Production method of rechargeable high-energy battery with composite cathode having anion redox activity

Abstract

The present invention relates to a method for manufacturing a rechargeable high-energy battery having a composite cathode with anion redox activity, wherein the composite cathode contains lithium hydroxide as an electrochemically active component, the lithium hydroxide is mixed and contacted with an electronically or mixed-conductive transition metal and / or transition metal oxide to form an electronically or mixed-conductive network structure, this mixture is applied to a current conductor, and the resulting composite cathode is placed together with a separator, a lithium-conductive electrolyte, and a lithium-containing anode in a battery housing to obtain an electrochemical cell, and at least one initial forming cycle is performed on the electrochemical cell.

Description

[0001] The present invention relates to a method for manufacturing a rechargeable high-energy battery having an anion redox-active composite cathode. Prior art

[0002] The operating principle of commercially available rechargeable lithium-ion batteries is based on an insertion mechanism: both the negative electrode (anode) and the positive electrode (cathode) are made of materials capable of embedding (inserting) lithium ions without fundamentally changing the microstructure. Although the anode material is a carbon-based material (graphite or hard carbon), the cathode active material consists of transition metal oxides. The transition metals in the latter oxides are redox-active, i.e., they change their oxidation state during charging or discharging. This is illustrated by the following exemplary reaction:

[0003]

[0004] For currently used cathode materials, when the battery is charged / discharged, the oxidation state of the redox-active metal centers only changes by one level. In the above case, the oxidation state changes between +III and +IV. For this reason, the capacity of the cathode material is relatively low. In the case of the conventional cathode material LiCoO 2 , the theoretical capacity is 274 mAh / g, and in practice only about 135 mAh / g of it can be used. For the limiting stoichiometry LiC 6 , the graphite material used for the anode also has a relatively low capacity of 372 mAh / g. Therefore, the theoretical energy density of the graphite (C 6 ) / LiCoO 2 system is also unsatisfactorily low, at about 380 Wh / g. Another disadvantage of lithium-ion batteries is that the cathode materials used are mainly elements with relatively low availability, such as cobalt and nickel. There are concerns that these metals cannot be obtained in sufficient quantities to ensure the full supply of lithium batteries for global electric vehicles and stationary energy storage.

[0005] As an alternative to cation redox-active cathode materials, open-cell battery systems are being investigated. These battery systems contain a porous structure that is open to the environment, mainly composed of carbon, and the surface of the carbon is coated with a noble metal-containing catalyst so that the diffused oxygen can combine to form lithium oxide (oxygen reduction reaction):

[0006] Li + +e - +O 2 →LiO 2

[0007] In the initially formed product lithium superoxide (LiO 2 ), the average oxidation number of oxygen is -0.5. Further absorption of lithium produces lithium peroxide (Li 2 O 2) The lithium oxide of the latter can be re-converted into lithium and elemental oxygen by reversing the formation reaction in the presence of a metal catalyst that catalyzes the oxidation of oxygen:

[0008] Li 2 O 2 →2Li + +2e - +O 2

[0009] The disadvantages are that the above air electrode only has a very moderate power density, and most importantly, only has a very limited reversibility. Therefore, this cathode form is still far from being used in practical applications. In addition, there is usually a large gap of 0.5 - 1 V between the charging potential and the discharging potential, making the energy efficiency ("round-trip efficiency") completely unsatisfactory. The current technical challenges mean that the commercialization of lithium / air batteries is expected to be achieved earliest within 10 - 20 years. For a review, see K. Amine et al., Chem. Reviews 2014, 5611 - 40, 114.

[0010] Also efforts have been made to use lithium oxides (Li 2 O, Li 2 O 2 and LiO 2 ) as active cathode materials that act according to the anion redox principle. Since all the lithium oxides mentioned are electron insulators, they must exist in the form of fine powder (amorphous or nanoparticles) or very thin layers, and the individual particles must be in contact with the aid of a conductive network structure. Conductive fine powder metals as well as many metal oxides and lithium metal oxides can be used for this purpose. Such systems are known in the literature, and only exemplary embodiments are mentioned here. A composite cathode composed of 20% Li 2 O 2 , 20% carbon black and 60% PEO - LiClO 4 can be discharged / charged three times in an electrochemical cell with a lithium foil as the counter electrode (M.D. Wardinsky and D.N. Bennion, Proc. Electrochem. Soc. 1993, 93 - 23 (Proc. Symp. New Sealed Rech. Batt. and Supercapacitors, 1993, 389 - 400)).

