GB2578486A

GB2578486A - Flexible battery

Info

Publication number: GB2578486A
Application number: GB1818167.7A
Authority: GB
Inventors: Kugler Thomas; O'Sullivan Melanie; Blincow Jack
Original assignee: Sumitomo Chemical Co Ltd
Current assignee: Sumitomo Chemical Co Ltd
Priority date: 2018-09-28
Filing date: 2018-11-07
Publication date: 2020-05-13
Also published as: GB2577577A; GB201818167D0; GB201904393D0

Abstract

A battery device comprises a battery cell 100 and an adhesive composition 111 disposed between anode and cathode current collectors 107, 109, the adhesive composition comprising an adhesive adhering the anode current collector to the cathode current collector, and an insulating spacer, e.g. a porous matrix such as a mesh, or a plurality of insulating particles, spacing the anode current collector from the cathode current collector. The anode 101 is joined to the anode current collector, the cathode 105 is joined to the cathode current collector, and a separator 103 is provided between the two electrodes. When the spacer is a mesh, it may be made from polymer, with the adhesive disposed in its pores. When the spacer is the plurality of particles, these may be made of ceramic, insulating polymer, or particles including a getter material. The insulating spacer helps to prevent short circuits from contact between the anode and cathode current collectors. Direct bonding of the battery's current collectors provides an encapsulated battery formed from its constituent electrodes, without the need for an encapsulating layer and without the risk of electrical shorting between the cathode and anode current collectors. The battery device is preferably flexible.

Description

Intellectual Property Office Application No. GII1818167.7 RTM Date:24 April 2019 The following terms are registered trade marks and should be read as such wherever they occur in this document: Cricut, Super P, Kapton and TECBON D. Intellectual Property Office is an operating name of the Patent Office www.gov.uk/ipo

FLEXIBLE BATTERY

BACKGROUND

Embodiments of the present disclosure relate to a battery device comprising a battery cell and a method of producing a battery device.

A battery device can be provided with a high charge capacity by increasing the number of or thickness of active material layers in the battery device. However, increasing the number or thickness of active material layers also increases the thickness of the resulting battery device. A thicker battery device generally has a lower flexibility.

A battery device has a cathode, a separator and an anode between an anode current io collector and a cathode current collector and additionally a means for sealing the cathode, anode and separator from their environment such as sealing layers or a sealing pouch which encapsulates the entire battery device, including the edges of the battery device, thereby forming a bather against ingress of water vapour, air and other fluids that may negatively affect the performance of the battery device.

A thinner, high capacity, battery device having a high degree of flexibility is desirable, particularly for wearable technology applications.

To reduce the thickness of a battery device, the thickness of active material layers can be reduced. However, reduction in the thickness of these layers may lead to lower capacity.

SUMMARY

A summary of aspects of certain embodiments disclosed herein is set forth below. It should be understood that these aspects are presented merely to provide the reader with a brief summary of these certain embodiments and that these aspects are not intended to limit the scope of this disclosure. Indeed, this disclosure may encompass a variety of aspects and/or a combination of aspects that may not be set forth.

A conventional battery requires a means of ensuring that electrical shorts between the anode and cathode components do not occur.

The present inventors have found that use of an adhesive composition comprising an insulating spacer and an adhesive to adhere the anode current collector to the cathode current collector, whilst maintaining a gap between the current collectors may provide protection against ingress of moisture and/or oxygen, whilst preventing electrical shorts.

As such, the present inventors have provided a battery device which is sealed from the external environment such that a separate sealing structure might not be required.

According to some embodiments of the present disclosure there is provided a battery device having a battery cell comprising an anode, a cathode and a separator between the anode and cathode. The battery cell is disposed in a battery area between a contact surface io of an anode current collector and a contact surface of a cathode current collector An adhesive composition is disposed in an adhesion area between the contact surface of the anode current collector and the contact surface of the cathode current collector The adhesive composition contains an adhesive adhering the anode current collector to the cathode current collector and an insulating spacer spacing the anode current collector from the cathode current collector.

In some embodiments, the insulating spacer is a porous matrix. In some embodiments, the porous matrix is a mesh. The mesh may be woven or non-woven. The mesh may have regular or irregular pores of any shape. In some embodiments, the porous matrix is a polymer. In some embodiments, the adhesive is disposed in the pores of the porous matrix.

In some embodiments, the insulating spacer is a plurality of insulating particles. In some embodiments, the insulating particles are ceramic particles In some embodiments, the insulating particles are dispersed in the adhesive.

In some embodiments, the adhesive is a thermosetting adhesive. In some embodiments, the adhesive is a thermoplastic.

