DE102022104035A1 - Accumulator with at least one accumulator cell and method for producing an accumulator - Google Patents

Abstract

The invention relates to an accumulator (10) with (a) at least one accumulator cell (12), wherein (b) the accumulator cell (12) is surrounded in the circumferential direction by a flat or three-dimensional textile structure (24) containing a substance containing water of crystallization, in particular ettringite is at least substantially completely surrounded.

Description

The invention relates to an accumulator with at least one accumulator cell. According to a second aspect, the invention relates to a method for producing an accumulator.

Such accumulators are, for example, from DE 10 2017 127 337 A1 known and are used to store electrical energy. As a rule, such accumulators consist of a large number of accumulator cells. Each accumulator cell consists of one or more than one galvanic element. If there are two or more accumulator cells, they are usually connected in series, so that the cell voltages add up. Such accumulators are used, for example, in stationary energy stores, ie in energy stores that are designed not to be moved during operation. However, such accumulators are preferably used in vehicles, in particular in land vehicles and increasingly in airplanes.

Accumulator cells can run away, in particular due to aging and/or unfavorable charging or discharging loads. A runaway is understood to mean that an electrochemical reaction occurs that releases enough heat that the electrochemical reaction amplifies itself. In this way, so much heat is generated in such a short time that the accumulator is completely destroyed.

To prevent this from the U.S. 10,008,704 B2 known to cover the end faces of the accumulator cells with a cover that forms a one-way valve.

If an accumulator cell explodes, the gas escapes through the cover without causing such severe thermal damage to the other cells that they too fail.

The U.S. 7,749,650 B1 describes a battery that is surrounded by at least a two-layer film. The first film layer is designed to be insulating, the second film layer has a perforation. A similar battery is from the U.S. 8,361,649 B2 known.

The U.S. 8,541,126 B2 describes a battery pack in which groups of accumulator cells are separated from one another by a barrier. In this way, although the accumulator cells in a group can fail if one accumulator cell in the group fails, the damage is prevented from spreading to another group.

From the U.S. 9,093,726 B2 a battery pack is known which has a channel filled with liquid. The channel has predetermined breaking points that fail at elevated temperatures. If thermal runaway occurs, i.e. a strongly exothermic reaction of a battery element, the predetermined breaking point breaks, the liquid escapes and cools the battery pack at the translated point.

In the U.S. 2010/0151308 A1 describes a battery pack in which air gaps are arranged between two layers of round cells. The thermal capacity of the round cells on the one hand and the dimensions of the air gap are selected in such a way that the runaway from a damaged battery cell is prevented from spreading to an adjacent layer.

In the accumulator from the U.S. 8,592,076 B2 is known, individual batteries are separated from one another by a separator plate containing intumescent material. In the event of an accident, the intumescent material foams up and thus prevents the damage from spreading.

It is desirable for accumulators, in particular for use in a vehicle, to be well protected against thermal runaway on the one hand and to be as light as possible on the other. However, both demands are in conflict.

The invention is based on the object of proposing an accumulator which is well protected against thermal runaway and which can nevertheless be manufactured with a low weight in comparison to other solutions.

The invention solves the problem by means of a generic accumulator in which the accumulator cell is at least essentially completely surrounded in the circumferential direction by a flat or three-dimensional textile structure which contains a substance containing water of crystallization, in particular ettringite. Calcium aluminate sulfate is also considered an ettringite powder.

According to a second aspect, the invention solves the problem by a method for producing an accumulator with the step of wrapping an accumulator cell, in particular a housing of the accumulator cell, with a flat or three-dimensional textile structure that contains a substance containing water of crystallization, in particular a substance containing ettringite . Alternatively or additionally, the method comprises the steps (a) wrapping a sleeve with a flat or three-dimensional textile structure containing a substance containing water of crystallization, in particular ettringite and (b) inserting the storage battery cell into the sleeve.

The advantage of the invention is that the use of the flat or three-dimensional textile structure means that on the one hand only a small additional weight is introduced into the accumulator and on the other hand the spread of an accident can be contained.

It is also advantageous that such an accumulator can be manufactured comparatively easily. So it is usually easy to surround a storage battery cell, which is preferably a round cell, with the flat or three-dimensional textile structure. For example, the accumulator cell is wrapped with a flat textile structure. The provision of the accumulator cell with the fire protection element from the flat or three-dimensional textile structure that contains the substance containing water of crystallization is thus part of the—generally automated—manufacturing of the accumulator cells. The subsequent arrangement of the battery cells to the battery remains unchanged, so that an existing production process hardly needs to be changed.

In the context of the present description, the feature that the accumulator has at least one accumulator cell means in particular that the accumulator has 2, 3, 4, 5 or a larger number of accumulator cells. Each accumulator cell preferably has a nominal cell voltage of at least 2 volts, in particular at least 4 volts. Each accumulator cell preferably has a nominal cell voltage of at most 6 volts.

A capacity of the accumulator cells is preferably at least 3 ampere hours, in particular at least 4 ampere hours, preferably preferably 5 ampere hours. The capacity of the accumulator cells is preferably at most 15 ampere hours, in particular at most 10 ampere hours.

The accumulator preferably includes so many accumulator cells that they deliver a voltage of at least 40 V when they are connected in series.

An accumulator cell is understood to mean, in particular, a self-contained unit that has exactly one galvanic element. In particular, the accumulator cell has two electrical contacts, namely one for the positive pole and one for the negative pole. The accumulator cell preferably has a housing. The housing preferably does not enclose charging circuitry. In other words, the accumulator cell only represents the galvanic element.

The accumulator cells are preferably secondary cells, that is to say rechargeable galvanic elements. The accumulator cells are, for example, lithium cells or sodium cells. In particular, the accumulator cells can contain a liquid electrolyte.

The feature that the accumulator cell is surrounded by the textile structure means in particular that each accumulator cell is surrounded by its own textile structure. Although it is possible that not all battery cells are surrounded by a textile structure, it is favorable if there are no two battery cells that are surrounded by the same textile structure lying side by side. As a rule, it is the same textile structure, but not the same. However, it is possible and provided according to a preferred embodiment that two, in particular prismatic battery cells, which are arranged one behind the other in the longitudinal direction, are surrounded by the same, in particular continuous, textile structure. In other words, the same textile material is used for at least the majority of the battery cells.

The feature that the textile structure at least essentially completely surrounds the battery cell in the circumferential direction means in particular that, viewed from the geometric center of gravity of the cross section of the battery cell, the angular interval along which the structure extends is at least 0.9 * 2π, in particular 0.95 ∗ 2π. It is particularly favorable if the textile structure completely surrounds the accumulator cell in the circumferential direction. In this case the angular interval is 2π. The cross section of the battery cell runs perpendicular to a longitudinal direction of the battery cell. If the accumulator cell is prismatic, as provided according to a preferred embodiment, the longitudinal direction runs along the longitudinal axis of the prism.

The substance containing water of crystallization preferably has an activation temperature which is below 150.degree. C., in particular below 120.degree. The activation temperature is understood to mean, in particular, the extrapolated initial temperature T _ei,r according to EN ISO 11357-1/-5. Above the activation temperature, the substance containing water of crystallization releases water of crystallization. Water has a high heat of vaporization, so that a lot of heat is absorbed during evaporation.

It is favorable if the substance containing water of crystallization has a binder which connects the substances containing water of crystallization of the substance containing water of crystallization to one another. The binder is preferably a polymer. It is favorable if the binder contains a polyacrylate, in particular the binder consists at least predominantly of polyacrylate in relation to percentages by mass. For example, the binder contains at least predominantly polyvinyl acetate. It is favorable if the binder contains ethyl vinyl acetate. For example, the binder contains at least 15% by weight of vinyl acetate.

The heat absorption capacity means the ability of the substance containing water of crystallization to absorb heat above an activation temperature, which can also be called the initial temperature T _ei,r . In particular, the heat absorption capacity is the heat change Δq according to EN ISO 11357-1 (3.5). The heat absorption capacity Δq, in particular from the initial temperature T _ei,r to 200°C, is at least 500 kilojoules per kilogram, in particular at least 750 kJ/kg. An upper limit for the heat absorption capacity Δq is preferably 1000 kJ/kg. The heat absorption is greater than the heat absorbed due to the heat capacity of the heat absorbing substance when heated.

According to a preferred embodiment, the heat absorbing substance has an extrapolated initial temperature T _ei,r which is below 100°C, in particular below 80°C. The reaction onset temperature T _i,r according to EN ISO 11357-1/-5 is particularly preferably below 80.degree. This causes the substance containing water of crystallization to develop its cooling effect in good time.

