Electrical storage system with a sheet-like discrete element, sheet-like discrete element, method for producing same, and use thereof

Abstract

An electrical storage system is provided that has a thickness of less than 2 mm and includes comprises at least one sheet-like discrete element. At least one surface of the at least one sheet-like discrete element is designed to be chemically reactive to a reduced degree, inert, and/or permeable to a reduced degree, and/or impermeable with respect to materials coming into contact with the surface. Also provided are a sheet-like discrete element and to the production and use thereof.

Claims

1. An electrical storage system, comprising: a thickness of less than 2 mm; a sheet-like discrete element made of glass; a barrier layer on a surface of the sheet-like discrete element, the barrier layer being permeable to a reduced degree with respect to lithium coming into contact with the surface, wherein the barrier layer comprises an element selected from the group consisting of a nitride of Si, oxide of Si, carbide of Si, nitride of Al, nitride of Cr, nitride of Ti, nitride of Zr, nitride of Hf, nitride of Ta, oxide of Al, oxide of Cr, oxide of Ti, oxide of Zr, oxide of Hf, oxide of Ta, and any combinations thereof, and an anode, a cathode, and an electrolyte on the barrier layer, wherein the glass is selected from any of the following composition ranges, in wt %: TABLE-US-00039 No. 1 No. 2 No. 3 No. 4 No. 5 SiO.sub.2 30-85 58-65 64-74 75-85 50-65 B.sub.2O.sub.3 3-20 6-10.5 8-18 0-6 Al.sub.2O.sub.3 0-15 14-25 0.5-4.5 15-20 Li.sub.2O 0-6 Na.sub.2O 3-15 6-10 1.5-5.5 8-15 K.sub.2O 3-15 6-10 0-2 0-5 MgO 0-3 0-5 CaO 0-0.1 0-9 5-9 0-7 BaO 3-8 0-4 0-4 ZnO 0-12 0-2 2-6 0-4 TiO.sub.2 0.5-10.sup. 0-2 0-1 MgO + CaO + .sup.8-18. BaO

2. The electrical storage system as claimed in claim 1, wherein the glass further comprises from 0 to 1 wt % of refining agents selected from the group consisting of SnO.sub.2, CeO.sub.2, As.sub.2O.sub.3, Cl.sup., F.sup., and sulfates.

3. The electrical storage system as claimed in claim 1, wherein the barrier layer comprises a vertical composition variation of the surface so as to provide no direct diffusion paths into the sheet-like discrete element.

4. The electrical storage system as claimed in claim 3, wherein the vertical composition variation comprises getter materials for alkali and/or alkaline earth metals.

5. The electrical storage system as claimed in claim 3, wherein the vertical composition variation comprises a sequence of at least adjacent layers having a different composition.

6. The electrical storage system as claimed in claim 1, wherein the barrier layer is a plasma-assisted coating or an atomic layer deposition (ALD) coating.

7. The electrical storage system as claimed in claim 1, wherein the barrier layer has a barrier effect initiated by a separate annealing step prior to application of a current conductor or the anode.

8. The electrical storage system as claimed in claim 1, wherein the barrier layer has a barrier effect initiated during annealing of the anode.

9. The electrical storage system as claimed in claim 1, wherein the sheet-like discrete element comprises a substrate having a transmittance selected from the group consisting of: 0.1% or more in a range from 200 nm to 270 nm at a thickness of 30 m; more than 0.5% at 222 nm at a thickness of 30 m; more than 0.3% at 248 nm at a thickness of 30 m; more than 3% in at 282 nm at a thickness of 30 m; more than 50% at 308 nm at a thickness of 30 m; more than 88% at 351 nm at a thickness of 30 m; 0.1% or more in a range from 200 nm to 270 nm at a thickness of 100 m; more than 0.5% at 222 nm at a thickness of 100 m; more than 0.3% at 248 nm at a thickness of 100 m; more than 0.1% at 282 nm at a thickness of 100 m; more than 30% at 308 nm at a thickness of 100 m; and more than 88% at 351 nm at a thickness of 100 m.

10. The electrical storage system as claimed in claim 1, wherein the sheet-like discrete element has transmittance values that, due to the barrier layer, are reduced by less than 60%.

11. The electrical storage system as claimed in claim 1, wherein the barrier coating is amorphous.

12. The electrical storage system as claimed in claim 1, wherein the sheet-like discrete element has thickness variation of not more than 25 m based on a wafer size in a range of >100 mm in diameter.

