Set of electrochemical cells with helical electrodes and variable internal connections.

Abstract

A set of electrochemical cells (F10), each member of which has an envelope comprising at least one outer face with a negative terminal and a positive terminal arranged on it, and an inner face delimiting an internal volume in which a positive electrode is arranged, connected by a first electrical bond to the positive terminal, and a negative electrode is connected by a second electrical bond to the negative terminal. The arrangement of the positive and negative electrodes is unique and the same for all the electrochemical cells (10) in the set (F10), whereas the arrangement of the positive and negative terminals on the outer face differs from one electrochemical cell (10) to another. Figure 2

Description

Title of the invention: Set of electrochemical cells with helical electrodes and variable internal connections.

[0001] The invention relates to a set of electrochemical cells whose members share the same electrode arrangement and are differentiated by the internal connection and the arrangement of the electrical terminals. Previous art

[0002] Fig. 1 schematically illustrates the internal arrangements of electrochemical cells known from the prior art.

[0003] Electric or hybrid vehicles are equipped with electrochemical cells to power an electric motor. Each electrochemical cell comprises a casing within which a positive electrode 7 and a negative electrode 5 are arranged ([Fig. 1]). These are connected to a positive and a negative electrical terminal, respectively, both accessible from outside the casing. Four types of electrode arrangements are known to those skilled in the art: the simple layer stacking arrangement 1, the 'Z' stacking arrangement 2, the circular cylindrical winding arrangement 3, and the prismatic winding arrangement 4. The positive electrode 7 and the negative electrode 5 are always separated by an electrical separator insulator 6.

[0004] Each arrangement corresponds mainly to a type of envelope.

[0005] The simple layer stacking arrangement 1 consists of placing planar layers alternately positive electrode 7, separator 6 and negative electrode 5 and electrically connecting the positive electrode layers 7 together and the negative electrode layers 5 together.

[0006] The "Z" stacking arrangement 2 differs from the simple layer stacking only by the separator 6 which is a continuous band alternately arranged between the positive electrode 7 and negative electrode 5 layers.

[0007] In the circular cylindrical winding arrangement 3, the positive electrode 7, the negative electrode 5 and the separator 6 are all three in strips placed against each other, they are wound together around a common axis so as to form a circular cylinder.

[0008] The prismatic winding arrangement 4 differs from the circular winding 3 in that the final shape of the winding is not circular. [Fig. 1] shows an oblong prismatic winding 4, but other shapes can be chosen depending on the shape of the envelope.

[0009] In all cases the positive electrode-positive electrical terminal and negative electrode-negative electrical terminal connections are short and the internal arrangement of the electrodes 7, 5 conditions the positioning of the electrical terminals outside the envelope or the application for which the electrochemical cell is intended imposes the positioning of the electrical terminals which in turn imposes a type of electrode arrangement. Summary of the invention

[0010] The invention presented here solves this problem by allowing the internal arrangement of the electrodes and the external arrangement of the electrical terminals to be separated, and thus giving designers all the necessary freedom in the positioning of said electrical terminals.

[0011] In particular, the invention relates to an assembly of electrochemical cells, each electrochemical cell in the assembly being provided with an envelope comprising an inner face and an outer face on which are arranged a positive electrical terminal and a negative electrical terminal. The inner face delimits an internal volume in which are arranged a positive electrode connected by a first electrical connection to the positive electrical terminal and a negative electrode connected by a second electrical connection to the negative electrical terminal.

[0012] Advantageously the arrangement of the electrodes is unique and the same for all the electrochemical cells in the set, whereas the arrangement of the positive electrical terminal and the negative electrical terminal on the outer face differs from one electrochemical cell to another.

[0013] The envelope of each electrochemical cell, member of the set of electrochemical cells, extends along a longitudinal axis, the envelope comprising a cylindrical wall closed at its two longitudinal ends by two end walls: a first end wall arranged at a first end and, a second end wall arranged at a second opposite end.

[0014] Advantageously, the electrodes together form a double helix extending along the longitudinal axis, each electrode having a first end edge adjacent to the first end wall and a second end edge adjacent to the second end wall, the end edges being connected by an inner edge adjacent to the longitudinal axis and an outer edge adjacent to the cylindrical wall.

[0015] The invention also relates to the electrochemical cells that are members of the set of electrochemical cells presented above.

[0016] An electrochemical cell member of the set of electrochemical cells has at least one of the electrical bonds extending from one of the end edges of one of the electrodes to the corresponding electrical terminal, said electrical terminal being located on one of the end walls.

