Carbon buffer layer for a battery cell

Abstract

A method for manufacturing a battery cell 16 comprises applying a carbon buffer layer 10 to a surface 13 of a current collector 24 as a coating process, wherein the current collector is an anode 22; and comprising interposing an electrolyte 12 between a cathode 14 and the anode, wherein the electrolyte is a solid electrolyte separator. A battery cell for a battery module manufactured according to the method is also claimed. The carbon buffer layer may be deposited on the current collector by Atomic Layer Deposition (ALD) or Physical Vapour Deposition (PVD). The carbon buffer layer may comprise carbon and a metal, preferably in the form of a Li-eutectic alloy, and may be amorphous. The carbon buffer layer is stated to enhance efficiency, reliability and lifespan of the battery cell by ensuring that lithium ions are deposited on the current collector uniformly by facilitating even distribution of the lithium ions.

Description

FIELD OF THE INVENTION

[0001] The present invention relates to the field of automobiles. More specifically, the present invention relates to a method for manufacturing a battery cell for electric vehicles according to claim 1. Furthermore, the present invention relates to a corresponding battery cell for electric vehicles. BACKGROUND INFORMATION

[0002] Document US 2022 27 13 34 AA discloses a method of stabilizing a garnet-type Solid State Electrolyte (SSE) which includes obtaining pellets of SSE, removing surface impurities of the SSE and depositing a passivation layer onto the SSE after the surface impurities are removed as the passivation layer including two of boron, carbon, and nitrogen. SUMMARY OF THE INVENTION

[0003] The objective of the present invention is to provide a carbon buffer layer between an electrolyte and a current collector of a battery cell.

[0004] This objective is achieved by a method for manufacturing a battery cell having the features of claim 1 and by a corresponding battery cell. Advantageous embodiments of the present invention may be found in the dependent claims.

[0005] The present invention relates to a method for manufacturing a battery cell comprising applying a carbon buffer layer to a surface of a current collector as a coating process, wherein the current collector is an anode. In some embodiments, the carbon buffer layer may be applied to a solid electrolyte separator and / or the current collector.

[0006] The method also comprises interposing an electrolyte between a cathode and the anode, wherein the electrolyte is a solid electrolyte separator. The cathode electrode may be LFP, NMC, LNMO, NCA, for example.

[0007] An aspect of the present invention relates to a carbon buffer layer between a solid electrolyte and a current collector to enable deposition of a uniform plating of the lithium-ions Li+, wherein the lithium ions are provided from a cathode structure of the battery whereby an atomic layer deposition (ALD) can be performed as the coating process to apply the carbon buffer layer on a surface of the current collector.

[0008] The method of applying a carbon buffer layer on the current collector may also be implemented via physical vapor deposition (PVD).

[0009] This present invention presents a battery cell layers designed to improve the performance of lithium-ion batteries by ensuring uniform lithium-ion deposition by lowering the nucleation potential.

[0010] Overall, the battery cell with a carbon buffer layer aims to enhance the efficiency, reliability, and lifespan of lithium ion batteries by ensuring that lithium ions are deposited uniformly, which may lead to improved battery performance and longevity.

[0011] With the present invention, the lithium ions may reach the current collector via the carbon buffer layer, where they are uniformly deposited. The carbon buffer layer may facilitate the even distribution of lithium ions on the surface of the current collector and prevents uneven deposition. This, in turn, enhances the performance and lifespan of the battery while also mitigating potential issues, such as dendrite formation, which could otherwise lead to short circuits.

[0012] In summary, this present invention of a battery cell a carbon buffer layer deposited via ALD or PVD on the current collector may enable uniform lithium ion such as LiO or Li or Li- metal plating on the current collector.

[0013] Further advantages, features, and details of the present invention derive from the following description of preferred embodiments as well as from the drawings. The features and feature combinations previously mentioned in the description as well as the features and feature combinations mentioned in the following description of the figures and / or shown in the figures alone can be employed not only in the respectively indicated combination but also in any other combination or taken alone without leaving the scope of the invention. BRIEF DESCRIPTION OF THE DRAWING

[0014] The novel features and characteristic of the present disclosure are set forth in the appended claims. The accompanying drawings, which are incorporated in and constitute a part of this disclosure, illustrate exemplary embodiments and together with the description, serve to explain the disclosed principles. In the figures, the left-most digit(s) of a reference number identifies the figure in which the reference number first appears. The same numbers are used throughout the figures to reference like features and components. Some embodiments of system and / or methods in accordance with embodiments of the present subject matter are now described below, by way of example only, and with reference to the accompanying figures.

[0015] The drawing shows in:

[0016] Fig. 1 a cross-section of a battery cell with a carbon buffer layer to illustrate the flow of lithium-ions from the cathode to the anode.

[0017] In the figure the same elements or elements having the same function are indicated by the same reference signs. DETAILED DESCRIPTION

[0018] In the present document, the word "exemplary" is used herein to mean "serving as an example, instance, or illustration". Any embodiment or implementation of the present subject matter described herein as "exemplary" is not necessarily to be construed as preferred or advantageous over other embodiments.

[0019] While the present disclosure is susceptible to various modifications and alternative forms, specific embodiments thereof have been shown by way of example in the drawing and will be described in detail below. It should be understood, however, that it is not intended to limit the disclosure to the particular forms disclosed, but on the contrary, the disclosure is to cover all modifications, equivalents, and alternatives falling within the scope of the disclosure.

