TW201710544A - Solid electrolyte layers of LiPON or LiPSON and method for making such layers - Google Patents

Abstract

The present invention relates to a method of preparing solid electrolyte layers. In particular, a preparation of lithium oxynitride solid electrolyte layers on the basis of phosphate or a combination of phosphorus and sulfur is disclosed. A substrate, at least one reactive gas, at least one inert gas and a target are provided. Sputtering is performed within an atmosphere comprising at least one reactive gas and the at least one inert gas. The solid electrolyte layer is deposited on the at least one substrate. The target utilized for sputtering comprises a material having an electric conductivity which, during sputtering, is transformed into an inert compound (Fig. 3).

Description

LiPON or LiPSON solid electrolyte layer and method for preparing same

The present invention relates to a process for preparing a solid electrolyte layer, and in particular to the preparation of a lithium oxynitride solid electrolyte layer based on a phosphate or a combination of phosphorus and sulfur.

Rechargeable lithium-ion batteries are increasingly used today. The prior art lithium ion unit cell comprises a thin metal foil on which an electrolyte material in the form of a porous layer, such as graphite as an anode, and lithium cobalt oxide as a cathode, are applied. Herein, the anode and cathode are separated by a separator layer to avoid short circuits. The separator layer immersed in the liquid electrolyte herein also serves as a conductor of lithium ions.

The reason why the solid electrolyte is used as a separator layer is due to the preferable handling characteristics of stacking individual layers. These particular solid electrolyte comprising a so-called super-ionic conductor, or said ion conductor, each having their high conductivity and a polymeric matrix (e.g., such as poly (ethylene oxide)), and major salts (e.g., LiPF _6, LiBF _4, or Polymer electrolyte of LiClO ₄ .

The solid electrolyte layers used today are often based on the use of lithium phosphate as a starting material. Other elements or chemical compounds can be used. The solid electrolyte layer used in combination with a lithium ion unit cell must have a uniform chemical composition and must have a thin and fixed layer thickness. In order to obtain a lithium ion unit cell of high energy density, a solid electrolyte layer having a layer thickness of 10 μm or less is used. The difference in layer thickness should not exceed 10%. In particular, holes should be avoided in the solid electrolyte layer to avoid short circuits.

Sputtering methods are primarily used to produce layers that meet the above requirements. The atoms are extracted from the target by impact with energetic ions during sputtering or cathodic spraying, respectively. The atoms extracted by the impact are finally deposited on the substrate.

During sputtering, an blunt gas (such as argon) is ionized at low pressure. The voltage accelerates the ions towards the target. The plasma extracts atoms from the target, which are again deposited on the substrate.

Sputtering techniques known in the prior art include RF or RF sputtering, intermediate frequency or MF sputtering, and ion beam sputtering in addition to DC or DC sputtering. DC sputtering, RF sputtering, and MF sputtering can also be used as magnetron sputtering. In addition to this, reactive sputtering techniques are also known in which a reactive gas such as nitrogen is ionized and deposited on a substrate. A reactive sputtering technique using lithium phosphate as a target and nitrogen as a reactive gas is described in US 2009/0117289 A1. A modified phosphorus-containing lithium oxynitride (LiPON) layer is formed on the substrate. The RF sputtering used therein uses a high frequency alternating electric field to generate plasma not only from argon cations and electrons, but also to be simultaneously fed nitrogen. In this way, different materials can be incorporated into the deposited layer. Thus Different hydrides are used in which hydrogen is in the chamber volume and other portions are incorporated into the growth layer.

Disadvantages of this method are the high energy requirements necessary to generate a high frequency electric field, the irregularity of the layer thickness distribution in a large-sized substrate of 1 m ² or more, and the relatively low coating rate.

In view of the above, an object of the present invention is to provide a method for depositing a phosphorus-containing lithium oxynitride (LiPON) or a phosphorus or sulfur-containing lithium oxynitride (LiPSON) solid electrolyte layer as a thin layer having a uniform layer thickness on a substrate. . Coating methods suitable for substrates having large surfaces are also disclosed. Finally, if possible, the energy consumption during individual sputtering methods should also be reduced.

