RU2788178C1 - Battery cell - Google Patents

Abstract

FIELD: electrical engineering.

SUBSTANCE: invention relates to the field of electrical engineering, namely to a battery cell containing an electrolyte based on SO₂. An increase in the energy density of the battery while maintaining the stability of the electrolyte is a technical result of the invention, which is achieved due to the fact that the element (2, 20, 40) of the battery containing the active metal, at least one positive electrode (4, 23, 44) with a discharge element (26), at least one a negative electrode (5, 22, 45) with a discharge element (27) containing lithium metal, the housing (1, 28) contains an electrolyte based on SO₂ and at least one first conductive salt of formula (1)

where M is a metal selected from a group consisting of alkali metals, alkaline earth metals, zinc and aluminum, where x is an integer from 1 to 3, the substituents R ¹, R ², R ³, R ⁴ are selected independently from each other from a group consisting of C₁- C₁₀ alkyl, C₂-C₁₀ alkenyl, C ₂-C₁₀ alkynyl, C₃-C₁₀ cycloalkyl, C₆-C₁₄ aryl and C₅-C₁₄ heteroaryl; Z means aluminum or boron.

EFFECT: present invention enables to increase the energy density of a battery cell while maintaining the stability of the electrolyte.

29 cl, 16 dwg, 1 tbl, 5 ex

Description

The invention relates to a battery cell containing an electrolyte based on SO ₂ .

Battery cells are of great importance for many areas of technology. They are often used in applications where only small battery cells with relatively low current are required, such as when using mobile phones. However, there has also been an increased demand for larger battery cells for high-energy applications, with ultra-large energy storage in the form of battery cells for electric vehicle drive being of particular importance.

An important requirement for such battery cells is high energy density. This means that the battery cell must have as much electrical energy as possible per unit weight and volume. In this case, lithium as the active metal has proven to be particularly preferred. Lithium is the lowest atomic metal and therefore has a maximum theoretical specific capacitance of 3.884 mA. h/g It is the most electronegative metal (-3.10V vs. Standard Hydrogen Electrode (SHE)), resulting in maximum cell voltage with respect to that positive electrode. In addition, it is the lightest metal (0.54 g/cm ³ ), which makes it possible to reach the maximum gravimetric energy density (Wh/kg) or specific energy density (W/l).

The active metal of a battery cell is a metal whose ions, during charging or discharging the cell, move in the electrolyte towards the negative or positive electrode, participating there in electrochemical processes. These electrochemical processes lead to the direct or indirect donation of electrons to an external electrical circuit or to the absorption of electrons from an external electrical circuit. Battery cells with lithium as the active metal are also called lithium cells. Positive electrodes of lithium cells are made in the form of switching electrodes. The term "switch-on electrode" in the sense of the present invention refers to electrodes containing a crystal structure into which ions of the active material are introduced and exited during operation of the lithium cell. This means that electrode processes can occur not only on the surface of the electrodes, but and within the crystal structure. The positive electrode consists, for example, of lithium cobalt oxide (LiCoO ₂ ). During charging of the lithium cell, active metal ions exit the positive electrode and deposit on the negative electrode as lithium metal. When a lithium cell is discharged, the process is reversed.

The electrolyte is also an important functional element of any battery cell. It contains in most cases a solvent or mixture of solvents and at least one conductive salt. For example, solid electrolytes or ionic liquids do not contain solvents, but only a conductive salt that increases the electrical conductivity of the electrolyte. The electrolyte contacts the positive and negative electrodes of the battery cell. At least one conducting salt ion (anion or cation) has such a mobility in the electrolyte that, as a result of ionic conduction, the charge transfer between the electrodes necessary for the functioning of the battery cell can take place. Starting from a certain upper battery cell voltage, the electrolyte decomposes due to electrochemical oxidation. This process often leads to the irreversible destruction of the electrolyte components and consequently to the failure of the battery cell. Also, recovery processes can cause decomposition of the electrolyte, starting from a certain lower cell voltage. To prevent these processes, the positive and negative electrodes are selected so that the cell voltage is lower or higher than the electrolyte decomposition voltage. Thus, the electrolyte determines the voltage range in which the battery cell can be reversibly operated, i.e. repeatedly charged and discharged.

Lithium cells known from the prior art contain an electrolyte consisting of an organic solvent or a mixture of organic solvents and a conductive salt dissolved therein. Such a conductive salt is a lithium salt, such as lithium hexafluorophosphate (LiPF ₆ ). The solvent mixture may contain, for example, ethylene carbonate (EC). Electrolyte LP57, having a composition of 1 M LiPF ₆ in EC : EMC (ethyl methyl carbonate) 3 : 7 (EC:EMC), is an example of such an electrolyte. Due to the presence of an organic solvent or a mixture of organic solvents, such lithium cells are also referred to as organic lithium cells.

Involuntary recharge of organic lithium cells leads to irreversible decomposition of electrolyte components. When this occurs, oxidative decomposition of the organic solvent and/or conductive salt on the surface of the positive electrode. The heat of reaction generated during this decomposition and the resulting gaseous products are the cause of the subsequent so-called "thermal breakdown" and the resulting destruction of the organic lithium cell. In the vast majority of charging protocols for such lithium cells, the cell voltage appears as an indicator of the end of charging. At the same time, accidents due to thermal runaway are especially likely in the case of using a set of multi-cell batteries in which several organic lithium cells with a mismatched capacity are connected in series. Also, the reductive decomposition of the organic electrolyte at the negative electrode of the lithium cell is irreversible. Organic solvents are not thermodynamically stable with respect to lithium or lithium accumulated in carbon (Li _x C ₆ ). However, many solvents form a passivating film on the surface of the negative electrode. This film spatially separates the solvent from the electrode, but is ion-conductive and thus allows the passage of lithium ions. The passivation film, the so-called ''Solid Electrolyte Interphase (TEM)'', gives the system stability, enabling the production of lithium battery cells. During the formation of a solid electrolyte interface (TEM), lithium is incorporated into the passivation film. This process is irreversible and is therefore considered a loss of capacity.

The irreplaceable loss of capacitance, also called capacitance of the coating layer, depends on the composition of the electrolyte used and the electrodes used. In organic lithium cells, the decomposition of the electrolyte and the formation of layers containing lithium ions often occurs during the subsequent operation of the lithium cell and causes a loss of capacity and therefore a reduction in the service life of the battery cell. Capacitance losses may also occur during storage of charged lithium cells. This so-called self-discharge can be based on both irreversible processes (electrolyte decomposition) and reversible processes in which lithium accumulated in the negative electrode passes into the electrolyte solution and can be used again during subsequent charging.

Therefore, organic lithium cells are problematic in terms of their durability and long-term operational reliability. Reliability risks are also caused, in particular, by the flammability of the organic solvent or mixture of organic solvents. If an organic lithium cell ignites or even explodes, then metallic lithium forms a highly reactive substance, and an organic electrolyte solvent is a combustible material. Additional measures are needed to eliminate such risks. A prior art improvement involves the use of a sulfur dioxide (SO ₂ ) based electrolyte instead of an organic electrolyte for battery cells. Battery cells containing an electrolyte based on SO ₂ are characterized, among other things, by high ionic conductivity. The term "SO ₂ -based electrolyte" is to be understood as an electrolyte in which SO ₂ is present not only as an additive at a low concentration, but also in which the mobility of the ions of the conductive salt contained in the electrolyte and causing charge transfer is ensured, at least, partly, mostly or even entirely due to SO ₂ . Hence SO ₂ serves as a solvent for the conductive salt. This conductive salt can form a solvate complex with gaseous SO ₂ , wherein the SO ₂ binds and the vapor pressure drops markedly compared to pure SO ₂ . Electrolytes with low vapor pressure are formed. Such electrolytes based on SO ₂ have the advantage of non-combustibility compared to the organic electrolytes described above. Reliability risks caused by the flammability of the electrolyte can therefore be prevented.

The use of lithium metal as an active metal for the negative electrode of a battery cell introduces various problems. During the charging process, lithium is not deposited uniformly, but in the form of dendrites. The uncontrolled growth of lithium dendrites leads to the accumulation of the most reactive metal with a large surface area and can cause safety-critical conditions. The thermodynamic instability of lithium metal causes inevitable and constant reactions between this lithium and the electrolyte. As a result, undesirably thick passivating layers are formed on the surface of lithium metal, which consume lithium and electrolyte components. As a result, the internal resistance increases and the service life of the lithium battery cell is shortened. Upon repeated charging and discharging, significant volumetric and morphological changes can occur within the lithium metal anode. The passivation films (TEMs) mentioned above are too unstable to completely prevent such significant changes. For both lithium cells with organic electrolyte solutions and cells with SO ₂ based electrolytes, solutions are being sought for solutions to the above problems in connection with lithium metal anodes.

Source Authors (V1): ''Dendrite-Free Lithium Deposition Induced by Distributed Lithium Ions for Efficient Lithium Metal Batteries'', Xin-Bing Cheng, Ting-Zheng Hou, Rui Zhang, Hong-Jie Peng, Chen-Zi Zhao, Jia-Qi Huang Zhang; Adv. mater. 2016, 28, 2888-2895'' report on a rechargeable battery with lithium metal and organic electrolyte. To obtain a dendrite-free anode from lithium metal, they used a three-dimensional glass fiber cloth with a large number of polar groups to deposit lithium.

US 7,901,811 B2 (below V2) describes a lithium metal cell with an SO ₂ based electrolyte containing a conductive lithium tetrachloroaluminate salt (LiAICl ₄ ). To prevent the disadvantages associated with dendritic deposition, a porous structure formed by particles of a solid material is proposed, made and arranged in such a way that lithium deposited during charging of a lithium metal element penetrates from the surface of the spark gap into the pores of the porous structure and is deposited there again.

A disadvantage, which also occurs in this SO ₂ -based electrolyte, among other things, is that possible hydrolysis products formed in the presence of residual water react with the components of the battery cell and, as a result, undesirable by-products are created. Therefore, when manufacturing such battery cells with an SO ₂ based electrolyte, care must be taken to minimize residual water in the electrolyte and battery cell components.