13. The electrical storage system as claimed in claim 1, wherein the sheet-like discrete element has a water vapor transmission rate (WVTR) of <10.sup.3g/(m.sup.2.Math.d).

14. The electrical storage system as claimed in claim 1, wherein the sheet-like discrete element has a thickness selected from the group consisting of less than 2 mm, less than 1 mm, less than 500 m, less than or equal to 200 m, and not more than 100 m.

15. The electrical storage system as claimed in claim 1, wherein the sheet-like discrete element has a property selected from the group consisting of: a specific electrical resistance at a temperature of 350 C. and at an alternating current with a frequency of 50 Hz of greater than 1.0*10.sup.6 Ohm.Math.cm, a maximum load temperature .sub.Max of at least 300 C., a coefficient of linear thermal expansion in a range from 2.0*10.sup.6/K to 10*10.sup.6/K, a relationship of a product of the maximum load temperature .sub.Max and the coefficient of linear thermal expansion of: 600.Math.10.sup.6.sub.Max.Math.<8000.Math.10.sup.6, and combinations thereof.

16. A sheet-like discrete element made of glass for use in an electrical storage system, comprising: a glass substrate having a surface; and a barrier layer on the surface, the barrier layer being a barrier against the diffusion of lithium, wherein the barrier layer wherein the barrier layer comprises an element selected from the group consisting of a nitride of Si, oxide of Si, carbide of Si, nitride of Al, nitride of Cr, nitride of Ti, nitride of Zr, nitride of Hf, nitride of Ta, oxide of Al, oxide of Cr, oxide of Ti, oxide of Zr, oxide of Hf, oxide of Ta, and any combinations thereof, wherein the barrier layer provides to direct diffusion paths into the glass, and wherein the glass substrate comprises glass is selected from any of the following composition ranges, in wt %: TABLE-US-00040 No. 1 No. 2 No. 3 No. 4 No. 5 SiO.sub.2 30-85 58-65 64-74 75-85 50-65 B.sub.2O.sub.3 3-20 6-10.5 8-18 0-6 Al.sub.2O.sub.3 0-15 14-25 0.5-4.5 15-20 Li.sub.2O 0-6 Na.sub.2O 3-15 6-10 1.5-5.5 8-15 K.sub.2O 3-15 6-10 0-2 0-5 MgO 0-3 0-5 CaO 0-0.1 0-9 5-9 0-7 BaO 3-8 0-4 0-4 ZnO 0-12 0-2 2-6 0-4 TiO.sub.2 0.5-10.sup. 0-2 0-1 MgO + CaO + .sup.8-18. BaO

17. The sheet-like discrete element as claimed in claim 16, wherein the glass further comprises from 0 to 1 wt % of refining agents selected from the group consisting of SnO.sub.2, CeO.sub.2, As.sub.2O.sub.3, Cl.sup., F.sup., and sulfates.

18. The sheet-like discrete element as claimed in claim 16, wherein the barrier layer comprises a vertical composition variation so as to provide no direct diffusion paths into the glass.

19. The sheet-like discrete element as claimed in claim 18, wherein the composition includes getter materials for alkali and/or alkaline earth metals.

20. The sheet-like discrete element as claimed in claim 16, wherein the composition is varied vertically by comprising a sequence of at least two layers having a different composition.

21. The sheet-like discrete element as claimed in claims 16, wherein the barrier layer is a plasma-assisted layer or an atomic layer deposition (ALD) layer.

22. The sheet-like discrete element as claimed in claim 16, wherein the glass substrate has a transmittance selected from the group consisting of: 0.1% or more in a range from 200 nm to 270 nm at a thickness of 30 m; more than 0.5% at 222 nm at a thickness of 30 m; more than 0.3% at 248 nm at a thickness of 30 m; more than 3% in at 282 nm at a thickness of 30 m; more than 50% at 308 nm at a thickness of 30 m; more than 88% at 351 nm at a thickness of 30 m; 0. 1% or more in a range from 200 nm to 270 nm at a thickness of 100 m; more than 0.5 % at 222 nm at a thickness of 100 m; more than 0.3% at 248 nm at a thickness of 100 m; more than 0.1% at 282 nm at a thickness of 100 m; more than 30% at 308 nm at a thickness of 100 m; and more than 88% at 351 nm at a thickness of 100 m.

