Battery, method for pre-lithiating the battery and method for determining potentials of the electrodes of the battery

Abstract

The present invention relates to a battery. The present invention relates further to a method of pre-lithiating the battery. The present invention relates further to a method of determining potentials of the electrodes of the battery. The lithium electrode which is comprised in the battery, such as a pouch-type battery, in addition to a plurality of negative electrodes and a plurality of positive electrodes can be used for pre-lithiation by applying current to the lithium electrode and to one of the plurality of negative electrodes and the plurality of positive electrodes.

Description

[Rectified under Rule 91, 01.12.2025]BATTERY, METHOD FOR PRE-LITHIATING THE BATTERY AND METHOD FOR DETERMINING POTENTIALS OF THE ELECTRODES OF THE BATTERY

[0001] The present invention relates to a battery. The present invention relates further to a method of pre-lithiating the battery. The present invention relates further to a method of determining potentials of the electrodes of the battery.

[0002] State-of-the-art lithium-ion batteries (LIBs) suffer from active lithium loss (ALL) due to unavoidable side reactions. Energy density can therefore be even further increased by pre-lithiation, i.e. the introduction of active lithium into the negative or positive electrode before cell operation.

[0003] Many different pre-lithiation methods are already known with varying relevance for commercial battery production. For example, direct contact of the negative electrode with lithium metal is quick and easy to scale. This can be done by applying lithium metal powder or lithium metal foil. Although only the upper layers of the electrodes are pre-lithiated, these methods are commercially relevant as they are roll-to-roll (R2R) applicable.

[0004] In contrast to other pre-lithiation methods, in electrochemical pre-lithiation lithium ions are conducted through the electrolyte and electrons are conducted separately through an external circuit. The advantage is precise and homogeneous pre-lithiation, which, however, is relatively slow. R2R approaches are already known but not yet sufficiently understood and still part of research.

[0005] Nevertheless, these approaches are limited to ex situ. In situ pre-lithiation, i.e. pre-lithiation within the sealed cell, is often used in lithium-ion capacitors, where lithium metal is placed in parallel with the other electrodes. Sufficient ion transport can be ensured by using porous electrodes. However, the use of porous electrodes is limited to capacitors and cannot be applied to LIBs, as they would significantly reduce the energy density.

[0006] In general, the implementation of pre-lithiation methods in the commercial production of LIBs is challenging. One of the main reasons for this is the high reactivity of lithium metal and pre-lithiated electrodes, which require special safety measures. The pre-lithiation methods mentioned above are usually carried out in dry rooms, which are very expensive for production.

[0007] In addition, electrochemical pre-lithiation is more homogeneous and accurate if it can be carried out slowly. However, this is challenging for industrial production ex situ, as the speed of production would be significantly reduced (bottleneck of cell production).

[0008] In this respect, in situ pre-lithiation based on lithium-ion capacitors is of great interest, but not yet feasible.

[0009] It is, therefore, the object of the present invention to provide a lithium-ion battery and a method for pre-lithiating the same overcoming drawbacks of the prior art, especially allowing in-situ pre-lithiating of the lithium-ion battery

[0010] The above problem is solved in accordance with the independent claims. Further embodiments result from the sub claims and / or the following detailed description.

[0011] Especially, in order to achieve the above objects, the present disclosure provides, in a first embodiment, a battery comprising

[0012] - a plurality of negative electrodes;

[0013] - a plurality of positive electrodes;

[0014] - a separator;

[0015] - an electrolyte, and

[0016] - a lithium electrode;

[0017] wherein

[0018] the plurality of negative electrodes and the plurality of positive electrodes are alternately arranged.

[0019] According to a second embodiment of the present disclosure, in the first embodiment, the separator is arranged between the negative electrodes, the positive electrodes and the lithium electrode.

[0020] According to a third embodiment of the present disclosure, in the first embodiment or the second embodiment, the lithium electrode is a lithium layer.

[0021] According to a fourth embodiment of the present disclosure, in the third embodiment,

[0022] - the negative electrodes are negative electrode layers;

[0023] - the positive electrodes are positive electrode layers;

[0024] - the negative electrode layers and the positive electrode layers are arranged parallel to each other; and

[0025] - the lithium layer is arranged perpendicular to the negative electrode layers and the positive electrode layers.

[0026] According to a fifth embodiment of the present disclosure, in the third embodiment or the fourth embodiment, the battery further comprises a metal layer on one surface of the lithium layer.

[0027] According to a sixth embodiment of the present disclosure, in any of the first to the fifth embodiment, the battery is a pouch-type battery.

[0028] Furthermore, the present disclosure provides, in a sixth embodiment, a method of pre-lithiating a battery comprising the steps

[0029] - providing a battery according to any of the any of the first to the sixth embodiment; and

[0030] - transferring lithium ions from the lithium electrode to at least one of the positive electrodes and / or at least one of the negative electrodes.

[0031] Furthermore, the present disclosure provides, in a seventh embodiment, a method of determining potentials of the electrodes of a battery comprising the steps

[0032] - providing a battery according to any of the any of the first to the sixth embodiment; and

[0033] - determining the potentials of negative electrodes and / or the positive electrodes using the lithium electrode as a reference electrode.

