FI130542B - Coated, pressed battery and method for producing the same - Google Patents

Abstract

The present invention presents a printed radiator (10, 20, 30, 40). In the battery, at least one electrode is produced by electrolytic plating (14, 27, 33). The second electrode can be made from a pasty material (12, 23, 36) by pressing. The coating material (14, 27, 33) may be zinc on the anode, and on the cathode side the current collector may consist of carbon (22) and/or silver (21). A plastic or aluminum film (42) can be fixed on top of the structure as a hermetic protection with the hot melting process. Using the principle of the invention, a UHF tag can also be manufactured, where the coated electrode acts as an RF emitter.

Description

COATED, PRINTED COOLER AND ITS MANUFACTURING METHOD

Engineering

The invention is related to printable electrical structures, and especially to printable electricity-storing structures, i.e. printed batteries or batteries, which also have possibly flexible properties.

Background of the invention

There have been many structural, manufacturing technical and property-related problems in the current printable battery, i.e. battery structures, as well as challenges related to costs. These are discussed below, along with a general structural description.

A printed battery usually consists of an anode paste and a cathode paste and an electrolyte that transports ions between the electrodes. In addition to these, the structure can include current collectors, unless the electrode itself functions as a current collector due to its good conductivity. Commercial radiators usually have either a metal or plastic shell, which binds the materials into a package and makes the structure airtight.

The printed structure can be coplanar or so-called stack (eng. stack; stacked, stacked or layered). When aiming for a thin structure, coplanar is better, but it uses a larger surface area — than a stack. Better capacity and lower internal resistance can be obtained with a stack structure, but the thick anode and cathode layers make manufacturing difficult. The biggest structural problem is both internal and inter-layer adhesion (i.e. stickiness) and, on the other hand, layer breakage. The goal is to achieve thin and or-

N wooden structure with the largest possible capacity. From the previous points,

N 25 — the capacity of the printed structures of the support is usually a fraction of the theoretical i.e. <Q calculated capacity.

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E Printable pastas generally use binders that keep the pasta

N in sass, but at the same time they weaken the capacity. A typical anode paste contains 50 2 30 —85% zinc particles, which are bound with e.g. CMC (i.e. carboxymethyl cellulose

S salla) to each other. Since in a printed radiator it is not possible to bind the structure ul-

In the same way, the binder must also be good enough for printing the following layers, i.e. electrolyte and cathode paste. The use of a gel-like electrolyte increases manufacturing technical problems, especially in the stack structure. A solid electrolyte is a mechanically more durable solution, but its problem is poor ion conductivity, which increases the internal resistance and limits the capacity.

In the prior art, publication EP 1655794 ("Chen 1") from November 2004 is presented. Chen 1 describes a stack-type printed circuit board structure, in which patent claims 7-12 deal with a secondary battery. The structure includes both electrodes as substrate & metal film type structures. Between the electrode layers is a circuit board layer as a laminated layer. The double electrode structure and the electrolyte are inside the protective shell. The substrate can be a traditional PCB material, but it can be — also a flexible, rollable material. Copper and aluminum are used as anode/cathode metals. The circuit board layer can be so-called FPC circuit, i.e. flexible circuit board.

In Chen 1's example at the end of the text, the anode and cathode are both mentioned as paste-type materials.

In another publication US 2016/0308173 ("Neudecker"), it is mentioned in section [0051], — that the cathode can be placed on the substrate using, for example, the slurry coating principle, which is one of the "non-vapor phase deposition methods" (many ways listed ). Pcs

[0052]-[0057] also describe matters related to cathode paste. The anode, on the other hand, starting from section [0071] is mentioned to be done by e.g. sputtering or the CVD method (i.e. chemical vapor deposition; English: Chemical Vapor Deposition). Flexibility is mentioned in section [0088] in two places. Neudecker's problem is that it is implemented with thin films that do not have sufficient capacity and the related manufacturing processes are expensive. In addition, Neudecker uses vaporized electrolyte, where vaporization is an expensive way to add material.

