DE102011109134A1 - Electrochemical cell for use in lithium ion batteries for power supply for e.g. mobile information devices, has electrochemical active material treated by predetermined procedure, which does not contain charging or discharging steps - Google Patents

Abstract

The cell has a negative electrode and/or a positive electrode comprising an electrochemical active material, which forms a solid electrolyte interface, a solid electrolyte interface layer on parts of a surface of the negative electrode and/or the positive electrode. The electrochemical active material is partially treated by a predetermined procedure, which does not contain charging or discharging steps and contains solid electrolyte interface layer regeneration and/or formation steps. The electrochemical active material is treated with electrolyte and/or additive. An independent claim is also included for a method for regenerating electrochemical active material.

Description

The present invention relates to an electrochemical cell, wherein the electrochemical cell has at least one electrode which has electrochemical active material which has been treated, in particular regenerated, by predetermined external measures, in particular by renewal and / or reformation of the SEI layer. The cell can preferably be used in batteries for the drive of vehicles with electric motor, preferably with hybrid drive or in "plug in" operation.

Electrochemical cells, especially lithium secondary batteries, find because of their high energy density and high capacity as energy storage in mobile information devices such. As mobile phones, in tools or in electrically powered cars and in automobiles with hybrid drive application. Despite these very different fields of application of electrochemical cells, all cells used, but especially those for driving automobiles, have to fulfill high requirements: the highest possible electrical capacity and energy density, which remains stable over a large number of charging and discharging cycles, with the lowest possible weight.

The longevity of electrochemical cells is often dependent on the aging of the electrodes. During the aging process, the electrochemical cells lose in particular in capacity and performance. This process takes place to a greater or lesser extent in most common electrochemical cells, depending on the circumstances of use (temperature, storage conditions, state of charge, etc.), but also the quality and processing of the materials during the electrochemical cell manufacturing process.

Numerous measures are described in the literature to increase the aging stability of electrochemical cells. However, the aging process can often only be slowed down but not completely suppressed because, for example, chemical reactions take place inside the cell during the operation of a cell, some of which are irreversible.

An example of such a chemical reaction is the formation of the so-called SEI layer. The solid electrolyte interface (SEI) layer is formed at the interface between the active material of the cathode and / or the anode and the nonaqueous electrolyte during the first charge and discharge cycles, and consists essentially of reaction products of electrolyte and active material , Such reaction products may be, for example, Li ₂ O, LiF, polymeric compounds or (semi) carbonates such as Li ₂ CO ₃ . The initial formation of the SEI layer results in an initial irreversible capacity loss of the electrochemical cell. Some of the aforementioned reaction products, such as the (semi) carbonates, are metastable compounds which, under certain conditions (eg, heat), can be degraded to more stable products, such as LiF. This can lead to the formation of cracks within the SEI layer, as a result of which electrolyte can increasingly penetrate into the active material again and decompose it further, which can lead to a further irreversible loss of capacity and thus to a further progressive aging of the cell; the SEI layer is growing.

The further the capacity loss, particularly due to SEI growth, and thus the aging of the electrochemical cell progresses, the lower the cell performance will be until the power is so low that the electrochemical cell needs to be replaced ,

In order to delay this time as long as possible, there are in the literature methods for substantially non-destructive rejuvenation of electrochemical cells, for example in the patent documents DE 10 2009 054 016 or US 201010068605 , This goal is achieved for example by electrolyte exchange.

However, intact and "spent" cells may still have intact portions of electrochemical active material coated, for example, by a relatively thick SEI layer. Since the production of the electrochemical active material is often associated with a considerable cost and in particular energy consumption, and also the natural resources are limited to raw materials such as lithium or cobalt, it is also due to the ever increasing demand for lithium-ion batteries, more important recovering intact electrochemical active material from "old" cells for reuse in new cells.

The invention has for its object to provide an electrochemical cell, which can be produced inexpensively and with low energy and material costs than corresponding electrochemical cells from the prior art.

This is achieved according to the invention by the teaching of the independent claims. Preferred developments of the invention are the subject of the dependent claims.

The underlying object is achieved by having an electrochemical cell at least one negative electrode and at least one positive electrode, wherein the at least one negative electrode and / or the at least one positive electrode comprises electrochemical active material which is capable of a "solid electrolyte interface", ie an SEI layer, on at least parts of the surface the at least one negative electrode and / or the at least one positive electrode, wherein the electrochemical active material has been treated at least in part by at least one predetermined measure which is not charging or discharging an electrochemical cell, and the renewal and / or reformation of the SEI Layer includes.

One of the advantages of the present invention is that valuable resources, such as energy and raw materials, needed to re-synthesize electrochemical active material are saved, and costs for producing electrochemical cells are reduced.

In one embodiment of an electrochemical cell according to the invention, the at least one predetermined measure is selected from:

• At least partial rejuvenation of an SEI layer by mechanical force and / or
• At least partially removing the SEI layer using at least one solvent and / or
• Treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive.

In one embodiment of an electrochemical cell according to the invention, the at least one additive is selected from phenylene carbonate, fluorine-containing or non-fluorine-containing lithium organoborates, in particular lithium difluoro (oxalato) borate (LiDFOB) or lithium bis (oxalato) borate (LiBOB) and fluorine-containing or non-fluorine-containing lithium organophosphates , in particular lithium tetrafluoro (oxalato) phosphate (LiTFOP) or lithium tris (oxalato) phosphate (LiTOP).

In one embodiment of an electrochemical cell according to the invention, the mechanical force has at least one abrasive process, in particular scraping and / or removal and / or abrasion and / or abrasion.

In one embodiment of an electrochemical cell according to the invention, the at least one solvent is selected from polar organic solvents, non-polar organic solvents, or ionic liquids.

According to the invention, the electrochemical cell is used for supplying energy to mobile information devices, tools, electrically powered automobiles, hybrid-powered automobiles and stationary energy storage devices.

For the purposes of the present invention, the electrochemical active material is removed irreversibly from an electrochemical cell which has already been subjected to at least one charging and discharging cycle, wherein the at least one charging and discharging cycle was preferably not carried out for the purpose of conditioning the electrochemical cell.

The present invention further provides electrochemical active material which has already been subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle is preferably not performed for the purpose of conditioning the electrochemical cell obtainable by employing at least one predetermined measure with respect to the electrochemical active material wherein the at least one predetermined measure is not charging or discharging an electrochemical cell and includes renewing and / or rebuilding the SEI layer.

