Method for producing battery module having plurality of cells arranged in cell stack

Abstract

The invention relates to a method for producing a battery module (100) having a plurality of cells (110) arranged in a cell stack, comprising the following steps: arranging partially charged cells (110) in a cell stack, a pressure plate (120) being also arranged on each of the opposite ends of the cell stack; temporarily pressing (P) the stack of cells; sleeving at least one closed clamping band (130) such that the clamping band (130) surrounds the stack of cells including the pressure plate (120); -terminating the temporary pressing (P), whereby the cell stack is expanded and the clamping strap (130) is tightened; -charging the cell (110), whereby the cell (110) expands and further tensions the clamping strap (130).

Description

Technical Field

[0001] The invention relates to a method for producing a battery module having a plurality of battery cells arranged in a cell stack. Background Art

[0002] The battery module in question has a plurality of storage cells or storage cells, namely at least two, arranged in a cell stack. The cells must be held together in a suitable manner. This can be achieved by means of at least one clamping element, which presses or clamps the cells together. The pressure applied to the cells by means of the clamping elements can also have a positive effect on their service life. Preferably, the battery module is a battery module for a power battery to drive a motor vehicle.

[0003] DE 10 2012 214 258 A1 describes a battery module having at least two battery cells and a clamping element for clamping the battery cells relative to one another. The clamping element comprises a textile material and can be designed as a completely circumferential band, i.e. as a continuous band. The invention also relates to a method for producing a battery module, wherein the battery cells are first clamped or pressed against one another and then the clamping element designed as a continuous band is placed over the battery cells. Summary of the invention

[0004] The object of the present invention is to specify an improved production method for an associated battery module, which production method is in particular also suitable for series production.

[0005] This object is achieved by the method according to the invention according to claim 1. Advantageous developments and embodiments of the method according to the invention are apparent from the dependent claims, the following description of the invention (which also includes the features described by way of example and as an option) and the drawings.

[0006] The method according to the present invention provides the following steps:

[0007] - arranging the partially charged cells into a cell stack, and arranging end plates or pressure plates at opposite ends of the cell stack;

[0008] - Temporarily compress the battery cell stack;

[0009] - at least one closed clamping band / clamping band is placed on the compressed cell stack so that the clamping band surrounds or encircles the cell stack together with the two pressure plates;

[0010] - ending the temporary compression, thereby expanding the cell stack (due to elastic restoring) and tightening the tightening band;

[0011] The cell is charged, thereby causing it to expand and further tightening the tightening strap.

[0012] The battery cell is preferably a prismatic battery cell and in particular a cuboid battery cell. The battery cell is first partially charged. This means that the battery cell is not fully charged or is only incompletely charged, preferably only 10% to 50% (10% to 50% SOC), in particular only 20% to 30% (20% to 30% SOC) of the maximum charge capacity (=100%). When stacking, an intermediate layer, such as a fireproof layer and / or an intermediate plate, can be arranged between the battery cells. Preferably, a flat stack with a horizontal stacking direction is formed. The battery stack is compressed in the stacking direction, for example by means of a hydraulic clamping device. In particular, the compression is performed in such a way that the outer periphery of the battery stack is smaller than the inner periphery of the clamping band to be installed. Multiple clamping bands, preferably two clamping bands, can be installed on the compressed battery stack, and these clamping bands are installed in particular from the opposite stacking side or module side.

[0013] The tightening belt loop to be mounted is a closed loop with a predetermined or preset circumference. The tightening belt loop is preferably formed by a flexible and almost inelastic belt material or rope material, in particular by a flat belt material with a width of 5mm to 20mm. The tightening belt loop is preferably formed by a fiber material, in particular by a belt material or rope material containing continuous glass fibers or carbon fibers, such as a UD belt or similar material. The belt material or rope material can be provided as a semi-finished product, cut to a certain length and processed into a tightening belt loop in a suitable manner. The belt material or rope material can be formed only by fibers (dry fibers), which are connected in a suitable manner, for example, by means of sutures. The belt material or rope material can also have a plastic matrix, in particular a thermoplastic plastic matrix, which protects the fibers or filaments and prevents tearing. The tightening belt loop can be formed by a single turn or a single layer of belt material or rope material or multiple turns or multiple layers of belt material or rope material.

[0014] The method according to the invention provides for the use of at least one prefabricated clamping band ring. On the one hand, this enables the clamping band length to be precisely set and the tightening achieved thereby. On the other hand, a complex winding process with band ends for fixing is not necessary. In order to simplify the installation of the clamping band ring, the invention utilizes the effect that the battery cells increase their volume or expand during the charging process, which is also called swelling or swelling effect. During charging, the battery cells are preferably fully charged (i.e. approximately 100%), in which case the battery stack or battery module reaches its predetermined installation length due to the swelling effect, which means the installation length in the stacking direction.

[0015] Preferably, at least one mounting auxiliary device is used for mounting the tightening band ring, which is temporarily fixed to at least one pressing plate. The temporary and detachable fixing can be achieved by means of one or more plug-in connections or threaded connections. This mounting auxiliary device, especially in combination with the pressing plate, preferably forms at least one edgeless slide rail for the tightening band ring to be mounted, and especially has at least one sliding surface for the tightening band ring, which is designed to facilitate sliding, for example, smooth or even polished. After mounting, at least one mounting auxiliary device is removed again. This mounting auxiliary device is therefore similar to an installation auxiliary device or an installation auxiliary tool, which is especially configured to be reusable. The mounting auxiliary device can be made of plastic or metal.

