Search

CN-121986067-A - Novel method for embedding alkali metal into transition element-based material

CN121986067ACN 121986067 ACN121986067 ACN 121986067ACN-121986067-A

Abstract

The invention relates to a method for the solid-state alkalization of salts which contain at least one transition metal and are devoid of alkali metals, characterized in that it comprises the steps of a) mixing the salts devoid (or devoid of) alkali metals in solid form with the corresponding alkali metal iodides (which are also in solid form) to obtain a solid mixture, b) reacting said solid mixture to obtain molecular iodine and alkali metal-enriched transition metal salts, and optionally c) separating the molecular iodine from the solid mixture.

Inventors

  • Nadir Raycham
  • Tasadit Vanesh
  • Michele. Socrates
  • Lorenzo Stevano
  • Lor Mongondi
  • Claude Gary

Assignees

  • 法国国家科学研究中心
  • 亚眠大学
  • 法国蒙彼利埃大学
  • 法国国立蒙彼利埃高等化学学院

Dates

Publication Date
20260505
Application Date
20241002
Priority Date
20231003

Claims (10)

  1. 1. A process for the solid-state alkalization of a salt comprising at least one transition metal and partially or completely devoid of alkali metals, characterized in that it comprises the following steps: a) Mixing said alkali metal-deficient or alkali metal-free salt with the corresponding alkali metal iodide in solid form to obtain a solid mixture, said iodide also being in solid form; b) Reacting the solid mixture to obtain molecular iodine and a transition metal salt rich in the alkali metal, and, optionally, C) Separating molecular iodine from the solid mixture, Wherein the alkali metal-rich transition metal salt is selected to have an average potential of greater than 3V relative to lithium (Li + /Li 0 ) under normal pressure and temperature conditions in the solid state.
  2. 2. The method according to claim 1, wherein a heating step is performed during or after step a) and/or b), preferably at a temperature below 150 ℃, more preferably at a temperature below 100 ℃.
  3. 3. The method according to claim 1 or 2, wherein steps a) and/or b) are performed in ambient air or an inert atmosphere.
  4. 4. The method according to claim 1, wherein steps a) and/or b) are performed without heating and/or at ambient temperature, and preferably the method is performed without heating except for step c).
  5. 5. The method according to claim 1 or 4, wherein steps a) and/or b) are performed in the presence of air.
  6. 6. The method according to any one of claims 1 to 5, wherein the salt comprising at least one alkali metal and one transition metal is an electrochemically active compound, such as: An olivine salt of general formula XYTO 4 , wherein T is at least one tetravalent cation (in particular Si, P, as), X is at least one alkali metal cation, Y is at least one metallic non-alkali metal cation, or A compound of formula AM1 x M2 y M3 z O 2 , wherein x+y+z=1, a is an alkali metal, preferably Li and/or Na, M1, M2 and M3 are all non-alkali metals, preferably selected from the group consisting of metal ions Co 3+ 、Ni 3+ 、Mn 3+ 2、Al 3+ 、Fe 3+ 、V 3+ 、Cr 3+ 、Nb 3+ 、Mo 3+ .
  7. 7. The method according to any one of claims 1 to 6, wherein the compound comprising a transition metal and lacking an alkali metal is part of an electrode and/or is mixed with another component, such as a conductive agent, e.g. graphite, carbon black, carbon fibres and/or nanotubes, and/or a binder, e.g. polyvinylidene fluoride and/or polytetrafluoroethylene.
  8. 8. The method according to any one of claims 1 to 7, wherein the separation step c) is performed by washing the mixture with an organic solvent, such as an alcohol, e.g. ethanol, optionally followed by a drying step.
  9. 9. The process according to any one of claims 1 to 7, wherein the separation step c) is performed by heating the mixture under conditions allowing sublimation of molecular iodine, preferably in an inert atmosphere, such as in an Ar/N 2 gas flow, or in vacuum.
  10. 10. A method of recovering an electrochemically active material for use in a battery with charge transfer with alkali metal ions, comprising the steps described in the method of claims 1 to 9.

