Battery cell, battery, vehicle and process

Abstract

A battery cell (20) comprises - an anode (31) which contains lithium metal, - a cathode (32), - an asymmetric composite electrolyte (40) with a first layer (41) and with a second layer (42), wherein the first layer (41) is in contact with the anode (31), wherein the second layer (42) is in contact with the cathode (32), wherein the first layer (41) comprises a lithium phosphorus sulfur chloride and a poly(ethylene oxide) as components, and wherein the second layer (42) comprises a lithium aluminum titanium phosphate and a poly(ethylene oxide) as components.

Description

[0001] The invention relates to a battery cell, a battery, a vehicle and a method for manufacturing the battery cell.

[0002] EP 3 567 667 A1 shows a lithium electrode with a current collector.

[0003] CN 111 276 738 A shows an asymmetric solid electrolyte.

[0004] CN 113 346 051 A describes a process for producing a surface protection layer made of metallic lithium.

[0005] CN 1 17 423 892 A shows a two-layer composite solid electrode with a composite polymer layer filled with an active filler.

[0006] CN 1 11 009 683 A shows an asymmetric semi-solid electrolyte in which an electrolyte membrane is formed on the side towards the positive electrode, with lithium salt, a polymer matrix and an inorganic ceramic powder.

[0007] CN 1 12 701 347 A shows an electrochemical device with an electrolyte layer, a positive electrode layer and a negative electrode layer, wherein the electrolyte layer has an electrolyte layer on the side of the positive electrode, a middle electrolyte layer and an electrolyte layer on the side of the negative electrode.

[0008] Poly(ethylene oxide) is a solid electrolyte with positive properties such as high chemical stability with respect to the metal lithium. However, in technical applications, it can present problems with its mechanical strength, low ionic conductivity, and the risk of short circuits due to the growth of lithium dendrites.

[0009] It is therefore an object of the invention to provide a new battery cell, a new battery, a new vehicle and a new method for manufacturing the battery cell.

[0010] This problem is solved by the subject matter of claim 1 and the dependent claims.

[0011] A battery cell comprises - an anode containing lithium metal, - a cathode, - an asymmetric composite electrolyte with a first layer and a second layer, where the first layer is in contact with the anode, where the second layer is in contact with the cathode, wherein the first layer comprises a lithium phosphorus sulfur chloride and a poly(ethylene oxide) as components, and the second layer comprises a lithium-aluminum-titanium phosphate and a poly(ethylene oxide) as components.

[0012] Such a battery cell offers good safety due to its solid-state design. Furthermore, the formation of lithium dendrites is reduced. This enables the development of dendrite-suppressing solid-state lithium-metal batteries.

[0013] According to a preferred embodiment, the anode is designed as a lithium metal anode.

[0014] According to a preferred embodiment, the lithium phosphorus sulfur chloride is provided at least partially as Li6PS5Cl.

[0015] According to a preferred embodiment, the lithium-aluminum-titanium phosphate is at least partially composed of Li 1.3 Al 0.3 Ti 1.7 (PO4)3 provided.

[0016] According to a preferred embodiment, the lithium phosphorus sulfur chloride is present in the form of nanoparticles.

[0017] According to a preferred embodiment, the lithium-aluminium-titanium phosphate is present in the form of nanoparticles.

[0018] According to a preferred embodiment, the lithium-phosphorus-sulfur chloride in the first layer has a mass fraction between 0.02 and 0.07.

[0019] According to a preferred embodiment, the lithium-aluminium-titanium phosphate in the second layer has a mass fraction between 0.10 and 0.25.

[0020] According to a preferred embodiment, the cathode comprises at least one cathode material from a group of cathode materials consisting of: - Lithium iron phosphate (LFP), - Lithium nickel manganese cobalt oxide (NMC), and - Lithium nickel cobalt aluminum oxide (NCA).

[0021] According to a preferred embodiment, the specific capacity of the battery cell is at least as large as at least one first specific capacity from a capacity group consisting of: - 156.3 mAh / g, and - 225 mAh / g.