• • zumindest teilweises Verjüngen einer SEI-Schicht durch mechanische Krafteinwirkung und/oder
• • zumindest teilweises Entfernen der SEI-Schicht unter Verwendung von zumindest einem Lösemittel und/oder
• • Behandlung des elektrochemischen Aktivmaterials mit mindestens einer SEI-Schicht-bildenden und/oder SEI-Schicht-unterstützenden Substanz, insbesondere mit mindestens einem Elektrolyt und/oder mindestens einem Additiv.

In one embodiment of the electrochemical active material according to the invention, the at least one predetermined measure is selected from:

• At least partial rejuvenation of an SEI layer by mechanical force and / or
• At least partially removing the SEI layer using at least one solvent and / or
• Treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive.

The electrochemical active material according to the invention has preferably been removed irreversibly from an electrochemical cell which has been subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle was preferably not carried out for the purpose of conditioning the electrochemical cell.

The electrochemical active material according to the invention can preferably be used in electrodes of electrochemical cells.

• • zumindest teilweises Verjüngen einer SEI-Schicht durch mechanische Krafteinwirkung und/oder
• • zumindest teilweises Entfernen der SEI-Schicht unter Verwendung von zumindest einem Lösemittel und/oder
• • Behandlung des elektrochemischen Aktivmaterials mit mindestens einer SEI-Schicht-bildenden und/oder SEI-Schicht-unterstützenden Substanz, insbesondere mit mindestens einem Elektrolyt und/oder mindestens einem Additiv,

wobei das elektrochemische Aktivmaterial irreversibel einer elektrochemischen Zelle entnommen wurde, die zumindest einem Lade- und Entladezyklus unterworfen wurde, wobei der mindestens eine Lade- und Entladezyklus vorzugsweise nicht zum Zwecke der Konditionierung der elektrochemischen Zelle durchgeführt wurde.The invention further provides a method for the treatment, in particular for the regeneration of electrochemical active material by at least a predetermined measure, preferably selected from:

• At least partial rejuvenation of an SEI layer by mechanical force and / or
• At least partially removing the SEI layer using at least one solvent and / or
• Treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive,

wherein the electrochemical active material has been irreversibly removed from an electrochemical cell subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle has preferably not been carried out for the purpose of conditioning the electrochemical cell.

An "electrochemical cell" in the sense of the present invention means any type of device for the electrical storage of energy. The term thus includes in particular electrochemical cells of the primary or secondary type, but also other forms of energy storage, such as capacitors. Preferably, an electrochemical cell is to be understood as a lithium-ion battery / cell.

In a preferred embodiment, the electrochemical cell has at least one positive electrode, at least one negative electrode, and at least one separator separating the positive from the negative electrode, wherein the electrodes and separator are at least partially surrounded by at least one sheath.

"Brand new" in the sense of the present invention is to be understood that the electrochemical active material used is an electrochemical active material which has not previously been used in an electrochemical cell and has not been subjected to a separation and grinding and / or classification process, that is not yet been applied once to a metallic substrate such as preferably aluminum or copper; or which does not originate from a battery which has already been used at least once as a power source, ie has been charged and / or discharged at least once in the case of a secondary battery. The term "virgin" below means that this material is used for the first time as an electrochemical active material in an electrode material for an electrode. Furthermore, "brand new" also means that in one embodiment, the surface of the electrochemical active material has never been coated, even partially, with an SEI layer formed during the first loading and / or unloading operations.

According to the invention, the at least one positive and / or the at least one negative electrode electrochemical active material which is capable of forming on the surface of the electrochemical active material exposed to the electrolyte, a "solid electolyte interface", also called SEI layer.

The electrochemical active material of the at least one positive and / or at least one negative electrode in the sense of the present invention contains at least partially treated, in particular regenerated, electrochemically active material.

In one embodiment, up to 10%, preferably up to 20%, preferably up to 30%, preferably to 40%, preferably to 50%, preferably to 60%, preferably to 70%, preferably to 80%, preferably to 90% , preferably up to 100% of the active material of the at least one negative electrode treated electrochemical active material.

In one embodiment, up to 10%, preferably up to 20%, preferably up to 30%, preferably to 40%, preferably to 50%, preferably to 60%, preferably to 70%, preferably to 80%, preferably to 90% , preferably up to 100% of the active material of the at least one positive electrode treated electrochemical active material.

In a further embodiment, the treated electrochemical active material of the at least one positive and / or at least one negative electrode is added as a conductivity additive to the electrode material. The treated electrochemical active material of the at least one positive and / or at least one negative electrode can be used as the sole conductivity additive or with at least one further conductivity additive. Preferably, a conductivity additive mixture of at least two conductivity additives up to 2%, preferably up to 5%, preferably up to 7%, preferably up to 10%, more preferably between 2.5% to 4.8% treated electrochemical active material as a conductivity additive. An SEI layer according to the present invention is preferably formed during the first charge and / or discharge cycles at least partially on the surface of the electrochemical active material of the at least one positive and / or negative electrode.

The formation of the SEI layer can by reaction of a lithium ion-containing electrolyte with the exposed to the electrolyte surface of the active material. But it is also possible that the formation of the SEI layer by the reaction of an SEI layer-forming or SEI layer affecting additive such as LiBOB occurs.

Preferably, up to 40%, preferably up to 70%, further preferably up to 100% of the surface area of the electrochemical active material, an SEI layer is formed.

Preferably, the SEI layer has electrically insulating and lithium ion conducting properties.

Preferably, the SEI layer at least partially comprises compounds of the following group: inorganic lithium salts, in particular LiF, LiOH, Li ₂ O, (semi) carbonates, in particular Li ₂ CO ₃ , ROCO ₂ Li (where R = alkyl, olefin, Alkenyl or aromatic substituents) and (CH ₂ OCO ₂ Li) ₂ , polymeric compounds, especially polyolefins, or mixtures thereof.

Preferably, a newly formed or renewed SEI layer has an average thickness of greater than 0 nm up to 20 nm, preferably up to 30 nm, preferably up to 40 nm, preferably up to 50 nm.

