which comprises the same sheets 101, 102 (although the first sheet is not shown) and the same resiliently deformable material 104 except, in this embodiment, the elements 206 of resiliently deformable material 104 are arranged differently. In particular, the concentration of elements 206 is greater at the corners of the device 200 and reduced in the centre of the device 200.

The void 208 therefore dominates the middle portion of the device 200 to a much greater degree than in the device 100 shown in Figures 3 and 4.

This arrangement of the resiliently deformable material elements 206 results in the device 200 having greater compressibility in the middle portion of device. However, the distribution of forces away from the centre of the device will be less effective as a result of the reduced resiliently deformable material.

Such an arrangement may be preferable if the degree of cell expansion likely to occur is well known and the primary intention for the device is to provide space for the adjacent cells to expand into while still resiliently acting to space the two adjacent cells apart from one another, at least at their edges or corners.

In contrast, Figure 7 shows a device 300 in which the resiliently deformable material elements 306 are more concentrated in the centre of device and more spaced apart from one another towards the edges of the device.

This arrangement of the resiliently deformable material elements 306 results in the device 300 providing more resistance to compression in the middle portion of device and greater ability to manage force concentration in the centre of the adjacent pouches.

Such an arrangement may be preferable if the degree of cell expansion likely to occur is less well known and the primary intention for the device is to distribute forces that arise as a result of cell expansion. Further, the reduction of resiliently deformable material at the edges, where problems associated with cell expansion are not as significant, may allow for reduction of material costs.

Figures 4, 6 and 7 each disclose devices with dot-like elements 106, 206, 306 of resiliently deformable material. However, any suitable configuration of the resiliently deformable material elements may be used. For example, Figure shows a device 400 in which the resiliently deformable material 104 comprises a plurality of line-shaped elements 406 that are more spread out in the middle of the device 400 and more concentrated towards the edges (similarly to the embodiment shown in Figure 6).

It is also possible for the resiliently deformable material to comprise a mesh or web of interconnected portions or strands. For example, Figure 9 shows a device 500 comprising a mesh 508 or resiliently deformable material 104. Again, similarly to the 11 embodiments of the device shown in Figures 6 and 8, the resiliently deformable material is more densely arranged at the edges of the device 500 while having a lower concentration of material in the middle portion.

Although a "web' is not shown, it will be appreciated that a similar configuration of the resiliently deformable material except with a shape more analogous to a spider's web would also be suitable. A web may be particularly useful if the intention is to have a higher ratio of resiliently deformable material to void towards the centre of the device.

In such embodiments of the device that include a mesh or web of resiliently deformable material there is a plurality of voids located within the mesh or web rather than a single void located around the elements of resiliently deformable material.

It is also possible to use configurations of the resiliently deformable material that combine separate elements with one or more meshes or webs. This flexibility of the configurations and arrangements of the resiliently deformable material within a particular device allow a user to tailor the properties of the device very specifically to the requirements of a particular application, such as the expected cell expansion, the strength of the pouch material (or lack thereof) and possible cost restrictions.

Although the precise configuration of resiliently deformable material is to be tailored to the intended use of the device, it is preferred that the resiliently deformable material covers less than 50 percent of a surface of each of first and second sheets to allow the resiliently deformable material sufficient space to deform as intended. In some embodiments, it may be preferable for the resiliently deformable material to cover less than 40 percent of a surface of each of first and second sheets, or even less than 30 percent.

The devices 100, 200, 300, 400, 500, shown in Figures 3 to 9, may be made by any suitable method one method may include attaching the resiliently deformable material to the first and second sheets using a separate adhesive element, such as glue or adhesive tape.

Figure 10 shows another suitable method of making a device for separating adjacent cells in a pouch battery cell system. The method 600 is depicted with reference to the device 100, shown in Figures 3 to 5. However, the method is equally suitable for making the devices 200, 300, 400, 500 shown in Figures 6 to 9. 12 The method com prises: 602) dispensing a resiliently deformable material 104, in a dispensable state, onto a first sheet 101; 604) placing the first sheet 101 onto the second sheet 102 such that the dispensed resiliently deformable material 104 is positioned between the first and second sheets; and 606) curing the resiliently deformable material 104, to a cured state, thereby affixing the first sheet 101 to the second sheet 102 via the resiliently deformable material 104 to form the device 100.