The printed radiators of the known technology are therefore associated with many significant problems, — related to both manufacturing technology, costs and productization, and

N also to the desired properties of the products.

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S Summary

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- In the present invention, the mentioned problems have been solved by introducing a new type of printed radiator structure. > 30 In other words, the present invention presents a printed battery, i.e. an electric

S chemical cell. The hallmark of the cell is that at least one of the cell's electrical

N rods are made by electrolytically plating metal on top of a conductive layer, where the cell is made on a flexible substrate.

In one application of the electrochemical cell according to the present invention, the structure of the cell is coplanar.

In one application of the invention, the structure of the cell is layered.

In one application of the invention, the electrolyte is printed or dispensed on top of the porous separator layer produced on top of the coated layer.

In one application of the invention, the cell is protected with a metallized film or a PET plastic film in such a way that the film is attached with glue to the lowest conductive layer.

In one application of the invention, the metallized film is aluminum.

In one application of the invention, the mentioned lowest conducting layer is copper. —In one application of the invention, the electrolytically produced coating is zinc.

In one application of the invention, a brass layer is formed on top of the conductive layer before electrolytic coating with the metal.

In one application of the invention, one of the electrodes of the cell consists of a paste-like spreadable material. — In one application of the invention, the electrolyte is produced by pressing or dispensing, and the electrolyte is either a solid electrolyte or an aqueous solution of the desired substance.

In one application of the invention, the electrolyte is an aqueous solution of potassium hydroxide, KOH.

In one application of the invention, the printed electro-

O C L . . yes s NN o

N 20 — a dielectric protective layer is placed on top of the lyte or on top of the current collector of the cathode in a layered structure. <Q

O In one application of the invention, the coated electrode is shaped so that it

I works as a radio frequency emitter. =

N In one application of the invention, the material of the seed layer of the cell is RA copper o 25 (Rolled Annealed copper).

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N In one application of the invention, at least one of the electrodes of the cell is a mixture, combination or laminated structure of an electrolytically produced coating of the first metal and a paste-like oxide of the first metal produced by pressing, and the cell is arranged to be charged to substantially full capacity during manufacture.

In one application of the invention, the current collector of the cathode can be made of silver or carbon, or of an overlapping layer of silver and a layer of carbon.

A brief description of the drawings

Figure 1 shows an example of the invention as a section view of the basic structure without a protective film,

Figure 2 shows an example of the layers of a coplanar printed structure, — Figure 3 shows an example of the structure of an alkaline zinc-silver cell (Zn-Ag) on copper (Cu), in stack type, i.e. so-called as a stack structure,

Figure 4 shows an example of the so-called hermetic protection of a printed radiator. using the hot-melt process and

Figures 5A-K show example structures of a printed battery where a coated electrode acts as an RF emitter.

Detailed description of the invention

The present invention presents a more affordable solution for a printed battery, i.e. for a battery, battery or other similar electrical energy storage device manufactured by pressing. Later we also talk about cells or battery cells, > 20 which also means the aforementioned devices.

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N Since the most optimal anode material in a battery is pure metal, it is advantageous <Q to make the anode by coating pure metal on top of the conductive layer. Invention

This is what is done in one application. The coating can be done with the selected vapor

E tation method from among several different vaporization methods, such as for example

N 25 with ALD (eng. Atomic layer deposition) or alternatively by sputtering (eng. sputtering), but electrolytic coating is more affordable and a commonly used method

Q statement in industry. It can also be implemented as a roller process in normal atmo-

O

N in the sphere and with it, the metal layer required by the anode can be easily produced, the so-called conductive on top of the seed-layer (the so-called starting layer) by adding the so-called required number of tanks. The most affordable seed-layer material is copper when copper is also used for other parts, such as the production of the circuit and antenna. The seed-layer can also be a graphite or other conductive polymer paste or a conductive plastic, provided that the conductivity of the material is sufficient for electrolysis to start. The seed layer can also be produced by vaporization or sputtering. 5

A porous separator film (i.e. separator or separator layer) is added on top of the coated anode in the stack structure, either by lamination or by pressing, the purpose of which is to bind the electrolyte and prevent the formation of dendrites growing from the metal. In the stack structure, the cathode paste is still pressed onto the separator membrane.