Another problem inherent in electrolytes based on SO ₂ is that many conductive salts, in particular those known from organic lithium cells, are insoluble in SO ₂ . It has been measured that SO ₂ is a poor solvent for many conductive salts, such as lithium fluoride (LiF), lithium bromide (LiBr), lithium sulfate (Li ₂ SO ₄ ), lithium bis(oxalate) borate (LiBOB), lithium hexafluoroarsenate (LiAsF ₆ ), lithium tetrafluoroborate (LiBF ₄ ), trilithium hexafluoroaluminate (Li ₃ AIF ₆ ), lithium hexafluoroantimonate (LiSbF ₆ ), lithium difluoro(oxalate) borate (LiBF ₂ C ₂ O ₄ ), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI ), lithium metaborate (LiBO ₂ ), lithium aluminate (LiAIO ₂ ), lithium triflate (LiCF ₃ SO ₃ ), and lithium chlorosulfonate (LiSO ₃ Cl). The solubility of these conductive salts in SO ₂ is about 10 ^-2 -10 ^-4 mol/l (see Table 1). At such low salt concentrations, it should be borne in mind that in any case only a slight solubility will occur, which is not sufficient for efficient operation of the battery cell.

To further improve the applicability and properties of battery cells containing SO ₂ based electrolyte, the present invention is based on the task of providing a battery cell with SO ₂ based electrolyte, which, in comparison with prior art battery cells:

- has improved electrical working

characteristics, in particular, high energy density;

- contains a stable coating layer on the negative electrode, while the capacity of this layer should be low and during subsequent operation there should be no reductive decomposition of the electrolyte on the negative electrode;

- contains an electrolyte based on SO ₂ , which contributes to the uniform deposition of lithium metal,

- contains an electrolyte based on SO ₂ , which has a good dissolving power for conductive salts, and therefore serves as a good conductor of ions and an electronic insulator, which facilitates the transport of ions and minimizes self-discharge,

- contains an SO ₂ based electrolyte that is inert to other battery cell components such as separators, electrode materials, and cell packaging materials,

- is resistant to other undue influences, such as electrical, mechanical or thermal;

- contains an electrolyte based on SO ₂ , characterized by increased resistance to residual amounts of water in the components of the battery cells;

- has a wide electrochemical range, as a result of which there is no oxidative decomposition of the electrolyte on the positive electrode;

- has an improved ability to recharge and deep discharge, as well as less self-discharge and

- has an increased service life, in particular, a large number of charge and discharge cycles.

Such battery cells must have, in particular, very good electrical energy and performance characteristics, high operational reliability and durability, in particular, a large number of useful charge and discharge cycles without electrolyte decomposition during the operation of the battery cells.

The goal is achieved by performing a battery cell with the characteristics of paragraph 1 of the claims. In paragraphs 2-29 of the claims describes the preferred options for the development of the battery cell according to the invention.

The battery cell according to the invention contains an active metal, at least one positive electrode with a discharge cell, at least one negative electrode with a discharge cell, a housing and an electrolyte. lithium as active material.

The electrolyte is based on SO ₂ and contains at least one first conductive salt. This salt corresponds to formula (1):

In the formula (I) means: M is a metal selected from the group consisting of: alkali metals, alkaline earth metals, zinc and aluminum, x is an integer from 1 to 3. Substituents R ¹ , R ² , R ³ and R ⁴ , independently of each other, selected from the group consisting of C ₁ -C ₁₀ alkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₃ -C ₁₀ cycloalkyl, C ₆ -C ₁₄ aryl and C ₅ -C ₁₄ heteroaryl.

The central atom Z is either aluminum or boron. The electrolyte used in the battery cell according to the invention and based on SO ₂ contains SO ₂ not only as an additive in a small concentration, but also in concentrations that ensure the mobility of the ions of the first conductive salt contained in the electrolyte and responsible for the transport of ions , at least partially, mostly or even completely through SO ₂ . The first conductive salt is dissolved in the electrolyte and has very good solubility in it. Together with gaseous SO ₂ it is able to form a liquid solvate complex in which SO ₂ binds. In this case, the vapor pressure of the liquid solvate complex is markedly reduced compared to pure SO ₂ and electrolytes with low vapor pressure are formed. However, it is also within the scope of the invention that, depending on the chemical structure of the first conductive salt of the formula (I), the vapor pressure may not decrease when the electrolyte according to the invention is prepared. In such a case, it is preferable that the preparation of the electrolyte according to the invention is carried out at low temperature or under pressure. The electrolyte may also contain several conductive salts of formula (I), which differ in their chemical structure.

The term "C ₁ -C ₁₀ alkyl" includes in the sense of the present invention linear or branched saturated hydrocarbon groups containing from one to ten carbon atoms. These include in particular methyl, ethyl, n-propyl, isopropyl, n-butyl, sec, butyl, iso-butyl, tert, butyl, n-pentyl, iso-pentyl, 2,2-dimethylpropyl, n-hexyl, iso-hexyl, 2-ethylhexyl, n-heptyl, iso-heptyl, n-octyl, iso-octyl, n-nonyl, n-decyl, etc.

The term "C ₂ -C ₁₀ alkenyl" includes, in the sense of the present invention, unsaturated linear or branched hydrocarbon groups containing from two to ten carbon atoms, the hydrocarbon groups having at least one C-C double bond. These include, in particular, ethenyl, 1-propenyl, 2-propenyl, 1-n-butenyl, 2-n-butenyl, iso-butenyl, 1-pentenyl, 1-hexenyl, 1-heptenyl, 1-octenyl, 1- nonenyl, 1-decenyl, etc.

The term "C ₂ -C ₁₀ alkynyl" includes, in the sense of the present invention, unsaturated linear or branched hydrocarbon groups containing from two to ten carbon atoms, the hydrocarbon groups having at least one C-C triple bond. These include, in particular, ethynyl, 1-propynyl, 2-propynyl, 1-n-butynyl, 2-n-butynyl, isobutynyl, 1-pentynyl, 1-hexynyl, 1-heptynyl, 1-octynyl, 1-noninyl, 1-decynyl, etc.

The term "C ₃ -C ₁₀ cycloalkyl" includes in the sense of the present invention cyclic saturated hydrocarbon groups containing from three to ten carbon atoms. These include, in particular, cyclopropyl, cyclobutyl, cyclopentyl, cyclohexyl, cyclohepsil, cyclohexyl, cyclononyl and cyclodecanyl.

The term "C ₆ -C ₁₄ aryl" includes in the sense of the present invention aromatic hydrocarbon groups containing from six to fourteen ring carbon atoms. These include in particular phenyl (C ₆ H ₅ group), naphthyl (C ₁₀ H ₇ group) and anthracyl (C ₁₄ H ₉ group).

The term "C ₅ -C ₁₄ heteroaryl" includes in the sense of the present invention aromatic hydrocarbon groups containing from five to fourteen ring carbon atoms in which at least one hydrocarbon atom is replaced or replaced by a nitrogen, oxygen or sulfur atom . These include, in particular, pyrrolyl, furanyl, thiophenyl, pyrridinyl, pyranyl, thiopyranyl, etc. All the above-mentioned hydrocarbon groups are linked via an oxygen atom to the central atom according to formula (I).

A battery cell with such an electrolyte has the advantage over prior art battery cells with electrolytes that the first conductive salt contained therein has improved resistance to oxidation and is therefore substantially immune to degradation at elevated cell voltages. This electrolyte is resistant to oxidation preferably at least at an upper potential up to 4.0 V, preferably at least at an upper potential up to 4.2 V, preferably at least at an upper potential up to 4.4 V, preferably at least at an upper potential of up to 4.6 V, preferably at least at an upper potential of up to 4.8 V, particularly preferably at an upper potential of up to 5.0 V. Thus, when using such electrolyte in the battery cell, there is only a slight decomposition or even no decomposition of the electrolyte within the operating potential, i.e. in the range between the final charge voltage and the final discharge voltage of both electrodes of the battery cell. As a result, the battery cells can have a final charge voltage of at least 4.0 V, preferably at least 4.4 V, preferably at least 4.8 V, preferably at least at least 5.2 V, preferably at least 5.6 V, particularly preferably at least 6.0 V.

The service life of a battery cell with such an electrolyte is markedly increased compared to a battery cell with an electrolyte known from the prior art.

In addition, a battery cell with such an electrolyte is resistant to low temperatures. At a temperature of, for example, -40° C., 61% of the charged capacity can still be discharged. The electrical conductivity of the electrolyte at low temperatures remains sufficient for the operation of the battery cell.

In addition, a battery cell with such an electrolyte has an increased resistance to residual amounts of water. If the electrolyte still contains small amounts of water (in the range of a few parts per million), then the electrolyte or the first conductive salt forms with water, in comparison with electrolytes based on SO ₂ known from the prior art, hydrolysis products that are noticeably less aggressive with respect to element components. As a result, the absence of water in the electrolyte plays a less significant role compared to prior art SO ₂ based electrolytes. These advantages of the electrolyte according to the invention outweigh the disadvantage due to the fact that the first conductive salt of formula (I) has significantly larger anions compared to the conductive salts known from the prior art. This increased anion size causes, compared to the electrical conductivity of LiAICl ₄ , a lower electrical conductivity of the first conductive salt of formula (I).

negative electrode.

The active material of the negative electrode is lithium metal. This means that lithium is also the active metal of the rechargeable battery. It is deposited when the battery is charged on the discharge element of the negative electrode. This means that the negative electrode, in addition to metallic lithium, also has a discharge element as an active material. According to another preferred embodiment of the battery cell according to the invention, it is provided that the negative electrode has a discharge cell. This means that the negative electrode contains, in addition to the active or interstitial material, also a discharge element. This discharge element is designed to provide the necessary electron-conductive connection of the negative electrode active material. To do this, the discharge element is in contact with the active material involved in the reaction taking place on the negative electrode. When a battery cell is discharged, lithium metal is converted to lithium ions, with the lithium ions moving from the negative electrode to the positive. Since the positive electrode is made in the form of an intercalary electrode, the lithium ions are in the uncharged state of the battery cell, at least partially in the main matrix of the active material of the positive intercalary electrode.

The preferred embodiments of the battery cell according to the invention with respect to the negative electrode are described below.

According to a preferred development of the battery cell according to the invention, it is provided that the electronically conductive negative electrode discharge element in the discharged state of the battery cell does not contain lithium metal. When the battery cell is being charged, lithium metal is deposited on the electronically conductive negative electrode discharge cell. Upon discharging, the lithium metal substantially dissolves completely and enters in the form of ions into the main matrix of the positive electrode active material.

According to another advantageous development of the battery cell, it is provided that the electron-conducting negative electrode discharge element contains lithium metal already before the first charging of the battery cell. During charging of the battery cell, additional lithium metal is deposited on the electron-conducting discharge cell. When discharging, lithium metal completely or partially dissolves and enters in the form of ions into the main matrix of the active material of the positive electrode.