In one embodiment, a newly formed or renewed SEI layer on the electrochemical active material of a negative electrode has an average greater thickness than a newly formed or renewed SEI layer on the electrochemical active material of a positive electrode.

In another embodiment, a newly formed or renewed SEI layer on the electrochemical active material of a negative electrode has an average smaller thickness than a newly formed or renewed SEI layer on the electrochemical active material of a positive electrode.

In another embodiment, a newly formed or renewed SEI layer on the electrochemical active material of a negative electrode has an average same thickness as a newly formed or renewed SEI layer on the electrochemical active material of a positive electrode.

For the purposes of the present invention, "newly formed" or "new formation" means that a new SEI layer is formed on the surface of electrochemical active material. Preferably, less than 10%, preferably less than 5%, preferably less than 2%, further preferably 0% of the surface of the electrochemical active material is coated with an already existing SEI layer before the reshaping of the SEI layer. After the reshaping of the SEI layer, preferably up to 50%, preferably up to 70%, further preferably up to 100%, of the surface of the electrochemical active material has an SEI layer.

"Renewed" or "renewal" in the sense of the present invention means that an already formed on the surface of the electrochemical active material SEI layer is treated and preferably changed in their chemical or physical properties. The treatment of the SEI layer may preferably be carried out such that cracks or pores in the SEI layer are closed or the thickness of the SEI layer is reduced.

The at least partial renewal or reformation of the SEI layer has the advantage that electrochemical active material is treated in a simple manner and in particular regenerated, so that it can be reused in an electrode of an electrochemical cell. It has surprisingly been found that electrodes which at least partially comprise electrochemical active material which has already been used in electrodes of electrochemical cells have a conductivity which is up to 10%, preferably up to 15%, higher than electrodes which are used exclusively for the first time in An active material used for an electrochemical cell, ie "brand new" electrochemical active material.

In one embodiment, the brand-new active material has hitherto only been subjected to at least one charge and / or discharge cycle for the purpose of conditioning.

Conditioning is to be understood as meaning that measures are carried out, in particular loading and unloading operations, in particular also at temperatures which are higher or lower than 25 ° C. Furthermore, conditioning may also include storage of charged cells at higher temperatures. The purpose of the conditioning of an electrochemical cell is to form a stable SEI layer on the surface of the electrochemical active material for the first time.

It is particularly preferred according to the invention for at least one positive and / or at least one negative electrode to be removed from an already operated electrochemical cell, in particular if the at least one positive and / or the at least one negative electrode has a significantly reduced capacitance.

The removal of the damaged or no longer fully efficient electrode, and in particular the removal of the electrochemical active material to be treated with at least one predetermined measure from the electrochemical cell is preferably irreversible. The electrochemical cell is at least partially destroyed, as now at least one electrode has been removed, and thus is missing. Destroying does not mean that the electrochemical cell in its entirety is destroyed. It is quite preferable that a damaged electrode is removed, and replaced by another functional electrode, which may have an electrochemical active material according to the invention, and is thus reusable. The term "irreversible" here means that the application of the at least one predetermined measure can only be carried out if the electrode and in particular the electrochemical active material are removed from the electrochemical cell.

In one embodiment, the remote electrode is first examined for damage, for example with the aid of microscope devices or radiographic methods.

This has the advantage that first the type of damage to the electrode can be determined in order to determine the subsequent measures for the treatment and in particular for the regeneration of the electrode, in particular of the electrochemical active material of the present damage accordingly.

The term "predetermined measure" is to be understood according to the invention that at least one measure is taken, which was determined preferably taking into account the present defect of the electrode. The aim of the at least one predetermined measure is to treat electrochemical active material of an electrode in such a way that the electrochemical active material can again be used in an electrode of an electrochemical cell, ie it is preferably regenerated. This is achieved according to the invention by an at least partial reformation and / or renewal of the SEI layer located on the surface of the electrochemical active material to be treated by at least one predetermined measure.

In one embodiment, the electrode has a mixture which, in addition to the electrochemical active material, also contains at least one further compound and / or at least one further substance, in particular at least one binder and / or at least one conductivity additive and / or electrolyte. It is advantageous, prior to application of the at least one predetermined measure, a possibly in addition to the electrochemical active material containing at least one compound and / or the at least one substance, in particular the at least one binder contained and / or the at least one additive, in particular conductivity additive and / or electrolyte to be separated from the electrochemical active material.

The advantage is that the at least one predetermined measure can essentially act completely on the electrochemical active material. The effectiveness of the treatment of the electrochemical active material by the at least one predetermined measure is thereby increased.

The methods for separating the electrochemical active material from the optional additional at least one compound and / or at least one substance should be selected depending on the chemical and / or physical properties of the compound to be separated from the electrochemical active material and / or the substance to be separated.

In principle, it is possible to use essentially all separation processes conceivable for the separation of mixtures of substances and / or compounds.

Preferably, the at least one compound to be separated from the electrochemical active material and / or the substance to be separated is not damaged or destroyed in the separation or by the separation process, so that the at least one compound and / or the at least one substance also in an electrochemical cell, preferably after Application of cleaning and / or (up) concentration methods, can be used again.

This has the advantage that such valuable materials for the assembly and / or operation of electrochemical cells do not have to be newly produced or purchased. This lowers production costs and saves valuable resources.

Particularly preferably, the separation of the at least one compound and / or the at least one substance from the electrochemical active material is carried out using solvents. In particular, organic and / or polymeric compounds and / or substances can be separated by the use of suitable solvents due to the ability to substantially completely dissolve in the appropriate solvent substantially insoluble constituents, such as the electrochemical active material, in particular by centrifugation and / or filtering methods.

Suitable solvents, in particular for separating off binders, in particular polyvinylidene fluoride (PVdF), are dimethylformamide (DMF), dimethylacetamide (DMAC) or, more preferably, N-methylpyrrolidone (NMP) or mixtures thereof.

However, it is also possible to use further solvents, preferably organic solvents, in particular tetrahydrofuran (THF), ethylene carbonate (EC) or γ-butyrolactone (GBL) or mixtures thereof.

In a preferred embodiment, at least one predetermined measure comprises a tapering or at least partial, preferably complete removal of the SEI layer of the electrochemical active material, in particular by mechanical action of force and / or at least partial removal and / or dissolution of the SEI layer using at least one solvent and / or the treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular at least one electrolyte or at least one additive.

