Method for producing a rechargeable battery using spent cathode active material

Abstract

The invention relates to a method for producing a rechargeable alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery using spent cathode active material from at least one spent alkaline ion battery or alkaline earth ion battery. The invention also relates to a battery produced according to this method.

Description

[0001] The invention relates to a method for producing a rechargeable alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery using cathode active material from used alkaline-ion batteries or alkaline earth-ion batteries. The invention also relates to a rechargeable battery.

[0002] Batteries that use alkaline or alkaline earth ions as charge carriers are indispensable as electrical energy storage devices in many technical fields. Alkaline-ion batteries, especially lithium-ion batteries, are the most commercially widespread and have proven their worth, for example, as energy storage devices for electric vehicle propulsion and in electronics. In addition, alkali metal-metal hybrid batteries and alkaline earth metal-metal hybrid batteries are also known, in which ions of another metal contribute to charge transport in addition to alkaline or alkaline earth ions.

[0003] The batteries mentioned are based on the principle that, during discharge, alkali ions (or alkaline earth ions) are reversibly stored in a so-called cathode active material, and these ions are released from the cathode active material again when the battery is charged.

[0004] With the increasing prevalence of these batteries, their recycling is also becoming more of a focus.

[0005] From DE 10 2016 200 079 A1 an electrolyte material for a particularly lithium-containing electrochemical cell is described, comprising an electrolyte material based on an organic solvent or a polymer and at least one conducting salt, wherein a perfluoroalkoxylate is provided as the conducting salt.

[0006] Furthermore, a method and a device for recycling positive and negative electrode materials from lithium-ion batteries are known from CN 1 19 725 834 A.

[0007] The invention addresses the problem of reusing and / or providing the starting materials of the aforementioned batteries in a simple and economical way.

[0008] This problem is solved according to the invention by a method having the features of claim 1 and by a battery cell having the features of claim 18.

[0009] According to a first aspect, a method for producing a rechargeable battery, in particular an alkali metal-metal hybrid battery or an alkaline earth metal-metal hybrid battery, preferably a lithium metal hybrid battery, is proposed using, in particular, used cathode active material from, in particular, used alkali-ion batteries or alkaline earth-ion batteries, especially lithium-ion batteries. The method comprises providing at least one positive electrode comprising used cathode active material, in particular depleted in alkali metal ions or alkaline earth metal ions, from used alkali-ion batteries or alkaline earth-ion batteries, especially lithium-ion batteries. The method further comprises providing at least one negative electrode. The method also comprises providing a starting electrolyte.The method further comprises arranging the at least one positive electrode, the at least one negative electrode, and the initial electrolyte such that the at least one positive electrode and the at least one negative electrode are in contact with the initial electrolyte. The method also comprises manufacturing a battery cell from the at least one positive electrode, the at least one negative electrode, and the initial electrolyte such that the at least one positive electrode and the at least one negative electrode are in contact with the initial electrolyte.

[0010] In the proposed method, used cathode active material from used alkaline-ion batteries or alkaline earth-ion batteries is (re)used as electrode material in a different type of battery, namely an alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery.

[0011] Therefore, the use of used cathode active material from used alkaline-ion batteries or alkaline earth-ion batteries, especially lithium-ion batteries, as electrode material in an alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery is also proposed.

[0012] The used cathode active material is designed to reversibly absorb, release, and reabsorb ions of a first metal. The first metal is an alkali metal, in particular lithium, or an alkaline earth metal. Preferably, the first metal is lithium.

[0013] In this context, "used alkaline-ion battery" or "alkaline earth-ion battery" refers in particular to an alkaline-ion battery or an alkaline earth-ion battery whose capacity is less than its original capacity, specifically an alkaline-ion battery or an alkaline earth-ion battery whose capacity is at most 80%, preferably at most 70%, more preferably at most 60%, and more preferably at most 50%, of its original capacity. Therefore, the capacity of the used alkaline-ion battery or an alkaline earth-ion battery may have decreased by at least 20% compared to its original capacity. The used alkaline-ion battery or an alkaline earth-ion battery may be an "end-of-life" battery.

[0014] "Used cathode active material" refers to cathode active material from a used, i.e., previously used, alkaline-ion or alkaline earth-ion battery. Specifically, the used cathode active material is depleted of ions of the first metal; that is, the content of ions of the first metal incorporated into the cathode active material is lower than the content of ions of the first metal in the cathode active material in an unused (fresh) state (and consequently, the capacity of the used cathode active material is lower than the capacity of the unused (fresh) cathode active material).Preferably, the content of ions of the first metal incorporated into the cathode active material in the used cathode active material is a maximum of 80%, preferably a maximum of 70%, further preferably a maximum of 60%, further preferably a maximum of 50%, of the content of ions of the first metal in the cathode active material in an unused (fresh) state.

[0015] The positive electrode, in particular the cathode, comprises a first electrode material which contains or consists of the spent cathode active material. The first electrode material of an alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery may contain spent cathode material from one or more alkaline ion batteries or alkaline earth ion batteries.

[0016] The negative electrode, in particular the anode, comprises a second electrode material, in particular a metallic one (anode material). The second electrode material contains or consists of a second metal, different from the first. The second metal is a metal selected from the group consisting of magnesium, aluminum, and the transition metals. Preferably, the second metal is zinc. This can therefore be a method for manufacturing an alkali metal-zinc hybrid battery or an alkaline earth metal-zinc hybrid battery, in particular a lithium-zinc hybrid battery.

[0017] The starting electrolyte contains at least one salt of the first metal. The starting electrolyte also contains at least one salt of the second metal. The starting electrolyte contains at least one solvent, in particular water, organic solvents, or mixtures thereof.

