KR100686611B1 - Electrochemical device and method of using the same - Google Patents

Abstract

The present invention relates to an intrinsically metallic target for a negative electrode sputtering device, in particular a negative electrode sputtering device assisted by a magnetic field, the target mainly comprising alloy nickel to reduce or eliminate ferromagnetic properties, and at least other elements In a smaller proportion. The invention also relates to a method of using a target to produce a thin layer of colored anodic electrochromic material based on alloy nickel.

Description

ELECTROCHEMICAL DEVICE AND METHOD OF USING THE SAME

The present invention relates to an electrochemical device, and more particularly to an electrically controlled system having variable optical and / or energy characteristics of electrochromic glazing or mirror type. will be.

In a known manner, the electrochromic system comprises a layer of electrochromic material capable of reversibly inserting ions and electrons at the same time, the oxidation state of which corresponds to the deinserted state, which is clearly colored. One state exhibits better light transmission than the other, and the insertion and exit reactions are controlled by a suitable electricity supply. Thus, electrochromic materials, generally based on tungsten oxide, should be placed in contact with an electron source, such as a transparent electrically conductive layer, and an ion (cationic or anion) source, such as an ion conducting electrolyte.

In addition, to ensure at least a hundred switch operations, it is known that the layer of electrochromic material must also be coupled with a counterelectrode capable of reversibly inserting ions and symmetrical with respect to the layer of electrochromic material. The electrolyte is simply a medium of ions.                 

The counter electrode should consist of a color-neutral layer, or a layer which is at least transparent or only slightly colored when the electrochromic layer is colored. Since tungsten oxide is a cathodic electrochromic material, ie its colored state corresponds to the most reduced state, an anode electrochromic material based on nickel oxide or iridium oxide is generally used for the counter electrode. For example, it has also been proposed to use organic materials such as cerium oxide or electrically conductive polymers (such as polyaniline) or materials whose oxidation state is optically neutral, such as prussian blue.

Descriptions of such systems will be found, for example, in European patents EP-A-0 338 876, EP-A-0 408 427, EP-A-0 575 207 and EP-A-0 628 849.

Such systems can be divided into two categories according to the type of electrolytes they currently use.

⇒ the electrolyte is a proton-conducting polymer, for example as disclosed in European patents EP-A-0 253 713 and EP-A-0 670 346, or patent EP-A-0 382 623, EP It is in the form of a polymer or in the form of a gel, which is a lithium ion conductive polymer as disclosed in -A-0 518 754 or EP-A-0 532 408.

Or an electrolyte is a mineral layer that conducts ions but is electrically insulated, such a system is referred to as an "all-solid" electrochromic system. For a description of the "all solid" electrochromic system, reference may be made to European patent applications EP-A-0 867 752 and EP-A-0 831 360.                 

The present invention most particularly aims to obtain a layer of cathodic electrochromic material based on nickel oxide, which can form part of such an electrochromic system.

As mentioned above, nickel oxide is known to have this property and is specifically described in patent EP-0 373 020 B1.

However, these materials have disadvantages. Certain difficulties arise in manufacturing this in thin layer form by magnetic-field-assisted reactive cathodic sputtering, which is a standard vacuum deposition method. Since nickel is ferromagnetic using standard nickel targets and standard magnets, the magnetic field generated at the target surface is weak, resulting in low deposition rates and medicre exploitation of the target.

This type of material is also studied in patent application WO 98/14824, and in applications for electrochromic mirrors, studies have been carried out on nickel oxides alloyed with other metals such as vanadium, chromium, manganese, iron or cobalt, and such compositions The change in is said to enhance the mirror's function and specifically give it a more uniform color.

However, injecting other metals into the nickel oxide in this way appears to pose a danger to the optical and electrochemical properties of the nickel oxide. Thus, for example, the injection of vanadium and chromium (its oxide absorbs in the visible region) makes nickel oxide more absorbable, thus reducing the overall light transmission value of the active system in the uncolored state. There is this. Similarly, the implantation of manganese, iron and cobalt reduces the durability of the layer and thus is likely to reduce the durability of the active system as a whole.

