Method for coating a battery cell

Abstract

To provide a cladding method to increase the stability and reliability of the bonding of an adhesive film with which a battery cell is clad.SOLUTION: A method for cladding a battery cell includes: contacting including adhesively bonding between an adhesive film and a bottom side U of the battery cell, the adhesive film including at least one crosslinkable adhesive layer and at least one carrier; contacting including adhesively bonding between the crosslinkable adhesive layer of the adhesive film and two side walls S1 and S2; contacting including adhesively bonding between the one crosslinkable adhesive layer of the adhesive film and two side walls S3 and S4; and contacting including adhesively bonding between the one crosslinkable adhesive layer of the adhesive film and one top side O of the battery cell. The carrier includes preferably an electrically insulating carrier having a specific volume resistivity of >1015 Ωcm, and the carrier includes preferably one or more materials selected from the group consisting of polypropylene, polyethylene terephthalate, polycarbonate and polyvinyl chloride.SELECTED DRAWING: Figure 1a

Description

Technical Field

[0001] The present invention relates to a method for coating a battery cell. Further, the present invention relates to a coated battery cell obtainable or obtained according to the method.

Background Art

[0002] For hybrid vehicles and electric vehicles, the stability and safety of the vehicle battery are critically important. The reliability of the insulating portion of the coating of the battery cell is an important factor affecting the stability and safety of the battery cell.

[0003] It is known that the driving environment of an automobile, which involves high temperature, high humidity, strong vibration, strong impact, etc., has many requirements. In such a harsh environment, the stability and reliability of the insulating portion of the battery cell are very important to avoid damage and connection errors that may lead to a short circuit of the battery.

[0004] In the case of battery cells for automobiles, the currently used insulation method is to wind and coat the battery cell with a pressure-sensitive adhesive tape for insulation. Generally, the adhesive strength of the pressure-sensitive adhesive tape is less than 1 MPa. Therefore, when this insulating pressure-sensitive adhesive layer is part of a composite manufactured using a relatively strong adhesive, the reliability of this pressure-sensitive adhesive tape is insufficient.

Prior Art Documents

Patent Documents

[0005]

Patent Document 1

Patent Document 2

Patent Document 3

Patent Document 4

Patent Document 5

Patent Document 6

Patent Document 7

Patent Document 8

Patent Document 9

Patent Document 10

Patent Document 11

Patent Document 12

Patent Document 13

Non-Patent Document

[0006]

Non-Patent Document 1

Summary of the Invention

Problems to be Solved by the Invention

[0007] Therefore, it is desirable to provide a method for coating a battery cell that avoids or significantly avoids the above-mentioned drawbacks of the previously described methods. In particular, in the method of the present invention, it is an object to enhance the adhesion stability and reliability of the adhesive film with which the battery cell is coated. Furthermore, the method of the present invention enables a highly reliable configuration of the battery assembly. That is, by the method of the present invention, a plurality of battery cells insulated with an insulating adhesive film can be structurally joined with an adhesive strength of more than 5 MPa.

Means for Solving the Problems

[0008] This problem is addressed by a method for coating a battery cell, having the features of the independent claims, and by a battery cell obtainable or obtained by this method. Advantageous developments, which can be realized individually or in combination, are presented in the description and the dependent claims.

[0009] Accordingly, the present invention relates to a method for coating a battery cell. The method comprises the steps detailed below. These steps can be carried out in the order described. In particular, steps (i) to (iv) are carried out in this (temporary) order. In one variant of the method according to the invention, the order of sub-steps (v) and (vi) is reversed. That is, preferably, the method first carries out steps (i) to (iv), and then steps (v) and (vi) follow, or vice versa steps (vi) and (v).

[0010] That is, the method according to the invention starts with step (i), then carries out step (ii), then step (iii), then step (iv). Subsequently, step (v) and then step (vi) can be carried out, or in one alternative, first step (vi) and then step (v) can be carried out.

[0011] At least one step of said crosslinking can be carried out after steps (ii) to (vi). Furthermore, one or more of said process steps can be carried out once or repeatedly. The method can comprise still further process steps in addition to the steps described above.

[0012] Accordingly, the present invention is a method for coating a battery, comprising (i) providing a battery cell, comprising at least two opposing side walls S1 and S2, at least two opposing side walls S3 and S4, at least one lower surface U, and at least one upper surface O; (ii) providing a film, comprising providing an adhesive film including at least one crosslinkable adhesive layer and at least one carrier; (iii) contacting the adhesive film of (ii) with the at least one lower surface U of the battery cell of (i), the contacting including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least one lower surface U of the battery cell; (iv) contacting the adhesive film with the at least two side walls S1 and S2, the contacting including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least two side walls S1 and S2; (v) contacting the adhesive film with the at least two side walls S3 and S4, the contacting including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least two side walls S3 and S4; (vi) contacting the adhesive film with the at least one upper surface O, the contacting including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least one upper surface O of the battery cell; comprising further comprising at least one step of at least partial crosslinking of the crosslinkable adhesive layer, wherein the at least one step of crosslinking can be performed after the steps from (ii) to (vi), relating to the method.

[0013] Preferably, the at least one step of crosslinking is performed after the step of (ii) or after the step of (vi).

[0014] Preferably, the carrier comprises an insulating carrier, preferably an electrically insulating carrier, more preferably an electrically insulating carrier having a specific volume resistance of > 10 15 Ωcm, preferably > 10 16 Ωcm, more preferably > 10 17 Ωcm, as determined in accordance with DIN EN 62631-3-1 (VDE 0307-3-1): 2017-01.

[0015] Preferably, the carrier comprises one or more materials selected from the group consisting of polyimide, polybenzimidazole, polyamideimide, polyetherimide, polyacetal, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, polyamide 6, ultra-high molecular weight polyethylene, polypropylene, vinyl chloride resin, polystyrene, polyethylene terephthalate, acrylonitrile butadiene styrene, polycarbonate, polyvinyl chloride, ethylene vinyl acetate, and polyester; more preferably, the group consisting of polypropylene, polyethylene terephthalate, polycarbonate, and polyvinyl chloride; even more preferably, the group consisting of polypropylene and polyethylene terephthalate.

[0016] Basically, there is no particular limitation on the thickness of the carrier. Preferably, the carrier has a thickness in the range of 20 to 100 μm, more preferably in the range of 30 to 90 μm, even more preferably in the range of 45 to 75 μm.

[0017] Basically, there is no particular limitation on the thickness of the crosslinkable adhesive layer. Preferably, the crosslinkable adhesive layer has a thickness in the range of 10 to 150 μm, more preferably in the range of 10 to 100 μm, even more preferably in the range of 20 to 60 μm.

[0018] Preferably, the crosslinkable adhesive layer contains a crosslinkable pressure-sensitive adhesive. Preferably, the crosslinkable pressure-sensitive adhesive has an adhesive force to steel of at least 1 N / cm in the uncrosslinked state as determined according to Test Method 2.

[0019] Preferably, the crosslinkable pressure-sensitive adhesive is crosslinkable by radiation having a wavelength in the range of 10 to 800 nm, more preferably by radiation having a wavelength in the range of 200 to 500 nm, even more preferably by radiation having a wavelength in the range of 350 nm to 485 nm, and even more preferably by radiation from an LED light source having an emission maximum in the range of 350 nm to 485 nm.

[0020] Preferably, the crosslinkable pressure-sensitive adhesive comprises at least one polymer, at least one epoxy resin, and at least one photoinitiator.

[0021] Preferably, the crosslinkable pressure-sensitive adhesive (a) from 25 to 75% by weight, preferably from 30 to 70% by weight of at least one polymer; (b) from 20 to 70% by weight, preferably from 30 to 65% by weight of at least one epoxy resin; (c) from 0.01 to 5% by weight, preferably from 1 to 4% by weight of at least one cationic photoinitiator; and comprises.

[0022] Preferably, the at least one polymer comprises one or more materials selected from the group consisting of polyacrylate, polyurethane, poly(ethylene) vinyl acetate copolymer, poly(ethylene) vinyl acetate copolymer, nitrile rubber, and polyacrylate block copolymer, and more preferably, selected from the group consisting of polyacrylate, poly(ethylene) vinyl acetate copolymer, and polyacrylate block copolymer.

[0023] Those functionalized with functional groups such as acid anhydride, acid, epoxide, hydroxy, siloxane, oxazoline are also understood as polymers.

[0024] Preferably, the at least one epoxy resin comprises at least one epoxy resin E1 and at least one epoxy resin E2.

[0025] Preferably, epoxy resin E1 comprises a solid or highly viscous epoxy resin E1 at 25°C, and epoxy resin E2 comprises a liquid epoxy resin E2 at 25°C.

[0026] In line with the understanding of those skilled in the art, epoxy resins are compounds having at least one oxirane group. These can be aromatic or aliphatic, especially cycloaliphatic in nature. Epoxy resins can include not only monomeric epoxy resins but also oligomeric or polymeric epoxy resins. Polymeric epoxy resins often have, on average, at least two epoxy groups per molecule, especially more than two epoxy groups per molecule.

[0027] Preferably, the at least one epoxy resin E1 and / or the at least one epoxy resin E2, preferably the at least one epoxy resin E1 and the at least one epoxy resin E2, are selected from the group consisting of epoxy compounds having two or more epoxy groups, preferably two epoxy groups.