[0034] Furthermore, the present disclosure provides, in an eighth embodiment, a battery comprising

[0035] - a plurality of negative electrodes;

[0036] - a plurality of positive electrodes;

[0037] - a separator;

[0038] - an electrolyte; and

[0039] - a lithium electrode;

[0040] wherein

[0041] the plurality of negative electrodes and the plurality of positive electrodes are alternately arranged; and

[0042] the plurality of negative electrodes and / or the plurality of positive electrodes is / are pre-lithiated.

[0043] This battery and the methods of the present invention overcome problems of current pre-lithiation methods described before and enable the in situ pre-lithiation of LIBs.

[0044] The lithium electrode which is comprised in the battery, such as a pouch-type battery, in addition to a plurality of negative electrodes and a plurality of positive electrodes can be used for pre-lithiation by applying current to the lithium electrode and to one of the plurality of negative electrodes and the plurality of positive electrodes. The speed of lithiation can therefore be precisely adjusted. The lithium ions migrate through the electrolyte and the separator to the respective connected electrode, analogous to a lithium metal battery.

[0045] In addition to pre-lithiation, the lithium electrode can also be used as a reference electrode to determine the potentials of the electrodes. This is not possible without the lithium electrode as a reference electrode, normally only the voltage of the battery can be measured. The identical setup is used to determine the potentials, only a significantly larger resistor is used in the electrical circuit.

[0046] The battery in accordance with the present invention makes it possible to pre-lithiate within the closed battery (in situ) by, for example, applying an electrical current to the current collectors of the additional electrode and preferably the negative electrode of the actual electrode stack, although the positive electrode would be possible as well. In this regard, an arrangement of the positive and negative electrodes in the form of stacked layers and the lithium electrode in the form of a layer perpendicular the stacked electrode layers brings the best pre-lithiation results.

[0047] A further advantage of the present invention is the avoidance of dry rooms during pre-lithiation, which makes the production of high energy batteries significantly cheaper. In addition, possible bottlenecks caused by pre-lithiation during production are prevented, making this method easier to integrate into current big-scale battery production. The advantages of electrochemical pre-lithiation (uniform, precise control over the degree of pre-lithiation) are also guaranteed, which significantly increases the number of cycles the cell can run. It also prevents potential safety risks during cell operation, i.e. short circuits due to dendrite growth.

[0048] Fig. 1 shows a battery according to one embodiment of the present invention.

[0049] Fig. 2a and 2b show enlarged sections of the battery according to the embodiment shown in Fig. 1

[0050] Fig. 3 shows a battery according to another embodiment of the present invention.

[0051] The terms and words used in the present specification and claims should not be construed as limited to ordinary or dictionary terms and should be construed in a sense and concept consistent with the technical idea of the present disclosure, based on the principle that the inventor can properly define the concept of a term to describe this invention in the best way possible.

[0052] Unless otherwise restricted, a detailed description defining or specifying the elements may be applied to all inventions and is not limited to descriptions of particular inventions. That is, the present disclosure also refers to combinations of the embodiments even if they are disclosed separately.

[0053] The terminology used herein is for the purpose of describing particular embodiments only and is not intended to be limiting of the invention. The singular forms "a," "an," and "the" comprise plural referents unless the context clearly dictates otherwise. It is to be understood that the terms such as "comprise" or "have" as used in the present specification, are intended to designate the presence of stated features, numbers, steps, operations, components, parts or combinations thereof, but not to preclude the possibility of the presence or addition of one or more other features, numbers, steps, operations, components, parts, or combinations thereof. The term "comprises" explicitly, even if not necessarily limited accordingly, includes the meaning "essentially comprising" and "consists of".

[0054] The term "essentially comprises" as used herein has the meaning of "comprising at least 70 %", preferably of "comprising at least 80 %", most preferred of "comprising at least 90 %". If reference is made to the amount of a constituent in a mixture of material, % is wt %, relative to the total weight of the respective mixture. For example, a material essentially comprising silicon comprises the silicon in an amount of at least 70 wt% with respect to the total weight of the material.

[0055] Additionally, the terms "about" and "substantially" as used herein are used in the sense of at, or nearly at, when given the manufacturing and material tolerances inherent in the stated circumstances and are used to prevent the unscrupulous infringer from unfairly taking advantage of the present disclosure where exact or absolute figures are stated as an aid to understanding the present disclosure.

[0056] As used herein, "A and / or B" means "A and B, or A or B".

[0057] Hereinafter, the present disclosure will be described in more detail.

[0058]

[0059] Battery

[0060] The present invention provides a battery. The battery may be a lithium-ion battery. The battery may be a lithium-ion secondary battery.

[0061] The battery according to the present invention may be any type of battery known in the art, for example may be a cylindrical battery, a pouch-type battery, a coin-type battery etc. The battery according to the present invention may be a pouch-type battery.

[0062] A pouch-shaped battery cell includes a case formed of a laminate sheet. The pouch-shaped battery cell is often used due to easy deformation and an increase in energy density when stored and stacked.

[0063] The pouch-shaped battery is manufactured by shaping a laminated sheet including an outer coating layer, a metal layer, and an inner resin layer into a pouch-shaped battery case, receiving an electrode assembly including positive electrode(s), the negative electrode(s) and the separator in the pouch-shaped battery case, and sealing the pouch-shaped battery case.

[0064] The laminate sheet may have a more complex and varied layered structure depending on implementation of the laminate sheet and the environment to which the laminate sheet is applied.