Lithium metal already present on the discharge cell can firstly be deposited on the discharge cell prior to assembly of the battery cell and then integrated into the battery cell together with it. Secondly, lithium metal may be deposited on the negative electrode discharge cell prior to the battery cell being used, i.e. before the first charging and discharging by the previous initializing charging process.

According to a preferred development of the battery cell according to the invention, it is provided that the electron-conducting discharge element of the negative electrode does not contain any metallic lithium before the first charging of the battery cell. When a battery cell is being charged, lithium metal is deposited on the electron-conducting discharge cell. When discharging, lithium metal dissolves completely or partially and enters in the form of ions into the main matrix of the active material of the positive electrode.

According to a preferred development of the battery cell according to the invention, it is provided that the negative electrode discharge cell is made at least in part of a lithium storage material. According to this embodiment, when the battery cell is charged, a portion of the lithium discharged from the electrode reaction is first accumulated in an electron-conducting discharge cell made of lithium storage material. When the battery cell is subsequently charged, lithium metal is deposited on the electron-conducting discharge cell. When discharging, lithium metal completely or only partially dissolves and enters in the form of ions into the main matrix of the active material of the positive electrode.

The lithium storage material can be, for example, an interstitial material in the form of carbon, in particular in the form of graphite. It can also be a material that forms an alloy with lithium, for example, lithium storage metals and metal alloys (for example, Si, Ge, Sn, SnCo9 _x C _y , SnSi _x , etc., preferably silicon) or oxides of lithium storage metals or metal alloys ( eg SnO _x , SiO _x , oxide glasses Sn, Si, etc.) or a carbon-free lithium intercalary material, eg lithium titanates, in particular Li ₄ Ti ₅ O ₁₂ . Also, conversion materials, such as transition metal oxides, can be used as lithium storage materials.

According to a preferred development of the battery element according to the invention, it is provided that the negative electrode discharge element is made flat in the form of a thin metal sheet or a thin metal foil. Preferably, the thin metal foil has a perforated or mesh structure. The flat discharge element may also consist of a metal-coated polymer film. Such metallic coatings have a thickness in the range of 0.1 to 20 µm. The negative electrode active material is preferably deposited on the surface of a thin metal sheet, a thin metal foil or a metal-coated polymer film. The application of the active material can be carried out on the front and/or back side of the flat discharge element. Such flat discharge elements have a thickness in the range from 5 to 50 μm. Preferably, the thickness of the flat discharge element is 10 to 30 µm. When flat discharge elements are used, the total thickness of the negative electrode may be at least 20 µm, preferably at least 40 µm, particularly preferably at least 60 µm. The maximum thickness is at most 200 µm, preferably at most 150 µm, particularly preferably at most 100 µm. The surface-specific capacitance of the negative electrode, referred to the coating on one side, is preferably at least 0.5 mAh/cm ² when using a flat discharge cell in the charged state of the battery cell, and in this sequence the following indicators are preferable : 1 mAh/cm ² , 3 mAh/cm ² , 5 mAh/cm ² , 10 mAh/cm ² , 15 mAh/cm ² , 20 mAh/cm ² , 25 mAh/cm ² .

In addition, there is the possibility that the discharge element can be made three-dimensional in the form of a porous metal structure, in particular in the form of metal foam. The term "three-dimensional porous metal structure" includes any metal structure that extends not only along the length and width of a flat electrode, as occurs with a thin metal sheet or metal foil, but also along its thickness. The three-dimensional porous metal structure is so porous that the active material of the negative electrode, i.e. metal lithium, can be deposited in the pores of the metal structure. The amount of deposited active material determines the charge of the negative electrode. If the discharge element is made three-dimensional in the form of a porous metal structure, in particular in the form of a metal foam, then the thickness of the negative electrode will be preferably at least 0.2 mm, preferably at least 0.3 mm, preferably at least at least 0.4 mm, preferably at least 0.5 mm, particularly preferably at least 0.6 mm. The thickness of the electrodes in this case is noticeably larger compared to the negative electrodes used in organic lithium batteries.

According to another preferred embodiment, it is provided that the surface specific capacity of the negative electrode in the charged state of the battery cell is, when using a three-dimensional discharge cell, in particular in the form of a metal foam, preferably at least 2.5 mAh/cm ² , and in this sequence the following indicators are preferred: 5 mAh/cm ² , 15 mAh/cm ² , 25 mAh/cm ² , 35 mAh/cm ² , 45 mAh/cm ² .

According to another preferred development of the battery cell according to the invention, it is provided that the discharge cell contains a binder. This binder is preferably a fluorinated binder, in particular polyvinylidene fluoride and/or a terpolymer consisting of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. However, a binder is also possible, consisting of a single polymer formed by monomeric structural units of a conjugated carboxylic acid, or from an alkali metal salt, an alkaline earth metal salt or an ammonium salt of a conjugated carboxylic acid, or a combination thereof. Also, the binder may consist of a polymer based on monomeric structural units of styrene and butadiene. In addition, the binder may come from the group of carboxymethyl celluloses. The binder is present in the negative electrode preferably at a concentration of at most 20 wt.%, preferably at most 15 wt.%, preferably at most 10 wt.%, preferably at most 7 wt.%, preferably at most 5 wt.%, particularly preferably not more than 2 wt.%, based on the total weight of the negative electrode. Electrolyte.

The preferred battery cell developments in relation to SO ₂ -based electrolyte are described below.

According to a preferred embodiment of the battery cell, the substituents R ¹ , R ² , R ³ , R ^{4 of} the first conductive salt are independently selected from the group consisting of:

- C ₁ -C ₆ alkyl, preferably C ₂ -C ₄ alkyl, particularly preferably alkyl groups 2-propyl, methyl and ethyl;

- C ₂ -C ₆ alkenyl, preferably C ₂ -C ₄ alkenyl, particularly preferably ethenyl and propenyl alkenyl groups;

- C ₂ -C ₆ alkynyl, preferably C ₂ -C ₄ alkynyl;

- C ₃ -C ₆ cycloalkyl;

- phenyl;

- C ₅ -C ₇ heteroaryl.

In the case of this preferred embodiment of the electrolyte based on SO ₂ , the term "C ₁ -C ₆ alkyl" means linear or branched saturated hydrocarbon groups containing from one to six carbon atoms, in particular methyl, ethyl, n-propyl, isopropyl , n-butyl, sec-butyl, isobutyl, tert-butyl, n-pentyl, isopentyl, 2,2-dimethylpropyl, n-hexyl and isohexyl. Of these, C ₂ -C ₄ alkyls are preferred. Especially preferred are C ₂ -C ₄ alkyl, 2-propyl, methyl and ethyl.

In the case of a preferred embodiment of the electrolyte based on SO ₂ , the term "C ₂ -C ₆ alkenyl" means unsaturated linear or branched hydrocarbon groups containing from two to six carbon atoms, while these hydrocarbon groups have at least one C double bond -FROM. They include in particular ethenyl, 1-propenyl, 2-propenyl, 1-n-butenyl, 2-n-butenyl, isobutenyl, 1-pentenyl and 1-hexenyl, with C ₂ -C ₄ alkenyls being preferred. Especially preferred are ethenyl and 1-propenyl.

In the case of this preferred embodiment of the electrolyte based on SO ₂ , the term "C ₂ -C ₆ alkynyl" means unsaturated linear or branched hydrocarbon groups containing from two to six carbon atoms, while these hydrocarbon groups have at least one triple bond S-S. These include, in particular, ethynyl, 1-propynyl, 2-propynyl, 1-n-butynyl, 2-n-butynyl, isobutynyl, 1-pentynyl and 1-hexynyl. Of these, C ₂ -C ₄ alkynyls are preferred.

In the case of this preferred embodiment of the electrolyte based on SO ₂ the term "C ₃ -C ₆ cycloalkyl" means cyclic saturated hydrocarbon groups containing from three to six carbon atoms. They include in particular cyclopropyl, cyclobutyl, cyclopentyl and cyclohexyl.

In the case of this preferred embodiment of the electrolyte based on SO ₂ the term "C ₅ -C ₇ heteroaryl" means phenyl and naphthyl.

In order to increase the solubility of the first conductive salt in the SO ₂ electrolyte, the substituents R ¹ , R ² , R ³ , R ⁴ are substituted in another preferred embodiment of the battery cell with at least one fluorine atom and/or at least , one chemical group, and this group is selected from the group consisting of C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, C ₂ -C ₄ alkynyl, phenyl and benzyl. The chemical groups C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, C ₂ -C ₄ alkynyl, phenyl, and benzyl have the same properties or chemical structures as the previously described hydrocarbon groups. In this regard, the term "substituted" means that individual atoms or groups of atoms of substituents R ¹ , R ² , R ³ , R ⁴ are replaced by a fluorine atom and/or a chemical group.

Particularly high solubility of the first conductive salt in the SO ₂ -based electrolyte can be achieved when at least one of the substituents R ¹ , R ² , R ³ , R ⁴ is a CF ₃ group or an OSO ₂ CF ₃ group.

In another preferred development of the battery cell, the first conductive salt is selected from the group consisting of:

In order to bring the electrical conductivity and/or other properties of the electrolyte in line with the desired indicator, the electrolyte contains, according to a preferred embodiment of the battery cell according to the invention, at least one second conductive salt, different from the first conductive salt of formula (I). This means that the electrolyte can contain, in addition to the first conductive salt, also the second or second conductive salts, which differ in their chemical composition and chemical structure from the first conductive salt.

In another preferred embodiment of the battery cell according to the invention, the second conductive salt is an alkali metal compound, in particular a lithium compound. The alkali metal or lithium compound is selected from the group consisting of aluminate, halide, oxalate, borate, phosphate, arsenate and gallate. Preferably the second conductive salt is lithium tetrahaloaluminate, in particular LiAICL ₄ .

In addition, according to another preferred embodiment of the battery cell according to the invention, the electrolyte contains at least one additive. This additive is preferably selected from the group consisting of vinylene carbonate and its derivatives, vinylethylene carbonate and its derivatives, methylethylene carbonate and its derivatives, lithium (bis-oxylate)borate, lithium difluoro(oxalate)borate, lithium tetrafluoro(oxalate)phosphate, lithium oxalate, 2 -vinylpyridine, 4-vinylpyridine, cyclic exomethylene carbonates, sultones, cyclic and acyclic sulfonates, acyclic sulfites, cyclic and acyclic sulfinates, organic esters of inorganic acids, acyclic and cyclic alkanes, which (acyclic and cyclic alkanes) have a boiling point at a pressure of 1 atm at least 36°C, aromatic compounds, halogenated cyclic and acyclic sulfonylimides, halogenated cyclic and acyclic phosphate esters, halogenated cyclic and acyclic phosphines, halogenated cyclic and acyclic phosphites, halogenated cyclic and acyclic phosphazenes, halogenated cyclic and acyclic silylamines, halogenated cyclic and acyclic esters, halogenated cyclic and acyclic amides, halogenated cyclic and acyclic anhydrides, and halogenated organic heterocycles.