Through the application of mechanical force, in particular having at least one abrasive process, in particular shaving and / or removal and / or abrasion and / or sanding, at least partially on the surface of the SEI layer which is exposed to the environment, the thickness of the SEI Layer at least partially changed, in particular diluted or the SEI layer can be at least partially completely removed. The effectiveness of this measure can be increased if any other compounds or substances such as conductivity additives or binders are separated from the electrochemical active material before application of the mechanical force.

The at least one abrasive process can be applied at least partially to the SEI layer of the electrochemical active material, in particular by means of corresponding devices which preferably have a rough surface. In one embodiment, a washing-drum type device is used, which rotates about an axis, which is preferably arranged orthogonal to the direction of gravity, whereby the electrochemical active material contained in the washing drum-like device is set in motion. At this time, the electrochemical active material grinds along the surface of the washing drum-like device, whereby the SEI layer contained on the surface of the electrochemical active material is at least partially subjected to abrasive processes. In a further embodiment, the electrochemical active material is arranged on a belt-shaped device which performs movements, in particular shaking movements, whereby the SEI layer contained on the surface of the electrochemical active material is at least partially subjected to abrasive processes. In a further embodiment, the electrochemical active material is arranged between two devices, wherein at least one of the devices has a rough surface facing the electrochemical active material. The SEI layer on the surface of the electrochemical active material is at least partially in contact with the devices. The devices perform abrasive operations by movements, in particular by opposite movements, preferably rubbing movements. It is conceivable to exert pressure on the electrochemical active material located between the devices in order to enhance the effect of the abrasive processes.

In one embodiment, the at least one predetermined measure is followed by a purification of the treated electrochemical active material, and to remove any residues of old electrolyte or old SEI layer.

Suitable solvents for at least partial removal and / or dissolution of the SEI layer are polar organic solvents, nonpolar organic solvents, or ionic liquids. In particular for the at least partial removal and / or dissolution of constituents of the SEI layer, which organic compounds, in particular organic polymeric compounds, have corresponding organic solvents. For the at least partial removal and / or dissolution of constituents of the SEI layer which have salts, in particular lithium salts, in particular inorganic lithium salts, ionic liquids are suitable. In one embodiment, the SEI layer is first treated with polar and / or non-polar organic solvents, and then with at least one ionic liquid.

In one embodiment, the SEI layer is at least partially fluorinated by using at least one SEI layer-forming and / or SEI layer-supporting substance, in particular at least one electrolyte and / or at least one additive which is preferably selected from phenylene carbonate or non-fluorine-containing lithium organoborates, in particular lithium difluoro (oxalato) borate (LiDFOB) or lithium bis (oxalato) borate (LiBOB) and fluorine-containing or non-fluorine-containing lithium organophosphates, in particular lithium tetrafluoro (oxalato) phosphate (LiTFOP) or lithium tris (oxalato) phosphate (LiTOP). The electrolyte used and / or Additives are capable of affecting the formation of the SEI layer on the electrochemical active material, in particular, forming the SEI layer on the electrochemical active material with the electrochemical active material.

In a preferred embodiment, highly pure electrolyte is applied to the electrochemical active material or to parts of the electrochemical active material on which at least partially the SEI layer is to be newly formed. The order of the high-purity electrolyte is preferably carried out by pipetting, brushing, dripping or spraying or other suitable measures for the electrolyte. Preferably, an excess of high purity electrolyte, in particular up to 3%, preferably up to 4%, preferably up to 5%, preferably up to 6%, preferably up to 7%, excess of high purity Electrolyte used. The term "excess" in the present case refers to the (theoretically) calculated amount of electrolyte which is required by the manufacturer of the electrolyte to fill a standard lithium-ion cell. If one uses just an excess of electrolyte, that is more, preferably up to 7% more electrolyte than theoretically required, this has the advantage that the cell has a longer life.

The electrolyte may additionally comprise an additive which is preferably selected from fluorine-containing or non-fluorine-containing lithium organoborates, in particular lithium difluoro (oxalato) borate (LiDFOB) or lithium bis (oxalato) borate (LiBOB) and fluorine-containing or non-fluorine-containing lithium organophosphates, in particular lithium tetrafluoro (oxalato) phosphate (LiTFOP) or lithium tris (oxalato) phosphate (LiTOP) or mixtures thereof.

The at least partial reformation of the SEI layer on electrochemical active material then takes place during a first charging step. It is according to the invention to accompany the at least partially new formation of the SEI layer on the electrochemical active material by Anwalzmaßnahmen.

This has the advantage that this results in a more compact and compact SEI layer - compared to an SEI layer whose formation process was not guided by Anwalzmaßnahmen - in which the ingrowth of lithium metal spikes, dendrites, or whiskers is difficult. Also, cracking or pore formation within the SEI layer is reduced during operation of the electrochemical cell.

Preferably, the at least one predetermined measure is applied only to the part of the electrochemical active material which shows a corresponding damage. However, the at least one predetermined measure can also be applied to the entire electrochemical active material of the electrode.

In one embodiment, a damaged portion of the electrochemical active material of an electrode is removed. This damaged part is, if possible, treated with at least one predetermined measure, in particular regenerated. It is also conceivable that the damaged part of the electrochemical active material of the electrode is irreversibly damaged, so that no predetermined measure can regenerate the electrochemical active material. In this case, the irreversibly damaged electrochemical active material must be disposed of in accordance with the applicable regulations. Preferably, an electrode pad is placed on the part of the electrode where the (irreversible) damaged electrochemical active material has been removed. The placement of the electrode pad replaces the removed (irreversibly) damaged electrochemical active material.

An "electrode pad" in the sense of the present invention has at least partially electrochemical active material which has been treated by at least one predetermined measure, in particular regenerated. In addition to electrochemical active material which has been treated, in particular regenerated, by at least one predetermined measure, virgin electrochemical active material can be used. But it is also possible that only brand new electrochemical active material in the electrode pad is used. Furthermore, it is possible that the electrode pad has at least one further compound or at least one further substance which is contained in the non-removed electrochemical active material of the electrode. Preferably, the composition of the electrochemical active material contained in the electrode pad substantially corresponds to the composition of the electrochemical active material of the electrode.