The object is achieved by a method of preparing a LiPON or LiPSON solid electrolyte layer comprising the steps of: providing at least one substrate, at least one reactive gas, at least one inert gas, and a target; comprising the at least one reactive gas and Sputtering at least one inert gas atmosphere; and producing a LiPON or LiPSON solid electrolyte layer on the at least one substrate; wherein the target comprises a conductive material, and wherein the conductive material is converted to inert during sputtering Compound.

According to another aspect of the invention, a LiPON or LiP _x S _(1-x) ON solid electrolyte layer is provided, which is obtainable by the method according to the invention, wherein x < 1.

According to another aspect of the invention, a thin layer battery, an electrochromic glass or an electrochromic foil is disclosed. The thin layer battery, the electrochromic glass, or the electrochromic foil comprises the LiPON or LiP _x S _(1-x) ON solid electrolyte layer of the present invention, wherein x < 1.

Finally, the present invention discloses a target for a sputtering process comprising the compounds lithium, phosphorus and oxygen, and their compounds. Further, the target contains nitrogen or sulfur, or contains nitrogen or sulfur, respectively. Also, it includes a material having electrical conductivity. The electrically conductive material is converted to an inert compound during sputtering, so the deposition functional layer typically does not contain any electron conducting components and thus satisfies the function of the electrolyte.

It has been unexpectedly discovered that a target for a sputtering process can be disclosed wherein the target contains electrical conductivity (and also has electron conductivity). By providing a target having electrical conductivity, it is possible to use a direct current sputtering method. The DC voltage used during DC sputtering is ionized by ionization of the inert gas by impact ionization, or the molecules of the reactive gas are dissociated by impact ionization. Constant ion motion within the DC electric field results in a higher and uniform precipitation rate. In this way, the surface of the large substrate can also be quickly applied to the layer of the thickness of the fixed layer.

Furthermore, the inventors have found that conductive targets suitable for producing LiPON or LiPSON solid electrolyte layers when using inert and reactive gases simultaneously can be obtained in different ways.

Therefore, it can be used in the target to cause conduction of the target. Different materials for sex. These materials are converted to "inert compounds" during sputtering. The inert compound in the deposited solid electrolyte layer is no longer present or only incorporated in a small amount or separately in different forms, so that the behavior of the layer of the solid electrolyte layer or the layer properties are not adversely affected. Therefore, electron conductive carbon such as graphite, carbon black, carbon nanotubes, or the like can be used to manufacture the conductive target. During the sputtering process, carbon can be almost completely converted to carbon monoxide or carbon dioxide by, for example, oxygen as a reactive gas, respectively in the gas phase, which can thus be removed by pumping, and thus not incorporated In the solid electrolyte layer. Furthermore, it is possible to use conductive polymers, such as olefins having conjugated double bonds, or possibly other conducts that also split into carbon monoxide, carbon dioxide and hydrogen-containing compounds and/or incorporate the solid electrolyte layer as a non-electron conductive compound. Polymer system. The target may also contain one or more salts, wherein the components forming the ions of the salt may also be deposited as a solid electrolyte layer or remain in the vapor phase. Exemplary cations include lithium and ammonium ions. Suitable anions are especially phosphates, sulphuric acid and nitrates.

It should be understood that the method according to the present invention is not limited to DC sputtering, but any type of sputtering method can be applied. For example, RF sputtering, MF sputtering, ion beam sputtering, and various variations and hybrid forms, such as magnetron sputtering, can also be used. Also, it is possible to use thermal vaporization of the conductive target. Moreover, the conductivity of the target makes it possible to directly heat the evaporated material, in particular by inductive coupling using an induction heater. Therefore, heat is not transferred to the evaporated material via the evaporation pot, but is directly coupled to the evaporated material. Further, electron beam evaporation and arc evaporation of a conductive target may be used. In addition, compared to Both LiPON and LiPSON targets have better heating and thermal conductivity. Thus, the evaporation rate can be increased. Also, carbon may be incorporated into the solid electrolyte layer resulting in an improvement in mechanical properties, such as fracture toughness of the deposited layer. It is also possible that the target has better mechanical properties, such as increased fracture toughness. Also, all other methods for physical vapor deposition (PVD method) can be used. Preferably, during the sputtering, a roll-to-roll method is also used, in particular for producing several layers. Better roll-to-roll DC sputtering.