[0020] The terms “comprises”, “comprising”, or any other variations thereof, are intended to cover a non-exclusive inclusion so that a setup, device or method that comprises a list of components or steps does not include only those components or steps but may include other components or steps not expressly listed or inherent to such setup or device or method. In other words, one or more elements in a system or apparatus preceded by “comprises” or “comprise” does not or do not, without more constraints, preclude the existence of other elements or additional elements in the system or method.

[0021] In the following detailed description of the embodiment of the present disclosure, reference is made to the accompanying drawing that forms part hereof, and in which is shown by way of illustration a specific embodiment in which the disclosure may be practiced. This embodiment is described in sufficient detail to enable those skilled in the art to practice the disclosure, and it is to be understood that other embodiments may be utilized and that changes may be made without departing from the scope of the present disclosure. The following description is, therefore, not to be taken in a limiting sense.

[0022] Fig. 1 a cross-section of a battery cell 16 with a carbon buffer layer 10 as the second interface 20 to illustrate the flow of lithium-ions Li+ from the cathode 14 to the anode 22.

[0023] In the illustration of Fig. 1 the battery cathode structure 14a serves as the source of lithium ions Li+, needed for the charging process. The carbon buffer layer 10 may be deposited as a layer between electrolyte 12 and a current collector 24. The battery cell 16 includes the carbon buffer layer 10 that may be deposited via atomic layer deposition (ALD) as the coating technique to the surface 13 of the current collector 24. In another embodiment, the carbon buffer layer 10 may be deposited via physical vapor deposition (PVD), a cold plasma deposition, a different vapor process, or another comparable process.

[0024] With the carbon buffer layer 10, the transport of lithium-ions Li+ may be improved. For example, the transport of the Li+ may start within the cathode structure 14a of the cathode 14 such as a lattice structure and may proceed towards the surface 13 of the anode 22 / current collector 24. The lithium-ions Li+ may traverse a first interface 18 located between the cathode 14 and an electrolyte 12, in particular a solid electrolyte 12, facilitating the transition from the cathode 14 to the electrolyte 12. Within the solid electrolyte 12, the electrolyte 12 may perform the functions of a separator and ion conductor. The solid electrolyte 12 may comprises oxides, sulfides, polymers, or composite materials with a high ionic conductivity such as more than 10-3 S / cm at ambient temperatures. Furthermore, it is also possible to use halides so that there is no limitation to using only batteries with specific solid electrolytes.

[0025] The structure 12a of the solid electrolyte may be a crystalline or amorphous structure 12a.

[0026] The lithium ions Li+ may continue their transition through the electrolyte 12 and into the second interface 20. The second interface 20 may be the carbon buffer layer 10 that separates the solid electrolyte 12 from the anode 22 within the battery cell 16, representing another transition point in the pathway. The carbon buffer layer 10 may be amorphous with a low surface area. Additionally, the carbon buffer layer 10 may be blended with metals that form Li-eutectic alloys at a relatively low temperature.

[0027] After passing through the carbon buffer layer 10 which may minimize the slow Li intercalation, the lithium ions Li+ reach and are uniformly deposited on the anode 22, current collector 24. This carbon buffer layer 10 may ensure even distribution of lithium ions Li+ on the surface 13 of the anode 22, current collector 24, minimizing the risk of undesirable irregular deposits and a haze in the performance of the battery cell 16. The battery cell 16 may be combined with more battery cells 16 to form a battery module (not shown), which may be one component of a battery pack (not shown) for an electric vehicle (not shown).

[0028] In summary, Fig. 1 visually presents the improvement to the flow of Li+ in the battery cell 16, showing key components for uniform Li+ plating in the battery cell 16 during the charging process. The steps involved manufacturing the battery cell 16 with the carbon buffer layer 10 for a battery system include the following steps.

[0029] The first step is applying a carbon buffer layer 10 to a surface 13 of a current collector 24, wherein the current collector 24 is an anode 22, The second step is interposing an electrolyte 12 between a cathode 14 and the anode 22, wherein the electrolyte 12 is a solid electrolyte separator.

[0030] The specialized coating technique known as the atomic layer deposition ALD may be employed. This technique allows for precise deposition of material layers, one atomic layer at a time, and is used to apply a carbon buffer layer to the surface of the solid electrolyte. The choice of ALD as the coating process enables precise control of the layer thickness and distribution of material. This precise control over layer thickness and material distribution may be essential for optimizing battery performance. Signs carbon buffer layer electrolyte structure surface cathode cathode structure battery cell first interface second interface anode current collector atomic layer deposition lithium ions

Claims

1. A method for manufacturing a battery cell (16) comprising;- applying a carbon buffer layer (10) to a surface (13) of a current collector (24) as a coating process, wherein the current collector (24) is an anode (22); and- interposing an electrolyte (12) between a cathode (14) and the anode (22), wherein the electrolyte (12) is a solid electrolyte separator.

2. The method according to claim 1, wherein an Atomic Layer Deposition (ALD) is performed as the coating process to apply the carbon buffer layer (10).

3. The method according to claim 1, wherein a Physical Vapor Deposition (PVD) is performed as the coating process to apply the carbon buffer layer (10).

4. The method according to claims 1 to 3, wherein the carbon buffer layer (10) comprises carbon and a metal.

5. The method according to any one of the preceding claims, wherein the carbon buffer layer (10) is amorphous.

6. The method according to claim 4,wherein the carbon buffer layer (10) is a Li-eutetic alloy.

7. A battery cell (16) for a battery module manufactured according to a method according to any one of claims 1 to 6.

Images