In step 604, the resiliently deformable material 104 is dispensed in a configuration causing the device 100 to ultimately comprise one or more voids 108 located between the first and second sheets 101, 102, in or around the resiliently deformable material 104.

More particularly, in this example, dispensing the resiliently deformable material 104 comprises dispensing a plurality of elements 106 separated from one another. Therefore, ultimately, the device 100 comprises a single void 108 located between the first and second sheets 101, 102 and around the resiliently deformable material elements 106.

However, it will be appreciated that if the device 500 (shown in Figure 9) was being made by the same method, dispensing the resiliently deformable material 104 would comprise dispensing a mesh 506 comprising a plurality of voids 508 within the mesh 506.

Dispensing the resiliently deformable material 104 may involve a jet dispensing method, for increased manufacturing speed.

Other methods of making a device for separating adjacent cells in a pouch battery cell system may comprise forming a mesh or web of resiliently deformable material by way of extrusion or injection molding and then affixing the mesh or web between the first and second sheets. Referring back to Figure 10, particularly step 606, curing the resiliently deformable material 106 comprises allowing the resiliently deformable material to cure for a predetermined period of time. 13 In other embodiments, curing the resiliently deformable material 106 may alternatively or additionally comprise raising the temperature of the resiliently deformable material 106 to induce and/or accelerate the curing process.

A device for separating adjacent cells in a pouch battery cell system, such as any one of the devices 100, 200, 300, 400, 500 discussed above, may be incorporated into a pouch battery cell system by any suitable method and such methods will be readily understood by a person skilled in the art.

For example, the pouch battery cell system 150, shown in Figure 5, may be constructed by adhering, or otherwise affixing, the devices 100 to the respective cells 2.

Another possible method of making a pouch battery cell system incorporating a device for separating adjacent cells in a pouch battery cell system is shown in Figures 11 and 12.

Figure 11 first shows a tray 700. The tray 700 may comprise a unit part of a larger enclosure for a plurality of pouch battery cells.

The tray 700 comprises a surface 702 formed at least partially from a device, such as the device 100 shown in Figures 3 to 5. The tray 700 further comprises one or more raised sides 703 extending from outer edges of the surface 702.

A pouch battery cell, such as the pouch battery cell 2 shown in Figures 1 and 2, and a It will be appreciated that when the resilient strip 701 has pressure applied to it, it will provide resilient strip 701 are configured to be received within the tray 700. reinforcement of the peripheral flange 7 of the cell 2 by pressing it against the surface 702, device 100 and/or raised sides 703 of the tray 700.

The tray 700 may be considered a first tray which is configured to stack together with a second tray 705 to form, in part, the enclosure for a plurality of pouch battery cells 2. Thus, the trays 700, 705 have one pouch battery cell (or more in other embodiments) therebetween.

Figure 11 shows the first tray 700 and second tray 705 spaced apart and Figure 12 shows them stacked together. 14 The first tray 700 and the second tray 705 and the resilient strip 701 are configured such that when stacked together, the second tray 705 is configured to apply pressure to the resilient strip 701 to cause it to apply pressure to the peripheral flange 7. Thus, a base of the second tray 705 that is received within the first tray 700 is configured to contact the resilient strip 701.

In an alternative example, the resilient strip 701 may lie beneath the peripheral flange 701, such that when the trays 700, 705 are stacked together, the second tray 705 is configured to apply pressure to the peripheral flange 7 to press it against the resilient strip 701.

Any desired number of trays 700, 705, each comprising a device 100, and a corresponding number of pouch battery cells 2 may be stacked together so as to form a pouch battery cell system.

