DE102010007595A1 - Connecting device for mechanical and electrical interconnection of e.g. lithium polymer cells to provide multi-cell accumulator, has boards arranged such that contacts of galvanic elements are clamped between contacting areas and one board - Google Patents

Abstract

The device has a printed circuit board (PCB-A) provided with contacting areas (A1, A2) of a contact e.g. thick copper layer, adjacent to an electrode contact-passage opening (S). Another printed circuit board (PCB-B) is stretchable against the former circuit board. The circuit boards are arranged such that electrode contacts (L1, L2) of galvanic elements (Z1, Z2) are clamped between the contacting areas and the latter circuit board. A spacing (d) is formed between the circuit boards in a tensed state.

Description

Technical area:

The invention relates to a connecting device for mechanical and electrical connection or interconnection of individual galvanic elements, which have led out of these or protruding electrode contacts to provide a multi-cell battery or a multi-cell accumulator.

To achieve higher performance or greater energy storage capacity similar galvanic elements in the form of individual battery or accumulator cells are connected together as needed in groups to cell packs.

Shapes in which the individual cells used in practice are executed are very diverse. For each form there are different possibilities and procedures to connect and contact each other. In addition to button cells, there are various round cell types, as well as prismatic cells and so-called flat cells. The latter design is commonly referred to as a pouch cell (German Beutel cell) or as a coffee pack. At present it is predominantly, but not exclusively, used in the field of lithium polymer accumulators. This form is not standardized and can be customized to customer requirements. Characteristic are the lead out, protruding from the cell electrodes, which are usually designed as contact straps consisting of metal strips.

Low-cost mass production of lithium-ion batteries allows the use of this technology in areas with higher power requirements, such. As the drive technology with, for example, auxiliary drives for wheelchairs and bicycles, partial, full hybrid and full electric drives in the field of motor vehicles.

In the future, increasingly larger quantities of larger accumulators with higher power and energy storage density will be needed, which meet the price conditions for mass production. At present and in all likelihood in the medium term future, wound flat cells, currently represented in the form of lithium polymer cells but also iron phosphate and nanophosphate cells, will preferably be used. The advantage of these cells to the previously standardized prismatic and round cells from the mass production of mobile applications, eg. As mobile phone and portable computer, is in their relatively simple and inexpensive individual customization in shape and size to specific customer requirements. As a result, the highest capacities and maximum current levels can currently be found among flat cells, making them particularly suitable for applications in higher power ranges.

State of the art

For the interconnection of bag cells, there have hitherto generally been four possibilities: direct soldering of the contact tabs or electrode contacts of the individual cells with one another. Soldering the electrode contacts on a circuit board, through which the cells are interconnected. Direct welding of the electrode contacts of the individual cells with each other. Connecting the individual electrode contacts with each other by Klemmverbindungselemente.

The contact tabs of bag or flat cells usually consist of metal alloys, which can be soldered, if at all, only with special for the metal alloy solder. These metal alloys can not only be different between cell manufacturers or individual cell series and can be changed without manufacturer's announcement, but the metal alloys are often already designed differently between the two electrode contacts of a single cell. Thus, various equipment must be kept ready for this connection and, if necessary, always be purchased again. Employees always have to learn new soldering techniques. Nevertheless, a secure solder joint can not be guaranteed right away.

Apart from this, the soldering, whether the cell contacts are directly connected to each other or soldered to a circuit board, represents a very time-consuming form of cell assembly. Finally, aggravating the fact that a damaging for the cell heat input is possible by the soldering process. In addition, there is a general risk that hot solder drips on the cell and it is damaged.

A circuit board assembly in which the contact tabs or electrode contacts of the cells are soldered onto the solder pads of a circuit board, in contrast to a direct connection of the cell contacts with each other in bag cells several advantages: First, an interconnection of the individual cells to a particular parallel and serial combination is straight In cell packages with multiple cells may be geometrically easier and cleaner solvable. In addition, the contacts can be better insulated afterwards. In addition, a space-saving construction is possible.