The use of a coated anode is also possible in a coplanar structure, and in this case the cathode is pressed next to the anode and the electrolyte on top of both of them.

Figure 1 shows one possible coplanar structure of the zinc-manganese battery (Zn-Mn) 10. In the structure of the battery 10 (i.e. the cell), the current collector 11 (engl. current collector) made of silver and carbon in this example can be seen as the lowest. This current collector can therefore be formed in such a way that there is a silver layer (Ag) below, on top of which a current collector layer (C) made of carbon is placed.

In this example, the positive battery pole 15 is connected to the current collector 11 with the first copper conductor 17. On top of the current collector 11 is a cathode paste 12, which does not — therefore, extend over the entire width of the structure, nor does the current collector 11. Since the structure is coplanar, next to the parts 11 and 12 in approximately the same plane is a zinc plate 14 placed separately from the cathode paste, which acts as an anode. Below the Zn anode 14 is a copper current collector 19. In one application, it can be thought that the Cu current collector 19 is like a substrate, and the anode 14 is formed by a coating formed on top of this substrate, which can be zinc. In this way, the Zn anode 14 is formed on top of the Cu current collector 19, where the anode 14, however, does not physically

S not in contact with parts 11 or 12. Current collector 19 as the connection wire to the negative

Another copper conductor 18 is connected to the battery terminal 16. Finally, the cathode paste 12 and zinc

On top of the N cyanode 14 is placed a planar electrolyte layer 13 with the width of the entire structure 0 30. The electrolyte layer 13 is in contact with both the cathode 12 and

I to anode 14. Since the structure is coplanar, its thickness can be considered relatively thin. & 3 Possible manufacturing methods of the zinc coating 14 on the Cu current collector 19 are shown in

S 35 — covered in more detail later.

Figure 2 shows a coplanar example structure 20 according to the invention (i.e. cell) with the layers separated and seen directly from the side as a cross-sectional view. —The current collector of the cathode (on the left in Figure 2) is formed by layers of silver 21 and carbon 22, where the silver layer is lower. A cathode paste 23 can be placed on top of the carbon layer 22. The side of the corresponding anode (on the right in the figure) is formed by a copper current collector 26, which is coated with a layer of zinc, where Zn therefore forms the anode 27. The top edge of the cathode paste can be at the same height as the top edge of the zinc anode. , but this does not have to be the case (as in the figure). Electrolyte 24 can be printed on both of these parts 23, 27, the material of which we will describe different examples of later. Finally, a dielectric protective layer 25 is placed on top of the printed electrolyte 24. — One alternative of the invention is to add the electrolyte 24 by dispensing instead of printing.

When the radiator is integrated into the circuit board structure, it is advantageous to use a copper conductor also as a current collector. In one application of the invention, copper is selected as the current collector material. In an alkaline battery, copper may react with the electrolyte and shorten the lifespan (an alkaline battery is based on the reaction between zinc and manganese dioxide, MnO>). With the help of zinc, it is possible to form a layer of brass (brass is a mixture of copper and zinc with the desired mixing ratio) between copper and zinc, which prevents copper corrosion. In this case, the zinc coating must be done in two parts, in which the zinc is converted to brass using high heat or other high-power energy, such as photonic sintering, plasma or corona treatment.

With the help of S ly, in one application of the invention.