[0028] Oligomeric or polymeric epoxy resins include substantially linear polymers having terminal epoxy groups (e.g., diglycidyl ethers of polyoxyalkylene glycols), polymers having skeletal oxirane units (e.g., polybutadiene-polyepoxides), and polymers having epoxy side groups (e.g., glycidyl methacrylate polymers or -copolymers). The molecular weight of such epoxy resins can vary from 58 to about 100,000 g / mol or more, where the molecular weight is a significant adjustment variable for the regulation of kinematic viscosity. Exemplary polymerizable epoxy resins include epoxycyclo - hexanecarboxylates, such as 4 - epoxycyclohexylmethyl - 3,4 - epoxycyclohexanecarboxylate, 3,4 - epoxy - 2 - methylcyclohexylmethyl - 3,4 - epoxy - 2 - methylcyclohexanecarboxylate, and bis(3,4 - epoxy - 6 - methylcyclohexylmethyl) adipate. Further examples of polymerizable epoxy resins are disclosed, for example, in US 3,117,099 A (Patent Document 1). Still another polymerizable epoxy compound particularly useful in the practice of the present invention includes glycidyl ether monomers such as those disclosed in US 3,018,262 (Patent Document 2). Examples are glycidyl ethers of polyhydric phenols (e.g., diglycidyl ether of 2,2 - bis-(2,3 - epoxypropoxyphenol) propane) obtained by the reaction of polyhydric phenols with an excess of chlorohydrin, such as epichlorohydrin. In particular, glycidyl ethers of bisphenols, such as bisphenol - A (4,4’-(propane - 2,2 - diyl)diphenol) and bisphenol - F (bis(4 - hydroxyphenyl)methane), can be mentioned. Such reaction products are commercially available in various molecular weights and aggregation states (e.g., so - called type 1 to type 10 BADGE resins). Typical examples of liquid bisphenol - A - diglycidyl ether are Epikote 828, D.E.R. 331, and Epon 828. Typical solid BADGE resins are Araldite GT6071, GT7072, Epon 1001, and D.E.R. 662.Another reaction product of phenols and epichlorohydrin is phenolic- and cresol novolak resins, such as the Epiclon type or Araldite EPN and ECN types (e.g., ECN1273).

[0029] Preferably, the at least one epoxy resin E1 and / or the at least one epoxy resin E2, preferably the at least one epoxy resin E1 and the at least one epoxy resin E2, is selected from the group consisting of epoxy compounds having at least one cycloaliphatic group, preferably a cyclohexyl group or a dicyclopentadienyl group. More preferably, additionally or alternatively, the at least one epoxy resin E1 and / or the at least one epoxy resin E2, preferably the at least one epoxy resin E1 and the at least one epoxy resin E2, is selected from the group consisting of bisphenol-A-diglycidyl ether and bisphenol-F-diglycidyl ether, preferably bisphenol-A-diglycidyl ether.

[0030] Preferably, determined according to test method 3, the at least one epoxy resin E1 has a Tg of ≧25 °C, and the at least one epoxy resin E2 has a Tg of <25 °C.

[0031] Preferably, determined according to test method 4, the at least one epoxy resin E1 has a kinematic viscosity of 100 Pa s or more, more preferably 150 Pa s or more, at 25 °C.

[0032] Preferably, determined according to test method 4, the at least one epoxy resin E2 has a kinematic viscosity of 30 Pa s or less, more preferably 20 Pa s or less, even more preferably 10 Pa s or less, at 25 °C.

[0033] Preferably, the epoxy resin E1 is selected from the group consisting of compounds that are solid substances or highly viscous substances at 25°C, where the latter is defined within the framework of the present invention by the lower limit of the kinematic viscosity at 25°C. In this regard, the person skilled in the art understands that this distinction between solid substances and corresponding highly viscous substances is reasonable in practical use, since the viscosity of solid substances is essentially several orders of magnitude higher than the above-mentioned value of kinematic viscosity, but in practice it often makes little sense to determine it, and therefore it is sufficient to confirm that it is a solid substance. An advantage of the selected definition is that there is no need to distinguish whether a substance is a solid substance at 25°C or a highly viscous substance with the corresponding kinematic viscosity. In contrast, the polymerizable epoxide E2 is a low-viscosity liquid defined within the framework of the present invention by the upper limit of the kinematic viscosity at 25°C. At this time, within the framework of the present invention, the kinematic viscosity is determined at 25°C at a shear rate of 1 s -1 in accordance with DIN53019-1 of the 2008 edition.

[0034] At this time, it is advantageous if the viscosity difference between the epoxy resin E1 and the epoxy resin E2 is selected to be relatively large. Therefore, at 25°C, at least one epoxy resin E1 having a kinematic viscosity of 100 Pa s or more, preferably 150 Pa s or more, is preferred. At 25°C, at least one epoxide E2 having a kinematic viscosity of 30 Pa s or less, preferably 20 Pa s or less, and particularly preferably 10 Pa s or less, is more preferred. At this time, particularly preferably, these corresponding preferred ranges are combined with each other.

[0035] Preferably, the at least one epoxy resin E1 has a softening temperature of 45°C or higher as determined according to test method 5.

[0036] In this regard, it is more preferable when both of the above characteristics of the epoxy resin are combined such that the epoxy resin having at least one alicyclic group is obtained by hydrogenation of the corresponding bisphenol compound. Therefore, the at least one epoxy resin E1 and / or the at least one epoxy resin E2, preferably the at least one epoxy resin E1 and the at least one epoxide resin E2, are particularly preferably selected from the group consisting of hydrogenated bisphenol-A-diglycidyl ether and hydrogenated bisphenol-F-diglycidyl ether, preferably hydrogenated bisphenol-A-diglycidyl ether. More preferably, the epoxy resin E2 is selected from the group consisting of hydrogenated bisphenol-A-diglycidyl ether and hydrogenated bisphenol-F-diglycidyl ether, preferably hydrogenated bisphenol-A-diglycidyl ether.

[0037] From the above description, it is also inferred that the use of the solid epoxy resin E1 is particularly preferable due to the resulting large discrepancy in kinematic viscosity. Therefore, at least one epoxy resin E1 as a solid having a softening temperature of 45 °C or higher is more preferable.

[0038] Preferably, E1:E2 is in the range from 10:1 to 1:10, more preferably in the range from 4:1 to 1:4.

[0039] Preferably, the at least one photoinitiator includes one or more materials selected from the group consisting of systems based on sulfonium, iodonium and metallocene.

[0040] Examples of sulfonium-based cations include those described in US6908722B1 (Patent Document 3). Examples of anions useful as counterions for the above cations include tetrafluoroborate, tetraphenylborate, hexafluorophosphate, perchlorate, tetrachlorophenylate, hexafluoroarsenate, hexafluoroantimonate, pentafluoro-hydroxyantimonate, hexachloroantimonate, tetrakispentafluorophenylborate, tetrakis(pentafluoromethylphenyl)borate, bis(trifluoromethylsulfonyl)amide, and tris(trifluoromethylsulfonyl)methide. In addition, especially for iodonium-based initiators, chloride ion, bromide ion or iodide ion can also be considered as an anion. However, in this case, initiators essentially free of chlorine and bromine are preferred. A capable example of such a system is, for example, triphenylsulfonium hexafluoroantimonate. Still another suitable initiator is disclosed, for example, in US3,729,313A (Patent Document 4), US3,741,769A (Patent Document 5), US4,250,053A (Patent Document 6), US4,394,403A (Patent Document 7), US4,231,951A (Patent Document 8), US4,256,828A (Patent Document 9), US4,058,401A (Patent Document 10), US4,138,255A (Patent Document 11) and US2010 / 063221A1 (Patent Document 12).

[0041] Specific examples of usable sulfonium salts are triphenylsulfonium hexafluoroarsenate, triphenylsulfonium hexafluoroborate, triphenylsulfonium tetrafluoroborate, triphenylsulfonium tetrakis(pentafluorobenzyl)borate, methyldiphenylsulfonium tetrafluoroborate, methyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, dimethylphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluorophosphate, triphenylsulfonium hexafluoroantimonate, diphenylnaphthylsulfonium hexafluoroarsenate, tritolylsulfonium hexafluorophosphate, anisildiphenylsulfonium hexafluoroantimonate, 4-butoxyphenyldiphenylsulfonium tetrafluoroborate, 4-chlorophenyldiphenylsulfonium hexafluoroantimonate, tris(4-phenoxyphenyl)sulfonium hexafluorophosphate, di(4-ethoxyphenyl)methylsulfonium hexafluoroarsenate, 4-acetylphenyldiphenylsulfonium tetrafluoroborate, 4-acetylphenyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, tris(4-thiomethoxyphenyl)sulfonium hexafluorophosphate, di(methoxysulfonylphenyl)methylsulfonium hexafluoroantimonate, di(methoxynaphthyl)methylsulfonium tetrafluoroborate, di(methoxynaphthyl)methylsulfonium tetrakis(pentafluorobenzyl)borate, di(carbomethoxyphenyl)methylsulfonium hexafluorophosphate, (4-octyloxyphenyl)diphenylsulfonium tetrakis(3,5-bis-trifluoromethylphenyl)borate, tris[4-(4-acetylphenyl)thiophenyl]sulfonium tetrakis(pentafluorophenyl)borate, tris(dodecylphenyl)sulfonium tetrakis(3,5-bis-trifluoromethylphenyl)borate, 4-acetamidophenyldiphenylsulfonium tetrafluoroborate, 4-acetamidophenyldiphenylsulfonium tetrakis(pentafluoro-benzyl)borate, dimethylnaphthylsulfonium hexafluorophosphate, trifluoromethyldiphenyl-sulfonium tetrafluoroborate, trifluoromethyldiphenylsulfonium tetrakis(pentafluorobenzyl)borate, phenylmethylbenzylsulfonium hexafluorophosphate, 5-methylthianthrenium hexa-fluorophosphate, 10-phenyl-9,9-dimethylthioxanthenium hexafluorophosphate, 10-phenyl-9-oxothioxanthenium tetrafluoroborate, 10-phenyl-9-oxothioxanthenium tetrakis(pentafluoro-benzyl)borate, 5-methyl-10-oxothianthrenium tetrafluoroborate, 5-methyl-10-oxothianthrenium tetrakis(pentafluorobenzyl)borate, and 5-methyl-10,10-dioxothianthrenium hexafluorophosphate.,