Furthermore, further connecting elements, such. B. strands for Single cell voltage taps, soldered easier, instead of having to solder them as a third element to the electrode contacts. Also, the circuit board may carry other circuit elements, such as electronic assemblies or fuses, instead of having to attach them separately, as in a purely direct electrode contacting. Nevertheless, the disadvantages of a soldered connection are retained to the full extent.

During welding, the heat input is lower than during soldering. However, here too great difficulties arise due to the material pairings to be welded and, above all, due to the possibilities of conventional cell welding machines, to achieve specific positions for welding spots spatially. As a result, welding as a contact-type form in pouch cells is extremely rarely used.

DE 20 2004 015 179 U1 describes such a solderless contact connector for electrically connecting a plurality of lithium polymer cells in a parallel connection. The individual electrode contacts are pressed together by means of conductor bridges and Gewindeklötzchen and thus electrically connected to each other.

WO 2007/121445 A2 describes an arrangement in which flat electrode contacts are guided from below through slit-shaped openings of a plate made of a non-conductive material and bent over on the opposite upper side and screwed by means of connecting elements. For screwing screws are guided by holes formed in the connection elements and the electrode contacts and screwed into flat counter-elements, which are arranged above the plate between the openings.

The known mechanical mounting options that achieve a connection by clamping or pressing, consist of many individual elements and require a fairly high installation costs and a lot of space. But above all, because of their complex geometries and the relatively large number of individual elements that must be individually adapted for each cell type and sometimes each cell package, consuming in the production, procurement and warehousing and have compared to the soldering techniques only rarely decisive advantages, so that they only come in a few cases for practical application.

Clamping would in principle be better than soldering, but the known clamping methods are too expensive and too expensive for most practical applications. Although such clamp connections circumvent the disadvantages of the substance-connecting techniques, however, their disadvantages predominate here, so that ultimately the solder joints are preferred in practice.

The object of the invention is to provide an alternative connection technology and connection device for the mechanical and electrical connection or interconnection of individual galvanic elements, which have led out of these or protruding electrode contacts to provide a multi-cell battery or a multi-cell accumulator.

This object is achieved by the connecting device for the mechanical and electrical connection of individual galvanic elements having the features of patent claim 1. Advantageous embodiments are the subject of dependent claims.

Accordingly, a connecting device for mechanical and electrical connection of galvanic elements, which have led out of these electrode contacts, wherein the connecting device has at least one printed circuit board with at least one contact surface of a contact element and a voltage against the at least one circuit board counter element and wherein the at least one circuit board and that at least one tensionable counter-element can be arranged to clamp such electrode contacts between the contact surface of the at least one printed circuit board and the counter-element which can be clamped against it.

The preferred embodiment combines the advantages of the compound by utilizing a mechanical clamping connection by means of a non-generic for galvanic elements circuit board.

The printed circuit board and the counter element connect galvanic elements via their lead out electrode contacts by clamping between them by force and form fit. The clamping has the advantage that the problems of cohesive joining methods soldering and welding of the different material pairings are avoided, and an independent of the materials of the cell or electrode contacts electrical and mechanical connection is achieved without a heat input. By using printed circuit board pairings or a printed circuit board and a counter element clamping can be done in contrast to known clamping connections with much fewer components, time-saving and significantly cheaper, since the production and reproduction of printed circuit boards in many standardized production systems is much cheaper than the Production of z. B. clamps for a particular cell type. Individually adapted for the cell package circuit boards can be produced with much less effort than the previously known Clamping fasteners. Thus, this method is technically easy to implement for both large and small and small series and also economically interesting.

A clamp connection allows a quick installation and thus a cost savings, since with a particular single clamping or clamping operation a large number of electrode contacts and different polarity can be clamped together.

Another advantage of using a clamping connection in contrast to a cohesive connection is a later solubility of the connection. This makes it possible to exchange individual defective or reduced-power cells relatively easily and quickly, instead of having to exchange and dispose of the entire cell pack, which is of interest, especially for large and expensive cell packages.