Lithium oxynitride or a phosphorus-containing and sulfur-containing lithium oxynitride solid electrolyte layer often shows different stoichiometry of individual elements lithium, oxygen, nitrogen, phosphorus and possibly sulfur. The LiPON solid electrolyte layer according to the present invention may also be characterized by different levels of phosphorus. The LiPON solid electrolyte layer can thus be present in the form of a LiP _y ON solid electrolyte layer. Usually, 0 < y < 1.2. Preferably, y is in the range of 0.1 to 1.1; or 0.2 to 1.0; or 0.3 to 0.9; or 0.4 to 0.8 or 0.5 to 0.6, respectively, or 0.7, respectively. In the LiP _x S _(1-x) ON solid electrolyte layer, x<1 is usually used. Preferably, x is in the range of 0 < x < 0.7. More preferably, the x series is in the range of 0.1 to 0.6; or 0.15 to 0.55; or 0.2 to 0.5; or 0.25 to 0.45; or 0.3 to 0.4; or 0.32 to 0.38, or 0.34 to 0.36, respectively. It will be appreciated that the method according to the invention also makes it possible to obtain the above described individual stoichiometric LiP _y ON or LiP _x S _(1-x) ON solid electrolyte layers.

The solid electrolyte layer according to the present invention is a thin layer having a layer thickness of usually between 50 nm and 250 μm. The thickness of the layer is preferably between 100 nm and 200 μm, or between 200 nm and 150 μm. Between 300 nm and 100 μm, or between 400 nm and 90 μm, or between 500 nm and 80 μm, or between 600 nm and 70 μm, or between 700 nm and 60 μm, or between Between 800 nm and 50 μm, or between 900 nm and 40 μm, or between 950 nm and 30 μm, or between 980 nm and 25 μm, or between 1 μm and 20 μm, or between 1 μm and 15 μm Or between 1 μm and 10 μm, or between 1 μm and 8 μm, or between 1 μm and 6 μm. The optimum is a layer thickness between 1 μm and 4 μm.

The thickness variation of the layer in the deposited solid electrolyte layer is less than 20% of the thickness of the layer, preferably less than 10%, or less than 9%, or less than 8%, or less than 5%, or less than 3%, or less than the thickness of the layer. 2%, or less than 1%.

The term "substrate" refers to a material on which a solid electrolyte layer according to the present invention is deposited. Several substrates can be used. The surface of the substrate can be in the range of several cm ² up to 1 m ² or more. Thus, the substrate can have a surface between 1 cm ² and 3 m ² . Preferred substrate surfaces include 10 cm ² , or 100 cm ² , or 500 cm ² , or 1000 cm ² , or 5000 cm ² , or 1 m ² , or 1.1 m ² , or 1.2 m ² , or 1.3 m ² , or 1.4 m ² , or 1.5m ² . Larger substrate surface areas are also possible. The roll-to-roll DC sputtering method can be used to prepare a substrate having the above-described area on a low cost basis.

The term "reactive gas" refers to a gas that splits during the sputtering process and is partially or fully incorporated into a LiPON or LIPSON solid electrolyte layer, respectively. Exemplary reactive gases include nitrogen, oxygen, gaseous hydrides, nitrogen oxides, H ₂ S, PH ₃ , and SO ₂ .

The term "inert gas" means the gas used to generate the plasma during the sputtering process. For this reason, blunt gas, especially argon, is often used, but bismuth and antimony are also used.

It is clear that the gas mixture of the at least one reactive gas used and the at least one inert gas can be varied. Thus, the composition of the deposited solid electrolyte layer is again affected. The at least one reactive gas may comprise oxygen and nitrogen. For example, during sputtering, an atmosphere containing 1 to 60% by volume of an inert gas, 1 to 60% by volume of oxygen, and 20 to 90% by volume of nitrogen may be used. It is preferably 10 to 40% by volume of an inert gas, 10 to 40% by volume of oxygen, and 40 to 80% by volume of nitrogen. More preferably, it is 15 to 30% by volume of an inert gas, 15 to 40% by volume of oxygen, and 40 to 70% by volume of nitrogen. The sum of the inert gas, oxygen and nitrogen is always 100% by volume.