[0065] To seal the pouch-shaped battery case, an outer periphery of the pouch-shaped battery case may be pressed using a heating block configured to provide heat and pressure. As a result, the inner resin layer may be melted, whereby inner resin layers of an upper case and a lower case, which are stacked on top of each other, are thermally fused to form a seal.

[0066] Also, the present disclosure provides a battery module comprising the pouched-type battery described above as a unit battery.

[0067] The battery module may be used as a power source for medium to large-sized devices requiring high temperature stability, long cycle characteristics, high-capacity characteristics, and the like.

[0068] Examples of such medium to large-sized devices may comprise, but are not limited to, a power tool powered and moved by an electric motor; an electric car including an electric vehicle (EV), a hybrid electric vehicle (HEV), a plug-in hybrid electric vehicle (PHEV), and the like; an electric two-wheeled vehicle including an electric bike (E-bike) and an electric scooter (E-scooter); an electric golf cart; a power storage system, etc.

[0069]

[0070] Negative electrodes

[0071] The battery according to the present invention comprises a plurality of negative electrodes, wherein "a plurality" means at least two. The battery according to the present invention may comprise 2 to 100 negative electrodes, such as about 20 to 70 negative electrodes, for example about 50 negative electrodes. The negative electrode as referred to herein may also be referred to as anode. In the following preferred materials and structure of an anode will be described with respect to one of the negative electrodes in the plurality of negative electrodes, wherein in the plurality of negative electrodes the anodes may be independently different or the same.

[0072] The anode comprises an anode active material. The anode active material may be a porous anode active material (= anode active materials having pores). The anode may essentially comprise or consist of the anode active material. Alternatively, only a part of the anode may essentially comprise or consist of the anode active material, for example one or more layers of the anode.

[0073] In one embodiment the anode (= negative electrode) comprises essentially comprises or consists of a current collector and an anode active material layer, wherein the anode active material layer is provided on at least one surface of the current collector. In such a case, the current collector is a negative electrode current collector. The anode active material layer comprises, essentially comprises or consists of the anode active material.

[0074] The anode may be manufactured by coating the anode active material on a negative electrode current collector and drying.

[0075] The negative electrode current collector may be manufactured with the thickness of 3 ㎛ to 500 ㎛. The negative electrode current collector is not limited to a particular type and may comprise any material having conductive properties without causing any chemical change to the corresponding battery, for example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless-steel surface treated with carbon, nickel, titanium or silver, and aluminum-cadmium alloy. The negative electrode current collector may have microtexture on the surface to improve the adhesion strength of the anode active material, and may come in various types, for example, films, sheets, foils, nets, porous bodies, foams and non-woven fabrics.

[0076] For example, the anode active material may comprise silicon, silicon-containing alloys; carbons such as non-graphitizing carbon and graphite-based carbon; metal composite oxides such as LixFe2O3(0≤x≤1), LixWO2(0≤x≤1), SnxMe1-xMe'yOz(Me: Mn, Fe, Pb, Ge; Me': Al, B, P, Si, Groups 1, 2 and 3 elements of the periodic table, halogen; 0<x≤1; 1≤y≤3; 1≤z≤8); tin-containing alloys; metal oxides such as SnO, SnO2, PbO, PbO2, Pb2O3, Pb3O4, Sb2O3, Sb2O4, Sb2O5, GeO, GeO2, Bi2O3, Bi2O4, and Bi2O5; and conductive polymers such as polyacetylene; preferably comprises, essentially comprises or consists of silicon.

[0077] The anode active material may include a binder. The binder included in the anode active material is usually added in an amount of 0.1 weight% to 30 weight% based on the total weight of the mixture comprising the porous anode active material. In an exemplary embodiment of the present application, the negative electrode binder may comprise at least one selected from the group consisting of a polyvinylidene fluoride-hexafluoropropylene copolymer (PVDF-co-HFP), polyvinylidene fluoride, polyacrylonitrile, polymethylmethacrylate, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regenerated cellulose, polyvinylpyrrolidone, polytetrafluoroethylene, polyethylene, polypropylene, polyacrylic acid, an ethylene-propylene-diene monomer (EPDM), a sulfonated EPDM, styrene butadiene rubber (SBR), fluorine rubber, polyacrylic acid and a material in which the hydrogen thereof is substituted with Li, Na, Ca, or the like, and may also comprise various polymers thereof.

[0078] The porous anode active material may have a porosity of at least about 10%, at least 20%, or at least 25%. The porous anode active material may have a porosity of 90% or less, 80 % or less, 70% or less, 60% or less, 50% or less 40% or less 35% or less, or 30 % or less. Preferably, porous anode active material has a porosity from 20% to 35%, more preferably from 25% to 30%, such as about 30%. Such a porosity of the porous anode active material is advantageous in view of the amount of Li which can be deposited in the porous anode active material and in view of the achieved capacity of a lithium secondary battery using such a porous anode active material. The term "porosity" used in the present specification refers to a fraction of voids in a structure over the total volume and is indicated in %, and may be used interchangeably with void fraction, degree of porosity or the like. In the present disclosure, the porosity may be measured by mercury permeation method (Hg porosimeter) according to ASTM D-2873 in the version at the priority date of the present application.

[0079]

[0080] Positive electrodes

[0081] The battery according to the present invention comprises a plurality of positive electrodes, wherein "a plurality" means at least two. The battery according to the present invention may comprise 2 to 100 positive electrodes, such as about 20 to 70 positive electrodes, for example about 50 positive electrodes. The positive electrode as referred to herein may also be referred to as cathode. In the following preferred materials and structure of an cathode will be described with respect to one of the positive electrodes in the plurality of positive electrodes, wherein in the plurality of positive electrodes the cathodes may be independently different or the same.