[0017] An electrochemical cell member of the set of electrochemical cells has at least one of the electrical bonds extending from the outer edge of one of the electrodes to the corresponding electrical terminal, said terminal being located on the cylindrical wall.

[0018] An electrochemical cell member of the set of electrochemical cells has at least one of the electrical bonds extending from the inner edge of one of the electrodes to the corresponding electrical terminal, said electrical terminal being located on one of the end walls.

[0019] The invention also relates to an electric or hybrid vehicle comprising at least one electrochemical cell member of the set of electrochemical cells presented above. Brief description of the figures

[0020] The invention will be further detailed by the description of non-limiting embodiments and, on the basis of the attached figures. - [Fig.1] schematically illustrates the internal arrangements of electrochemical cells known from the prior art. - [Fig.2] schematically illustrates a set of electrochemical cells according to the invention and several of its members. - [Fig.3] schematically illustrates a first electrochemical cell of the whole of [Fig.2]. - [Fig.4] schematically illustrates a second electrochemical cell of the whole of [Fig.2]. - [Fig.5] schematically illustrates a third electrochemical cell of the whole of [Fig.2]. - [Fig.6] schematically illustrates a fourth electrochemical cell of the whole of [Fig.2]. - [Fig.7] schematically illustrates a variant of the fourth electrochemical cell of [Fig.6]. - [Fig.8] schematically illustrates a fifth electrochemical cell of the whole of [Fig.2].

[0021] Embodiment

[0022] Fig. 2 represents some electrochemical cells 10, all members of the same set F10 of electrochemical cells.

[0023] All the electrochemical cells 10 of the F10 assembly share common characteristics listed below and more easily observable in figures 2 and following.

[0024] The electrochemical cells 10 have a cylindrical envelope 20 which extends along a longitudinal axis L, the envelope 20 having an outer face 30 and an inner face 35. More particularly the envelope 20 comprises a cylindrical wall 110 closed at its opposite longitudinal ends by two end walls: a first end wall 120 and a second end wall 130.

[0025] For the sake of simplification, the cylindrical envelope 20 represented here has a circular cross-section, but the invention applies identically to electrochemical cells 10 having cylindrical envelopes 20 with an oblong, polygonal or other cross-section.

[0026] Whatever its shape, the envelope 20 defines an internal volume VI in which two electrodes are arranged, a positive electrode 60 and a negative electrode 80, separated from each other by an electrical separator, represented only in [Fig.1].

[0027] From the point of view of their shape, the two electrodes 60, 80 are identical: each is wound in a helix and forms a helicoid wound along the longitudinal axis L. These helicoids are wound together so that each electrode extends throughout the entire internal volume VI, from one longitudinal end to the other. The electrodes 60, 80 are always electrically separated from each other by the separator.

[0028] The helicoid of the positive electrode 60 comprises four sides: a first end edge 61 adjacent without electrical contact of the first end wall 120 of the envelope, a second end edge 62 adjacent without electrical contact of the second end wall 130 of the envelope, an inner edge 63 adjacent without electrical contact of the longitudinal axis L and an outer edge 64 adjacent without electrical contact of the inner face 35 of the cylindrical wall 110 of the envelope.

[0029] Similarly, the helicoid of the negative electrode 80 comprises four sides: a first end edge 81 adjacent without electrical contact of the first end wall 120 of the envelope, a second end edge 82 adjacent without electrical contact of the second end wall 130 of the envelope, an inner edge 83 adjacent without electrical contact of the longitudinal axis L and an outer edge 84 adjacent without electrical contact of the inner face 35 of the cylindrical wall 110 of the envelope.

[0030] The inner edges 63 and outer edges 64 of the positive electrode and the inner edges 83 and outer edges 84 of the negative electrode are helices wound around the longitudinal axis, these edges extending from one end edge 61, 81 to the other 62, 82 of their respective electrode.

[0031] The electrochemical cells 10 are also provided with two electrical terminals, each being electrically connected to an electrode by an internal connection in the casing 20. Thus, a positive electrical terminal 40 is connected to the positive electrode 60 by a first electrical connection 70 and, a negative electrical terminal 50 is connected to the negative electrode 80 by a second electrical connection 90. While all the electrochemical cells 10 of the assembly F10 share the same arrangement of the electrodes 60, 80 in a double helix, the electrochemical cells are distinguished from one another by the shape and positioning on the outer face 30 of the casing 20 of the positive electrical terminals 40 and negative electrical terminals 50.