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N Figure 3, on the other hand, shows an example of the structure of an alkaline Zn-Ag cell 0 30 — on copper, in stack type, i.e. so-called as a stack structure. The structure therefore describes a cell

I 30, seen directly from the side as a cross-sectional view. The anode-related current collector 31a = is at the bottom left, and this acts as the battery's negative electrode. A brass layer 32a is placed on top of this &. Zinc can be coated on brass 32a

S tight layer with the desired method, i.e. this is how a coated zinc layer 33 is created, which

S 35 — acts as an anode. A separator film 34 is made around the current collector (-) 31a, the brass layer 32a and the zinc layer 33, the function of which is to separate the anode 33 and the cathode 36, but still allows charge carriers to pass through. In this structure, the separator membrane 34 is therefore porous and saturated with an electrolyte, i.e. potassium hydroxide (KOH). The actual electrolyte (potassium hydroxide in this example) is visible in areas 35a and 35b, i.e. the electrolyte spreads from these areas to saturate the area of the separator membrane 34 below and on the sides. —The cathode paste 36 is then placed on top of the separator membrane 34 and also on the side (including the electrolyte areas 35a-b). The cathode current collector 37 is silver (Ag) in this example. After the current collector 37 of the cathode comes the brass layer 32b, and the current collector 31b, where the latter acts as the positive electrode of the battery. A dielectric protective layer 38 can be placed on top of the current collector 37 of the cathode as the uppermost layer of the structure.

Alkaline electrolyte 35a-b thus enables the alkaline 2Zn-Ag cell or battery according to Figure 3.

It should be noted that the structure and material choices in Figure 3 are only one possible example. Similarly, the dimensions in the pattern are only indicative, and many other dimensions between the parts are possible. — Next, an example of the hermetic protection of a printed radiator using the hot-melt process is presented and we refer to Figure 4.

Figure 4 therefore shows the electrochemical cell 40 directly from above. By using the lower copper layer 41 as a hermetic protection and adding e.g. a plastic or aluminum film 42 as the top protective layer of the radiator, the battery is hermetically protected. The plastic can be PET plastic. The protection can be pressed onto the substrate with hot-melt adhesive 43 or a similar type

S with that material as shown in Figure 4 (dotted areas). Hot melting areas 43

N (i.e. hot-melt type material areas) can be printed in a roll process and PET/AI

N film 42 can be laminated aligned also in the roll process. Part 44 is the positive electrode "+" (e.g. carbon; diagonally hatched area), and from the actual copper layer

The copper area separating from I 41 can act as a negative electrode at the same time "—". a & In a primary cell, the anode contains metal and the cathode metal oxide. Secondary

It is also possible to make a cathode by coating pure metal, which

S 35 — is oxidized in the charging process. In this case, the anode must be a conductive metal oxide, for example ZnO + Zn or ZnO + carbon (Sup-P). The charging process can be done before final manufacturing, so-called in bulk, or it can be done for a finished cell. By coating both electrodes, for example the cathode with silver and the anode with zinc, and by adding a conductive ZnO layer to the anode, a rechargeable cell is obtained in one example of the invention. By using temporary masks known per se from circuit board technology, it is possible to coat both electrodes on the same substrate separately with different metals. As described above, it is possible to make a hybrid cell, which is partly a primary cell, but which can also be charged. It can have coated zinc + printed ZnO paste on the anode, and silver + silver oxide on the cathode. When the cell is charged, ZnO is reduced to zinc (Zn) at the anode, while silver (Ag) is first oxidized to monovalent and in the next step to divalent silver oxide (Ag20). The advantage of such a hybrid cell is the good conductivity of the electrodes and better mechanical strength than with cells made only with printed pastes.

A cell is characterized by the fact that it is rechargeable, but already has a partial charge (ie it is already partially charged) due to the manufacturing process. The solution improves — the mechanical strength of the cell. Most radiator structures are so-called cathode-limited.