Preferably, the counter element is designed as a second, further printed circuit board, in particular a further printed circuit board with at least one further contact surface of a further contact element.

In particular, such a connection device can also be made of at least two rigid circuit boards, which are connected to at least one flexible connection to an element. In the case of such a so-called rigid-flex-PCB (PCB: Printed Circuit Board / German: printed circuit board) can be folded during assembly of two of its circuit board elements and clamp between them such electrode contacts of galvanic elements and thereby electrically contact.

Such a connection device is preferred if, in the clamped state, the at least one printed circuit board and the at least one counter element are designed to have a low enough spacing between them and configured to clamp at least one of the electrode contacts inserted therein or if the spacing laterally engages at least one of them the electrode contacts less than the at least one of the electrode contacts is configured.

However, this does not exclude that an area next to the electrode contacts with z. B. foam or fat is filled or an area in which the electrode contacts are inserted, for. B. coated with a conductive paste, z. B. to provide corrosion protection or additional stability.

In particular, the at least one printed circuit board and / or the at least one tensionable counter element preferably has at least one electrode contact through opening, which is configured as a feedthrough or through opening for carrying out at least one of the electrode contacts. Such insertion openings offer a particularly dense guidance and thus alignment of the electrode contact passed through.

On the at least one printed circuit board and / or on the counter element adjacent or opposite to the at least one electrode contact passage opening, such a contact surface can be formed. A bent portion of an electrode contact is due to the design particularly tightly clamped against a contact surface opposite him.

Particularly preferred is the contact element or are the contact elements with the at least one contact surface as a thick copper layer or at least as contactable to the surface of the circuit board and / or the counter-element executed copper inlay (German: copper insert) or as a to the surface of the circuit board and / or the counter element formed contactable executed metal core.

By using printed circuit boards with so-called thick copper layers, which have a final thickness of the electrically conductive coating of more than the standard standard thickness of 35 .mu.m, not only a high current carrying capacity for more powerful applications can be achieved, but also a secure contact by an elastic clamping force and a partially plastic Deformation of the contacting layer can be ensured.

In the clamped state of the at least one printed circuit board and the at least one counter-element, the at least one contact surface is preferably firmly clamped against at least one of the electrode contacts of a first such galvanic element inserted therein and against at least one of the electrode contacts of a second such galvanic element inserted therein so an electrical connection between the electrode contacts. In order to contact two poles of two cells, thus a common contact surface is used. This does not exclude that the other two poles or electrode contacts for external contacting of the pack are simply guided only to the outside.

Such a connecting device is advantageous with a large number of at least two such electrically separated contact surfaces and with a large number of such electrode contact through-openings, which are for performing in each case at least one of the electrode contacts are formed, wherein at least a part of the contact surfaces are arranged spatially extending such that they form a series and / or parallel connection of inter-clamped or clamped electrode contacts of various such galvanic elements.

Independently advantageous is an arrangement with such a connecting device, in which between the at least one contact surface of the at least one printed circuit board and the counter-tensioned counter electrode electrode contacts at least one such galvanic element are clamped, wherein the galvanic element is formed as a flat battery cell or as a so-called Pouch cell.

In particular, it is advantageous if in such a connecting device with at least one clamped such galvanic elements or in such an arrangement, the galvanic element or the galvanic elements are formed as lithium polymer elements.

Thus, a soldering and welding-free and optionally even circuit-forming cell connector for galvanic elements, in particular for flat cells, each provided with at least two outstanding contact elements, wherein the contact tabs or contact elements are clamped at least between two circuit boards.

The contacting circuit board coating may also be provided with further coatings, such as tinned with solder, to increase the resiliency or plastic deformability.

Possible but not absolutely necessary is an additional cohesive connection by soldering or welding the cell contacts on the contact surfaces of the printed circuit boards used.