In a preferred embodiment of a battery cell, the electrolyte has the following composition, based on the total weight of the electrolyte:

(i) 5 - 99.4 wt.% sulfur dioxide,

(ii) 0.6 - 95% by weight of the first conductive salt,

(iii) 0 - 25% by weight of the second conductive salt,

(iv) 0-10 wt% additive.

As mentioned above, not only one first conductive salt of formula (1) and one second conductive salt, but also several first conductive salts of formula (1) and several second conductive salts can be present in the electrolyte. The percentages given above also include, in the latter case, a few first and a few second conductive salts. The concentration of the first conductive salt is 0.01 to 10 mol/l, preferably 0.05 to 10 mol/l, preferably 0.1 to 6 mol/l, particularly preferably 0.2 to 3.5 mol/l , from the total electrolyte volume.

According to another preferred embodiment of the battery cell according to the invention, it is provided that the electrolyte contains at least 0.1 mol SO ₂ , preferably at least 1 mol SO ₂ , preferably at least 5 mol SO ₂ , preferably at least 10 mol SO ₂ , particularly preferably at least 20 mol SO ₂ , per 1 mol of conductive salt. The electrolyte may also contain very high mole fractions of SO ₂ , with a preferred upper limit being 2600 moles SO ₂ per mole of conductive salt, with the upper limits being preferred in this order: 1500, 1000, 500 and 100 moles SO ₂ per 1 mole of conductive salt. The term "per mole of conductive salt" refers here to all the conductive salts contained in the electrolyte. Electrolytes based on SO ₂ with this concentration ratio between SO ₂ and conductive salt have the advantage that they can dissolve a larger amount of conductive salt compared to electrolytes known from the prior art, which are based, for example, on a mixture of organic solvents. Surprisingly, it has been found within the scope of the invention that an electrolyte with a relatively low concentration of conductive salt, despite the increased vapor pressure associated therewith, is preferred, in particular because of its durability over many charging and discharging cycles of the battery cell. The concentration of SO ₂ in the electrolyte affects its electrical conductivity. Therefore, by selecting the SO ₂ concentration, it is possible to match the electrical conductivity of the electrolyte with the intended use of a battery cell with such an electrolyte.

The total content of SO ₂ and the first conductive salt may be more than 50 wt.% of the weight of the electrolyte, preferably more than 60 wt.%, preferably more than 70 wt.%, preferably more than 80 wt.%, preferably more than 85 wt.%, preferably more than 90 wt.%, preferably more than 95 wt.%, preferably more than 99 wt.%.

The electrolyte may contain at least 5 wt.% SO ₂ from the total amount of electrolyte contained in the battery cell, with 20 wt.%, 40 wt.% being preferred. and 60 wt.% SO ₂ . The electrolyte may also contain up to 95 wt.% SO ₂ , with the maximum values of 80 wt.% and 90 wt.% SO ₂ being preferred in this range.

Within the scope of the invention, it is provided that the electrolyte preferably contains only a small percentage of at least one organic solvent or is not present at all. Preferably, the proportion of the organic solvent in the electrolyte, for example in the form of a single solvent or a mixture of several solvents, may not exceed 50% by weight of the electrolyte. Particularly preferred are smaller proportions of at most 40 wt%, at most 30 wt%, at most 20 wt%, at most 15 wt%, at most 10 wt%, at most 5 wt%, or at most 1 wt.% of the weight of the electrolyte. An electrolyte free of organic solvents is also preferred. Due to the presence of only a small proportion of organic solvents, or even their complete absence, the electrolyte is either slightly flammable or non-flammable. This improves the serviceability of a battery cell using such an SO ₂ -based electrolyte. Particularly preferred is an SO ₂ based electrolyte containing substantially no organic solvents.

According to a preferred development of the battery cell, the electrolyte, in relation to its total weight, has the following composition:

(i) 5 - 99.4 wt.% sulfur dioxide,

(ii) 0.6 - 95% by weight of the first conductive salt,

(iii) 0 - 25% by weight of the second conductive salt,

(iv) 0-10 wt.% additive,

(v) 0-50 wt% organic solvent. positive electrode.

The preferred embodiments of the battery cell according to the invention in relation to the positive electrode are described below.

According to a preferred development of the battery cell according to the invention, it is provided that the positive electrode can be charged to at least an upper potential of 4.0 V, preferably to at least a potential of 4.4 V, preferably to at least a potential of 4.8 V, preferably at least up to 5.2 V, preferably at least up to a potential of 5.56 V, particularly preferably at least up to a potential of 6.0 V.

According to a preferred development of the battery cell according to the invention, the positive electrode contains at least one active material. This material can accumulate active metal ions and give off and reabsorb active metal ions during the operation of the battery cell.

According to a preferred development of the battery cell according to the invention, the positive electrode contains at least one intercalary compound. The term ''intercalary compound'' refers in the sense of the present invention to a subset of the previously described intercalation materials. Such an intercalary compound acts as a host matrix with vacancies linked together. Active metal ions can diffuse into these vacancies during the discharge of the battery cell and remain embedded. As part of this introduction of active metal ions, only minor or no structural changes occur in the main matrix.

According to another preferred development of the battery cell according to the invention, the positive electrode contains at least one convertible compound as active material. The term "transformable compound" is understood in the sense of the present invention to be materials which, during electrochemical activity, form other materials, i.e. During the charging and discharging of a battery cell, chemical bonds are broken and re-formed. During absorption or release of active metal ions, structural changes occur in the matrix of the convertible compound.

According to a preferred development of the battery cell according to the invention, the active material has the composition Li _x M' _y M'' _z O _a , which means:

- M' at least one metal selected from the group consisting of the elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn;

- M'' at least one element selected from the group consisting of elements of groups 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16

Periodic system of elements;

- x and y independently of each other, numbers greater than 0;

- z is a number greater than or equal to 0,

- a number greater than 0.

Indices y, z in the composition Li _x M' _y M'' _z O _a refer to the totality of metals and elements, denoted by M' _y M''. If, for example, M' means two metals M' ¹ and M' ² , then it will be valid for the index y: y=y1+y2, while y1 and y2 are the indices of the metals M' ¹ and M' ² . Indices x, y, z, a must be chosen so that the charge neutrality is ensured in the composition. Examples of compounds in which M' means two metals are oxides of lithium-nickel-manganese-cobalt composition Li _x Ni _y1 Mn _y2 Co _z O ₂ where M' ¹ =Ni, M' ² =Mn and M''=Co .

Examples of compounds in which z=0, which therefore do not contain another metal or element M'', are oxides of lithium-cobalt Li _x Co _y O _a . If, for example, M'' includes two elements, firstly a metal in the form of M''1 and, secondly, phosphorus in the form of M'' ² , then it will be valid for the index z: z=z1+z2 , and z1 and z2 are indices of metal M'' ¹ and phosphorus (M'' ² ). Indices x, y, z, and in this case should be chosen so that charge neutrality is achieved within the composition. Examples of compounds in which M'' - metal M'' ¹ and phosphorus in the form of M'' ² are lithium-iron-manganese phosphates Li _x Fe _y Mn _z1 P _z2 O ₄ , where M'=Fe, M'' ¹ =Mn, M'' ² =P and z2=1. In another composition, M'' may include two non-metals, for example, fluorine as M'' ¹ and sulfur as M'' ² . Examples of such compounds are sulfates of lithium-iron-fluorine Li _x Fe _y F _z1 S _z2 O ₄ , where M'=Fe, M'' ¹ =F, M'' ² =P.

According to a preferred development of the battery cell according to the invention, it is provided that M' denotes the metals nickel and manganese, M'' denotes cobalt. In this case, we mean the compositions of the formula Li _x Ni _y1 Mn _y2 Co _z O ₂ (NMC), i.e. oxides of lithium-nickel-manganese-cobalt having the structure of layered oxides. Examples of such active materials from lithium-nickel-manganese-cobalt oxide are LiNi _1/3 Mn _1/3 Co _1/3 O ₂ (NMK111), LiNi _0.6 Mn _0.2 Co _0.2 O ₂ (NMK622) and LiNi _0.8 Mn _0.1 Co _0.1 O ₂ (НМК811). Other lithium-nickel-manganese-cobalt oxide compounds may have the composition LiNi _0.5 Mn _10.3 Co _0.2 O ₂ , LiNi _0.5 Mn _0.25 Co _0.25 O ₂ , LiNi _0.52 Mn _{0 ,32} Co _0.16 O ₂ , LiNi _0.55 Mn _0.30 Co _0.15 O ₂ , LiNi _0.58 Mn _0.14 Co _0.28 O ₂ , LiNi _0.64 Mn _0.18 Co _{0, 18} O ₂ , LiNi _0.65 Mn _0.27 Co _0.08 O ₂ , LiNi _0.7 Mn _0.2 Co _0.1 O ₂ , LiNi _0.7 Mn _0.15 Co _0.15 O ₂ , LiNi _0.72 Mn _0.10 Co _0.18 O ₂ , LiNi _0.76 Mn _0.14 Co _0.10 O ₂ , LiNi _0.86 Mn _0.04 Co _0.10 O ₂ , LiNi _0.90 Mn _{0 .05} Co _0.05 O ₂ , LiNi _0.95 Mn _0.025 Co _0.025 O ₂ or a combination thereof.

These compounds can be used to make positive electrodes for battery cells with cell voltages above 4.6 V.

According to another preferred development of the battery cell according to the invention, it is provided that the active material is a metal oxide rich in lithium and manganese. Such materials are described by the following formulas: Li _x Mn _y M'' _z O _a . M' in the above formula Li _x M' _y M'' _z O _a means the metal manganese (Mn). Here, index x means a number that is greater than or equal to 1, index y means a number that is greater than index z or greater than the sum of indices z1+z2+z3, and so on.

If, for example, M'' means two metals M'' ¹ and M'' ² with indices z1 and z2 (for example, Li _1.2 Mn _0.525 Ni _0.175 Co _0. 1O ₂ , where M'' ¹ =Ni, z1=0.175 and M'' ² =Co, z2=0.1), then it will be valid for index y: y>z1+z2. The index z is a number that is greater than or equal to 0, the index a is a number that is greater than 0. The indices x, y, z, a must be chosen so that charge neutrality is achieved within the composition. Metal oxides rich in lithium and manganese can also be described by the formula mLi ₂ MnO ₃ ⋅(1-m)LiM'O ₂ where 0<m<1. Examples of such compounds are Li _1.2 Mn _0.525 Ni _0.175 Co _0.1 O ₂ , Li _1.2 Mn _0.6 Ni _0.2 O ₂ or Li _1.2 Ni _0.13 Co _0.13 Mn _0.54 O ₂ .

