3D structure embossing electrode

Abstract

The present invention is directed to a secondary battery comprising one or more electrode(s) comprising a current collector material located adjacent at least one active electrode material; wherein at least one side of the one or more negative and / or positive electrode(s) has a surface roughness characterized by: (i) Ra: 0.005 μm < x < 15 μm; (ii) Rz: 0.1 μm < x < 25 μm; (iii) Rmax: 0.1 < x < 25 μm; and / or (iv) Sa: 0.005 μm < x < 15 μm; (v) Sz: 0.1 μm < x < 25 μm; (vi) Smax: 0.1 < x < 25 μm.

Description

[0001] MATTHEWS INTERNATIONAL GMBH, GutenbergstraBe 1-3, 48691 Vreden, Germany

[0002] MATTHEWS INTERNATIONAL CORPORATION Two NorthShore Center 15212 Pittsburgh, USA

[0003] 3D Structure Embossing Electrode

[0004] The present invention relates to a secondary battery comprising electrodes that have a structure embossed thereon, in particular a 3D structure. The invention also relates to a method for manufacturing such an electrode and an electrode prepared by such a method.

[0005] In recent years, the production of energy via fossil fuels is seen more and more critical and the demand for eco-friendly alternative energy sources is increasing rapidly. Eco-friendly energy sources thus have become an indispensable factor for future life. To utilize such eco-friendly energy sources most efficiently it is necessary to use power storage devices such as batteries to overcome difficulties due to the uneven availability of these forms of energy.

[0006] Possible power storage devices are secondary batteries. Secondary batteries are batteries that can be recharged (unlike primary batteries that cannot be recharged) and are already widely used in electronic devices such as mobile phones, laptop computers, camcorders, and electric vehicles. Because of this and their high energy density per unit weight, their utilization is rapidly increasing.

[0007] In the manufacturing process of secondary batteries, a first electrode material (e.g., an anode or cathode material) is produced, calendared to the required target thickness, and laminated onto a current collector. A separator and a second electrode prepared by the same or a different method is then applied, wherein the order of the process steps may vary. Once all components have been joined, a battery stack is woundup or stacked in layers and packed in a corresponding housing or bag / cell. The secondary battery can be a dry (cell) battery, a supercapacitor, a hydrofluorocarbon battery, a wet (cell) battery, or the like. In these systems, a liquid electrolyte is introduced into the battery housing / cell in order for it to function. This is usually done by injecting (forming) it into the battery housing / cell.

[0008] NAI-5008118396vl 1 Calendering smoothes and compacts the surface of the electrode, i.e., the surface of the active electrode material, wherein as a result the layers lie very close together during winding. Due to the winding process, it takes some time for the electrolyte to be evenly distributed throughout the cell and to be absorbed by the electrodes (maturation), such as days or even weeks.

[0009] It is an object of the present invention to provide a secondary battery for which the forming and maturation time is significantly shortened. The solution to this problem is provided with the features of the independent claims. Advantageous embodiments are described in the dependent claims.

[0010] According to an aspect the present invention is directed to a secondary battery comprising

[0011] • one or more electrode(s) comprising a current collector material located adjacent to at least one active electrode material; wherein at least one side of the one or more electrode(s) has a surface roughness characterized by:

[0012] (i) Ra: 0.005 pm < x < 15 pm;

[0013] (ii) Rz: 0.1 pm < x < 25 pm;

[0014] (iii) RmaX: 0.1 < x < 25 pm; and / or

[0015] (iv) Sa: 0.005 pm < x < 15 pm;

[0016] (v) Sz: 0.1 pm < x < 25 pm;

[0017] (vi) SmaX: 0.1 < x < 25 pm.

[0018] Due to the surface roughness of one or more of the electrode(s) the distribution time of an electrolyte upon injection is significantly decreased. The electrolyte can more easily move between the spaces of the current collector material, active electrode material (and separator) and is much faster absorbed by the respective materials. Wettability is generally increased. Thus, in a preferred embodiment the secondary battery comprises an electrolyte. The electrolyte can be any electrolyte suitable for the electrodes used in the secondary battery. Such electrolytes are known to skilled person.