[0011] Lithium peroxide (Li 2 O 2 ) can be obtained by reacting with a mixed conductive LiNi 0.33 Co 0.33 Mn 0.33 O 2Co - grinding to contact and cathodically fully decompose (Y. Bie et al., Chem. Commun. 2017, 53, 8324 - 7). A composite material composed of a mixture of Co metal and Li 2 O (both in the form of nanoparticles) can also be cathodically fully decomposed (Y. Sun, Nature Energy, January 2016, 15008). The actual functionality of a complete battery cell containing nanoscale lithium oxides (a mixture of Li 3 O 4 embedded in a Co 2 O matrix, Li 2 O 2 and LiO 2 ) is known (Z. Zhu, Nature Energy, July 25, 2016, 16111). To avoid the release of oxygen from the lithium oxides, the charging voltage cannot exceed approximately 3 - 3.5 V relative to Li / Li + .

[0012] However, for commercialization, using lithium oxides as cathode active materials has practical drawbacks. The crystalline form of lithium superoxide (LiO 2 ) is thermodynamically unstable and decomposes into Li 2 O 2 and oxygen (K. C. Lau, Phys. Chem. C 115, 23625 - 33). Lithium peroxide is a strong oxidizer and decomposes and releases oxygen when in contact with water. Thus, neither of these two compounds can be safely handled on a large scale. Lithium oxide Li 2 O, although thermodynamically stable, is not commercially available. It is highly corrosive and can only be obtained through energy - intensive processes, such as the thermal decomposition of Li 2 CO 3 at temperatures above approximately 1000 °C (R. B. Poeppel, Advances in ceramics, Volume 25, "Fabrication and properties of lithium ceramics", edited by I. J. Hastings and G. W. Hollenberg, 1989, 111 - 116).

[0013] Problems to be Solved

[0014] The problem to be solved by the present invention is to provide a manufacturing method and an electrochemical energy storage system that can ensure an energy density of at least 500 Wh / kg, which is particularly high enough for mobile applications. In addition, active materials that are easily commercially available and can be safely managed should be used, which have the lowest possible content of rare or difficult - to - obtain metals.

[0015] Solution to the problem

[0016] The problem is solved by a method for manufacturing a rechargeable high-energy battery with an anion redox-active composite cathode, wherein the anion redox-active composite cathode contains lithium hydroxide as an electrochemically active component, the lithium hydroxide is mixed and contacted with an electronically or mixed-conductive transition metal and / or transition metal oxide to form an electronically or mixed-conductive network structure, this mixture is applied to a current conductor, and the resulting composite cathode is placed together with a separator, a lithium-conductive electrolyte, and a lithium-containing anode in a battery housing, thereby obtaining an electrochemical cell. At least one initial forming cycle is carried out on the electrochemical cell. In the case of a rechargeable high-energy battery whose positive electrode (cathode) consists of a composite material, the composite material contains at least a lithium compound selected from the following: lithium hydroxide (LiOH) as an electrochemically active component, and optionally lithium oxide (Li 2 O), peroxide (Li 2 O 2 ), and / or lithium superoxide (LiO 2 ), and the cathode contains additional lithium hydride (LiH) at least after the first discharge cycle (i.e., in the lithium-rich state). This LiH is formed according to one of the reaction formulas (1) to (3), see below. The electrochemically active component is embedded in an electronically or mixed-conductive network structure that contains transition metal particles and / or electronically conductive transition metal oxides and optionally other conductivity-enhancing materials.

[0017] At least the lithium compound lithium hydroxide (LiOH) and optionally another lithium compound selected from Li 2 O, Li 2 O 2 and LiO 2 are used for producing an electrochemically active composite cathode material. Lithium hydroxide is commercially available and easy and safe to handle. Based on the total content of the above lithium compounds, the proportion of LiOH in the composite cathode material is at least 10 mol%, preferably at least 30 mol%.

[0018] The negative electrode (anode) contains at least one lithium-supplying component or compound having an electrochemical potential <2V relative to the Li / Li + reference electrode. The lithium-supplying electrochemically active component or compound is selected from metallic lithium, lithium-containing metal alloys, lithium nitride transition metal compounds, or composite materials whose electrochemically active component is a metal nitride embedded in an electronically or mixed-conductive network structure containing a transition metal.

[0019] When manufacturing a rechargeable high-energy battery, preferably a secondary lithium battery comprising a composite cathode and anode according to the present invention, attention must be paid to the fact that the electrochemical potential of the active material of the anode relative to Li / Li + is <2 V to ensure an appropriate balance (i.e., weight matching) between the two electrodes with respect to their respective electrochemically active components. An appropriate balance is characterized by the fact that the electrochemically active materials can be utilized as fully as possible. In the present case, this particularly means that, prior to the first discharge cycle, the anode contains a certain molar amount of electrochemically activatable, i.e., electrochemically extractable lithium from the anode, which corresponds to at least half, preferably at least the same, and particularly preferably at least twice the molar amount of the LiOH content in the composite cathode. This is explained below.