[0018] The manufacture of the battery cell includes arranging the positive electrode, the negative electrode and the initial electrolyte in such a way that the first electrode material and the second electrode material are in contact with the initial electrolyte, in particular immersed in the initial electrolyte.

[0019] The process preferably also includes carrying out a re-metallization step, in particular a re-lithiation step, after the battery cell has been manufactured, in order to increase the number of alkali metal ions or alkaline earth metal ions incorporated into the used cathode active material. In this respect, the "regeneration" of the used cathode active material only takes place after the battery cell has been manufactured. Specifically, prior to this re-metallization step after the battery cell has been manufactured, no active re-metallization of the used cathode active material occurs, i.e., no active incorporation of ions of the first metal into the used cathode active material. This simplifies the recycling process.

[0020] The re-metallization step includes, in particular, at least partially discharging the battery cell. Therefore, a discharge process can be carried out after the battery cell has been manufactured. This discharge is performed in such a way that ions of the first metal from the initial electrolyte (depleting the initial electrolyte of the first metal) are incorporated into the cathode active material. It has proven advantageous to discharge the battery cell at a C-rate (also referred to as C-rating or C-coefficient) between 0.2C and 2C. In particular, the re-metallization can be carried out during the first discharge process of the battery.

[0021] The proposed method makes it possible to reuse spent cathode active material from alkaline-ion or alkaline earth-ion batteries and to economically manufacture batteries with comparatively good properties – in particular without the need for complex regeneration processes of the cathode active material before its installation in the battery cell. This provides a simple and economical solution for recycling cathode active material from alkaline-ion or alkaline earth-ion batteries.

[0022] Preferably, the first metal is lithium. Accordingly, a method for producing a lithium-metal hybrid battery using spent cathode active material from used lithium-ion batteries is also proposed. This method then comprises, in particular, the following steps: - Providing a positive electrode, in particular a cathode, comprising a first electrode material, wherein the first electrode material contains or consists of cathode active material from used lithium-ion batteries; - Providing a negative electrode, in particular anode, comprising a second electrode material, wherein the second electrode material contains or consists of a second metal other than lithium, wherein the second metal is selected from the group consisting of magnesium, aluminium and transition metal, preferably zinc; - Providing a starting electrolyte, comprising ◯ at least lithium salt, especially LiCl; ◯ at least one salt of the second metal, in particular a zinc salt, further in particular ZnCl2; ◯ at least one solvent, in particular water, organic solvents or mixtures thereof; - Manufacturing a battery cell from the positive electrode, the negative electrode and the initial electrolyte, wherein the first electrode material and the second electrode material are in contact with the initial electrolyte; - optional: Performing a re-lithiation step after manufacturing the battery cell to increase the number of lithium ions incorporated into the used cathode active material, in particular wherein the re-metallization step includes at least partially discharging the battery cell, further in particular such that lithium ions from the initial electrolyte are incorporated into the used cathode active material.

[0023] It is particularly preferred if the first metal is lithium, the used cathode active material is lithium iron phosphate from used lithium-ion batteries, and the second metal is zinc. Positive electrode:

[0024] The following are advantageous further developments of the procedure with regard to the positive electrode: Preferably, the proportion of the used cathode active material in the first electrode material is at least 70 wt.%, preferably at least 80 wt.%, further preferably at least 90 wt.%, based on a total weight of the first electrode material.

[0025] The provision of the positive electrode, especially the first electrode material, may involve several sub-steps.

[0026] In particular, providing the positive electrode, especially the first electrode material, includes providing raw cathode material from at least one used alkaline-ion battery or alkaline earth-ion battery, wherein the raw cathode material contains the used cathode active material. Providing the positive electrode then specifically includes further processing the raw cathode material into the first electrode material.

[0027] The raw cathode material is, in particular, cathode material removed, especially mechanically, from a used alkaline-ion battery or alkaline earth-ion battery. Therefore, providing the raw cathode material can include removing cathode material from the used alkaline-ion battery or alkaline earth-ion battery. Providing the positive electrode preferably includes further processing the raw cathode material into the first electrode material.

[0028] The raw cathode material may contain at least one binder in addition to the used cathode active material. This binder may be, for example, polyvinylidene fluoride (PVDF), polytetrafluoroethylene (PTFE), polyethylene (PE), polyurethane (PU), or combinations thereof.

[0029] In addition to the used cathode active material and the optional binder, the raw cathode material may contain at least one carbon material. This carbon material may, in particular, be carbon black.

[0030] Preferably, during the further processing of the crude cathode material into the first electrode material, the at least one binder and the optional carbon material contained in the crude cathode material are not removed, or at least not to more than 10 wt.% based on an initial content of the binder or carbon material in the crude cathode material. This process thus makes it possible to reuse crude cathode material without complex purification steps.

[0031] The raw cathode material can be used as the first electrode material without any further additives. Therefore, the first electrode material can comprise or consist of raw cathode material from used alkaline-ion batteries or alkaline earth-ion batteries.

[0032] One or more further additives may be added to the raw cathode material before its use in the alkaline metal-metal hybrid battery or alkaline earth metal hybrid battery. In this respect, the provision of the first electrode, in particular the first electrode material, may further include, in particular, the processing of the raw cathode material and the addition of at least one additive to the raw cathode material. The first electrode material may therefore comprise raw cathode material and at least one additive.

