Anode-free solid-state battery and use thereof

Abstract

The invention relates to an anode-free solid-state battery (200) comprising a cathode (110), a solid-state electrolyte separator (120), and an arrester (130), wherein an additional solid-state electrolyte layer (125) is arranged between the solid-state electrolyte separator (120) and the arrester (130). The invention is characterized in that as a result of the improved deformability, contact losses between the solid-state electrolyte separator (120) and the arrester (130) via the additional solid-state electrolyte layer (125) are prevented, and the contact is maintained also during the charging cycles (charging / discharging).

Description

[0001] Anode-free solid-state battery and its use

[0002] The invention relates to an anode-free solid-state battery and its use.

[0003] In battery technology, lithium-ion-based battery systems have become increasingly popular in recent years. These systems are characterized by their high energy density and expected long service life, enabling more efficient battery configurations. The high chemical reactivity and low mass of lithium ions, as well as their high mobility, play a key role in this.

[0004] A battery consists of three layers: anode, separator, and cathode. The anode and cathode store the active energy via lithium ions, and the separator provides insulation between the electrodes. In a solid-state battery, the charge carriers, in the form of lithium ions, are transported through a solid-state electrolyte during charging and discharging.

[0005] Anode-free solid-state batteries do not have an anode made of the commonly used graphite material. Common anode materials for lithium-ion batteries, such as graphite, are based on a so-called host lattice into which lithium is intercalated and released. Anode-free solid-state batteries use a metal contact, i.e. a metal anode, such as a lithium metal anode, at which the lithium ions discharge, causing metallic lithium to grow. The anode is therefore formed by the deposition of metallic lithium during battery charging, and during discharge the lithium anode completely dissolves again. The term "anode-free" is therefore not to be taken literally, but is a common technical term in this field. The omission of the classic anode results in a number of advantages: For example, a host lattice is no longer required, which saves volume and weight.Costs in series production are reduced. Furthermore, metal anodes can significantly increase the volume- and mass-related energy densities.

[0006] For example, US 2021 / 0036377 A1 discloses a cylindrical anode-free anti-dendrite all-solid-state battery comprising: a cathode layer; a cathode current collector layer connected to the cathode layer; an anode current collector layer; an anti-dendrite layer disposed between the anode current collector layer and the cathode layer; a lithium gel separator layer disposed between the cathode layer and the anti-dendrite layer; and a container in which the cathode layer, the cathode current collector layer, the anode current collector layer, the anti-dendrite layer, and the lithium gel separator layer are inserted.

[0007] DE 10 2022 115 008 A1 relates to an electrochemical cell that cyclically moves lithium ions, comprising a positive electrode, a negative electrode current collector spaced from the positive electrode, and an ionically conductive electrolyte disposed between the positive electrode and the negative electrode current collector. The negative electrode current collector is made from a single piece and has a three-dimensional porous structure forming a continuous network of open pores. When the electrochemical cell is charged, lithium metal is deposited in the open pores of the negative electrode current collector.

[0008] However, anode-free solid-state batteries have the disadvantage that a contact problem can occur between the metal contact in the form of an anode-free arrester and the solid-state electrolyte separator, especially in secondary, anode-free solid-state batteries.

[0009] The production of an anode-free solid-state battery, particularly a secondary anode-free solid-state battery, is achieved by pressing together conventional components, i.e., a cathode comprising cathode active material, a solid-state electrolyte separator, and an anode-free arrester or metal arrester. For example, in "High-energy long-cycling all-solid-state lithium metal batteries enabled by silver-carbon composite anodes" from Nature Energy, Volume 5, pp. 299-308 (2020) (https: / / doi.org / 10.1038 / s41560-020-Q575-z), Yong-Gun Lee et al. disclose isostatic pressing of the components together to establish contact between the individual components, which are then installed between two metal plates. Continuous pressure is exerted on the component stack by the components pressed together between the metal plates. The manufactured solid-state battery can then be subjected to a conventional charging cycle.

[0010] Since the anode in an anode-free solid-state battery is formed by the deposition of metallic lithium during battery charging, and the lithium anode completely dissolves during discharging, volume changes occur. This leads to a loss of contact between the arrester and the solid-state electrolyte during the charging cycle, as the volume of the component stack changes during charging and discharging.

