EP-4742304-A1 - METHOD FOR PRODUCING AN ELECTRODE STACK FOR A FLUORIDE-ION BATTERY

Abstract

The invention relates to a method for manufacturing an electrode stack for a fluoride-ion battery. The method comprises the following steps: a) Providing a metal foil which i) according to a first variant consists essentially of AI or ii) according to a second variant consists essentially of a metal selected from the group Ag, Cu and Fe; b) Coating one side of the metal foil with a fluoride-conducting solid electrolyte layer; and c) Coating the solid electrolyte layer with a further layer which i) according to the first variant consists essentially of a metal fluoride or a fluorinated metal foil of a metal selected from the group Ag, Cu and Fe or ii) according to the second variant consists of a metal fluoride or a fluorinated metal foil of Al.

Inventors

• OSTERWALD, Manfred

Assignees

• PrimeSolid Batteries GmbH

Dates

Publication Date

20260513

Application Date

20241106

Claims (6)

1. Method for manufacturing an electrode stack for a fluoride-ion battery, comprising the steps: a) Providing a metal foil which i) according to a first variant consists essentially of AI or ii) according to a second variant consists essentially of a metal selected from the group Ag, Cu and Fe; b) Coating one side of the metal foil with a fluoride-conducting solid electrolyte layer; and c) Coating the solid electrolyte layer with a further layer which i) according to the first variant consists essentially of a metal fluoride or a fluorinated metal foil of a metal selected from the group Ag, Cu and Fe or ii) according to the second variant consists of a metal fluoride or a fluorinated metal foil of Al.
2. Method according to claim 1, characterized in that the coating of the metal foil with the solid electrolyte layer in step b) is carried out by means of a printing process, in particular by means of flexographic printing.
3. Method according to one of the preceding claims, characterized in that the metal foil has electrical insulation on a side opposite the solid electrolyte layer.
4. Method according to claim 3, characterized in that the electrical insulation is an insulating film and is bonded to the metal foil to form a laminate before step a).
5. A method according to one of the preceding claims, characterized in that the electrode stack obtained by step c) is wound into an electrode coil. is formed, with the metal foil forming an outer surface of the electrode winding.
6. Method according to one of the preceding claims, characterized in that the solid electrolyte layer consists essentially of LaF 3 , BaF 2 or a mixture thereof.

Description

The invention relates to a method for manufacturing an electrode stack for a fluoride-ion battery. Technological background Modern life depends heavily on energy storage. From portable electronics to electric vehicles (EVs), electric trains, and airplanes, all benefit from modern rechargeable energy storage technologies. Energy storage is also needed for storing energy from solar, wind, and tidal power plants. Therefore, the demand for efficient and sustainable systems is increasing dramatically. Lithium-ion batteries (LIBs) have proven advantageous for portable electronic devices and suitable for electric vehicles due to their high energy density, specific power, and cycle stability. However, the diverse applications of LIBs could lead to the rapid depletion of lithium resources, which are scarce and geographically limited. Furthermore, not only are lithium deposits limited, but so are the deposits of other key elements (e.g., cobalt) used in LIBs. Therefore, there is a continuing need for alternative energy storage systems based on the transport of ions other than Li+, which could also lead to the use of other elements in the electrode materials. Alternatives to lithium-ion batteries (LIBs) have included sodium-ion batteries (NIBs), magnesium-ion batteries, calcium-ion batteries, and aluminum-ion batteries. In these systems, the migrating ions have low standard reduction potentials, similar to those of lithium. In contrast, the migrating ions in fluoride-ion batteries (FIBs) possess a very high standard reduction potential. FIBs can therefore potentially achieve higher gravimetric energy densities than, for example, rechargeable battery systems made of sodium and potassium-ion batteries. The volumetric energy density of FIBs is particularly high, which is of interest for electric vehicles and large-scale energy storage applications. Besides their high energy density, FIBs have other unique properties. Fluorine is the strongest oxidizing agent and the most electronegative element in the periodic table. Therefore, the fluoride ion is a very redox-stable anion, exhibiting a broad range of properties. This allows for an electrochemical potential window. Furthermore, fluoride-containing materials are available in larger quantities worldwide compared to lithium reserves. FIBs function on a similar principle to lithium-ion batteries, where ions migrate between positive and negative electrodes during charge and discharge cycles. The main difference lies in the type of ions involved: The anode is typically made of a material capable of absorbing and storing fluoride ions during the discharge phase. Materials such as metals can be used for the anode. The cathode consists of a material capable of releasing fluoride ions during the charging phase. Various materials, such as transition metal fluorides, can be used for the cathode. The electrolyte is crucial for the movement of fluoride ions between the anode and cathode. It must facilitate the transport of these ions while simultaneously ensuring stability during the electrochemical reactions. Solid-state electrolytes or ionic liquids can be used in fluoride-ion batteries. A separator prevents direct contact between the anode and cathode to avoid a short circuit while still allowing the passage of ions. During the basic electrochemical reactions of charging and discharging, fluoride ions move between the anode and cathode. Specific materials, electrolytes, and design details may vary depending on ongoing research and development of FIB technology. Solid-state batteries offer several advantages over liquid electrolyte batteries, particularly regarding safety. Solid electrolytes are required for their operation. Various fluoride-conducting solid electrolytes exist, exhibiting very high conductivities at room temperature. The solid electrolyte must be chemically compatible with the electrode materials (cathode and anode) to ensure rapid ion transport of charged species across the interfaces, which necessitates stability against redox reactions. Furthermore, solid electrolytes should possess certain mechanical properties, such as sufficient flexibility and softness, required for the fabrication of a solid-state battery. The literature describes... Various fluoride-conducting solid electrolytes have been described. These solid electrolytes can be roughly divided into two classes of compounds: the tysonite type (prototype LaF₃ ) and the fluorite type (prototype CaF₂ ). For example, metals such as Li, Mg and Na are proposed as anode materials, and transition metal fluorides of the elements Bi, Cu, Fe, Al, Co, Ti and Zn are suggested for the cathode. Currently, FIBs are manufactured manually in research and pre-development settings. However, industrial manufacturing techniques are crucial for widespread application. Most commonly, material powders have been compressed and various vapor deposition processes, such as PVD or CVD, have been used. None of these methods are suita