[0033] The at least one additive may comprise a binder. In this respect, the provision of the first electrode, in particular the first electrode material, may further, in particular, the processing of the crude cathode material, including the addition of at least one binder to the crude cathode material. The at least one binder may, in particular, be selected from the group consisting of PVDF (polyvinylidene fluoride), PTFE (polytetrafluoroethylene), PU (polyurethane), CMC (carboxymethylcellulose), SBR (styrene-butadiene rubber), PAA (polyacrylic acid), PVA (polyvinyl akhocol), and combinations thereof. In this respect, the first electrode material may, in addition to the used cathode active material, comprise at least one binder, in particular selected from the group consisting of PVDF, PTFE, PU, ​​CMC, SBR, PAA, PVA, and combinations thereof.

[0034] The at least one additive can comprise an electrically conductive component. In this respect, the provision of the first electrode, in particular the first electrode material, and further, in particular, the further processing of the crude cathode material, can—in addition to or as an alternative to the addition of at least one binder—comprise the addition of at least one electrically conductive component to the crude cathode material. The electrically conductive component is preferably a carbon component, further preferably selected from the group consisting of carbon black, carbon black, graphite, carbon nanotubes, and combinations thereof. Carbon black has proven to be particularly advantageous.Therefore, in addition to the cathode active material used and the optional at least one binder, the first electrode material can have at least one electrically conductive component, in particular a carbon component, and further in particular carbon black, graphite, carbon nanotubes or combinations thereof.

[0035] The positive electrode can also comprise an electrically conductive support material, in particular a current collector plate, on which the first electrode material is applied. Therefore, providing the positive electrode can include providing an electrically conductive support material, in particular a current collector plate. Providing the positive electrode then preferably also includes applying a layer of the first electrode material to the support material.

[0036] The substrate material can be a metallic substrate, in particular aluminum, stainless steel, nickel, or titanium. The substrate material can also be a carbon material, in particular graphite, further specifically graphite felt, graphite sheet, or graphite foil.

[0037] Preferably, the mass loading of the used cathode active material on the support material is more than 20 mg / cm². 2 , preferably between 50 mg / cm² 2 and 150 mg / cm² 2 , preferably between 75 mg / cm² 2 and 125 mg / cm² 2 Therefore, the application of a layer of the first electrode material onto the substrate material can be carried out in such a way that the mass loading of the used cathode active material on the substrate is more than 20 mg / cm². 2 , preferably between 50 mg / cm² 2 and 150 mg / cm² 2 , preferably between 75 mg / cm² 2 and 125 mg / cm² 2 amounts.

[0038] In a first advantageous implementation, the application of the layer of the first electrode material onto the support material can include the preparation of a suspension comprising the used cathode active material and the deposition of the suspension onto the support material.

[0039] Preferably the suspension contains: - the used cathode active material, in particular raw cathode material; - if necessary, at least one binder, in particular selected from the group consisting of PVDF, PTFE, PU, ​​CMC, SBR, PAA, PVA and combinations thereof; - optionally at least one electrically conductive component, in particular a carbon component, soot, carbon black, graphite, carbon nanotubes or combinations thereof; - at least one solvent, in particular selected from the group consisting of water, alcohols, acetone, NMP (N-methyl-2-pyrrolidone), DMSO (dimethyl sulfoxide), DMF (dimethylformamide) and combinations thereof.

[0040] It has proven advantageous if the solid content of the suspension is 25-90 wt.%, in particular 35-75 wt.%, and further in particular 55-65 wt.%, based on the total weight of the suspension.

[0041] In a second advantageous embodiment, the provision of the positive electrode can comprise the provision of a powder made from the used cathode active material, in particular the crude cathode material, optionally the at least one binder and optionally the at least one electrically conductive component, and the pressing of this powder into a pressed body. Negative electrode:

[0042] The following are advantageous further developments of the procedure with regard to the negative electrode: The negative electrode can have or consist of a foil made of the second electrode material, particularly a self-supporting one. Specifically, the negative electrode can have or consist of a metal foil made of the second metal.

[0043] Alternatively, the negative electrode can have a substrate made of a substrate material onto which a layer of the second electrode material, in particular the second metal, is applied. The layer of the second electrode material can be applied to one or both sides of the substrate material.

[0044] The substrate can be a flat material, in particular a film. The substrate material is preferably a metal or metal alloy or graphite. In particular, the substrate material can be selected from the group consisting of Cu, Ti, Ni, Sn, Al, stainless steel, graphite and combinations thereof.

[0045] The layer of the second electrode material can be a powder layer comprising a powder of the second metal. In this case, the second electrode material can, in particular, contain a binder, for example, a binder selected from the group consisting of PVDF (polyvinylidene fluoride), SBR (styrene-butadiene rubber), PTFE (polytetrafluoroethylene), and CMC (carboxymethylcellulose).

[0046] The layer made of the second electrode material can also be a thin film deposited physically (e.g. by gas phase deposition) or chemically (e.g. by electroplating). Cathode active material:

[0047] The following are advantageous further developments of the process with regard to the cathode active material used: The used cathode active material can have the composition A n M' a M" b M"' c M"" d O e exhibit, whereby: - A is a metal selected from the group formed by the metals of groups 1, 2 and 13 of the periodic table of elements, where A is different from M', M", M''', and M""; - M is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M' is different from A, M", M" and M''''; - M" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M" is different from A, M', M" and M''''; - M'" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M'" is different from A, M', M" and M''''; - M'"' is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M"" is different from A, M, M" and M'"; - a + b + c + d = 1, a ≥ 0, b ≥ 0, c ≥ 0, d ≥ 0, e > 0; - n > 0 and preferably n < 1.

[0048] A is preferably lithium. Therefore, the cathode active material used can have the composition Lin M' a M'' b M''' c M'''' d O e exhibit.