Accordingly, it is an object of the present invention to ameliorate these drawbacks by proposing a new method of producing nickel oxide specifically having anodic electrochromic properties, and in particular, such a manufacturing method impairs the desired function of nickel oxide even in other cases. Faster, more economical, and simpler to perform. This "function" is especially for its stability, durability, which works in electrochromic systems, most specifically for its stability and durability of the H ⁺ conductive type or the Li ⁺ conductive type and the "all solid" type, This is for transparency in the discolored state when in the thin layer.

Firstly, the object of the present invention is a basic metal target of the negative electrode sputtering apparatus, which is preferably a device by a magnetic field, in a reaction environment in the presence of oxygen, specifically to obtain a thin metal layer of the metal oxide, wherein the target mainly comprises nickel. It is alloyed with at least one other minor element to reduce or even eliminate its ferromagnetic, while at the same time preserving the possible optical and / or electrochemical properties of the alloy nickel oxide layer obtained from this target.

More specifically, the present invention allows the use of nickel oxide based layers at a faster rate and better economy of the target by reaction sputtering without compromising their functionality, and by adding carefully selected elements to the target. Provide a solution. The maximum effect by the gain in manufacturing efficiency is achieved by completely removing the ferromagnetic properties of nickel, but simply reducing it by appropriately changing the chemical properties of the added elements and the amount of these elements mixed in the target can be chosen. have.

In general, the proportion of such minor element (s) in the alloy is no greater than 20 atomic%, preferably not particularly greater than 18%, relative to the bound nickel + minor element (s), for example 3% and 15% Between.

For the present invention, the term "nickel oxide" refers to nickel which can be hydrated and / or hydroxylation and / or protonated (and optionally nitride-treated) to some extent. Means oxide. Similarly, the stoichiometry between nickel and oxygen can generally vary with Ni / O ratios between 1 and 1/2. However, nickel can generally be considered to be predominant in the oxidation state of +2.

Different modifications are possible to the chemical properties of the target, which are either selective or cumulative.

The first variant consists of these minor elements (denoted by the term "additives" below for simplicity), which are metals whose oxides are electrochromic materials with anodic coloring. It may specifically be at least one of the following metals: Ir, Ru, Rh. Ideally, this is also most particularly the case for iridium, where the oxide has an operating voltage range equal to or close to nickel oxide. Without destroying the function of nickel oxide, the additive makes it possible to maintain it and, if possible, increase its reversible ion insertion capacity. In this case, it is conceivable to reduce the thickness of the layer while maintaining the same level of optical / energy change as the change of the thicker layer of nickel oxide.

The second variant consists of an additive, which is a metal whose oxide is an electrochromic material with cathodic coloring. It may specifically be at least one of the following metals: Mo, W, Re, Sn, In, Bi. Injecting such materials into nickel oxide in this way can be seen as paradoxical and disruptive. In fact, the metal oxides described above have the ability to insert cathode ions in the operating voltage range above the potential reached by the nickel oxide used as the anode electrochromic material. Thus, these additives, which are effectively found in oxidized form in nickel oxide, are inert, and remain colorless when the nickel oxide is subjected to color change by being placed under tension. These additives are neutralized when the active system is in operation and do not reduce the degree of light transmission in the decolorized state. On the other hand, their presence tends to reduce the ion insertion capacity of the layer as a whole, and therefore it is possible to slightly increase its thickness if necessary to compensate for this phenomenon, and this measurement is also conceivable for all subsequent deformations. Can be.

