Method of producing an electrode-separator winding, electrode-separator winding and button cell with such a winding

Abstract

A method of producing an electrode-separator winding includes feeding a first current collector, feeding a second current collector, feeding two separators in strip form to a winding device, and winding the first and second current collectors and the separators to form a winding with a sequence, wherein a contact strip is welded on at least one of the contact sections of the current collectors, or at least one of the contact sections is folded over to form a contact strip, and at least one of the separators is reinforced in at least one risk region in which the at least one separator within the completed electrode-separator winding lies against the at least one contact section in which the contact strip is welded on or against the at least one contact section folded over to form a contact strip.

Claims

1. A method of producing an electrode-separator winding comprising: feeding a first current collector in strip form, which is divided in the longitudinal direction into mass sections covered with a positive electrode material and, arranged between the mass sections, contact sections not covered with the electrode material, to a winding device, feeding a second current collector in strip form, which is divided in the longitudinal direction into mass sections covered with a negative electrode material and, arranged between the mass sections, contact sections not covered with the electrode material, to the winding device, feeding two separators in strip form to the winding device, and winding up the first current collector in strip form, the second current collector in strip form and the separators in the winding device to form a winding with the sequence first current collector/separator/second current collector/separator or second current collector/separator/first current collector/separator, wherein a contact strip is welded on in at least one of the contact sections for the electrical contacting of the current collectors, or at least one of the contact sections is folded over to form a contact strip for the electrical contacting of the current collectors, and at least one of the separators is reinforced in a Z-shaped folding and at least one risk region in which the at least one separator within the completed electrode-separator winding lies against the at least one contact section in which the contact strip is welded on or against the at least one contact section folded over to form a contact strip.

2. The method according to claim 1, further comprising: the first current collector and second current collector are cut through in the region of two contact sections, each forming a contact section at the end, and the separators are cut through, each forming a separator section at the end; and the electrode-separator winding is completed by winding up the contact sections at the ends and the separator sections at the ends.

3. The method according to claim 2, with the additional step that to form the contact strip for the electrical contacting of the current collectors, at least one of the contact sections at the ends is folded over.

4. The method according to claim 1, further comprising: to reinforce the separators, in the at least one risk region a film that can be welded to the separators is fixed in one or more layers on the separator.

5. The method according to claim 4, with the additional step that the fixing is performed by welding.

6. The method according to claim 4, wherein a film of the same material as the separator is used as the film.

7. The method according to claim 1, wherein the at least one reinforcement is formed by Z folding.

8. An electrode-separator winding, comprising: a first current collector in strip form, which is divided in the longitudinal direction into at least one mass section covered with a positive electrode material and at least one contact section not covered with the electrode material, a second current collector in strip form, which is divided in the longitudinal direction into at least one mass section covered with a negative electrode material and at least one contact section not covered with the electrode material, two separators in strip form wherein the first current collector in strip form, the second current collector in strip form and the separators are wound up to form a winding with the sequence first current collector/separator/second current collector/separator or second current collector/separator/first current collector/separator, a contact strip is welded on in at least one of the contact sections for the electrical contacting of the current collectors, or at least one of the contact sections is folded over to form a contact strip for the electrical contacting of the current collectors, and at least one of the separators is reinforced in a Z-shaped folding and at least one risk region in which the at least one separator within the electrode-separator winding lies against the at least one contact section in which the contact strip is welded on or against the at least one contact section folded over to form a contact strip.

9. A button cell comprising the electrode-separator winding according to claim 8.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically illustrates a first example of the method, in which two separators are each reinforced in a risk region by fixing on the separators films that can be welded to the separators. In the risk regions, after completion of the electrode-separator winding, the separators are respectively in contact with contact sections of current collectors in which contact strips are welded on. The fixing is ensured by welding the films to the separator.

(2) FIG. 2 schematically illustrates a second example of the method, in which two separators are each reinforced in a risk region by folding over the separators at the ends. In the risk regions, after completion of the electrode-separator winding, the separators are respectively in contact with contact sections of current collectors in which contact strips are welded on.