The anode current collector and cathode current collector each contains or consists of a layer of conductive material. In some embodiments, the adhesion area surrounds the battery cell. hi some embodiments, the battery device is a flexible battery device.

According to some embodiments of the present disclosure there is provided a method of producing a battery device, comprising: providing an anode on a contact surface of a first current collector; providing a cathode on a contact surface of a second current collector; depositing an insulating spacer and an adhesive in an adhesion area on the contact surface of at least one of the first current collector and the second current collector; providing a separator between the anode and cathode; and adhering together the contact surfaces of the first and second current collectors.

The contact surfaces of the first and second current collectors of the battery device formed by the method described herein are spaced apart by the insulating spacer.

ht some embodiments, the insulating spacer is deposited before the adhesive. In some embodiments, the insulating spacer is deposited after the adhesive. In some embodiments, the insulating spacer and the adhesive are co-deposited.

In some embodiments, the adhesive and insulating spacer are provided on the contact surface of the first current collector only. In these embodiments, the anode may be formed on the first current collector contact surface before or after the insulating spacer is deposited, and before or after the adhesive is deposited.

In some embodiments, the adhesive and insulating spacer are provided on the contact surface of the second current collector only. In these embodiments, the cathode may be formed on the second current collector contact surface before or after the insulating spacer is deposited, and before or after the adhesive is deposited.

In some embodiments, the adhesive and insulating spacer are provided on the contact surfaces of both of the first and second current collectors. In these embodiments, the anode and cathode are each independently formed on the respective first and second current collector contact surfaces before or after the insulating spacer and / or adhesive is deposited on the respective current collector contact surfaces.

In some embodiments, there is a gap between the adhesion area and the battery cell area.

In some embodiments, the porous matrix defines a well for containment of active materials of the battery cell According to a third aspect of some embodiments of the present disclosure there is provided battery device manufactured by the method described herein.

BRIEF DESCRIPTION OF DRAWINGS

The present disclosure is described in conjunction with the appended figures. It is emphasized that., in accordance with the standard practice in the industry, various features are not drawn to scale. In fact, the dimensions of the various features may be arbitrarily increased or reduced for clarity of discussion.

ro In the appended figures, similar components and/or features may have the same reference label. Further, various components of the same type may be distinguished by following the reference label by a dash and a second label that distinguishes among the similar components. If only the first reference label is used in the specification, the description is applicable to any one of the similar components having the same first reference label irrespective of the second reference label.

Figure 1 illustrates a battery device, according to some embodiments of the present disclosure; Figure 2 illustrates a method of forming a polymer device, according to some embodiments of the present disclosure; Figure 3 is a graph of cyclic discharged capacity density vs. cycle number for a battery device, according to some embodiments; and Figure 4 is a graph of cyclic midpoint voltage vs. cycles for a battery device, according to some embodiments.

DETAILED DESCRIPTION

Some embodiments of the present disclosure provide a thermoplastic composite material for thermal sealing of flexible battery electrodes of a flexible battery. The composite is formed by impregnation of a thermoplastic bonding agent into the pores of a mesh material. The mesh material acts as a spacer to prevent shorts from electrode-electrode contact, and the thermoplastic bonding agent bonds the electrodes together when heated above the melting point of the bonding agent. The thermoplastic composite material bonds the flexible electrodes together to provide a highly conformable battery. Direct bonding of the battery's current provides an encapsulated battery formed from its constituent electrodes, without the need for an encapsulating layer and without the risk of electrical shorting between the cathode and anode current collectors. By removing the need for extra layers to encapsulate the electrodes and other material of the cell, the cell, in accordance with the present disclosure, is flexible/conformable and can be used in a wearable device, a wearable medical system and/or the like.

Figure 1, which is not drawn to any scale, schematically illustrates a battery device according to some embodiments. The battery device comprises at least one anode current collector 107, one cathode current collector 109, a battery cell 100 and an adhesive composition 111. The battery cell 100 comprises an anode 101, a cathode 105, and a separator 103 between the anode and the cathode.

According to some embodiments of the present disclosure there is provided a battery device comprising a battery cell comprising an anode, a cathode and a separator between the anode and cathode; wherein the battery cell is disposed in a battery area between a contact surface of an anode current collector and a contact surface of a cathode current collector; an adhesive composition is disposed in an adhesion area between the contact surface of the anode current collector and the contact surface of the cathode current collector; and the adhesive composition comprises an adhesive adhering the anode current collector to cathode current collector and an insulating spacer spacing the anode current collector from the cathode current collector.

Li some embodiments, the battery device has a thickness of no more than 1 mm, optionally in the range of 0.5-1 mm Adhesive Composition The adhesive composition comprises or consists of the insulating spacer and the adhesive.