[0082] The cathode (positive electrode) may be manufactured by coating a positive electrode material comprising a mixture of a positive electrode active material comprising positive electrode active material particles, a conductive material and a binder on a positive electrode current collector, and the positive electrode material may further comprise a filler if necessary.

[0083] In general, the positive electrode current collector is manufactured with the thickness of 3 ㎛ to 500 ㎛, and is not limited to a particular type and may include any material having high conductivity without causing any chemical change to the corresponding battery, for example, one selected from stainless steel, aluminum, nickel, titanium, and aluminum or stainless steel surface treated with carbon, nickel, titanium or silver, and specifically aluminum. The current collector may have macrotexture on the surface to improve the adhesion strength of the positive electrode active material, and may come in various types, for example, films, sheets, foils, nets, porous bodies, foams and non-woven fabrics.

[0084] In addition to the positive electrode active material particles, the positive electrode active material may comprise, for example, layered compounds or compounds with one or more transition metal such as lithium nickel oxide (LiNiO2); lithium manganese oxide such as formula Li1+xMn2-xO4(x is 0 to 0.33), LiMnO3, LiMn2O3, LiMnO2; lithium copper oxide (Li2CuO2); vanadium oxide such as LiV3O8, LiV3O4, V2O5, Cu2V2O7; Ni site lithium nickel oxide represented by formula LiNi1-xMxO2(M = Co, Mn, Al, Cu, Fe, Mg, B or Ga, x = 0.01 to 0.3); lithium manganese composite oxide represented by formula LiMn2-xMxO2(M = Co, Ni, Fe, Cr, Zn or Ta, x = 0.01 to 0.1) or Li2Mn3MO8(M = Fe, Co, Ni, Cu or Zn); LiMn2O4with partial substitution of alkali earth metal ion for Li; disulfide compounds; Fe2(MoO4)3, but is not limited thereto.

[0085] The conductive material is usually added in an amount of 0.1 weight% to 30 weight% based on the total weight of the mixture comprising the positive electrode active material. The conductive material is not limited to any particular type when it has conductive properties while not causing a chemical change to the corresponding battery, and may include, for example, conductive materials, for example, graphite such as natural graphite or artificial graphite; carbon black such as acetylene black, ketjen black, channel black, furnace black, lamp black and thermal black; conductive fibers such as carbon fibers or metal fibers; fluorocarbon, metal powder such as aluminum powder and nickel powder; conductive whiskers such as oxide zinc and potassium titanate; conductive metal oxide such as titanium oxide; and polyphenylene derivatives.

[0086] The binder included in the positive electrode assists in binding the active material and the conductive material and binding to the current collector and is usually added in an amount of 0.1 weight% to 30 weight% based on the total weight of the mixture comprising the positive electrode active material. Examples of the binder may comprise polyvinylidene fluoride, polyvinyl alcohol, carboxymethyl cellulose (CMC), starch, hydroxypropyl cellulose, regeneratedcellulose, polyvinylpyrrolidone, tetrafluoroethylene, polyethylene, polypropylene, ethylene-propylene-diene terpolymer, styrene-butadiene rubber, fluorine rubber and various types of copolymers.

[0087]

[0088] Separator

[0089] The separator may be made of a porous non-conductive or insulating material that separates or insulates the positive electrode and the negative electrode from each other and enables transport of lithium ions between the positive electrode and the negative electrode. The separator may be used without special limitation as long as it is used as a separator in a conventional lithium-sulfur battery. The separator may be an independent member such as a film or may comprise a coating layer added to the positive and / or negative electrodes.

[0090] It is preferable that the separator has excellent wettability to the electrolyte while having low resistance to ion migration of the electrolyte.

[0091] The separator may be made of a porous substrate, and the porous substrate may be used as long as it is a porous substrate commonly used for a lithium-sulfur battery, and porous polymer films may be used alone or by laminating them, and for example, a nonwoven fabric or a polyolefin-based porous membrane made of glass fibers, polyethylene terephthalate fibers, etc. having a high melting point may be used, but is not limited thereto.

[0092] The material of the porous substrate is not particularly limited in the present disclosure, and any material can be used as long as it is a porous substrate commonly used in an electrochemical device. For example, the porous substrate may comprise at least one material selected from the group consisting of polyolefin such as polyethylene and polypropylene, polyester such as polyethyleneterephthalate and polybutyleneterephthalate, polyamide, polyacetal, polycarbonate, polyimide, polyetheretherketone, polyethersulfone, polyphenyleneoxide, polyphenylenesulfide, polyethylenenaphthalate, polytetrafluoroethylene, polyvinylidene fluoride, polyvinyl chloride, polyacrylonitrile, cellulose, poly(p-phenylene benzobisoxazole), and polyarylate.

[0093] The thickness of the porous substrate is not particularly limited, but may be 1 to 100 μm, preferably 5 to 50 μm. Although the thickness range of the porous substrate is not particularly limited to the above-mentioned range, when the thickness is excessively thinner than the lower limit described above, mechanical properties are deteriorated and thus the separator may be easily damaged during use of the battery.