[0022] According to a preferred embodiment, the ionic conductivity of the asymmetric composite electrolyte is at least as large as at least one first ionic conductivity from an ionic conductivity group consisting of: - 3.00 · 10 -4 S / cm, and - 3.37 · 10 -4 S / cm.

[0023] According to a preferred embodiment, the asymmetric composite electrolyte is produced by a solution casting process.

[0024] A battery has at least one such battery cell.

[0025] A vehicle has at least one such battery.

[0026] In one process for manufacturing such a battery cell, the asymmetric composite electrolyte is produced by a solution casting process.

[0027] Further details and advantageous embodiments of the invention will become apparent from the exemplary embodiments described below and illustrated in the drawing, which are in no way to be understood as limiting the invention, as well as from the dependent claims. It is understood that the features mentioned above and those to be explained below can be used not only in the combinations specified, but also in other combinations or individually, without departing from the scope of the present invention. The drawing shows: Fig. 1 in a schematic representation a vehicle with a battery which has a battery cell.

[0028] In the following, identical or similarly functioning parts are designated with the same reference symbols and are usually described only once. The descriptions build upon each other to avoid unnecessary repetition.

[0029] Fig.Figure 1 shows a schematically indicated vehicle 10. Preferably, the vehicle 10 is a battery-powered vehicle, including a hybrid vehicle.

[0030] Vehicle 10 has a schematically indicated battery 12.

[0031] Battery 12 has at least one battery cell 20.

[0032] The battery cell 20 comprises - an anode 31 which contains lithium metal, - a cathode 32, - an asymmetric composite electrolyte 40 with a layer 41 and with a layer 42.

[0033] Layer 41 is in contact with anode 31.

[0034] Layer 42 is in contact with cathode 32.

[0035] Layer 41 contains lithium phosphorus sulfur chloride and poly(ethylene oxide) as components.

[0036] Layer 42 contains a lithium-aluminium-titanium phosphate and a poly(ethylene oxide) as components.

[0037] Poly(ethylene oxide) is also known as polyethylene oxide or PEO. It is a solid electrolyte that exhibits high chemical stability against the metal lithium.

[0038] The poly(ethylene oxide) is modified in the two layers 41, 42 by the additions lithium phosphorus sulfur chloride and lithium aluminum titanium phosphate, respectively.

[0039] The double-layer structure with the first layer 41 and the second layer 42 leads to higher stability, especially higher interface stability.

[0040] Anode 31 is designed as a lithium metal anode.

[0041] The lithium phosphorus sulfur chloride is preferably provided at least partially as Li6PS5Cl.

[0042] The lithium-aluminum-titanium phosphate is preferably at least partially available as Li 1.3 Al 0.3 Ti 1.7 (PO4)3 provided.

[0043] The lithium phosphorus sulfur chloride is preferably present in the form of nanoparticles.

[0044] The lithium-aluminum-titanium phosphate is preferably present in the form of nanoparticles.

[0045] The lithium-phosphorus-sulfur chloride preferentially exhibits a mass fraction between 0.02 and 0.07 in layer 41.

[0046] The lithium-aluminium-titanium phosphate preferably has a mass fraction between 0.10 and 0.25 in layer 42.

[0047] The respective mass fractions mentioned have proven to be advantageous for increasing ionic conductivity.

[0048] Preferably, the cathode 32 comprises at least one cathode material from a cathode material group consisting of: - Lithium iron phosphate (LFP), - Lithium nickel manganese cobalt oxide (NMC), and - Lithium nickel cobalt aluminum oxide (NCA).

[0049] The specific capacity of the battery cell 20 is preferably at least as large as at least one first specific capacity from a capacity group consisting of: - 156.3 mAh / g, and - 225 mAh / g.

[0050] The specific capacitance is the number of electrons absorbed or emitted per mass of the active electrode material.

[0051] The ionic conductivity of the asymmetric composite electrolyte 40 is preferably at least as large as at least one first ionic conductivity from an ionic conductivity group consisting of: - 3.00 · 10 -4 S / cm, and - 3.37 · 10 -4 S / cm.