In some embodiments, the insulating spacer is a porous matrix. In some embodiments, the 30 porous matrix is a mesh. In some embodiments, the porous matrix is a polymer. In some embodiments, the adhesive is disposed in the pores of the porous matrix. In some embodiments, the porous matrix has a thickness of between 30 and 300 p in, preferably 50 and 200 pm.

In some embodiments, the insulating spacer is a plurality of insulating particles. In some embodiments, the insulating particles are selected from: ceramic particles; insulating polymer particles; and getter particles.

Getter particles as described herein may comprise or consist of a material have oxygen and/or moisture-absorbing properties including, without limitation, oxides or hydroxides of alkali or alkali earth metals, e.g. oxides or hydroxides of calcium, barium or strontium; /0 aluminium oxide; zeolites; silica; ether-containing compounds, e.g. crown ethers, epoxy resins and polyethers; ascorbic acid; polyhydric alcohols; and alkylene glycols.

A porous matrix as described herein may support a material having oxygen and/or moisture-absorbing properties, for example materials as described above.

In some embodiments, the insulating particles are dispersed in the adhesive. In some /5 embodiments, the insulating particles have an average diameter of between 30 and 300 pm, preferably 50 and 150 pm.

In some embodiments, a perimeter of at least part of the battery area contacts at least part 90 of an inner perimeter of the adhesive area. In some embodiments, the whole of the inner perimeter of the adhesive area is in contact with the perimeter of the battery cell in the battery area.

In some embodiments, an outer perimeter of the adhesive composition does not extend beyond a perimeter of the battery device defined by the perimeter of an overlap area of the anode current collector and cathode current collector.

In some embodiments, an outer perimeter of the adhesive composition extends beyond, e.g. overhangs, a perimeter of the battery device defined by the perimeter of an overlap area of the anode current collector and cathode current collector.

Electrical shorting between edges of the anode and cathode current collector may be avoided or reduced if the adhesive composition extends to, and optionally beyond, a perimeter of the anode current collector and/or cathode current collector. The adhesive composition may extend beyond the perimeter of the anode current collector and/or cathode current collector by up to 20 mm, optionally up to 5 mm.

In some embodiments, the adhesive area defines a border around at least part of the perimeter of the battery cell. The border may have a width in the range of about 0.1-40 mm, optionally 3-20 mm or 3-10 mm.

In some embodiments, there may be a gap between the battery cell and the adhesive area. 10 In these embodiments, the battery cell separator may extend into the gap and contact the inner perimeter of the adhesive area to prevent an electrical short between the anode current collector and cathode current collector in the gap area.

In some embodiments, the adhesion area is disposed over 5% -20%, optionally 5% -10% of the surface area of at least one of the anode current collector and cathode current 15 collector.

In some embodiments, the adhesive composition forms a single layer. In some embodiments, the adhesive composition forms a layer extending between the contact surface of the anode current collector and the contact surface of the cathode current collector, and adheres these two layers together. In some embodiments, the adhesive composition layer is a continuous layer. In some embodiments, the adhesive composition layer is a plurality of spatially distinct regions.

In some embodiments, the adhesive composition layer seals the battery cell from the exterior of the battery device. In some embodiments, the seal is a thermal seal. In some embodiments, the adhesive composition layer is impermeable to gas and/or liquid.

In some embodiments, the adhesive composition layer provides an insulating spacer between the anode current collector and the cathode current collector, ensuring that the anode current collector and cathode current collector do not come into direct contact.

In some embodiments, the adhesive composition layer is between 10 and 500 p m thick.

Preferably, the adhesive composition layer is between 50 and 200 pm thick.

In some embodiments, the adhesive composition maintains a minimum separation distance between the anode current collector and the cathode current collector of between 10 pm and 100 pm, or preferably between 50 pm and 200 pm. The minimum separation distance may be selected according to the thickness of the battery cell.

Current collectors In some embodiments, the anode current collector and cathode current collector each independently comprise or consist of a layer of conductive material, for example a metal, e.g. copper or aluminium; a metal alloy, e.g. steel; a conductive metal oxide, e.g. indium io tin oxide; a conducting polymer, e.g. poly(ethylene dioxythiophene) or polyaniline; or a conductive carbon allotrope, e.g. amorphous carbon, graphene, carbon nanotubes, carbon fibre or graphite powder.

Each current collector may independently be single conductive layer which may or may not he laminated with one or more further layers. In some embodiments, the current collector may be laminated to a glass or plastic layer.

In some embodiments, the current collector may he a conductive layer which is part of a laminate further comprising at least one metal layer. In some embodiments, the laminate comprises the current collector layer, at least one polymer layer and at least one metal layer. One or more polymer layers may be provided between the current collector layer and the one or more metal layers.