[0094] The average diameter and porosity of the pores present in the porous substrate are also not particularly limited but may be 0.001 μm to 50 μm and 10% by volume to 95% by volume, respectively.

[0095]

[0096] Electrolyte

[0097] The electrolyte includes lithium ions and is intended to cause an electrochemical oxidation or reduction reaction in the positive electrode and the negative electrode through them.

[0098] The electrolyte may be a non-aqueous electrolyte solution or a solid electrolyte that does not react with lithium metal, but is preferably a non-aqueous electrolyte, and comprises an electrolyte salt and an organic solvent.

[0099] The electrolytic salt which is comprised in the non-aqueous electrolyte solution is lithium salt. The lithium salt can be used without limitation as long as it is commonly used in an electrolyte solution for a lithium secondary battery. For example, the lithium salt may be LiCl, LiBr, LiI, LiClO4, LiBF4, LiB10Cl10, LiPF6, LiCF3SO3, LiCF3CO2, LiAsF6, LiSbF6, LiAlCl4, CH3SO3Li, (CF3SO2)2NLi, LiN(SO2F)2, lithium chloroborane, lithium lower aliphatic carboxylate, tetra-phenyl lithium borate, lithium imide, etc.

[0100] The concentration of the lithium salt may be 0.2 to 2 M, preferably 0.4 to 2 M, more preferably 0.4 to 1.7 M depending on various factors such as the exact composition of the electrolyte solvent mixture, the solubility of the salt, the conductivity of the dissolved salt, the charging and discharging conditions of the battery, the operating temperature, and other factors known in the lithium battery field. When the concentration of the lithium salt is less than 0.2 M, the conductivity of the electrolyte may be lowered and thus the performance of the electrolyte may be deteriorated. When the concentration of the lithium salt is more than 2 M, the viscosity of the electrolyte may increase and thus the mobility of the lithium ion may be reduced.

[0101] As the organic solvent contained in the non-aqueous electrolyte solution, those conventionally used in an electrolyte solution for a lithium secondary battery may be used without limitation, and for example, ether, ester, amide, linear carbonate, cyclic carbonate, etc. may be used alone or in combination of two or more. Among them, representatively, ether-based compounds may be comprised.

[0102] The ether-based compound may comprise acyclic ethers and cyclic ethers.

[0103] For example, the acyclic ether may be, but is not limited to, at least one selected from the group consisting of dimethyl ether, diethyl ether, dipropyl ether, methylethyl ether, methylpropyl ether, ethylpropyl ether, dimethoxyethane, diethoxyethane, ethylene glycol ethylmethylether, diethylene glycol dimethyl ether, diethylene glycol diethyl ether, diethylene glycol methylethyl ether, triethylene glycol dimethyl ether, triethylene glycol diethyl ether, triethylene glycol methylethyl ether, tetraethylene glycol dimethyl ether, tetraethylene glycol diethyl ether, tetraethylene glycol methylethyl ether, polyethylene glycol dimethyl ether, polyethylene glycol diethyl ether, and polyethylene glycol methylethyl ether.

[0104] As an example, the cyclic ether may be, but is not limited to, at least one selected from the group consisting of 1,3-dioxolane, 4,5-dimethyl-dioxolane, 4,5-diethyl-dioxolane, 4-methyl-1,3-dioxolane, 4-ethyl-1,3-dioxolane, tetrahydrofuran, 2-methyltetrahydrofuran, 2,5-dimethyltetrahydrofuran, 2,5-dimethoxytetrahydrofuran, 2-ethoxytetrahydrofuran, 2-methyl-1,3-dioxolane, 2-vinyl-1,3-dioxolane, 2,2-dimethyl-1,3-dioxolane, 2-methoxy-1,3-dioxolane, 2-ethyl-2-methyl-1,3-dioxolane, tetrahydropyran, 1,4-dioxane, 1,2-dimethoxy benzene, 1,3-dimethoxy benzene, 1,4-dimethoxy benzene, and isosorbide dimethyl ether.

[0105] Examples of the ester of the organic solvent may be, but is not limited to, any one selected from the group consisting of methyl acetate, ethyl acetate, propyl acetate, methyl propionate, ethyl propionate, propyl propionate, γ-butyrolactone, γ-valerolactone, γ-caprolactone, σ-valerolactone, and ε-caprolactone, and a mixture of two or more thereof.

[0106] Specific examples of the linear carbonate compound may representatively be, but is not limited to, any one selected from the group consisting of dimethyl carbonate (DMC), diethyl carbonate (DEC), dipropyl carbonate, ethylmethyl carbonate (EMC), methylpropyl carbonate, and ethylpropyl carbonate, or a mixture of two or more thereof.

[0107] In addition, specific examples of the cyclic carbonate compound may be any one selected from the group consisting of ethylene carbonate (EC), propylene carbonate (PC), 1,2-butylene carbonate, 2,3-butylene carbonate, 1,2-pentylene carbonate, 2,3-pentylene carbonate, vinylene carbonate, vinylethylene carbonate, and halides thereof, or a mixture of two or more thereof. Examples of such halides comprise, but are not limited to, fluoroethylene carbonate (FEC) and the like.

[0108] The electrolyte may further include a nitric acid or nitrous acid-based compound as an additive in addition to the electrolyte salt and the organic solvent described above. The nitric acid or nitrite-based compound has an effect of forming a stable film on a lithium metal electrode, which is a negative electrode, and improving charging / discharging efficiency.