According to a preferred development of the battery cell according to the invention, it is provided that the composition has the formula Li _x M' _y M'' _z O ₄ . These compounds have a spinel structure. For example, they mean: M' - cobalt, M'' - manganese. In this case, the active material is lithium-cobalt-manganese oxide (LiCoMnO ₄ ). LiCoMnO ₄ can be used to produce positive electrodes for battery cells according to the invention with cell voltages above 4.6 V. This LiCoMnO ₄ preferably does not contain Mn ³⁺ . In another example, they can mean: M' - nickel, M'' - manganese. In this case, the active material is lithium-nickel-manganese oxide (LiNiMnO ₄ ). The mole fractions of both metals M' and M'' may vary. For example, lithium-nickel-manganese oxide may have the composition: LiNi _0.5 Mn _1.5 O ₄ .

According to another preferred development of the battery cell according to the invention, the positive electrode contains as active material at least one active material in the form of a convertible compound. During absorption of an active metal, such as lithium or sodium, the convertible compounds participate in a solid-state redox reaction, during which the crystal structure of the material changes. This is accompanied by the destruction and recombination of chemical bonds. Completely reversible reactions of convertible compounds can be written, for example, as follows:

type A: MXz ↔ +y Li M+z Li _(y/z) X

type B: X ↔ +y Li Li _y X.

Examples of convertible compounds are: FeF ₂ , FeF _β , CoF ₂ , CuF ₂ , NiF ₂ , BiF ₃ , FeCl ₃ , FeCl ₂ , CoCl ₂ , NiCl ₂ , CuCl ₂ , AgCl, LiCl, S, Li ₂ S, Se, Li ₂ Se, Te, I and Lil.

According to a preferred development of the battery cell according to the invention, the compound has the composition Li _x M' _y M'' ¹ _z1 M'' ² _z2 O ₄ , where M'' ² is phosphorus, z2 is 1. The compound has the composition Li _x M' _y M'' ¹ _z1 M'' ² _z2 O ₄ are lithium metal phosphates. In particular, this compound has the composition Li _x Fe _y Mn _z P _z2 O ₄ . Examples of lithium metal phosphates are lithium iron phosphate (LiFePO ₄ ) or lithium iron manganese phosphates (Li(Fe _y Mn _z )PO ₄ ). An example of lithium-iron-manganese phosphate is Li(Fe _0.3 Mn _0.7 )PO ₄ phosphate. Also, lithium metal phosphates of other compositions are applicable in the battery cell according to the invention.

According to another preferred development of the battery cell according to the invention, it is provided that the positive electrode contains at least one metal compound. This metal compound is selected from the group consisting of a metal oxide, a metal halide or a metal phosphate. Preferably, the metal of this compound is a transition metal with an atomic number of 22 to 28 of the Periodic Table of the Elements, in particular cobalt, nickel, manganese or iron.

According to another preferred development of the battery cell according to the invention, it is provided that the positive electrode contains at least one metal compound having the chemical structure of a spinel, a layered oxide, a convertible compound or a polyanionic compound.

The invention also provides that the positive electrode contains as an active material at least one of the described compounds or a combination thereof. By compound combination is meant a positive electrode containing at least two of the described materials.

According to a preferred development of the battery cell according to the invention, it is provided that the positive electrode comprises a discharge cell. This means that in addition to the active material, the positive electrode also contains a discharge element. This discharge element is designed to be able to provide the necessary electron-conducting connection of the active material of the positive electrode. To do this, the discharge element is in contact with the active material involved in the reaction at the positive electrode.

This bit element is made flat in the form of a thin metal sheet or thin metal foil. Preferably, the thin metal foil has a perforated or mesh structure. The flat discharge element may also consist of a metal-coated polymer film. Such metallic coatings have a thickness in the range of 0.1 to 20 µm. The positive electrode active material is preferably deposited on the surface of a thin metal sheet, a thin metal foil or a metal-coated polymer film. The application of the active material can be carried out on the front and/or back side of the flat discharge element. Such flat discharge elements have a thickness in the range from 5 to 50 μm. Preferably, the thickness of the flat discharge element is 10 to 30 µm. When using flat discharge elements, the total thickness of the positive electrode can be at least 20 µm, preferably at least 40 µm, particularly preferably at least 60 µm. The maximum thickness is at most 200 µm, preferably at most 150 µm, particularly preferably at most 100 µm. The surface-specific capacitance of the positive electrode, referred to the coating on one side, is preferably at least 0.5 mA.h/cm ² when using a flat discharge element, with the following values being preferred in this order: 1 mA.h/ cm ² , 3 mAh / cm ² , 5 mAh / cm ² , 10 mAh / cm ² , 15 mAh / cm ² , 20 mAh / cm ² .

In addition, there is the possibility that the positive electrode discharge element can be made three-dimensional in the form of a porous metal structure, in particular in the form of a metal foam. The three-dimensional porous metal structure is so porous that the positive electrode active material can be embedded in the pores of the metal structure. The amount of active material incorporated or deposited determines the charge on the positive electrode. If the discharge element is made three-dimensional in the form of a porous metal structure, in particular in the form of a metal foam, then the thickness of the positive electrode is preferably at least 0.2 mm, preferably at least 0.3 mm, preferably at least at least 0.4 mm, preferably at least 0.5 mm, particularly preferably at least 0.6 mm.

According to another preferred embodiment, it is provided that the surface specific capacity of the positive electrode, when using a three-dimensional discharge element, in particular in the form of a metal foam, is preferably at least 2.5 mA.h/cm ² , and in this sequence, we prefer the following indicators: 5 mAh / cm ² , 15 mAh / cm ² , 25 mAh / cm ² , 35 mAh / cm ² , 45 mAh / cm ² , 55 mAh / cm ² , 65 mAh/cm ² , 75 mAh/cm ² . If the discharge element is made three-dimensional in the form of a porous metal structure, in particular in the form of a metal foam, then the amount of positive electrode active material, i.e. the charge of the electrode, in relation to its surface, is at least 10 mg/cm ² , preferably at least 20 mg/cm ² , preferably at least 40 mg/cm ² , preferably at least , 60 mg/cm ² , preferably at least 80 mg/cm ² , particularly preferably at least 100 mg/cm ² . Such a charge of the positive electrode favorably affects the process of charging and discharging the battery cell.

According to another development of the battery cell according to the invention, the positive electrode contains at least one binder. This binder is preferably a fluorinated binder, in particular polyvinylidene fluoride and/or a terpolymer consisting of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride. However, a binder is also possible, consisting of a single polymer formed by monomeric structural units of a conjugated carboxylic acid, or an alkali metal salt, an alkaline earth metal salt, or an ammonium salt of a conjugated carboxylic acid, or a combination thereof. Also, the binder may consist of a polymer based on monomeric structural units of styrene and butadiene. In addition, the binder may come from the group of carboxymethyl celluloses. The binder is present in the positive electrode mainly at a concentration of not more than 20 wt. %, preferably not more than 15 wt.%, preferably not more than 10 wt.%, preferably not more than 7 wt.%, preferably not more than 5 wt.%, particularly preferably not more than 2 wt.%, based on the total weight of the positive electrode. The structure of the battery cell.

Below are the preferred developments of the battery cell according to the invention in relation to its structure.

To further improve the function of the battery cell, another preferred development of the battery cell according to the invention provides that the cell contains a plurality of negative and a plurality of positive electrodes which are alternately stacked within a housing. In this case, the positive and negative electrodes are electrically separated from each other by separators.

The separator may be comprised of a nonwoven material, a membrane, a woven material, a knitted material, an organic material, an inorganic material, or a combination thereof. Organic separators can be made from unsubstituted polyolefins (for example, polypropylene or polyethylene), partially or completely halogenated polyolefins (for example, partially or completely fluorine-substituted, in particular polyvinylidene fluoride (PVDF), ethylenetetrafluoroethylene (ETFE), polytetrafluoroethylene (PTFE)), polyesters , polyamides or polysulfones. Separators containing a combination of organic and inorganic materials are, for example, textile materials made of glass fibers, in which the glass fibers have a corresponding polymer coating. The coating preferably contains a fluorine-containing polymer, such as polytetrafluoroethylene (PTFE), ethylenetetrafluoroethylene (ETFE), perfluoroethylene-propylene (FEP), a terpolymer of tetrafluoroethylene, hexafluoroethylene and vinylidene fluoride (THF), perfluoroalkoxypolymer (PFA), aminosilane, polypropylene or polyethylene (PE) . The separator may be folded into the battery cell housing, for example in a so-called ''Z-fold''. With such a Z-fold, the strip separator is folded in a Z-shape through or around the electrodes. Also, the separator can be made in the form of separating paper.

Within the framework of the invention, the separator can be made in the form of a shell, while each positive and negative electrode is covered with it. The shell may consist of a nonwoven material, a membrane, a fabric, a knitted fabric, an organic material, an inorganic material, or a combination thereof.

The positive electrode sheath ensures uniform movement and distribution of ions in the battery cell. The more uniform the distribution of ions, in particular in the negative electrode, the greater the possible charging of the negative electrode with the active material and hence the useful capacity of the battery cell. At the same time, the risks that may be associated with uneven charging and the resulting precipitation of the active metal are eliminated. These advantages are achieved primarily when the positive electrodes of the battery cell are covered by a sheath.

The dimensions of the surface of the electrodes and the shell can be coordinated with each other so that the outer dimensions of the shell and the outer dimensions of the uncovered electrodes coincide, at least in one dimension.

The surface area of the sheath may preferably be larger than the surface area of the electrode. In this case, the shell extends beyond the electrode. Therefore, both covering the electrode on both sides of the sheath layer can be connected to each other along the edge of the positive electrode by an edge bond.

According to another preferred embodiment of the battery cell according to the invention, the negative electrodes are sheathed, while the positive electrodes are not.