Since cathode materials are usually semiconducting metal oxides, their conductivity is weaker than that of metal anodes. Conductive carbon and often electrolyte must be added to the cathode paste in order to improve the mobility of ions in the cathode. The printed cathode must also contain a binding agent, with which the paste can be attached to the current collector (coplanar structure) or to the separator (stacked structure), and the adhesiveness of the binding agent to the aforementioned surfaces is essential for the operation of the battery. Especially in a stack structure, better mechanical strength is achieved with a coated anode compared to a structure where both electrodes are pastes. If fixing points for the separator are made in the structure according to Figure 4, a protective film can be attached in a hot-melt type process. to areas in the separator, which makes the structure more durable in this application of the invention. With this method, electro-

S lyte and cathode paste bond better to the substrate, but at the same time lose the

Effective surface area equivalent to N working areas. The same method also works for coplanar

N in that structure. 0 30

I In one example of the invention, the electrode material can also be a mixture of electrolytically coated material and printed material. For example, the printed anode paste can still be coated with zinc, or the silver oxide cathode can be

S bewitches with silver. The end result can be a cell with both electrodes

S 35 — half loaded. In this case, the cell is fully charged before commissioning, either in a separate roll process or as a finished cell. In the case of a silver oxide cell, the cathode can also be a mixture of silver oxide and silver particles, and the anode can be coated zinc and ZnO paste. In this case, the internal conductivity of both electrodes is good, which has a positive effect on the performance of the battery.

To work ideally, the metal/oxide ratio of both electrodes must be in balance.

In one application of the invention, the coated electrode of the battery is shaped in such a way that it functions as a radio frequency emitter. This example describes how to effectively manufacture, for example, an active UHF tag (UHF = ultra high frequencies) in the manner in question. By designing the radiator according to the conditions of a radiator (i.e. radiator), a good utilization rate of the material is achieved. Since the shape of the electrodes does not affect the capacity of the battery, only the surface area matters, and the battery can be shaped according to the examples in Figures 5A-K. The structures and dimensions shown are only some possible examples. Since high frequencies travel only on the surface of the conductor (so-called skin effect), the conductivity of the coated metal is significantly higher compared to the printed and poorly conductive cathode material. If the so-called the seed-layer is copper, only a layer of copper of a few micrometers is needed, in which case the coated metal, such as e.g. Zn, no longer affects the radiation power, because the conductivity of zinc is approx. 3.5 times weaker than that of copper. If the seed-layer is less conductive, a 4-5 um thick layer of zinc is needed at UHF frequencies.

However, other electrical properties of the cathode material affect the design of the radiator and cannot be ignored. For example, the damping properties of manganese oxide increase at frequencies above 1 GHz. Battery assisted ones on the market

UHF tags are based on a separate radiator and a separate radiator, which causes excessive costs and makes it difficult to scale production volumes and increases costs. The design must take into account possible cathode changes due to the discharge of the battery, which can cause a reduction in radiation power, and in addition, the effect of the battery terminals on the operation of the radiator itself must be taken into account.

S

The most affordable solution is to use the so-called seed layer RA copper (Rolled Annealed

N copper), in which case the antenna's power is best on the back side of the tag and not in the coating syn-

LO base rough material surface cause additional losses. In one embodiment of the invention, RA copper is selected as the material of the seed layer. In this case, the tag's glue is laminated on top of the radiator materials and the tag is installed upside down in a way

N facing. When the adhesive layer is thick enough, the tag in question can be installed with

LO to the stable surface.

S

N The advantages of the various application forms of the present invention are discussed next. — by using a coated anode, such as zinc and a slurry cathode,

the following benefits are achieved. First, due to the efficient anode reaction, the surface area of the anode can be reduced and the surface area of the cathode can be increased by a corresponding amount. Second, the structure can be made thinner, which improves mechanical strength. Thirdly, the structure is more flexible. As a fourth advantage, better adhesion (i.e. stickiness) to the coated metal is obtained also in the so-called in the hot-melt process.