[0109] The nitric acid or nitrous acid-based compound is not particularly limited in the present disclosure, but may be at least one selected from the group consisting of inorganic nitric acid or nitrous acid compounds such as lithium nitrate (LiNO3), potassium nitrate (KNO3), cesium nitrate (CsNO3), barium nitrate (Ba(NO3)2), ammonium nitrate (NH4NO3), lithium nitrite (LiNO2), potassium nitrite (KNO2), cesium nitrite (CsNO2) and ammonium nitrite (NH4NO2); organic nitric acid or nitrous acid compounds such as methyl nitrate, dialkyl imidazolium nitrate, guanidine nitrate, imidazolium nitrate, pyridinium nitrate, ethyl nitrite, propyl nitrite, butyl nitrite, pentyl nitrite, and octyl nitrite; organic nitro compounds such as nitromethane, nitropropane, nitrobutane, nitrobenzene, dinitrobenzene, nitropyridine, dinitropyridine, nitrotoluene, dinitrotoluene, and combinations thereof, and preferably, lithium nitrate is used.

[0110] The injection of the electrolyte may be performed at an appropriate stage of the manufacturing processes of the electrochemical device, depending on the manufacturing process and required properties of the final product. That is, the injection can be performed before assembling the electrochemical device or at the final stage of assembling the electrochemical device.

[0111]

[0112] Lithium electrode

[0113] The lithium electrode comprises, essentially comprises or consists of metallic lithium. The lithium electrode may consist of metallic lithium and may be in the form of a lithium disc, ingot, foil, rod, layer etc., preferably in the form of a foil or a layer.

[0114] The lithium electrode may further comprise a current collector (16). The metallic lithium may be deposited, coated etc. on the current collector. The current collector may be manufactured with the thickness of 3 ㎛ to 500 ㎛. The current collector is not limited to a particular type and may comprise any material having conductive properties without causing any chemical change to the corresponding battery, for example, copper, stainless steel, aluminum, nickel, titanium, sintered carbon, copper or stainless-steel surface treated with carbon, nickel, titanium or silver, and aluminum-cadmium alloy. The current collector may have microtexture on the surface to improve the adhesion strength of the metallic lithium, and may come in various types, for example, films, sheets, foils, nets, porous bodies, foams and non-woven fabrics.

[0115]

[0116] Battery arrangement

[0117] The plurality of negative electrodes and the plurality of positive electrodes are alternately arranged.

[0118] The separator may be arranged between the negative electrodes, the positive electrodes and the lithium electrode. That is, the separator, respectively a plurality if separators, may be arranged between each of the alternating negative electrodes and positive electrodes; and at the same time, the separator is also arranged between, on the one hand, the plurality of negative electrodes and the plurality of positive electrodes and, on the other hand, the lithium electrode. It may be provided that all electrodes (positive electrodes, negative electrodes and lithium electrode) comprised in the battery are separated from each other by one or more separator(s).

[0119] The separator may be filled, that is, wetted, penetrated etc. by the electrolyte. That is, it may be provided that the separator filled with the electrolyte is arranged between the negative electrodes, the positive electrodes and the lithium electrode. In this way, a short circuit can be avoided but ion transport is enabled.

[0120] It may be provided that the lithium electrode is a lithium layer, that is, a lithium film, a lithium foil or a lithium layer, especially the uttermost layer, of a layer stack comprising the lithium layer.

[0121] In one embodiment, it is provided that

[0122] - the negative electrodes are negative electrode layers;

[0123] - the positive electrodes are positive electrode layers;

[0124] - the negative electrode layers and the positive electrode layers are arranged roughly parallel, essentially parallel or parallel to each other; and

[0125] - the lithium layer is arranged roughly perpendicular, essentially perpendicular or perpendicular to the negative electrode layers and the positive electrode layers.

[0126] Respective positioning of the electrodes, the separator and the electrolyte support the technical effect of the present invention, namely that it possible to pre-lithiate within the closed cell (in situ) by applying an electrical current to the current collectors of the additional electrode and preferably the negative electrode of the actual electrode stack, although the positive electrode is possible as well.

[0127] As a result of pre-lithiating in accordance with the method of the invention within the closed cell (in situ) by applying an electrical current to the current collectors of the additional electrode and the negative electrode and / or the positive electrode, a battery is obtained comprising

[0128] - a plurality of negative electrodes;

[0129] - a plurality of positive electrodes;

[0130] - a separator;

[0131] - an electrolyte; and

[0132] - a lithium electrode;

[0133] wherein

[0134] the plurality of negative electrodes) and the plurality of positive electrodes are alternately arranged; and

[0135] the plurality of negative electrodes and / or the plurality of positive electrodes is / are pre-lithiated.

[0136]

[0137] For example, the lithium electrode in the form of a layer may be attached to the side of a usual electrode stack. Lithium metal may therefore be located orthogonally to the actual positive and negative electrodes.

[0138] The battery may further comprise a metal layer (wherein the metal is not lithium) on one surface of the lithium layer, especially on the surface of the lithium layer opposite to the stack of the negative electrode layers and the positive electrode layers. For example, lithium metal on a foil of a different metal, such as a copper foil, can be used.

[0139] A metal connection, which is located partially outside of the pouch, may be attached to the lithium electrode or the further metal layer (such as the copper foil) functioning as an electrode tab.