In some embodiments, each current collector may be supported on a suitable substrate, for example a glass or plastic substrate. In some embodiments, the substrates may be flexible, particularly for applications in which flexibility of the battery is desirable, and / or to enable use of a roll-to-roll process in battery formation. In some embodiments, an exemplary flexible current collector is a metal foil, for example aluminium foil.

In some embodiments, the battery device is a flexible battery device.

Battery Cell The battery cell comprises an anode 101, a cathode 105, and a separator 103 between the anode 101 and the cathode 105. In some embodiments, the battery cell is a polymer battery cell in which the anode comprises an n-type polymer and the cathode comprises a p-type polymer. The anode and cathode may comprise any suitable materials known in the art The separator may be selected from separators known to the skilled person. The separator may contain an electrolyte. The electrolyte may be a liquid or a gel comprising an electrolyte solution or a liquid electrolyte. In some embodiments, the separator may be a solid polymer electrolyte. In some embodiments, the separator may comprise a mesh, for example a polymeric mesh, comprising electrolyte in the pores of the mesh.

In some embodiments, the electrolyte may be a dissolved salt or an ionic liquid. In some embodiments, the electrolyte may be a solution of a salt having an organic or metal cation, for example lithium bis(trifluoromethylsul fon yl)imide (Li TES I) OT lithium hexafluorophosphate, in an organic solvent, optionally propylene carbonate or a mixture of organic carbonates such as ethylene carbonate or diethyl carbonate.

Figure 2 illustrates a method of forming a battery device according to some embodiments of the present disclosure. The method comprises providing an anode current collector 107, depositing an insulating spacer 11 la over the anode current collector 107, depositing an adhesive 11 lb over the insulating spacer 111a, and providing an anode 101 over the anode current collector 107 in battery cell area Al. The cathode (not shown) is formed on a surface of the cathode current collector 109, either with or without the insulating spacer and / or adhesive. The current collector surfaces carrying the anode and cathode are brought together, with a separator provided between the anode and cathode, and the adhesive adheres the current collectors together with the insulating spacer preventing the cut-rent collectors from coming into direct contact.

In the embodiment of Figure 2, the insulating spacer and adhesive are applied over the anode current collector.

In other embodiments, the anode current collector 107 can be interchanged with the cathode current collector 109 so that the insulating spacer and adhesive arc applied to at least the cathode current collector. In other embodiments, the insulating spacer and adhesive are applied to both the anode and cathode current collectors.

A2 and A3 represent lead out tabs that are unitary with the anode current collector 107 and cathode current collector 109 respectively. In some embodiments, only one of the anode and cathode current collectors has a lead out tab which is unitary with its current collector. In some embodiments, neither the anode nor cathode current collector has a unitary lead out tab. If a current collector does not have a unitary lead out tab, a lead out may be electrically connected to the current collector by any suitable technique e.g. soldering or welding, e.g. ultrasonic welding. If an outer surface of a current collector is laminated with an insulator, e.g. a polymer layer, then the insulator may be removed in a connection area of the outer surface in order to connect the lead out.

hi Figure 2, formation of the unitary lead out tabs is in the final two production steps.

However, it will be understood that in some embodiments the lead outs can be formed from the anode current collector or cathode current collector in any step of the method of Figure 2.

In Figure 2, the method includes depositing an insulating spacer 111a over the anode current collector 107 and depositing an adhesive 111b over the insulating spacer 111a.

However, it will be understood that in some embodiments the method may comprise depositing an adhesive 111b over the anode current collector 107 or cathode current collector 109 and depositing the insulating spacer 111a over the adhesive 111b.

It will also be understood that in some embodiments, the adhesive 111b and the insulating spacer 11 la can be co-deposited over the anode current collector 107 or cathode current collector 109. It will be understood that the term co-deposition includes the preparation of an adhesive composition separate to the method of the present disclosure and arranging the adhesive composition as described in accordance with the embodiments of the present disclosure. The adhesive composition in this embodiment may be a sheet comprising the insulating spacer and the adhesive.

In Figure 2, the method includes providing an anode 101 over the anode current collector 107 after the insulating spacer 111a and the adhesive 111b are deposited. However, it will be understood that in some embodiments the anode 101 may be provided on the anode current collector 107 at any stage of production prior to adhesion of the anode current collector 107 and cathode current collector 109.

If the insulating spacer and adhesive are applied to the cathode current collector 109 then it will be understood that the cathode 105 may be formed on the cathode current collector before or after the insulating spacer and / or adhesive are deposited on the current collector.