The two electrode contacts of the cell or cells are preferably inserted through openings of an electrically insulating circuit board and placed angled on this. A second circuit board is positioned over it, so that by a clamping force that can be applied at one or more points by means of screws or spring elements, the two circuit boards clamp the cell contacts lying between them clamped.

An embodiment will be explained in more detail with reference to the drawing. Show it:

1 a side sectional view through a connecting device for the mechanical and electrical connection of galvanic elements having these led out electrode contacts and are clamped between two circuit boards,

2 a plan view of the first, lower of the printed circuit boards with inserted electrode contacts with removed upper circuit board and

3 a respective individual plan view of the two opposite sides of the second circuit board.

How out 1 can be seen, between a first and a second circuit board PCB-A, PCB-B electrode contacts L1, L2 of two or more galvanic elements Z1, Z2 placed and clamped therebetween.

By direct contact or superimposition of such electrode contacts, these can be electrically connected to each other. Preferably, one or more such printed circuit boards PCB-A, PCB-B contact elements with contact surfaces A1, A2, B, which are stretched against the electrode contacts L1, L2 and serve as electrical conductors to other electrode contacts L1, L2 and / or other electrical components ,

The preferred example thus also shows purely by way of example with reference to the further figures the connection of four lithium polymer accumulator cells as the galvanic elements Z or Z1, Z2, which are conventional bag cells with led out metal contact tabs or electrode contacts L and Z1 , Z2 are executed, to a so-called 2s2p, that is, a serial connection of two parallel pairs of a cell type, by means of two preferably equal-sized circuit boards PCB-A, PCB-B. For assembly, the galvanic elements Z are arranged aligned in the same direction in the same direction to two times two stacks.

In the example, the PCB-A, PCB-B rectangular PCBs significantly overlap the heights of the two superimposed pairs of cells to provide enough space for screw mounting. The carrier material of both printed circuit boards is made of electrically insulating material.

Preferably, one of the circuit boards has the same number of openings in the manner of the passage openings S, as electrode contacts L of the cells are present in total in order to carry out the contacts of the cells can. In the example, these z. B. eight passage openings S adapted as the contact tabs of the cells, narrow slots in PCB-A running in their width, length and position, a slight push of the contact tabs Allow cells in their arrangement with a little, but preferably not too much play.

The first printed circuit board PCB-A has on one side a total of eight designed as non-insulated thick copper layers contact surfaces A respective contact elements, which lie respectively directly on the longitudinal sides of the slots. The pushed-through cell contacts or their bent or angled electrode contact sections L *, L1 *, L2 * of the tab-shaped electrode contacts L, L1, L2 are placed on them during assembly.

The counterpart element PCB-B as the second circuit board also has such contact surfaces B, P1, M1, P, M of respective contact elements on both sides thereof. On the one hand, these are three inside contact surfaces B, P1, M1 on the side of the second printed circuit board PCB-B, which faces during the assembly of the first printed circuit board PCB-A to contact overlapping contact plates and thus to realize the circuit for 2s2p. On the other hand, these are two contact surfaces P, M on the opposite side, which faces away from the cell pack after assembly or on the outside to serve as contact surfaces P, M for the entire cell packet to a circuit. At these two contact surfaces P, M z. B. strands are soldered.

The inside contact surfaces B, P1, M1, which are later arranged facing the first printed circuit board PCB-A, summarize the poles of the cells or the corresponding electrode contacts L, L1, L2 of the galvanic elements Z together. On the one hand, the two negative poles of the first stacked cell pair are connected to each other to obtain the Gesamtminuspol as the one of the contact surfaces M1 of the cell stack by parallel connection. On the other hand, the two plus poles of the other cell pair are also combined to form the total positive pole as one of the further contact surfaces P1. The remaining, opposite polarity contact tab pairs of the cell pairs are electrically connected via a larger of the contact surfaces B by covering all four contact tabs or electrode contacts L, L1, L2.

The contact surfaces P and M for soldering strands are listed here only as an example and are not mandatory in this form. Other and further contact elements can also be used. The contact surfaces can be connected to one another by means of conventional printed circuit board elements. Thus, in this example, the two respective opposite contact surfaces P are electrically conductively connected to P1 and M to M1 by means of plated-through holes V.