[0049] Alternatively, the used cathode active material can be a Prussian blue analogue, in particular of composition A n M' a M" b [Fe(CN)6]·mH2O, in this composition A n M' a M" b [Fe(CN)6]·mH2O are: - A a metal selected from the group formed by the metals of groups 1, 2 and 13 of the periodic table of elements, where A is different from M' and M"; - M' is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M' is different from A and M"; - M" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M" is different from A and M'; - a + b = 1, a ≥ 0, b ≥ 0; - m ≥ 0 - n > 0 and preferably n < 1.

[0050] A is preferably lithium. Therefore, the cathode active material used can have the composition Li n M' a M" b exhibit [Fe(CN)6]·mH2O.

[0051] In an advantageous embodiment, the first metal can be lithium, wherein the used The cathode active material selected is from the group consisting of Lithium iron phosphate, Lithium manganese iron phosphate, lithium-nickel-manganese-cobalt oxide, Lithium cobalt(III) oxide, Lithium nickel cobalt aluminum oxide, Berlin Blue analogues, especially those of the composition Li n M[Fe(CN) 6] with n > 0 and preferably n < 1 and M = Fe, Co, Ni, Cu, or Mn, and combinations thereof.

[0052] In particular, the used cathode active material may have one of the following compositions: - Li n FePO4; - Li n Mn x Fe y PO4, where x + y = 1; - Li n Ni x Mn y Co z O2, where x + y + z = 1; - Li n CoO2; - Li n Ni x Co y Al z O2, where x+ y+ z = 1; - Li n M[Fe(CN)6], where M is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, in particular where M is selected from the group consisting of Fe, Co, Ni, Cu, and Mn; where x, y and z are independently numbers greater than or equal to zero and where n > 0 and preferably n < 1.

[0053] Preferably, the first metal is lithium and the cathode active material used is lithium iron phosphate (also called LFP), in particular of the composition Li n FePO4 with n > 0 and preferably n < 1.

[0054] In another exemplary embodiment, the first metal can be sodium. The cathode active material used can then have, in particular, one of the following compositions: - N / a n FePO4; - N / a 4n Fe7(PO4)6; - N / a nM[Fe(CN)6], wherein M is at least one element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, in particular wherein M is selected from the group consisting of Fe, Co, Ni, Cu, Mn and combinations thereof; - N / a n MO2, wherein M is at least one element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, in particular wherein M is selected from the group consisting of Fe, Mn, Cr, Cu, V, Ni, Al, Co and combinations thereof; where n > 0 and preferably n < 1.

[0055] Exemplary cathode active materials of the composition Na n MO2 include Na 2 / 3 Fe 1 / 2 Mn 1 / 2 O2 and Na 2 / 3 Ni 1 / 3 Mn 2 / 3 O2.

[0056] In another exemplary embodiment, the first metal can be potassium. Then the cathode active material used can be, in particular, a Prussian blue analogue with the composition K n M[Fe(CN)6], wherein n > 0 and preferably n < 1 and wherein M is at least one element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, in particular wherein M is selected from the group consisting of Fe, Co, Ni, Cu, Mn, and combinations thereof. Starting electrolyte

[0057] The following are advantageous further developments of the process with regard to the starting electrolyte: In this context, the term "initial electrolyte" refers to the electrolyte in its initial composition, i.e., in particular before the re-metallization step. The initial electrolyte, especially the concentration of metal ions in the electrolyte, changes, particularly during the re-metallization step.

[0058] The at least one salt of the first metal can be, in particular, a chloride, a sulfate, a nitrate, an acetate, a perchlorate, or an organic salt.

[0059] The advantageous concentration of at least one salt of the first metal in the starting electrolyte (i.e., in the case of a single salt, the concentration of that salt in the starting electrolyte, and in the case of combinations of different salts, the total concentration of these salts in the starting electrolyte) can be between 0.5 mol / l and 4 mol / l.

[0060] Preferably, the concentration of at least one salt of the first metal in the starting electrolyte is calculated according to the following formula: c=mCAMCCAM(1−XCAM)VElnMe1+F+c0nMe1+ where: - m CAM the total mass of the cathode active material used in the battery cell; - C CAM the gravimetric capacity of the cathode active material is (e.g. 150 mAh / g for lithium iron phosphate and 200 mAh / g for NMC) - X CAM The concentration of ions of the first metal incorporated in the used cathode active material is divided by the concentration of ions of the first metal incorporated in the unused (fresh) state of the cathode active material (i.e., the original concentration of ions of the first metal in the unused cathode active material). CAMFor example, it is 0.5 for cathode active material from used batteries whose capacity is still 50% of the battery's original capacity. - V El the volume of the electrolyte; - n Me1+ the number of ions of the first metal in the salt (e.g. n Mel+1 = 2 when using Me12SO4 (e.g. Li2SO4 and n Me1+ = 1 when using Me1Cl (e.g. LiCl)); - F is the Faraday constant; - c0 is between 0.5 mol / l and 1 mol / l. For lithium iron phosphate as the cathode active material, c0 is preferably 0.5 mol / l in water. Preferably, c0 is a concentration of the ions of the first metal that is minimally required for the incorporation of the ions of the first metal into the cathode active material.

[0061] A starting electrolyte with such a concentration has proven advantageous for achieving effective regeneration of the spent cathode active material (i.e., the incorporation of ions of the first metal into the cathode active material) during the re-metallization step. In particular, the starting electrolyte contains a relatively high concentration of ions of the first metal, which are then incorporated into the cathode active material during the re-metallization step, thereby depleting the starting electrolyte.

[0062] The salt of the second metal can be, in particular, a chloride, a sulfate, a nitrate, an acetate, a perchlorate, an organic salt, or combinations thereof.