[0019] NAI-5008118396vl - 2 - Surface roughness is a component of a surface finish, and it is quantified by the deviations in the direction of the normal vector of a real surface from its ideal form. The roughness of the inventive electrodes is defined by

[0020] (i) Ra: 0.005 pm < x < 15 pm;

[0021] (ii) Rz: 0.1 pm < x < 25 pm;

[0022] (iii) RmaX: 0.1 < x < 25 pm; and / or

[0023] (iv) Sa: 0.005 pm < x < 15 pm;

[0024] (v) Sz: 0.1 pm < x < 25 pm;

[0025] (vi) SmaX: 0.1 < x < 25 pm.

[0026] Ra (average roughness) provides a general measure of the height of the texture across a surface. Ra is the average of how far each point on the surface deviates in height from the mean height. Ra measures the deviation of a surface from a mean height.

[0027] Rz is the absolute peak to valley average of five sequential sampling lengths within the measuring length, i.e., is the average difference between the five highest peaks and the five deepest valleys of a surface’s texture.

[0028] Rmax is maximum peak-valley in the measurement.

[0029] Sa is the areal (3D) equivalent of two-dimensional Ra. Sa is the “areal average roughness,” the average height of all measured points in the areal measurement. The “S” parameters refer to measurements of a “surface,” as opposed to the “R” parameters which are calculated from the roughness profile.

[0030] Sz is defined as the sum of the largest peak height value and the largest pit depth value within the defined area.

[0031] Smax is largest peak height value and the largest pit depth value in the whole measurement area.

[0032] In one embodiment, the roughness is characterized by:

[0033] (i) R : 0.005 pm < x < 13 pm

[0034] (ii) Rz: 0.5 pm < x < 25 pm

[0035] NAI-5008118396vl T (iii) RmaX: 1 < x < 25 gm; and / or

[0036] (iv) Sa: 0.005 m < x < 13 pm;

[0037] (v) Sz: 0.5 pm < x < 25 pm;

[0038] (vi) S max^ 1 < X < 25 pm.

[0039] In another embodiment, the roughness is characterized by:

[0040] (i) Ra: 0.05 pm < x < 5 pm

[0041] (ii) Rz: 0.5 pm < x < 15 pm

[0042] (iii) RmaX: 1 < x < 25 pm; and / or

[0043] (iv) Sa: 0.05 pm < x < 5 pm;

[0044] (v) Sz: 0.5 pm < x < 15 pm;

[0045] (vi) S max^ 1 < X < 25 pm.

[0046] In another embodiment, the roughness is characterized by:

[0047] (i) Ra: 0.05 pm < x < 3 pm

[0048] (ii) Rz: 0.5 pm < x < 10 pm

[0049] (iii) RmaX: 1 < x < 25 pm; and / or

[0050] (iv) Sa: 0.05 pm < x < 3 pm;

[0051] (v) Sz: 0.5 pm < x < 10 pm;

[0052] (vi) S max^ 1 < X < 25 pm.

[0053] This unique combination of roughness parameters provides a surface that is capable of increasing the speed of the electrolyte distribution with the battery housing or battery cell.

[0054] In one preferred embodiment, the surface roughness is a non-periodical surface roughness. Non-periodical means that the peak height (and valley depth) is not distributed evenly but randomly so that no continuous pattern is present. The non-periodicity of the surface roughness acts as a multiplier for the time with which forming and maturation occurs.

[0055] In one embodiment the surface roughness is characterized by a periodic pattern.

[0056] NAI-5008118396vl - 4 - According to the invention, at least one active electrode material is located on one side of the current collector material. In a preferred embodiment, the active electrode material is located on both sides of the current collector material. In such an embodiment, the current collector material is thus located between at least two active electrode materials.