(3) FIG. 3 schematically illustrates a third example of the method, in which two separators are each reinforced in a risk region by a Z folding of the separators. In the risk regions, after completion of the electrode-separator winding, the separators are respectively in contact with contact sections of current collectors in which contact strips are welded on.

(4) FIG. 4 schematically illustrates a fourth example of the method, in which two separators are each reinforced in a risk region by folding over the separators at the ends. In the risk regions, after completion of the electrode-separator winding, the separators are respectively in contact with contact sections of current collectors in which the current collectors are folded over by a folding along two folding lines each aligned at an angle of 45° to the main direction of extent of the current collectors in strip form to form contact strips for the electrical contacting of the current collectors.

(5) FIG. 5 schematically illustrates a fifth example of the method, in which two separators are each reinforced in a risk region by a Z folding of the separators. In the risk regions, after completion of the electrode-separator winding, the separators are respectively in contact with contact sections of current collectors in which the current collectors are folded over by a folding along two folding lines each aligned at an angle of 45° to the main direction of extent of the current collectors in strip form to form contact strips for the electrical contacting of the current collectors.

DETAILED DESCRIPTION

(6) Our method comprises the following steps:

(7) feeding a first current collector in strip form, which is divided in the longitudinal direction into mass sections covered with a positive electrode material and, arranged between the mass sections, contact sections not covered with the electrode material, to a winding device,

(8) feeding a second current collector in strip form, which is divided in the longitudinal direction into mass sections covered with a negative electrode material and, arranged between the mass sections, contact sections not covered with the electrode material, to the winding device,

(9) feeding two separators in strip form to the winding device, and

(10) winding up the first current collector in strip form, the second current collector in strip form and the separators in the winding device to form a winding with the sequence first current collector/separator/second current collector/separator or second current collector/separator/first current collector/separator.

(11) To this extent, the method does not differ from known methods as far as the method steps described are concerned or as far as the materials and items used are concerned. Thus, for example, the materials, current collectors and separators mentioned at the beginning come into consideration as electrode materials, current collectors and separators.

(12) Likewise as known, we provided that a contact strip is welded on in at least one of the contact sections for the electrical contacting of the current collectors, or at least one of the contact sections is folded over to form a contact strip for the electrical contacting of the current collectors. For this, it is possible, for example, to revert to the procedure known from WO 2010/146154 A2.

(13) On the other hand, our method is distinguished from the known method in that:

(14) at least one of the separators is reinforced in at least one risk region in which the at least one separator within the completed electrode-separator winding lies against the at least one contact section in which the contact strip is welded on or against the at least one contact section folded over to form a contact strip.

(15) The term “risk region” has already been explained. Here, it is a region of the separator exposed to an increased risk of damage because of direct contact with a contact strip as a consequence of which a short-circuit could occur.

(16) A reinforcement of the separator in the risk region means that the separator has a greater thickness in the risk region. As a result, the described risk of a short-circuit can be countered just as well as with Kapton tapes. However, the disadvantages these entail do not necessarily occur, which is further explained below.

(17) Particularly preferably, that the method is distinguished by at least one of the following:

(18) the first current collector and second current collector are cut through in the region of two contact sections, each forming a contact section at the end, and the separators are cut through, to each form a separator section at the end;

(19) the electrode-separator winding is completed by winding up the contact sections at the ends and the separator sections at the ends.

(20) Particularly preferably, the method is distinguished by one of the following:

(21) to form the contact strip for the electrical contacting of the current collectors, at least one of the contact sections at the ends is folded over;

(22) the at least one contact section in which the contact strip is welded on is a contact section at the end or else a contact section not at the end, arranged between two mass sections.

(23) In examples in which a contact strip is welded on in at least one of the contact sections for the electrical contacting of the current collectors, it is usually preferred that the contact strip is welded on at an angle of 45° to 135° to the main direction of extent of the current collector in strip form.

(24) In examples in which at least one of the contact sections at the ends is folded over to form a contact strip for the electrical contacting of the current collectors, it is usually preferred that the at least one contact section at the end is folded over by a folding along a folding line aligned at an angle of 10° to 80° to the main direction of extent of the current collector in strip form. It then preferably comprises a folded-over subsection in strip form and a non-folded-over subsection.