The term "target" means a conductive evaporation material as a starting material. In the sputtering method, the target is often a cathode. However, individual components can also be added to the plasma via a gas stream and can also be deposited. Conductivity can be maintained, for example, by the addition of a conductive polymer and/or carbon (e.g., in the form of graphite) to the evaporation material. It is also conceivable to use a lithium salt in which an anion constitutes a conductive anion. It will be appreciated that the electrically conductive anion comprises an element present in the layer to be deposited or in the form of a gas after sputtering. For example, a conductive anion containing nitrogen and carbon can be used. Further, the target may comprise lithium nitrate, lithium phosphate, and/or lithium sulfate. The target can be prepared, for example, by hot pressing or cold pressing, or sintering, respectively.

Use the word "comprises/comprising" in this Within the scope of the invention are respectively referred to as open lists, and other components or steps are respectively permitted in addition to the components or treatments explicitly mentioned respectively.

The word "consists of/consisting of" refers to a closed list, respectively, within the scope of the invention, and does not include other components or steps, respectively, except for the components or treatments explicitly mentioned.

The term "substantially consists of/substantially consisting of" refers to a partially closed list, respectively, and indicates that, in addition to the components mentioned, may only include A component that constitutes a characteristic or a composition of other components that are present only in an amount that does not substantially alter the properties of the composition.

When used in the context of the present invention, the terms "comprises/comprising" are used to describe the composition, respectively, and the explicit indication includes compositions consisting of the components mentioned, or generally consisting of the components mentioned.

It will be understood that the features of the invention described above and the features to be explained hereinafter may be used not only in combination but also in various combinations independently without departing from the scope of the invention.

Other features and advantages of the present invention can be obtained from the description of the preferred embodiments and the drawings. The figure shows: Figure 1 is a SIMS (Secondary Ion Mass Spectrometry) inspection using LiPO-C as a target and DC sputtering using argon and nitrogen as processing gases; 2 is another SIMS inspection using a LiPO-C target and DC sputtering of argon, oxygen and nitrogen in different compositions; FIG. 3 is a block diagram representation of normalized ion conductivity for different program parameters; FIG. The discharge curve of the unit cell of the present invention; FIG. 5 is a charging and discharging curve of the unit cell according to FIG. 4; and FIG. 6 are other charging and discharging cycles of the unit cell according to FIGS. 3 and 4, respectively.

In one embodiment, the method according to the present invention comprises a reactive gas selected from at least one of nitrogen, oxygen, gaseous hydride, nitrogen oxides, H ₂ S, PH ₃ , and SO ₂ . In one embodiment, nitrogen and/or oxygen is used as the at least one reactive gas.

In an embodiment, the target according to the method of the invention comprises a material having electrical conductivity. The electrically conductive material comprises at least one or more selected from the group consisting of a conductive polymer and carbon.

In one embodiment, the carbon system is present in the form of graphite.

Carbon in the form of graphite is particularly suitable for producing electrical conductivity in the target due to its high electrical conductivity. In addition, graphite is characterized by high thermal conductivity. Thus, the graphite-containing target can be more easily evaporated. Alternatively, it is also possible to use other conductive carbon modifications. For example, a conductive single-walled carbon nanotube or a multi-walled carbon nanotube can be used. The latter itself is electrically conductive. When used in a target Good carbon nanotubes form good processing characteristics. However, care should be taken so that the conductive carbon nanotubes are not normally present in the deposited solid electrolyte layer. This can be ensured by using appropriate program parameters. Since a small amount of carbon is present in the layer of the present invention, it generally does not result in electrical conductivity within the layer, so that its mechanical properties can be improved, for example with respect to ductile yield. This is especially true for the layers of the invention comprising carbon nanotubes.

The conductive polymer may be selected from the group consisting of polyacetylene, polyfluorene, polyisothiophene One or more of polyphenylene, polyphenylenevinylene, polypyrrole, polyphenylene sulfide, polythiophene, poly(3-alkylthiophene), polyfuran, sulfonated polyaniline and polyaniline. The conductivity of the target can be adjusted by using a conductive polymer having a specific chain length. This can be particularly advantageous when using a hybrid form of the above-described sputtering method.

The conductive polymer can constitute a doped form. Different compounds can be used here. Examples of suitable dopants include protone acid.

The conductivity of the target can be, for example, at least 0.05 S/cm. Alternatively, the conductivity of the target is between 10 ^-3 and 0.1 S/cm, or between 10 ^-2 and 0.05 S/cm. The conductivity of the best system target is typically at least 10 ^-2 S/cm.