In a preferred embodiment, the electrode has a mixture which, in addition to the electrochemical active material, also has at least one further compound or at least one further substance, in particular at least one binder and / or at least one conductivity additive. Furthermore, the electrode pad used also has a mixture which, in addition to the electrochemical active material, has at least one binder and / or at least one conductivity additive in quantitatively and / or qualitatively equal amounts. The electrode mixture and the electrode pad mixture are preferably substantially identical quantitatively and / or qualitatively.

"Substantially" means that at least up to 50%, at least up to 70%, at least up to 90%, at least up to 99%, preferably 100% of the mixture of the electrode is identical to the mixture of the electrode pad.

According to the invention, the electrode pad at least partially at least one binder which is capable of crosslinking and / or at least one additive which is capable of forming an SEI layer, on. Preferably, this binder and / or the additive is located at the edges of the electrode pad.

This has the advantage that in this way the electrode pad can in particular be firmly bonded to the electrode material surrounding the electrode pad, so that the lithium ion migration between the electrochemical active material of the electrode pad and the electrochemical active material of the surrounding electrode material is not hindered.

The binder preferably has reactive groups which by activation, in particular by chemical, UV or thermal activation, are capable of crosslinking, preferably for crosslinking with the binder of the surrounding electrode material. The formation of an SEI layer at the interface between the electrochemical active material of the electrode pad and the electrochemical active material of the surrounding electrode material by the additive takes place during first charging and / or discharging cycles. As a result, the electrode pad "grows" on the surrounding electrode material and is connected to this materially bonded.

Cohesive means in this case that the connection is no longer destructive solvable. The electrode pad can no longer be separated from the surrounding electrode material without destruction. In one embodiment, the at least one predetermined measure is performed in an atmosphere different from the normal breathable ambient air. The atmosphere is preferably in the form of a protective gas atmosphere, which preferably has substantially, particularly preferably more than 90% to 100%, nitrogen gas or argon gas. The protective gas atmosphere preferably has less than 1 ppm of oxygen and / or less than 1 ppm of water.

electrolyte

In one embodiment, the electrochemical cell has at least one electrolyte.

The electrolyte used can be a nonaqueous electrolyte consisting of at least one organic solvent and at least one alkali metal-containing, preferably lithium ion-containing, inorganic or organic salt.

In principle, all solvents known to the person skilled in the art which are used in electrolytes of electrochemical cells can serve as the organic solvent.

Preferably, the organic solvent is selected from ethylene carbonate (EC), propylene carbonate (PC), dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate (DPC), ethyl methyl carbonate (EMC), methyl formate (MF), methyl acrylate (MA), methyl butyrate (MB ), Ethyl acetate (EA), 1,2-dimethoxyethane, γ-butyrolactone, tetrahydrofuran (THF), 2-methyltetrahydrofuran, 1,3-dioxane, sulfulane, ethylmethylsulfone (EMS), tetramethylenesulfone (TMS), butylsulfone (BS), ethylvinylsulfone (EVS), 1-fluoro-2- (methylsulfonyl) benzene (FS), acetonitrile or phosphoric acid esters, or mixtures of these solvents.

Preferably, the alkali ion-containing, preferably lithium-ion-containing salt has one or more counterions selected from AsF ₆ ^- , PF ₆ ^- , PF ₃ (C ₂ F ₅ ) ₃ ^- , PF ₃ (CF ₃ ) ₃ ^- , BF ₄ ^- , BF ₂ (CF ₃ ) ₂ ^- , BF ₃ (CF ₃ ) ^- , [B (COOCOO) ₂ ] ^- , [B (C ₆ H ₅ ) ₄ ] ^- , Cl ^- , Br ^- , AlCl ₄ ^- , CF ₃ SO ₃ ^- , C ₄ F ₉ SO ₃ ^- , [(CF ₃ SO ₂ ) ₃ C] ^- , [(CF ₃ SO ₂ ) ₂ N] ^- , [(C ₂ F ₅ SO ₂ ) N] ^- , [(CN) ₂ N] ^- , ClO ₄ ^- , SiF ₆ ^- , or mixtures thereof.

In one embodiment, ionic liquids may also be used as the solvent. Such "ionic liquids" contain exclusively inside. Preferred cations which may in particular be alkylated are imidazolium, pyridinium, pyrrolidinium, guanidinium, uronium, thiuronium, piperidinium, morpholinium, sulfonium, ammonium and phosphonium cations. Examples of useful anions are halide, tetrafluoroborate, trifluoroacetate, triflate, hexafluorophosphate, phosphinate and tosylate anions.

Examples of ionic liquids which may be mentioned are: N-methyl-N-propyl-piperidinium-bis (trifluoromethylsulfonyl) imide, N-methyl-N-butyl-pyrrolidinium-bis (trifluoromethyl-sulfonyl) -amide, N-butyl-N-trimethyl-ammonium bis (trifluoromethylsulfonyl) imide, triethylsulfonium bis (trifluoromethylsulfonyl) imide, N, N-diethyl-N-methyl-N- (2-methoxyethyl) -ammonium bis (trifluoromethylsulfonyl) -imide.

Preferably, the separator of the electrochemical cell is impregnated with the electrolyte.

Furthermore, the electrolyte may have adjuvants that are commonly used in electrolytes for lithium-ion batteries. For example, these radical scavengers such as biphenyl, flame retardant additives such as organic Phosphoric acid esters or hexamethylphosphoramide, or acid scavengers such as amines.

Furthermore, the electrolyte preferably contains additives preferably phenylene carbonate, fluorine-containing or non-fluorine-containing lithium organoborates, for example lithium difluoro (oxalato) borate (LiDFOB) or lithium bis (oxalato) borate (LiBOB) and fluorine-containing or non-fluorine-containing lithium organophosphates, for example lithium tetrafluoro (oxalato) phosphate (LiTFOP) or lithium tris (oxalato) phosphate (LiTOP), which may affect the formation of the SEI layer on the electrodes.

In one embodiment, the electrolyte is configured as a polymer electrolyte which, in addition to the abovementioned salts, solvents, auxiliaries and additives, has a polymer matrix. The polymer or polymer blend for the polymer matrix may be selected from among the polymers that can be used for separators.

In one embodiment, a polymer electrolyte of a lithium salt and polyethylene oxide is used.