The water of crystallization substance preferably has a heat capacity of at least 500 joules per gram.

An area-specific mass of the textile structure of substance containing water of crystallization is preferably at least 300 grams per square meter, preferably at least 450 grams per square meter, in particular at least 600 grams per square meter. The area is the respective area of the material that is used to produce the textile structure.

The proportion of substance containing water of crystallization in the total mass per unit area of the textile structure is preferably at least 60 percent by weight, preferably at least 80 percent by weight, particularly preferably at least 95 percent by weight.

The textile structure preferably has a total heat absorption capacity which corresponds to at least 0.2 times, in particular at least 0.4 times, the energy content of the accumulator cell. The energy content of the accumulator cell is the maximum amount of electrical energy that can be stored in the accumulator cell without exceeding the nominal voltage.

The textile structure preferably has at least or exactly one substance, in particular at least or exactly two substances, in particular at least or exactly three substances from the following list: MgCO ₃ .3H ₂ O (nesquehonite), 3CaO.Al ₂ O ₃ .3CaSO ₄ .32H ₂ O (ettringite), AlNH ₄ (SO ₄ ) ₂ .12H ₂ O, KAI(SO ₄ ) ₂ .12H ₂ O, Al ₂ (SO ₄ ) ₃ .12H ₂ O (alunogen), Al ₂ (SO ₄ ) ₃ .18H ₂ O; MgSO ₄ .7H ₂ O (Epsom salts) + derivatives, _MgCl2 · _6H2 O; C _U SO ₄ .5H ₂ O (+ derivatives), FeSO ₄ .7H ₂ O (+ derivatives), CaSO ₄ .2H ₂ O, _Na3 ( _HCO3 ) _{CO3.2H2O ; H3 BO3} , Na ₂ SiO ₃ .9H ₂ O (+ derivatives) and Mg(NO ₃ ) ₂ .6H ₂ O and other hydration levels of these substances.

Ettringite already releases water of crystallization at 80°C, which evaporates and vaporizes when it exceeds 100°C. The heat of vaporization of water is extremely high, so the crystal water released from ettringite effectively cools the continuous battery.

The textile structure is in particular not a thread or a rope. Of course, the textile structure can be made up of a thread or a rope. The decisive factor is that the textile structure is formed by a large number of threads and/or by at least one thread or a rope, which forms a flat or three-dimensional structure. This can be done, for example, by meshing or weaving.

The textile structure is preferably a woven, knitted or crocheted fabric, mesh, stitched fabric, non-woven fabric or felt. It is favorable if the textile structure forms a textile web under a textile product refers to a textile structure whose length is at least ten times greater than its width.

The textile structure is preferably constructed from fire protection textile. A fire protection textile is understood to mean, in particular, a fabric, non-crimp fabric or knitted fabric that is non-combustible and withstands thermal stress for a sufficiently long period of time to prevent flames and/or smoke from passing through, in particular for at least 30 minutes in accordance with EN 1634-3 and/or DIN EN 12101 -1 to resist. The advantage of using fire protection textiles is the low production costs. It is thus possible to produce the fire protection element from one, two, three or more flat pieces of fire protection textile by connecting, in particular sewing.

The textile structure can have a combustible substance, for example a polymer such as polyester in particular. In particular, the textile structure can have a proportion by weight of at least 10 percent by weight of combustible substance. The proportion by weight of combustible substance is preferably at most 70 percent by weight, in particular at most 50 percent by weight, particularly preferably at most 30 percent by weight. Intuitively, the use of combustible substances in a device intended to prevent a thermal failure from spreading from a failing battery element to adjacent battery elements makes no sense. However, it was surprisingly found that combustible material can be used. This is advantageous because combustible material is usually easier to process and/or has a lower density than non-combustible material. Combustible material is understood to mean a material that reacts exothermically in air above an ignition temperature.

The flat textile structure preferably has an area-specific mass of 15-30 g/square meter. Alternatively or additionally, the textile structure has a thickness of 0.7-2.5 mm, in particular 1.0-1.8 mm.

According to a preferred embodiment, the textile structure forms at least two winding layers. This means in particular that at every point on the circumference of the accumulator cell there are at least two layers of the textile structure one behind the other in the radial direction.