[0052] High ionic conductivity can be achieved with the compound electrolyte 40. The increase in ionic conductivity is achieved in particular by the lithium phosphorus sulfur chloride and the lithium aluminum titanium phosphate.

[0053] In experiments with a current density of 0.2 mA cm -2 The battery cells 20 were operated stably and without short circuits for a period of 2,000 hours. This is significantly better than when using pure poly(ethylene oxide).

[0054] The asymmetric composite electrolyte 40 is preferably produced by a solution casting process. This enables good formation of the layers 41, 42.

[0055] The anodes 31 and the cathodes 32 are at least partially in contact on both sides with an asymmetric composite electrolyte 40. The first layer 41 always faces the anode 31, and the second layer 42 faces the cathode 32.

[0056] Such a battery 12 can also be called a solid-state lithium-metal battery (English: all-solid-state lithium-metal battery or ASSLMB).

[0057] The battery 12 or the battery cells 20 have a high energy density and good intrinsic safety.

[0058] In a process for manufacturing the battery cell 20, the asymmetric composite electrolyte 40 is produced by a solution casting process. This process is simple and easily scalable.

[0059] Naturally, various variations and modifications are possible within the scope of the present invention.

Claims

[1] Battery cell (20), comprising - an anode (31) which contains lithium metal, - a cathode (32), - an asymmetric composite electrolyte (40) with a first layer (41) and with a second layer (42), wherein the first layer (41) is in contact with the anode (31), wherein the second layer (42) is in contact with the cathode (32), wherein the first layer (41) comprises a lithium phosphorus sulfur chloride and a poly(ethylene oxide) as components, and wherein the second layer (42) comprises a lithium aluminum titanium phosphate and a poly(ethylene oxide) as components. [2] Battery cell (20) according to claim 1, wherein the anode (31) is designed as a lithium metal anode. [3] Battery cell (20) according to claim 1 or 2, wherein the lithium phosphorus sulfur chloride is at least partially provided as Li6PS5Cl. [4] Battery cell (20) according to one of the preceding claims, wherein the lithium aluminum titanium phosphate is at least partially configured as Li 1.3 Al 0.3 Ti 1.7 (PO4)3 is provided for. [5] Battery cell (20) according to one of the preceding claims, wherein the lithium phosphorus sulfur chloride is in the form of nanoparticles. [6] Battery cell (20) according to one of the preceding claims, wherein the lithium aluminum titanium phosphate is in the form of nanoparticles. [7] Battery cell (20) according to one of the preceding claims, wherein the lithium phosphorus sulfur chloride in the first layer (41) has a mass fraction between 0.02 and 0.

07. [8] Battery cell (20) according to one of the preceding claims, wherein the lithium aluminum titanium phosphate in the second layer (42) has a mass fraction between 0.10 and 0.

25. [9] Battery cell (20) according to one of the preceding claims, wherein the cathode (32) comprises at least one cathode material from a group of cathode materials consisting of: - Lithium iron phosphate (LFP), - Lithium nickel manganese cobalt oxide (NMC), and - Lithium nickel cobalt aluminum oxide (NCA). [10] Battery cell (20) according to one of the preceding claims, wherein the specific capacity of the battery cell (20) is at least as large as at least one first specific capacity from a capacity group consisting of: - 156.3 mAh / g, and - 225 mAh / g. [11] Battery cell (20) according to one of the preceding claims, wherein the ionic conductivity of the asymmetric composite electrolyte (40) is at least as large as at least one first ionic conductivity from an ionic conductivity group consisting of: - 3.00 · 10 -4 S / cm, and - 3.37 · 10-4 S / cm. [12] Battery cell (20) according to one of the preceding claims, wherein the asymmetric composite electrolyte (40) is produced by a solution casting process. [13] Battery (12) comprising at least one battery cell (20) according to any of the preceding claims. [14] Vehicle (10) comprising at least one battery (12) according to claim 13. [15] Method for producing a battery cell (20) according to any one of claims 1 to 12, wherein the asymmetric composite electrolyte (40) is produced by a solution casting process.

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