[0042] Specific examples of usable iodonium salts are diphenyliodonium tetrafluoroborate, di-(4-methylphenyl)-iodonium tetrafluoroborate, phenyl-4-methylphenyl iodonium tetrafluoroborate, di-(4-chlorophenyl)-iodonium hexafluorophosphate, dinaphthyliodonium tetrafluoroborate, di-(4-trifluoromethylphenyl)-iodonium tetrafluoroborate, diphenyliodonium hexafluorophosphate, di-(4-methylphenyl)-iodonium hexafluorophosphate, diphenyliodonium hexafluoroarsenate, di-(4-phenoxyphenyl)-iodonium tetrafluoroborate, phenyl-2-thienyl iodonium hexafluorophosphate, 3,5-dimethylpyrazolyl-4-phenyl iodonium hexafluorophosphate, diphenyliodonium hexafluoroantimonate, 2,2'-diphenyliodonium tetrafluoroborate, di-(2,4-dichlorophenyl)-iodonium hexafluorophosphate, di-(4-bromophenyl)-iodonium hexafluorophosphate, di-(4-methoxyphenyl)-iodonium hexafluorophosphate, di-(3-carboxyphenyl)-iodonium hexafluorophosphate, di-(3-methoxycarbonylphenyl)-iodonium hexafluorophosphate, di-(3-methoxysulfonylphenyl)-iodonium hexafluorophosphate, di-(4-acetamidophenyl)-iodonium hexafluorophosphate, di-(2-benzothienyl)-iodonium hexafluorophosphate, diaryliodonium tris(trifluoromethylsulfonyl)methide, for example diphenyliodonium hexafluoroantimonate, diaryliodonium tetrakis-(pentafluorophenyl)-borate, for example diphenyliodonium tetrakis-(pentafluorophenyl)-borate, [4-(2-hydroxy-n-tetradecyloxy)-phenyl]-phenyl iodonium hexafluoroantimonate, [4-(2-hydroxy-n-tetradecyloxy)-phenyl]-phenyl iodonium trifluoromethanesulfonate,[4-(2-Hydroxy-n-tetradecyloxy)-phenyl]-phenyl iodonium hexafluorophosphate, [4-(2-hydroxy-n-tetradecyloxy)-phenyl]-phenyl iodonium tetrakis-(pentafluorophenyl)-borate, bis-(4-tert-butylphenyl)-iodonium hexafluoroantimonate, bis-(4-tert-butylphenyl)-iodonium hexafluorophosphate, bis-(4-tert-butylphenyl)-iodonium trifluoromethanesulfonate, bis-(4-tert-butylphenyl)-iodonium tetrafluoroborate, bis-(dodecylphenyl)-iodonium hexafluoroantimonate, bis-(dodecylphenyl)-iodonium tetrafluoroborate, bis-(dodecylphenyl)-iodonium hexafluorophosphate, bis-(dodecylphenyl)-iodonium trifluoromethylsulfonate, di-(dodecylphenyl)-iodonium hexafluoroantimonate, di-(dodecylphenyl)-iodonium triflate, diphenyliodonium bisulfate, 4,4'-dichlorodiphenyliodonium bisulfate, 4,4'-dibromodiphenyliodonium bisulfate, 3,3'-dinitrodiphenyliodonium bisulfate, 4,4'-dimethyldiphenyliodonium bisulfate, 4,4'-bis-succinimidodiphenyliodonium bisulfate, 3-nitrodiphenyliodonium bisulfate, 4,4'-dimethoxydiphenyliodonium bisulfate, bis-(dodecylphenyl)-iodonium tetrakis-(pentafluorophenyl)-borate, (4-octyloxyphenyl)-phenyl iodonium tetrakis-(3,5-bis-trifluoromethylphenyl)-borate and (trityl cumyl)-iodonium tetrakis-(pentafluorophenyl)-borate, and ferrocenium salts (e.g. EP0542716B1 (Patent Document 13)), for example η5-(2,4-cyclopentadien-1-yl)-[(1,2,3,4,5,6,9)-(1-methylethyl)-benzene]-iron.,

[0043] Photoinitiators are typically used individually or as a combination of two or more photoinitiators. When using photoinitiators, a combination with so-called sensitizers for adapting the activation wavelength of the photoinitiating system to the selected emission spectrum is very useful, and in this regard, reference is made to the literature known to those skilled in the art, for example, A.W. Green, “Industrial Photoinitiators: A technical guide”, 2010 (Non-Patent Document 1).

[0044] Preferably, the crosslinkable pressure-sensitive adhesive additionally (d) at least one elastomer-modified epoxide E3 from 3 to 30% by weight, more preferably from 5 to 20% by weight, still more preferably from 7 to 15% by weight, based on the total weight percentage of said at least one polymer and said at least one epoxy resin, is included.

[0045] Preferably, said at least one elastomer-modified epoxide E3 comprises one or more materials selected from the group consisting of carboxy-terminated nitrile rubber, carboxy-terminated butadiene rubber, epoxy-terminated butadiene rubber, epoxy-terminated nitrile rubber, epoxy-functionalized polyurethane, polyester and polyether.

[0046] The elastomer-modified epoxide E3 in the meaning of the present invention is understood to be an epoxide, especially liquid and usually highly viscous, having an average functionality of at least 2 and an elastomer content of up to 50% by weight, in particular from 5 to 40% by weight. The epoxy groups can be arranged at the ends and / or in the side chains of the molecule. The elastomer structural part of these flexible epoxides is composed of polyenes, diene copolymers and polyurethanes, especially polybutadiene, butadiene-styrene copolymer or butadiene-acrylonitrile copolymer.

[0047] Epoxy resin E3 modified with butadiene-acrylonitrile copolymer (nitrile rubber) is, for example, an epoxide prepolymer, which is obtained by modifying an epoxy resin having at least two epoxy groups in the molecule with nitrile rubber. As the epoxide base, preferably, the reaction product of glycerin or polyethylene glycol with a halogen-containing epoxide compound, such as epichlorohydrin, or the reaction product of a polyhydric phenol, such as hydroquinone, bisphenol A and a halogen-containing epoxide is used. The reaction product from a bisphenol A type epoxy resin having two terminal epoxy groups is desirable.

[0048] For the bonding of epoxy resin E3, in the case of a butadiene polymer or a butadiene-acrylonitrile copolymer (so-called nitrile rubber), a third monomer having an acid functional group, such as acrylic acid, can be polymerized together, whereby a so-called carboxy-terminated nitrile rubber (CTBN) is obtained. Usually, these compounds contain acid groups not only at the ends but also along the main chain. CTBN is sold, for example, under the trade name Hycar by B.F.Goodrich. These have a molar mass between 2000 and 5000 and an acrylonitrile content between 10% and 30%. Specific examples are Hycar CTBN1300×8, 1300×13 or 1300×15. Accordingly, the reaction with the butadiene polymer proceeds.

[0049] By the reaction of epoxy resin and CTBN, a so-called epoxy-terminated nitrile rubber (ETBN) is obtained, which is particularly preferably used in the present invention. Commercially, such ETBN can be obtained, for example, from Emerald Materials under the names HYPRO ETBN (still Hycar ETBN), such as Hypro 1300X40ETBN Hypro 1300X63ETBN and Hypro 1300X68ETBN. An example of an epoxy-terminated butadiene rubber is Hypro 2000X174ETB.

[0050] A further example of the elastomer-modified epoxy-terminated epoxide E3 is the reaction product of the diglycidyl ether of neopentyl alcohol and a carboxy-terminated butadiene / acrylonitrile-elastomer (e.g., EPON TM Resin 58034) from Resolution Performance Products LLC, the reaction product of the diglycidyl ether of bisphenol-A and a carboxy-terminated butadiene / acrylonitrile elastomer (e.g., EPON TM Resin 58006) from Resolution Performance Products LLC, the reaction product of the diglycidyl ether of bisphenol-A and a butadiene / acrylonitrile elastomer having a carboxyl terminus (e.g., CTBN-1300X8 and CTBN-1300X13 from Noveon, Inc. (Cleveland, Ohio)), and the reaction product of the diglycidyl ether of bisphenol-A and a butadiene / acrylonitrile elastomer having an amine terminus (e.g., ATBN-1300X16 and ATBN-1300X42 from Noveon, Inc.). An example of the elastomer-modified epoxide resin adduct is the reaction product of a bisphenol-F-based epoxy resin and a butadiene / acrylonitrile elastomer having a carboxyl terminus (e.g., EPON TM Resin 58003) from Resolution Performance Products LLC.

[0051] Preferably, the at least two opposing sidewalls S1 and S2 include at least two surfaces F1 and F2, where sidewall S1 includes surface F1 and sidewall S2 includes surface F2. Preferably, surfaces F1 and F2 have the same width.

[0052] Preferably, the at least two opposing sidewalls S3 and S4 include at least two surfaces F3 and F4, where sidewall S3 includes surface F3 and sidewall S4 includes surface F4.

[0053] Preferably, surfaces F3 and F4 have the same area. Preferably, surfaces F1 and F2 are wider than surfaces F3 and F4.