The third variant consists of additives made of metals, alkaline earth metals or semiconductors in which the hydrated and / or hydroxylated oxides are proton conductors. It may specifically be at least one of the following metals: Ta, Zn, Zr, Al, Si, Sb, U, Be, Mg, Ca, Y. These materials in oxidized form do not have noticeable electrochromic properties. On the other hand, these materials are known to have the property of acting as a material that can act as a proton conducting electrolyte in the electrochromic system. Such materials do not inherently improve the electrochromic properties of nickel oxide, but do not adversely affect its function but may rather improve the stability of hydroxylation / hydration which may be desirable for nickel oxide. Of course, it should be noted that this modification is primarily for electrochromic systems acting by reversible insertion of protons H ⁺ .

The fourth variant consists of an additive, which is an oxide whose metal is hygroscopic, which is characterized by the fact that the associated electrochromic system works by the insertion / deletion of ions, most specifically cations such as protons. It is also advantageous when doing. Such additives are generally alkali metals, specifically Li, Na, K, Rb, Cs. In the oxidized form of nickel oxide, when nickel oxide acts as a bipolar electrochromic material in an electrochromic system, and most particularly when the nickel oxide is hydrated / hydroxylated, such material increases the retention of water in the layer, thereby It is found to increase the stability of the oxide.

Preferred embodiments of the target of the present invention are Ni / Si, Ni / Al, Ni / Sn, Ni / W, Ni / Zn, Ni / Ta and Ni / Y alloys, with the three alloys being the cheapest to manufacture. Alloy targets are produced by methods known in the vacuum deposition art, for example, by hot sintering of alloyed metal powders. An indication of the atomic ratio of some additives to all conceivable alloys is shown below, and this ratio is adjusted to completely eliminate the ferromagnetic properties of the target.

For Ni / W alloys, it is necessary to provide about 7 atomic percent tungsten W.

⇒ For Ni / Zn alloys, it is necessary to provide about 18 atomic% zinc Zn.

⇒ For Ni / Ta alloys, it is necessary to provide about 9 atomic% of tantalum Ta.

For Ni / Sn alloys, it is necessary to provide about 8 atomic% tin Sn.

⇒ For Ni / Si alloys, it is necessary to provide about 10 atomic% of silicon Si.

For Ni / Y alloys, it is necessary to provide about 3 atomic% yttrium Y.

However, as described above, for example, in order to limit the manufacturing cost of the target and / or to limit the arbitrary reduction of the function of the resulting alloy nickel oxide layer, an amount of additive less than the amount necessary to completely remove its ferromagnetic It can also be chosen to add to nickel.

The object of the present invention is also a method of producing a thin layer based on alloy nickel oxide, which is optionally hydrated and / or hydroxylated and / or protonated and / or nitrified, which is subject to oxidation reaction conditions from the target described above. Uses a cathode sputtering technique by a magnetic field.

The problem of the present invention is also the use of a method of producing an anode electrochromic material from a thin layer based on said oxide.

A subject of the present invention is also an electrochemical device comprising at least one carrier substrate having a stack of functional layers comprising at least one electrochemically active layer, which is H ⁺ , Li ⁺ And ions and electrons such as OH ⁻ can be reversibly and simultaneously inserted, and the layer is based on the oxide.

Such oxides can be obtained from a target, the composition of which is defined in the four variants described above. It should also be noted that, in general, the atomic ratio of the additive (s) to nickel in the target alloy is generally in the atomic ratio region of the additive to nickel in the oxide layer resulting from the conceivable target.

The addition of the additive according to the present invention to the nickel target is found to affect the structure of the oxide layer obtained from the present target. The presence of additives appears to be detrimental to the crystallization of nickel oxide. Thus, mainly amorphous layers are obtained with "grains" of small crystals, which are most specifically identified for additives of the W, Si and Li type. By approximating its shape almost spherical, such grains generally have a diameter of less than 50 nm, in particular at least 2 to 3 nm. It is advantageous to have a larger amorphous phase and / or smaller crystalline strain than in the case of standard nickel oxide, in an electrochemical device where the amorphous portion rather than the crystalline portion of the layer takes advantage of the electrochromic properties of nickel oxide. This is because it becomes active. The layer according to the invention thus generally does not have a sheet structure with an intercalation compound of Li type between sheets, but rather has an overall amorphous structure with a uniform distribution in grain.