Description

Novel method for embedding alkali metal into transition element-based material Technical Field The present invention relates to a method for embedding or inserting alkali metals into transition element-based materials, which can be used for the synthesis or recovery of materials for battery cells and batteries, wherein the alkali metal elements used include sodium, lithium and potassium (i.e. solid state alkalization). Background The transition to the electric mode is currently one of the most important factors for reducing global carbon emissions. After the end of the service life of alkali metal-based batteries and accumulators, their disposal, recovery and recycling are increasingly urgent. In fact, the production of lithium batteries (also called lithium batteries or lithium ion batteries) continues to increase, and therefore, in the next few years, there will be an increasing number of batteries reaching the end of their useful life, requiring disposal. Therefore, it is important to properly recycle the waste water. This recycling relates in particular to a method for reintroducing alkali metal elements into the electrode material, in particular materials used in devices for exchanging these alkali metal ions, in particular lithium, potassium and sodium ions. There are a number of known lithiation pathways for alkali metal electrode materials: i) The heat treatment was performed at 700℃for 10 hours under an argon atmosphere after adding a lithium source (Li 2CO3) and a reducing agent (C) to the delithiated phase (FePO 4). 1,2 This is not direct lithiation of FePO 4, but rather a complementary high temperature synthesis of the material, as the process involves chemical reaction of Li 2CO3 with the product of FePO 4 after carbon reduction; ii) electrochemical lithiation 3 by graphite prelithiation. The method needs to be carried out under a controllable atmosphere, has high cost and is difficult to apply on a large scale; iii) Chemical lithiation, i.e., dissolving lithium iodide (LiI) in an organic solvent (acetonitrile, ethanol, cyclohexane, DMSO, etc.), and then contacting 4,5,6 with a positive electrode material at the end of life (including FePO 4 and LiFePO 4). The process is slow in kinetics (about 20 hours) and uses large amounts of solvent, which is not very compatible with the requirements of an environmentally friendly process. It is also known that sodium metal is used for sodium modification of Na 3V2(PO4)2F3 to Na 4V2(PO4)2F3.7 by mechanical ball milling with sodium metal as a reducing agent, requiring special and costly safety precautions (argon/drying chamber). Thus, there is a need for an easy to implement, low cost and/or environmentally friendly method allowing the synthesis and/or reintroduction of alkali metal ions into compounds containing transition elements, in particular compounds intended for and/or used in the electrochemical manufacture of electrodes. Disclosure of Invention It is therefore an object of the present invention to provide a process for the solid-state alkalization of a compound (in particular a salt containing at least one transition metal), said compound being devoid of alkali metals, characterized in that it comprises the following steps: a) Mixing said alkali metal deficient (or non-alkali metal containing) salt with a corresponding alkali metal iodide in solid form, which iodide is also in solid form, to give a solid mixture; b) Reacting the solid mixture to obtain molecular iodine and a transition metal salt rich in the alkali metal, and, optionally, C) Separating molecular iodine from the solid mixture, Wherein the alkali metal-rich transition metal salt is preferably selected such that the average potential relative to lithium (Li +/Li) under normal pressure and temperature conditions in the solid state is greater than 3V. It is particularly advantageous that the process can either prepare the alkali metal salt of the transition metal from a salt which is completely free of alkali metal or increase the content of the alkali metal in the transition metal salt which already contains a small amount of alkali metal. Thus, "solid state alkalization" refers to both the synthesis of alkali metal salts and the increase of the alkali metal content of salts already partially containing alkali metals. Thus, the process of the present invention may be either a process for synthesizing an alkali metal salt or a process for regenerating, recovering and/or inserting alkali metal ions into a transition metal-containing material. The term "salt" refers in its modern sense to ionic solids, i.e. networks of ions of different charge. It is no longer limited by the solubility, appearance, and flammability properties that have been previously associated with this term. The term "lacking" refers not only to unsaturated compounds containing a particular alkali metal, but also to compounds that do not contain that alkali metal. Likewise, the term "enriched" refers not only to satur