[0140] Further metal connections, which is located partially outside of the pouch, may be attached to the one or more of the positive electrodes and to one or more of the negative functioning as electrode tabs.

[0141]

[0142] Method of pre-lithiating a battery

[0143] The method for preparing a pre-lithiated anode according to the present invention comprises a step of transferring lithium ions from the lithium electrode to at least one of the positive electrodes and / or at least one of the negative electrodes in the battery according to the present invention as described above.

[0144] The method for preparing a pre-lithiated anode according to the present invention may comprise a step of transferring lithium ions from the lithium electrode to at least one of the anodes in the battery according to the present invention as described above.

[0145] The step of transferring lithium ions from the lithium electrode to at least one of the anodes may comprise

[0146] - providing an external short circuit between the respective anode and the lithium electrode; or

[0147] - applying a current to the anode and the lithium electrode.

[0148] Preferably, the step of transferring lithium ions from the counter-electrode to the anode active material may comprise applying a current to the anode and the counter electrode, especially with a current density selected from the group consisting of from 0.01 to 1 mA*cm-2, from 0.02 to 0.9 mA*cm-2, from 0.03 to 0.8 mA*cm-2, from 0.04 to 0.7 mA*cm-2, from 0.05 to 0.6 mA*cm-2, from 0.06 to 0.5 mA*cm-2, from 0.07 to 0.4 mA*cm-2, from 0.08 to 0.15 mA*cm-2, and from 0.09 to 0.11 mA*cm-2, such as about 0.1 mA*cm-2.

[0149] The step of transferring lithium ions from the counter-electrode to the anode active material may be performed at a temperature selected from the group consisting of from room temperature (about 23°C) to 100°C, 40°C to 80°C, and 50°C to 70°C, such as about 60°C.

[0150]

[0151] Method of determining potentials of the electrodes of the battery

[0152] The method for preparing a pre-lithiated anode according to the present invention comprises a step of determining potentials of the electrodes of the battery according to the present invention as described above. The lithium electrode (used for its pre-lithiation capability) can also act as a "reference electrode". A "reference electrode" refers to an electrode with known electrode potential, in this case lithium metal. Electrode potentials of either the positive or negative electrode can be measured by electrically connecting the respective electrode, the reference electrode and an appropriate measuring device, such as one voltmeter or potentiostat.

[0153] The potential of the other electrode can be calculated with equation (1), after which the potentials of negative and positive electrodes are known.

[0154]

[0155] Ucell= Epositive electrode- Enegative electrode(1)

[0156]

[0157] The potential measurement can be carried out before, during and after battery operation, allowing the respective state of charge of the positive and negative electrodes to be determined, which enables better control of cell operation. This represents another advantage of using a lithium electrode in addition to the pre-lithiation mentioned above.

[0158]

[0159] Description of the figures

[0160] Hereinafter, a pouch-shaped battery cell according to the present invention and a battery module including the same will be described with reference to the accompanying drawings.

[0161] Referring to Fig. 1, a battery 10 in accordance with one embodiment of the present invention is shown. The battery as shown in Fig. 1 is a pouch-type battery. The battery 10 comprises in a pouch a plurality of negative electrodes 11 in the form of negative electrode layers. The battery 10 comprises further in the pouch a plurality of positive electrodes 12 in the form of positive electrode layers. The plurality of negative electrodes 11 and the plurality of positive electrodes 12 are alternately arranged.

[0162] The battery 10 comprises further a separator 13. The separator 13 is arranged between each of the alternating negative electrodes 11 and positive electrodes 12. An electrolyte (not shown) is filled into the separator 13, that is, the separator 13 is wetted with the electrolyte.

[0163] The battery 10 comprises further a lithium electrode 14. The lithium electrode 14 is arranged perpendicular to each of the alternating negative electrodes 11 and positive electrodes 12. The separator 13 is not only arranged between each of the alternating negative electrodes 11 and positive electrodes 12 but also between each of the alternating negative electrodes 11 and positive electrodes 12 and the lithium electrode 14.

[0164] The battery 10 comprises further electrode tabs 15 attached to the lithium electrode 14, one of the negative electrodes 11 and one of the positive electrodes 12. The electrode tabs 15 protrude and are located partially outside the pouch and allow to make electric contact to the electrode.

[0165] Before, pre-lithiation, that is, transferring lithium ions from the lithium electrode 14 to at least one of the positive electrodes 12 and / or at least one of the negative electrodes 11, the positive electrodes 12 and the negative electrodes 11 are not pre-lithiated, that is, are pristine electrodes.

[0166] During the pre-lithiation, lithium ions are transferred from the lithium electrode 14 to at least one of the positive electrodes 12 and / or at least one of the negative electrodes 11. Preferably to at least one of the negative electrodes 11, most preferred to all negative electrodes 11. As a result, the respective electrodes are pre-lithiated.

[0167] That is, according to a preferred embodiment, Fig. 1 shows the final product in the form of a battery 10 comprising in a pouch a plurality of pre-lithiated negative electrodes 11 in the form of pre-lithiated negative electrode layers. The battery 10 comprises further in the pouch a plurality of positive electrodes 12 in the form of positive electrode layers, a separator 13, a lithium electrode 14, and electrode tabs 15.

[0168] Fig. 2a and 2b show enlarged sections of the battery according to the embodiment shown in Fig. 1.

[0169] In detail, Fig. 2 shows a part of the battery 10 comprising in a pouch a plurality of negative electrodes 11 in the form of negative electrode layers and further comprising in the pouch a plurality of positive electrodes 12 in the form of positive electrode layers.