[0057] The current collector material may be selected from any suitable material known to the skilled person in the technical field encompassing the invention. Depending on its function, the current collector material may be an anode current collector material or a cathode current collector material. The current collector material has two sides (or surfaces) opposite to each other which serve as the basis for the application of the one or more active electrode material(s).

[0058] In one embodiment, at least one first active electrode material is located on a first side of the current collector material and least one second active electrode material is located on second side of the current collector material. The latter may optionally face away from the first side of the current collector material.

[0059] The active electrode material may be selected from a negative active electrode material or a positive electrode material. For example, the first active electrode material and the second active electrode material comprise one or more negative active electrode materials. In one embodiment, the first active electrode material and the second active electrode material comprise one or more positive active electrode materials. In one embodiment, the first active electrode material comprises a negative active electrode material and the second active electrode material comprises a positive active electrode material.

[0060] In a preferred embodiment, an electrode comprising an anode current collector material located between a negative electrode material is alternating in the secondary battery with an electrode comprising a cathode current collector material located between a positive active electrode material. In such an embodiment, a separator is present between the one or more negative electrode(s) and the one of the one or more positive electrode(s).

[0061] Thus, in one embodiment a secondary battery according to the invention comprises

[0062] • one or more negative electrode(s) comprising an anode current collector material located between a negative active electrode material; or

[0063] NAI-5008118396vl - 5 - • one or more positive electrode(s) comprising a cathode current collector material located between a positive active electrode material; and

[0064] • a separator located between each of the one or more negative electrode(s) and each of the one or more positive electrode(s); wherein at least one side of the one or more negative and / or positive electrode(s) has a surface roughness characterized by:

[0065] Ra: 0.005 pm < x < 15 pm;

[0066] Rz: 0.1 pm < x < 25 pm;

[0067] RmaX: 0.1 < x < 25 pm; and / or

[0068] Sa: 0.005 pm < x < 15 pm;

[0069] Sz: 0.1 pm < x < 25 pm;

[0070] Smax: 0.1 < x < 25 pm.

[0071] Any of the above-mentioned roughness characteristics also apply to the aforementioned embodiment.

[0072] According to the present invention, it may be sufficient to achieve the desired effect in case only one surface of an electrode (i.e., the surface of an active electrode material) comprises a surface roughness as provided herein.

[0073] For example, in one embodiment, a negative active electrode material is located on both sides of an anode current collector material and the surface roughness is present on (only) one surface of the negative active electrode material being distanced from and / or not in contact with the anode current collector material. This means that, for example, for a negative electrode having a layer stack of negative active electrode material- current collector material negative active electrode material, the surface of one negative electrode material is comprising the inventive surface roughness while the surface of the other negative electrode material has a “normal”, smooth surface obtained via a normal calendaring process.

[0074] It is noted that in the above and all other embodiments the surface of the active electrode material means the surface that is opposite the respective current collector material, i.e., the

[0075] NAI-5008118396vl - 6 - surface not in direct contact with the current collector material / being distanced from the current collector material.

[0076] In another embodiment, a negative active electrode material is located on both sides of an anode current collector material and the surface roughness is present on both surfaces of the negative active electrode material being distanced from and / or not in contact with the anode current collector material.

[0077] In another embodiment, a positive active electrode material is located on both sides of a cathode current collector material and the surface roughness is present on one surface of the positive active electrode material being distanced from and / or not in contact with the cathode current collector material.

[0078] In another embodiment, a positive active electrode material is located on both sides of a cathode current collector material and the surface roughness is present on both surfaces of the positive active electrode material being distanced from and / or not in contact with the cathode current collector material.

[0079] In another embodiment, the surface roughness is present on both surfaces of a negative and positive active electrode material being distanced from and / or not in contact with the anode and cathode current collector material.

[0080] In another embodiment, the surface roughness is present on all surfaces of a negative and positive active electrode material being distanced from and / or not in contact with the anode and cathode current collector material.