The electrode contacts L, L1, L2 are pushed through the lead-through openings of the first printed circuit board PCB-A and placed flush bent on the lying next to the slots contact surfaces A of the PCB PCB-A. If necessary, the electrode contacts of the cells can also be shortened if necessary. The second printed circuit board PCB-B is now placed in particular flush over the first printed circuit board PCB-A that their three inside contact surfaces M1, B and P1 on the electrode contacts L, L1, L2 of the cells and the two opposite contact surfaces P and M after outside.

In addition, in particular assembly aids, such. As asymmetrically arranged screw holes or through holes X, marks, registration marks or unique PCB shapes, be provided which preclude a faulty assembly.

By means of a clamping force, which is applied for example by six screw through six through holes X on the edge of the rectangular circuit boards, the circuit boards are pressed against each other. For this, as in 1 sketched out by screws SC1, SC2 as the first clamping elements through corresponding through holes X and braced with nuts T1 and T2 as counter-clamping elements. Optionally, for. B. washers U1, U2 be interposed.

The angled electrode contact sections L *, L1 *, L2 * lying parallel between the printed circuit boards PCB-A, PCB-B now clamp between the contact surfaces A, B, M1, P1 of the printed circuit boards PCB-A, PCB-B, are mechanical due to frictional connection attached and have electrical contact by contact with the contact surfaces.

Due to the angled implementation of the contacts to the outer cells continue to be a particularly advantageous mechanical attachment of the cells by positive engagement.

Can be implemented a variety of variations.

Other versions of possible screw connections are z. B. also possible. Also, other ways to apply clamping forces that press the boards against each other, z. B. external additional terminals, springs or spring pins implementable.

Also, it is not mandatory that it must be two printed circuit boards PCB-A, PCB-B. Also, the use of more than two circuit boards is quite possible, so that z. B. two are clamped with one half of each size against a.

A circuit board can also be designed in so-called rigid-flex design, which is then folded. In particular, such a circuit board or such a counter element does not necessarily have to be planar. Structured surfaces can also have these.

The principle of clamping the electrode contacts can in principle be applied to any number and combination of cells as galvanic elements.

In a practical embodiment, preference is given to a variant in which both printed circuit boards have through-openings which are arranged offset from one another, so that the cell contacts are pushed through both printed circuit boards with alternating bending direction.

The printed circuit boards may have electrically conductive or insulating layers or elements which are either insulated or not insulated on the outer sides or the inner layers. B. can be designed as printed conductors, surfaces or inserts. Also, one or both of the circuit boards can accommodate more mechanical, electrical or electronic components, eg. As screws, threads, electronic semiconductor devices, resistors, fuses, switches, plugs, lights.

Optionally, one or both printed circuit boards may have electrically conductive contact surfaces that clamp into electrical contact with individual cell contact tabs. These contact surfaces can be electrically conductively connected to one another in various ways, so that the cells can be electrically connected to one another in a predeterminable arrangement of groups connected in parallel and in series.

Also, one or both printed circuit boards can have further electrical contact options, with which contacts to other devices, circuits or devices are possible.

LIST OF REFERENCE NUMBERS

• A, A1, A2

  Contact surfaces of contact elements

  B

  inside contact surface of a contact element

  d

  Distance between PCB-A and PCB-B

  L1, L2

  electrode contact

  L *, L1 *, L2 *

  angled electrode contact section

  M, M1

  Contact surfaces of contact elements as a negative pole

  P, P1

  Contact surfaces of contact elements as positive pole

  PCB-A

  circuit board

  PCB-B

  Counter element, in particular printed circuit board

  S

  Electrode contact-through opening

  SC1, SC2

  Bolt as clamping element

  T1, T2

  Nut as a counter-clamping element

  U1, U2

  washer

  V

  vias

  X

  Through holes

  Z1, Z2

  galvanic elements

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been 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.

