ELECTRODE ASSEMBLY WITH HEAT SPREADING LAYER, BATTERY CELL AND BATTERY EMPLOYING SUCH ELECTRODE ASSEMBLIES

Abstract

Disclosed herein is an electrode assembly, comprising in a stacked manner a first anode layer, an anode current collector layer, a second anode layer, a separator layer, a first cathode layer, a cathode current collector layer, and a second cathode layer. In the electrode assembly, the anode current collector layer and/or the cathode current collector layer comprises at least two conductive layers wherein between neighbouring pairs of conductive layers, a respective heat spreading layer is interposed.

Claims

1. An electrode assembly, comprising in a stacked manner: a first anode layer; an anode current collector layer; a second anode layer; a separator layer; a first cathode layer; a cathode current collector layer and a second cathode layer characterized in that the anode current collector layer and/or the cathode current collector layer comprises at least two conductive layers wherein between neighbouring pairs of conductive layers, a respective heat spreading layer is interposed.

2. The electrode assembly according to claim 1, wherein the at least one heat spreading layer has a thermal conductivity that is larger than 200 W/(mK).

3. The electrode assembly according to claim 1, wherein the at least one heat spreading layer is made from a carbon material, in particular a pyrolytic carbon material.

4. The electrode assembly according to claim 1, wherein the at least one heat spreading layer has a thickness between 0.5 .Math.m and 200 .Math.m.

5. The electrode assembly according to claim 1, wherein the at least one heat spreading layer around its edges is connected to its neighbouring conductive layers in a gas-tight manner.

6. The electrode assembly according to claim 1, wherein the anode layers comprise a carbon material and/or the cathode layers comprise an NMC 811 material.

7. The electrode assembly according to claim 1, wherein the conductive layers of the anode current collector layer comprise a copper material and/or the conductive layers of the cathode current collector layer comprise an aluminium material.

8. The electrode assembly according to claim 1, wherein the separator layer comprises a plastic material.

9. A battery cell, comprising an electrode assembly according to claim 1.

10. The battery cell according to claim 9 in the form of a pouch-type battery cell, wherein the electrode assembly is accommodated within a laminated film.

11. The battery cell according to claim 10, wherein the laminated film also comprises at least one heat spreading layer.

12. The battery cell according to claim 11, wherein at least one heat spreading layer of the electrode assembly is connected to at least one heat spreading layer of the laminated film.

13. The battery, comprising at least one battery cell according to claim 9.

14. The battery according to claim 13, further comprising a thermal management system adapted to control temperature of the at least one battery cell, wherein said thermal management system includes active cooling means and/or passive cooling means.

15. The battery according to claim 13, wherein the battery is adapted to drive an electric aircraft engine, in particular an engine of an electric vertical take-off and landing aircraft, wherein the engine is rotatable between a hover position, in which a thrust direction of the engine is substantially parallel to the vertical axis of the aircraft, and a cruise position, in which a thrust direction of the engine is substantially parallel to the longitudinal axis of the aircraft.

Description

[0018] Further features and advantages of the present invention will become even clearer from the following description of an embodiment thereof, when taken together with the accompanying drawings. Said drawings show in particular:

[0019] FIG. 1A a schematic view of the layer structure of an electrode assembly known from the prior art;

[0020] FIG. 1B a schematic view of the layer structure of an electrode assembly according to the present invention;

[0021] FIG. 2 a schematic cross section of a pouch-type battery cell according to an embodiment of the present invention; and

[0022] FIG. 3 a battery according to an embodiment of the present invention, comprising a plurality of pouch-type battery cells.

[0023] In FIG. 1A, the layer structure of an electrode assembly as known from the prior art is shown in a schematic view and generally denoted with reference numeral 10. Said electrode assembly from top to bottom comprises a first anode layer 12, an anode current collector layer 14, for example made from copper material, a second anode layer 16, wherein the first anode layer 12 and the second anode layer 16 may be made from a carbon material, a separator layer 18, for example made from a plastic material, a first cathode layer 20, a cathode current collector layer 22, for example made from an aluminum material, and a second cathode layer 24, wherein the first and second cathode layers 20 and 24 may be made from NMC 811 material. Said layers 12 to 24 can be stacked by means of manufacturing techniques which have been known in the art.

