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EP-4741363-A1 - CONTAINER FOR CATHODE ACTIVE MATERIALS

EP4741363A1EP 4741363 A1EP4741363 A1EP 4741363A1EP-4741363-A1

Abstract

A process for manufacturing a batch container for calcining lithium-containing cathode active material is available, a process involving the forming and sintering of - 40 to 70% by mass of andalusite - 5 to 20% alumina - 0 to 25% by mass of melt mullite - 0 to 25 MA.-% sintered spinel - 0 to 15% by mass of other minerals at temperatures below 1370 °C.

Inventors

  • SCHÄFER, Anna-Lena
  • Kalb, Christopher
  • SPERBER, Jens

Assignees

  • Steuler-KCH GmbH

Dates

Publication Date
20260513
Application Date
20241111

Claims (10)

  1. Method for manufacturing a batch container for calcining lithium-containing cathode active material comprising the shaping and sintering of - 40 to 70% by mass of andalusite - 5 to 20% alumina - 0 to 25% by mass of melt mullite - 0 to 25 MA.-% sintered spinel - 0 to 15% by mass of other minerals at temperatures below 1370 °C.
  2. Method according to claim 1, wherein the amount of andalusite is 45 to 55% by mass.
  3. Method according to claim 1 or 2, wherein the andalusite has a d50 vol grain size of less than 1 mm or less than 0.5 mm.
  4. Method according to any one of claims 1 to 3, wherein the amount of molten mullite is 0 to 15% by mass.
  5. Method according to any one of claims 1 to 4, wherein the further minerals are selected from clay, magnesite, magnesium oxide.
  6. Method according to any one of claims 1 to 5, wherein the sintering takes place at temperatures below 1350 °C or below 1250 °C.
  7. Method according to any one of claims 1 to 6, wherein the forming is carried out with a pressure of at least 10 MPa.
  8. Batch containers for calcining lithium-containing cathode active material obtainable by the method according to any one of claims 1 to 7.
  9. Batch container for calcining lithium-containing cathode active material comprising at least 40 wt% andalusite.
  10. Use of andalusite as a component of a batch container for calcining lithium-containing cathode active material

Description

The present invention relates to a method for producing a batch container and the batch container thus obtained. Cathode active materials for lithium batteries consist of lithium-ion cells. These comprise anodes and cathodes, with the cathodes consisting of lithium transition metal compounds. Such compounds are often nickel-manganese-cobalt oxides and follow the general formula Li mn (Ni X Mn Y Co1 -xy )O 2 . To produce these materials, they are calcined from a precursor powder and a lithium source at approximately 650 to 1,000 °C. The calcined material is then used in the lithium-ion cell. The problem is that the containers in which the calcination takes place (batch containers) have to be replaced after only a few cycles because chips appear on the container and adhere to the cathode materials. This contaminates the cathode materials, rendering them of poor quality or unusable. The batch containers must exhibit high temperature stability and withstand temperature fluctuations. There are numerous other requirements. Although a wide variety of batch containers are known, there is still a need for batch containers that at least partially overcome the disadvantages of the state of the art and, for example, allow a higher number of cycles. The problem is solved by a process for manufacturing a batch container for calcining lithium-containing cathode active material by forming and sintering 40 to 70% by mass of andalusite 5 to 20% alumina 0 to 25% by mass of melt mullite 0 to 25% by mass sintered spinel 0 to 15% by mass of other minerals at temperatures below 1370 °C. According to the invention, a material is provided which contains andalusite and alumina as its main components. Andalusite is an nesosilicate from the group of aluminosilicates and has the chemical composition Al₂ [O| SiO₄ ]. Andalusite is also known in the production of refractory building and construction materials, but is usually fired at such high temperatures that the andalusite sinters and is thereby transformed into mullite. The preferred amount of andalusite is 45 to 55 wt%. A suitable andalusite grain size is < 0.5 mm, measured as d50 vol . d50 vol means that 50% of the material has a grain size larger than the corresponding value and 50% has a smaller grain size. Such grain size distributions can be determined using sieve curves. Preferably, they are measured by laser diffraction and then calculated. Clay is a mineral with the general formula Al₂O₃. Clay occurs in various crystal systems. All forms are suitable for the batch container according to the invention. The starting material for the production of the batch container may contain other substances. One possible substance is molten mullite. Mullite is a mineral from the silicate and germanate group and belongs to the nesosilicates. Molten mullite has the composition 2Al₂O₃ · 1SiO₂ and contains a glassy phase . Molten mullite is typically produced by melting a mixture of kaolinite. and aluminum oxide. Mullite is used as a component in the production of porcelain, bricks, and firebricks. Another possible component is sintered spinel. Spinels are magnesium aluminates. They have the general formula MgAl₂O₄ . Due to its high hardness and chemical resistance , as well as its high melting point of 2135 °C, sintered spinel is used for refractory and gas-tight technical ceramics. Suitable sintered spinels are found, for example, in EP 3 458 430 B1 described. Furthermore, the batch container can, in principle, contain other minerals. Examples include clay, magnesite, and magnesium oxide. In this case, clay refers to layered silicates, which have layered crystal structures made of silicon, oxygen, and possibly hydrogen, magnesium, and aluminum. Magnesite is a mineral with the general chemical composition MgCO3 . Magnesite is frequently used in the production of refractory materials. Another possible component is magnesium oxide. Magnesium oxide is also used in the production of refractory materials. A key aspect of the process according to the invention is that the sintering temperature is relatively low. According to the invention, it is at least below 1370 °C, preferably below 1350 °C or below 1330 °C, and even more preferably below 1300 °C or below 1250 °C. These temperatures ensure that the andalusite retains its properties. The batch containers require a mold suitable for the production of the cathode materials. The powders are therefore first shaped and preferably solidified under pressure. A pressure of at least 10 MPa, preferably 20 MPa, is preferred. The invention also relates to a batch container for calcining lithium-containing cathode active materials, which is obtainable by the process according to the invention. This container comprises at least 40 wt% andalusite. The invention also relates to the use of andalusite as a component of a batch container for calcining lithium-containing cathode active materials. The invention is explained in more detail by the following examples: