CN104766941A - Electrodes for battery cells - Google Patents

Abstract

The invention relates to a method for producing an electrode assembly (42) of an accumulator cell (38) accommodated in a housing (40) filled with electrolyte, wherein the following method steps are carried out: A strip-shaped first material, a strip-shaped second material forming the cathode and at least one strip-shaped third material forming the separator are fed to the manufacturing plant. Then, at least the contact tabs (48) of the strip-shaped first material forming the anode and the strip-shaped second material forming the cathode are cut. Next, a layer structure consisting of at least three strips of material is produced. Subsequently, the processed electrode assembly (42) is inserted into the housing (40) containing the electrolyte along the installation direction (52).

Description

Electrodes for battery cells

Background technique

EP 2 355 203 A1 relates to an accumulator and a method for producing such an accumulator. The electrode arrangement includes a first electrode, a second electrode and a separator. The electrode arrangement can be present either as a coil or in a stacked arrangement. The electrode assembly and electrolyte are accommodated in the case. The bag with insulating properties comprises a first side surface, a second side surface, a third side surface, a fourth side surface and a bottom surface, and the bag is also provided with connection holes for the electrolyte. The connection hole for the electrolyte is designed as a through hole and extends from the bottom of the insulating pouch to the lower part of the first and second side surfaces of the battery housing.

KR 2007 0064600 A1 relates to a method for producing electrodes for accumulators, which cuts the electrodes by means of a laser. The electrodes are cut by a laser beam that hits the top surface of the electrodes.

The prior art discloses the cutting of materials or films by means of lasers. It is also disclosed that the contact lugs for the battery cells are wound so that the contact lugs lie on top of each other after the winding.

Contents of the invention

According to the invention, a method is proposed for producing an electrode assembly (Elektrodenensemble) of a battery cell which is accommodated in a casing filled with electrolyte, wherein the following method steps are carried out:

a) delivering a strip-shaped first material forming the anode, a strip-shaped second material forming the cathode, and at least one strip-shaped third material forming the separator to the manufacturing facility;

b) cutting contact tabs of at least the strip-shaped first material forming the anode and the strip-shaped second material forming the cathode;

c) producing a layer structure consisting of at least three strips of material;

d) Insert the processed electrode assembly into the casing containing the electrolyte along the installation direction.

In an advantageous embodiment of the concept on which the invention is based, the substantially strip-shaped material is fed to the peripheral surface of the reel of the winding unit, on which the layered structure of the electrode assembly in wound form is produced.

The in particular layer-structured contact lugs of the electrode assembly are bonded to one another, preferably welded to one another. The layers of the layer structure are freely accessible from the outside for the electrolyte stored in the housing of the battery cell. According to the solution proposed by the invention, the cutting of the contact lug according to method step b) can preferably be carried out according to a corrugation profile. In order to avoid damage to the contact lugs formed on the side of the battery winding, recesses are cut or punched. These recesses are produced uniformly on the anode-side and cathode-side contact lugs and can extend, for example, arcuately in the aluminum or copper material of the two contact lugs on the anode side and the cathode side.

Furthermore, these recesses, which are advantageously located in the end region of the contact lugs of the battery winding, serve to conduct relatively quickly the electrolyte stored in the housing of the battery cell to the pole assembly, so that the corresponding Shorter processing times can be achieved when the battery cells are filled with electrolyte.

The individual contact lugs are pressed together before they are bonded to one another in a material fit, so that an assembly-friendly compact structure results.

Furthermore, in addition to the above-mentioned method for producing an electrode assembly of a battery cell, the invention also relates to a battery cell. The battery cell is characterized in that at least one pole assembly, including the contact lugs, which is arranged in the housing of the battery cell, has recesses for receiving insulating components. The insulating part, which can be installed inside the space provided in the housing of the battery cell, is for example a part called a retainer, the task of which is to insulate the pole assembly from the outside and also to protect the poles Final assembly is protected from mechanical influence. This part is usually made of plastic; its geometry is derived from the design of the battery cell.

The solution proposed by the invention advantageously achieves a decisive reduction in damage to, for example, contact lugs protruding laterally from the battery winding when the wound electrode assembly is inserted, ie inserted, into the housing of the battery cell. risks of. If the contact lugs protrude, for example, from the side of the battery winding, and the battery winding is inserted into the housing from above via the side of the opening substantially in the vertical direction, then during assembly and the protruding contact lugs Undesirable bending, damage, etc. can occur in the case of different lengths, especially at the ends of the contact lugs.

The provision of the recesses in the area of the contact lugs also advantageously achieves that the electrolyte stored in the housing of the battery cell reaches the electrodes more easily and activates the electrochemical process more rapidly. According to the solution proposed by the present invention, by improving the delivery of the electrolyte to the electrode assembly, it is also possible to significantly reduce the filling time required for filling the electrolyte and thus the processing time.

With the solution proposed according to the invention, the sheath edge of the electrode arrangement does not interfere with the winding edge, so that damage to the battery winding in this region can be avoided. According to the solution proposed by the invention, space is provided in the housing of the battery cell which can be used to accommodate other insulating components, for example a cage. The cage is usually a part made of plastic, the task of which is to insulate the electrode assembly from the outside and also to protect it from mechanical influences. The geometry of the cage results from the design of the battery.

The free length of the contact lugs can be significantly shortened by the solution proposed according to the invention for cutting the contact lugs before winding the battery winding. This shortening makes it possible for the electrode assembly to be configured wider overall, ie to use the width of the housing more efficiently, thereby incorporating more active material into the battery cells, which are formed, for example, as battery windings, and This increases energy storage.

Description of drawings

The invention is described in detail below with the aid of the drawings.

In the attached picture:

Figure 1 shows a production plant for the production of electrode assemblies consisting of material present in the form of strips, wherein the electrode assemblies are wound,

Figure 2 shows the assembly of the electrodes into a housing filled with electrolyte,

Figure 3 shows the layer structure of the electrode assembly,

Figure 4 shows the layer structure of the electrode assembly with the contact tabs cut and having a wave-profile,

Figure 5 shows the indentations on both sides of the electrode assembly at the ends of the contact tabs,

Figure 6 shows the layer structure of the electrode assembly cut into layers of different lengths,

FIG. 7 shows the connection of the individual layers of the layer structure one above the other at defined intervals.

Detailed ways

The schematic diagram according to FIG. 1 shows a production system which can be used to produce electrode assemblies from strip-shaped material for anodes, cathodes, and separators.

The production plant 10 comprises a supply section 20 on which electrode assemblies or electrode arrangements can be produced in a roll-to-roll manner. A first material 12 for the production of the anode, a second material 14 for the production of the cathode and at least one third material 16 for the production of the separator are fed to a cutting station 22 in the supply section 20 . The shaping of the preferably strip-shaped third material 16 used to make the divider generally does not require side cutting of the material. Cut the dividers only for their length. This takes place in the feeding and cutting unit 24 . The cutting station 22 contains the alignment of the first material 12 and the second material 14 for the manufacture of the electrodes in such a way that the strip edges are controlled. Furthermore, the laser for cutting is aligned at the cutting position 22 including a protective assembly in order to protect the coating from laser damage and the electrode assembly as a whole from particle damage. A corresponding cleaning unit is also provided, which, for example, enables targeted air blowing and targeted suction. In order to avoid transfer of particles, the cutting point 22 is usually of encapsulated design. A separate unit is required for each electrode, ie for the first material 12 for making the anode and for the second material 14 for making the cathode. To ensure process control, visual inspection systems, for example in the form of cameras, can be used. Feed, alignment, cutting and, if necessary, result control can be carried out via process control.

In FIG. 1 , the supply section 20 is suitably designed so that, in addition to the three strip-shaped materials 12 , 14 , 16 , a fourth material 18 , which is likewise strip-shaped and forms the outer side of the separator, can also be fed to the cutting station 22 . On the peripheral surface 32 of the reel 30 of the winding unit 28, before the strip-shaped materials 12, 14, 16 are optionally 18 formed into a layer structure together, at least three independent strip-shaped The materials 12 , 14 , 16 and optionally the existing fourth material 18 are cut. A coating unit 26 is assigned to the peripheral surface 32 of the reel 30 of the winding unit 28 , by means of which coating unit the layer structure produced on the peripheral surface 32 of the reel 30 can be provided with an adhesive tape. Built-in first and second reels 34 , 36 are located inside the drum 30 .

FIG. 2 shows the electrode assembly prior to assembly in the casing of the battery cell, wherein the casing is filled with electrolyte. According to FIG. 2 , the battery unit 38 includes a housing 40 filled with electrolyte solution and an electrode assembly 42 . The electrode assembly 42 can be an object which is designed as a coil and is referred to as a battery winding, or the electrode assembly 42 can also be an electrode assembly 42 in a stacked arrangement in which case In other words, the individual layers wound up according to FIG. 1 are arranged planarly one above the other.

FIG. 2 shows that the electrode assembly 42 comprises a top cover on its top surface, on which the connection terminal 44 is located. The top cover also has burst valves 46 . According to the perspective view of FIG. 2 , contact lugs 48 , the lug ends of which are marked with the reference numeral 50 , extend on the side of the electrode assembly 42 . According to FIG. 2 , when inserting the electrode assembly 42 into the cavity 54 of the housing 40 along the installation direction 52 there is a risk that the lug end 50 of the contact lug 48 may break off or be otherwise damaged.

Figure 3 shows the layer structure of the electrode assembly.

In FIG. 3 it is shown that the layer structure 56 of the electrode assembly 42 comprises a first material 12 forming an anode, a second material 14 forming a cathode and at least one third material forming a separator. It can be seen from FIG. 3 that the contact lugs 48 shown on the top and bottom sides of the device run essentially flat and are free of cutouts, indentations or the like.

FIG. 4 shows the layer structure of the electrode assembly, the contact lugs of which are cut out extending on the top and bottom sides.

According to FIG. 4 , in addition to the first material 12 forming the anode, the second material 14 forming the cathode, the layer structure 56 also comprises at least one third material 16 forming the separator. Optionally, the layer structure 56 according to FIG. 4 can also have a fourth material 18 serving as a further separating layer.

FIG. 4 shows that the contact lugs 48 extending on the top and bottom sides of the layer structure 56 according to FIG. 4 are provided with corrugated contours 58 . The contact lugs 48 extending substantially parallel to one another on the top and bottom sides of the layer structure 56 shown in FIG. 4 have peaks and valleys that are symmetrical to one another.

The appearance of each contact lug after cutting is shown enlarged in FIG. 5 . FIG. 6 shows that on the upper contact lug 48 made of the second material 14 (that is to say forming the cathode), recesses 60 are respectively provided in the end region in the aluminum material of the cathode. The recess 60 can be a bow-shaped section. In analogy to this, the contact lugs 48 arranged at the bottom in FIG. 5 each have in the area of their corners recesses 62 which are made into the copper material of the lower contact lug 48 serving as an anode.

In addition, the indentation 60 or 62 on the contact tab 48 improves the flow characteristics of the electrolyte stored in the housing 40 to the individual electrode assemblies 42, thereby significantly shortening the electrolyte filling time, which results in a longer Short processing time. It should be mentioned for the sake of completeness that a third and fourth material 16, 18 forming a separator may also be included in the arrangement shown in Fig. 5 .

The recess 60 or 62 in the end region of the contact lug 48 also provides space for further insulating components to be placed in the housing 40 of the battery cell 38 , for example a holder. It can be seen from FIGS. 6 and 7 that the individual layers of the layer structure 56 can be cut to different lengths, for example using laser cutting. In particular, the length of the contact lugs 48 can be adjusted along the thickness of the battery winding, so that after the contact lugs 48 have been pressed together, the individual layers of the layer structure 56 have the same length, thereby saving space.

FIG. 6 shows, for example, that the individual layers 68 , 70 , 72 , 74 , 76 of the layer structure 56 have undergone a length adjustment 66 . Referring to Fig. 6, it can be seen that the built-in layer, that is, the third layer 72 is the shortest, and the second layer 70 and the fourth layer 74 arranged adjacent to this layer have the same length, and they are all shorter than the first layer 68 or the fifth layer. Layer 76 length. If the lengths of the layers 68, 70, 72, 74, 76 are chosen as shown in FIG. 6, a layer layout 78 as shown in FIG. 7 results. Because all the layers 68, 70, 72, 74, 76 of the layer structure 56 terminate at regular intervals, the arrangement shown in FIG. In such a manner that all layers 68, 70, 72, 74, 76 are placed one above the other at defined intervals.

The layer structure 56 formed from the individual layers 68 , 70 , 72 , 74 and 76 in the form of layers 68 , 70 , 72 , 74 and 76 arranged one above the other can be produced either by extrusion using a tool or from a material A mating connection is produced, for example, by means of a pressing device when the individual layers 68 , 70 , 72 , 74 and 76 are joined to one another.

When forming the battery cell 38 as a battery coil, two separator materials or two separator layers are required. They can consist of the same material, but the electrodes must always be wrapped on both sides, because otherwise there will always be contact between the first strip of material 12 (ie the anode) and the second strip of material 14 (ie the cathode). In the case of the layer structures shown in FIGS. 6 and 7 , such separating layers can be, for example, a second layer 70 and a fourth layer 74 .

The invention is not limited to the embodiments described here and the aspects mentioned therein. Rather, there are many variations possible within the scope given by the claims, which are within the purview of a person skilled in the art.

Claims (10)

1., for the manufacture of a method for the electrode general assembly (42) of secondary battery unit (38), the housing (40) that this secondary battery unit is filled with electrolyte held, and has following methods step:

A) the 3rd material (16) forming first material (12) of the band shape of anode, second material (14) of the band shape of formation negative electrode and the band shape of at least one formation separator is flowed to manufacturing equipment (10);

B) to the cutting with the auricle (48) that contacts of the second material (14) of the band shape forming negative electrode of the first material (12) of band shape at least forming anode;

C) Rotating fields (56) be made up of at least three banded materials (12,14,16) is produced;

D) the electrode general assembly (42) processed is inserted into along installation direction (52) in the housing (40) holding electrolyte.

2. in accordance with the method for claim 1, it is characterized in that, carry out according to the circumferential surface (32) of method step conveying a) towards the reel (30) of winder unit (28).

3. in accordance with the method for claim 1, it is characterized in that, the contact auricle (48) of the particularly Rotating fields (56) of described electrode general assembly (42) connects on material fit ground each other, is welded to one another especially together.

4. in accordance with the method for claim 1, it is characterized in that, the layer (68,70,72,74,76) of described Rotating fields (56) keeps arbitrarily being got in housing (40) for electrolyte.

5. according to the method one of the claims Suo Shu, it is characterized in that, according to method step b) cutting of contact auricle (48) is carried out according to ripple-profile (58).

6. according to the method one of the claims Suo Shu, it is characterized in that, cut from anode respectively with the auricle (48) that contacts of negative electrode or stamp out notch (60,62).

7. according to the method one of the claims Suo Shu, it is characterized in that, described notch (60,62) forms the introducing opening being used for electrolyte being caused electrode general assembly (42).

8. according to the method one of the claims Suo Shu, it is characterized in that, suitable length adjustment (66) is carried out to each layer (68,70,72,74,76) of described Rotating fields (56), makes innermost layer (72) be the shortest layer.

9. in accordance with the method for claim 3, it is characterized in that, material fit be bonded with each other before, described contact auricle (48) is compressed.

10. one kind adopts the secondary battery unit (38) made according to the method one of claim 1 ~ 9 Suo Shu, it is characterized in that, at least one electrode general assembly (42) has contact auricle (48), and these contact auricles all include the notch (60,62) of the parts for housing insulation.