[0016] Preferably, a plurality of mounting aids are used, for example two or four mounting aids, which are (temporarily) fixed at the corners or in the corner region of the pressure plate and are in particular provided to form a non-edge guide rail, preferably in the corner region, for the clamping band to be mounted. Preferably, four rod-shaped mounting aids are used for mounting the clamping band, which are each designed with a pin-shaped element and are thereby (temporarily) fixed in holes provided for this purpose, in particular corner holes, on the pressure plate (see below).

[0017] Within the scope of the invention, not only the features described above but also the features to be explained below can be used not only in the respectively described feature combination but also in other feature combinations or individually. This also applies to the features shown in the drawings. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] The invention is explained in detail below in a non-restrictive manner with reference to the drawings. The features shown in the drawings and / or explained below may also be general features of the invention regardless of a specific feature combination and improve the invention accordingly.

[0019] Figure 1 A battery module manufactured according to the present invention is shown.

[0020] Figure 2 Shown for manufacturing Figure 1 Steps for the battery module.

[0021] Figure 3 Schematically showing the manufacturing process of the set auxiliary device Figure 1 Use of battery modules. DETAILED DESCRIPTION

[0022] exist Figure 1The battery module 100 shown in the figure is a battery cell assembly comprising a plurality of horizontally stacked battery cells 110. A pressure plate 120 is arranged at the opposite ends of the battery cell stack. In addition, there are two tightening bands 130 under tension, which surround or clamp and compress the battery cell 110 and the pressure plate 120. The tightening band 130 comprises a plurality of closed loops, which are particularly constructed in the same manner. In the stacking direction, the battery module 100 has a length L.

[0023] The production of the battery module 100 includes a plurality of steps. Figure 2 to describe.

[0024] - Step 10: Arrange or arrange the partially charged battery cells 110 into a battery cell stack and arrange two pressing plates 120. In the stacking direction, the battery cell stack (including the pressing plates 120) has a first length L1.

[0025] - Step 20: As shown by arrow P, temporarily compress the battery cell stack, wherein the initial first length L1 is reduced to a second length L2, wherein: L2<L1.

[0026] - Step 30: Install the tightening belt ring 130 .

[0027] - Step 40: The temporary compression is terminated, whereby the cell stack expands to a third length L3 and the tightening band ring 130 is tightened, wherein: L1 ≥ L3 > L2.

[0028] - Step 50: Charge the battery cells 110, thereby expanding the battery cell stack to a fourth length L4 and further tightening the tightening band 130. Wherein: L4>L3. Preferably, the battery cells 110 are fully charged, wherein the battery cell stack or the battery module 100 reaches its predetermined installation length.

[0029] like Figure 3 As shown, a mounting aid 200 can be used to mount the tightening belt ring 130. The mounting aid 200 is temporarily fixed on the pressure plate 120. Preferably, four rod-shaped mounting aids 200 are provided, each of which has a pin-shaped member 210. The pressure plate 120 is configured with a hole or a corner hole 125 in the corner (see also Figure 1 ), the pin-shaped member 210 can be inserted or screwed into the hole or corner hole 125, that is, the hole 125 can be configured as an insertion hole or a threaded hole. Preferably, the hole 125 is implemented as a metal socket, especially in the case of a pressure plate 120 made of plastic. Figure 3 As shown, the set auxiliary device 200 forms a non-edge slideway for the tightening belt ring 130 to be set in the corner area of ​​the pressure plate 120. After the tightening belt ring 130 is pushed and set to the specified position, as shown in FIG. Figure 3As shown by the dotted line, the set assisting device 200 is removed.

[0030] exist Figure 1 The two clamping band rings 130 shown in the figure can be inserted from the same stack side or module side in the above-described manner. However, it is preferably provided that the clamping band rings 130 are inserted from the opposite stack side or module side, that is, the pressure plate 120 is respectively configured with four holes 125.

Claims

1. A method for manufacturing a battery module (100), the battery module having a plurality of battery cells (110) arranged in a battery cell stack, the method comprising the following steps: - arranging the partially charged battery cells (110) into a battery cell stack, and arranging pressure plates (120) at opposite ends of the battery cell stack; - Temporarily compress (P) the battery cell stack; - at least one closed tightening band ring (130) is installed so that the tightening band ring (130) surrounds the battery cell stack and the pressure plate (120); - ending the temporary compression (P), thereby expanding the cell stack and tightening the tightening band (130); - Charging the battery cell (110), thereby causing the battery cell (110) to expand and further tightening the tightening band (130).

2. The method according to claim 1, It is characterized in that During charging, the battery cells (110) are fully charged, in which case the battery cell stack reaches its predetermined installation length.

3. The method according to any one of the preceding claims, It is characterized in that At least one auxiliary fitting device (200) is used to fit the tightening band (130), which is temporarily fixed to at least one pressure plate (120).

4. The method according to claim 3, It is characterized in that A plurality of set-up aids (200) are used, which are fixed at the corners of the press plate (120).

5. A method according to claim 3 or 4, It is characterized in that Four rod-shaped insertion aids (200) are used, each of which is designed with a pin-shaped element (210) and is fixed by means of the pin in a hole (125) provided for this purpose on the pressure plate (120).

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