In some embodiments, the anode 101 or cathode 105 may be provided over the anode current collector 107 or cathode current collector 109, respectively, before depositing the insulating spacer 111a and/or the adhesive 111b. In some embodiments, the anode 101 or cathode 105 may be provided after depositing a first one of the insulating spacer 111a and the adhesive 111b and before depositing the other of the insulating spacer 111a and/or the io adhesive 111b, respectively.

In some embodiments, there is a gap between the battery cell area and the adhesive area. In some embodiments, at least one of the insulating spacer and the adhesive is in contact with the battery cell. In some embodiments, the insulating spacer is in direct contact with the whole perimeter of the battery cell.

In some embodiments, at least one of the insulating spacer and the adhesive provide a well for depositing active materials into In some embodiments, the active materials are those used to form the battery cell. In some embodiments, the insulating spacer forms a hydrophobic barrier or well for depositing active materials into. In some embodiments, the porous matrix or mesh forms a well for containment of active materials. The porous matrix may have a hydrophobic surface to contain active material deposited into the well.

In some embodiments the insulating spacer or adhesive is treated, for example with SE6 plasma, to increase its hydrophobic properties. In the case of a polymer battery, one or both of an n-type polymer and a p-type polymer may be deposited from an ink comprising the active polymer using a coating or printing method. The insulating spacer may define a well for containment of the polymer or polymers.

The adhesive, insulating spacer and/or adhesive composition may be deposited by any suitable deposition method known to the skilled person including, without limitation, drop-casting, spraying, doctor blade coating, dip coating, lamination, screen printing and dispense printing. In dispense printing, a formulation is deposited in a continuous flow from a nozzle.

-I I-

In some embodiments, the method further comprises heating the adhesive following application of the second current collector over the adhesive.

Examples

Fabrication of an adhesive composition Nylon mesh was cut to 5 x 6 cm and placed on A3-sized sheet of siliconised paper. Hot adhesive was dispensed across the surface of the nylon mesh, ensuring complete coverage. The siliconised paper was folded over the glue covered-nylon, and the paper and nylon was pressed between two hotplates heated to 135 °C. The substrate was then passed through a laminator at 135 'V to squeeze the excess of hot glue out from the nylon mesh.

io The substrate was laid flat until the adhesive had cooled and solidified. The thermoplastic-nylon composition was removed from the siliconised paper substrate and the excess glue trimmed off with a sharp scalpel.

The resulting adhesive composition had a thickness of 162 pm with a thermoplastic loading of 11 mg/cm2 within the mesh. Thicker compositions of 250 pm have been obtained by excluding the laminator step.

The loading was measured by weighing the nylon mesh before and after thermoplastic deposition. The thickness was measured using a micrometer.

The spacer used was a hydrophilic nylon mesh with a 41.0 pm pore size, 33 pm wire diameter, and 50 pm thickness (sourced from PlastOk as a 158 cm roll; part number 0320 41/31).

The adhesive used was ethylene-vinyl acetate copolymer [EVA] with rosin ester tackifier glue sticks (melt temperature 135 °C) and was dispensed using a 25 W hot glue gun heatable to 195 °C.

Siliconised paper was used as a fabrication substrate.

Thermal sealing of current collectors Two Al/PET current collectors with lead-outs were cut with an active area of 42 x 45 mm. The themioplastic-nylon composition prepared was placed between the two Al/PET electrodes, with the Al side of each electrode contacting the adhesive composition. The device was placed between two sheets of siliconised paper and pressed between two hotplates heated to 135 °C for 10 s. The device was allowed to co& to room temperature while flat, before removing the siliconised paper substrate to give the model device.

The Al/PET current collectors consisted of AUPET foil with an 18 pm thick aluminium 5 foil with a 12 pm PET backing (sourced from All Foils).

The resistance between the two electrodes was measured using a multimeter. An overload reading was obtained, showing that the two electrodes are electrically isolated from one another.

The two electrodes were strongly bonded together and the resulting model device retained io a high degree of conformability.

Battery Example 1

Current collector preparation Aluminium with a PET backing (AUPET) was cold laminated to a Cricut cutting mat with the PET contacting the adhesive surface of the mat. A layer of pressure sensitive adhesive (PSA), cut to the same dimensions of the Al/PET, was cold laminated to the aluminium surface. A second layer of Al/PET, cut to the same dimensions as that of the first, was cold laminated to the PSA, with the PET backing contacting the PSA. The double laminate was carefully peeled off the Cricut mat and cut into a rectangle of 87.5 x 65 mm rectangle with a lead-out tab of 20 mm length x 10 mm width extending from one of the 87 nun length sides of the rectangle.