[0032] Advantageously, the helical arrangement of the electrodes described above allows each electrode to be in close proximity to the entire surface of the casing walls. Thus, the electrical terminals 40, 50 can be placed anywhere on the outer face 30 of the casing while keeping the internal connections of the two electrical links 70, 90 short.

[0033] Figures 3 to 8 represent more particularly some examples of electrochemical cells 10 of the F10 assembly, all benefiting from the common characteristics of electrode arrangement 60, 80. They are distinguished by the positioning and shape of the positive 40 and negative 50 electrical terminals.

[0034] Figure 3 represents a first electrochemical cell 10 of the assembly F10 of electrochemical cells in which the positive electrical terminal 40 is located on the first end wall 120 and the negative electrical terminal 50 is, on the opposite side, on the second end wall 130 of the casing. The first electrical bond 70 extends from the second end edge 62 of the positive electrode 60 to the positive electrical terminal 40, and the second electrical bond 90 extends from the first end edge 81 of the negative electrode 80 to the negative electrical terminal 50.

[0035] The electrical connections 70, 90, here schematically represented by simple lines, can have different forms, including welded links, tabs extending from their electrode, or others.

[0036] Similarly, the circular schematic electrical terminals 40, 50 can also have other shapes chosen in particular according to the intended use.

[0037] Figure 4 represents a second electrochemical cell 10 of the assembly F10 of electrochemical cells in which the positive electrical terminals 40 and 50 are both located on the same end wall 120, 130. In Figure 4, the first end wall 120 of the casing has been chosen; therefore, the first electrical bond 70 extends between the second end edge 62 of the positive electrode 60 and the positive electrical terminal 40, and the second electrical bond 90 extends, for its part, between the second end edge 82 of the negative electrode 80 and the negative electrical terminal 50.

[0038] The symmetrical situation similar to [Fig.4] in which the two terminals 40, 50 are arranged opposite each other on the second end wall 130 is not shown.

[0039] Figure 5 represents a third electrochemical cell 10 of the F10 assembly of electrochemical cells in which the positive electrical terminal 40 is located on the first end wall 120 of the casing, and the negative electrical terminal 50 forms a band that surrounds the cylindrical wall 110 of the casing. The first electrical bond 70 extends between the second end edge 62 of the positive electrode 60 and the positive electrical terminal 40, and the second electrical bond 90 extends from the outer edge 84 of the negative electrode 80 to the negative electrical terminal 50, forming a band.

[0040] The symmetrical situation similar to [Fig.5] in which the terminals would be reversed, the positive terminal 40 forming an outer band and the negative terminal 50 a button on one end of the envelope is not shown.

[0041] Advantageously, thanks to the helical arrangement of the electrodes whose outer edges 64, 84 are adjacent without electrical contact of the entire inner face of the cylindrical part 110 of the casing, the outer strip-shaped terminal can be placed anywhere on the outer face of the casing, closer to one end or closer to the other.

[0042] A variant of the electrochemical cell 10 of [Fig. 5] consists of a cell in which one of the two electrical terminals is located on the outer cylindrical face. The internal connection of this terminal is a connection to the outer edge of one of the electrodes. The other electrical terminal is on an end face and its connection is a connection to the inner edge of the other electrode.

[0043] Since the size and shape of the electrical terminals are not determined, in this embodiment, the terminals can occupy the entire surface of the face on which they are placed. Thus, the entire outer cylindrical face is one of the terminals, and one of the end faces is also entirely a terminal.

[0044] Figure 6 represents a fourth electrochemical cell 10 of the assembly F10 of electrochemical cells in which the positive 40 and negative 50 electrical terminals form two bands surrounding the cylindrical wall 110 of the casing. The first electrical bond 70 extends from the outer edge 64 of the positive electrode 60 to the positive electrical terminal 40, and the second electrical bond 90 extends from the outer edge 84 of the negative electrode 80 to the negative electrical terminal 50.

[0045] Figure 7 represents an alternative to the fourth electrochemical cell of Figure 6. The electrical terminals 40, 50 are here in the form of buttons rather than strips. This alternative illustrates the fact that the terminals can have any The shape, where the bands may not completely encircle the envelope but only a limited sector of its circumference. Also, the bands may be more or less wide, and furthermore, they may themselves have a helical shape.

