ENERGY ACCUMULATOR AND MOTOR VEHICLE

Abstract

An energy accumulator, in particular for a motor vehicle, has a secondary cell with two complementary electrodes, a separator spacing them apart, a cell housing which encloses the electrodes and the separator, and an electrolyte with which the cell housing is filled. In addition, hollow glass spheres are located within the cell housing, which are filled with a quantity of the electrolyte and/or an additive and which are in contact with the electrolyte accommodated in the cell housing.

Claims

1. An energy accumulator for a motor vehicle, comprising: a secondary cell with two complementary electrodes, a separator configured to space apart the complementary electrodes, a cell housing which encloses the complementary electrodes and the separator, an electrolyte with which the cell housing is filled, and at least two hollow glass spheres located within the cell housing, which hollow glass spheres are filled with a quantity of the electrolyte and/or an additive and which are in contact with the electrolyte accommodated in the cell housing.

2. The energy accumulator according to claim 1, wherein one wall of the hollow glass spheres is formed exclusively by a glass.

3. The energy accumulator according to claim 1, wherein the glass of the hollow glass spheres is selected such that it is dissolved by a chemical reaction with the electrolyte, in particular wherein the glass used is a silicate glass, an aluminosilicate glass, a phosphorus silicate glass, a phosphate glass, a borate glass and/or a borosilicate glass.

4. The energy accumulator according to claim 3, wherein the wall of the hollow glass spheres is designed such that the wall is only partially dissolved by the chemical reaction, whereby a residual structure, which runs through the soluble components of the hollow glass spheres in the initial state, is retained after the soluble components have been dissolved.

5. The energy accumulator according to claim 3, wherein a duration of dissolution of the hollow glass spheres is predetermined by a selection of the wall thickness of the wall.

6. The energy accumulator according to claim 5, wherein hollow glass spheres with different wall thicknesses and/or different diameters are used.

7. The energy accumulator according to claim 5, wherein the hollow glass spheres have wall thicknesses in the range between 1 nanometer and 30 micrometers.

8. The energy accumulator according to claim 5, wherein the hollow glass spheres have wall thicknesses in the range between 5 nanometers and 5 micrometers.

9. The energy accumulator according to claim 3, wherein the glass is a silicate glass, an aluminosilicate glass, a phosphorus silicate glass, a phosphate glass, a borate glass and/or a borosilicate glass.

10. The energy accumulator according to claim 1, wherein the hollow glass spheres are accommodated in a coating of the separator and/or at least one inactive component of the secondary cell.

11. The energy accumulator according to claim 10, wherein the inactive component is a wall of the cell housing and/or a portion of a current collector of the electrodes.

12. A motor vehicle having an energy accumulator according to claim 1.

Description

BRIEF DESCRIPTION OF THE DRAWINGS

[0029] In the following, embodiments of the invention are described in more detail with reference to the drawings, in which:

[0030] FIG. 1 shows a schematic representation of a motor vehicle driven by an electric motor having an energy accumulator; and

[0031] FIG. 2 is a schematic partial sectional view of a secondary cell of the energy accumulator of the motor vehicle.

[0032] Corresponding parts are in all figures always denoted with the same reference signs.

DETAILED DESCRIPTION OF THE INVENTION

[0033] In FIG. 1, a motor vehicle 1 is shown schematically. This motor vehicle 1 is a land-based, wheel-bound vehicle, specifically a passenger car. The motor vehicle 1 is driven by an electric motor and for this purpose has an electric motor 2 and a traction battery 4. The traction battery 4 in turn has a plurality of, in particular four, battery modules 6 which in turn have a multiplicity of secondary cells 8 (see FIG. 2). The traction battery 4 thus represents the energy accumulator of the motor vehicle 1.

[0034] Each secondary cell 8 has a cell housing (in short: housing 10) in which a number of paired electrodes 12 is arranged within an electrolyte solution 14, also called “electrolyte” for short. In the present embodiment, only one pair of electrodes 12 is shown. The secondary cell 8 also has a separator 16 which is arranged between the two electrodes 12 and spatially separates them from one another. In addition, a contact lug 18 (also called a “current collector”) guided out of the housing 10 in a media-tight manner is also connected to each electrode 12.

[0035] In order to delay aging of the secondary cell 8 due to the consumption of lithium ions, each secondary cell 8 has a reservoir which is used for the delayed release of electrolyte. The reservoir is formed by a multiplicity of hollow glass spheres 20 which have enclosed in their interior a quantity of the electrolyte solution 14. The hollow glass spheres 20 are arranged in the secondary cell 8 such that the hollow glass spheres 20 are constantly in contact with the “free” electrolyte solution 14 accommodated in the housing 10. As a result, the glass of the hollow glass spheres 20 is disintegrated by the electrolyte solution 14 until a wall of the hollow glass spheres 20 (i.e., their glass shell) collapses, thus releasing the content.

[0036] In the depicted embodiment, the hollow glass spheres 20 are embedded in a coating (not shown) on the inner side of the housing 10 but such that there is contact with the electrolyte solution 14.

[0037] In alternative or optionally additional embodiments—shown with dashed lines in FIG. 2—the hollow glass spheres 20 are embedded in a corresponding coating of the separator 16 and/or the contact lugs 18 (for the sake of clarity, only one side of the separator 16 and one contact lug 18 are shown).

[0038] In order to be able to specify the time at which the content of the hollow glass spheres 20 is released and thus the duration of their dissolution, a wall thickness of the hollow glass spheres 20 is selected to be correspondingly thick (large wall thickness value) or thin. In order to extend the release period for as long as possible, hollow glass spheres 20 with different wall thickness values are used. For clarification, the hollow glass spheres 20 in FIG. 2 are shown with different sizes.

[0039] The subject matter of the invention is not restricted to the embodiments described above. Instead, further embodiments of the invention can be derived by a person skilled in the art from the above description. In particular, the individual features of the invention and their design variants described with reference to the different embodiments can also be combined with one another in other ways.

LIST OF REFERENCE SIGNS

[0040] 1 Motor vehicle

[0041] 2 Electric motor

[0042] 4 Traction battery

[0043] 6 Battery module

[0044] 8 Secondary cell

[0045] 10 Housing

[0046] 12 Electrode

[0047] 14 Electrolyte solution

[0048] 16 Separator

[0049] 18 Contact lug

[0050] 20 Hollow glass sphere