[0081] In another embodiment, a negative active electrode material is located on the first side of a current collector material and a positive active electrode material is located on the second side of the current collector material and the surface roughness is present on the surface of either the negative active electrode material or positive active electrode material being distanced from and / or not in contact with the current collector material.

[0082] In another embodiment, a negative active electrode material is located on the first side of a current collector material and a positive active electrode material is located on the second side

[0083] NAI-5008118396vl - 7 - of the current collector material and the surface roughness is present on both the surface of the negative active electrode material and the positive active electrode material being distanced from and / or not in contact with the current collector material.

[0084] In a still further embodiment, a negative active electrode material is located on the first side of a current collector material and the surface roughness is present on the surface of the negative active electrode material being distanced from and / or not in contact with the current collector material.

[0085] In a still further embodiment, a positive active electrode material is located on the first side of a current collector material and the surface roughness is present on the surface of the positive active electrode material being distanced from and / or not in contact with the current collector material.

[0086] In one embodiment, two or more surfaces of the negative and / or positive active electrode material have an inventive surface roughness, wherein the surface roughness is characterized by the same roughness values / characteristics. In another embodiment, two or more surfaces of the negative and / or positive active electrode material have an inventive surface roughness, wherein each surface roughness is characterized by different roughness values / characteristics.

[0087] In another aspect, the present invention is directed to a method for manufacturing an electrode for a secondary battery, the method comprises embossing the electrode material comprising the active electrode material and the current collector material between two or more embossing rollers, wherein one or more of the two or more embossing rollers are structured with distributed elevations and depressions to provide a roughness to the electrode material characterized by:

[0088] (i) Ra: 0.005 pm < x < 15 pm;

[0089] (ii) Rz: 0.1 pm < x < 25 pm;

[0090] (iii) RmaX: 0.1 < x < 25 pm; and / or

[0091] (iv) Sa: 0.005 pm < x < 15 pm;

[0092] (v) Sz: 0.1 pm < x < 25 pm;

[0093] (vi) SmaX: 0.1 < x < 25 pm.

[0094] NAI-5008118396vl - 8 - Any of the above-mentioned roughness characteristics also apply to the aforementioned embodiment.

[0095] The inventive method is generally a calendaring / embossing method in which the respective electrode is formed by a system consisting of several embossing rollers arranged on top of each other and / or arranged side by side, through the gaps of which the respective materials are fed in order to be laminated and or pressed. The system may comprise only one pair of interactive embossing rollers or may be a system with two or more subsequent pairs of interacting embossing rollers.

[0096] According to the present invention, one or more of the embossing rollers are structured with distributed elevations and depressions to provide a roughness to the electrode material. Elevations and depressions mean that the surface of one or more embossing rollers is not smooth but has a pattern groove.

[0097] In one preferred embodiment the surface roughness is a non-periodical surface roughness, i.e., the pattern of elevations and depressions is irregular and does not have any repeating pattern. This irregularity ensures that there is no direction in which the forming and maturation is quicker or more effective, i.e., the time for the electrolyte to be evenly distributed throughout the cell and to be absorbed by the electrodes is the same in all directions. The surface roughness is characterized by any of the numbers (i) to (vi) provided herein.

[0098] The structure of the one or more embossing rollers may be generated by methods and techniques known to the skilled person. Generally, the method must be suitable to produce the required roughness based on the material of the embossing roller. In one embodiment, the surface roughness is generated by laser treatment. Any kind of laser may be used for producing the surface roughness, such as lasers producing radiation in several modes with slightly different wavelengths or lasers emitting a broad spectrum of light or emitting different wavelengths of light simultaneously. Also, lasers with different pulse length such as, but not limited to, CW, nano-, pico- and / or femto-pulse length may be used.