Although specific terms may be employed herein, they are used in a generic and descriptive sense only and not for purposes of limitation. Therefore, persons skilled in the art would recognize numerous variations to the described embodiments that would still fall within the scope of the appended claims. As used herein, the terms "comprise/comprises" or "include/includes" do not exclude the presence of other elements or steps. Furthermore, although individual features may be included in different claims (or embodiments), these may possibly advantageously be combined, and the inclusion of different claims (or embodiments) does not imply that a certain combination of features is not feasible and/or advantageous. In addition, singular references do not exclude a plurality. Finally, reference numerals in the claims are provided merely as a clarifying example and should not be construed as limiting the scope of the claims in any way.

Claims (22)

1. A device for separating adjacent cells in a pouch battery cell system, the device comprising: first and second sheets; a resiliently deformable material positioned between the first and second sheets; and one or more voids located between the first and second sheets, in and/or around the resiliently deformable material.

2. The device of claim 1, wherein the first sheet, the resiliently deformable material and the second sheet are joined together in a laminar configuration.

3. The device of claim 1 or claim 2, wherein the resiliently deformable material separates the first and second sheets from one another when no compression is applied to the device.

4. The device of any preceding claim, wherein the first and second sheets extend substantially parallel to one another when no compression is applied to the device.

5. The device of any preceding claim, wherein each of the first and second sheets comprises a substantially rigid material.

6. The device of any preceding claim, wherein each of the first and second sheets are bendable, optionally elastically bendable.

7. The device of any preceding claim, wherein the resiliently deformable material is elastically compressible.

8. The device of any preceding claim, wherein the resiliently deformable material comprises: a plurality of elements separated from one another by at least one of the one or more voids; a mesh or web with at least one of the one or more voids located within the mesh or web; or a combination thereof.

9. The device of any preceding claim, wherein the resiliently deformable material has a dispensable state, in which the resiliently deformable material is dispensable onto one or both of the sheets during manufacture of the device, and a cured state in which the resiliently deformable material is affixed to the first and second sheets and is resiliently deformable.

10. The device of claim 9, wherein the cured resiliently deformable material joins the first and second sheets together.

11. The device of any of claims 1 to 9, further comprising an adhesive element affixing the resiliently deformable material to at least one of the first and second sheets.

12. The device of any preceding claim, wherein the resiliently deformable material covers less than 50 percent of a surface of each of first and second sheets, preferably less than 40 percent, more preferably less than 30 percent.

13. The device of any preceding claim, wherein the ratio of resiliently deformable material to void per unit of volume between the first and second sheets is substantially consistent across the entire volume between the first and second sheets.

14. The device of any one of claims 1 to 12, wherein the ratio of resiliently deformable material to void per unit of volume between the first and second sheets varies across the entire volume between the first and second sheets.

15. The device of any preceding claim, wherein the resiliently deformable material comprises a material with a Young's modulus value from 0.01 GPa to 1 GPa.

16. The device of any preceding claim, wherein the resiliently deformable material comprises at least one of: silicone, a polymer, spring steel, glass fibres and natural fibres.

17. The device of any preceding claim, wherein the first and second sheets comprise at least one of: mica, a metal, a polymer, carbon fibres and glass fibres.

18. A pouch battery cell system comprising: two pouch battery cells; and the device of any preceding claim positioned between the two battery cells.

19. A method of making a device for separating adjacent cells in a pouch battery cell system, comprising: dispensing a resiliently deformable material, in a dispensable state, onto one or both of a first sheet and a second sheet; placing the first sheet onto the second sheet such that the dispensed resiliently deformable material is positioned between the first and second sheets; curing the resiliently deformable material, to a cured state, thereby affixing the first sheet to the second sheet via the resiliently deformable material to form the device, wherein the resiliently deformable material is dispensed in a configuration causing the device to comprise one or more voids located between the first and second sheets, in or around the resiliently deformable material.

20. The method of claim 19, wherein dispensing the resiliently deformable material comprises dispensing a plurality of elements separated from one another.

21. The method of claim 19 or claim 20, wherein dispensing the resiliently deformable material comprises dispensing a mesh or web comprising at least one of the one or more voids within the mesh or web.

22. The method of any of claims 18 to 20, wherein curing the resiliently deformable material comprises raising the temperature of the resiliently deformable material and/or allowing the resiliently deformable material to cure for a predetermined period of time.