USE OF AN AIR-STABLE SOLID ELECTROLYTE

Abstract

An air-stable solid electrolyte may be used as a coating for a battery component of a battery cell.

Claims

1. A coating for a battery component of a battery cell, comprising an air-stable solid electrolyte.

2. The coating according to claim 1, wherein the battery cell is a solid-state cell.

3. The coating according to claim 1, wherein the solid electrolyte has an ionic conductivity of greater than 10.sup.−4 S/cm, in particular greater than 10.sup.−3 S/cm.

4. The coating according to claim 1, wherein the solid electrolyte is selected from the group consisting of: Li.sub.3InCl.sub.6, Li.sub.3InBr.sub.6, Li.sub.3YX.sub.6, where X represents Cl, Br, or I, Li.sub.3ErX.sub.6, where X represents Cl, Br, or I, Li.sub.3ScX.sub.6, where X represents Cl, Br, or I, Li.sub.3LaI.sub.6, Li.sub.3LuCl.sub.6, Li.sub.3−xEr.sub.1−xZr.sub.xCl.sub.6, where x≤0.6, Li.sub.3−xY.sub.1−xZr.sub.xCl.sub.6, where x≤0.6, Li.sub.3Y.sub.1−xIn.sub.xCl.sub.6, where 0≤x<1, and Li.sub.xScCl.sub.3+x, where 0≤x≤5.

5. The coating according to claim 1, wherein the battery component is coated before cell production of the battery cell.

6. A battery component of a battery cell, having at least one coating made of an air-stable solid electrolyte.

7. The battery component according to claim 6, wherein the coating has a layer thickness of between 10 nm and 1,000 nm.

8. A battery cell having a battery component according to claim 6.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0028] Embodiments of the invention are explained in more detail below with reference to the drawings, shown in schematic and simplified representations, in which:

[0029] FIG. 1 shows a solid-state battery,

[0030] FIG. 2 shows a coating of a cathode material,

[0031] FIG. 3 shows a coating of a conductive additive,

[0032] FIG. 4 shows a coating of a solid electrolyte, and

[0033] FIG. 5 shows a method for coating a composite cathode.

[0034] Corresponding parts and dimensions are always provided with the same reference signs in all figures.

DETAILED DESCRIPTION OF THE INVENTION

[0035] FIG. 1 shows a solid-state battery 2 for an electrically driven or drivable motor vehicle, for example an electric or hybrid vehicle. The solid-state battery 2 has a battery housing 4 and at least one battery cell 6 accommodated therein. The battery cell 6, also referred to below as a solid-state cell, has a number of battery components 8, 10, 12, 14, 16, 18. The battery component 8 is an anode layer forming the anode of the battery cell 6, the battery component 10 being a separator layer. The battery component 12 is a composite cathode of the solid-state cell 6 made of a composite material containing the battery components 14, 16 and 18.

[0036] In this case, the battery component 14 is a cathode material, the battery component 16 is a conductive additive, and the battery component 18 is a solid electrolyte as an ionic conductive additive. The battery component 12 or one or each battery component 14, 16, 18 have a low or reduced stability to air or moisture. In other words, the battery components 12, 14, 16, 18 have a comparatively high sensitivity to air or moisture.

[0037] To protect these battery components 12, 14, 16, 18, one or more of these components is coated with an air-stable solid electrolyte 20 (FIGS. 2 to 4).

[0038] FIG. 2 shows a coating of the cathode material 14. The cathode material 14 is, for example, NMC, in particular NMC 811, and in particular has a high Ni content. The coating of the active cathode material 14 with the air-stable solid electrolyte 20 protects the cathode material 14 from chemical reaction with air and allows the cathode material 14 to be handled in a normal atmosphere.

[0039] FIG. 4 shows a coating of the solid electrolyte 18. The solid electrolyte 18 is designed in particular as a sulfide solid electrolyte. The coating of the surface of the solid electrolyte 18 with an air-stable solid electrolyte 20 improves the air stability of the sulfide solid electrolyte 18 and prevents the release of hydrogen sulfide into the air.

[0040] FIG. 3 shows a coating of the conductive additive 16. In this case, for example, carbon-based conductive particles, for example carbon fibers, are provided as the conductive additive 16. The coating of carbon with the air-stable solid electrolyte 20 reduces unwanted secondary reactions at the interfaces between the carbon-based conductive additive 16 and the sulfide solid electrolyte 18.

[0041] The coating(s) can be carried out in a protective atmosphere, for example in a glove box. For example, atomic layer deposition, sol-gel, or spray drying, etc., can be used as coating methods. After the coating process, it is possible to carry out the subsequent cell assembly in air having a low dew point (e.g., −10° C.), or even in a normal atmosphere. The resulting protective layer or coating is indicated by the reference sign 22 in the figures.

[0042] The air-stable solid electrolyte 20 of the coating 22 has an ionic conductivity of greater than 10.sup.−4 S/cm, in particular greater than 10.sup.−3 S/cm. In this case, the coating 22 has a layer thickness of between 10 nm and 1,000 nm, for example. The air-stable solid electrolyte 20 is, for example, a chloride-based solid electrolyte. In particular, the solid electrolyte 20 is a material selected from a group formed by lithium-indium chloride (Li.sub.3InCl.sub.6), lithium-indium bromide (Li.sub.3InBr.sub.6), a lithium-lanthanum iodide (Li.sub.3LaI.sub.6), a lithium-lutetium chloride (Li.sub.3LuCl.sub.6), or a lithium-conducting rare-earth halide of the form Li.sub.3MX.sub.6, where M represents either yttrium Y, erbium Er or scandium Sc, and where X represents either chlorine Cl, bromine Br, or iodine I, or of the form Li.sub.3−xM.sub.1−xZr.sub.xCl.sub.6 (where x≤0.6 and where M represents either Er or Y), or of the form Li.sub.3Y.sub.1−xIn.sub.xCl.sub.6 (where 0≤x<1), or of the form Li.sub.xScCl.sub.3+x (where 0≤x≤5, in particular 1≤x≤5).

[0043] In the embodiment of FIG. 2-4, the battery components 14, 16, 18 are preferably coated before the composite cathode 12 is produced. FIG. 5 shows an alternative embodiment in which the composite cathode 12 is produced first and then coated with the solid electrolyte 20. In this case, the composite cathode has, for example, a porosity of 40% so that a solution with the solid electrolyte 20 can substantially completely penetrate or infiltrate the composite material and thus coat it.

[0044] The claimed invention is not restricted to the embodiments described above. Rather, other variants of the invention can also be derived therefrom by a person skilled in the art within the scope of the disclosed claims without departing from the subject matter of the claimed invention. In particular, all of the individual features described in connection with the different embodiments can also be combined in other ways within the scope of the disclosed claims without departing from the subject matter of the claimed invention.

LIST OF REFERENCE SIGNS

[0045] 2 Solid-state battery

[0046] 4 Battery housing

[0047] 6 Solid-state cell/battery cell

[0048] 8 Battery component/anode layer

[0049] 10 Battery component/separator layer

[0050] 12 Battery component/composite cathode

[0051] 14 Battery component/cathode material

[0052] 16 Battery component/conductive additive

[0053] 18 Battery component/solid electrolyte

[0054] 20 Solid electrolyte

[0055] 22 Coating