[0020] When LiOH is used in the cathode of a rechargeable lithium battery, in addition to lithium oxide (Li 2 O), lithium peroxide (Li 2 O 2 ), and / or lithium superoxide (LiO 2 ), lithium hydride (LiH) is also formed during the first discharge cycle. The general cathode half-reaction during the first discharge of a primary battery corresponds to at least one of the following three reaction equations:

[0021] LiOH + 2Li + + 2e - → Li 2 O + LiH (1)

[0022] 2LiOH + 2Li + + 2e - → Li 2 O 2 + 2LiH (2)

[0023] 2LiOH + Li + + e - → LiO 2 + 2LiH (3)

[0024] As a result of the first discharge reaction, in addition to lithium hydride, at least one lithium oxide compound is also formed, which has anionic redox activity and is an electrochemically active cathode material for subsequent cycles. The inventors have found, surprisingly, that reactions (1) to (3) occur only when sufficient electronic or mixed electronic / ionic contact of the lithium hydroxide particles is ensured. In addition to this, the lithium hydroxide particles should preferably be present in a finely powdered form (nanoparticles). This also applies to other lithium oxide compounds selected from Li 2 O, Li 2 O 2 and LiO 2 that may be present in the cathode material.

[0025] Since Li 2 O has the highest lithium content among the lithium oxides considered, a cathode with the highest theoretical electrochemical capacity can be formed. The reaction equation (1) with a molar ratio of 1:2 between LiOH and the lithium that can be extracted from the anode (i.e., electrochemically active) is particularly preferred.

[0026] In principle, the electrochemically active cathode material according to the invention present in a lithium-rich form after the first discharge cycle can also be prepared by mixing Li 2 O and / or another lithium oxide and LiH. However, mainly for practical reasons, this manufacturing variant is not very advantageous. Lithium hydride is unstable to reactive air components such as water vapor and carbon dioxide (decomposing to form lithium hydroxide or lithium carbonate). In addition, lithium oxide is not commercially available and requires energy-intensive manufacturing methods.

[0027] In subsequent charge-discharge cycles, furthermore, the electrode composition sometimes undergoes irreversible changes. Contrary to the prior art (Z. Zhu, Nature Energy, July 25, 2016, 16111), the cathode according to the invention contains lithium hydride at least after the first discharge (i.e., in the lithium-rich state). Surprisingly, the lithium hydride formed during the first discharge cycle decomposes smoothly during subsequent charge cycles, presumably according to the following reaction:

[0028] LiH → 1 / 2H 2 + Li + + e - (4)

[0029] In addition to hydrogen gas, lithium is also released.

[0030] Rechargeable lithium batteries need to prevent contact with reactive gases and compounds of metallic lithium for operation. Air components such as oxygen, nitrogen, carbon dioxide, water vapor, and other trace air components are reactive towards lithium. Therefore, rechargeable lithium batteries usually have to be operated in a closed state (i.e., filled in a hermetically sealed housing). In the present case, hydrogen gas is formed at least during the first charge cycle. The hydrogen gas formed does not react with metallic lithium at moderate temperatures but causes an undesirable pressure to form in the hermetically sealed battery cell. To avoid this undesirable effect, at least the first discharge / charge cycle and, if necessary, further discharge / charge cycles must be performed in an open state. This procedure during one or more first cycles (so-called forming cycles) is a known procedure. To avoid excessive contact of the battery contents with the environment, pressure equalization is usually carried out by means of open capillaries, which are closed after one or more gas-forming reactions are completed.

[0031] During the first charging cycle, the lithium formed passes through the separator in the form of cations to the anode, where it is deposited in the metallic state or reacts with substances or compounds present there that are capable of receiving lithium. This can be at least a partially reversible reaction, for example, reacting with graphite materials, metals that receive lithium when forming alloys, lithium-poor metal alloys, and lithium-poor forms of lithium transition metal nitrides and / or composite materials, the electrochemically active component of which is a metal nitride compound embedded in an electronically or mixed-conducting network structure containing transition metals. However, irreversible reactions may also be involved, such as electrolyte decomposition and / or the formation of a passivation layer on the surface of particulate or flaky metal components (especially their electrochemically active components) at the anode. The lithium irreversibly consumed in this way indirectly increases the gravimetric capacity of the rechargeable lithium battery cell, because otherwise lithium from another source would have to be used for this purpose, such as lithium oxides selected from Li 2 O, Li 2 O 2 、LiO 2 and / or another cathode material such as lithium transition metal oxides. In the case of lithium hydride, the hydrogen gas generated during lithium release (which is non-reactive with respect to the remaining battery components, especially the electrolyte) escapes from the battery cell, while in the case of the lithium oxides, oxygen is generated that reacts with the electrolyte. If the lithium used for passivation or protective layer formation is derived from the lithium transition metal oxide introduced into the cathode, the delithiated material, i.e., Li x-δ MO y (δ = 0 to x; x and y can take values between 1 and 10) or the completely lithium-free transition metal oxide remains. Due to the lack of lithium, it can no longer participate in the battery redox process and thus represents an electrochemically inert substance that reduces the energy density of the system. In this case, the lithium hydride formed according to the invention is used as a first-class prelithiation agent.