Other optimal features of the invention are described and explained in more detail below with reference to the drawings, examples and experiments:

fig. 1 shows a first example of a battery cell according to the invention in cross section;

fig. 2 shows an electron microscope image of a three-dimensional pore structure of a metal foam according to the first embodiment in FIG. 1 as a detailed view;

fig. 3 shows a second example of a battery cell according to the invention in cross section;

fig. 4 shows a detail of the second embodiment in FIG. 3;

fig. 5 shows a third exemplary embodiment of a battery cell according to the invention, exploded;

fig. 6 shows a curve of potential (in Volts) during two charge/discharge cycles as a function of the percent charge of a test whole battery cell with lithium metal as the negative electrode active material, with a charge and discharge current of 0.1 mA/cm ² ;

fig. 7 shows the curve of the potential (in Volts) during two charge/discharge cycles as a function of the percentage charge of the tested whole battery cell with lithium metal as the active material of the negative electrode, with an initialization cycle being carried out before both charge/discharge cycles, the charge current / discharge was 0.1 mA/cm ² ;

fig. 8 shows the curve of the potential (in Volts) during two charge/discharge cycles as a function of the percentage charge of the tested whole battery cell with lithium metal as the negative electrode active material, with external pressure applied to the battery cell, prior to both charge cycles / discharging, an initializing cycle was performed, the charging/discharging current was 0.1 mA/cm ² ;

fig. 9 shows the negative electrode obtained after disassembling the second test whole battery cell in Experiment 1;

fig. 10 shows the curve of the potential (in Volts) during two charge/discharge cycles as a function of the percentage charge of the tested whole battery cell with lithium metal as the active material of the negative electrode, with an initialization cycle being carried out before both charge/discharge cycles, the charge current / discharge was 0.5 mA/cm ² ;

fig. 11 shows the curve of the potential (in Volts) during two charge/discharge cycles as a function of the percentage charge of the tested whole battery cell with lithium metal as the active material of the negative electrode, with an initialization cycle being carried out before both charge/discharge cycles, the charge current / discharge was 1.0 mA/cm ² ;

fig. 12 shows the cycle efficiency in % as a function of the number of cycles carried out with the test whole battery cell with lithium metal as the negative electrode active material, while the charge/discharge current was 1.0 mA/cm ² ;

fig. 13 shows the cycle efficiency in % as a function of the number of cycles conducted with three test whole battery cells with lithium metal as the negative electrode active material, two test whole battery cells containing electrolyte 1, one tested whole battery cell containing the control electrolyte;

fig. 14 shows the electrical conductivity in mS/cm of electrolyte 1 as a function of the concentration of compound 1;

fig. 15 shows the electrical conductivity in mS/cm of electrolyte 3 as a function of the concentration of compound 3;

fig. 16 shows the electrical conductivity in mS/cm of electrolyte 4 as a function of the concentration of compound 4.

In FIG. 1 shows a first example of a battery cell 2 according to the invention in cross section. The battery cell 2 is made in the form of a prismatic figure and includes, among other things, a housing 1. This housing 1 covers the electrode device 3, consisting of three positive electrodes 4 and four negative electrodes 5. The positive 4 and negative 5 electrodes are located in the electrode device 3 in the form stacks, alternating in it. However, the housing 1 can accommodate more positive electrodes 4 and/or negative electrodes 5. In general, it is preferable that the number of negative electrodes 5 be one more than the number of positive electrodes 4. This is due to the fact that the outer end surfaces of the electrode stack are formed by the surfaces of the negative electrodes 5. The electrodes 4, 5 are connected through their terminals 6, 7 to the corresponding connecting contacts 9, 10 of the battery cell 2. The cell 2 is filled with an electrolyte based on SO ₂ in such a way that the electrolyte penetrates as completely as possible into all pores or voids, in particular into the electrodes 4, 5. FIG. 1 electrolyte is not shown. In this exemplary embodiment, the positive electrodes 4 contain an intercalary compound as an active material. This intercalary compound is LiCoMnO ₄ with a spinel structure.

In this exemplary embodiment, the electrodes 4, 5 are flat, i. in the form of layers with a thickness that is negligible compared to their surface extent. Accordingly, they are separated from each other by separators 11. The housing 1 of the battery cell 2 is made essentially rectangular in shape, and the electrodes 4, 5 and the walls of the housing 1 shown in section are located perpendicular to the plane of the drawing and are predominantly straight and even. However, the battery cell 2 can also be coiled, in which the electrodes consist of thin layers that are wound together with a separator material. Separators 11, firstly, separate the positive 4 and negative 5 electrodes spatially and electrically and, secondly, are permeable, among other things, to active metal ions. In this way, large electrochemically active surfaces are created, which provide a correspondingly large current output.

In addition, the electrodes 4, 5 have a discharge element designed to provide electronic conductivity of the connection of the active material of the corresponding electrode. This bit element is in contact with the active material involved in the reaction on the corresponding electrode 4, 5 (not shown in Fig. 1). The discharge element is made in the form of a porous metal foam 18. The metal foam 18 is located along the thickness of the electrodes 4, 5. The active material of the positive electrodes 4 and negative electrodes 5 penetrates into the pores of this metal foam 18, uniformly filling its pores throughout the thickness of the metal structure. To increase the mechanical strength, the positive electrodes 4 contain a binder. By this binder is meant a fluoropolymer. The negative electrodes 5 contain lithium as an active material.

In FIG. 2 is an electron microscope image of the 3D porous structure of the metal foam 18 of the first embodiment in FIG. 1. Using the indicated scale, it can be determined that the pore diameter P is on average over 100 µm, i.e. is relatively large. This metal foam refers to nickel metal foam.

In FIG. 3 shows a second example of a battery cell 20 according to the invention in cross section. This second embodiment differs from the first in FIG. 1 by the fact that the electrode device contains one positive electrode 23 and two negative electrodes 22. Accordingly, they are separated from each other by separators 21 and closed by a housing 28. The positive electrode 23 contains a discharge element 26 in the form of a flat metal foil, on which an active material is deposited on both sides 24 of the positive electrode 23. The negative electrodes 22 also have a discharge element 27 in the form of a flat metal foil, on which the active material 25 of the negative electrode 22 is deposited on both sides. electrodes closing the electrode stack can only have one-sided coating with active material. The uncoated side faces the housing wall. The electrodes 22, 23 are connected through their terminals 29, 30 to the corresponding connecting contacts 31, 32 of the battery cell 20.

In FIG. 4 shows a flat metal foil which is used as the discharge element 26, 27 for positive electrodes 23 and negative electrodes 22 in the second embodiment of FIG. 3. This metal foil has a hole or mesh structure and a thickness of 20 microns.

In FIG. 5 shows a third exemplary embodiment of a battery cell 40 according to the invention, exploded. This third embodiment differs from the two previously discussed embodiments in that the positive electrode 44 is covered by sheath 13. In this case, the surface extent of sheath 13 exceeds the surface extent of positive electrode 44, the boundary 14 of which in FIG. 5 is shown with a dotted line. Two layers 15, 16 of the shell 13 covering both sides of the positive electrode 44 are connected to each other at the reverse edge of the positive electrode 44 by an edge connection 17. Both negative electrodes 45 are not covered by the shell. The electrodes 44 and 45 can make contact through their leads 46, 47.

Example 1: Preparation of control electrolyte.

Used in the examples described below, the control electrolyte was prepared by the method disclosed in the description of the invention to the patent EP 2 954 588 B1 (below V3). First, lithium chloride (LiCl) was dried in vacuum at 120°C for three days. Aluminum particles (AI) were dried in vacuum for two days at 450°C. LiCl, aluminum chloride (AlCl ₃ ) and AI were mixed together in a molar ratio of AlCl ₃ : LiCl : AI=1 : 1.06 : 0.35 in a glass vessel with a gas outlet. This mixture was then gradually thermally treated until a salt melt was obtained. After cooling, the formed salt melt was filtered, cooled to room temperature, and SO ₂ was added to achieve the required molar ratio between SO ₂ and LiAlCl ₄ . The reference electrolyte thus obtained had the composition LiAlCl ₄ *×SO ₂ , with x depending on the amount of SO ₂ supplied.

Example 2 Preparation of an SO ₂ electrolyte for a battery cell in four embodiments 1, 2, 3 and 4.

For the experiments described below, in four exemplary embodiments 1, 2, 3 and 4, electrolytes based on SO ₂ were prepared (hereinafter referred to as electrolytes 1, 2, 3 and 4). First, four different first conductive salts were prepared for this according to the formula (1) using the method described in the following sources of information [V4], [V5] and [V6]:

[V4] „I. Crossing, Chem. Eur. J. 2001, 7, 490;

[V5] SEE. Ivanova et al., Chem. Eur. J. 2001, 7, 503;

[V6] Tsujioka et al., J. Electrochem. Soc, 2004, 151, A1418''

These four different first conductive salts of formula (1) are referred to below as compounds 1, 2, 3 and 4. They come from the group of polyfluoroalkoxyaluminates and are prepared according to the following reaction equation based on LiAlH4 and the corresponding alcohol R-OH in hexane, where

R ¹ \u003d R ² \u003d R ³ \u003d R ⁴ .

As a result, the following compounds 1, 2, 3, 4 were formed with the total and structural formulas:

To purify compounds 1, 2, 3, 4, they were first subjected to recrystallization. As a result, the remainder of the LiAlH ₄ reagent was removed from the first conductive salt, since this reagent is likely to be able to generate a spark when interacting with possibly present traces of water in SO ₂ . This was followed by the dissolution of compounds 1, 2, 3, 4 in SO ₂ . It was noted that compounds 1, 2, 3, 4 are well soluble in SO ₂ . The preparation of electrolytes 1, 2, 3 and 4 was carried out at low temperature or under pressure in accordance with the following technological operations 1 - 4:

1) placing the corresponding connection 1, 2, 3, 4 in a pressure flask with a riser,

2) evacuation of the pressure flask,

3) liquid SO ₂ inlet,

4) repeat operations 2+3 until the target amount of SO ₂ is introduced. The concentration of compounds 1, 2, 3, 4 in electrolytes 1, 2, 3, 4 was 0.6 mol/l (amount of substance per 1 liter of electrolyte), unless otherwise indicated in the description of the experiment. Using electrolytes 1, 2, 3, 4 and the control electrolyte, the experiments described below were carried out.

Example 3: Manufacture of tested whole battery cells.

The whole battery cells used in the experiments described below were battery cells with two negative electrodes and one positive electrode, which were separated by a separator. The positive electrodes contained an active material, a conduction activator and a binder. The active material of the positive electrode is specified in the description of the corresponding experiment. The negative electrodes contained as active material lithium metal deposited or already present on the negative electrode discharge element. The discharge element of the positive and negative electrodes consisted of nickel. The tested whole cells of the storage battery were filled with electrolytes necessary for the experiments, i.e. either control electrolyte or electrolytes 1, 2, 3 or 4.

