Anode-free battery cell

Abstract

The present invention relates to an anodeless battery cell comprising a cathode, an electrolyte and an electronic conductor provided on the anode side of the battery cell wherein the battery cell further comprises a high surface area substrate provided between the cathode and the electronic conductor, wherein at least a portion of the surface of the high surface area substrate contacts at least a portion of the surface of the electronic conductor, and wherein the high surface area substrate (4) has a porosity of at least 40% as measured by X-ray computed tomography, and wherein the high surface area substrate (4) comprises an organic compound and / or an inorganic compound comprising a lithium lanthanum zirconium oxide and / or a silica polymorph. The invention further relates to an anodeless battery comprising a stack of 2 to 20 anodeless cells according to the invention.

Description

[0001] Technical Field of the Invention

[0002] The present invention relates to an anode - free battery cell and an anode - free battery including a stack of anode - free battery cells.

[0003] Background

[0004] The development and improvement of batteries for various devices that require batteries, such as mobile phones, wireless household appliances, and electric vehicles and bicycles, have recently become an important area of research and interest. The secondary battery field, in particular, is progressing by developing smaller and lighter batteries with improved lifetimes.

[0005] In accordance with these recent developments, lithium secondary batteries having metallic lithium as an active material have attracted attention. Metallic lithium is known to have the characteristics of a low redox potential ( - 3.045 V relative to the standard hydrogen electrode) and a high weight energy density (3860 mAh / g), which makes metallic lithium an interesting material for the negative electrode (anode).

[0006] It is known to use metallic lithium as the negative electrode by connecting a lithium foil to an anode current collector. However, since lithium is an alkali metal, it reacts with water and oxygen due to its high reactivity. This has the disadvantage that such batteries are considered unsafe due to, for example, the risk of explosion when leaked to the environment. The handling of lithium foil is further dangerous.

[0007] In addition, when metallic lithium is exposed to the atmosphere, an oxide layer is usually formed due to oxidation. This oxide layer tends to act as an insulator, thereby increasing the resistance and thus reducing the performance of the battery.

[0008] To solve this problem, anode - free battery cells have been developed. Such battery cells generally include only an anode current collector and form (deposit) a lithium layer in - situ on the anode current collector during the first charge of the battery as the anode.

[0009] US2020 / 0203757 discloses a lithium secondary battery including a positive electrode, a negative electrode, and a separator and an electrolyte disposed between the electrodes. The negative electrode includes a negative electrode current collector and forms metallic lithium on the negative electrode current collector during charging.

[0010] US2016 / 0261000 discloses an anode - free rechargeable battery including an anode current collector, a cathode, and a separator placed between the anode current collector and the cathode. The battery further includes an electrolyte, which includes a salt or a mixture of salts containing active cations dissolved in a solvent or a solvent mixture. The active cations can be lithium, sodium, potassium, magnesium, calcium, zinc, aluminum, or silver. During the first charge cycle, a metallic layer of the cation is formed on the anode current collector.

[0011] The disadvantages of such anode-free batteries are that dendrites are prone to form, leading to short circuits and performance loss of battery cells. Another disadvantage includes the limited lifespan of such anode-free batteries, which, for example, includes a limited number of charge / discharge cycles.

[0012] US2022 / 166029 discloses an anode-free secondary battery having a cathode current collector, a cathode, an electrolyte, an optional separator, and an anode. The anode includes a conductive porous graphene foam and an anode current collector. The graphene foam maintains electrical contact with the anode current collector. Summary of the Invention

[0014] The object of the present invention is to overcome one or more of the aforementioned disadvantages. The object of the present invention is to provide an anode-free battery cell and an anode-free battery having a reduced risk of short circuit compared to the prior art anode-free battery cells and anode-free batteries.

[0015] Another object is to provide an anode-free battery cell and an anode-free battery having improved safety.

[0016] Another object is to provide an anode-free battery cell and an anode-free battery having excellent performance.

[0017] Another object is to provide an anode-free battery cell and an anode-free battery having an improved lifespan, for example, an anode-free battery cell and an anode-free battery that can withstand a higher number of charge / discharge cycles.

[0018] According to a first aspect of the present invention, there is provided an anode-free battery cell as described in the appended claims.

[0019] The anode-free battery cell includes a cathode current collector, a cathode, an electrolyte, and an electronic conductor provided on the anode side of the battery cell.

[0020] The cathode current collector can be any cathode current collector known in the art. For example, the cathode current collector can comprise aluminum or consist essentially of aluminum.

[0021] Advantageously, the cathode contains an active material. Advantageously, the active material comprises or consists essentially of one or more of an alkali metal, an alkaline earth metal, or a transition metal. Advantageously, the alkali metal is lithium or sodium. For example, the active material can comprise or consist essentially of an alkali metal, alkaline earth metal, or transition metal-based intercalation compound. Advantageously, the alkaline earth metal is magnesium. Advantageously, the transition metal is aluminum or zinc. Non-limiting examples of intercalation compounds include lithium iron phosphate (LFP) and sodium iron phosphate (NFP). Other non-limiting examples of active materials are lithium nickel cobalt aluminum oxide (NCA), lithium nickel cobalt manganese oxide (NMC), lithium manganese oxide (LMO), lithium nickel manganese oxide (LNMO), and lithium cobalt oxide (LCO).

[0022] Advantageously, the cathode further comprises an electronically conductive compound. The electronically conductive compound can be any conductive compound known in the art.

[0023] Advantageously, the cathode further comprises a binder. The binder can be any binder known in the art.