The LiPON or LiPSON solid electrolyte layer of the present invention is generally not electrically conductive, but only ion conductive. The solid electrolyte layer has a maximum conductivity of, for example, 10 ^-3 S/cm. More preferably, the maximum conductivity is less than 5.10 ^-4 S/cm, or less than 10 ^-4 S/cm, or less than 5.10 ^-5 S/cm, or less than 10 ^-5 S/cm, Or less than 10 ^-6 S/cm, or less than 10 ^-7 S/cm, or less than 10 ^-8 S/cm, or less than 10 ^-9 S/cm, or less than 10 ^-10 S/cm.

In one embodiment, the target comprises lithium phosphate and lithium sulfate. Thus, in particular, a LIPSON solid electrolyte layer, typically and in particular a LiP _x S _(1-x) ON solid electrolyte layer, wherein x < 1 can be realized.

In one embodiment, the target is comprised of 20 to 60% by weight of LiPO ₄ , 20 to 60% by weight of LiSO ₄ and 1 to 20% by weight of a conductive material. The sum of all percentages therein is 100% by weight. Preferably, it is an aliquot of lithium phosphate and lithium sulfate and a target having a different number of conductive polymers and/or carbon. For example, a target having 40% by weight of lithium phosphate and 40% by weight of lithium sulfate, a target of 45% by weight of lithium phosphate and 45% by weight of lithium sulfate, having 48% by weight of lithium phosphate and 48 is preferable. A target of wt% lithium sulfate, a target having 49% by weight of lithium phosphate and 49% by weight of lithium sulfate. Herein, the remainder consists of one or more parts selected from the group consisting of conductive polymers and carbon. Carbon is preferably used.

In one embodiment, the at least one substrate is selected from the group consisting of aluminum, tantalum, carbon, steel, polymers, glass, cathode materials, and anode materials. The substrate can be, for example, a metal, a dispersion, a semiconductor, a glass, a polymer, a foil material, or a composite formed from a mixture or laminate of the above materials. Preferably, the substrate is composed of aluminum or steel. The substrate has a layer thickness of substantially less than 1 mm. Preferred layer thicknesses are from 1 μm to 500 μm, or from 5 μm to 250 μm, or from 10 μm to 200 μm, or from 15 μm to 150 μm, or from 20 μm to 100 μm, or from 30 μm to 90 μm, or from 40 μm to 80 μm.

In one embodiment, the at least one inert gas system is selected A group of free He, Ne, and Ar.

According to a preferred embodiment, a LiPON or LiP _x S _(1-x) ON solid electrolyte layer is obtained according to the method of the present invention. Here, x<1. The stoichiometry of the solid electrolyte layer formed depends on the composition of the target or gas used. In addition, processing parameters affect the stoichiometry of the solid electrolyte layer formed. The LiPON solid electrolyte layer according to the present invention may exist in the form of a LiP _y ON solid electrolyte layer in which 0 < y < 1.2. Preferably, y is in the range of 0.1 to 1.1; or 0.2 to 1.0; or 0.3 to 0.9; or 0.4 to 0.8, or 0.5 to 0.6, respectively, or 0.7, respectively. With respect to the solid electrolyte layer LiP _x S _(1-x) ON according to the present invention, usually x < 1. Preferably, x is in the range of 0 < x < 0.7. More preferably, the x series is in the range of 0.1 to 0.6; or 0.15 to 0.55; or 0.2 to 0.5; or 0.25 to 0.45; or 0.3 to 0.4; or 0.32 to 0.38, or 0.34 to 0.36, respectively.

In one embodiment, one or more selected from the group consisting of substantially non-conductive polymers and C are contained in the LiPON or LiP _x S _(1-x) ON solid electrolyte layer. Clearly, the LiPON or LiP _x S _(1-x) ON solid electrolyte layers herein are generally not electrically conductive, but generally have only ionic conductivity. Therefore, for example, C may be present in the solid electrolyte layer in a suitable amount that does not substantially cause conductivity. This can be ensured, for example, by appropriate selection of program parameters. The presence of C can, for example, improve the properties of the solid electrolyte layer, such as fracture toughness. The non-conductive polymer can also be obtained by appropriately selecting the program parameters of the above-mentioned conductive polymer. The non-conductive polymer and/or C-system is uniformly distributed in the LiPON or LiP _x S _(1-x) ON solid electrolyte layer (where x < 1).