(25) Thus, the main direction of the extent of the current collector in strip form means the direction in which the current collector has its greatest extent in the state in which it is laid out flat.

(26) Preferably, both separators in strip form are reinforced in the risk regions, not only one of the separators.

(27) It is preferred that, to reinforce the separators, in the at least one risk region a film that can be welded to the separators is fixed in one or more layers on the separator. The fixing is preferably performed by welding the film to the separator.

(28) Particularly preferably, a film of the same material as the separator is used as the film.

(29) Further preferably, the reinforcements are formed by a folding of the separators, in particular by a Z folding.

(30) The electrode-separator winding always comprises

(31) a first current collector in strip form, which is divided in the longitudinal direction into at least one mass section covered with a positive electrode material and at least one contact section not covered with the electrode material,

(32) a second current collector in strip form, which is divided in the longitudinal direction into at least one mass section covered with a negative electrode material and at least one contact section not covered with the electrode material, and

(33) two separators in strip form

(34) wherein

(35) the first current collector in strip form, the second current collector in strip form and the separators are wound up to form a winding with the sequence first current collector/separator/second current collector/separator or second current collector/separator/first current collector/separator, and

(36) a contact strip is welded on in at least one of the contact sections for the electrical contacting of the current collectors, or at least one of the contact sections is folded over to form a contact strip for the electrical contacting of the current collectors.

(37) The electrode-separator winding can be produced by the method described above. It is correspondingly distinguished in particular in that:

(38) at least one of the separators is reinforced in at least one risk region in which the at least one separator within the electrode-separator winding lies against the at least one contact section in which the contact strip is welded on or against the at least one contact section folded over to form a contact strip.

(39) Preferred examples of the electrode-separator winding are evident from the above description of the method, both as far as the materials and items used are concerned and as far as the various examples of the reinforcement are concerned.

(40) Any button cell comprising the described electrode-separator winding, in particular the electrode-separator winding that can be produced by the method, is the subject of this disclosure.

(41) The button cell may, for example, have a housing as in FIG. 4 of WO 2010/089152 A1 or as in FIG. 1 of WO 2010/146154 A2. The housings each have circular bases. The electrode-separator winding described is arranged in the housings such that its end faces face in the direction of the circular bases, possibly even lie flat against them.

(42) The welding of the housing parts to the contact strips may, for example, be performed as shown in FIGS. 1A and 1B of WO 2010/146154 A2.

(43) Sealing the button cell is preferably performed by a customary injection-moulded or foil seal.

(44) Further features, details and advantages emerge from the appended claims and the abstract, the wording of both of which is made the content of the description by reference, the following description of preferred examples and also on the basis of the drawings.

(45) According to the method shown in FIG. 1, a first current collector in strip form 101, which is divided in the longitudinal direction into mass sections covered with a positive electrode material (sections 101a and 101c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 101b), a second current collector in strip form 102, which is divided in the longitudinal direction into mass sections covered with a negative electrode material (sections 102a and 102c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 102b), and two separators in strip form 103 and 104 are processed to form an electrode-separator winding 100.

(46) The two separators 103 and 104 are reinforced in the risk regions 103a and 104a (shown hatched) by the films 105 and 106. The films 105 and 106 are fixed on the separators 103 and 104 by welding. In the risk regions 103a and 104a, after completion of the electrode-separator winding, the separators 103 and 104 lie against the contact sections 101b and 102b of the current collectors 101 and 102. In these contact sections 101b and 102b, the contact strips 107 and 108 are welded on. As a consequence of the reinforcement, the risk of a short-circuit in the risk regions 103a and 104a can be minimized.

(47) According to the method shown in FIG. 2, a first current collector in strip form 101, which is divided in the longitudinal direction into mass sections covered with a positive electrode material (sections 101a and 101c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 101b), a second current collector in strip form 102, which is divided in the longitudinal direction into mass sections covered with a negative electrode material (see sections 102a and 102c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 102b), and two separators in strip form 103 and 104 are processed to form an electrode-separator winding 100.