The main additional advantages are the possibility of the roll-to-roll process (R2R; roll-to-roll), thin structure, high capacity per surface area, low internal resistance and flexibility of the structure without the risk of breakage. The adhesion of the coated anode is better than that of the printed one, which increases the structural strength and enables a structure almost 50% thinner than the printed anode. If high temperatures are required in the processing, other layers can be prepared for the coated anode at higher temperatures, provided that the substrate can withstand this. By using polyimide/copper laminate, we reach almost 300 degrees, which makes it possible to manufacture e.g. transistors, displays and other active components in connection with the battery.

The present invention is not limited only to the above examples, but the scope of protection of the invention is determined in accordance with the attached patent claims.

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Claims (17)

Patent Claims 1. An electrochemical cell (10, 20, 30, 40), in which the first of the cell's electrodes is made by electrolytically coating a metal (14, 27, 33) on top of a conductive layer (19, 26, 31a), in which the cell is made on a flexible substrate, — characterized in that one of the electrodes of the cell and the separator layer (34) are made by pressing, and the electrolyte (35a—b) is printed or dispensed on top of the separator layer (34), and the cell is protected by a metallized film or a PET plastic film (42). 2. Electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that the structure of the cell is coplanar. 3 Electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that the structure of the cell is layered. 4. Electrochemical cell (30, 40) according to claim 3, characterized in that the electrolyte (35a-b) is printed or dispensed on top of the porous separator layer (34) produced on top of the coated layer (33). 5. Electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that the cell is protected by a metallized film or a PET plastic film (42) such that the film (42) is attached with glue (43) to the lowest conductive layer (41) ). 6. Electrochemical cell (10, 20, 30, 40) according to claim 5, — characterized in that the metallized film (42) is aluminum. 7. Electrochemical cell (10, 20, 30, 40) according to claim 5 or 6, characterized in that said lowest conductive layer (41) is copper. OF Oh 8. Electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that the electrolytically produced coating (14, 27, 33) is zinc. < O I 25 9. Electrochemical cell (30, 40) according to claim 4, characterized in that a brass layer (32a) is formed on top of the conductive layer (31a) before electrolytic coating with metal (33). LO O N 10. Electrochemical cell (10, 20, 30, 40) according to claim 1, N characterized in that one of the electrodes (12, 23, 36) of the cell consists of a paste-like spreadable material. 11. Electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that the electrolyte (13, 24, 35a-b) is produced by pressing or dispensing and the electrolyte is either a solid electrolyte or an aqueous solution of the desired substance. 12. Electrochemical cell (10, 20, 30, 40) according to claim 11, — characterized in that the electrolyte (35a-b) is an aqueous solution of potassium hydroxide, KOH. 13. Electrochemical cell (10, 20, 30, 40) according to claim 2 or 3, characterized in that a dielectric protective layer (25, 38) is placed on top of the printed electrolyte (24) in a coplanar structure or on top of the cathode current collector (37) in a layered structure. . 14 The electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that the coated electrode (14, 19; 26, 27; 31a, 32a, 33) is shaped so that it functions as a radio frequency emitter. 15. Electrochemical cell (10, 20, 30, 40) according to claim 14, characterized in that the material of the seed layer of the cell is RA copper (Rolled Annealed copper). 16. Electrochemical cell (10, 20, 30, 40) according to claim 1, characterized in that at least one of the electrodes of the cell is a mixture, combination or laminated structure of an electrolytically produced coating of the first metal and a paste-like oxide of the first metal produced by pressing, and — the cell is arranged to be charged to essentially full capacity during manufacture. 17. Electrochemical cell (10, 20, 30, 40) according to claim 1, N characterized in that the current collector (21, 22) of the cathode can be made of silver or carbon or of an overlapping silver layer (21) and carbon layer (22). S < O I a a N o LO O N O N