[0046] Fig. 8 illustrates a fifth electrochemical cell 10, member of the set F10 of electrochemical cells, in which the electrical terminals 40, 50 are located at both ends of the envelope 20, the first electrical bond 70 extending from the inner edge 63 of the positive electrode 60 to the positive electrical terminal 40 and, the second electrical bond 90 extending from the inner edge 83 of the negative electrode 80 to the negative electrical terminal 50.

[0047] An unrepresented variant consists of an electrochemical cell 10, a member of the F10 set of electrochemical cells, in which one of the electrical terminals 40, 50 is located on an end wall 120, 130 of the envelope 20, the corresponding electrical connection 70, 90 extending from the inner edge 63, 83 of one of the electrodes 60, 80 to said electrical terminal 40, 50 and, the other electrical terminal has its electrical connection extending from the outer edge, or an end edge, of the other electrode.

[0048] Only a few variants are represented, the designer being able to choose independently of the arrangement of the electrodes 60, 80 the locations and shapes of the electrical terminals 40, 50, while maintaining each time short electrical links 70, 90 between the electrodes 60, 80 and the electrical terminals 40, 50.

[0049] References used

[0050] 1 prior art - stacking in simple layers

[0051] 2 prior art - "Z" stacking

[0052] 3 anterior art - circular winding

[0053] 4 anterior art - prismatic winding

[0054] 5 anterior artery - positive electrode

[0055] 6 anterior artery - negative electrode

[0056] 7 prior art - electrical separator

[0057] F10 Electrochemical cell assembly

[0058] 10 electrochemical cell

[0059] VI internal volume

[0060] The longitudinal axis

[0061] 20 envelopes

[0062] 30 outer face

[0063] 35 inner face

[0064] 40 positive electrical terminal

[0065] 50 negative electrical terminal

[0066] 60 positive helical electrode

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[0080] 61 first end edge of the positive electrode 62 second end edge of the positive electrode 63 inner edge of the positive electrode 64 outer edge of the positive electrode 70 first electrical bond, positive electrode-positive terminal 80 helical negative electrode 81 first end edge of the negative electrode 82 second end edge of the negative electrode 83 inner edge of the negative electrode 84 outer edge of the negative electrode 90 second electrical bond, negative electrode-negative terminal 110 cylindrical wall 120 first end wall 130 second end wall

Claims

1. Demands Electrochemical cells (10) provided with an envelope (20) extending along a longitudinal axis (L), the envelope (20) comprising a cylindrical wall (110) closed at its two longitudinal ends by two end walls, a first end wall (120) arranged at one end and a second end wall (130) arranged at a second opposite end, this envelope comprising an inner face (35) and an outer face (30) on which are arranged a positive electrical terminal (40) and a negative electrical terminal (50), the inner face (35) delimiting an internal volume (VI) in which are arranged a positive electrode (60) connected by a first electrical connection (70) to the positive electrical terminal (40) and a negative electrode (80) connected by a second electrical connection (90) to the negative electrical terminal (50), the electrodes (60, 80) together forming a double helix extending along the longitudinal axis (L), each electrode (60,80) having a first end edge (61, 81) adjacent without electrical contact to the first end wall (120) and a second end edge (62, 82) adjacent without electrical contact to the second end wall (130), the end edges (61, 81, 62, 82) being connected by an inner edge (63, 83) adjacent without electrical contact to the longitudinal axis (L) and an outer edge (64, 84) adjacent without electrical contact to the cylindrical wall (110), characterized in that, -at least one of the electrical connections (70, 90) extends from the outer edge (64, 84) of one of the electrodes to the corresponding electrical terminal (40, 50), said terminal being located on the cylindrical wall (110), Or -at least one of the electrical connections (70, 90) extends from the inner edge (63, 83) of one of the electrodes (60, 80) to the corresponding electrical terminal (40, 50), said electrical terminal being located on one of the end walls (120, 130), Or -one of the electrical connections (70, 90) extends from one of the end edges (61, 81, 62, 82) or from the inner edge (63, 83) of one of the electrodes up to the corresponding electrical terminal, said terminal being located on one of the end walls (120, 130), the other electrical connection 70, 90) extending from one of the end edges (61, 81, 62, 82) or from the inner edge (63, 83) of the other electrode up to the corresponding electrical terminal, said terminal being located on the other end wall (120, 130).

2. Electrochemical cell (10) according to claim 1, characterized in that the terminal located on the cylindrical wall (110) is in the form of an outer strip.

3. Electric or hybrid vehicle comprising at least one electrochemical cell (10) according to any one of claims 1 or 2.

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