[0099] Compared to other surface treatment processes the use of the laser has the advantage that nearly all materials can be structured. For example, detrimental etching treatments of surfaces can be avoided, as, for example, etching of chromium surfaces can lead to environmental problems.

[0100] NAI-5008118396vl - 9 - In a preferred embodiment, picosecond lasers that generate ultra-short light pulses in the picosecond range (pulse duration between 10'9and 10'12s) are used.

[0101] In one embodiment, the laser treated surfaces are metal plated subsequently. Such treatment may be further strengthening the surface of the embossing roller. Exemplary surface treatments may be a metal plating, such as chromium plating, metal carbide plating, or the like. The metal plating may provide the hardness provided herein.

[0102] Generally, the process for producing the surface roughness may be carried out parallel to the laminating process or may be carried out separately. In the lamination process, the active electrode material is laminated on only one side or both sides of the current collector material. In the latter case, lamination takes place either consecutively or in a parallel lamination step. According to one embodiment of the invention, the laminating process is carried out in the same unit in that the surface roughness is produced and provided. In the process, the same or different active electrode materials may be used.

[0103] In another embodiment, the laminating process is carried out in a separate laminating unit. Thus, the active electrode material is placed on the current collector and is laminated before being embossed between the embossing rollers, such as in a different embossing unit, in order to provide the surface roughness.

[0104] In another embodiment, the active electrode material is placed on the current collector and is laminated simultaneously during the step of embossing between the embossing rollers within the same unit.

[0105] In the inventive process, one or more of the embossing rollers may be structured. In one embodiment, only one embossing roller is structured. In case only one embossing roller is structured, only one side of the active electrode material is structured.

[0106] In another embodiment two embossing rollers are structured. In case two embossing rollers are structured, both sides of the active electrode material are structured. According to the invention, in case two or more embossing rollers are structured, the two or more embossing rollers may have the same structured surface or may have differently structured surfaces. In a preferred embodiment, the two or more embossing rollers have the same structured surfaces.

[0107] NAI-5008118396vl - 10 - In one further embodiment, subsequent pairs of embossing rollers have a different surface roughness, providing an even more non-periodical surface roughness result.

[0108] The one or more embossing rollers are made from a material that has a hardness so that the roughness on the rollers, i.e., the elevations and depressions, is not affected by the embossing and / laminating process. In one embodiment, the embossing rollers have a Vickers hardness of > 750 HV, such as > 1000 HV, > 1250 HV, > 1500 HV, or > 1750 HV, or even more, but is not limited to.

[0109] The embossing rollers may have surfaces at least partly comprising chromium, ceramic materials, metal carbides and / or steel alloys. The materials have the advantage that the introduction of foreign substances into the surface during the treatment can be avoided, at least reduced.

[0110] The surface roughness may be measured mechanically, optionally using a distance needle and / or optically, optionally using microscopy, optional confocal microscopy, a stereo camera system and / or structured light 3-D scanner.

[0111] In another aspect, the present invention is directed to an electrode for a secondary battery prepared according to the methods provided herein.

[0112] In a still further aspect, the present invention is directed to an embossing roller comprising a surface roughness structured with distributed elevations and depressions characterized by: Ra: 0.005 pm < x < 15 pm;

[0113] Rz: 0.1 pm < x < 25 pm;

[0114] RmaX: 0.1 < x < 25 pm; and / or

[0115] Sa: 0.005 pm < x < 15 pm;

[0116] Sz: 0.1 pm < x < 25 pm;

[0117] Smax: 0.1 < x < 25 pm.

[0118] The surface roughness of the embossing roller may be as defined above. In one embodiment, the surface roughness is a non-periodical surface roughness, wherein optionally the surface

[0119] NAI-5008118396vl - 11 - roughness is generated by laser treatment. The laser treatment may be carried out by picosecond lasers.

[0120] According to the present invention, the embossing roller may be made from a material having a Vickers hardness of > 750 HV.

[0121] In a still further aspect, the present invention is directed electronic device comprising a secondary battery as provided herein.