Anode composition formation 1.15 g of n-type Polymer 1, described below, and 439 mg of Super P carbon was ground in dry form in a mortar and pestle until homogeneous (approximately 5 minutes) 17 2 mL of a solution of sodium alginate (2 wt% in water: 2-butoxyethanol (95:5 v/v)) and BMP-TES' (81.8 pL) was added and the mixture was ground with a mortar and pestle until a smooth paste was obtained. The paste composition by weight was [n-type Polymer 1: Super P® Carbon Black: BMP-TFSI: Sodium Alginate] {56.07:21.49:5.60:16.80} with a total solid content of 11.9 wt%.

Cathode composition formation 933 mg of p-type Polymer 1, described below, and 373 mg of Super P carbon was ground in the dry form in a mortar and pestle until homogeneous (approximately 5 minutes). 28.0 mL of a solution of sodium alginate (2 wt% in water:2-butoxyethanol (95:5 v/v)) and BMP-TFSI (133.3 4) was added and the mixture was ground with a mortar and pestle until a smooth paste was obtained. The paste composition by weight was ip-type Polymer 1: Super 13® Carbon Black: BMP-TFST:Sodium Alginate] {45.45:18.19:9.09:27.27} with a total solid content of 7.3 wt%.

naype Polymer 1 A 3-necked round-bottomed flask, equipped with a magnetic stirrer. Dean-stark apparatus, condenser, nitrogen inlet and exhaust was charged with naphthalene-1,5-diamine (15 g, 94.8 mmol) and toluene (75 mL) Then terephthalaldehyde (12.7 g, 94.8 mmol) was taken in toluene (75 mL) and it was added to the reaction flask. The reaction was refluxed under Dean-Stark condition for 24 h with azeotropic water removal. The orange solid formed was recovered by filtration of the warm solution and dried to get 16 2 of crude material.

The solid was triturated with THE (160 ml) for 4 h at 28 °C. The solid was filtered and dried in a vacuum oven at 50 °C to afford 13 g of n-type Polymer 1 as an orange solid. CHN analysis: C: 82.82, H: 4.829: 10.78 (expected: C: 84.35, H: 4.72, N: 10.93).

n-type Polymer 1 p-type Polymer 1 A 2 L 3-necked round-bottomed flask, equipped with a mechanical stirrer, nitrogen inlet and exhaust. Triphenylamine (40 g, 0.163 mol) and Iron trichloride (79.4 g, 0.489 mmol) were charged to reaction flask and purged with nitrogen. Then degassed 1,2-dichloroethane was added (1200 mL) to the reaction mixture and it was heated to 85 °C for 48 h. Once cooled the reaction mixture was poured into the acetone (2 L) stirred for 30 mins The solid was filtered to afford 40 2 of crude material which was triturated with THE (1200 mL) at 28 'C overnight, filtered and triturared again with methanol (1200 ml) at 70 °C for 16 hours. The solid was recovered by filtration and dried in a vacuum oven at 50 °C to afford 30 g of p-type Polymer 1. CHN analysis C: 83.69, H: 5.26, N: 5.40 ( expected C: 89.23; H: 4.99; N: 5.78).

p-type Polymer 1 Anode and cathode deposition Before deposition, current collectors were rinsed with IPA and dried using a nitrogen gun.

Kapton tape (1.5 cm width) was used to secure the current collectors to the hotplate and define the active material area into which the electrode paste was to be dropcast. Electrode pastes were dispensed in a single step with an electronic pipette onto the current collectors. The paste was dried on the hotplate at 70 'C. The Kapton tape was then removed from the electrodes, and the electrodes were transferred to the glove box and /5 baked on a hotplate for 150 °C for 30 minutes to remove any residual moisture. Electrode loading (in mg/cm2) was determined by weighing the substrate before and after deposition of the electrode material.

For the anode, 1.9 mL of anode paste was dispensed onto the anode current collector to give a final electrode loading of 5.0 mg/cm-polymer per electrode.

For the cathode 3 1 mL of cathode paste was dispensed onto the cathode current collector to give a final electrode loading of 4.1 mg/cm2 polymer per electrode.

Separator formation 1.00 g of poly(ethylene oxide) (PEO, 100k), 1.0 mL of tetraglyme and 0.21 g of 4-methylbenzophenone (MBP) were mixed in a pestle and mortar at 120 °C until the PEO fully melted and a viscous liquid formed 20 mL of 1-butyl-1-methylpyrrolidinium bis(trifluoromethylsulfonyl)imide (BMP-TESI) was added, and the mixture was stirred until homogeneous.