The amount of substantially non-conductive polymer and C and/or C in the LiPON or LiP _x S _(1-x) ON solid electrolyte layer (where x < 1) is less than 2% relative to the total weight of the solid electrolyte layer weight%. Preferably, the solid electrolyte layer is comprised between 10 ^-3 wt% and 2 wt%, preferably between 5.10 and ² wt% and 1 wt%, between 10 and ² wt% and 1 wt%. Between 10 and ² % by weight and 0.5% by weight of the substantially non-conductive polymer and/or C.

In one embodiment, the layer thickness of the LiPON or LiP _x S _(1-x) ON solid electrolyte layer is between about 1 μm and 4 μm.

In a preferred embodiment of the invention, a thin layer battery or electrochromic glass comprising the LiPON or LiP _x S _(1-x) ON solid electrolyte layer (where x < 1) is provided. Alternatively, a single or a plurality of unit cells including the thin layer battery of the LiPON or LiP _x S _(1-x) ON solid electrolyte layer (where x < 1) are also provided.

The thin layer battery is preferably composed of a plurality of unit cells each of which comprises a two-dimensional negative electrode and a two-dimensional positive electrode, and the solid electrolyte layer according to the present invention constitutes a separator interposed between the negative electrode and the positive electrode. Thin-layer batteries are used, for example, in conjunction with integrated electronic circuits or with micro-electromechanical systems (MEMS), sensors, and smart cards. As the negative electrode, for example, a metal in an elemental and/or partially oxidized form can be used. The elemental material comprises lithium, zinc, magnesium, iron, and mixtures thereof; also suitable for platinum, silver, titanium, or tantalum. Further, a lithium niobium alloy can be used as the anode. A composition of stoichiometric Li _(1+-x) Co _x O ₂ was used as a cathode material. These unit cells can be stacked to form a thin layer battery. Methods of preparing thin layer batteries are known to those skilled in the art. Preferably, a single unit cell is formed by a LiCoO ₂ layer and a Li layer with an intermediate LiPON or LiP _x S _(1-x) ON solid electrolyte layer (where x < 1).

The preparation of electrochromic glass or foil is known in the art. The glass or foil is separately provided with a functional layer compound. If the charge within the layer of the compound shifts (often caused by the application of an appropriate voltage), the optical properties of the compound change. Electrochromic thin layer unit cells are typically composed of two glass substrates with FTO (fluorinated tin oxide) or ITO (indium tin oxide) layers provided between the glass substrates. An electrochromic layer and an ion storage layer are disposed between the layers. They are again connected to an ion conducting layer that should have very little conductivity. For this reason, a LiPON or LiP _x S _(1-x) ON solid electrolyte layer (where x < 1) was found to be suitable.

The LiPON or LiP _x S _(1-x) ON solid electrolyte layer can also be used to manufacture thin layer batteries or electrochromic glass.

In a preferred embodiment of the invention, a target is provided for use in a sputtering process. The target comprises Li, P, O and a conductive material, wherein the conductive material is converted to an inert compound during sputtering. Furthermore, the target comprises N or S. The target may comprise one or more salts, wherein the compounds forming the ions of the salt are also deposited on the solid electrolyte layer or remain in the gas phase, respectively. Exemplary cations include lithium and ammonium ions. Suitable anions are especially phosphates, sulphuric acid and nitrates.

In one embodiment, the target comprises Li ₃ PO ₄ and Li ₂ SO ₄ .

In one embodiment, the target comprises 20 to 60% by weight of Li ₃ PO ₄ , 20 to 60% by weight of Li ₂ SO ₄ , and 1 to 20% by weight of the electrically conductive material. The sum of all percentages is 100% by weight.

It is to be understood that the above-described characteristics and the characteristics to be explained below are not limited to the individual combinations given, and may be applied in different combinations or independently without departing from the scope of the invention.

Hereinafter, the invention will be explained with reference to the examples and explained in more detail in the following description.