[0032] During the cycling of a rechargeable electrochemical cell, the half-reactions occurring at the cathode are schematically as follows:

[0033]

[0034]

[0035]

[0036] (5) to (7) read from left to right are the discharge reactions. The double arrows indicate that these reactions are reversible processes (provided there is sufficient electronic or mixed contact).

[0037] Selected from lithium hydroxide (LiOH), lithium oxide (Li 2 O), lithium peroxide (Li 2 O2 ) and / or lithium superoxide (LiO 2 ) and optionally lithium hydride (LiH) must be embedded in an electronically or mixed-conducting network structure, which consists of finely divided transition metal particles and / or finely divided conducting transition metal oxide compounds having an electrochemical potential (lithium insertion potential) > 2V relative to Li / Li + . It is important to ensure the closest possible contact between the electrochemically active lithium compound and the transition metal or conducting transition metal oxide having an electrochemical potential > 2V. It is also advantageous that the latter and the electronically or mixed-conducting transition metal oxide compounds having an electrochemical potential > 2V relative to Li / Li + are present in as finely divided a form as possible, i.e., amorphous or nanoparticle form. The exact size of the preferred nanoparticle moldings depends on the mechanical shape factor (i.e., the three-dimensional shape of the particles). In the case of spherical (or similar) particle shapes, they are 0.1 - 100 nm, preferably 1 - 30 nm.

[0038] The solid components of the cathode composite can be crushed and brought into close contact with each other by a grinding process, preferably using a high-energy grinder. Using a planetary ball mill, nanoparticles of lithium oxide compounds and electronically or mixed-conducting transition metals or transition metal oxide compounds having an electrochemical potential > 2V relative to Li / Li + are obtained in this way. The nanoparticle particle morphology can also be produced by alternative physical methods (vapor deposition, plasma, and laser methods) or chemical methods, such as solvent-based methods, preferably the sol / gel method.

[0039] In the cathode, on the one hand, the finely divided transition metal and / or electronically or mixed-conducting transition metal oxide compounds and on the other hand the active material based on lithium oxide compounds selected from LiOH, Li 2 O, Li 2 O 2 and LiO 2 are in a molar ratio in the range of 1:100 to 1:1, preferably 1:50 to 1:1.5.

[0040] The transition metal M is preferably an element from Group 3 to Group 12 of the Periodic Table of the Elements, particularly preferably M = Sc, Ti, Zr, Hf, V, Cr, Mo, W, Mn, Fe, Ni, Co, Cu, Ag, Zn, and the rare earth metals La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, TM, Yb, and Lu or any mixture of the above transition metals.

[0041] The electronically conducting transition metal oxides in which M = a metal from Group 3 to Group 12 of the Periodic Table of the Elements are used as the transition metal oxide compounds. Binary (MOx ) and ternary (MM' y O x ) and higher mixed phases, wherein the other metal M' is at least another transition metal of Groups 3 to 12 of the Periodic Table of the Elements and / or the element lithium (Li y MO x ). In this case: w, y = 0 to 8; x = 0.5 to 4.

[0042] Preferably, the following metal oxide compounds are used: binary metal oxides such as titanium oxides (TiO, Ti 2 O 3 ), vanadium oxides (V 2 O 3 , VO, VO 2 ), iron oxides (Fe 3 O 4 , FeO), cobalt oxides (CoO 2 , Co 3 O 4 ), nickel oxides (Ni 2 O 3 ), manganese oxides (MnO 2 , Mn 3 O 4 ), chromium oxides (CrO 2 , Cr 3 O 3 ), niobium oxides (NbO); layered lithium metal oxides (LiCoO 2 , LiNiO 2 , Li(Ni,Mn,Co)O 2 ), LiV 3 O 8 ; spinel-structured lithium metal oxides (LiMn 2 O 4 , LiMnNiO 2 , LiNi 0.5 Mn 1.5 O 4 , LiV 3 O 5 ); inverse spinel-structured lithium metal oxides (LiNiVO 4 , LiCoVO 4 ); olivine-structured lithium metal oxides (LiFePO 4 , LiVPO 4)。The chemical formulas listed above represent the ideal composition of the alkaline compounds. However, in practice, they are used in a slightly or strongly modified form. These include materials with structurally stabilizing dopants (e.g., aluminum-stabilized lithium nickel cobalt oxide, "NCA") or compounds doped with foreign metals or non-metals to increase conductivity. Such variants of the parent compound modified by doping can also be used if applicable to the present invention.