Ionic liquids

Ionic liquids are ionic compounds which are in a liquid state at room temperature. Ionic liquids consist of anions and cations, the size ratio between cations and anions being chosen so that they do not arrange in a crystal lattice at room temperature, whereby a, preferably liquid at room temperature salt can be obtained, which is referred to as ionic liquid. The ionic liquid typically has "large" organic cations, such as the ethylmethylimidazolium cation, and relatively "small" anions, such as the tetrafluoroborate anion. By suitable combination of cations and anions, the properties of the ionic liquid can also be influenced. For example, if a basic anion such as the cyanato anion OCN ^{- is} used, the ionic liquid is also more basic in nature.

Preferably, ionic liquids are used which have cationic imidazole-containing derivatives, in particular the cation ethyl-methyl-imidazolium. Preferred anions can be selected from the group AlCl ₄ , Al ₂ Cl ₇ , F, F × HF, NO ₂ , NO ₃ , BF ₄ , AlF ₄ , PF ₆ , AsF ₆ , SbF ₆ , NbF ₆ , TaF ₆ , WF ₇ , CH ₃ CO ₂ , CF ₃ CO ₂ , C ₃ F ₇ CO ₂ , CH ₃ SO ₃ , CF ₃ SO ₃ , C ₄ F ₉ SO ₃ , (CF ₃ CO) (CF ₃ SO ₃ ) N, CF ₃ SO ₂ ) ₂ N, (CF ₃ SO ₂ ) (C ₂ F ₅ SO ₂ ) N, (C ₂ F ₅ SO ₂ ) ₂ N, (CF ₃ SO ₂ ) ₃ C, (CN) ₂ N, (CN) ₃ C, CF ₃ BF ₃ , C ₂ F ₅ BF ₃ , C ₃ F ₇ BF ₃ , C ₄ F ₉ BF ₃ or mixtures thereof.

electrodes

The term "negative electrode" means according to the invention that the electrode emits electrons when connected to a consumer, for example an electric motor. Thus, according to this convention, the negative electrode is the anode.

Preferably, the negative electrode has at least one electrochemical active material which is suitable for incorporation and / or removal of redox components, in particular of lithium ions.

In one embodiment, the electrochemical active material of the negative electrode is selected from amorphous graphite, crystalline graphite, mesocarbon, doped carbon, fullerenes, graphene, carbonaceous materials, lithium metal, lithium metal alloys, titanates, silicates, silicon, silicon alloys, tin, tin alloys, Niobium pentoxide or mixtures thereof.

Preferably, in addition to the electrochemical active material, the negative electrode also has at least one further additive, preferably an additive for increasing the conductivity, for example based on carbon, for example carbon black, and / or a redox-active additive which, if the electrochemical cell is overcharged, destroys the electrochemical active material reduced, preferably minimized, preferably prevented.

Preferably, the negative electrode has a metallic substrate. Preferably, this metallic substrate is at least partially coated with electrochemical active material.

In one embodiment, the negative electrode comprises a binder capable of enhancing adhesion between electrochemical active material and a metallic substrate. Preferably, such a binder comprises a polymer, preferably a fluorinated polymer, preferably polyvinylidene fluoride, which is sold under the trade names Kynar ^® or Dyneon ^®, polyethylene oxide, polyethylene, polypropylene, polytetrafluoroethylene, polyacrylate, ethylene- (propylene-diene monomer) copolymer ( EPDM) and mixtures and copolymers thereof.

The term "positive electrode" means that the electrode receives electrons when connected to a consumer, such as an electric motor. Thus, according to this convention, the positive electrode is the cathode.

Preferably, the positive electrode of the electrochemical cell has at least one electrochemical active material which is suitable for incorporation and / or removal of redox components, in particular of lithium ions.

In one embodiment, the electrochemical active material of the positive electrode is selected from at least one oxide, preferably a mixed oxide, which has one or more elements selected from nickel, manganese, cobalt, aluminum, phosphorus, iron or titanium.

In one embodiment, the positive electrode comprises a compound having the formula LiMPO ₄ wherein M is at least one transition metal cation, preferably a transition metal cation of the first series of transition metals of the Periodic Table of the Elements.

The at least one transition metal cation is preferably selected from the group consisting of manganese, iron, nickel, cobalt or titanium or a combination of these elements. The compound preferably has an olivine structure, preferably parent olivine, with iron or cobalt being particularly preferred, preferably LiFePO ₄ or LiCoPO ₄ . However, the compound may also have a structure different from the olivine structure.

In a further embodiment, the positive electrode comprises an oxide, preferably a transition metal oxide, or a transition metal mixed oxide, preferably of the spinel type, preferably a lithium manganate, preferably LiMn ₂ O ₄ , a lithium cobaltate, preferably LiCoO ₂ , or a lithium Nickelate, preferably LiNiO ₂ , or a mixture of two or three of these oxides. However, the oxides can also be different from the spinel type.

Further preferably, the positive electrode in addition to the aforementioned transition metal oxides or exclusively a lithium transition metal mixed oxide containing manganese, cobalt and nickel, preferably a lithium cobalt manganate, preferably LiCoMnO ₄ , preferably a lithium nickel manganate, preferably LiNi _{0 , 5} Mn _1.5 O ₄ , preferably a lithium-nickel-manganese-cobalt oxide, preferably LiNi _0.33 Mn _0.33 Co _0.33 O ₂ , or a lithium-nickel-cobalt oxide, preferably LiNiCoO ₂ , which can not be in the spinel type or in the spinel type.

Preferably, in addition to the electrochemical active material, the positive electrode also has at least one further additive, preferably an additive for increasing the conductivity, for example based on carbon, for example carbon black, and / or a redox-active additive which, if the electrochemical cell is overcharged, destroys the electrochemical active material reduced, preferably minimized, preferably prevented.

Preferably, the positive electrode comprises a binder capable of enhancing adhesion between electrochemical active material and a metallic substrate. Preferably, such a binder comprises a polymer, preferably a fluorinated polymer, preferably polyvinylidene fluoride, which is sold under the trade names Kynar ^® or Dyneon ^®, polyethylene oxide, polyethylene, polypropylene, polytetrafluoroethylene, polyacrylate, ethylene- (propylene-diene monomer) copolymer ( EPDM) and mixtures and copolymers thereof.

Preferably, the positive electrode has a metallic substrate. Preferably, this metallic substrate is at least partially coated with electrochemical active material.