[0054] Preferably, the battery cell is rectangular.

[0055] Preferably, the upper surface O includes battery contacts. In one variation of the present invention, side walls S3 and S4 each have a battery contact.

[0056] Preferably, the lower surface U is on the opposite side of the upper surface O.

[0057] Preferably, the at least partial crosslinking of the crosslinkable adhesive layer is carried out after step (ii).

[0058] Preferably, the at least partial crosslinking of the crosslinkable adhesive layer is carried out after step (vi).

[0059] Preferably, in (ii), the adhesive film is provided in the form of an adhesive film web wound around a roll.

[0060] Preferably, (iii) is (iii.1) unwinding of the adhesive film from the roll and, simultaneously therewith, crosslinking of the crosslinkable adhesive layer by radiation having a wavelength in the range from 10 to 800 nm, preferably radiation having a wavelength in the range from 200 to 500 nm, more preferably radiation having a wavelength in the range from 350 nm to 485 nm, even more preferably radiation from an LED light source having an emission maximum in the range from 350 nm to 485 nm, and includes.

[0061] Preferably, the adhesive film has a width b and a length l.

[0062] Preferably, in step (iii), the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount up to surface Δb1.

[0063] Preferably, in step (iv), the length l of the adhesive film protrudes from the upper surface O of the battery cell by an amount corresponding to the surface Δl1.

[0064] Preferably, in step (iv), the width b of the adhesive film protrudes from at least two opposite side walls S1 and S2 of the battery cell by an amount corresponding to the surface Δb2, where Δb2 < Δb1.

[0065] Preferably, in step (iv), the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount corresponding to the surface Δb3, where Δb3 < Δb2 < Δb1.

[0066] Preferably, (iv) comprises (iv.1) providing an adhesive device including at least one pressing roller; (iv.2) guiding the at least one pressing roller onto the side wall S1 and / or side wall S2, including adhering the adhesive layer of the adhesive film to the side wall S1 and / or side wall S2 (preferably by pressing the adhesive layer of the adhesive film using the pressing roller); and includes.

[0067] Preferably, (v) comprises (v.1) attaching Δb3 onto at least two side walls S3 and S4, including adhering the adhesive layer of the adhesive film to the at least two side walls S3 and S4; (v.2) attaching Δb2 onto at least two side walls S3 and S4, including adhering the adhesive layer of the adhesive film to the at least two side walls S3 and S4 with the formation of the surface Δl2, where Δl2 < Δl1; and includes.

[0068] Preferably, (vi) comprises (vi.1) attaching Δl2 onto the upper surface O of the battery cell, including adhering the adhesive layer of the adhesive film to the at least one upper surface O with the formation of the surface Δl3, where Δl3 < Δl2; (vi.2) Applying Δl3 to the upper surface O of the battery cell, including adhesion between the adhesive layer of the adhesive film and the at least one upper surface O; including.

[0069] According to another possible embodiment of the present invention, the method for covering a battery comprises the following steps: (i) Providing a battery cell, including a battery cell having at least two opposite side walls S1 and S2, at least two opposite side walls S3 and S4, at least one lower surface U, and at least one upper surface O; (ii) Providing an adhesive film with a width b and a length l, including an adhesive film having at least one crosslinkable adhesive layer and at least one carrier; (iii) Contacting the adhesive film of (ii) with the at least one lower surface U of the battery cell of (i), including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least one lower surface U of the battery cell, where the width b of the adhesive film protrudes by Δb1 from the lower surface U of the battery cell; (iv) Contacting the adhesive film with the at least two side walls S1 and S2, including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S1 and S2, where the width b of the adhesive film protrudes by a surface Δb2 from the at least two opposite side walls S1 and S2 of the battery cell, and Δb2 < Δb1; (v) Contacting the adhesive film with the at least two side walls S3 and S4, including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S3 and S4, where the width b of the adhesive film protrudes by a surface Δb3 from the at least two opposite side walls S3 and S4 of the battery cell, and Δb3 < Δb1; (v.1) Applying Δb3 to the at least two side walls S3 and S4, including adhesion between the adhesive layer of the adhesive film and the at least two side walls S3 and S4; (v.2) Affixing Δb2 onto the at least two sidewalls S3 and S4, including adhesion of the adhesive layer of the adhesive film to the at least two sidewalls S3 and S4 accompanied by the formation of surface Δl2, where Δl2 < Δl1; (vi) Contact of the adhesive film with the at least one upper surface O, including adhesion of the at least one crosslinkable adhesive layer of the adhesive film to the at least one upper surface O of the battery cell; (vi.1) Affixing Δl2 onto the upper surface O of the battery cell, including adhesion of the adhesive layer of the adhesive film to the at least one upper surface O accompanied by the formation of surface Δl3, where Δl3 < Δl2; (vi.2) Affixing Δl3 onto the upper surface O of the battery cell, including adhesion of the adhesive layer of the adhesive film to the at least one upper surface O; including further including at least one step of at least partial crosslinking of the crosslinkable adhesive layer, where at least one step of this crosslinking is performed after the step of (ii) or after the step of (vi).

[0070] Furthermore, the present invention relates to a coated battery cell obtainable or obtained by the method described herein.

[0071] The present invention described above is further described by the following sets of embodiments and combinations of embodiments, where this combination is given by the appropriate subordinate and citation relationships. In particular, with respect to expressions such as "the method according to any one of Embodiments 1 to 5", at the places where the scope of the embodiment is described, it is pointed out that the individual embodiments within this scope are explicitly disclosed to those skilled in the art, that is, this expression is understood by those skilled in the art to be synonymous with the expression "the method according to any one of Claims 1, 2, 3, 4, and 5". Furthermore, it is explicitly pointed out that the following sets of embodiments do not represent a set of patent claims determining the scope of protection, but rather represent appropriately configured parts of the detailed description of the invention describing the general and preferred aspects of the present invention.

[0072] 1. A method for coating a battery cell, the steps of which are: (i) providing a battery cell including at least two opposing side walls S1 and S2, at least two opposing side walls S3 and S4, at least one lower surface U, and at least one upper surface O; (ii) providing an adhesive film including at least one crosslinkable adhesive layer and at least one carrier; (iii) contacting the adhesive film of (ii) with at least one lower surface U of the battery cell of (i), the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least one lower surface U of the battery cell; (iv) contacting the adhesive film with the at least two side walls S1 and S2, the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S1 and S2; (v) contacting the adhesive film with the at least two side walls S3 and S4, the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S3 and S4; (vi) contacting the adhesive film with the at least one upper surface O, the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least one upper surface O of the battery cell; comprising further comprising at least one step of at least partial crosslinking of the crosslinkable adhesive layer, wherein the at least one step of crosslinking can be carried out after the steps from (ii) to (vi), said method.

[0073] 2. The carrier is an insulating carrier, preferably an electrical insulating carrier, more preferably determined in accordance with DIN EN62631-3-1 (VDE 0307-3-1): 2017-01 to be > 10 15 Ωcm, preferably > 10 16Ω cm, more preferably > 10 17 The method according to Embodiment 1, comprising an electrically insulating carrier having a specific volume resistivity of 17 Ω cm.

[0074] 3. The method according to Embodiment 1 or 2, wherein the carrier comprises one or more materials selected from the group consisting of polyimide, polybenzimidazole, polyamideimide, polyetherimide, polyacetal, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, polyamide 6, ultra-high molecular weight polyethylene, polypropylene, vinyl chloride resin, polystyrene, polyethylene terephthalate, acrylonitrile-butadiene-styrene, polycarbonate, polyvinyl chloride, ethylene-vinyl acetate, and polyester, preferably from the group consisting of polypropylene, polyethylene terephthalate, polycarbonate, and polyvinyl chloride, and more preferably from the group consisting of polypropylene and polyethylene terephthalate.

[0075] 4. The method according to any one of Embodiments 1 to 3, wherein the carrier has a thickness in the range of 20 to 100 μm, preferably in the range of 30 to 90 μm, and more preferably in the range of 40 to 75 μm.

[0076] 5. The method according to any one of Embodiments 1 to 4, wherein the crosslinkable adhesive layer has a thickness in the range of 10 to 150 μm, preferably in the range of 10 to 100 μm, and more preferably in the range of 20 to 60 μm.

[0077] 6. The method according to any one of Claims 1 to 5, wherein the crosslinkable adhesive layer comprises a crosslinkable pressure-sensitive adhesive, and the crosslinkable pressure-sensitive adhesive has an adhesive force to steel of at least 1 N / cm in the uncrosslinked state as determined according to Test Method 2.

[0078] 7. The method according to embodiment 6, wherein the crosslinkable pressure-sensitive adhesive is crosslinkable by radiation having a wavelength in the range from 10 to 800 nm, preferably radiation having a wavelength in the range from 200 to 500 nm, more preferably radiation having a wavelength in the range from 350 nm to 485 nm, and even more preferably radiation from an LED light source having an emission maximum in the range from 350 nm to 485 nm.

[0079] 8. The method according to claim 6 or 7, wherein the crosslinkable pressure-sensitive adhesive comprises at least one polymer, at least one epoxy resin, and at least one photoinitiator.

[0080] 9. The crosslinkable pressure-sensitive adhesive is (a) at least one polymer from 20 to 75% by weight, preferably from 30 to 70% by weight; (b) at least one epoxy resin from 20 to 70% by weight, preferably from 30 to 65% by weight; (c) at least one cationic photoinitiator from 0.01 to 5% by weight, preferably from 1 to 4% by weight; The method according to any one of embodiments 6 to 8, comprising

[0081] 10. The method according to claim 8 or 9, wherein the at least one polymer comprises one or more materials selected from the group consisting of polyacrylate, polyurethane, poly(ethylene) vinyl acetate copolymer, poly(ethylene) vinyl acetate copolymer, nitrile rubber, and polyacrylate block copolymer, preferably selected from the group consisting of polyacrylate, poly(ethylene) vinyl acetate copolymer, and polyacrylate block copolymer.