[0063] In a first exemplary implementation, the first metal can be lithium, the salt of the first metal lithium chloride (LiCl), the second metal zinc, and the salt of the second metal zinc chloride (ZnCl₂). In such a configuration, it can be advantageous if the concentration of lithium chloride in the starting electrolyte is between 0.5 mol / L and 3.5 mol / L, and the concentration of zinc chloride in the starting electrolyte is between 1 mol / L and 4.5 mol / L. Exemplary compositions of the starting electrolyte include 2.5–3.5 mol / L LiCl and 1.5–2.5 mol / L ZnCl₂, 1.5–2.5 mol / L LiCl and 2.5–3.5 mol / L ZnCl₂, and 0.5–1.5 mol / L LiCl and 3.5–4.5 mol / L ZnCl₂.

[0064] The solvent of the starting electrolyte can be selected, in particular, depending on the redox potential of the second metal.

[0065] For example, water has proven to be an advantageous solvent for configurations where the second metal has a more positive electrode potential than hydrogen (derived from the standard reduction potential for the given electrolyte composition with respect to salt concentration, pH, temperature, etc.), e.g., Zn, Mn, Cr, and Ni.

[0066] In configurations where the second metal is a metal that exhibits a more negative electrode potential than hydrogen, particularly under all possible aqueous electrolyte compositions (metal concentration, pH value, temperature, etc.), organic solvents have proven especially advantageous. For example, organic solvents such as tetrahydrofuran (THF), dimethoxyethane (DME), and 1,3-dimethyl-2-imidazolidinone (DMI) have proven useful.

[0067] The starting electrolyte may optionally contain, in addition to the salt from the first metal, the salt from the second metal and at least one solvent, one or more of the following additional components: - Buffer, e.g. acetic acid / acetate buffer, especially at pH 3.6-5.6; - Viscosity control agents, in particular gelling agents, e.g. polyethylene glycol (PEG), polyacrylic acid (PAA), carboxymethylcellulose (CMC), polyvinyl alcohol (PVA); - Co-solvents, e.g., methanol, ethanol, isopropanol, PEG, - Additives for controlling the electrodeposition of the second metal, e.g. sodium lauryl sulfate, benzyltriethylammonium chloride for Zn anode, - Additives to increase conductivity (e.g., other salts) Battery cell structure:

[0068] The following are beneficial further training opportunities regarding the structure of the battery cell: Preferably, the battery cell comprises a housing in which the at least one positive electrode, the at least one negative electrode, and the initial electrolyte are contained. In this respect, the step of manufacturing the battery cell can comprise providing a housing and arranging the at least one positive electrode, the at least one negative electrode, and the initial electrolyte within the housing.

[0069] The housing can be flexible and deformable. The housing can be rigid. The housing can be cylindrical. The housing can be cuboid.

[0070] According to a further advantageous embodiment, several negative electrodes and several positive electrodes can be provided. The negative electrodes and the positive electrodes can then be arranged alternately during the manufacture of the battery cell.

[0071] Preferably, a separator is arranged between each positive electrode and an adjacent negative electrode. The separator can be of various designs. It can be made of a nonwoven fabric, a membrane, a woven fabric, a knitted fabric, an organic material, an inorganic material, or a combination thereof.

[0072] The electrodes can be formed in a planar form, i.e., as layers with a thickness that is smaller in relation to their surface area.

[0073] The electrodes can be stacked. Therefore, manufacturing the battery cell can involve stacking the positive and negative electrodes.

[0074] The electrodes can be wound. Therefore, the arrangement of the positive and negative electrodes can include winding the electrodes. In particular, the battery cell can be designed as a wound cell. In this case, it can be advantageous for the housing to be cylindrical. In configurations with a separator, the electrodes can be wound together with the separator.

[0075] The battery cell can also be designed as a pouch cell (also known as a pouch bag cell or coffee bag cell). In this case, the casing can be flexible. For example, the casing can be a pouch made of a foil, particularly one based on aluminum.

[0076] According to a second aspect, an alkali metal-metal hybrid battery or alkaline earth metal hybrid battery is proposed, which is manufactured according to one of the methods described above.

[0077] The advantages and optional features described above with regard to the method and in particular with regard to the positive electrode, the negative electrode, the cathode active material and the starting electrolyte can also serve to design the battery according to the second aspect, so that, to avoid repetition, reference is made to the above disclosure in this regard.

[0078] According to a third aspect, the use of a battery according to the second aspect is proposed for the energy supply of a consumer.

[0079] The invention will be explained in more detail below with reference to the figures and several examples.

[0080] They show: Fig. 1 simplified schematic representation to illustrate a first exemplary arrangement of the electrodes; Fig. 2 simplified schematic representation to illustrate a second exemplary arrangement of the electrodes; Fig. 3 Characteristic curve to illustrate a first test cycle of a battery cell according to a first example; Fig. 4 Characteristic curve to explain a second test cycle of the battery cell according to the first example; Fig. 5 Characteristic curve to explain a first test cycle of a battery cell according to a second example; Fig. 6 Characteristic curve to explain a second test cycle of the battery cell according to the second example; Fig. 7. Characteristic curve to illustrate a first test cycle of a battery cell according to a third example; and Fig. 8 Characteristic curve to explain a second test cycle of the battery cell according to the third example. Fig. 9 characteristic curves to illustrate the stability of the battery cell during multiple test cycles.

[0081] The Fig.Figure 1 shows a simplified schematic representation of a first exemplary structure of a battery cell, which is generally designated by the reference numeral 10.

[0082] The battery cell 10 has a stacked arrangement of alternatingly arranged positive electrodes 12 and negative electrodes 14 (in Fig. (1 only one is shown in each case), wherein a separator 16 is arranged between two adjacent electrodes 12, 14.