[0170] Before, pre-lithiation, the positive electrodes 12 and the negative electrodes 11 are not pre-lithiated, that is, are pristine electrodes. In a preferred embodiment of the final product, Fig. 2 shows a part of the battery 10 comprising in a pouch a plurality of pre-lithiated negative electrodes 11 in the form of pre-lithiated negative electrode layers. The battery 10 further comprises in the pouch a plurality of positive electrodes 12 in the form of positive electrode layers.

[0171] Referring to Fig. 3, a battery 10 in accordance with another embodiment of the present invention is shown.

[0172] Just as in Fig, 1, a battery 10 is shown in Fig. 3. The battery as shown in Fig. 3 is a pouch-type battery. The battery 10 comprises in a pouch a plurality of negative electrodes 11 in the form of negative electrode layers. The battery 10 comprises further in the pouch a plurality of positive electrodes 12 in the form of positive electrode layers. The plurality of negative electrodes 11 and the plurality of positive electrodes 12 are alternately arranged.

[0173] The battery 10 comprises further a separator 13. The separator 13 is arranged between each of the alternating negative electrodes 11 and positive electrodes 12. An electrolyte (not shown) is filled into the separator 13, that is, the separator 13 is wetted with the electrolyte.

[0174] The battery 10 comprises further a lithium electrode 14. The lithium electrode 14 is arranged perpendicular to each of the alternating negative electrodes 11 and positive electrodes 12. The separator 13 is not only arranged between each of the alternating negative electrodes 11 and positive electrodes 12 but also between each of the alternating negative electrodes 11 and positive electrodes 12 and the lithium electrode 14.

[0175] The battery 10 comprises further electrode tabs 15 attached to the lithium electrode 14, one of the negative electrodes 11 and one of the positive electrodes 12. The electrode tabs 15 protrude and are located partially outside the pouch and allow to make electric contact to the electrode.

[0176] In addition to the embodiment shown in Fig. 1, the battery 10 as shown in Fig. 3 further comprises a metal layer 16 on the surface of the lithium electrode 14 facing away from the stack of alternating negative electrodes 11 and positive electrodes 12. The electrode tab 15 is attached to the metal layer 16.

[0177] Before, pre-lithiation, that is, transferring lithium ions from the lithium electrode 14 to at least one of the positive electrodes 12 and / or at least one of the negative electrodes 11, the positive electrodes 12 and the negative electrodes 11 are not pre-lithiated, that is, are pristine electrodes.

[0178] During the pre-lithiation, lithium ions are transferred from the lithium electrode 14 to at least one of the positive electrodes 12 and / or at least one of the negative electrodes 11. Preferably to at least one of the negative electrodes 11, most preferred to all negative electrodes 11. As a result, the respective electrodes are pre-lithiated.

[0179] That is, according to a preferred embodiment, Fig. 1 shows the final product in the form of a battery 10 comprising in a pouch a plurality of pre-lithiated negative electrodes 11 in the form of pre-lithiated negative electrode layers. The battery 10 comprises further in the pouch a plurality of positive electrodes 12 in the form of positive electrode layers, a separator 13, a lithium electrode 14, and electrode tabs 15.

[0180] The features disclosed in the foregoing description and in the dependent claims may, both separately and in any combination thereof, be material for realizing the aspects of the disclosure made in the independent claims, in diverse forms thereof.

Claims

1.A battery (10) comprising- a plurality of negative electrodes (11);- a plurality of positive electrodes (12);- a separator (13);- an electrolyte; and- a lithium electrode (14);whereinthe plurality of negative electrodes (11) and the plurality of positive electrodes (12) are alternately arranged.2.The battery (10) according to claim 1, wherein the separator (13) is arranged between the negative electrodes (11), the positive electrodes (12) and the lithium electrode (14).3.The battery (10) according to claim 1 or 2, wherein the lithium electrode (14) is a lithium layer.4.The battery (10) according to claim 3, wherein- the negative electrodes (11) are negative electrode layers;- the positive electrodes (12) are positive electrode layers;- the negative electrode layers and the positive electrode layers are arranged parallel to each other; and- the lithium layer is arranged perpendicular to the negative electrode layers and the positive electrode layers.5.The battery (10) according to claim 3 or 4, wherein the battery (10) further comprises a current collector (16) on one surface of the lithium layer.6.The battery (10) according to any of the preceding claims, wherein the battery (10) is a pouch-type battery.7.A method of pre-lithiating a battery (10) comprising the steps- providing a battery (10) according to any of the preceding claims; and- transferring lithium ions from the lithium electrode (14) to at least one of the positive electrodes (12) and / or at least one of the negative electrodes (11).8.A method of determining potentials of the electrodes of a battery (10) comprising the steps- providing a battery (10) according to any of the claims 1 to 6; and- determining the potentials of negative electrodes (11) and / or the positive electrodes (12) using the lithium electrode (14) as a reference electrode.9.A battery (10) comprising- a plurality of negative electrodes (11);- a plurality of positive electrodes (12);- a separator (13);- an electrolyte; and- a lithium electrode (14);whereinthe plurality of negative electrodes (11) and the plurality of positive electrodes (12) are alternately arranged; andthe plurality of negative electrodes (11) and / or the plurality of positive electrodes (12) is / are pre-lithiated.

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