The molten polymer mix was deposited in a line across the top of a 50 pm thick sheet of PET of approximately A4 size. A nylon mesh, cut to dimensions slightly smaller than that of the supporting PET substrate, was put on top of the nylon mesh. The PET-polymernylon-PET sandwich was pressed between two hot plates heated to 120 °C to melt the PEO mix for full penetration into the nylon mesh pores. The PET-polymer/nylon-PET sandwich was laminated at 100 'C. Once cooled, the PET-polymer-nylon-PET sandwich was cut in half to give two sandwiches approximately AS in size. Each AS sandwich was laminated again at 100 °C to ensure even distribution of the PEO mixture through the nylon. Without removing the PET sheets, the PEO film was cured using UV light (250 W UVH 255 hand lamp with an iron-doped metal halide lamp, intensity >80 mW cm-2) for 6 minutes either side under an inert, dry atmosphere. The resulting PEO/nylon composite was cut to size (6.75 x 4.5 cm rectangles) and stored in between the PET sheets in a glove box until required. To use, the PET backing sheets were peeled off. The films were measured to be between 40-65 pm thick.

Adhesive / spacer composition Hydrophilic nylon mesh with a 41.0 pm pore size, 33 pm wire diameter, 50 pm thickness was sourced from PlastOk was cut to 15 x 20 cm and placed on A3-sized sheet of siliconised paper. Hot TECBOND 261 EVA 12 mm flexible glue was dispensed from a glue. Double-sided silicone release paper was folded over the glue covered-nylon, and the paper and nylon pressed between two hotplates heated to 135 'V for 5 minutes. The composite was then laminated at 135 °C to squeeze the excess of hot glue out from the nylon mesh. The substrate was laid flat until the glue had cooled and solidified. The thermoplastic-nylon composite was removed from the paper substrate and the excess glue trimmed off with a scalpel. The heat-laminate-cool-trim steps were repeated a second time to ensure any excess glue was removed. The thermoplastic-nylon composite was cut to make a rectangular frame having an outer perimeter with dimensions of 75 mm x 97 5 mm and an inner perimeter with dimensions of 45 mm x 67.5 mm.

Battery fornzation Using a syringe, 0.5 mL of BMP-TFSI was dispensed dropwise across the active material surface on each anode and cathode, and the liquid was left to soak into the material. The thermoplastic-nylon composite frame was then placed on top of the cathode and bonded by placing on a hotplate set to 135 °C. The bonded structure was removed from the hotplate and allowed to cool to ambient temperature. The separator was placed over the cathode-adhesive spacer so that the cathode electrode material exposed by the adhesive spacer frame was completely covered. A second gel electrolyte separator was placed directly on top of the first. The stack was returned to the hotplate set to 135 °C, and the io edges of the gel electrolyte separators contacting the adhesive spacer were gently pressed to allow bonding. The stack was removed from the hotplate and the anode current collector carrying the anode was adhered while the adhesive was still hot to allow bonding. The entire stack was placed between a folded sheet of silicone paper and heated on a 135 °C hotplate for 1 minute, before being passed twice through a laminator at 135 ()C. The battery was cooled to ambient temperature before testing.

The battery was tested under ambient atmospheric conditions.

The battery was cycled on an Arbin Model -BT2043 battery tester with the following test method [active area = 25 cm2]: 1. CCCV charging step (0.2 mA/cm2 to 3 V, CV step until 0.04 mA/cm2 is reached) and constant current discharge at 0.2 mA/cm2 to 1 V. Repeat for 5 cycles.

2. CCCV charging step (1 mA/cm2 to 3 V, CV step until 0.2 mA/cm2 is reached) and constant current discharge at 1 mA/cm2 to 1 V. Repeat until the capacity falls below QT).

The mid-point voltage and charge capacity/cm2 were calculated for each cycle. The midpoint voltage is defined as the voltage at t/2, where t is the total discharge time of the battery for a given cycle. Charge capacity (expressed in units of mAh cm-2) is calculated as the time required to discharge to the end voltage multiplied by the cathodic current, and divided by the active area.

Results are shown in Figure 3 and 4.

The description above provides preferred exemplary embodiment(s) only, and is not intended to limit die scope, applicability or configuration of the invention. Rather, the ensuing description of the preferred exemplary embodiment(s) will provide those skilled in the art with an enabling description for implementing a preferred exemplary embodiment of the invention, it being understood that various changes may be made in the function and arrangement of elements, including combinations of features from different embodiments, without departing from the scope of the invention.

