ELECTRICAL STORAGE SYSTEM COMPRISING A DISC-SHAPED DISCRETE ELEMENT, DISCRETE ELEMENT, METHOD FOR THE PRODUCTION THEREOF, AND USE THEREOF

Abstract

An electrical storage system is provided that has a thickness of less than 2 mm, which includes at least one sheet-type discrete element. The sheet-type discrete element exhibits high resistance against an attack of transition metals or transition metal ions, in particular titanium, wherein the sheet-type discrete element contains titanium. The invention also relates to a sheet-type discrete element for use in an electrical storage system, which exhibits high resistance to the attack of transition metals or of transition metal ions, in particular titanium.

Claims

1. A sheet-type discrete element comprising a composition, in wt %, of: SiO.sub.2 30 to 85 B.sub.2O.sub.3 3 to 20 Al.sub.2O.sub.3 0 to 15 Na.sub.2O 3 to 15 K.sub.2O 3 to 15 ZnO 0 to 12 TiO.sub.2 greater than or equal to 2 to 10, and CaO 0 to 0.1.

2. The sheet-type discrete element as claimed in claim 1, further comprising a thickness variation of not more than 25 μm based on wafer or substrate sizes in a range of >100 mm in diameter.

3. The sheet-type discrete element as claimed in claim 1, further comprising a thickness of less than 2 mm.

4. The sheet-type discrete element as claimed in claim 1, further comprising a thickness of not more than 100 μm.

5. The sheet-type discrete element as claimed in claim 1, further comprising a water vapor transmission rate (WVTR) of <10.sup.−3g/(m.sup.2.Math.d).

6. The sheet-type discrete element as claimed in claim 1, further comprising a specific electrical resistance at a temperature of 350° C. and at alternating current with a frequency of 50 Hz of greater than 1.0*10.sup.6 Ohm.Math.cm.

7. The sheet-type discrete element as claimed in claim 1, further comprising a maximum load temperature θ.sub.Max of at least 400° C.

8. The sheet-type discrete element as claimed in claim 1, further comprising a coefficient of linear thermal expansion a in a range from 2.0*10.sup.−6/K to 10*10.sup.−6/K.

9. The sheet-type discrete element as claimed in claim 1, further comprising a coefficient of linear thermal expansion a in a range from 3.0*10.sup.−6/K to 8.0*10.sup.−6/K.

10. The sheet-type discrete element as claimed in claim 1, comprising a product of maximum load temperature (θ.sub.Max) and a coefficient of linear thermal expansion (α) of 600.Math.10.sup.−6≦θ.sub.Maxα8000.Math.10.sup.−6.

11. The sheet-type discrete element as claimed in claim 1, comprising a product of maximum load temperature (θ.sub.Max) and a coefficient of linear thermal expansion (α) of 800.Math.10.sup.−6≦θ.sub.Max.Math.α5000.Math.10.sup.−6.

12. The sheet-type discrete element as claimed in claim 1, further comprising at least one surface that is inert and/or permeable to a reduced degree and/or impermeable with respect to materials coming into contact with the at least one surface.

13. The sheet-type discrete element as claimed in claim 12, wherein the at least one surface is designed as a barrier layer.

14. The sheet-type discrete element as claimed in claim 13, wherein the barrier layer is a barrier against a diffusion of metals.

15. The sheet-type discrete element as claimed in claim 13, wherein the barrier layer is a barrier against a diffusion of transition metals.

16. The sheet-type discrete element as claimed in claim 13, wherein the barrier layer is formed by doping or overdoping with at least one alkali metal and/or transition metals.

17. The sheet-type discrete element as claimed in claim 1, wherein the composition is a glass.

18. The sheet-type discrete element as claimed in claim 1, wherein the sheet-type discrete element is configured for a use elected from the group consisting of a substrate in an electrical storage system, a superstrate in an electrical storage system, and a cover in an electrical storage system.