[0011] The present invention is therefore based on the object of avoiding the disadvantages of the prior art and of avoiding contact problems between an arrester and a solid electrolyte separator in an anode-free solid-state battery, in particular in a secondary, anode-free solid-state battery.

[0012] According to the invention, the above object is achieved by an anode-free solid-state battery, in particular a secondary, anode-free solid-state battery, comprising a cathode, a solid-state electrolyte separator and a conductor, wherein an additional solid-state electrolyte layer is arranged between the solid-state electrolyte separator and the conductor.

[0013] The present invention therefore provides a solid-state battery that solves the contact problem in a relatively simple manner. In the solid-state battery according to the invention, an additional solid electrolyte layer is located between the solid electrolyte separator and the collector. This additional solid electrolyte layer enables better deformability and thus significantly increases the contact between the additional solid electrolyte layer and the collector, and thus also between the solid electrolyte separator and the collector via the additional solid electrolyte layer. Furthermore, it has been found that this additional solid electrolyte layer also ensures that contact between the solid electrolyte separator and the collector is maintained during charging cycles (charging / discharging).The frequently observed loss of contact, particularly caused by volume changes of the component stack during charging and discharging of a solid-state battery, is therefore avoided according to the invention.

[0014] According to one embodiment, it is advantageous if the additional solid electrolyte layer is selected to be thinner than the solid electrolyte separator. This further improves the formability, so that mutual contact of the adjacent components with the additional solid electrolyte layer can be ensured in every case.

[0015] According to the invention, the additional solid electrolyte layer can have the same or a different composition as the solid electrolyte separator. Preferably, the additional solid electrolyte layer has a different composition than the solid electrolyte separator.

[0016] According to the invention, the solid electrolyte separator contains a binder component. It is preferred according to the invention if the additional solid electrolyte layer has a higher binder component than the solid electrolyte separator. Preferably, the binder component in the additional solid electrolyte layer is at least 5 wt.% higher than in the solid electrolyte separator. This further increases the elasticity of the additional solid electrolyte layer, thereby supporting its deformability and facilitating the return of the additional solid electrolyte layer to its original position.

[0017] The anode-free solid-state battery of the present invention comprises a cathode material layer, an anode-free conductor, and a layer of a solid electrolyte separator arranged therebetween.

[0018] The cathode material layer of the anode-free solid-state battery comprises, for example, at least one cathode-active material and may contain a solid electrolyte material, a conductive material, such as conductive carbon black, and a binder. For example, a cathode-active material may be LiCoO2, LiNO2, or Li y Ni(ipw)MpN w 02, where 0.8 < y < 1,2, 0 < p < 0.33, 0 < w < 0.33, where M and N are selected from Mn, Co, Al. The thickness of the cathode material layer is preferably in the range of 0.1 pm to 1000 pm. The anode-free solid-state battery also has a solid-state electrolyte separator that spatially and electrically separates the conductor and the cathode.

[0019] The arrester is a metal arrester, made of copper or steel, for example. The arrester is coated with an anode-free primer, which may contain conductive material, such as conductive carbon black, as well as metal particles, especially nanoscale metal particles.

[0020] Preferably, the anode-free solid-state battery of the present invention is a high power output battery.

[0021] The anode-free solid-state battery of the present invention can be a secondary battery that can be repeatedly charged and discharged. Primary batteries can only be discharged once and cannot be recharged afterward. Secondary batteries, also called accumulators, are rechargeable. For example, the anode-free solid-state battery of the present invention can be installed in an electric vehicle.

[0022] The invention also relates to the use of the anode-free solid-state battery of the present invention in an electrically powered vehicle (BEV, battery electric vehicle).

[0023] The invention also relates to an electrically powered vehicle (BEV) with one or more secondary, anode-free solid-state batteries.

[0024] The present invention is explained in more detail with reference to the following embodiment, wherein the attached figures are schematic and not drawn to scale, so that no assumption can be made about exact geometric values ​​with respect to the original size. The figures of the present disclosure are part of and constitute a part of the description, and the embodiment shown illustrates the present invention without limiting the invention thereto.

[0025] Showing:

[0026] Fig. 1: a schematically simplified representation of a structure of an anode-free solid-state battery from the prior art and Fig. 2: a schematically simplified representation of the structure of an anode-free solid-state battery according to an embodiment of the present invention.