Unless the context clearly requires otherwise, throughout the description and the claims, the words "comprise," "comprising," and the like are to be construed in an inclusive sense, /0 as opposed to an exclusive or exhaustive sense; that is to say, in the sense of "including, but not limited to." As used herein, the terms "connected," "coupled." or any variant thereof means any connection or coupling, either direct or indirect, between two or more elements; the coupling or connection between the elements can be physical, logical, electromagnetic, or a combination thereof. Additionally, the words "herein," "above," "Mow," and words of similar import, when used in this application, refer to this application as a whole and not to any particular portions of this application. Where the context permits, words in the Detailed Description using the singular or plural number may also include the plural or singular number respectively. The word "or," in reference to a list of two or more items, covers all of the following interpretations of the word: any of the items in the list, all of the items in the list, and any combination of the items in the list.

The teachings of the technology provided herein can be applied to other systems, not necessarily die system described below. The elements and acts of die various examples described below can be combined to provide further implementations of the technology.

Some alternative implementations of the technology may include not only additional elements to those implementations noted below, but also may include fewer elements.

These and other changes can be made to the technology in light of the following detailed description. While the description describes certain examples of the technology, and describes the best mode contemplated, no matter how detailed the description appears, the technology can be practiced in many ways. Details of the system may vary considerably in its specific implementation, while still being encompassed by the technology disclosed herein. As noted above, particular terminology used when describing certain features or aspects of the technology should not be taken to imply that the terminology is being redefined herein to be restricted to any specific characteristics, features, or aspects of the technology with which that terminology is associated. In general, the terms used in the following claims should not be construed to limit the technology to the specific examples disclosed in the specification, unless die Detailed Description section explicitly defines such terms. Accordingly, the actual scope of the technology encompasses not only the disclosed examples, but also all equivalent ways of practicing or implementing the technology under the claims.

io To reduce the number of claims, certain aspects of the technology are presented below in certain claim forms, but the applicant contemplates the various aspects of the technology in any number of claim forms. For example, while some aspect of the technology may be recited as a computer-readable medium claim, other aspects may likewise be embodied as a computer-readable medium claim, or in other forms, such as being embodied in a means- /5 plus-function claim.

In the description above, for the purposes of explanation, numerous specific details are set forth in order to provide a thorough understanding of implementations of the disclosed technology. It will be apparent, however, to one skilled in the art that embodiments of the disclosed technology may be practiced without sonic of these specific details.

Claims

Claims: 1. A battery device comprising: a battery cell comprising an anode, a cathode and a separator between the anode and cathode, wherein, the battery cell is disposed in a battery area between a contact surface of an anode current collector and a contact surface of a cathode current collector; an adhesive composition is disposed in an adhesion area between the contact surface of the anode current collector and the contact surface of the cathode current collector; and the adhesive composition comprises an adhesive adhering the anode current ro collector to the cathode current collector and an insulating spacer spacing the anode cut-rent collector from the cathode current collector.
2. The battery device according to claim 1, wherein the insulating spacer is a porous matrix.
3. The battery device according to claim 2, wherein the porous matrix is a 15 mesh.
4. The battery device according to claim 2 herein the porous matrix is a polymer.
5. The battery device according to any of claims 2 to 4, wherein the adhesive is disposed in the pores of the porous matrix.
6. The battery device according to claim 1, wherein the insulating spacer is a plurality of insulating particles.
7. The battery device according to claim 6, wherein the insulating particles are selected from: ceramic particles; insulating polymer particles; and insulating particles comprising a getter material.
8. The battery device according to claim 7 wherein the insulating particles are elastic.
9. The battery device according to claim 7 or 8, wherein the insulating particles are dispersed in the adhesive.
10. The battery device according to any of the preceding claims, wherein the adhesive is a thermosetting adhesive.
11. The battery device according to any of claims 1-9, wherein the adhesive is a thermoplastic.
12. The battery device according to any of the preceding claims, wherein at least one of the anode current collector and cathode current collector comprises or consists of a layer of conductive material selected from a metal; a metal alloy; a conductive metal io oxide; a conducting polymer; or a conductive carbon allotrope.
13. The battery device according to any of the preceding claims, wherein the adhesion area surrounds the battery cell.
14. The battery device according to any of the preceding claims, wherein the battery device is a flexible battery device.
15. A method of producing a battery device according to any one of the preceding claims, comprising: providing the anode on the contact surface of the first current collector; providing the cathode on the contact surface of the second current collector; depositing the insulating spacer and the adhesive in the adhesion area on the contact surface of at least one of the first current collector and the second current collector; disposing the separator between the anode and cathode; and adhering together the contact surfaces of the first and second current collectors.
16. A method according to claim 15, wherein the insulating spacer is deposited before depositing the adhesive, or wherein the insulating spacer is deposited after depositing the adhesive, or wherein the insulating spacer and the adhesive are co-deposited.
17. A method according to claim 15 or 16, wherein the insulating spacer forms a porous matrix defining a well for containment of active materials.
18. A battery device manufactured by the method according to any one of claims 15 to 17.