A LAMINATE, A BATTERY AND A METHOD

Abstract

A laminate for a battery and a battery with the laminate, where the anode and/or cathode layer is a single layer where anode or cathode material particles are interconnected by an electrically conducting element.

Claims

1.-20. (canceled)

21. A laminate for use in a battery, the laminate comprising: a first electrode layer, a second electrode layer and a separator provided between the first electrode layer and the second electrode layer, wherein at least one of the first and second electrode layer comprises particles of a predetermined material and an electrically conducting material interconnecting the particles.

22. The laminate according to claim 21, wherein the electrode material is an anode material and the electrically conducting material comprises cupper, tin, antimony, silicon or alloys comprising such materials.

23. The laminate according to claim 21, wherein the electrode material is a cathode material and wherein the electrically conducting material comprises aluminium, lithium, nickel or magnesium or alloys comprising one or more thereof.

24. The laminate according to claim 21, wherein the electrically conducting material comprises between 2 and 40 percent, by volume, of the electrode material.

25. A battery comprising a laminate according to claim 21, the laminate being provided in a casing having a first and a second terminal, the first terminal being connected to the first electrode layer and the second terminal being connected to the second electrode layer.

26. A method of manufacturing a laminate for a battery, the method comprising: providing particles of a solid electrode material, providing an amount of a predetermined electrically conducting material, having the electrically conducting material interconnect the particles to form a first electrode layer, providing a laminate with the first electrode layer, a second electrode layer and a separator provided between the first electrode layer and the second electrode layer.

27. The method according to claim 26, wherein the step of providing the electrically conducting material comprises providing fibres of the electrically conducting material, and wherein the interconnecting step comprises providing the fibres as woven structure and providing the particles therein or thereon.

28. The method according to claim 26, wherein the step of providing the electrically conducting material comprises providing fibres of the electrically conducting material, and wherein the interconnecting step comprises providing the fibres as non-woven structure and providing the particles therein or thereon.

29. The method according to claim 26 wherein the interconnecting step comprises heating the particles and electrically conducting material to have the electrically conducting material act as a binder binding the solid material after cooling.

30. The method according to claim 26, wherein the interconnecting step comprises compressing the electrically conducting material and the particles to have the electrically conducting material act as a binder binding the powder.

31. The method according to claim 26, further comprising a step, between the interconnecting step and the lamination step, of providing a surface porosity in the layer.

32. The method according to claim 31, wherein the step of providing the surface porosity comprises feeding the layer over a roller comprising a number of spikes.

33. The method according to claim 26 comprising the step of, subsequent to the shaping step, of rolling the layer on to a roll, and wherein the lamination step comprises feeding the layer from the roll.

34. The method according to claim 26, wherein the step of providing the particles and the electrically conducting material comprises providing, as the particles, an anode material and, as the electrically conducting material, cupper, tin, antimony, silicon or an alloy comprising at least one thereof.

35. The method according to claim 34, wherein the step of providing the electrically conducting material comprises providing between 10 and 40 percent, by volume, of the anode material.

36. The method according to claim 26, wherein the step of providing the particles comprises providing a cathode material and wherein the step of providing the electrically conducting material comprises providing aluminium, nickel or magnesium or alloys comprising one or more thereof.

37. The method according to claim 36, wherein the step of providing the electrically conducting material comprises providing between 10 and 40 percent, by volume, of the cathode material.

38. The method of manufacturing a battery, the method comprising providing a laminate according to a laminate for use in a battery, the laminate comprising: a first electrode layer, a second electrode layer and a separator provided between the first electrode layer and the second electrode layer, wherein at least one of the first and second electrode layer comprises particles of a predetermined material and an electrically conducting material interconnecting the particles; or manufactured according to claim 26, providing a casing and providing the laminate inside the casing as well as providing a first and a second terminal of the casing, connecting the first electrode layer to the first terminal and the second electrode layer to the second terminal.

39. The method according to claim 38, wherein the step of providing the laminate in the casing comprises folding the laminate before introduction into the casing.

40. The method according to claim 38, wherein the step of providing the laminate comprises folding the laminate before rolling the laminate.

Description

[0114] In the following, preferred embodiments of the invention will be described with reference to the drawings, wherein:

[0115] FIG. 1 illustrates a laminate for use in a battery,

[0116] FIG. 2 illustrates the laminate from the side,

[0117] FIG. 3 illustrates a layer with fibres,

[0118] FIG. 4 illustrates a cross section of a first embodiment of a laminate,

[0119] FIG. 5 illustrates a cross section of a second embodiment of a laminate, and

[0120] FIG. 6 illustrates a calendaring process.

[0121] In FIG. 1, illustrates a laminate 10 for use in a battery, the laminate comprising an anode layer 12, a separator 14 and a cathode layer 16. Preferably, the anode layer is larger than the cathode layer and the separator, which is provided between the anode and cathode, is also larger than the cathode layer. The separator may extend beyond the anode layer in at least one direction and the anode layer preferably extends beyond the separator in at least two opposed directions. The cathode preferably, in this top view when projected on to a plane, is positioned within the outer boundaries of both the anode and the separator.