[0082] 11. The method according to any one of claims 8 to 10, wherein the at least one epoxy resin comprises at least one epoxy resin E1 and at least one epoxy resin E2.

[0083] 12. The method according to embodiment 11, wherein the epoxy resin E1 includes an epoxy resin E1 that is solid or highly viscous at 25°C, and the epoxy resin E2 includes an epoxy resin E2 that is liquid at 25°C.

[0084] 13. The method according to embodiment 11 or 12, wherein, as determined according to test method 3, the at least one epoxy resin E1 has a Tg of ≧25°C and the at least one epoxy resin E2 has a Tg of <25°C.

[0085] 14. The method according to any one of embodiments 11 to 13, wherein, as determined according to test method 4, the at least one epoxy resin E1 has a kinematic viscosity of 100 Pa·s or more, preferably 150 Pa·s or more, at 25°C.

[0086] 15. The method according to any one of embodiments 11 to 14, wherein, as determined according to test method 4, the at least one epoxy resin E2 has a kinematic viscosity of 30 Pa·s or less, preferably 20 Pa·s or less, more preferably 10 Pa·s or less, at 25°C.

[0087] 16. The method according to any one of embodiments 11 to 15, wherein, as determined according to test method 5, the at least one epoxy resin E1 has a softening temperature of 45°C or higher.

[0088] 17. The method according to any one of embodiments 11 to 16, wherein E1:E2 is in the range of 10:1 to 1:10, preferably in the range of 4:1 to 1:4.

[0089] 18. The method according to any one of embodiments 8 to 17, wherein the at least one photoinitiator includes one or more materials selected from the group consisting of systems based on sulfonium, iodonium, and metallocene.

[0090] 19. The crosslinkable pressure-sensitive adhesive additionally (d) 3 to 30% by weight, preferably 5 to 20% by weight, more preferably 7 to 15% by weight of at least one elastomer-modified epoxide E3, based on the total weight percentage of the at least one polymer and the at least one epoxy resin, The method according to any one of Embodiments 6 to 18, comprising

[0091] 20. The method according to Embodiment 19, wherein the at least one elastomer-modified epoxide E3 comprises one or more materials selected from the group consisting of carboxy-terminated nitrile rubber, carboxy-terminated butadiene rubber, epoxy-terminated butadiene rubber, epoxy-terminated nitrile rubber, epoxy-functionalized polyurethane, polyester, and polyether.

[0092] 21. The method according to any one of Embodiments 1 to 20, wherein the at least two opposing sidewalls S1 and S2 comprise at least two faces F1 and F2, where sidewall S1 comprises face F1 and sidewall S2 comprises face F2.

[0093] 22. The method according to Embodiment 21, wherein the faces F1 and F2 have the same width.

[0094] 23. The method according to any one of Embodiments 1 to 22, wherein the at least two opposing sidewalls S3 and S4 comprise at least two faces F3 and F4, where sidewall S3 comprises face F3 and sidewall S4 comprises face F4.

[0095] 24. The method according to Embodiment 23, wherein the faces F3 and F4 have the same width.

[0096] 25. The method according to any one of Embodiments 21 to 24, wherein the faces F1 and F2 are wider than the faces F3 and F4.

[0097] 25. The method according to any one of Embodiments 1 to 24, wherein the battery cell is rectangular.

[0098] 26. The method according to any one of Embodiments 1 to 25, wherein the upper surface O includes a battery contact, or the side walls S3 and S4 each include a battery contact.

[0099] 27. The method according to any one of Embodiments 1 to 26, wherein the lower surface U is on the opposite side of the upper surface O.

[0100] 29. The method according to any one of Embodiments 1 to 27, wherein the at least partial crosslinking of the crosslinkable adhesive layer is performed after the step of (ii).

[0101] 31. The method according to any one of Embodiments 1 to 27, wherein the at least partial crosslinking of the crosslinkable adhesive layer is performed after the step of (vi).

[0102] 32. The method according to any one of Embodiments 1 to 31, wherein in (ii), the adhesive film is provided in the form of an adhesive film web wound around a roll.

[0103] 33. (iii) is (iii.1) unwinding of the adhesive film from the roll and, simultaneously therewith, crosslinking of the crosslinkable adhesive layer by radiation having a wavelength in the range from 10 to 800 nm, preferably radiation having a wavelength in the range from 200 to 500 nm, more preferably radiation having a wavelength in the range from 350 nm to 485 nm, and even more preferably radiation from an LED light source having an emission maximum in the range from 350 nm to 485 nm, The method according to Embodiments 1 to 32, preferably Embodiment 32, comprising:

[0104] 34. The method according to any one of Embodiments 1 to 33, wherein the adhesive film has a width b and a length l.

[0105] 35. The method according to Embodiment 34, wherein in step (iii), the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount of the surface Δb1.

[0106] 36. In step (iv), the method according to embodiment 34 or 35, wherein the length l of the adhesive film protrudes from the upper surface O of the battery cell by an amount corresponding to the surface Δl1.

[0107] 37. In step (iv), the method according to any one of embodiments 34 to 36, wherein the width b of the adhesive film protrudes from the at least two opposite side walls S1 and S2 of the battery cell by an amount corresponding to the surface Δb2, where Δb2 < Δb1.

[0108] 38. In step (iv), the method according to any one of embodiments 34 to 37, wherein the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount corresponding to the surface Δb3, where Δb3 < Δb2 < Δb1.

[0109] 39. (iv) is (iv.1) Providing an adhesive device including at least one pressing roller; (iv.2) Guiding the at least one pressing roller onto the side wall S1 and / or side wall S2, including adhesion of the adhesive layer of the adhesive film to the side wall S1 and / or side wall S2 (preferably by pressing the adhesive layer of the adhesive film using the pressing roller). The method according to any one of embodiments 1 to 38, including the above.

[0110] 40. (v) is (v.1) Applying Δb3 onto at least two side walls S3 and S4, including adhesion of the adhesive layer of the adhesive film to the at least two side walls S3 and S4; (v.2) Applying Δb2 onto at least two side walls S3 and S4, including adhesion of the adhesive layer of the adhesive film to the at least two side walls S3 and S4 with the formation of the surface Δl2, where Δl2 < Δl1. The method according to any one of embodiments 34 to 39, including the above.

[0111] 41. (vi) is (vi.1) Applying Δl2 to the upper surface O of the battery cell, including adhering the adhesive layer of the adhesive film to the at least one upper surface O with the formation of the surface Δl3, where Δl3 < Δl2; (vi.2) Applying Δl3 to the upper surface O of the battery cell, including adhering the adhesive layer of the adhesive film to the at least one upper surface O; The method according to any one of Embodiments 34 to 40, including the above.

[0112] 42. A method for coating a battery cell, the steps of which are as follows: (i) Providing a battery cell, including at least two opposite side walls S1 and S2, at least two opposite side walls S3 and S4, at least one lower surface U, and at least one upper surface O; (ii) Providing an adhesive film with width b and length l, including at least one crosslinkable adhesive layer and at least one carrier; (iii) Contacting the adhesive film in (ii) with the at least one lower surface U of the battery cell in (i), including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least one lower surface U of the battery cell, where the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount of the surface Δb1, and Δb1 < b; (iv) Contacting the adhesive film with the at least two side walls S1 and S2, including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least two side walls S1 and S2, where the width b of the adhesive film protrudes from the at least two opposite side walls S1 and S2 of the battery cell by an amount of the surface Δb2, and Δb2 < Δb1; (v) Contacting the adhesive film with the at least two side walls S3 and S4, including adhering the at least one crosslinkable adhesive layer of the adhesive film to the at least two side walls S3 and S4, where the width b of the adhesive film protrudes from the at least two opposite side walls S3 and S4 of the battery cell by an amount of the surface Δb3, and Δb3 < Δb1; (v.1) Applying Δb3 onto the at least two side walls S3 and S4, including adhesion between the adhesive layer of the film and the at least two side walls S3 and S4; (v.2) Applying Δb2 onto the at least two side walls S3 and S4, including adhesion between the adhesive layer of the adhesive film and the at least two side walls S3 and S4 with the formation of surface Δl2, where Δl2 < Δl1; (vi) Contact between the adhesive film and the at least one upper surface O, including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least one upper surface O of the battery cell; (vi.1) Applying Δl2 onto the upper surface O of the battery cell, including adhesion between the adhesive layer of the adhesive film and the at least one upper surface O with the formation of surface Δl3, where Δl3 < Δl2; (vi.2) Applying onto Δl3 on the upper surface O of the battery cell, including adhesion between the adhesive layer of the adhesive film and the at least one upper surface O; including further including at least one step of at least partial crosslinking of the crosslinkable adhesive layer, where at least one step of this crosslinking is performed after the step of (ii) or after the step of (vi), said method.

[0113] 43. A coated battery cell obtainable or obtained by the method according to any one of Embodiments 1 to 42.

Brief Description of the Drawings

[0114]

Figure 1a

Figure 1b

Figure 2

Figure 3

Figure 4

Figure 5

Figure 6

Figure 7

[0115] [Description of the Drawings] Further details and features of the present invention will become apparent from the description of the drawings and examples. Here, each feature can be implemented alone or in combination with others. The present invention is not limited to this example. The example is schematically shown in the drawings. At this time, the same reference numerals in the individual drawings indicate the same, or functionally the same, or elements corresponding to each other with respect to their functions. These drawings are described together.