The term "metallic substrate" in the sense of the present invention preferably relates to that component of an electrochemical cell which is known as "electrode carrier" and "collector". In the present case, the metallic substrate is suitable for applying electrochemical active composition and is essentially of a metallic nature, preferably of a completely metallic nature.

Preferably, at least one electrode has at least partially a metallic substrate. Preferably, this metallic substrate is at least partially designed as a film or as a network structure or as a fabric, preferably comprising a metal.

In one embodiment, a metallic substrate comprises copper or a copper-containing alloy. In a further embodiment, a metallic substrate comprises aluminum. In one embodiment, the metallic substrate can be configured as a film, mesh structure or fabric, which preferably comprises at least partially plastics.

Preferably, up to 30%, preferably up to 50%, preferably up to 70%, preferably up to 100%, of the total surface of a metallic substrate has at least one layer which has at least one electrochemical active material which is suitable for incorporation and / or removal of lithium ions suitable is.

separator

In one embodiment, a separator is used which separates the positive electrode from the negative electrode and is not or only poorly electron-conducting, and which consists of a at least partially permeable carrier consists. The support is preferably coated on at least one side with an inorganic material. As at least partially permeable carrier is preferably an organic material is used, which is preferably designed as a non-woven fabric.

The organic material, which preferably comprises a polymer, and more preferably one or more polymers selected from polyethylene terephthalate (PET), polyolefin or polyetherimide, is coated with an inorganic, preferably ion-conducting material, which is more preferably in a temperature range of -40 ° C is at least 200 ° C ion conducting, and preferably at least one compound selected from the group of oxides, phosphates, silicates, titanates, sulfates, aluminosilicates with at least one of zirconium, aluminum, lithium and more preferably zirconium oxide.

The inorganic, ion-conducting material of the separator preferably has particles with a size diameter below 100 nm, preferably from 0.5 to 7 μm, preferably from 1 to 5 μm, preferably from 1.5 to 3 μm.

In one embodiment, the separator has a porous inorganic coating on and in the nonwoven, the aluminum oxide particles having an average particle size of from 0.5 to 7 μm, preferably from 1 to 5 μm, and very particularly preferably from 1.5 to 3 μm, which are bonded to an oxide of the elements Zr or Si.

In order to achieve the highest possible porosity, preferably more than 50% by weight and more preferably more than 80% by weight of all particles are within the abovementioned limits of average particle size. Preferably, the maximum particle size is preferably 1/3 to 1/5 and more preferably less than or equal to 1/10 of the thickness of the nonwoven fabric used.

Suitable polyolefins are preferably polyethylene, polypropylene or polymethylpentene. Particularly preferred is polypropylene. The use of polyamides, polyacrylonitriles, polycarbonates, polysulfones, polyethersulfones, polyvinylidene fluorides, polystyrenes as organic carrier material is also conceivable. It is also possible to use mixtures of the polymers.

A separator with PET as carrier material is commercially available under the name Separion ^® . It can be made by methods such as those in the EP 1 017 476 are disclosed.

The term "nonwoven web" means that the polymers are in the form of nonwoven fibers (non-woven fabric). Such nonwovens are known from the prior art and / or can be produced by the known methods, for example by a spunbonding process or a meltblown process such as, for example, in US Pat DE 195 01 271 A1 referenced.

Preferably, the separator comprises a nonwoven having an average thickness of 5 to 30 microns, preferably from 10 to 20 microns. Preferably, the fleece is flexible. Preferably, the nonwoven fabric has a homogeneous pore radius distribution, preferably at least 50% of the pores have a pore radius of 75 to 100 μm. Preferably, the web has a porosity of 50%, preferably from 50 to 97%.

"Porosity" is defined as the volume of the web (100%) minus the volume of the fibers of the web (corresponds to the fraction of the volume of the web that is not filled by material). The volume of the fleece can be calculated from the dimensions of the fleece. The volume of the fibers results from the measured weight of the fleece considered and the density of the polymer fibers. The large porosity of the web also allows for a higher porosity of the separator, therefore a higher uptake of electrolytes with the separator can be achieved.

In a further embodiment, the separator consists of a polyethylene glycol terephthalate, a polyolefin, a polyetherimide, a polyamide, a polyacrylonitrile, a polycarbonate, a polysulfone, a polyethersulfone, a polyvinylidene fluoride, a polystyrene, or mixtures thereof. Preferably, the separator consists of a polyolefin or of a mixture of polyolefins. Particularly preferred in this embodiment is then a separator which consists of a mixture of polyethylene and polypropylene.

Preferably, such separators have a layer thickness of 3 to 14 .mu.m.

The polymers are preferably in the form of fiber webs, wherein the polymer fibers preferably have an average diameter of 0.1 to 10 microns, preferably from 1 to 4 microns.

The term "mixture" or "mixture" of the polymers in the context of the present invention means that the polymers are preferably in the form of their nonwovens, which are bonded together in layers. Such nonwovens or nonwoven composites are, for example, in EP 1 852 926 disclosed.

In a further embodiment of the separator, this consists of an inorganic material. Preferably, the inorganic material used are oxides of magnesium, calcium, aluminum, silicon and titanium, as well as silicates and zeolites, borates and phosphates. Such materials for separators and processes for the preparation of the separators are in EP 1 783 852 disclosed. In a preferred embodiment of this embodiment of a separator, the separator consists of magnesium oxide.

In a further embodiment of the separator 50 to 80 wt .-% of the magnesium oxide by calcium oxide, barium oxide, barium carbonate, lithium, sodium, potassium, magnesium, calcium, barium phosphate or by lithium, sodium, potassium borate, or Mixtures of these compounds, be replaced.

The separators of this embodiment preferably have a layer thickness of 4 to 25 μm.

Also according to the invention is a method for the treatment, in particular for the regeneration of electrochemical active material by at least one predetermined measure.

In an optional first step, at least one provided, damaged electrode is examined for damage, in particular with the aid of suitable methods or devices such as microscopes or X-ray methods.

In an optional subsequent step, the electrochemical active material of the electrode is at least partially separated from any further contained substances or compounds, in particular from the binder or conductivity additive.

• • zumindest teilweise Verjüngung der SEI-Schicht durch mechanische Arbeit
• • zumindest teilweises Entfernen der SEI-Schicht unter Verwendung geeigneter Lösemittel
• • Behandlung mit mindestens einer SEI-Schicht-bildenden und/oder SEI-Schicht-unterstützenden Substanz, insbesondere mit mindestens einem Elektrolyt und/oder mindestens einem Additiv.