[0083] In the example, the positive electrode 12 comprises a carrier material 18, on which the first electrode material 20, comprising cathode active material, is arranged on both sides.

[0084] In the example, the negative electrode 14 comprises a substrate 22 on which a layer of a second electrode material 24, in particular a metal layer, is arranged on both sides.

[0085] The Fig.Figure 2 shows a simplified schematic representation of another embodiment of a battery cell 10', which is designed as a wound cell. Specifically, the battery cell 10' has several positive and negative electrodes 12', 14', which are stacked alternately and between which a separator 16' is arranged. The electrodes 12', 14' and the separators 16' are then wound to form the wound cell.

[0086] As from Fig. As can be seen in Figure 2, the battery cell 10' also has a positive electrode terminal 26' and a negative electrode terminal 28'.

[0087] Several specific examples are described below. Example 1: First metal: lithium Cathode active material: Lithium iron phosphate Positive electrode: Pellet Second metal: zinc Negative electrode: Zinc foil (70 µm thickness) Starting electrolyte: LiCl (2.0 mol / l) and ZnCl2 (2.5 mol / l) ionized water Battery cell structure: button cell Positive electrode:

[0088] To produce the positive electrode, used raw cathode material was obtained from used lithium-ion batteries with lithium iron phosphate as the cathode active material.

[0089] The raw cathode material was ground to obtain a raw cathode material powder and further processed without removing the binder and conductive components contained in the raw cathode material.

[0090] In this specific example, the raw cathode material powder was mixed with carbon black as a conductive component and a nano-dispersion of polyurethane (PU) in water as a binder in such a way that a mass ratio of raw cathode material powder / carbon black / PU of 20:1:1 was obtained.

[0091] The mixture was thoroughly blended to obtain a paste and pelletized onto a graphite plate at 80 °C.

[0092] In this specific example, the pellet obtained had a thickness of 0.8 mm and a diameter of 12.2 mm. Negative electrode:

[0093] A zinc foil with a thickness of 50 µm was used as the negative electrode. Starting electrolyte:

[0094] A solution of LiCl (2.0 mol / l) and ZnCl2 (2.5 mol / l) in deionized water was used as the starting electrolyte. Battery cell:

[0095] Using the pellet as the cathode, the zinc foil as the anode, and the starting electrolyte, a battery cell in the form of a button cell was constructed. No separator was used. The distance between the cathode and anode was set to 1 mm. Tests:

[0096] Various tests were carried out on the manufactured battery cell to characterize its properties.

[0097] In a first test cycle (see Fig. 3) The battery cell was initially charged at 5 mA / cm² 2 charged to 1.5 V and then at 2 mA / cm 2 discharged to 0.9 V.

[0098] As from Fig. 3. These were evident during the first charge of Li + -ions corresponding to a capacity of 3.2 mAh / cm² 2extracted from the cathode active material. During unloading, Li + -ions corresponding to a capacity of 5.9 mAh / cm² 2 embedded in the cathode active material. This suggests that Li + -ions corresponding to a capacity of 2.7 mAh / cm² 2 from the electrolyte were incorporated into the cathode active material, resulting in a capacity increase of 84%.

[0099] In a second test cycle, charging and discharging capacities of 4.8 mAh / cm² were then achieved. 2 achieved, which shows that the capacity obtained from the starting electrolyte is available for reversible charge storage in the battery cell. Example 2: First metal: lithium Cathode active material: Lithium iron phosphate Positive electrode type: Squeegee coating on substrate Second metal: zinc Negative electrode: Zinc foil (70 µm thickness) Starting electrolyte: LiCl (2.0 mol / l) and ZnCl2 (2.5 mol / l) in deionized water Battery cell structure: Pouch cell Positive electrode:

[0100] To produce the positive electrode, used raw cathode material was obtained from used lithium-ion batteries with lithium iron phosphate as the cathode active material.

[0101] The raw cathode material was ground and sieved to obtain a raw cathode material powder with a particle size of 125-250 µm.

[0102] The resulting raw cathode material powder was further processed without removing the binder and conductive components contained in the raw cathode material.

[0103] In the specific example, a suspension comprising the raw cathode material powder, carbon black as a conductive component and a binder was produced, with a mass ratio of cathode material powder / carbon black / binder of 18:1:1.

[0104] A mixture of a nanodispersion of polyurethane (PU) in water and sodium carboxymethylcellulose (CMC) was used as a binder. The PU nanodispersion and CMC were thoroughly mixed in a mass ratio of 4:1 to prepare the binder mixture.

[0105] Additional deionized water was added to obtain a suspension with the desired viscosity.

[0106] The suspension was applied to a foil made of stainless steel 316 (SS, 20 µm thickness) with a wet thickness of 0.7 mm using a squeegee coating.

[0107] The steel substrate coated with the suspension was dried for 3 hours in ambient air and then for 3 hours in an oven at 80 °C.

[0108] The final thickness of the coated steel substrate was 0.5 mm with a mass loading of 46 mg / cm². 2 .

[0109] An electrode measuring 2× 3 cm was then cut from the coated steel substrate to assemble a pouch cell. Negative electrode:

[0110] A zinc foil with a thickness of 50 µm was used as the negative electrode. Starting electrolyte:

[0111] A solution of Li2SO4 (1.5 M) and ZnSO4 (1.0 M) in deionized water was used as the starting electrolyte. Battery cell:

[0112] A pouch cell was fabricated from the coated steel substrate as the cathode, the zinc foil as the anode, and the starting electrolyte. A glass fiber filter (0.26 mm thick, 52 g / m²) was used. 2 A density-resistant material was used as a separator between the cathode and anode. A transparent, heat-sealable polypropylene film (0.1 mm thick) was used as the container for the pouch cell. Tests performed:

[0113] Various tests were carried out on the manufactured battery cell to characterize its properties.