Several experiments were made for each experiment, i.e. 2 to 4 identical test whole battery cells. The results obtained during the experiments are respectively averaged on the basis of measured values for identical tested whole cells of the battery.

Example 4. Measurements of the tested whole cells of the battery.

Coating capacity.

The capacity consumed in the first cycle for the formation of a coating layer on the negative electrode is an important criterion for the quality of a battery cell. Such a coating layer is formed when the tested whole battery cell is first charged at the negative electrode. In this formation of the coating layer, lithium ions are irreplaceably consumed (capacity of the coating layer), as a result of which the tested whole battery cell has a smaller capacity participating in the cycle in subsequent cycles. The capacitance of the coating layer as a percentage of the theoretical one, spent on the formation of the coating layer on the negative electrode, was calculated using the following formula:

coating layer capacity (% of theory)=(Q _Iad (x mAh) - Q (y mAh) / Q _NEL .

Q _NEL means the given amount of charge in mAh in the corresponding experiment; Q _ent describes the amount of charge, in mAh, that was obtained when the whole battery cell under test was subsequently discharged. Q _NEL means the theoretical capacitance of the applied negative electrode. The theoretical capacity is, for example, in the case of graphite 372 mAh/g.

The nominal capacitance is determined by subtracting the capacitance of the coating layer from the theoretical capacitance of the positive electrode (=Q _Iad (x mAh)). discharge capacity.

When measuring in the tested whole cells of the battery, for example, the discharge capacity was determined through the number of cycles. To do this, the tested whole cells of the battery were charged at a certain strength of the charging current until a certain upper potential was reached. The corresponding certain upper potential was maintained for such a long time until the charging current decreased to a certain value. Then the discharge was carried out at a certain strength of the discharge current until a certain discharge potential was reached. With this charging method, we are talking about I/U (current / voltage) charging. Depending on the required number of cycles, this process may be repeated.

The upper potentials or discharge potential and the corresponding current during charging or discharging are indicated in the description of the experiments. The indicator to which the charging current should decrease is also indicated in the description of the experiments.

The concept of "upper potential" is used as a synonym for the concepts of "charging potential", "charging voltage", "final charging voltage" and "upper potential limit". These terms refer to the voltage/potential to which a battery cell or battery is charged using a charger.

Preferably, the battery is charged at a C/2 current rate and a temperature of 22°C. At a charging or discharging rate of 1C, the nominal capacity of a battery cell is, by definition, charged or discharged in one hour. Accordingly, the charging rate C/2 means a charging time of 2 hours.

The concept of "discharge potential" is synonymous with the concept of "low battery cell voltage". This indicates the voltage/potential to which the cell or battery is discharged by the charger. Preferably, the battery is discharged at a C/2 current rate and a temperature of 22°C.

The discharge capacity is derived from the discharge current and the time required to fulfill the end of discharge criteria. The corresponding figures show the average discharge capacity as a function of the number of cycles. These average discharge capacities are expressed as % of nominal capacity.

The ratio between the discharge capacity Q _ent and the charging capacity Q _iad conveys the efficiency of the cycle: Z=Q _ent /Q _iad . The charging capacity is set via the charging parameters. The discharge capacity, as described above, is determined for each cycle.

Experiment 1. Carrying out cycles with the tested whole cells of the battery using charging and discharging current of 0.1 mA/cm ² .

Using lithium metal as the active material of the negative electrode, three different experiments were carried out with the tested whole cells of the battery according to example 3. Three tested whole cells of the battery were filled with the electrolyte 1 described in example 2. The positive electrodes contained lithium nickel oxide as an active material. manganese-cobalt. Two charge/discharge cycles were carried out and the discharge capacity was determined. With the first tested whole battery cell, two charge/discharge cycles were carried out directly. With the second tested whole cell of the battery, an initialization cycle was performed before carrying out two charge/discharge cycles. In this case, lithium metal was precipitated for 3 min. current 12 mA and then until the end of charging using 0.1 mA/cm ² . Then came the discharge. After that, two cycles of charging / discharging began. With the help of the third tested whole battery cell, the effect of external pressure was investigated. To do this, the housing of the whole battery cell under test was pressed in a certain way from the outside under a pressure of approx. 50 N/cm2 ^. An initialization cycle was then carried out as described for the second test whole battery cell, followed by two charge/discharge cycles.

The whole cells of the battery under test were charged using a current of 0.1 mA/cm ² until an upper potential of 4.4 V and a charging capacity of 8 mAh/cm ² were reached. Then, discharge was carried out with a current of 0.1 mA/cm2 until a potential ^of 2.9 V was reached.

Figures 6, 7 and 8 show, respectively, the potential in Volts of three test whole battery cells during charging and discharging as a function of charge in %, correlated with the maximum charge. Also in the figures, one can see for each tested whole battery cell the efficiency of the depicted two cycles.

All three tested whole battery cells had a similar potential curve in cycle 1 and in cycle 2. The cycle efficiency was over 90% for all tested whole battery cells, and it is somewhat better in the tested whole battery cells with which the initialization cycle was carried out.

Experiment 2. Morphology of lithium deposition.

To determine the morphology of the deposited lithium metal, the second test whole battery cell was disassembled after several cycles in Experiment 1. FIG. 9 shows this negative electrode, on which one can see a uniform and compact deposition of lithium. No selective deposition of lithium was noted, since the entire electrode had a uniform coating. This optimal lithium deposition indicates good cycle stability of lithium in the electrolyte 1 used.

Experiment 3. Carrying out cycles with the tested whole cells of the battery using a charge/discharge current of 0.5 and 1.0 mA/cm ² .

To study the processes of charging and discharging with increased currents, two additional tested whole cells of the battery were made, as described in experiment 1. Using the first of them, two cycles of charging and discharging with a charging and discharging current of 0.5 mA/cm ² were carried out. During the application of the second test whole battery cell, the charging/discharging current was 1.0 mA/cm ² . This element was charged and discharged 21 times. For both tested whole cells of the battery, an initialization cycle was carried out before the charge/discharge cycles. Charging of the tested entire cells of the battery was carried out with a current of 0.5 mA/cm ² and 1.0 mA/cm ² until a potential of 4.4 V and a charging capacity of 8 mAh/cm ² were reached. This was followed by discharge with a current of 0.5 and 1.0 mA/cm2 until a potential ^of 2.9 V was reached.

In Figures 10 and 11 one can see, respectively, the potential in Volts of the two tested whole cells of the battery during charging and discharging, as a function of charge in %, correlated with the maximum charge. The same figures also show, for each single battery cell tested, the performance of the two depicted cycles. Both tested whole battery cells showed a similar potential curve in cycle 1 and cycle 2. The cycle efficiency of both tested whole battery cells was over 97% and was somewhat higher in the tested whole battery cell, for which a current of 1 mA/cm ² was applied. . Using this test whole battery cell (1 mA/cm ² ), subsequent cycles were carried out. In FIG. 12 shows the cycle efficiency in % as a function of the number of cycles. Cycle efficiency shows a steady curve and at cycle 21 was still approx. 95%.

Experiment 4. Cycle efficiency of tested whole battery cells with electrolyte 1 compared to tested whole battery cells with control electrolyte.

To compare the cycle efficiency of the tested whole battery cells with electrolyte 1 with the same efficiency of the tested whole battery cell with the reference electrolyte, the test whole cells with the reference electrolyte were first made. The whole battery cells tested contained lithium iron phosphate as the positive electrode active material and lithium metal as the negative electrode active material. The tested whole battery cell contained a control electrolyte of composition LiAICl ₄ ×6SO ₂ .

To prevent corrosion of lithium, i.e. losses of lithium participating in the cycles in this electrolyte, a current of 7.5 mAh/cm ² was chosen for fast charging and discharging. With this current, the test whole cells of the battery were charged to a potential of 3.6 V and then discharged to a potential of 2.5 V. For comparison, the second test whole cell of the battery from experiment 1 was used (charging/discharging current 0.1 mA/cm ² ) and the second test subject whole battery cell from experiment 3 (charging/discharging current 1 mA/cm ² ), both had electrolyte 1.

In FIG. 13 shows the cycle efficiency in %, as a function of the number of cycles, of the first four charge/discharge cycles of the whole battery cell under test using a charge/discharge current of 0.1 mA/cm2, ^the first seven charge/discharge cycles of the whole battery cell under test with the charging current. /discharge 1 mA/cm ² and the first seven cycles of charge/discharge of the tested whole battery cell with a control electrolyte. The cycle efficiency of the tested whole battery cells with electrolyte 1 showed a very stable curve. After four cycles, the first tested battery cell achieved a cycle efficiency of 98%, the second tested battery cell reached a cycle efficiency of 92% after seven cycles. The tested whole battery cell with control electrolyte showed a significantly worse result. He achieved on the 7th cycle an efficiency equal to only about 68%.

Experiment 5. Determination of the electrical conductivity of electrolytes 1, 3 and 4.

To determine the electrical conductivity, electrolytes 1, 3, and 4 were prepared with different concentrations of compounds 1, 3, and 4. For each concentration of different compounds, the electrical conductivity of the electrolytes was determined using the conductive measurement method. At the same time, after temperature control, the two-electrode sensor was kept in contact with the electrolyte solution and measurements were made in the range of 0–50 mS/cm. During measurements, care was taken to ensure that the sensor could react with the electrolyte solution containing SO ₂ .

In FIG. 14 shows the electrical conductivity of electrolyte 1 as a function of the concentration of compound 1. The maximum electrical conductivity is noted at a concentration of compound 1 from 0.6 to 0.7 mol/l, which was about 37.9 mS/cm. In comparison, prior art organic electrolytes such as LP30 (1 M LJPF6 / EC-EMC (1:1 by weight) showed an electrical conductivity of only about 10 mS/cm.

Figures 15 (electrolyte 3) and 16 (electrolyte 4) show the electrical conductivity of electrolytes 3 and 4 obtained at different concentrations. When using electrolyte 4, no more than 18 mS/cm was achieved at a conductive salt concentration of 1 mol/l. Electrolyte 3 showed its maximum electrical conductivity of 0.5 mS/cm at a conductive salt concentration of 0.6 mol/l. And although electrolyte 3 showed a lower electrical conductivity, charging and discharging the tested whole battery cell, as follows from experiment 4, is quite possible.