23. The sheet-like discrete element as claimed in claim 16, wherein the sheet-like discrete element has transmittance values that, due to the barrier layer, are reduced relative to those of the glass substrate by less than 60%.

24. The sheet-like discrete element as claimed in claims 16, wherein the barrier layer is amorphous.

25. The sheet-like discrete element as claimed in claim 16, wherein the glass substrate has a thickness variation of not more than 25 m based on wafer or substrate sizes in a range of >100 mm in diameter.

26. The sheet-like discrete element as claimed in claim 16, wherein the glass substrate has a thickness selected from the group consisting of less than 2 mm, less than 1 mm, less than 500 m, less than or equal to 200 m, and not more than 100 m.

27. The sheet-like discrete element as claimed in claim 16, further comprising a property selected from the group consisting of a water vapor transmission rate (WVTR) of <10.sup.3g/(m.sup.2.Math.d), a specific electrical resistance at a temperature of 350 C. and at an alternating current with a frequency of 50 Hz of greater than 1.0*10.sup.6 Ohm.Math.cm, a maximum load temperature .sub.Max of at least 300 C., a coefficient of linear thermal expansion a in a range from 2.0*10.sup.6/K to 10*10.sup.6/K, a relationship of a product of the maximum load temperature .sub.Max and the coefficient of linear thermal expansion of: 600.Math.10.sup.6<.sub.Max.Math.<8000.Math.10.sup.6, and combinations thereof.

28. A sheet-like discrete element made of glass for use in an electrical storage system, comprising: a glass substrate having a surface; and a barrier layer on the surface, the barrier layer being a barrier against the diffusion of lithium and comprising Si.sub.3N.sub.4, wherein the glass substrate comprises glass is selected from any of the following composition ranges, in wt %: TABLE-US-00041 No. 1 No. 2 No. 3 No. 4 No. 5 SiO.sub.2 30-85 58-65 64-74 75-85 50-65 B.sub.2O.sub.3 3-20 6-10.5 8-18 0-6 Al.sub.2O.sub.3 0-15 14-25 0.5-4.5 15-20 Li.sub.2O 0-6 Na.sub.2O 3-15 6-10 1.5-5.5 8-15 K.sub.2O 3-15 6-10 0-2 0-5 MgO 0-3 0-5 CaO 0-0.1 0-9 5-9 0-7 BaO 3-8 0-4 0-4 ZnO 0-12 0-2 2-6 0-4 TiO.sub.2 0.5-10 0-2 0-1 MgO + CaO + BaO 8-18.

29. The sheet-like discrete element as claimed in claim 28, wherein the barrier is a PICVD layer.

30. The sheet-like discrete element as claimed in claim 28, wherein the barrier is an MF sputtered layer.

Description

DESCRIPTION OF THE DRAWINGS

(1) FIG. 1 schematically illustrates an electrical storage system which includes at least one sheet-like discrete element.

(2) FIG. 2 schematically illustrates a sheet-like discrete element according to the invention.

(3) FIGS. 3 to 6 show ToF-SIMS spectra of different sheet-like discrete elements.

DETAILED DESCRIPTION

(4) FIG. 1 schematically shows an electrical storage system 1 according to the present invention. It comprises a sheet-like discrete element 2 which is used as a substrate. Furthermore, a layer is applied to the substrate 2 which is designed as a diffusion barrier against metals, preferably against alkali and/or alkaline earth metals or ions of these metals. The coating 21 according to the invention is an oxide, nitride and/or a carbide and furthermore includes at least one of the elements Si, Al, Cr, Ta, Zr, Hf, and/or Ti. Furthermore, a sequence of different layers is applied on the substrate 2 or, more specifically, the barrier layer 21. By way of example and without being limited to the present example, first the two collector layers are applied on the sheet-like discrete element 2, cathode collector layer 3, and anode collector layer 4. Such collector layers usually have a thickness of a few micrometers and are made of a metal, for example of copper, aluminum, or titanium. Superimposed on collector layer 3 is cathode layer 5. If the electrical storage system 1 is a lithium-based thin film battery, the cathode is made of a lithium-transition metal compound, preferably an oxide, for example of LiCoO.sub.2, of LiMnO.sub.2, or else of LiFePO.sub.4. Furthermore, the electrolyte 6 is applied on the substrate and is at least partially overlapping cathode layer 5. In the case of a lithium-based thin film battery, this electrolyte is mostly LiPON, a compound of lithium with oxygen, phosphorus, and nitrogen. Furthermore, the electrical storage system 1 comprises an anode 7 which may for instance be made of lithium titanium oxide or else of metallic lithium. Anode layer 7 is at least partially overlapping electrolyte layer 6 and collector layer 4. Furthermore, the electrical storage system 1 comprises an encapsulation layer 8.

