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DE-102024133218-A1 - Bipolar accumulator, method for manufacturing an accumulator and motor vehicle with an accumulator

DE102024133218A1DE 102024133218 A1DE102024133218 A1DE 102024133218A1DE-102024133218-A1

Abstract

The invention relates to a bipolar accumulator for storing electrical energy, wherein a plurality of electrical cells are arranged in multiple layers. Each cell has an anode and a cathode, each of which is applied to a support layer. Between each pair of adjacent cells, a support layer is arranged on which the anode of one of the two adjacent cells and the cathode of the other of the two adjacent cells are applied. The anode and the cathode are electrically connected to each other by the support layer. The support layer is made of electrically conductive plastic. The support layer comprises a metallic structure extending parallel to the support layer over a planar area.

Inventors

  • Michael Deutmeyer
  • Klaus Brandt

Assignees

  • Monbat New Power GmbH

Dates

Publication Date
20260513
Application Date
20241113

Claims (15)

  1. Bipolar accumulator (10), in particular a bipolar lithium-ion accumulator (10), for storing electrical energy, wherein a plurality of electrical cells (12) are arranged in multiple layers one above the other, wherein each cell (12) has an anode and a cathode, each of which is applied to a support layer (14), wherein a support layer (14) is arranged between each pair of adjacent cells (12), on which the anode of one of the two adjacent cells (12) and the cathode of the other of the two adjacent cells (12) is applied, and the anode and the cathode are electrically connected to each other by the support layer (14), wherein the support layer (14) is made mostly of electrically conductive plastic, characterized in that the support layer (14) comprises a metallic structure extending in a planar fashion parallel to the support layer (14).
  2. Bipolar accumulator (10) for storing electrical energy according to Claim 1 , characterized in that the carrier layer (14) is based on a plastic film.
  3. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims, characterized in that the metallic structure is a metallic coating (32).
  4. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims, characterized in that the metallic coating has a thickness of at least 0.02 µm, in particular at least 0.05 µm, and/or at most 0.2 µm, in particular at most 0.1 µm.
  5. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims, wherein the support layer (14) has a thickness of at least 4 µm, in particular at least 6 µm, and/or at most 20 µm, in particular at most 10 µm.
  6. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims, wherein a surface of the support layer (14) on which the anode is applied and/or a surface of the support layer (14) on which the cathode is applied each has an area of at least 1,000 cm² , in particular at least 2,000 cm² , and/or at most 30,000 cm² , in particular at most 10,000 cm² .
  7. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims (14), characterized in that the support layers (14) of the cells extend in planes parallel to each other.
  8. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims, characterized in that the electrically conductive plastic is a plastic comprising an electrically conductive filler, in particular carbon.
  9. Bipolar accumulator (10) for storing electrical energy according to one of the preceding claims, characterized in that the accumulator (10) has a sealing (26) of the cells (12), in particular wherein edge areas (30) of the carrier layers (14) are used for sealing (26) of the cells (12).
  10. Bipolar accumulator (10) for storing electrical energy according to Claim 4 , characterized in that the support layers (14) areas (32) that protrude outwards from the sealing (26) of the cells (12) and can be used for contacting the individual cells by a battery management system.
  11. Bipolar accumulator (10) for storing electrical energy according to Claim 4 or 5 , characterized in that the seals (26) of the individual cells (12) have closed passages (28).
  12. Method for manufacturing a bipolar accumulator (10) for storing electrical energy according to one of the Claims 3 until 11 , characterized in that the metallic coating (32) is vapor-deposited onto a base layer (34) of the carrier layer (14).
  13. motor vehicle with a bipolar accumulator according to one of the Claims 1 until 11 or one involving a procedure according to one of the Claims 12 manufactured bipolar accumulator (10).
  14. motor vehicle Claim 13 , characterized in that the support layers (14) are aligned, at least substantially, parallel to a plane spanned by the longitudinal and transverse directions of the motor vehicle.
  15. motor vehicle Claim 13 or 14 , characterized in that the accumulator (10) is arranged in the area of the underbody of the motor vehicle.