Example 1

For testing purposes, a disc shaped target having a diameter of 50 mm and a layer thickness of 7 mm was used. The target consists of lithium phosphate having from 1 to 10% by weight of carbon in the form of graphite. The target can be prepared by hot pressing or cold pressing, and sintering, respectively. The following sputtering procedure parameters were chosen: power density at the target > 8.5 W/cm ² ; pulsed DC (pulse DC) with duty cycle >95%; and program pressure 3.10 ^{- 2} mbar.

The compositional changes of the process gas allow adjustment of the following layer parameters: Carbon fraction

Ion conductivity

The shape of the layer.

The possible composition of the process gas is as follows:

Composition of 1:1 to 30% argon, 0% oxygen, 70% nitrogen

Composition 2: 2 to 25% argon, 15% oxygen, 60% nitrogen

Composition 3: 17% argon, 40% oxygen, 43% nitrogen.

Using secondary ion mass spectrometry, it can be shown that an increase in oxygen fraction reduces the concentration of carbon in the deposited layer, so that carbon is present in the process gas in the form of carbon monoxide or carbon dioxide, respectively, and is pumped together from the processing chamber. Remove (constant processing gas feed). The SIMS results of the obtained compositions 1 and 3 are shown in Figures 1 and 2, respectively. In the figures, a to h describe different ions, where a = Ni ^- , b = CH ^- , c = CN ₂ -, d = O ₂ -, e = Li ^- , f = C ^- , g = P ^- And h=CN ^- . In the region shown on the x-axis, region 10 represents Ni, 12 represents LiPON, 14 is transitioned from LiPON to Ni, and 16 represents Ni. Further, in Fig. 2, reference numeral 18 represents a polymer substrate to be used.

Ion conductivity is studied using impedance spectrometry measurements. Herein, the process gas mixing ratio has a considerable influence on the conductivity of the layer (see Figure 2). By varying the process gas mixture and the chamber pressure, the optimization between layer properties and deposition rate and layer morphology can be adjusted (see Figure 3). Thus, for composition 1 (Z 1 ), a substantially normal conductivity of from 0.3 to substantially 0.4 can be seen; composition 2 (Z 2 ) exhibits a normalized conductivity of substantially 0.41 to substantially 0.62; and composition 3 ( Z 3) has a normalized conductivity of substantially 0.35 to substantially 0.45.

It has been discovered that in addition to specific process examples, gas composition, process gas or chamber pressure, and sputtering power can vary over a wide range, affecting layer formation and characteristics.

In summary, it can be said that by using a suitable procedure parameter, when a target containing lithium carbon phosphate is used, a low carbon LiPON or LiP _x S _(1-x) ON electrolyte layer (where x < 1) can be deposited, respectively. Used as an electrolyte functional layer in thin-layer batteries. A special feature of a thin layer battery is that the electrolyte layer serves as an electrical separator between the anode and the cathode.

It has also been found that at least one of the distinct surfaces of the electrolyte boundary layer is felt-like. The LiPON or LiP _x S _(1-x) ON thin electrolyte layer of the present invention (where x < 1) is transparent in the visible light range and has stability against UV irradiation, except that it is not glassy. These characteristics show that in addition to the use of the solid electrolyte layer of the present invention, a thin layer battery may also be applied to the electrochromic glass.

Example 2

A 4 μm thick sputtered LiCoO ₂ layer tempered at 600 ° C for 4 hours was used as a cathode. The substrate was an aluminum foil having a thickness of 50 μm. On the cathode, a 3.2 μm thick LiPON layer according to the invention is deposited using the following program parameters: power density at the target > 8.5 W/cm ² ; pulsed DC with a duty cycle > 95% (pulse DC); and program pressure It is 3.10 ^-2 mbar. A mixture of 20% argon, 65% nitrogen, and 15% oxygen was used as the processing gas.

Herein, the LiPON layer has a constant layer thickness with any variation of less than 3%. A metal lithium anode is applied to the end of the stack of layers. At this end, a 3.2 μm thick Li layer was applied by thermal evaporation.

From Figure 4, it can be seen that the unit cell SSLB0121 shows a very characteristic discharge curve of the LCO cathode. The voltage flat zone is at 3.9V. And only deteriorates at the end of the discharge program.