[0043] Particularly preferably, electronically or mixed-conductive transition metal oxides and lithium transition metal oxides that can reversibly release and insert lithium are used. In these cases, if the electrochemical potential of these conductivity enhancers is approximately the same as the electrochemical potential (about 3 V) of the electrochemically active lithium oxide compound, their additional electrochemical capacity can be used. The metal oxide compounds available according to the present invention have a conductivity of at least 10 -7 S / cm, preferably at least 10 -6 S / cm, and particularly preferably at least 10 -5 S / cm.

[0044] The high-energy rechargeable battery according to the present invention has a negative electrode (anode) that contains a material with an electrochemical potential < 2 V relative to Li / Li + . These can be: graphite materials (graphite itself, hard carbon, graphene, etc.); metallic lithium; elements capable of alloying with lithium (e.g., aluminum, silicon, germanium, tin, lead, boron, zinc, mixtures thereof) and lithium-containing compounds of said metallic elements; transition metal nitrides (metal nitrides) ( MM' y N x ), where M = a metal from Groups 3 to 12 of the Periodic Table of the Elements, and M' = at least one other transition metal from Groups 3 to 12 of the Periodic Table of the Elements and / or elemental lithium, (Li y MN x ) and where y = 0 to 8; x = 0.5 to 1; metal nitride compounds of the following general formula

[0045] LiM 2 z (NH) 0.5x+z (I), and

[0046] Li m M 2 n (NH 2 ) 1+n (II), where

[0047] (I) and (II) can be present in any mixing ratio, and

[0048] M 2 = alkaline earth metal elements (Mg, Ca, Sr, Ba, or any mixture thereof), and

[0049] x = 0 - 4; z = 0 - 2

[0050] m = 1 or 0; n = 1 or 0, where (m + n) = 1.

[0051] In the fully charged (most lithium-rich) state, the metal nitride corresponds to the general formula (III) and / or (IV)

[0052] Li 2z+x M 2 z (NH) 0.5x+z (III)

[0053] Li 3 N.n(LiM 2 N).(4 - 2m)LiH (IV), where

[0054] (III) and (IV) can exist in any mixing ratio, and

[0055] M 2 = alkaline earth metal element (Mg, Ca, Sr, Ba or any mixture thereof)

[0056] x = 0 - 4; z = 0 - 2

[0057] m = 1 or 0; n = 1 or 0, where (m + n) = 1.

[0058] The metal nitride is preferably used as an electrochemically active anode material, wherein the metal nitride is embedded in an electronically or mixed-conducting network structure containing a transition metal. The electrochemically active metal nitride has a composition in a fully discharged (most lithium-poor) charge state, which is represented by at least one of the two general formulas (I) and / or (II). The electronically or mixed-conducting network structure containing a transition metal contains fine powder of the transition metal M in elemental form or a fine powder of a conducting interstitial transition metal compound with an electrochemical potential (lithium insertion potential) < 2.5 V relative to Li / Li + .

[0059] The transition metal powder M is preferably an element of Groups 3 to 12 of the Periodic Table, particularly preferably M = Sc, Ti, Zr, Hf, V, Cr, Mo, W, Mn, Fe, Co, Ni, Cu, Ag, Zn and the rare earth metals La, Ce, Pr, Nd, Sm, Gd, Dy, Ho, Er, Tm, Yb and Lu or any mixture of the above transition metals.

[0060] Relative to Li / Li +Electronically conductive interstitial compounds having an electrochemical potential (lithium insertion potential) of <2.5 V are used as transition metal compounds. These are preferably transition metal nitrides (metal nitrides) and / or transition metal carbides, each where M = a metal from Groups 3 to 12 of the Periodic Table of the Elements, and / or transition metal hydrides, where M = a metal from Groups 3 to 10 of the Periodic Table of the Elements. Binary (MN x , MC x , MH x ) and ternary (MM' y N x ; MM' y C x ; MM' y H x ) and higher mixed phases can be used, where the additional metal M' is at least one additional transition metal from Groups 3 to 12 of the Periodic Table of the Elements (M x M' y N z ) and / or elemental lithium (Li y MN x ; Li y MC x ; Li w M x M' y N z ; Li w M x M' y H z ; etc.). In this case: w, y = 0 to 8; x = 0.5 to 1; z = 0 to 3.

[0061] In the discharged (lithium - poor) state according to general formula (I), the metal nitride is preferably composed of at least one of the following compounds: Li 2 NH, MgNH, CaNH, Li 2 Mg(NH) 2 , Li 2 Ca(NH) 2 , MgCa(NH) 2 , Li 4 Mg(NH) 3 , Li 2 Mg 2 (NH) 3 and / or one or more of the following compounds according to general formula (II): LiNH 2 , Mg(NH 2 ) 2 , Ca(NH 2 ) 2 .