19. A method for producing a sheet-type discrete element for use in an electrical storage system, comprising: melting a composition, in wt %, of: SiO.sub.2 30 to 85, B.sub.2O.sub.3 3 to 20, Al.sub.2O.sub.3 0 to 15, Na.sub.2O 3 to 15, K.sub.2O 3 to 15, ZnO 0 to 12, TiO.sub.2 greater than or equal to 2 to 10, and CaO 0 to 0.1; and subsequently hot shaping the composition.

20. The method as claimed in claim 19, wherein the hot shaping comprises drawing.

21. An electrical storage system, comprising: at least one sheet-type discrete element having a thickness of less than 2 mm and a composition, in wt %, of: SiO.sub.2 30 to 85, B.sub.2O.sub.3 3 to 20, Al.sub.2O.sub.3 0 to 15, Na.sub.2O 3 to 15, K.sub.2O 3 to 15, ZnO 0 to 12, TiO.sub.2 greater than or equal to 2 to 10, and CaO 0 to 0.1, wherein the at least one sheet-type discrete element exhibits high resistance against an attack of transition metals or transition metal ions, and wherein the sheet-type discrete element contains titanium.

22. The electrical storage system as claimed in claim 21, wherein the transition metals or transition metal ions comprises titanium or titanium ions.

23. The electrical storage system as claimed in claim 21, further comprising at least one surface of the at least one sheet-type discrete element is inert and/or permeable to a reduced degree and/or impermeable to materials coming into contact with the at least one surface.

24. The electrical storage system as claimed in claim 23, wherein the at least one surface is a barrier layer.

25. The electrical storage system as claimed in claim 24, wherein the barrier layer is a barrier against a diffusion of metals.

26. The electrical storage system as claimed in claim 24, wherein the barrier layer is a barrier against a diffusion of transition metals.

27. The electrical storage system as claimed in claim 24, wherein the barrier layer is formed by doping or overdoping with at least one alkali metal and/or a transition metal.

28. The electrical storage system as claimed in claim 24, wherein the barrier layer is a barrier against a diffusion of titanium and/or titanium ions.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0105] FIG. 1 shows a diagram illustrating the penetration depth of metallic and ionic titanium as a function of the TiO.sub.2 content of the sheet-type discrete element;

[0106] FIG. 2 is a schematic view of an electrical storage element; and

[0107] FIG. 3 is a schematic view of a sheet-type discrete element.

DETAILED DESCRIPTION

[0108] FIG. 1 shows a diagram for illustrating the influence of the TiO.sub.2 content of the sheet-type discrete element on the diffusion of metallic titanium and ionic titanium. The penetration depth of titanium is shown in arbitrary units (arb.u.) in each case, at the left for metallic titanium, at the right for ionic titanium. The composition of the sheet-type discrete elements corresponds to Exemplary Embodiment 4 and to Comparative Example 3, respectively, of table 1. The two examples differ in that Comparative Example 3 does not contain TiO.sub.2, in contrast to Exemplary Embodiment 4. With regard to titanium diffusion, the penetration depth in the titanium-containing sheet-type discrete element is significantly reduced, for both the case of metallic exposure and for the ionic exposure to TiO.sub.2.

[0109] FIG. 2 schematically shows an electrical storage system 1 according to the present invention. It comprises a sheet-type discrete element 2 which is used as a substrate. A sequence of different layers is applied on the substrate. By way of example and without being limited to the present example, first the two collector layers are applied on the sheet-type 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 battery 1 comprises an encapsulation layer 8.

[0110] In the context of the present invention, any material which is capable of preventing or greatly reducing 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.

[0111] FIG. 3 schematically illustrates a sheet-type discrete element according to the present invention, here in the form of a sheet-type shaped body 10. In the context of the present invention, a shaped body is referred to as being of sheet type 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.

LIST OF REFERENCE NUMERALS

[0112] 1 Electrical storage system

[0113] 2 Sheet-type discrete element used as a substrate

[0114] 3 Cathode collector layer

[0115] 4 Anode collector layer

[0116] 5 Cathode

[0117] 6 Electrolyte

[0118] 7 Anode

[0119] 8 Encapsulation layer

[0120] 10 Sheet-type discrete element in the form of a sheet-type shaped body