[0122] Further details of the invention are explained with reference to the figures below.

[0123] Fig. 1 depicts an embodiment of the present invention in which the roughness is provided to the surface of the active electrode material by one embossing roller while simultaneously said active electrode material is laminated to the current collector.

[0124] Fig. 2 depicts an embodiment of the present invention in which an already laminated active electrode material / current collector is embossed between two embossing rollers, wherein one embossing roller is structured.

[0125] Fig. 3 depicts an embodiment of the present invention in which an active electrode material layered on both sides of a current collector is simultaneously laminated and provided with surface roughness on both sides of the active electrode material.

[0126] Figs. 4a-4d is an illustration of the distribution of a drop of LiPFe ECZEMC = 50 / 50 on an unembossed area in comparison to the distribution on an embossed area.

[0127] Fig. 5 is an exemplary confocal microscopic image of the surface of one embossing roller of used in the present invention to provide the surface roughness.

[0128] Fig. 6 is an exemplary confocal microscopy measurement of the surface of one embossing roller of used in the present invention to provide the surface roughness.

[0129] Fig.7 is a schematic illustration of a non-periodic surface roughness of an embossing roller.

[0130] NAI-5008118396vl - 12 - Figs. 8a and 8b are confocal microscopic images of one embodiment of a non-periodic surface roughness of an embossing roller.

[0131] Figs. 9a and 9b are confocal microscopic images of a further embodiment of a non-periodic surface roughness of an embossing roller.

[0132] Fig. 1 illustrates one embodiment for providing the roughness to the surface of the active electrode material. The active electrode material 1 is transported via rollers to a pair of interacting embossing rollers, wherein one of these embossing rollers 3 has a structured surface according to the present invention. Parallel to providing the surface roughness to the active electrode material 1, the latter is laminated between two embossing rollers onto the necessary current collector 2 which is separately provided to this part of the manufacturing process.

[0133] Fig. 2 illustrates another embodiment of the manufacturing process of the present invention. In this embodiment, a layer 4 in which the active electrode material is already laminated to both sides of the current collector is embossed between embossing rollers, one, roller 3, of which has a claimed surface roughness, whereas the other, roller has a, optionally compared to roller 3, smooth surface. This leads to a laminate 5 having a structured electrode material on one side.

[0134] Fig. 3 illustrates a further embodiment of the present invention. In this embodiment, a current collector with an active electrode material laid thereon on both sides 6 (but not yet laminated), is processed between two surface structured embossing rollers 3 to provide a structured surface according to the claimed subject matter on both sides of the active electrode material. Simultaneously, the layers are laminated to each other to provide the final laminated film. In another embodiment an already laminated film 4 may be processed between two surface structured embossing rollers to provide the final structured product. The two surface structured embossing rollers 3 may have the same surface roughness or different surface roughness.

[0135] Figs. 4a-4d show a comparison of the distribution time of a drop of LiPFe ECZEMC = 50 / 50 on an unembossed area and an embossed area. Fig. 4a shows the situation after application of the drop on the unembossed area. In Fig. 4b a second drop is provided 5s after the first drop, this time, however, the application is in the embossed area. Fig. 4c shows the situation after 50 s. It can be clearly seen that the drop in the embossed area, i.e., the struted area, is already starting to disappear, which means that it is much faster distributed within the layer. Finaly, Fig. 4d

[0136] NAI-5008118396vl - 13 - shows the situation after 2:51 min, where it can be seen that the upper drop on the unembossed area slowly starts to disappear whereas the lower drop on the embossed area is already completely distributed in and on the material.

[0137] Fig. 5 is an exemplary confocal microscopic image of the surface of one embossing roller of used in the present invention to provide the surface roughness.

[0138] Fig. 6 is an exemplary confocal optical measurement of the surface of one embossing roller of used in the present invention to provide the surface roughness. The measurements show the non-periodical surface roughness of the embossing roller, which is transferred to the active electrode material upon the respective embossing step provided herein.