Cited patent literature

• DE 202004015179 U1 [0012]
• WO 2007/121445 A2 [0013]

Claims (10)

Connecting device for the mechanical and electrical connection of galvanic elements (Z1, Z2), which have led out of these electrode contacts (L1, L2, L *, L1 *, L2 *), characterized by at least one printed circuit board (PCB-A) with at least one contact surface (A, A1, A2) of a contact element and against the at least one printed circuit board (PCB-A) tensionable counter element, wherein the at least one printed circuit board (PCB-A) and the at least one tensionable counter element (PCB-B) can be arranged, such electrode contacts (L1, L2, L *, L1 *, L2 *) between the contact surface (A, A1, A2) of the at least one printed circuit board (PCB-A) and on the other hand clampable counter-element (PCB-B). Connecting device according to claim 1, wherein the counter-element (PCB-B) as a further printed circuit board, in particular a further printed circuit board with at least one further contact surface (B) of a further contact element is formed. Connecting device according to claim 1 or 2, wherein in the clamped state of the at least one printed circuit board (PCB-A) and the at least one counter-element (PCB-B) a distance between them (d) Is designed to be low enough and at least one of the electrode contacts (L1, L2, L *, L1 *, L2 *) inserted therein is firmly clamped or - Is laterally at least one of the electrode contacts inserted therein (L1, L2, L *, L1 *, L2 *) less than the at least one of the electrode contacts (L1, L2, L *, L1 *, L2 *). Connecting device according to any preceding claim, wherein the at least one printed circuit board (PCB-A) and / or the at least one tensionable counter-element (PCB-B) at least one electrode contact passage opening (S) which as a feedthrough or insertion opening for performing each at least one of the electrode contacts (L1, L2, L *, L1 *, L2 *) is configured. Connecting device according to claim 4, wherein on the at least one printed circuit board (PCB-A) and / or on the counter-element (PCB-B) adjacent or opposite to the at least one electrode contact passage opening (S) such a contact surface (A) is formed. A connecting device according to any preceding claim, wherein the contact element or elements are made to be in contact with the at least one contact surface (A, B) as a thick copper layer or as surface contactable to the surface of the printed circuit board (PCB-A) and / or counter-element (PCB-B) Copper inlay (German: copper insert) or formed as a contact surface to the surface of the circuit board (PCB-A) and / or the counter-element (PCB-B) executed metal core. Connecting device according to any preceding claim, wherein in the clamped state of the at least one printed circuit board (PCB-A) and the at least one counter-element (PCB-B), the at least one contact surface (B) at least one of the electrode contacts (L1) of a first such inserted therein galvanic element (Z1) as well as at least one of the electrode contacts (L2) of a second such galvanic element (Z2) inserted therein and forms an electrical connection between the electrode contacts (L1, L2). Connecting device comprising a multiplicity of at least two such electrically separated contact surfaces (A, B) and having a multiplicity of electrode contact passage openings (S) according to Claim 4, which are used to carry out at least one of the electrode contacts (L1, L2; L *, L1 * , L2 *) are formed, wherein at least a part of the contact surfaces (A, B) are arranged so as to extend spatially in such a way that they can be connected in series and / or in parallel by clamping or clamped electrode contacts (L1, L2; L *, L1 *, L2 *) of different such galvanic elements (Z1, Z2). Arrangement with a connection device according to any preceding claim, wherein between the at least one contact surface (A; B) of the at least one printed circuit board (PCB-A) and the oppositely biased counter element (PCB-B) electrode contacts (L1, L2; L *, L1 *, L2 *) of at least one such galvanic element (Z1, Z2) are clamped, wherein the galvanic element (Z1, Z2) is designed as a flat battery cell or as a so-called Pouch cell. Connecting device according to one of claims 1 to 8 with at least one clamped such galvanic elements (Z1, Z2) or arrangement according to claim 9, wherein the galvanic element (Z1, Z2) or the galvanic elements (Z1, Z2) as lithium polymer elements are formed.

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