(5) In the context of the present invention, any material which prevents or greatly reduces the attack of fluids or other corrosive materials on the electrical storage system 1 is considered as an encapsulation or sealing of the electrical storage system 1.

(6) FIG. 2 schematically illustrates a sheet-like discrete element according to the present invention, here in the form of a sheet-like shaped body 10. In the context of the present invention, a shaped body is referred to as being sheet-like or a sheet if its dimension in one spatial direction is not more than half of that in the two other spatial directions. A shaped body is referred to as a ribbon in the present invention if it has a length, width, and thickness for which the following relationship applies: the length is at least ten times larger than the width which in turn is at least twice as large as the thickness. Furthermore, a layer is applied on the sheet-like discrete element 10, which is designed as a diffusion barrier against metals, preferably against alkali and/or alkaline earth metals or ions of these metals. The coating 101 according to the invention is an oxide, a nitride, and/or a carbide and furthermore includes at least one of the elements Si, Al, Cr, Ta, Zr, Hf, and/or Ti.

(7) FIG. 3 shows the ToF-SIMS spectrum of a non-coated sheet-like discrete element, the sheet-like discrete element consisting of the glass D263. The spectrum was obtained after the sample had been stored in liquid LiNO.sub.3 for 10 minutes at 380 C. Lithium is clearly detectable, with a (dimensionless) signal of approximately 5*10.

(8) FIG. 4 shows a ToF-SIMS spectrum of a sheet-like discrete element, for which a substrate consisting of the glass D263 with an SiO.sub.2 barrier layer of a layer thickness of approximately 100 nm obtained by magnetron sputtering (MF sputtering) was examined after having been stored in liquid LiNO.sub.3. The spectrum was obtained after the sample had been stored in liquid LiNO.sub.3 for 10 minutes at 380 C. Lithium is clearly detectable both in the SiO.sub.2 layer and in the substrate material. Compared to the reference shown in FIG. 1, the level of the lithium signal in the substrate material has only been reduced to half. Thus, there is no sufficient barrier effect.

(9) FIG. 5 shows the ToF-SIMS spectrum of a sheet-like discrete element, for which a substrate consisting of the glass D263 with an Si.sub.3N.sub.4 barrier layer of a layer thickness of approximately 100 nm obtained by magnetron sputtering (MF sputtering) was examined after having been stored in liquid LiNO.sub.3. The spectrum was obtained after the sample had been stored in liquid LiNO.sub.3 for 10 minutes at 380 C. Lithium is not detectable within the barrier layer. In the glass the signal is reduced by a factor of about 5000 compared to the reference shown in FIG. 1. This weak signal might as well indicate a contamination of the glass with lithium as a trace element. Thus, the coating shown here is a very good barrier against diffusion of lithium ions.

(10) FIG. 6 shows the ToF-SIMS spectrum of a sheet-like discrete element, for which a substrate consisting of the glass D263 with an Si.sub.3N.sub.4 barrier layer having a layer thickness of approximately 100 nm obtained by Plasma Impulse Chemical Vapor Deposition (PICVD) was examined after having been stored in liquid LiNO.sub.3. The spectrum was obtained after the sample had been stored in liquid LiNO.sub.3 for 10 minutes at 380 C. Lithium is detectable in the barrier layer with a concentration decreasing towards the glass substrate. In the glass the signal is reduced by a factor of about 500 compared to the reference shown in FIG. 1. The barrier effect of the layer can be sufficient under certain circumstances.

LIST OF REFERENCE NUMERALS

(11) 1 Electrical storage system 2 Sheet-like discrete element used as a substrate 21 Diffusion barrier layer on substrate 3 Cathode collector layer 4 Anode collector layer 5 Cathode 6 Electrolyte 7 Anode 8 Encapsulation layer 10 Sheet-like discrete element in the form of a sheet-like shaped body 101 Diffusion barrier layer on sheet-like discrete element