[0062] If the high-energy battery according to the present invention is charged by applying an external voltage, the anode material containing active N becomes a more lithium-rich state. When fully charged, the following lithium-rich compounds are formed, according to the general formula (III), preferably: Li 4 NH, Li 2 MgNH, Li 2 CaNH, Li 6 Mg(NH) 2 、Li 6 Ca(NH) 2 、Li 4 MgCa(NH) 2 、Li 10 Mg(NH) 3 、Li 8 Mg 2 (NH) 3 and / or according to the general formula (IV), preferably: Li 3 N, MgLiN, CaLiN and LiH.

[0063] The above transition metal compounds having a qualitative composition of Li w M x M' y E z (E = N, C, H; w, y = 0 to 8; x = 0.5 to 1; z = 0 to 3) belong to the group of so-called interstitial metal compounds or alloys, that is, the foreign element E as carbon, nitrogen or hydrogen is arranged on the interstitial layer (interstitial sites) of the following metal lattice. The stoichiometries shown respectively represent the highest contents (limiting stoichiometries) of carbon, nitrogen or hydrogen. However, interstitial compounds are not completely stoichiometric compounds, that is, all compositions from pure metals to the limiting stoichiometry are usually possible and most are stable. All compounds with a lower content of foreign elements, that is, qualitatively represented as Li w M x M' y E z-δ (δ can take any value between 0 and z) are also all electron- or mixed-conductive materials and are therefore suitable for manufacturing nitrogen-containing composite anode materials.

[0064] Preferably, an electronically conductive transition metal or its corresponding electronically conductive nitride, carbide or hydride compound is used in a finely divided form (nanoparticles). They can be mixed as uniformly as possible with the lithium-containing nitrogen anode material, also in the form of nanoparticles, by a physical mixing process, so as to ensure good contact between the individual particles by subsequent pressing (usually by rolling in the technical manufacturing process) during anode stripping production and to obtain a fully functional nitrogen-containing and transition metal-containing composite anode material. Suitable composite anode materials can also be produced by chemical methods, for example by reaction with a nitrogen source. Preferred nitrogen sources are elemental nitrogen (N 2 ); ammonia (NH 3 ); hydrazine (N 2 H 4 ); urea (CH 4 N 2 O). When ammonolysis is carried out with NH 3 ammonia, the metals, namely lithium and the selected transition metal, preferably react with ammonia under elevated temperature and pressure conditions. The amide compounds obtained can then be further converted, for example, into imide compounds and / or nitrides by subsequent pyrolysis. If a non-nitride conductivity enhancer is required, appropriate transition metal hydrides and / or transition metal carbides can be added before or after ammonolysis. After removing the excess ammonia, the remaining solids can be ground together. This measure reduces the particle size and improves the contact. During the reaction with nitrogen at most elevated temperatures and pressures, the nitride phase is formed immediately. Also in this case, the required non-nitride conductivity enhancer can be added.

[0065] In a preferred embodiment of the invention, the lithium-containing nitrogen anode material is co-ground with a conductivity-enhancing transition metal or nitride, carbide or hydride. Grinding is carried out using a high-energy grinder of the planetary ball mill type, for example.

[0066] Other materials that improve the anode function can be added to the nitrogen-containing composite anode material. These first include non-metal-based conductivity enhancers, lithium-providing additives and binders. All electrically conductive forms of elemental carbon (graphite, carbon black, graphene, carbon nanotubes) are suitable as non-metal-based conductivity enhancers. Lithium metal (preferably coated, i.e. surface passivated and in the form of powder or thin foil) or lithium-rich compounds such as lithium graphite (LiC 6-δ , δ = 0 - 5) or coated lithium silicide (Li n SiO x @Li 2 O) can be used as lithium-providing additives. Organic polyamides commonly used in electrode manufacture can be used as binders. These include PTFE, PVdF, polyisobutene (e.g. from BASF ) and similar materials. In the composite negative electrode material containing nitrogen and transition metals, on the one hand, fine powdered transition metals or electronically or mixed-conducting transition metal compounds Li w M x M' y E z (E = N, C, H; w, y = 0 to 8; x = 0.5 to 1; z = 0 to 3) and on the other hand, the weight ratio of the electrochemically active nitrogen-containing anode material containing nitrogen is generally between 1:100 and 1:2. It is preferably between 1:50 and 1:5. The ready-to-use (fully) nitrogen- and transition metal-containing composite anode may also contain other conductivity improvers (up to 30% by weight), binders (up to 20% by weight), and / or prelithiation agents (up to 20% by weight).

[0067] It is also preferred to use an anode containing metallic lithium, where the lithium is present in the form of sheet metal or powder electrodes or in the form of an alloy with metals selected from silicon, tin, boron, and aluminum.