[0114] In an initial test cycle, the battery cell was first operated at 0.5 mA / cm². 2 charged to 1.5 V and at 0.5 mA / cm 2 discharged to 0.9 V.

[0115] As from Fig.5. These were evident during the first charge of Li + Ions corresponding to a capacity of 57 mAh / g of raw cathode material were extracted from the cathode active material. During discharge, Li + -Ions corresponding to a capacity of 90 mAh / g of raw cathode material are incorporated into the cathode active material. This indicates that Li + -Ions corresponding to a capacity of 33 mAh / g from the starting electrolyte were incorporated into the cathode active material, representing a capacity gain of 58%.

[0116] In the second test cycle, charging and discharging capacities of 81 mAh / g and 80 mAh / g were achieved, demonstrating that the capacity obtained from the initial electrolyte was available for reversible charge storage in the battery cell. Example 3: First metal: lithium Cathode active material: Lithium iron phosphate Positive electrode type: Pellet Second metal: zinc Negative electrode: Zn-deposited Cu foil (100 µm thickness) Starting electrolyte: LiCl (2.0 mol / l) and ZnCl2 (2.5 mol / l) in deionized water Battery cell structure: button cell Positive electrode:

[0117] In this example, a fresh (unused) lithium iron phosphate electrode (93 wt% lithium iron phosphate with a capacity of 150 mAh / g) was charged to obtain Li + -Ions with a capacity of 120 mAh / g to be stored accordingly.

[0118] This on Li + The lithium iron phosphate electrode, depleted of ions, was thoroughly washed with deionized water and dried.

[0119] The black mass was left exposed to ambient air for 20 days before being used as spent LFP for the following experiments without removing the original binder and conductive additives (hereinafter referred to as R-LFP).

[0120] In this specific example, the raw cathode material powder was mixed with carbon black as a conductive component and a nano-dispersion of polyurethane (PU) in water as a binder in such a way that a mass ratio of raw cathode material powder / carbon black / PU of 20:1:1 was obtained.

[0121] The mixture was thoroughly blended to obtain a paste and pelletized on a graphite plate at 80 °C.

[0122] The resulting pellet had a thickness of 0.9 mm and a diameter of 12.2 mm. Negative electrode:

[0123] To produce the negative electrode, a Zn layer was deposited onto a Cu foil (100 µm) by electroplating at 5 mA / cm². 2 Produced for 2 hours, followed by washing with deionized water and drying. Starting electrolyte:

[0124] A solution of LiCl (2.0 mol / l) and ZnCl2 (2.5 mol / l) in deionized water was used as the starting electrolyte. Battery cell:

[0125] Using the pellet as the cathode, the zinc foil as the anode, and the starting electrolyte, a battery cell in the form of a button cell was constructed. No separator was used. The distance between the cathode and anode was set to 1 mm. Tests:

[0126] Various tests were carried out on the manufactured battery cell to characterize its properties.

[0127] In a first test cycle (see Fig. 7) The battery cell was initially charged at 2 mA / cm² 2 charged to 1.5 V and then at 2 mA / cm 2 discharged to 0.9 V.

[0128] As from Fig. As can be seen in the 7, during the first charge Li +Lithium ions corresponding to a capacity of 27 mAh / g of raw cathode material were extracted from the cathode active material. This corresponds to the lithium remaining in the cathode active material after the initial extraction of 120 mAh / g. + -ions. During discharge, Li were then produced. + -ions corresponding to a capacity of 125 mAh / g of crude cathode material are incorporated into the cathode active material. This suggests that Li + Ions corresponding to a capacity of 98 mAh / g of crude cathode material were deposited from the starting electrolyte into the cathode active material.

[0129] The Fig. Figure 9 shows the result of a long-term test in which several charge and discharge cycles were performed. The measured values ​​represented by triangle symbols represent the discharge capacity, and the measured values ​​represented by square symbols represent the Coulomb efficiency. As shown from Fig.As can be seen in Figure 9, even after 15 test cycles no significant change in discharge capacity and Coulomb efficiency is apparent.