[0116] Figure 1a shows a battery cell 110 including a bottom surface U111, two opposing side walls S1 and S2112, two opposing side walls S3 and S4113, a top surface O114, and two battery contacts 115 on the top surface 114. Figure 1b shows another variation of the battery cell 110 including a bottom surface U111, two opposing side walls S1 and S2112, two opposing side walls S3 and S4113 (on which there are battery contacts 115 respectively), and a top surface O114. Figures 2 - 7 show various embodiments of the method for coating the battery cell 110 of Figure 1a. In particular, Figure 2 shows an embodiment of the method for coating the battery cell 110. Step (i) 130 indicates the provision of the battery cell 110, where the battery cell includes at least two opposing side walls S1 and S2, at least two opposing side walls S3 and S4, at least one top surface U, and at least one top surface O. Step (ii) 132 indicates the provision of an adhesive film 116 having a width b118 and a length l117. Step (iii) 134 is the contact between the adhesive film 116 and at least one bottom surface U of the battery cell 116, including the adhesion between at least one crosslinkable adhesive layer of the adhesive film 116 and at least one bottom surface U111 of the battery cell, where the width b118 of the adhesive film 116 protrudes by an amount Δb1119 from the bottom surface U111 of the battery cell 110. Step (iv) 136 is the contact between the adhesive film 116 and at least two side walls S1 and S2112, including the adhesion between at least one crosslinkable adhesive layer of the adhesive film 116 and at least two side walls S1 and S2112, where the width b118 of the adhesive film protrudes by an amount Δb2121 from at least two opposing side walls S1 and S2112 of the battery cell 110, and the length l117 protrudes by an amount Δl1120 from the top surface O114 of the battery cell 110.Steps (v) 138 and (vi) 140 are the contact between the adhesive film 116 and at least two side walls S3 and S4 113, including the adhesion between at least one crosslinkable adhesive layer of the adhesive film 116 and at least two side walls S3 and S4 113. Here, the width b 118 of the adhesive film 116 protrudes from the lower surface of the battery cell 110 by the amount of the surface Δb3 122, and Δb3 122 is attached onto at least two side walls S3 and S4 113, and Δb2 121 includes the adhesion between the adhesive layer of the adhesive film 116 while forming the surface Δl2 124 and at least two side walls S3 and S4 113, and is attached onto at least two side walls S3 and S4 113, indicating the contact. Step (vi) 140 is the contact between the adhesive film 116 and at least one upper surface O 114, including the adhesion between at least one crosslinkable adhesive layer of the adhesive film 116 and at least one upper surface O 114 of the battery cell 110. Here, Δl2 124 is adhered onto the upper surface O 114 of the battery cell 110 while forming the surface Δl3 125, and Δl3 125 is adhered onto the upper surface O 114 of the battery cell 110 while including the adhesion between the adhesive layer of the adhesive film 116 and at least one upper surface O 114, including the contact. Further, FIG. 2 shows an embodiment of the coated battery cell 150 and an embodiment of the method for coating the battery cell 110, which further includes at least one step of at least partially crosslinking at least a portion of the crosslinkable adhesive layer using the crosslinking unit 100. FIG. 3 shows an embodiment of the method for coating the battery cell 110, where in step 133, at least partial crosslinking of the crosslinkable adhesive layer after the step of (ii) is performed using the crosslinking unit 100. FIG. 4 shows an embodiment of the method for coating the battery cell 110, where in step 141, at least partial crosslinking of the crosslinkable adhesive layer after the step of (vi) is performed using the crosslinking unit 100. FIG. 5 shows an enlarged portion of step (iv) 136. FIG. 6 shows a preferred embodiment of steps (v) 138 and (vi) 140, where in step 142, first, Δb3 122 is adhered onto at least two side walls S3 and S4 113.Thereafter, in step 143, while forming the surface Δl2124, Δb2121 is adhered onto at least two side walls S3 and S4113. FIG. 7 shows a preferred embodiment of step 140, where the contact between the adhesive film 116 and at least one upper surface O114 includes the adhesion between at least one crosslinkable adhesive layer of the adhesive film 116 and at least one upper surface O114 of the battery cell 110. At this time, in step 145, under the formation of the surface Δl3125, Δl2124 is adhered onto the upper surface O114 of the battery cell 110. Thereafter, Δl3125 is adhered onto the upper surface O114 of the battery cell 110.

[0117] The method of covering the battery cell 110 shown in FIG. 1b proceeds similarly. The method starts with the provision of the battery cell 110, where the battery cell includes at least two opposing side walls S1 and S2, at least two opposing side walls S3 and S4, at least one lower surface U and at least one upper surface O. There are battery contacts on each of the two opposing side walls S3 and S4.

[0118] An adhesive film including at least one crosslinkable adhesive layer and at least one carrier covers the two opposing side walls S1 and S2, the lower surface U and the upper surface O in one piece, where the ends of the adhesive film overlap and are adhered to each other. The adhesive film has a width wider than the opposing side walls S1 and S2, the lower surface U and the upper surface O, and as a result, the adhesive film has overhangs on the two opposing side walls S3 and S4 each having a battery contact. The individual portions forming overhangs on the side walls S1 and S2, on the lower surface U and on the upper surface O are folded in any order and adhered onto each of the side walls S3 and S4.

[0119] The method of covering the battery cell 110 shown in FIGS. 2 to 7 and described in the disclosure related to these drawings, where there are two battery contacts on the upper surface O, is equally applicable to the battery cell 110 where the side walls S3 and S4 each have a battery contact. In this variation of the method according to the invention, the order of sub-steps (v) and (vi) is reversed.

Explanation of Symbols

[0120] 100 Crosslinking Unit 110 Battery Cell 111 Bottom Surface 112 Side Walls S1 and S2 113 Side Walls S3 and S4 114 Top Surface O 115 Battery Contact 116 Adhesive Film 117 Length l 118 Width b 119 Surface Δb1 120 Surface Δl1 121 Surface Δb2 122 Surface Δb3 124 Surface Δl2 125 Surface Δl3 130 Step (i) 132 Step (ii) 133 Crosslinking of the Crosslinkable Adhesive Layer after the Step of (ii) 134 Step (iii) 136 Step (iv) 138 Step (v) 140 Step (vi) 141 Crosslinking of the Crosslinkable Adhesive Layer after the Step of (vi) 142 Step (v.1) 143 Step (v.2) 144 Partially Covered Battery Cell 145 Step (vi.1) 146 Step (vi.2) 150 Covered Battery Cell

Examples

[0121] Test Method Test Method 1: Specific Volume Resistance The specific volume resistance was determined in accordance with DIN EN62631-3-1 (VDE0307-3-1): 2017-01.

[0122] Test method 2: Adhesion The adhesion was determined at 23 °C and 50% relative humidity, with a peeling rate of 300 mm / min and a peeling angle of 180°, following ISO 29862 (Method 3). A steel plate was used as the substrate according to the standard. At this time, the adhesion of the measurement strip was carried out at 4 kg using a pressing roll machine at a temperature of 23 °C. The adhesive film was peeled immediately after application or after a storage period of 24 hours. The measured value (N / cm) was the average of three individual measurements.

[0123] Test method 3: Tg The glass transition temperature of the polymer is determined by dynamic scanning calorimetry (DSC). For this purpose, approximately 5 mg of the untreated polymer sample is weighed into an aluminum crucible (volume 25 μL) and closed with a perforated lid. For the measurement, a DSC 204 F1 from Netzsch is used, and the work is carried out under nitrogen for inerting. This sample is first cooled to -150 °C, heated to +150 °C at a heating rate of 10 K / min, and then cooled back to -150 °C. The subsequent second heating curve is advanced again at 10 K / min to record the change in heat capacity. The glass transition is recognized as a step in the thermogram. The glass transition temperature is evaluated as follows. Tangents are applied to the baseline of the thermogram 1 before and 2 after the step, respectively. In the region of the step, a fitting straight line 3 is placed parallel to the coordinate so that this fitting straight line intersects both tangents, that is, two surfaces 4 and 5 of the same area (each between one tangent, the fitting straight line, and the measurement curve) are generated. The intersection of the fitting straight line positioned in this way and the measurement curve is the glass transition temperature.

[0124] Test method 4: Kinematic viscosity Within the framework of the present invention, the kinematic viscosity is determined at 25 °C at a shear rate of 1 s -1 in accordance with DIN 53019-1, 2008-09 edition.

[0125] Test method 5: Softening temperature Within the framework of the present invention, the softening temperature is carried out based on the corresponding methodology known as the ring and ball method and standardized based on ASTM E28 (1.7.2018).

[0126] To determine the softening temperature of the resin, the Herzog universal automatic device HRB754 is used. First, the resin sample is finely ground. The resulting powder is filled into a brass cylinder with a bottom hole (inner diameter 20 mm at the top of the cylinder, bottom hole diameter 16 mm of the cylinder, cylinder height 6 mm) and melted on a heating table. The filling amount is selected so that after the resin melts, the cylinder is filled without overflowing.

[0127] The resulting test piece is loaded into the sample holder of the HRB754 together with the cylinder. If the softening temperature is between 50 °C and 150 °C, glycerin is used to fill the temperature control bath. In the case of a lower softening temperature, the work can also be done using a water bath. The test ball has a diameter of 9.5 mm and a weight of 3.5 g. Corresponding to the procedure of the HRB754, the ball is placed above the sample body in the temperature control bath and placed on the test body. There is a receiving plate 25 mm below the bottom of the cylinder, and there is a light barrier 2 mm above the receiving plate. During the measurement process, the temperature is raised at 5 °C / min. Within the temperature range of the softening temperature, the ball begins to move through the bottom hole of the cylinder and finally stops on the receiving plate. At this position, the ball is detected by the light barrier, and the temperature of the temperature control bath is recorded at this time. Measure in duplicate. The softening temperature is the average value from both individual measurements.