[0139] Figs. 7, 8a, 8b, 9a and 9b are illustrations of a non-periodic surface roughness of inventive embossing rollers prepared as provided herein. The structures are formed by laser treatment and are chrome plated afterwards. The confocal microscopic images of different embodiments illustrate the non-periodicity which adds to the claimed effect that the electrolyte more easily moves between the spaces of the current collector material, active electrode material (and separator) and is much faster absorbed by the respective materials.

[0140] The features described or disclosed in the foregoing description, the claims and the figures may be essential to the invention in its various embodiments, either individually or in any combination.

[0141] NAI-5008118396vl - 14 - Reference signs

[0142] 1 - layer of active electrode material

[0143] 2 - layer of current collector

[0144] 3 - structured / embossed roller

[0145] 4 - current collector with active electrode material

[0146] 5 - structured active material

[0147] 6 - current collector with active electrode material layered on both sides (not laminated)

[0148] NAI-5008118396vl - 15 -

Claims

Claims1. A secondary battery comprising• one or more electrode(s) comprising a current collector material located adjacent to at least one active electrode material; wherein at least one side of the one or more electrode(s) has a surface roughness characterized by:(i) Ra: 0.005 pm < x < 15 pm;(ii) Rz: 0.1 pm < x < 25 pm;(iii) RmaX: 0.1 < x < 25 pm; and / or(iv) Sa: 0.005 pm < x < 15 pm;(v) Sz: 0.1 pm < x < 25 pm;(vi) SmaX: 0.1 < x < 25 pm.

2. The secondary battery of claim 1, wherein the roughness is characterized by:(i) Ra: 0.05 pm < x < 13 pm(ii) Rz: 0.5 pm < x < 25 pm(iii) RmaX: 1 < x < 25 pm; and / or(iv) Sa: 0.05 pm < x < 13 pm;(v) Sz: 0.5 pm < x < 25 pm;(vi) S max^ 1 < X < 25 pm.

3. The secondary battery of claim 1 or 2, wherein the secondary battery comprises an electrolyte.

4. The secondary battery of any one of the preceding claims, wherein the surface roughness is a non-periodical surface roughness.

5. The secondary battery according to one of the preceding claims, wherein the active electrode material comprises a negative active electrode material and / or a positive electrode material.NAI-5008118396vl - 16 -6. The secondary battery according to one of the preceding claims, wherein a negative active electrode material is located on a first side of a current collector material and the surface roughness is present on the surface of the negative active electrode material being distanced from and / or not in contact with the current collector material.

7. The secondary battery according to one of the preceding claims, wherein a positive active electrode material is located on a first side of a current collector material and the surface roughness is present on the surface of the positive active electrode material being distanced from and / or not in contact with the current collector material.

8. The secondary battery according to any one of claims 1 to 5, wherein the current collector material is located between at least two active electrode materials.

9. The secondary battery according to claim 5 or 8, wherein at least one first active electrode material is located on a first side of the current collector material and least one second active electrode material is located on second side of the current collector material, optionally facing away from the first side of the current collector material.

10. The secondary battery according to claim 9, wherein(i) the first active electrode material and the second active electrode material comprise negative active electrode materials;(ii) the first active electrode material and the second active electrode material comprise positive active electrode materials; and / or(iii) the first active electrode material comprises a negative active electrode material and the second active electrode material comprises a positive active electrode material.

