Multi-layer protection element for battery

Abstract

The invention relates to a multi-layer protective element (20) for a battery (1) having at least two cells (10) arranged adjacent to one another, the protective element (20) being arrangeable between the cells (10), and the protective element (20) having a compressible core layer (21). According to the invention, the core layer (21) mainly comprises animal hair, the layer thickness of the core layer being 60 to 98% of the total thickness of the protective element. The invention also relates to a battery (1) and to the use of a protective element (20) for a battery (1).

Description

Technical Field

[0001] The invention relates to a multilayer protective element for a battery having at least two battery cells. The invention also relates to a battery having the multilayer protective element and to the use of the protective element as an intermediate layer between two battery cells. Background Art

[0002] US10,840,494B2 discloses a battery having a plurality of prismatic cells in the form of flat cubes, which are arranged adjacent to each other on their larger side surfaces. Starting from an uncharged state, the individual cells expand during charging, wherein the thickness of the individual cells, i.e. the distance between the two larger side surfaces, increases. The expansion of the individual cells arranged adjacent to each other adds up to the overall expansion of the battery, which can cause problems. For example, if the cells are housed in a battery housing, the battery housing may be plastically deformed and possibly damaged due to the expansion of the individual cells. According to US 10,840,494B2, in order to compensate for the expansion of these cells, the protective element arranged between two adjacent cells has a compressible core layer. When the cells expand, the core layer is compressed so that the total thickness of the battery pack consisting of the individual cells and the protective element arranged therebetween does not actually change when the battery is charged. Plastic materials with a lower Shore hardness are suggested as materials for the core layer.

[0003] In addition to compensating for the expansion of the battery cell, the protection element must also fulfill thermal and electrical protection functions. In particular, lithium-ion batteries are highly unstable due to their chemical composition. For example, a local short circuit between the internal electrodes of the battery cell leads to a strong short-circuit current, which quickly heats the battery cell to an extreme degree. This thermal runaway of the battery cell can easily or quickly spread to adjacent batteries. This leads to a chain reaction in which the energy stored in the battery is released explosively. This explosive release of energy can be accompanied by the formation of toxic gases as well as flames and sparks. Therefore, the protection element should have low thermal conductivity, high dielectric strength and high heat (fire) resistance.

[0004] Furthermore, batteries and their components should be easily recyclable. When disposing of used batteries, the multi-layer protective element can be separated from the cell for recycling, but if the individual layers of the protective element are made of different plastic materials, the protective element cannot be recycled in an environmentally friendly manner. Summary of the invention

[0005] The invention is therefore based on the object of providing a protective element for a battery which is compressible and thermally insulating, has a high dielectric strength and is as environmentally friendly as possible.

[0006] The object of the invention is achieved by the combination of features according to claim 1. Exemplary embodiments of the invention can be found in the claims dependent on claim 1.

[0007] According to the invention, the compressible core layer mainly comprises animal hair. In a preferred exemplary embodiment, sheep wool is used. On the one hand, the use of wool for the compressible core layer can provide a protective element (also called a battery compression pad) that is easily compressible and has good compression behavior. On the other hand, very good thermal insulation can be achieved with a low thermal conductivity of less than 0.05 W / mK. In addition, the use of animal hair is environmentally friendly. Animal hair is a natural and renewable product and is easy to recycle. For example, used sheep wool can be used as fertilizer.

[0008] Other types of animal wool besides sheep wool include angora, mohair, cashmere, and alpaca.

[0009] The proportion of animal hair in the core layer can be as high as 100%. For example, the core layer can be composed of up to 80%, 90% or even 100% animal hair. Preferably, the proportion of animal hair in the core layer is 60% to 100%, particularly preferably 80% to 100%. The core layer can be a nonwoven material with multiple layers, which are placed or folded one on top of the other. The core layer can also be made by felting. Felting utilizes the ability of wool to interlock. In particular, pure new animal hair is flame retardant and has excellent thermal insulation value. The animal hair core layer can also be composed of different sublayers. For example, the core layer can include a first nonwoven layer and a second nonwoven layer and a felt layer arranged between the two nonwoven layers.

[0010] The core layer may have a thickness of 80 to 1800 g / m 2 The preferred basis weight is 100 to 1000 g / m 2 Or even 200 to 800g / m 2 .

[0011] According to the invention, the total thickness of the protective element is mainly determined by the layer thickness of the core layer. The thickness of the core layer is 60% to 98% of the total thickness of the protective element.

[0012] The total width of the protective element can be from 0.5 to 12 mm. In an exemplary embodiment, the total thickness is from 1.0 to 10.5 mm. The tolerance is preferably in the range of + / -0.01 mm to + / -1 mm. According to the invention, the layer thickness of the compressible core layer (in the unloaded state) is from 60% to 98% of the total thickness of the protective element, and in a preferred exemplary embodiment, from 1.5 mm to 10 mm. The tolerance is preferably in the range of + / -0.01 mm to + / -1 mm.

[0013] The multilayer protective element may have at least a first barrier layer, which preferably comprises mica. Mica is heat-resistant and fire-resistant. Mica does not refer to a single specific mineral, but to a group of minerals, the so-called mica group, which have a common chemical composition and lattice structure.

[0014] The protective element may have a second barrier layer, wherein the core layer may be arranged between the two barrier layers.One of the two thermal barrier layers may constitute a first outer layer of the protective element.

[0015] The second outer layer of the protective element can be formed by an adhesive layer. The adhesive layer can include a protective release film that must be removed before bonding to the battery cell. If the first outer layer is not designed as an adhesive, one side of the individual battery cells can be laminated with the second outer layer of the protective element during the battery manufacturing process. Since the first outer layer is not designed as an adhesive, each battery cell equipped with a protective element can be arranged next to each other as a battery pack and only then be precisely aligned with each other.