The layer is optionally hydrated / hydroxylated and / or nitrified and alloyed with at least one additive whose oxide is an anodic electrochromic material such as Ir, Ro or Rh, or where the oxide is Mo, W, Re, Sn Alloyed with at least one metal that is a cathodic electrochromic material, such as In, or Bi, or a hydrated and / or hydroxyated oxide with Ta, Zn, Zr, Al, Si, Sb, U, Mg, La, or Y It may be based on nickel oxide alloyed with at least one alkaline earth metal or semiconductor which is the same proton conductor. Finally, this may allow the oxide to be alloyed with hygroscopic additives, for example alkali metals such as Li, Na, K, Rb or Cs.

It should be noted that the term "alloyed" has the following meaning. The additive is combined in the form of nickel oxide and oxide. This oxide may be in the form of a matrix formed from microdomains of nickel oxide, the interior of which is a microdomain based on the oxide of the additive. The system is also an accurate mixed oxide, where the nickel atoms are replaced with atoms of the present additive.

The preferred embodiment has a _{NiSi x O y, NiAl x O} y, NiSn x O y, NiW x O y, NiZn x O y, NiTa x O y and _x O _y NiY.

The obtained layer may also be hydrated and / or hydroxylated and / or protonated and / or nitrified and controlling the degree of hydration, protonation and / or hydroxylation and / or nitrification of the layer, In particular, it should be noted that by appropriately adjusting the cathode sputtering deposition parameters, for example by adjusting the composition of the reaction conditions during deposition (especially as contemplated in the electrolyte layer of patent EP-A-0 831 360). The reaction conditions may in particular comprise a certain amount of molecules in which at least one atom is nitrogen.

Finally, the task of the present invention is to use such electrochemical devices such that such electrochemical devices can form part of the electrochromic glazing. Such glazing can be embellished with external glazing or interior partitions or with glazing doors. It can also embellish any means of transportation such as trains, boats, airplanes, cars or vans with side panes, sunroofs and the like. It can also be used for display screen glazing, for example computer or television screens or touch screens, or in glasses, camera objectives and solar panel protection. It can also be used, for example, as a mirror for producing an anti-glare rearview mirror of an automobile (by sufficiently thickening one of the conductive layers and / or by adding an opaque coating). It may also be used in the manufacture of energy storage devices such as cells and batteries.

Other advantageous details and features of the invention will appear from various non-limiting embodiments below.

The following examples are so-called "all solid" electrochromic glazings.

Comparative Example 1

Glazing has the following sequence                 

Glass ⁽¹⁾ / SnO ₂ : F ⁽²⁾ / NiO _x H _y ⁽³⁾ / WO ₃ ⁽⁴⁾ / Ta ₂ O ₅ ⁽⁵⁾ / H _x WO ₃ ⁽⁶⁾ / ITO ⁽⁷⁾

4mm / 300nm 200nm 100nm 100nm 250nm 150nm

⇒ glass (1) is standard clean silicon-sodium-calcium flat glass,

⇒ The layer 2 made of fluorine-doped tin oxide is the first transparent conductive layer obtained by a known method by CVD,

⇒ The layer (3) made of NiO _x H _y is the opposite electrode, the anode electrochromic material of the system, the cathode in the presence of the reaction conditions of Ar / O ₂ / H ₂ from a nickel target containing about 99.95 atomic% nickel It is obtained by sputtering.

⇒ A layer 4 made of WO ₃ and a layer ₅ made of Ta ₂ O ₅ , which form an electrolyte, are deposited by a known method by cathode sputtering from a target made of W and Ta (especially patent EP- According to the teaching of A-0 867 752).

A layer 6 made of H _x WO ₃ is a layer of cathode electrochromic material which is deposited from a tungsten target by a known method by reaction sputtering.