11. The secondary battery of claim 10, wherein(a) the negative active electrode material is located on both sides of the current collector material and wherein the surface roughness is present on one surface of the negative active electrode material being distanced from and / or not in contact with the current collector material;(b) the negative active electrode material is located on both sides of the current collector material and wherein the surface roughness is present on both surfacesNAI-5008118396vl - 17 -of the negative active electrode material being distanced from and / or not in contact with the current collector material;(c) the positive active electrode material is located on both sides of the current collector material and wherein the surface roughness is present on one surface of the positive active electrode material being distanced from and / or not in contact with the current collector material;(d) the positive active electrode material is located on both sides of the current collector material and wherein the surface roughness is present on both surfaces of the positive active electrode material being distanced from and / or not in contact with the current collector material;(e) both the negative active electrode material is located on both sides of the current collector material and the positive active electrode material is located on both sides of the current collector material and wherein the surface roughness is present on both surfaces of the negative and positive active electrode material being distanced from and / or not in contact with the current collector material;(f) the negative active electrode material is located on the first side of the current collector and the positive active electrode material is located on the second side of the current collector and the surface roughness is present on the surface of either the negative active electrode material or positive active electrode material being distanced from and / or not in contact with the current collector; or(g) the negative active electrode material is located on the first side of the current collector and the positive active electrode material is located on the second side of the current collector and the surface roughness is present on both the surface of the negative active electrode material and the positive active electrode material being distanced from and / or not in contact with the current collector.

12. Method for manufacturing an electrode for a secondary battery defined in any one of claims 1 to 11, the method comprises embossing the electrode material comprising the active electrode material and the current collector material between two or more embossing rollers, wherein one or more of the two or more embossing rollers are structured with distributed elevations and depressions to provide a roughness to the active electrode material characterized by:(i) Ra: 0.005 pm < x < 15 pm;(ii) Rz: 0.1 pm < x < 25 pm;NAI-5008118396vl - 18 -(iii) RmaX: 0.1 < x < 25 un; and / or(iv) Sa: 0.005 un < x < 15 pun;(v) Sz: 0.1 pun < x < 25 pun;(vi) SmaX: 0.1 < x < 25 pun.

13. Method for manufacturing an electrode for a secondary battery according to claim 12, wherein the active electrode material is placed on one side or both sides of the current collector material and is laminated prior to being embossed between the embossing rollers.

14. Method for manufacturing an electrode for a secondary battery according to claim 13, wherein the active electrode material is placed on both sides of the current collector material and wherein the same or different active electrode materials are used.

15. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 14, wherein laminating is carried out in a separate laminating unit.

16. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 14, wherein the active electrode material is placed on the current collector and is laminated simultaneously during the step of embossing between the embossing rollers.

17. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 16, wherein only one embossing roller is structured.

18. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 17, wherein two embossing rollers are structured.

19. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 18, wherein the surface roughness is a non-periodical surface roughness.

20. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 19, wherein the structure of the one or more embossing rollers is generated by laser treatment.NAI-5008118396vl - 19 -21. Method for manufacturing an electrode for a secondary battery according to claim 20, wherein the laser treatment is carried out by picosecond lasers.

22. Method for manufacturing an electrode for a secondary battery according to any one of claims 12 to 21, wherein the one or more embossing rollers are made from a material having a Vickers hardness of > 750 HV.

23. An electrode for a secondary battery prepared according to a method of any one of claims 12 to 22.

24. An embossing roller comprising a surface roughness structured with distributed elevations and depressions characterized by:Ra: 0.005 pm < x < 15 pm;Rz: 0.1 pm < x < 25 pm;RmaX: 0.1 < x < 25 pm; and / orSa: 0.005 pm < x < 15 pm;Sz: 0.1 pm < x < 25 pm;Smax: 0.1 < x < 25 pm.

25. The embossing roller according to claim 24, wherein the surface roughness is a nonperiodical surface roughness.

26. The embossing roller according to claim 24 or 25, wherein the surface roughness is generated by laser treatment.

27. The embossing roller according to claim 26, wherein the laser treatment is carried out by picosecond lasers.

28. The embossing roller according to any one of claims 24 to 27, wherein the one or more embossing rollers are made from a material having a Vickers hardness of > 750 HV.NAI-5008118396vl - 20 -29. An electronic device comprising a secondary battery defined in any one of claims 1 to 11.NAI-5008118396vl - 21 -

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