[0024] On the other hand, FIG. 1B in a similar view shows an electrode assembly according to the present invention, which is denoted with reference numeral 100 and which comprises similar layers, all referred to by the same reference numerals as in FIG. 1A, to which 100 has been added. Thus, the electrode assembly according to the present invention comprises a first anode layer 112, an anode current collector layer 114, a second anode layer 116, a separator layer 118, a first cathode layer 120, a cathode current collector layer 122 and a second cathode layer 124.

[0025] The difference between the electrode assembly 10 shown in FIG. 1A and known from the prior art and the electrode assembly 100 shown in FIG. 1B and according to the present invention is that the cathode current collector layer 122 comprises two conductive layers 122a and 122c, wherein between said conductive layers 122a and 122c, a heat spreading layer 122b is interposed. Said heat spreading layer 122b may for example be made from pyrolytic carbon material and it shall be stated in a similar way, the anode current collector layer 114 of the electrode assembly of FIG. 1B could in alternative embodiments of the present invention also be provided in a multi-layer design with at least one heat spreading layer interposed between neighboring pairs of conductive layers.

[0026] By introducing the respective heat spreading layer 122b into the cathode current collector layer 122 and/or the anode current collector layer 114, an improved distribution of heat is achieved within the active area of the electrode assembly 100 according to the present invention and temperature gradients therein are avoided or at least reduced. This leads to improved performance of the resulting battery cell as well as improved longevity thereof. It shall be stated that the present invention is also applicable to different variations of electrode assemblies, for example comprising at least two pairs of anode layers or cathode layers and additional separator layers.

[0027] FIG. 2 shows a pouch-type battery cell 200 according to an embodiment of the present invention in a cross section view. The battery cell 200 comprises the electrode assembly 100 mentioned above in relation with FIG. 1B. In particular, the electrode assembly 100 comprises the layer structure discussed above and is preferably a lithium-ion electrode assembly or a lithium-polymer electrode assembly, the electro-chemical working principle of which is known as such in the prior art. The electrode assembly 100 is accommodated within a pouch 202 made from one or more laminated films and may in turn also comprise heat spreading layers in a similar manner as discussed above for the electrode assembly 100. Tab connectors 204 are electrically connected to the electrodes of the electrode assembly 100, in particular to the anode current collector layer 114 and to the cathode current collector 122. For that purpose, the tab connectors are provided such as to penetrate the pouch 202 to the exterior of the pouch and to allow electrical connection of the battery cell 200.

[0028] Lastly, FIG. 3 shows a battery 300 according to an embodiment of the present invention. Battery 300 comprises a plurality of pouch-type cells 200, each having a pouch 202 and an electrode assembly 100 as described above. In particular, each of the cells 200 may be configured as described above with reference to FIG. 2.

[0029] The battery cells 200 are stacked in parallel to one another such as to form a cell stack. To maintain mechanical integrity of the cell stacks, battery 300 comprises a frame or housing 302 holding the cells 200 in position and allowing handling of the battery 300 as a single unit. Furthermore, battery 300 comprises electric connection means 304 for connecting all cells 200 in parallel or in series, depending on the required characteristics of the battery, thus suitably connecting the contact tabs 204 of the cell 200 together and to battery terminals 306.

[0030] In addition, battery 300 may comprise a thermal management system 308, which includes a heat conductor 310, which is in direct contact with the pouches of all cells 200, as well as a cooling device 312 for cooling the heat conductor. The heat conductor may be a metal strip or a metal bar. The cooling device 312 may be an active cooling device such as a fan, a heat exchanger, etc., or a passive cooling device such as a plurality of cooling ribs. Alternatively, heat conductor 310 may be thermally connected to an external heat sink to transport heat away from the battery 300.

[0031] In addition, the thermal management system 308 may comprise means for monitoring and controlling the temperature, for example a temperature sensor or electronics to control an active cooling device depending on the measured temperature.