In Fig. 5, it is shown that the unit cell according to the present invention is charged with a C/10 battery until a voltage of 4.2 V is reached. After that, it is charged in CV mode (ie, at 4.2V) until the battery drops to 1/3. The unit battery is discharged with a C/10 battery. The process depicted by i represents the amperage I (in amperes). The process depicted by j represents the voltage U (in volts).

The first cycle is measured with different measuring devices and is not shown here. The unit cell is partially charged, so the first charging step is only about 128 mAh/g. The reactions of further charging and discharging cycles can be seen from Figure 6, respectively.

In summary, the example according to the present invention shows that when an energy-saving DC sputtering method is used, when a carbon-containing LiPON target is used, in the case of partially or completely removing carbon in an oxygen-containing and nitrogen-containing argon atmosphere, it is high and uniform. A LiPON solid electrolyte layer is deposited at a deposition rate. The sputtered LiPON solid electrolyte layer can thus be used in thin layer unit cells or thin layer batteries, respectively. The preparation of the LiP _x S _(1-x) ON solid electrolyte layer (where x < 1) and its use in thin layer cells corresponds to the disclosed LiPON solid electrolyte layer and its use in thin layer batteries.

Claims (17)

A method of preparing a LiPON or LiPSON solid electrolyte layer, comprising: providing at least one substrate, at least one reactive gas, at least one inert gas, and a target; in an atmosphere comprising the at least one reactive gas and the at least one inert gas Internally sputtering; and forming the LiPON or LiPSON solid electrolyte layer on the at least one substrate, wherein the target comprises a conductive material, and the conductive material is converted into an inert compound during sputtering. The method of claim 1, wherein the at least one reactive gas comprises at least one or more selected from the group consisting of nitrogen, oxygen, gaseous hydrides, nitrogen oxides, H ₂ S, PH ₃ , and SO ₂ . The method of claim 2, wherein the at least one reactive gas system is configured as nitrogen and/or oxygen. The method of any of the preceding claims, wherein the electrically conductive material comprises at least one or more selected from the group consisting of a conductive polymer and C. The method of any of the preceding claims, wherein the C is present in the form of graphite. The method of claim 4, wherein the conductive polymer is selected from the group consisting of polyacetylene, polyazulene, and polyisothiophene. (polyisothionaphthene), polyphenylene, polyphenyl vinylene, polypyrrole, polyphenylene sulfide, polythiophene, poly(3-alkylthiophene), polyfuran, sulfonated polyaniline and One or more of polyanilines, wherein the conductive polymer is optionally doped. The method of any of the preceding claims, wherein the target comprises LiPO ₄ and LiSO ₄ . The method of claim 7, wherein the target is composed of 20 to 60% by weight of LiPO ₄ , 20 to 60% by weight of LiSO ₄ and 1 to 20% by weight of a conductive material. The method of any of the preceding claims, wherein the at least one substrate is selected from the group consisting of aluminum, tantalum, carbon, steel, polymers, glass, cathode materials, and anode materials. The method of any of the preceding claims, wherein the at least one inert gas system is selected from the group consisting of He, Ne, and Ar. A LiPON or LiP _x S _(1-x) ON solid electrolyte layer prepared by the method of any one of the preceding claims, wherein x < 1. A LiPON or LiP _x S _(1-x) ON solid electrolyte layer according to claim 11 wherein at least one or more selected from the group consisting of a non-conductive polymer and C is contained in LiPON or LiP _x S _{(1) -x)} ON in the solid electrolyte layer. The LiPON or LiP _x S _(1-x) ON solid electrolyte layer according to any one of claims 10 or 11, wherein the layer thickness of the LiPON or LiP _x S _(1-x) ON solid electrolyte layer is substantial The upper is between 1μm and 4μm. A thin layer battery, an electrochromic glass, or an electrochromic foil comprising the LiPON or LiP _x S _(1-x) ON solid electrolyte layer according to any one of claims 10 to 13. A target for a sputtering method comprising Li, P, O, and a conductive material, wherein the conductive material is converted to an inert compound during sputtering, and wherein the target further comprises N or S. A target of claim 15 wherein the target comprises LiPO ₄ , LiSO ₄ . The target material of claim 16, wherein the target comprises 20 to 60% by weight of LiPO ₄ , 20 to 60% by weight of LiSO ₄ and 1 to 20% by weight of a conductive material, and the sum of all the percentages thereof It is 100% by weight.