[0016] Another object of the present invention, namely to provide a reliable, safe and environmentally friendly battery, is achieved by claim 9. Therefore, a battery having at least two cells is proposed, wherein a multilayer protection element according to one of claims 1 to 8 is arranged between the cells. The protection element can have a design as provided in the present disclosure. At least one cell can have a prismatic basic shape and preferably a cuboid basic shape. The cell can also be designed as a soft-pack battery. Preferably, all cells of the battery have a prismatic basic shape. In an exemplary embodiment, all cells are designed as soft-pack batteries.

[0017] The invention further provides for the use of a multilayer protective element according to one of claims 1 to 8 as an intermediate layer between two cells of a battery. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is explained in more detail with reference to the exemplary embodiments shown in the accompanying drawings, in which:

[0019] Figure 1 schematically shows a battery having a plurality of battery cells and a plurality of protection elements between the battery cells; and

[0020] Figure 2 The layered structure of the protective element is shown by way of example. DETAILED DESCRIPTION

[0021] Figure 1 A battery is schematically shown, indicated as a whole by 1. The battery may be, for example, a battery for powering an electric vehicle.

[0022] The battery 1 includes a plurality of battery cells 10 . Figure 1Five battery cells 10 are shown; the battery 1 may have fewer battery cells or more battery cells (e.g., ten battery cells). Each battery cell 10 has a basic rectangular parallelepiped shape. The height H of each battery cell 10 is 10 It can be, for example, 50 to 200 mm. Figure 1 The width extending into the drawing plane in the representation of can be, for example, a value of 50 to 300 mm. The thickness of the cell 10 is denoted by D 10 denoted, and may be, for example, 10 to 50 mm.

[0023] The protection element 20 is disposed between every two adjacent battery cells 10. In a preferred embodiment, the thickness D of each protection element 20 is 20 The spatial extension (height and width) of the protection element 20 may correspond to the spatial extension of the battery cell 10. Figure 1 In the exemplary embodiment of the present invention, the height H of the protection element 20 is 20 Slightly smaller than the height H of the battery cell 10 10 .

[0024] Figure 2 The layered structure of the protection element 20 is shown. For the sake of clarity, the individual layers of the multi-layer protection element 20 are shown spaced apart from each other. Figure 1 similar, Figure 2 It's not a scale drawing either.

[0025] The protective element 20 has a compressible core layer 21 made of sheep wool. The core layer 21 is arranged between a first barrier layer 22 and a second barrier layer 23, each of which comprises mica. The first barrier layer 22 is a first outer layer of the protective element 20.

[0026] The second barrier layer 23 is located between the core layer 21 and the adhesive layer 24 including the release film 25. The adhesive layer 24 (with the release film 25) forms a second outer layer of the protective element 20. Further adhesive layers 26, 27 are provided between the barrier layers 22, 23 and the core layer 21.

[0027] In order to bond the protection element 20 to the battery cell 10, the release film 25 is peeled off so that the adhesive of the adhesive layer 24 is exposed, and the adhesive layer 24 can be placed on the relevant battery cell 10. The battery cell 10 and the protection element 10 adhered thereto then form a unit, which can then be arranged adjacent to each other in a package / stack with other units produced in this way. Since the outer surface of each unit is non-adhesive, they can still be aligned with each other even when they are already in a package or stack.

[0028] Reference numerals list

[0029] 1 Battery

[0030] 10 cells

[0031] 20 Protection components

[0032] 21 Core layer

[0033] 22 First barrier layer

[0034] 23 Second barrier layer

[0035] 24 Adhesive layer

[0036] 25 Release film

[0037] 26 Adhesive layer

[0038] 27 Adhesive layer

Claims

1. A multilayer protective element (20) for a battery (1), the battery (1) having at least two battery cells (10) arranged adjacent to each other, wherein the protective element (20) can be arranged between the battery cells (10), and wherein the protective element (20) has a compressible core layer (21), characterized in that: The core layer (21) mainly comprises animal hair and the layer thickness of the core layer (21) is 60% to 98% of the total thickness of the protective element (20).

2. The protection element (20) according to claim 1, characterized in that The proportion of animal hair in the core layer (21) is 60% to 100%.

3. The protection element (20) according to claim 1 or 2, characterized in that: The core layer (21) comprises sheep wool.

4. The protection element (20) according to any one of claims 1 to 3, characterized in that: The core layer (21) is a non-woven material or a felt made of animal hair.

5. The protection element (20) according to any one of claims 1 to 4, characterized in that: The core layer (21) has a thickness of 200 g / m 2 Up to 1000g / m 2 The basis weight.

6. The protection element (20) according to any one of claims 1 to 5, characterized in that: A first barrier layer (22) is provided, preferably comprising mica.

7. The protection element (20) according to claim 6, characterized in that A second barrier layer (23) is provided, wherein the core layer (21) is disposed between the first barrier layer (22) and the second barrier layer (23).

8. The protection element (20) according to claim 7, characterized in that One of the two thermal barrier layers (22, 23) is a first outer layer of the protective element (20).

9. The protection element (20) according to any one of claims 1 to 8, characterized in that The second outer layer is formed of an adhesive layer (24) having a release film (25).

10. A battery (1) having at least two battery cells (10), wherein a multilayer protective element (20) according to any one of claims 1 to 9 is arranged between the battery cells.

11. Use of the multilayer protective element (20) according to any one of claims 1 to 9 for insertion between two battery cells (10) of a battery (1).

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