[0128] The raw materials used in the examples and comparative examples are summarized in Table 1.

[0129]

Table 1

[0130] Examples K1 - K3 and Comparative Examples V1 - V3 The adhesive layers of Examples K1 - K3 and Comparative Examples V2 - V3 were produced according to the weight ratios (wt%) in Table 2. Comparative Example V1 is a commercially available electrically insulating adhesive tape composed of a 50 μm polyethylene terephthalate carrier and a 35 μm acrylate adhesive layer.

[0131]

Table 2

[0132] The adhesive dissolved in butanone was spread on a 50 μm polyethylene terephthalate carrier with a layer thickness of 35 μm, the solvent was removed in a drying oven at 105 °C, and then it was covered with a silicone-treated PET liner.

[0133] Adhesive strength The adhesive strength of the obtained adhesive layer was measured at a layer thickness of 100 μm and expressed in MPa. Curing conditions: Examples K1 and K2 and Comparative Examples V2 and V3 were irradiated with 365 nm UV-LED at 4 J / cm 2 and adhered within less than 1 minute after activation. The measurement was carried out 7 days after post-curing at 23 °C. Comparative Example V1 is a non-reactive pressure-sensitive adhesive, so activation is not required. Example K3 is a heat-curable reactive pressure-sensitive adhesive, which cures at 145 °C for 25 minutes after application.

[0134] Determination of adhesive strength using tensile shear test As a characteristic value for the achieved adhesive quality, the adhesive strength of the bonded bodies produced according to the method of the present invention was determined for various adhesive tapes. For this purpose, the adhesive strength was quantitatively determined at 23 °C and 50% relative humidity in a dynamic tensile shear test according to DIN EN 1465:2009-07 at a test speed of 10 mm / min (the results are shown in N / mm 2 = MPa). As the test bar, a steel bar washed with acetone before adhesion was used. The average value is described from three measurements.

[0135] Method example For bubble-free adhesion of the battery cell wall with an adhesive film, for example, a roll is suitable, which presses the adhesive tape onto the battery cell wall starting from one side while rotating.

[0136] Comparative Example M1 A rectangular PET adhesive film piece with a crosslinkable adhesive layer was cut out and the liner was removed. Then, this adhesive film was irradiated with a dose of 4 J / cm 2 using Hoenle UV-LED 365 nm (UV-LED, 365 nm, 1000 mJ / cm 2 s for 4 seconds). K2 was used as the adhesive layer. The coating of the battery cell was performed in the following order. 1) Adhesion of the adhesive layer of the adhesive film to the lower surface U of the battery cell; 2) Adhesion of the adhesive layer of the adhesive film to the two wide side walls S1 and S2; 3) Adhesion of the overhang portion Δb3 of the lower surface U to the narrow side walls S3 and S4; 4) Adhesion of the side overhang portion Δb2 to the narrow side walls S3 and S4; 5) Adhesion of the overhang portions Δl2 of the narrow side walls S3 and S4 to the upper surface O of the battery cell; 6) Adhesion of the overhang portions Δl3 of the wide side walls S1 and S2 to the upper surface O of the battery cell.

[0137] Method Example M2 Method Example M2 was performed in the same manner as Method Example M1, where the irradiation was performed including the liner. This was irradiated with a dose of 4 J / cm 2 (UV-LED 365 nm, 100 mJ / cm2 s for 4 seconds), then the liner was removed, and the battery cell was coated as described in Method Example M1.

[0138] Method Example M3 Method Example M3 was performed as Method Example M1, except that the adhesive film was irradiated only after the battery cell was completely coated. In this case, in order for the adhesive film to reach the regions that are multilayered due to the folding process and the overlaying, a dose exceeding 5 J / cm 2 was used (UV-LED 365 nm, 1000 mJ / cm 2 s was used for 10 seconds on each side).

[0139] Method Example M4 A rectangular PET adhesive film piece with a crosslinkable adhesive layer was cut out and the liner was removed. K3 was used as the adhesive layer. The coating of the battery cell was carried out in the following order. 1) Adhesion of the adhesive layer of the adhesive film to the lower surface U of the battery cell; 2) Adhesion of the adhesive layer of the adhesive film to the two wide side walls S1 and S2; 3) Adhesion of the overhang portion Δb3 of the lower surface U to the narrow side walls S3 and S4; 4) Adhesion of the side overhang portion Δb2 to the narrow side walls S3 and S4; 5) Adhesion of the overhang portion Δl2 of the narrow side walls S3 and S4 to the upper surface O of the battery cell; 6) Adhesion of the overhang portion Δl3 of the wide side walls S1 and S2 to the upper surface O of the battery cell.

[0140] Next, after the coating of the battery cell, the adhesive film was exposed to thermal energy (at 140 °C for 20 minutes).

[0141] Method Example M5 Method Example M5 was carried out in the same manner as Method Example M1, where K1 was used as the adhesive layer.

[0142] Comparative Method Example Comparative Method Example VM1 A rectangular PET adhesive film piece with a crosslinkable adhesive layer was cut out and the liner was removed. Then, this adhesive film was irradiated using a Hoenle UV-LED 365 nm with a dose of 4 J / cm 2 . K2 was used as the adhesive layer. The coating of the battery cell was carried out in the following order. 1) Adhesion of the adhesive layer of the adhesive film to the lower surface U of the battery cell; 2) Adhesion of the adhesive layer of the adhesive film to the two wide side walls S1 and S2; 3) Adhesion of the side overhang portion Δb2 to the narrow side walls S3 and S4; 4) Adhesion of the overhang portion Δb3 of the lower surface U to the narrow side walls S3 and S4; 5) Adhesion of the overhang portion Δl2 of the narrow side walls to the upper surface O of the battery cell; 6) Adhesion of the overhanging portion Δl3 of the wide side wall to the upper surface O of the battery cell.

[0143] In VM1, compared with M1 to M5, the order of steps 3) and 4) is reversed.

[0144] Comparison method example VM2 A rectangular PET adhesive film piece with a crosslinkable adhesive layer was cut out and the liner was removed. Then, this adhesive film was irradiated with a dose of 4 J / cm 2 using Hoenle UV-LED 365 nm. K2 was used as the adhesive layer. The coating of the battery cell was performed in the following order. 1) Adhesion of the adhesive layer of the adhesive film to the lower surface U of the battery cell; 2) Adhesion of the adhesive layer of the adhesive film to the two wide side walls S1 and S2; 3) Adhesion of the side overhanging portion Δb2 to the narrow side walls S3 and S4; 4) Adhesion of the overhanging portion Δb3 of the lower surface U to the narrow side walls S3 and S4; 5) Adhesion of the overhanging portion Δl3 of the wide side wall to the upper surface O of the battery cell; 6) Adhesion of the overhanging portion Δl2 of the narrow side wall to the upper surface O of the battery cell.

[0145] In VM2, compared with M1 to M5, the order of steps 3) and 4), and steps 5) and 6) is reversed.

[0146] The results of the coating of the battery cells of method examples M1 to M5 and comparison method examples VM1 to VM2 are summarized in Table 3.

[0147]

Table 3

[0148] Penetration test For quality assessment, the battery cells wrapped with insulating adhesive tape were stored in a climate chamber at 85 °C and 85% relative humidity (r.F.) for 1000 hours. This test was evaluated as passing if, after said time, no lifting of the adhesive edge occurred for any of the adhesions. Failure means that the insulating adhesive tape has peeled off and separated from the cell at at least one location (in most cases, in the folding area).