It is favorable if the textile structure is designed as a hose or stocking. In this case it is advantageous if two, three or more accumulator cells are arranged in the longitudinal direction, that is to say along their longitudinal extension, in particular coaxially, in the same tube. A hose is understood to mean, in particular, a textile structure which is flexible and/or not dimensionally stable with respect to a force acting in the radial direction. In other words, a hose deviates from a radially acting force in the radial direction. Alternatively or additionally, a tube is flexible. In particular, this means that it can be elastically repeatedly bent without breaking. A stocking is understood to mean a hose that is closed on one side.

Alternatively, it is favorable if the textile structure is designed as a sleeve or is part of a sleeve. The sleeve surrounds an accumulator cell, in particular precisely one accumulator cell or two, three or more, in particular prismatic, accumulator cells which are arranged one behind the other in the longitudinal direction.

The sleeve preferably has a sleeve thickness of 0.7-2.5 mm, in particular 1.0-1.8 mm. The sleeve thickness is the difference between an outer cylinder diameter of an imaginary compensating cylinder through the outer surface of the sleeve on the one hand and an inner cylinder diameter of an imaginary compensating cylinder through the inner surface of the sleeve on the other hand.

Such a thickness has the advantage that, on the one hand, the spread of an accident can be stopped and, on the other hand, there is only a comparatively small additional weight.

According to a preferred embodiment, the accumulator cell is arranged with play in the sleeve. In particular, there is a gap, in particular an annular gap, between the battery cell and the sleeve. The gap, in particular the annular gap, has a clear width of preferably at least 0.05, in particular 0.1 mm. If the accumulator cell fails, it can burst on its lateral surface. This creates a lower peak pressure, making it less likely to damage adjacent cells.

In particular when the textile structure is applied directly to the accumulator cell, it is favorable if the textile structure has an adhesive at least in sections, in particular if it is self-adhesive. Acrylate, for example, is used as an adhesive. It is then possible and provided according to a preferred embodiment of the method according to the invention to bring the textile structure into contact with the battery cell in such a way that the adhesive sticks to the battery cell. This enables a particularly simple production. Alternatively, the textile structure can be glued onto a core body. The battery cell is then preferably in the Introduced sleeve body, in particular inserted.

The accumulator preferably has at least one second accumulator cell, wherein the at least one second accumulator cell is at least essentially surrounded by a second planar or three-dimensional textile structure containing water of crystallization, in particular containing ettringite.

The structure and/or the sleeve preferably encloses the accumulator cell by at least 80%, in particular at least 90%, preferably completely, with respect to the longitudinal direction of the accumulator cell.

The textile structure is preferably made up of at least one yarn which contains ettringite. In this case, the hydrous substance, particularly the ettringite, is located inside the yarn and is surrounded by a sheath material and/or the hydrous substance is present on a surface of the yarn. The yarn is understood to mean, in particular, a yarn in accordance with DIN 60900-1:1988-07, in particular a linear, thin textile structure made from one or more fibers.

Alternatively or additionally, the textile structure has at least two layers of textile material, between which the substance containing water of crystallization is arranged.

It is particularly favorable if the textile structure has a coating containing water of crystallization, in particular containing ettringite.

In order to dissipate further heat in the event of a battery cell failure, it is favorable if the textile structure contains and/or is coated with a phase change material.

The accumulator preferably has a large number of accumulator cells, each of which has a housing and is at least essentially completely surrounded in the circumferential direction by a planar or three-dimensional textile structure containing water of crystallization, in particular containing ettringite, with the accumulator cells being arranged in a regular pattern.

It is favorable if the textile structure has a casing made of metal, in particular aluminum foil. If the accumulator cell and thus the textile structure heats up locally, the metal shell causes the temperature gradient to decrease. This in turn reduces the likelihood of an adjacent battery cell overheating.

It is favorable if at least a majority of the accumulator cells has a front side and a bottom side that is opposite the front side and is not completely surrounded by the textile structure. If the accumulator cell breaks down, the resulting hot gas can escape through the front or the bottom.

It is particularly favorable if a cover containing water of crystallization, in particular containing ettringite, is arranged on the front side and/or the bottom side. When the accumulator cell goes through, the cover is pushed off so that hot gases can escape from the cell. The adjacent accumulator cells are protected from the resulting heat by the cover.