(48) The two separators 103 and 104 are reinforced in the risk regions 103a and 104a (shown hatched) by the films 105 and 106. The films 105 and 106 are sections of the separators 103 and 104 that have been simply folded over at their ends. In the risk regions 103a and 104a, after completion of the electrode-separator winding, the separators 103 and 104 lie against the contact sections 101b and 102b of the current collectors 101 and 102. In these contact sections 101b and 102b, the contact strips 107 and 108 are welded on. As a consequence of the reinforcement, the risk of a short-circuit in the risk regions 103a and 104a can be minimized.

(49) According to the method shown in FIG. 3, a first current collector in strip form 101, which is divided in the longitudinal direction into mass sections covered with a positive electrode material (sections 101a and 101c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 101b), a second current collector in strip form 102, which is divided in the longitudinal direction into mass sections covered with a negative electrode material (sections 102a and 102c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 102b), and two separators in strip form 103 and 104 are processed to form an electrode-separator winding 100.

(50) The two separators 103 and 104 are reinforced in the risk regions 103a and 104a (shown hatched) by the films 105 and 106. The films 105 and 106 are sections of the separators 103 and 104 that have been folded over in the form of a Z. In the risk regions 103a and 104a, after completion of the electrode-separator winding, the separators 103 and 104 lie against the contact sections 101b and 102b of the current collectors 101 and 102. In these contact sections 101b and 102b, the contact strips 107 and 108 are welded on. As a consequence of the reinforcement, the risk of a short-circuit in the risk regions 103a and 104a can be minimized.

(51) According to the method shown in FIG. 4, a first current collector in strip form 101, which is divided in the longitudinal direction into mass sections covered with a positive electrode material (sections 101a and 101c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 101b), a second current collector in strip form 102, which is divided in the longitudinal direction into mass sections covered with a negative electrode material (sections 102a and 102c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 102b), and two separators in strip form 103 and 104 are processed to form an electrode-separator winding 100.

(52) The two separators 103 and 104 are reinforced in the risk regions 103a and 104a (shown hatched) by the films 105 and 106. The films 105 and 106 are sections of the separators 103 and 104 that have been simply folded over at their ends. In the risk regions 103a and 104a, after completion of the electrode-separator winding, the separators 103 and 104 lie against the contact sections 101b and 102b of the current collectors 101 and 102. In these contact sections 101b and 102b, the current collectors 101 and 102 are respectively folded over by a folding along two folding lines 109 and 110 aligned at an angle of about 45° to the main direction of extent of the current collectors in strip form 101 and 102 to form contact strips 107 and 108 for the electrical contacting of the current collectors 101 and 102. As a consequence of the reinforcement, the risk of a short-circuit in the risk regions 103a and 104a can be minimized.

(53) According to the method shown in FIG. 5, a first current collector in strip form 101, which is divided in the longitudinal direction into mass sections covered with a positive electrode material (sections 101a and 101c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 101b), a second current collector in strip form 102, which is divided in the longitudinal direction into mass sections covered with a negative electrode material (sections 102a and 102c) and, arranged between the mass sections, contact sections not covered with the electrode material (section 102b), and two separators in strip form 103 and 104 are processed to form an electrode-separator winding 100.

(54) The two separators 103 and 104 are reinforced in the risk regions 103a and 104a (shown hatched) by the films 105 and 106. The films 105 and 106 are sections of the separators 103 and 104 that have been folded over in the form of a Z. In the risk regions 103a and 104a, after completion of the electrode-separator winding, the separators 103 and 104 lie against the contact sections 101b and 102b of the current collectors 101 and 102. In these contact sections 101b and 102b, the current collectors 101 and 102 are respectively folded over by a folding along two folding lines 109 and 110 aligned at an angle of about 45° to the main direction of extent of the current collectors in strip form 101 and 102 to form contact strips 107 and 108 for the electrical contacting of the current collectors 101 and 102. As a consequence of the reinforcement, the risk of a short-circuit in the risk regions 103a and 104a can be minimized