Description

The invention relates to a bipolar accumulator according to the preamble of claim 1, as well as a method for manufacturing such a bipolar accumulator and a motor vehicle with such an accumulator or an accumulator manufactured according to such a method. Bipolar batteries are fundamentally known. They are batteries that are based on the principle of a voltaic pile. Bipolar batteries of this type contain multiple electrical cells arranged in layers. Each cell has an anode and a cathode, each mounted on a carrier layer. The distinguishing feature of a bipolar battery is that an electrically conductive carrier layer is positioned between each pair of adjacent cells. On this carrier layer, the anode of one of the two adjacent cells and the cathode of the other are located. The two adjacent cells are electrically connected to each other via this carrier layer. In simpler terms, a bipolar battery combines multiple batteries connected in series. Furthermore, accumulators of the type in question contain an electrolyte. The electrolyte enables the transport of ions between the anode and cathode. Accordingly, the electrolyte is located between the anode and cathode. The electrolyte can be in the form of a liquid, a solid, and/or a gel. As a rule, the electrolytes of individual cells must be kept separate from one another. This applies particularly to liquid electrolytes. Such bipolar batteries inherently possess high potential. In principle, a single compact bipolar battery can replace an array of multiple conventional batteries connected in series. This would result in weight and cost savings. Nevertheless, bipolar batteries have not become established in technology. This is due, for example, to the fact that many battery types, such as lithium-ion batteries, cannot be easily implemented as bipolar batteries. However, lithium-ion batteries are currently the battery type of choice in the vast majority of applications due to their excellent properties. It would therefore be desirable to create a battery that makes the advantages of a bipolar battery available for such battery types, especially lithium-ion batteries. In practice, however, this presents a number of problems. For example, conventional batteries use metal layers as substrates for the electrodes. Their primary function is to conduct current to the electrode during charging and/or discharging. This is achieved primarily due to the excellent conductivity of the metal substrates. They offer relatively little resistance to the current when it flows in a direction parallel to the main orientation of the substrate (and thus also the electrode layer), even if the cross-section of the substrate is comparatively small in such a current flow direction. In other words, the metallic substrates can thus ensure a good "surface distribution" of the current to and from the respective electrode. However, bipolar batteries present the problem that the substrate layer must be suitable for both the anode and the cathode. For example, conventional lithium-ion batteries typically use aluminum foil for the cathode and copper foil for the anode. However, it has been shown that aluminum foil is unsuitable as an anode substrate, while copper foil is unsuitable as a cathode substrate. This unsuitability stems from the fact that the metallic foils must not participate in the reactions within the cells. Aluminum foils, however, form an alloy with lithium even at room temperature when used as the anode material. Copper foils, on the other hand, are oxidized when used as a cathode substrate due to their positive electrical potential (an aluminum foil, when used as a cathode substrate, is protected from further corrosion by a stable oxide layer – a so-called passivation layer). Therefore, the search for a suitable substrate layer presents a crucial problem when it comes to developing bipolar lithium-ion batteries that meet today's battery requirements, especially regarding their durability. Another problem in the production of bipolar batteries is the different coating requirements on the cathode and anode sides. The anode layer, as well as the cathode layer, respectively... Their precursors – mostly doughy-pasty masses – have different properties, making a carrier layer with both layers difficult to handle from a process engineering perspective. It has been demonstrated in the past that electrically conductive plastics can be used to produce carrier layers that are suitable, in terms of their mechanical and, in particular, chemical properties, for use as a carrier layer in bipolar batteries. It has been shown that the conductivity of such carrier layers made of conductive plastics is quite sufficient to ensure adequate conductivity of the carrier layer in a bipolar battery. This is primarily because, in bipolar batteries, the currents flow in a direction perpendicular to the main orientations of the carrier layers. This allows the use of a material with a significantly lower conductivity