The layer 7 made of tin-doped indium oxide is a second transparent electroconductive layer, which is also deposited by a known method by cathode sputtering from an alloy target made of indium and tin.

This glazing acts by proton transfer from one electrochromic layer to another by varying the potential difference produced over the glazing in a suitable way.                 

The layer 3 made of NiO _x H _y is difficult to obtain. Its deposition rate is only 4 nm.m / min. The target does not wear uniformly (its degree of wear is less than 5%).

Example 2 according to the present invention

This consists in substituting the layer 3 made of NiO _x H _y with the layer 3a made of NiSi _z O _x H _y of 250 nm thickness, the layer 3a made of NiSi _z O _x H _y . Silver is obtained by cathode sputtering under Ar / O ₂ / H ₂ reaction conditions from a Ni / Si alloy target having a Si atomic ratio of about 10% relative to Ni + Si.

Embodiment 3 according to the present invention

This consists in substituting the layer 3 made of NiO _x H _y with the layer 3b made of NiW _z O _x H _y of 250 nm thickness, the layer 3b made of NiW _z O _x H _y . The above is obtained from a Ni / W alloy target having a W atomic ratio of about 7% with respect to Ni + W.

Table 1 below shows the deposition rates (v) of the nickel oxide based layers obtained according to the three examples, which are expressed in nm.m / min (for deposition at 3.5 W / cm ²⁾ . ).

v Comparative Example 1 4 Example 2 20 Example 3 25

The glass coated with the above-described layer is provided with a power supply connected to a voltage generator in a known manner. This is then laminated to the same second glass as the first through a 1.25 mm thick polyurethane sheet.

The three laminated glazing samples were then subjected to a coloring / bleaching cycle (coloring by applying a voltage of about -1.2V and decolorizing by applying a voltage of about 0.8V). When the glazing sample is colored ("colored") and subsequently bleached ("bleached"), the light transmission values (in%) of a ^* and b ^{* in} the colorimetry system (L, a ^* , b ^* ) during light transmission ( T _L ) and% energy transmission value (T _E ) (reference for T _L measurement: emitter D ₆₅ ) were measured. Table 2 below contrasts all these data for the three glazing samples.

T _L a ^* b ^* T _E Comparative Example 1 coloring 13.6% -3.8 -2.9 10.2% decolorization 80.0% -2.4 7.2 67.2% Example 2 coloring 14.3% -3.5 -3.0 11.2% decolorization 79.2% -2.9 5.4 66.8% Example 3 coloring 12.2% -3.0 -3.5 9.8% decolorization 80.5% -2.3 5.6 67.9%

From these data, it is possible to confirm that the change in the electrochromic material based on nickel oxide does not affect its performance. The light transmission range and the energy transmission range obtained in Examples 2 and 3 according to the present invention are substantially the same as in Comparative Example 1, and the colorimetric display during transmission does not change significantly in any case. On the other hand, the deposition rate of the layer based on nickel oxide according to the present invention is at least five times faster than the deposition rate of the standard layer based on nickel oxide.

Claims (26)