[0122] A tab 18 is provided for connecting to the cathode. A similar tab may be used for the anode.

[0123] The layers and the tab are illustrated in FIG. 2 from the side.

[0124] This laminate may be rolled as is usual, or folded, and be provided in a battery casing. The electrically conducting material provided inside the layer will act to make the layer stronger so as to not break during folding or rolling.

[0125] The laminate may be folded, such as around the axis A, to provided a laminate with the anode layer exposed and with the cathode layer completely provided within the separator which now forms an enclosure for the cathode. This folded assembly is easily cased as the only layer exposed at the lower end and sides is the anode. At the top end, the separator extends out of the roll together with the tab(s). Preferably the tab has a non-conducting surface at least a portion of the distance from the cathode layer to the end the outermost portion may be electrically conducting in order to cater for electrical contacting to the cathode layer. The anode layer may be contacted anywhere on the outer surface. A structure of this type may be seen in the Applicant's co-pending application filed on even date and with the title “A CASING, BATTERY, A METHOD OF MANUFACTURING A BATTERY AND METHODS OF OPERATING THE BATTERY”.

[0126] Usually, as is described in the beginning, the anode layer and cathode layer would themselves be laminates of the actual anode or cathode layer, respectfully, and a current collector layer actually carrying the current from/to the layers. Usually, the anode is larger than the cathode and the separator is larger than the anode.

[0127] According to the invention, such anode or cathode laminates are replaced by a single anode/cathode layer having therein both the anode/cathode material as well as an electrically conducting material. This has the advantage that only a single layer need be handled.

[0128] A layer of this type may be seen in FIG. 3, wherein fibres of the electrically conducting material form a non-woven structure within the layer. Alternatively, fibres may form a woven structure in the layer, or powder/flakes may be added which also will be distributed inside the layer.

[0129] Yet another manner would be to sputter the conducting material on to the particles, or use any other manner of forming a layer of the conductor on the particles. The mix may then be heated/pressed. It may be desired to actually mix the particles subsequent to the sputtering (or other process such as plasma arch deposition) in order to randomly direct the portions of the particles having received the conducting material, before activating the conducting material by e.g. heating or pressure.

[0130] It is noted that it is possible to control the 3D aspects of optimized electrodes. In conjunction with oblique angle deposition of either Plasma Arch Metal Spray (PAMS) or sputtering and 3D texturing of the outer surface it is feasible to create a freestanding electrode where the current collector functionality also is applied in the process and have openings for electrolyte filling and exchange. Sputtering and PAMS combined with laser fusing can create an unbreakable current collector layer that may only be sub micron thick

[0131] The electrically conducting material may be mixed with the electrode material and subsequently heated and/or pressed in order to act as a binder binding the electrode material. Then, the electrically conducting material will be able to replace at least part of the binder historically used in electrode layers. Naturally, the particles and conducting material may alternatively be pre-heated before mixing and layer formation where a last heating or compression is provided to arrive at the desired temperature.

[0132] As described above, any type of heating may be used, such as using radiation heat, lasers, radiation, an oven, heated rollers or the like. A combination may even be used where the particles and conducting material may be pre-heated either individually or when mixed, where a last heating step may be carried out to arrive at the desired temperature.

[0133] Nevertheless, the electrically conducting material has the additional function of transporting charge created in the anode and cathode layers from the standard transport of ions there between to the terminals of a battery, for example. This is the historic function of the separate current collector layers of historic batteries.

[0134] Naturally, any heating may be achieved by a heated roller or rollers. Alternatively, radiation heating may be used. It may be desired that any heating takes place in an inert atmosphere or in vacuum.

[0135] Pressure may be achieved between rollers.

[0136] In addition, the layers may be made both flexible and durable to be truly free standing. Thus, roll-to-roll processing is possible which has a number of advantages. In this respect, free standing will mean that the layer is able to support its own weight even when travelling between rollers 10 cm apart.

[0137] Even though no additional binder is required, it may be desired to increase the porosity of the layer. This may be obtained in a number of manners, one being calendaring. In FIG. 6, a calendaring is illustrated where a layer 15 (anode or cathode) is rolled from one roller 151 between two calendaring rolls 153 and 154 one of which comprises small spikes and the other corresponding indentations, and finally rolled onto another roller 152. The operation of the calendaring rollers 153/4 is to force the spikes into the layer 15 in order to provide indentations or channels therein. These indentations or channels provide a larger surface and a larger porosity for the ions to use during operation of the laminate.

[0138] It is noted that naturally, the anode layer and/or cathode layer may be provided as multiple layers. Different layers may have the same constituents but different parameters. A base layer may have a higher hardness and a higher density, such as by having a higher content of the conducting material, whereas an outer layer may have a lower density to cater for a higher surface porosity. The layers may be produced individually and assembled such as by activating the conducting material in the interface between the layers.

[0139] It may be desired to provide one or more of these layers with an un-even surface in order to facilitate attachment thereto of another layer.