[0027] Fig. 1 schematically illustrates the structure of a prior art anode-free solid-state battery 100. The cathode 110 comprises a cathode-active material, a solid electrolyte material, a conductive material such as conductive carbon black, and a binder. The anode-free solid-state battery 100 also has a solid electrolyte separator 120, which spatially and electrically separates the anode-free collector 130 and the cathode 110.

[0028] Fig. 2 schematically illustrates the structure of an anode-free solid-state battery 200 according to an embodiment of the present invention. Additionally, in the anode-free solid-state battery 200 of the present invention, a solid electrolyte layer 125 is disposed between the solid electrolyte separator 120 and the collector 130. The additional solid electrolyte layer 125 improves the easier deformability of the adjacent components and thereby prevents a loss of contact between the solid electrolyte separator 120 and the collector 130. In particular, the improved contact is maintained in a secondary, anode-free solid-state battery despite the volume changes typically occurring during charging / discharging cycles.

[0029] In Fig. 2, the additional solid electrolyte layer 125 is thinner than the solid electrolyte separator 120. This further improves the deformability of the additional solid electrolyte layer 125, so that mutual contact with the adjacent components, the solid electrolyte separator 120 and the arrester 130, can be ensured in any case.

[0030] The additional solid electrolyte layer 125 preferably has a different composition than the solid electrolyte separator 120. In particular, the additional solid electrolyte layer 125 has a higher binder content than the solid electrolyte separator 120. Particularly preferably, the binder content in the additional solid electrolyte layer 125 is at least 5 wt.% higher than in the solid electrolyte separator 120. If the binder content in the solid electrolyte separator 120 is, for example, 5 wt.%, the binder content in the additional solid electrolyte layer 125 is > 10 wt.%. The higher binder content in the additional solid electrolyte layer 125 results in greater elasticity of the layer 125, which supports deformability and facilitates the return of the additional solid electrolyte layer 125 to its original position upon deformation.

[0031] According to the invention, for the first time, by providing an additional solid electrolyte layer between the solid electrolyte separator and the arrester, the contact is improved and maintained even during the charging cycles, so that the contact losses of the components that usually occur in an anode-free solid-state battery, in particular a secondary, anode-free solid-state battery, are avoided.

[0032] List of reference symbols

[0033] 100 state-of-the-art anode-free solid-state batteries

[0034] 110 Cathode

[0035] 120 solid-state electrolyte separator

[0036] 125 additional solid electrolyte layer

[0037] 130 arresters

[0038] 200 anode-free solid-state battery according to an inventive

[0039] Embodiment

Claims

Patent claims 1. Anode-free solid-state battery (200), comprising a cathode (110), a solid-state electrolyte separator (120) and a discharger (130), wherein an additional solid-state electrolyte layer (125) is arranged between the solid-state electrolyte separator (120) and the discharger (130).

2. Anode-free solid-state battery (200) according to claim 1, characterized in that the additional solid electrolyte layer (125) has the same composition as the solid electrolyte separator (120).

3. Anode-free solid-state battery (200) according to claim 1, characterized in that the additional solid electrolyte layer (125) has a different composition than the solid electrolyte separator (120).

4. Anode-free solid-state battery (200) according to one of claims 1 to 3, characterized in that the additional solid electrolyte layer (125) is selected to be thinner than the solid electrolyte separator (120).

5. Anode-free solid-state battery (200) according to one of claims 1 to 4, characterized in that the additional solid-state electrolyte layer (125) has a higher binder content than the solid-state electrolyte separator (120).

6. Anode-free solid-state battery (200) according to one of claims 1 to 5, characterized in that the binder content in the additional solid-state electrolyte layer (125) is at least 5 wt.% more than in the solid-state electrolyte separator (120).

7. Anode-free solid-state battery (200) according to one of claims 1 to 6, characterized in that the anode-free solid-state battery (200) is a secondary battery.

8. Use of the anode-free solid-state battery (200) according to one of claims 1 to 7 in an electrically powered vehicle (BEV).

9. An electrically powered vehicle having one or more anode-free solid-state batteries (200), in particular one or more secondary, anode-free solid-state batteries (200), according to one of claims 1 to 7.

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