Claims

[1] Method for producing a rechargeable alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery using spent cathode active material from at least one spent alkaline ion battery or alkaline earth ion battery, comprising: - Providing a positive electrode (12), in particular a cathode, comprising a first electrode material (20), wherein the first electrode material (20) contains or consists of used cathode active material from at least one used alkaline-ion battery or used alkaline earth-ion battery, wherein the used cathode active material is configured to reversibly incorporate ions of a first metal, wherein the first metal is an alkali metal, in particular lithium, or an alkaline earth metal; - Providing a negative electrode (14), in particular anode, comprising a second electrode material (24), wherein the second electrode material (24) contains or consists of a second metal, wherein the second metal is selected from the group consisting of magnesium, aluminium and transition metal, preferably zinc; - Providing a starting electrolyte, comprising or at least a salt of the first metal; or at least one salt of the second metal; o at least one solvent, in particular water, organic solvents or mixtures thereof; - Manufacturing a battery cell (10) from the positive electrode (12), the negative electrode (14) and the initial electrolyte, wherein the first electrode material (20) and the second electrode material (24) are in contact with the initial electrolyte. [2] The method of claim 1, further comprising, after the production of the battery cell (10): carrying out a re-metallization step, in particular a re-lithiation step, to increase the number of ions of the first metal incorporated in the used cathode active material, in particular wherein the re-metallization step comprises at least partially discharging the battery cell, preferably at a C-rate between 0.2C and 2C, such that ions of the first metal from the starting electrolyte are incorporated into the cathode active material. [3] Method according to the previous claim, wherein no active re-metallization of the used cathode active material takes place prior to the re-metallization step. [4] Method according to any of the preceding claims, wherein the provision of the positive electrode (12) comprises the provision of crude cathode material from at least one used alkaline-ion battery or alkaline earth-ion battery and the further processing of the crude cathode material to the first electrode material (20), wherein the crude cathode material contains or consists of the used cathode active material. [5] Method according to the previous claim, wherein the crude cathode material comprises, in addition to the used cathode active material, at least one binder and optionally a carbon material, wherein the at least one binder and the optional carbon material are not removed or are removed to no more than 10 wt.% when further processing the crude cathode material to the first electrode material, based on an initial content of the binder or carbon material in the crude cathode material. [6] Method according to claim 4 or 5, wherein the further processing of the crude cathode material to the first electrode material (20) the addition of at least one binder, in particular selected from the group consisting of PVDF, PTFE, PU, ​​CMC, SBR, PAA PVA, and combinations thereof, and / or the addition of at least one conductive component, especially carbon component, to the raw cathode material. [7] Method according to any of the preceding claims, wherein providing the positive electrode comprises providing an electrically conductive support material (18) and applying a layer of the first electrode material (20) to the support material (18). [8] Method according to the preceding claim, wherein the mass density of the used cathode active material on the support material (18) is more than 20 mg / cm² 2 , preferably between 50 mg / cm² 2and 150 mg / cm² 2 , preferably between 75 mg / cm² 2 and 125 mg / cm² 2 amounts. [9] Method according to claim 7 or 8, wherein the application of the layer of the first electrode material (20) onto the support material (18) comprises the preparation of a suspension comprising the used cathode active material and the deposition of the suspension onto the support material (18). [10] Method according to the preceding claim, wherein the suspension contains: - the used cathode active material; - if necessary, at least one binder, in particular selected from the group consisting of PVDF, PTFE, PU, ​​CMC, SBR, PAA, PVA and combinations thereof; - possibly at least one conductive component, in particular a carbon component; - at least one solvent, in particular selected from the group consisting of water, alcohols, acetone, NMP (N-methyl-2-pyrrolidone), DMSO, DMF and combinations thereof. [11] Method according to any one of claims 1 to 8, wherein the provision of the positive electrode (12) comprises the provision of a powder from the used cathode active material, optionally the at least one binder and optionally the at least one conductive component, and the pressing of this powder into a press body. [12] Method according to one of the preceding claims, wherein the negative electrode (14) comprises a foil, in particular a self-supporting foil, made of the second electrode material (24), in particular a metal foil, or wherein the negative electrode comprises a substrate (22) made of a substrate material onto which a layer of the second electrode material (24) is applied, in particular wherein the substrate material is selected from the group consisting of Cu, Ti, Ni, Sn, Al, stainless steel, graphite and combinations thereof. [13] Method according to any of the preceding claims, wherein a concentration of the at least one salt of the first metal in the starting electrolyte is determined according to the following formula: c=mCAMCCAM(1−XCAM)VElnMe1+F+c0nMe1+ where: - m CAM the total mass of the cathode active material used in the battery cell; - C CAM the gravimetric capacity of the cathode active material is; - X CAM the content of the ions of the first metal incorporated in the used cathode active material relative to an original content of the ions of the first metal in the unused cathode active material; - V El the volume of the electrolyte; - n Me1+ the number of ions of the first metal in the salt; - F is the Faraday constant; - c0 is a concentration between 0.5 mol / and 1 mol / l. [14] Method according to any of the preceding claims, wherein the cathode active material used is a mixed oxide of composition A n M' a M" b M"' c M'"' d O e , is, where: - A is a metal selected from the group formed by the metals of groups 1, 2 and 13 of the periodic table of elements, where A is different from M', M", M''' and M""; - M' is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M' is different from A, M", M'" and M""; - M" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M" is different from A, M', M'" and M""; - M'" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M'" is different from A, M', M" and M""; - M"" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M'"' is different from A, M', M" and M'"; - a + b + c + d = 1, a ≥ 0, b ≥ 0, c ≥ 0, d ≥ 0, e > 0; - n > 0 and preferably n < 1. [15] Method according to any of the preceding claims, wherein the cathode active material used is a Prussian blue analogue of the composition A n M' a M" e [Fe(CN)6]·mH2O is, whereby: - A is a metal selected from the group formed by the metals of groups 1, 2 and 13 of the periodic table of elements, where A is different from M' and M"; - M' is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M' is different from A and M"; - M" is an element selected from the group formed by the elements of groups 2, 3, 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the periodic table of elements, where M is different from A and M'; - a + b = 1, a ≥ 0, b ≥ 0; - m ≥ 0 - n > 0 and preferably n < 1. [16] A method according to any one of the preceding claims, wherein the first metal is lithium, wherein the The cathode active material selected is from the group consisting of Lithium iron phosphate, Lithium manganese iron phosphate, lithium-nickel-manganese-cobalt oxide, Lithium cobalt(III) oxide, Lithium nickel cobalt aluminum oxide, Berlin blue analogues, in particular of the composition LiM[Fe(CN)6] with M = Fe, Co, Ni, Cu, or Mn, and Combinations thereof. [17] Method according to any of the preceding claims, wherein the first metal is lithium, wherein the cathode active material is lithium iron phosphate from used lithium-ion batteries, and wherein the second metal is zinc. [18] Alkali metal-metal hybrid battery or alkaline earth metal-metal hybrid battery manufactured according to any of the preceding claims.

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