• 1 in der 1a einen erfindungsgemäßen Akkumulator in einer dreidimensionalen Ansicht, in der 1b eine perspektivische schematische Ansicht einer Akkumulatorzelle, die von einer Hülse umgeben ist und in der 1c die Hülse aus 1b,
• 2 in der 2a einen schematischen Querschnitt durch das textile Gebilde, in der 2b einen Querschnitt quer zur Längsachse durch eine Akkumulatorzelle, die mit dem textilen Gebilde umgeben ist, das auf einer Hülse angeordnet ist, in der 2c einen Querschnitt quer zur Längsachse durch und eine Akkumulatorzelle, an deren Gehäuse das textile Gebilde angeklebt ist und in der 2d einen Querschnitt durch eine textiles Gebilde gemäß einer zweiten Ausführungsform, dass zwei Lagen hat.
• 3 zeigt einen Querschnitt durch eine Akkumulatorzelle, die von einem textilen Gebilde umgeben ist und einen Deckel aufweist.

The invention is explained in more detail below with reference to the accompanying drawings. while showing

• 1 in the 1a an accumulator according to the invention in a three-dimensional view, in which 1b a perspective schematic view of a battery cell, which is surrounded by a sleeve and in which 1c the sleeve out 1b ,
• 2 in the 2a a schematic cross section through the textile structure in which 2 B a cross-section transverse to the longitudinal axis through a battery cell, which is surrounded by the textile structure, which is arranged on a sleeve in which 2c a cross-section transverse to the longitudinal axis through and a battery cell, on the housing of which the textile structure is glued and in which 2d a cross section through a textile structure according to a second embodiment that has two layers.
• 3 shows a cross section through an accumulator cell, which is surrounded by a textile structure and has a cover.

1 a shows a three-dimensional view of an accumulator 10 with a plurality of accumulator cells 12.i (i=1,2, . . . , N), which are held by a cell holder 13. Empty spaces for accumulator cells are shown, which can be filled with further accumulator cells.

Each accumulator cell has an end face 14 , a bottom face 16 and a lateral surface 18 which runs between the end face 14 and the bottom face 16 . The accumulator cells 12.i are preferably—as in the present case—round cells. For the sake of clarity, in 1a a contact of the accumulator is not shown, by means of which the accumulator cells 12.i are connected in series. The lid holder 13 has Openings 17.i for the respective accumulator cell 12.i (i=1.2,...,N). The openings 17.i are arranged in such a way that the respective end faces Si of the accumulator cells 12.i are accessible. 1 b shows schematically the accumulator cell 12.1, which is surrounded by a sleeve 20.

1c shows the sleeve 20, which has an optional sleeve base body 22 and at least one winding layer made of a textile structure 24. In the present case the structure 24 is a band. The band, which can be a fleece, is wound spirally around the sleeve base body 22 in the present case. In this way, the sleeve base body 22 and thus also the accumulator cell are completely surrounded by the textile structure 24 in the circumferential direction.

2a shows a cross section through the textile structure 24, which has a textile layer 26, here in the form of a fleece layer, an adhesive layer 28 and a heat absorption layer 30. The adhesive layer 28 and the heat absorption layer 30 are arranged on opposite sides of the textile layer 26 .

The textile layer 26 has a layer thickness d ₂₆ of, for example, d ₂₆ =50 μm to 250 μm. The adhesive layer 28 has an adhesive layer thickness d ₂₈ of, for example, up to d ₂₈ =50 μm 250 μm. The heat absorption layer 30 has a thickness d ₃₀ of, for example, d ₃₀ = 250 μm to 500 μm.

The textile layer 26 can consist of felted glass fibers or glass fibers or a polyester nonwoven, which are connected to one another by means of an adhesive. The adhesive layer 28 consists of an acrylic adhesive, for example. The heat absorption layer 30 comprises ettringite powder, which is bound by means of a binder, for example also an acrylate.

2d shows a cross section through a textile structure 24, which has two layers, namely, in addition to the first textile layer 26, a second textile layer 26'. The heat absorption layer 30 is arranged between the textile layers 26, 26'. The adhesive layer 28 is arranged on one of the textile layers 26, 26'.

2 B shows a cross section through the accumulator cell 12.1 with the sleeve 20. It can be seen that the textile structure 24 is wound spirally around the sleeve base body 22. In the present case, the textile structure 24 forms two winding layers. The sleeve 20 has, for example, a sleeve thickness d ₂₀ between 0.5 mm and 2 mm.

2c shows a second view of an accumulator cell 12.1, on the housing 32 of which the textile structure 24 is wound and forms three wound layers.

3 shows a cross section through an accumulator cell 12, which is surrounded by a textile structure 24, which is wound around the accumulator cell 12 in two layers. A cover 34 made of a material containing water of crystallization is arranged on the end face S. The cover 34 lies in a plate plane E of the cell holder 13. The cover 34 is produced, for example, by introducing, in particular pouring, pasty or liquid material containing water of crystallization into the openings 17.i.

Reference List

10

accumulator

12

accumulator cell

13

cell holder

14

face

16

floor space

18

lateral surface

20

sleeve

22

sleeve body

24

textile structure

26

textile layer

28

adhesive layer

30

heat absorption layer

32

Housing

34

Lid

d20

sleeve thickness

d26

ply thickness

d28

Adhesive Layer Thickness

i

running index (accumulator cells)

L

longitudinal axis

QUOTES INCLUDED IN DESCRIPTION

This list of documents cited by the applicant was generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Patent Literature Cited

• DE 102017127337 A1 [0002]
• US 10008704 B2 [0004]
• US7749650B1 [0006]
• US 8361649 B2 [0006]
• US 8541126 B2 [0007]
• US 9093726 B2 [0008]
• US20100151308A1 [0009]
• US 8592076 B2 [0010]

Claims (11)

Accumulator (10) with (a) at least one accumulator cell (12), characterized in that (b) the accumulator cell (12) is surrounded by a flat or three-dimensional textile structure (24), which contains a substance containing water of crystallization, in particular ettringite, in the circumferential direction at least is substantially completely surrounded. Accumulator (10) after claim 1 , characterized in that (a) the textile structure (24) is designed as a hose and a large number of accumulator cells (12) are each surrounded by a hose and/or (b) the textile structure (24) is designed as a sleeve (20). or is part of a sleeve (20), the sleeve (20) surrounding an accumulator cell (12). Accumulator (10) according to one of the preceding claims, characterized in that the textile structure (24) is self-adhesive at least in sections. Accumulator according to one of the preceding claims, characterized by (a) at least one second accumulator cell (12), (b) the at least one second accumulator cell (12) being at least essentially completely surrounded by a second planar or three-dimensional textile structure (24) containing water of crystallization . Accumulator (10) after claim 1 , characterized in that (a) the accumulator cells (12) each have a housing and the textile structure (24) rests against the housing and/or (b) the structure (24) is wound around the accumulator cell (12). Accumulator (10) according to one of the preceding claims, characterized in that (a) at least one of the accumulator cells (12) is a round cell and/or (b) the textile structure (24) is a woven fabric, knitted fabric, knitted fabric, meshwork, stitched fabric, Nonwoven fabric or felt and forms at least two layers. Accumulator (10) according to one of the preceding claims, characterized in that (a) the textile structure (24) is made up of at least one yarn or at least one fiber which contains a substance containing water of crystallization, in particular ettringite, and/or (b) the textile structure (24) has at least two layers and a substance containing water of crystallization, in particular ettringite, is arranged between two layers and/or (c) the textile structure (24) has a coating containing water of crystallization, in particular ettringite. Accumulator (10) according to one of the preceding claims, characterized in that the textile structure (24) contains a phase change material and/or is coated therewith. Accumulator (10) according to one of the preceding claims, characterized in that an outer casing made of metal, in particular aluminum, is arranged around the textile structure. Accumulator (10) according to one of the preceding claims, characterized in that (a) at least a majority of the accumulator cells (12) has an end face and a bottom side lying opposite the end face, which is not completely surrounded by the textile structure (24) and has a have a cover (34) arranged on the end face that contains water of crystallization, in particular containing ettringite, and/or (b) that the accumulator cells (12) are fixed by a plate-shaped cell holder (13), the cell holder having openings for the accumulator cells and the covers (34 ) also lie at least in a plane of the plate of the cell holder (13). Method for producing an accumulator (10), characterized by the steps: (a) wrapping an accumulator cell (12), in particular a housing of an accumulator cell (12), with a flat or three-dimensional textile structure (24) containing a substance containing water of crystallization or (b) wrapping a sleeve (20) with a flat or three-dimensional textile structure (24) which contains a substance containing water of crystallization, in particular ettringite, and introducing an accumulator cell (12) into the sleeve (20).