[0068] As the electrolyte of the rechargeable high-energy battery according to the invention having an anion redox-active composite cathode, where in the state before the first discharge, the composite cathode contains lithium hydroxide embedded in an electronically or mixed-conducting network structure, and optionally one or more other lithium oxides selected from Li 2 O, Li 2 O 2 and LiO 2 can be of types well known to those skilled in the art (liquid, gel, polymer, and solid electrolytes). As the conductive salts for liquid, polymer, and gel-polymer systems, soluble lithium salts having weakly coordinating, oxidation-stable anions are used in the matrices employed. These include, for example, LiPF 6 , lithium fluoroalkyl phosphates, LiBF 4 , imide salts (such as LiN(SO 2 CF 3 ) 2 ), LiOSO 2 CF 3 , methide salts (such as LiC(SO 2 CF 3 ) 3 ), LiClO 4 , chelated lithium borates (such as LiB(C 2 O 4 ) 2 , also known as "LiBOB"), fluorinated chelated lithium borates (such as LiC 2 O 4 BF 2 , called "LiDFOB"), chelated lithium phosphates (such as LiP(C 2 O4 ) 3 , referred to as "LiTOP") and lithium fluorinated chelate phosphate (such as Li(C 2 O 4 ) 2 PF 2 ). Salts of anions that are particularly preferably stable against dissociation and fluorine-free anions are preferred.

[0069] Solid electrolytes, namely lithium ion-conductive glasses, ceramics or crystalline inorganic solids, are also particularly preferred. Examples of such materials are: lithium thiophosphate (such as Li 3 PS 4 ), argyrodite (Li 6 PS 5 X, where X = Cl, Br, I), phosphosilicate (such as Li 2 SiP 2 ), nitrogen phosphate (such as Li 2.9 PO 3.3 N 0.36 ), nitrogen boron phosphate (such as Li 47 B 3 P 14 N 42 ), metal sulfide phosphate (such as Li 10 GeP 2 S 11 ), garnet (such as Li 7 La 3 Zr 2 O 12 ), titanium phosphate (Li 1.5 Al 0.5 Ti 1.5 (PO 4 ) 3 ) and borohydride compounds (such as LiBH 4 and Li 2 B 12 H 12 ).

[0070] The anode chamber is separated from the cathode chamber by a diaphragm permeable to lithium ions but electrically insulating (e.g., composed of microporous polyolefin) or a solid electrolyte (inorganic solid or solid polymer material type).

[0071] The present invention is illustrated by the following examples:

[0072] Example 1: Preparation of a composite cathode containing lithium hydroxide by grinding (transition metal oxide and carbon black as conductivity enhancers)

[0073] In a glove box filled with Ar, 0.9 g of Co 3 O 4(<50 nm, supplier Aldrich), 3.6 g of anhydrous lithium hydroxide powder (supplier Albemarle Germany), and 0.2 g of carbon black (AB 400) were premixed in a beaker. The homogenized mixture was loaded into a 50 mL zirconia ceramic grinding beaker together with approximately 27 g of 3 mm zirconia ceramic balls and sealed. The mixture was then milled in a planetary ball mill (Pulverisette P7, from Fritsch) at 900 revolutions per minute (rpm) for 240 minutes.

[0074] The grinding jar was returned to the Ar-filled glove box and opened there. The milled product was separated from the grinding media by sieving.

[0075] Yield: 4.1 g of fine powder

[0076] Example 2: Preparation of a lithium hydroxide-containing composite cathode by a solvent-based method (transition metal oxide as conductivity enhancer)

[0077] 1.2 g of cobalt chloride (97%, from Aldrich), 0.69 g of lithium peroxide (>93%, from Albemarle Germany), and 3.6 g of anhydrous lithium hydroxide powder (Albemarle Germany) were dissolved or suspended in 50 ml of absolute ethanol and homogenized for 15 minutes using a high-energy stirrer (Ultraturrax IKA T 65). The resulting suspension was magnetically stirred at room temperature for 4 hours and then filtered.

[0078] The filter residue was first pre-dried in vacuo and then sintered in an oxygen atmosphere at 300 °C for 5 hours.

[0079] Yield: 3.6 g of fine powder

[0080] The powder contains 15% Co 3 O 4 and approximately 73% LiOH; the remainder to 100% consists essentially of lithium oxide.

Claims

1. A method for producing a rechargeable high-energy battery having an anion redox-active composite cathode, characterized in that, the cathode comprises lithium hydroxide as an electrochemically active component, and the method comprises: mixing and contacting a lithium oxide compound comprising at least LiOH and optionally lithium oxide, lithium peroxide and / or lithium superoxide with an electronically or mixed-conducting transition metal and / or transition metal oxide to form an electronically or mixed-conducting network structure, wherein, based on the total content of the lithium oxide compound, the proportion of LiOH in the lithium oxide compound is at least 10 mol%, applying the electronically or mixed-conducting network structure to a current conductor to form a composite cathode, placing the composite cathode together with a separator, a lithium-conducting electrolyte and a lithium-containing anode in a battery housing to form an electrochemical cell, and performing at least one initial forming cycle on the electrochemical cell.