As a metallic target of a cathodic sputtering device, In the target, the target contains nickel, The nickel is alloyed with any other hydrophobic element selected from Ir, Ru, and Rh to reduce or eliminate its ferromagnetic nature, the hydrophobic element having the oxide coloring of the anode A target, which is characterized in that the metal is an electrochromic material. The target of claim 1, wherein the proportion of the minority element (s) in the alloy is 20 atomic% or less. delete delete The method according to claim 1 or 2, wherein the hydrophobic element is characterized in that the oxide is any one metal selected from Mo, W, Re, Sn, In and Bi, which is an electrochromic material having cathode coloring. target. delete The hydrophobic element according to claim 1 or 2, wherein the hydrophobic element is one selected from Ta, Zn, Zr, Al, Si, Sb, U, Be, Mg, Ca, and Y. A target, characterized in that (hydrated or hydroxylated oxide) is a metal or alkaline earth metal or semiconductor that is a proton conductor. delete The said hydrophobic element is any one selected from Li, Na, K, Rb, and Cs, The oxide is a hygroscopic element, The alkali metal type element of Claim 1 or 2 characterized by the above-mentioned. Target. delete 3. Ni / W alloy (7 atomic% tungsten W), Ni / Zn alloy (18 atomic% zinc Zn), Ni / Ta alloy (9 atomic% tantalum Ta), Ni A target, which is made of a / Sn alloy (8 atomic% tin Sn), a Ni / Si alloy (10 atomic% silicon Si), or a Ni / Y alloy (3 atomic% yttrium Y). delete delete delete delete An electrochemical device comprising a carrier substrate having a functional layer stack comprising an electrochemically active layer capable of reversibly and simultaneously inserting ions and electrons such as H ⁺ , OH ^- and Li ⁺ , The layer is based on nickel oxide, the nickel oxide being hydrated or hydroxylated or protonated or nitrified, wherein any one is selected from the metals of the metals Ir, Ru, Rh, wherein the oxide is an anodically electrochromic material. An electrochemical device characterized by being alloyed with a minor element in the form of a metal. An electrochemical device comprising a carrier substrate having a functional layer stack comprising an electrochemically active layer capable of reversibly and simultaneously inserting ions and electrons such as H ⁺ , OH ^- and Li ⁺ , The layer is based on nickel oxide, the nickel oxide being hydrated or hydroxylated or protonated or nitrified and the metal of metals Mo, W, Re, Sn, In and Bi, wherein the oxide is an anodic electrochromic material. An electrochemical device, characterized in that an alloy with a minority element in the form of a metal selected from. An electrochemical device comprising a carrier substrate having a functional layer stack comprising an electrochemically active layer capable of reversibly and simultaneously inserting ions and electrons such as H ⁺ , OH ^- and Li ⁺ , The electrochemically active layer is based on nickel oxide, the nickel oxide being hydrated or hydroxylated or protonated or nitrified and the hydrated or hydroxylated oxide is a proton conductor, elements Ta, Zn, Zr, Al, An electrochemical device characterized in that an alloy is made of a metal selected from the elements Si, Sb, U, Be, Mg, Ca, Y or an alkaline earth metal or a hydrophobic element in the form of a semiconductor. An electrochemical device comprising a carrier substrate having a functional layer stack comprising an electrochemically active layer capable of reversibly and simultaneously inserting ions and electrons such as H ⁺ , OH ^- and Li ⁺ , The electrochemically active layer is based on nickel oxide, wherein the nickel oxide is hydrated or hydroxylated or nitrified and the oxide is hygroscopic and selected from the metals of the metals Li, Na, K, Rb, Cs. An electrochemical device, characterized in that the alloy is an element of the alkali metal type. Claim 17 according to any one of claims 18, wherein the layer of the nickel oxide based is, NiSi _x O _y, NiAl _x O _y, NiSn _x O _y, NiW _x O _y, NiZn _x O _y, NiTa _x O _y or Electrochemical device, characterized in that the NiY _x O _y form. delete H ^+, Li ⁺ and OH ^- ions and electrons as the reversibly and at the same time as an electrochemical device comprising a carrier substrate provided with a stack of functional layers, including electrochemical active layer that can be inserted, Said electrochemically active layer is based on the alloy nickel oxide obtained from the target of Claim 1 or 2, The electrochemical apparatus of the all-solids characterized by the above-mentioned. The metal target of claim 1, wherein the cathode sputtering device is a magnetic-field-assisted device. 3. The metal target of claim 2, wherein the proportion of the minority element (s) in the alloy is 18 atomic percent or less. 3. The metal target of claim 2, wherein the proportion of the minority element (s) in the alloy is 3 to 15 atomic percent. 20. A method of using the all-solid electrochemical device according to any one of claims 16 to 19 to form part of an electrochromic glazing for buildings or for vehicles such as trains, planes or automobiles.