In a further, non-optional step, at least one predetermined measure is applied in particular to the electrochemical active material of the at least one electrode, which has the goal of at least partially treating the electrochemical active material in such a way that the electrochemical active material is again used in an electrode of an electrochemical cell can come, in particular so was regenerated. This is achieved according to the invention by an at least partial reformation and / or renewal of the SEI layer located on the surface of the electrochemical active material to be treated by at least one predetermined measure. The at least one predetermined measure is preferably selected from:

• • at least partial rejuvenation of the SEI layer by mechanical work
• At least partial removal of the SEI layer using suitable solvents
• Treatment with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive.

In a subsequent optional step, the renewed with at least one predetermined measure, especially regenerated electrochemical active material may be subjected to further treatments, in particular dried and / or with other compounds and / or substances, in particular binder and / or electrolyte and / or solvents and / or Conductive additive and / or optionally brand new electrochemical active material are mixed.

Furthermore, according to the invention is a method for assembling an electrochemical cell according to the invention.

In a first, non-optional step, provided by at least one predetermined measure, in particular renewed electrochemical active material is provided.

In an optional second step, the electrochemical active material provided in the first step is mixed with further substances and / or compounds, in particular at least one binder and / or solvent and / or conductivity additive and / or electrolyte and / or optionally brand-new electrochemical active material.

This may be followed by a step in which the electrochemical active material soft possibly mixed with at least one further substance and / or at least one further compound is applied to a metallic substrate. In one embodiment, electrode material is already present on the metallic substrate, and an electrode pad to be applied has the, by at least a predetermined measure, treated, in particular regenerated electrochemical active material.

In a further step, at least one electrode thus produced is joined together with at least one second electrode and an electrically insulating layer located therebetween, in particular a separator or a polymer electrolyte. In one embodiment, the second electrode also has, by at least one predetermined measure treated, in particular regenerated electrochemical active material.

Preferably, the electrochemical cell according to the invention can be operated at ambient temperatures of -40 to + 100 ° C.

Preferred discharge currents of an electrochemical cell according to the invention are greater than 100 A, preferably greater than 200 A, preferably greater than 300 A, more preferably greater than 400 A.

The electrochemical cell according to the invention can be used for supplying energy to mobile information devices, tools, electrically powered automobiles, hybrid-powered automobiles and stationary energy storage devices.

QUOTES INCLUDE IN THE DESCRIPTION

This list of the documents listed by the applicant has been generated automatically and is included solely for the better information of the reader. The list is not part of the German patent or utility model application. The DPMA assumes no liability for any errors or omissions.

Cited patent literature

• DE 102009054016 [0007]
• US 201010068605 [0007]
• EP 1017476 [0118]
• DE 19501271 A1 [0119]
• EP 1852926 [0125]
• EP 1783852 [0126]

Claims (12)

Electrochemical cell comprising at least one negative electrode and at least one positive electrode, wherein the at least one negative electrode and / or the at least one positive electrode comprises electrochemical active material which is capable of a "solid electrolyte interface", ie an SEI layer, on at least Part of the surface of the at least one negative electrode and / or the at least one positive electrode, characterized in that the electrochemical active material has been treated, at least in part, by at least one predetermined measure which is not charging or discharging an electrochemical cell; / or re-training of the SEI layer. An electrochemical cell according to claim 1, characterized in that the at least one predetermined measure is selected from: At least partial rejuvenation of an SEI layer by mechanical force and / or At least partially removing the SEI layer using at least one solvent and / or Treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive. Electrochemical cell according to claim 2, characterized in that the additive is selected from phenylene carbonate, fluorine-containing or non-fluorine-containing lithium organoborates, in particular lithium difluoro (oxalato) borate (LiDFOB) or lithium bis (oxalato) borate (LiBOB) and fluorine-containing or not fluorine-containing lithium organophosphates, in particular lithium tetrafluoro (oxalato) phosphate (LiTFOP) or lithium tris (oxalato) phosphate (LiTOP). Electrochemical cell according to claim 2, characterized in that the mechanical force has at least one abrasive process, in particular shaving and / or removal and / or abrasion and / or Abschmirgeln. Electrochemical cell according to claim 2, characterized in that the at least one solvent is selected from polar organic solvents, non-polar organic solvents, or ionic liquids. Electrochemical cell according to at least one of the preceding claims, characterized in that the electrochemical active material has been irreversibly removed from an electrochemical cell which has been subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle is preferably not for the purpose of conditioning the electrochemical cell was carried out. An electrochemical active material which has already been subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle has preferably not been carried out for the purpose of conditioning the electrochemical cell, obtainable by employing at least one predetermined measure with respect to the electrochemical active material, wherein the at least one predetermined measure is not charging or discharging an electrochemical cell and involves renewal and / or reformation of the SEI layer. Electrochemical active material according to claim 7, characterized in that the at least one predetermined measure is selected from: selected from: At least partial rejuvenation of an SEI layer by mechanical force and / or At least partially removing the SEI layer using at least one solvent and / or Treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive. Electrochemical active material according to claim 6 or 7, characterized in that the electrochemical active material has been irreversibly removed from an electrochemical cell which has been subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle is preferably not carried out for the purpose of conditioning the electrochemical cell has been. An electrochemical active material according to any one of claims 7 to 9 for use in electrodes of electrochemical cells. Method for the treatment, in particular for the regeneration of electrochemical active material by at least one predetermined measure, is preferably selected from: • at least partial rejuvenation of an SEI layer by mechanical force and / or • at least partial removal of the SEI layer using at least one solvent and / or treatment of the electrochemical active material with at least one SEI-layer-forming and / or SEI-layer-supporting substance, in particular with at least one electrolyte and / or at least one additive. wherein the electrochemical active material has been irreversibly removed from an electrochemical cell subjected to at least one charge and discharge cycle, wherein the at least one charge and discharge cycle has preferably not been carried out for the purpose of conditioning the electrochemical cell. Use of the electrochemical cell according to any one of claims 1 to 6 for supplying power to mobile information devices, tools, electrically powered automobiles, hybrid-powered automobiles and stationary energy storage devices.