2. The method according to claim 1, characterized in that, based on the total content of the lithium oxide compound, the proportion of LiOH in the lithium oxide compound is at least 30 mol%.

3. The method according to claim 1 or 2, characterized in that, the electronically or mixed-conducting transition metal and / or transition metal oxide is used in a molar ratio of 1:100 to 1:1 with the lithium oxide compound, and wherein the transition metal and / or transition metal oxide is in a fine powder form.

4. The method according to claim 1 or 2, characterized in that, the transition metal is selected from the elements of Groups 3 to 12 of the Periodic Table of the Elements or any desired mixture of the transition metals.

5. The method according to claim 1 or 2, characterized in that, the transition metal oxide is selected from: binary metal oxides, layered lithium metal oxides, spinel-structured lithium metal oxides, inverse spinel-structured lithium metal oxides and / or olivine-structured lithium metal oxides.

6. The method according to claim 5, characterized in that, The binary metal oxides are selected from titanium oxides, vanadium oxides, iron oxides, cobalt oxides, nickel oxides, manganese oxides, chromium oxides, niobium oxides; the layered lithium metal oxides are selected from LiCoO 2 、LiNiO 2 、Li(Ni,Mn,Co)O 2 、LiV 3 O 8 ; the spinel lithium metal oxides are selected from LiMn 2 O 4 、LiMnNiO 2 、LiNi 0.5 Mn 1.5 O 4 、LiV 3 O 5 ; the inverse spinel lithium metal oxides are selected from LiNiVO 4 、LiCoVO 4 , and the olivine lithium metal oxides are selected from LiFePO 4 、LiVPO 4 .

7. The method according to claim 1 or 2, characterized in that, the transition metal and / or the transition metal oxide is present in a fine powder form, amorphous or in the form of nanoparticles, wherein the particle size is in the range of 0.1 - 100 nm.

8. The method according to claim 1 or 2, characterized in that, metallic lithium is used as the anode, and the lithium is present in the form of sheet metal or powder electrode or in the form of an alloy with a metal selected from silicon, tin, boron and aluminum.

9. The method according to claim 1 or 2, characterized in that, before the first discharge cycle, an amount of lithium in moles electrochemically extractable from the anode is introduced into the anode, and the amount in moles corresponds to at least half of the amount in moles of the LiOH content present in the composite cathode.

10. The method according to claim 1 or 2, characterized in that, a non-metal-based conductivity enhancer and a binder are used in the anion redox-active composite cathode and optionally also in the anode.

11. The method according to claim 10, characterized in that, a graphite material is used as the non-metal-based conductivity enhancer, and the graphite material is selected from graphite, hard carbon, carbon black and graphene.

12. The method according to claim 1 or 2, wherein, both the anionic redox-active composite cathode and the anode are compacted by a pressing process or a calender.

13. The method according to claim 1 or 2, wherein, the solid components of the anionic redox-active composite cathode are brought into intimate contact with each other by being comminuted via a grinding process.

14. A high-energy battery having an anionic redox-active composite cathode, wherein, before the first electrochemical discharge, the cathode consists of a composite material comprising an electronically or mixed-conductive network structure, the network structure comprising a lithium oxide compound containing at least lithium hydroxide and optionally lithium oxide, lithium peroxide, and / or lithium superoxide, and an electronically conductive transition metal and / or transition metal oxide, wherein the electronically or mixed-conductive network structure component and the lithium oxide compound are present in a molar ratio of 1:100 to 1:

1.

15. The high-energy battery according to claim 14, wherein, The battery has an anode that includes at least one lithium-providing component or compound having an electrochemical potential of less than 2 V relative to a Li / Li + reference electrode, the lithium-providing component or compound being selected from metallic lithium, a lithium-containing metal alloy, a lithium-transition metal nitride, or a composite material having an electrochemically active component that is a metal nitride compound embedded in an electronically or mixed-conducting network structure containing a transition metal.

16. The method according to claim 1 or 2, wherein, the electronically or mixed-conductive transition metal and / or transition metal oxide and the lithium oxide compound are used in a molar ratio of 1:100 to 1:1, wherein the transition metal and / or transition metal oxide is in a fine powder form, and optionally wherein the transition metal and / or the transition metal oxide and lithium hydroxide are present in a uniformly mixed form as a fine powder, amorphous, or nanoparticle form, wherein the particle size is in the range of 0.1 - 100 nm.

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