[0149] Using bonding method M1, an adhesive film using adhesive layers K1 and V1 was also bonded and evaluated. When using K1, a sufficient adhesive strength of more than 4 MPa was achieved and the penetration test was passed. Comparative example V1 is the commercial pressure-sensitive adhesive tesa® 58353 which does not have sufficient adhesive strength to function as an adhesive base for other liquid adhesives. Examples V2 and V3 do indeed feature high adhesive strength after curing, but are too soft due to lack of epoxide solid resin or due to too low polymer content, and as a result, the adhesive layer has too low cohesion, which appears as cohesive failure in the uncured state in the adhesion test. Such flexible adhesives are not very suitable for the claimed method because, on the one hand, due to their low cohesion, they flow out at the sides from the wound adhesive tape roll and as a result tend to adhere the rolls, and on the other hand, during adhesion at the edge perimeter, due to the restoring force of the carrier film, there is a risk of film lifting ("edge lifting") or peeling. In comparative method VM1, the folding joints at the narrow side walls S3 and S4 bonded in step 4) peeled off. In comparative method VM2, the edges of the narrow side walls on the upper surface bonded in step 6) peeled off. This application relates to the invention described in the claims, but the disclosure of this application also includes the following: 1. A method for coating a battery cell, the steps of which are: (i) Providing a battery cell, the battery cell including at least two opposing side walls S 1 and S 2 , at least two opposing side walls S 3 and S 4 , at least one bottom surface U, and at least one top surface O; (ii) Providing an adhesive film, the adhesive film including at least one crosslinkable adhesive layer and at least one carrier; (iii) Contacting the adhesive film of (ii) with at least one bottom surface U of the battery cell of (i), the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least one bottom surface U of the battery cell; (iv) Contacting the adhesive film with the at least two side walls S 1 and S 2 , the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S 1and S 2 ; (v) Contacting the adhesive film with the at least two side walls S 3 and S 4 , the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S 3 and S 4 ; (vi) Contacting the adhesive film with the at least one top surface O, the contact including adhesion between the at least one crosslinkable adhesive layer of the adhesive film and the at least one top surface O of the battery cell; including at least one step of at least partial crosslinking of the crosslinkable adhesive layer, and wherein at least one step of this crosslinking can be performed after the steps from (ii) to (vi), the method. 2. The method according to 1. above, wherein the carrier includes an insulating carrier, preferably an electrical insulating carrier, more preferably an electrical insulating carrier having a specific volume resistance of >10 15 Ωcm, preferably >10 16 Ωcm, more preferably >10 17 Ωcm as determined in accordance with DIN EN62631-3-1 (VDE0307-3-1): 2017-01. 3. The method according to 1. or 2. above, wherein the carrier comprises one or more materials selected from the group consisting of polyimide, polybenzimidazole, polyamideimide, polyetherimide, polyacetal, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, polyamide 6, ultra-high molecular weight polyethylene, polypropylene, vinyl chloride resin, polystyrene, polyethylene terephthalate, acrylonitrile butadiene styrene, polycarbonate, polyvinyl chloride, ethylene vinyl acetate, and polyester, preferably selected from the group consisting of polypropylene, polyethylene terephthalate, polycarbonate, and polyvinyl chloride. 4. The method according to any one of 1. to 3. above, wherein the crosslinkable adhesive layer has a thickness in the range of 10 to 150 μm, preferably in the range of 10 to 100 μm, more preferably in the range of 20 to 60 μm. 5. The method according to any one of 1. to 4. above, wherein the crosslinkable adhesive layer comprises a crosslinkable pressure-sensitive adhesive, and the crosslinkable pressure-sensitive adhesive comprises at least one polymer, at least one epoxy resin, and at least one photoinitiator. 6. The crosslinkable pressure-sensitive adhesive is (a) at least one polymer from 25 to 75% by weight, preferably from 30 to 70% by weight; (b) at least one epoxy resin from 20 to 70% by weight, preferably from 30 to 65% by weight; (c) at least one cationic photoinitiator from 0.01 to 5% by weight, preferably from 1 to 4% by weight; The method according to 5. above, comprising. 7. The at least one epoxy resin comprises at least one epoxy resin E 1 and at least one epoxy resin E 2 and determined according to test method 3, the at least one epoxy resin E 1 has a Tg of ≧25° C., and the at least one epoxy resin E 2 has a Tg of <25° C., the method according to 5. or 6. above. 8. The crosslinkable pressure-sensitive adhesive additionally comprises (d) at least one elastomer-modified epoxide E from 3 to 30% by weight, preferably from 5 to 20% by weight, more preferably from 7 to 15% by weight, based on the total weight percentage of the at least one polymer and the at least one epoxy resin. 3 、 and the at least one elastomer-modified epoxide E 3 The method according to any one of 5. to 7. above, comprising one or more materials selected from the group consisting of carboxy-terminated nitrile rubber, carboxy-terminated butadiene rubber, epoxy-terminated butadiene rubber, epoxy-terminated nitrile rubber, epoxy-functionalized polyurethane, polyester and polyether. 9. The method according to any one of 1. to 8. above, wherein the at least partial cross-linking of the cross-linkable adhesive layer is carried out after step (ii), or the at least partial cross-linking of the cross-linkable adhesive layer is carried out after step (vi). 10. The adhesive film has a width b and a length l, wherein in step (iii), the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount Δb 1 and in step (iv), the width b of the adhesive film protrudes from the at least two opposite side walls S 1 and S 2 of the battery cell by an amount Δb 2 and protrudes from the lower surface U of the battery cell by an amount Δb 3 , where Δb 3 <Δb 2 <Δb 1 and Δb 2 <Δb 1 and (v) comprises (v.1) attaching Δb 3 to the at least two side walls S 4 and S 3 including adhesion of the adhesive layer of the adhesive film to the at least two side walls S 4 and S 3 ; (v.2) attaching Δb 2 to the at least two side walls S 3 and S 4 including adhesion of the adhesive layer of the adhesive film to the at least two side walls S 3 and S 4 accompanied by the formation of a surface Δl 2 ; The method according to any one of 1. to 9. above, comprising. 11. (vi) comprises (vi.1) attaching Δl 3 to the upper surface O of the battery cell including adhesion of the adhesive layer of the adhesive film to the at least one upper surface O accompanied by the formation of a surface Δl 2 , where Δl 3 <Δl 2 ; (vi.2) attaching Δl 3 to the upper surface O of the battery cell including adhesion of the adhesive layer of the adhesive film to the at least one upper surface O; The method according to 10. above, comprising. 12. A coated battery cell obtainable or obtained by the method according to any one of 1. to 11. above.

Claims

【Claim 1】 A method for coating a battery cell, the steps of which are (i) providing a battery cell, the battery cell including at least two opposing side walls S １ and S ２ , at least two opposing side walls S ３ and S ４ , at least one bottom surface U, and at least one top surface O; (ii) providing an adhesive film, the adhesive film including at least one crosslinkable adhesive layer and at least one carrier; (iii) contacting the adhesive film of (ii) with at least one bottom surface U of the battery cell of (i), the contact including bonding of the at least one crosslinkable adhesive layer of the adhesive film and the at least one bottom surface U of the battery cell; (iv) contacting the adhesive film with the at least two side walls S １ and S ２ , the contact including bonding of the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S １ and S ２ ; (v) contacting the adhesive film with the at least two side walls S ３ and S ４ , the contact including bonding of the at least one crosslinkable adhesive layer of the adhesive film and the at least two side walls S ３ and S ４ ; (vi) contacting the adhesive film with the at least one top surface O, the contact including bonding of the at least one crosslinkable adhesive layer of the adhesive film and the at least one top surface O of the battery cell; including at least one step of at least partial crosslinking of the crosslinkable adhesive layer, wherein at least one step of this crosslinking can be performed after the steps from (ii) to (vi), and ・The crosslinkable adhesive layer contains a crosslinkable pressure-sensitive adhesive, and the crosslinkable pressure-sensitive adhesive contains at least one polymer, at least one epoxy resin, and at least one photoinitiator, and ・The crosslinkable pressure-sensitive adhesive (a) at least one polymer from 25 to 75% by weight; (b) at least one epoxy resin from 20 to 70% by weight; (c) at least one cationic photoinitiator from 0.01 to 5% by weight; and ・The at least one epoxy resin contains at least one epoxy resin E1 and at least one epoxy resin E2, and as determined by dynamic scanning calorimetry (DSC), the at least one epoxy resin E1 has a Tg of ≧25°C, and the at least one epoxy resin E2 has a Tg of <25°C, ・The adhesive film has a width b and a length l, where in step (iii), the width b of the adhesive film protrudes from the lower surface U of the battery cell by an amount Δb1, and in step (iv), the width b of the adhesive film protrudes from the at least two opposite side walls S1 and S2 of the battery cell by an amount Δb2, and also protrudes from the lower surface U of the battery cell by an amount Δb3, where Δb3 < Δb2 < Δb1, and Δb2 < Δb1, and (v) is (v.1) Affixing of Δb3 onto the at least two side walls S3 and S4, including adhesion of the adhesive layer of the adhesive film to the at least two side walls S3 and S4; (v.2) Affixing of Δb2 onto the at least two side walls S3 and S4, including adhesion of the adhesive layer of the adhesive film to the at least two side walls S3 and S4, with the formation of a surface Δl2 after (v.1); and ・(vi) is (vi.1) Affixing Δl2 to the upper surface O of the battery cell, including adhesion of the adhesive layer of the adhesive film to the at least one upper surface O accompanied by the formation of the surface Δl3, where Δl3 < Δl2; (vi.2) Affixing Δl3 to the upper surface O of the battery cell, including adhesion of the adhesive layer of the adhesive film to the at least one upper surface O after (vi.1); including the method. **Claim 2** The method according to claim 1, wherein the carrier includes an insulating carrier. **Claim 3** The method according to claim 1 or 2, wherein the carrier includes one or more materials selected from the group consisting of polyimide, polybenzimidazole, polyamideimide, polyetherimide, polyacetal, polyphenylene sulfide, polyetheretherketone, polytetrafluoroethylene, polyamide 6, ultra-high molecular weight polyethylene, polypropylene, vinyl chloride resin, polystyrene, polyethylene terephthalate, acrylonitrile butadiene styrene, polycarbonate, polyvinyl chloride, ethylene vinyl acetate, and polyester. **Claim 4** The method according to claim 1 or 2, wherein the crosslinkable adhesive layer has a thickness in the range of 10 to 150 μm. **Claim 5** The crosslinkable pressure-sensitive adhesive additionally (d) at least one elastomer-modified epoxide E in an amount of 3 to 30% by weight based on the total weight % of the at least one polymer and the at least one epoxy resin ３ , and the at least one elastomer-modified epoxide E ３ includes one or more materials selected from the group consisting of carboxy-terminated nitrile rubber, carboxy-terminated butadiene rubber, epoxy-terminated butadiene rubber, epoxy-terminated nitrile rubber, epoxy-functionalized polyurethane, polyester, and polyether. The method according to claim 1 or 2. Claim 6 The method according to claim 1 or 2, wherein the at least partial crosslinking of the crosslinkable adhesive layer is carried out after the step of (ii), or the at least partial crosslinking of the crosslinkable adhesive layer is carried out after the step of (vi). Claim 7 A coated battery cell obtainable or obtained by the method according to claim 1 or 2.

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