Claims (65)

1. Battery cell (2, 20, 40) containing active metal, at least one positive electrode (4, 23, 44) with discharge cell (26), at least one negative electrode (5, 22, 45) with discharge element (27), housing (1, 28) and electrolyte, wherein the negative electrode (5, 22, 45) contains, at least in the charged state of the battery cell, lithium metal as an active material, the electrolyte is based on SO ₂ and contains at least one first conductive salt corresponding to the formula (1)

where - Μ means a metal selected from the group consisting of alkali metals, alkaline earth metals, zinc and aluminum; - x integer from 1 to 3; - substituents R ¹ , R ² , R ³ and R ⁴ are selected independently of each other from the group consisting of C ₁ -C ₁₀ alkyl, C ₂ -C ₁₀ alkenyl, C ₂ -C ₁₀ alkynyl, C ₃ -C ₁₀ cycloalkyl , C ₆ -C ₁₄ aryl and C ₅ -C ₁₄ heteroaryl, - Z aluminum or boron. 2. Battery cell (2, 20, 40) according to claim 1, wherein lithium metal is deposited during charging of the battery cell on the discharge cell (27) of the negative electrode (5, 22, 45). 3. The battery cell (2, 20, 40) according to claim 1 or 2, wherein the lithium metal in the charged state of the battery cell is located on the discharge cell (27) of the negative electrode (5, 22, 45). 4. Element (2, 20, 40) battery according to any one of paragraphs. 1-3, in which the lithium metal is on the discharge cell (27) of the negative electrode (5, 22, 45) even before the first charge of the battery cell. 5. Battery cell (2, 20, 40) according to any one of the previous paragraphs, in which the bit element (27) of the negative electrode (5, 22, 45) is made: - either flat in the form of a metal sheet or metal foil, - or three-dimensional in the form of a porous metal structure, in particular metal foam (18). 6. The battery cell (2, 20, 40) according to any one of the preceding claims, wherein the discharge cell (27) of the negative electrode (5, 22, 45) is made at least partially of a lithium storage material selected from the group consisting of: - carbon, in particular in the form of graphite, - a material that forms an alloy with lithium, - a carbon-free lithium intercalary material, in particular lithium titanate (eg Li ₄ Ti ₅ O ₁₂ ), - conversion material, in particular transition metal oxide. 7. Cell (2, 20, 40) of the battery according to claim 6, in which the material that forms an alloy with lithium is selected from: - a group consisting of lithium storage metals and metal alloys, mainly from Si, Ge, Sn, SnCo _x C _y , SnSi _x , or - a group consisting of oxides of lithium-accumulating metals and metal alloys, mainly SnO _x , SiO _x , oxide glasses Sn and Si. 8. Battery cell (2, 20, 40) according to any one of the preceding claims, wherein the positive electrode (4, 23, 44) contains as active material at least one compound having preferably the composition: Li _x M' _y M '' _z O _a , in which: - M' means at least one metal selected from the group consisting of the elements Ti, V, Cr, Mn, Fe, Co, Ni, Cu, Zn, - Μ'' means at least one element selected from the group consisting of elements of groups 4, 5, 6, 7, 8, 9, 10, 11, 12, 13, 14, 15 and 16 of the Periodic Table of the Elements; - x, y independently from each other numbers greater than 0; - z is a number greater than or equal to 0, - a is a number greater than 0. 9. Cell (2, 20, 40) of the battery according to claim 8, in which the compound has the composition Li _x M' _y M'' _z O _a , where mean: M' - manganese, M'' - cobalt, while preferably x, y, z are equal to 1 and equal to 4. 10. Battery cell (2, 20, 40) according to claim 8 or 9, in which the compound has the composition LixM' _y M''zOa, where M' is nickel and manganese, M'' is cobalt, and has formula Li _x Ni _y iMn _y 2CozOa. 11. The cell (2, 20, 40) of the battery according to claim 8, in which the compound has the composition Li _x M' _y M'' ¹ _z1 M'' ² _z2 O ₄ where M'' ² means phosphorus, z2 is 1. 12. Battery cell (2, 20, 40) according to claim 11, in which the compound has the composition Li _x M' _y M'' ¹ _z1 PO ₄ , where M' is iron, M'' ¹ is manganese, wherein the compound preferably has the composition Li(Fe _0.3 Mn _0.7 )PO ₄ . 13. Cell (2, 20, 40) of the battery according to any of the previous paragraphs, in which the substituents R ¹ , R ² , R ³ , R ^{4 of} the first conductive salt are selected independently from each other from the group consisting of: - C ₁ -C ₆ alkyl, preferably C ₂ -C ₄ alkyl, particularly preferably the alkyl groups 2-propyl, methyl and ethyl; - C ₂ -C ₆ alkenyl, preferably C ₂ -C ₄ alkenyl, particularly preferably ethenyl and propenyl alkenyl groups; - C ₂ -C ₆ alkynyl, preferably C ₂ -C ₄ alkynyl; - C ₅ -C ₇ cycloalkyl; - phenyl; - C ₅ -C ₇ heteroaryl. 14. Cell (2, 20, 40) of the battery according to any one of the previous paragraphs, in which at least one of the substituents R ¹ , R ² , R ³ , R ^{4 of} the first conductive salt is replaced by at least one fluorine atom and /or at least one chemical group, wherein the chemical group is selected from the group consisting of C ₁ -C ₄ alkyl, C ₂ -C ₄ alkenyl, C ₂ -C ₄ alkynyl, phenyl and benzyl. 15. The battery cell (2, 20, 40) according to any one of the preceding claims, wherein at least one of the substituents R ¹ , R ² , R ³ , R ^{4 of} the first conductive salt is a CF ₃ group or an OSO ₂ CF ₃ group . 16. Battery cell (2, 20, 40) according to any one of the preceding claims, wherein the first conductive salt is selected from the group consisting of

17. Battery cell (2, 20, 40) according to any one of the preceding claims, wherein the electrolyte contains at least one second conductive salt different from the first conductive salt of formula (1). 18. Battery cell (2, 20, 40) according to claim 17, wherein the second conductive electrolyte salt is an alkali metal compound, in particular a lithium compound, selected from the group consisting of aluminate, halide, oxalate, borate, phosphate, arsenate and gallate. 19. Battery cell (2, 20, 40) according to claim 17 or 18, wherein the second conductive electrolyte salt is lithium tetrahaloaluminate, in particular lithium tetrachloroaluminate. 20. Battery cell (2, 20, 40) according to any one of the preceding claims, wherein the electrolyte contains at least one additive. 21. Battery cell (2, 20, 40) according to claim 20, wherein the electrolyte additive is selected from the group consisting of vinylene carbonate and its derivatives, vinylethylene carbonate and its derivatives, methylethylene carbonate and its derivatives, lithium (bis-oxylate) borate , lithium difluoro(oxalate)borate, lithium tetrafluoro(oxalate)phosphate, lithium oxalate, 2-vinylpyridine, 4-vinylpyridine, cyclic exomethylene carbonates, sultones, cyclic and acyclic sulfonates, acyclic sulfites, cyclic and acyclic sulfinates, organic esters of inorganic acids, acyclic and cyclic alkanes, which (acyclic and cyclic alkanes) have a boiling point at a pressure of 1 atm, at least 36°C, aromatic compounds, halogenated cyclic and acyclic sulfonylimides, halogenated cyclic and acyclic phosphate esters, halogenated cyclic and acyclic phosphines, halogenated cyclic and acyclic phosphites, halogen halogenated cyclic and acyclic phosphazenes, halogenated cyclic and acyclic silylamines, halogenated cyclic and acyclic esters, halogenated cyclic and acyclic amides, halogenated cyclic and acyclic anhydrides, and halogenated organic heterocycles. 22. Battery cell (2, 20, 40) according to any of the preceding claims, wherein the electrolyte has the following composition, related to the total weight of the electrolyte: (i) 5-99.4 wt. % sulfur dioxide, (ii) 0.6-95 wt. % first conductive salt, (iii) 0-25 wt. % second conductive salt, (iv) 0-10 wt. % additive. 23. Cell (2, 20, 40) of the battery according to any of the previous paragraphs, in which the concentration of the first conductive salt is from 0.01 to 10 mol/l, preferably from 0.05 to 10 mol/l, preferably from 0, 1 to 6 mol/l, particularly preferably 0.2 to 3.5 mol/l, based on the total electrolyte volume. 24. Battery cell (2, 20, 40) according to any one of the preceding paragraphs, wherein the electrolyte contains at least 0.1 mol SO ₂ , preferably at least 1 mol SO ₂ , preferably at least 5 mol SO ₂ , preferably at least 10 mol SO ₂ , particularly preferably at least 20 mol SO ₂ , per 1 mol of conductive salt. 25. Battery cell (2, 20, 40) according to any of the preceding claims, wherein the positive electrode (4, 23, 44) contains at least one metal compound selected from the group consisting of a metalloid, a metal halide, and a metal phosphate , wherein the metal of the compound is preferably a transition metal of serial number 22-28 of the Periodic Table of the Elements, in particular cobalt, nickel, manganese or iron. 26. The battery cell (2, 20, 40) according to any one of the preceding claims, wherein the positive electrode (4, 23, 44) contains at least one metal compound having the chemical structure of a spinel, a layered oxide capable of converting a compound, or polyanionic compound. 27. Battery cell (2, 20, 40) according to any one of the previous paragraphs, in which the positive electrode (4, 23, 44) contains a discharge cell (34), preferably made: - either flat in the form of a metal sheet or metal foil, - or three-dimensional in the form of a porous metal structure, in particular metal foam (18). 28. Cell (2, 20, 40) of the battery according to any of the previous paragraphs, in which the positive electrode (4, 23, 44) and/or the negative electrode (5) contain at least one binder, preferably a fluorinated binder, in particular polyvinylidene fluoride, and/or a terpolymer consisting of tetrafluoroethylene, hexafluoropropylene and vinylidene fluoride, or a polymer binder formed by monomeric structural units of a conjugated carboxylic acid, or an alkali metal, alkaline earth metal or ammonium salt of this conjugated carboxylic acid, or a combination thereof, or a binder made of a polymer based on the monomeric structural units of styrene and butadiene, or a binder from the group of carboxymethyl celluloses, while the binder is preferably contained in an amount of not more than 20 wt. %, preferably not more than 15 wt. %, preferably not more than 10 wt. %, preferably not more than 7 wt. %, preferably not more than 5 wt. %, particularly preferably not more than 2 wt. %, based on the total weight of the positive electrode. 29. Cell (2, 20, 40) of the battery according to any of the previous paragraphs, which contains several negative electrodes (5, 22, 45) and several positive electrodes (4, 23, 44), which, intermittently, are arranged in the form stacks inside the housing (1, 28), while the positive (4, 23, 44) and negative (5, 22, 45) electrodes are preferably electrically separated from each other by separators (11, 13, 21).

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