[0024] The electrolyte can be any type of electrolyte known in the art. Advantageously, the electrolyte is a solid (solid-state) electrolyte or a liquid electrolyte. When the electrolyte is a solid (solid-state) electrolyte, the electrolyte advantageously comprises a ceramic, a polymer, or a combination of two or more thereof. The electrolyte can be a non-aqueous electrolyte.

[0025] Advantageously and especially when the electrolyte is a liquid electrolyte, the anodeless battery cell further comprises a separator provided between the cathode and the high-surface area substrate, such as a separator membrane. The separator can be any separator known in the art.

[0026] The anodeless battery cell further comprises a high-surface area substrate. The high-surface area substrate is provided between the cathode and the electronic conductor.

[0027] At least a portion of the (first) surface of the high-surface area substrate contacts at least a portion of the surface of the electronic conductor.

[0028] Advantageously, at least a portion of the (second) surface of the high-surface area substrate contacts the electrolyte. Advantageously, the electronic conductor does not contact the electrolyte.

[0029] Advantageously, the electronic conductor comprises at least one metal or consists essentially of it. Advantageously, the metal is copper, a copper alloy, nickel, a nickel alloy, lithium, a lithium alloy, or steel. The steel can be stainless steel or carbon steel, but is not limited thereto. For example, the electronic conductor can comprise a nickel-plated copper foil.

[0030] Alternatively and alternatively or additionally, the electronic conductor comprises a polymer or consists essentially of it. Preferred examples of the polymer include poly(3,4-ethylenedioxythiophene) (PEDOT) and polyaniline, but are not limited thereto.

[0031] Alternatively and alternatively or additionally, the electronic conductor comprises carbon or consists essentially of carbon. Preferred examples of the carbon include carbon black, carbon nanotubes, graphite, or a combination of two or more thereof, but are not limited thereto.

[0032] Alternatively and alternatively or additionally, the electronic conductor comprises one or more of oxides, sulfides, nitrides, carbides, or silicides or consists essentially of them.

[0033] Non-limiting examples of the oxides include ruthenium oxide, iron oxide, manganese oxide, vanadium oxide, nickel oxide, copper oxide, and zinc oxide.

[0034] Non-limiting examples of sulfides include transition metal sulfides such as titanium sulfide (TiS2) and vanadium sulfides (VS and VS2).

[0035] Non-limiting examples of nitrides include titanium nitride and vanadium nitride.

[0036] Non-limiting examples of carbides include silicon carbide and transition metal carbides such as aluminum carbide and titanium carbide.

[0037] Non-limiting examples of silicides include aluminum silicide.

[0038] The terms "high surface area substrate" and "high surface area material" are used in the present disclosure to refer to substrates and materials having a porosity of at least 40% and / or a specific surface area of at least 25 m2 / g, where the porosity is measured by X-ray computed tomography.

[0039] Advantageously, the high surface area substrate has a porosity of at least 40%, preferably at least 45%, more preferably at least 50%, where the porosity is measured by X-ray computed tomography. "A porosity of at least 40%" means, according to the present disclosure, that the high surface area substrate has a porosity of at least 40% at each position or region of the substrate.

[0040] For example, the high surface area substrate may include a first region having a first porosity and at least a second region having a second porosity, where the first porosity and the second porosity are different and each is at least 40%. In addition, a substrate having a porosity of at least 40% is considered a porous substrate according to the present invention.

[0041] Advantageously, the high surface area substrate has a specific surface area of at least 25 m2 / g, preferably at least 30 m2 / g, for example at least 35 m 2 / g, at least 40 m 2 / g, at least 45 m 2 / g, more preferably at least 50 m 2 / g, most preferably at least 75 m2 / g. "A specific surface area of at least 25 m2 / g" means, according to the present disclosure, that the high surface area substrate has a specific surface area of at least 25 m2 / g at each position or region of the substrate.

[0042] For example, the high surface area substrate may include a first region having a first specific surface area value and at least a second region having a second specific surface area value, where the first specific surface area value and the second specific surface area value are different and each is at least 25 m2 / g.

[0043] Advantageously, the high-surface-area substrate comprises or consists essentially of a non-conductive, i.e. electrically insulating, compound. In other words, the high-surface-area substrate advantageously comprises a compound having a conductivity lower than 10 -6 (Ω·m) -1 , preferably lower than 10 -8 (Ω·m) -1 , more preferably lower than 10 -10 (Ω·m) -1 or consists essentially of such a compound.

[0044] Advantageously, the high-surface-area substrate comprises or consists essentially of an organic compound. Advantageously, the organic compound comprises or consists essentially of a polymer, i.e. is a polymer.

[0045] Advantageously, the polymer is selected from cellulose, regenerated cellulose (viscose), polypropylene, polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, polyurethane, aromatic polyamide and silk. Other examples of organic compounds include wool and polyaramide.

[0046] Advantageously and additionally or alternatively, the high-surface-area substrate comprises or consists essentially of an inorganic compound. Advantageously, the inorganic compound comprises lithium lanthanum zirconium oxide (LLZO) and / or a silica polymorph or consists essentially of such. Non-limiting examples of silica polymorphs include quartz, cristobalite, tridymite, coesite, stishovite, lechatelierite and opal.

[0047] Optionally, the high-surface-area substrate may further comprise a conductive particulate compound, i.e. a conductive compound comprising particles. The inventors have surprisingly found that, compared to a battery cell comprising a high-surface-area substrate without a particulate compound, by providing a conductive particulate compound within the high-surface-area substrate, in the use of an anode-free battery cell, the deposition of one or more of an alkali metal, an alkaline earth metal or a transition metal, including within the cathode active material, will be easier, e.g. faster, resulting in a conductivity high enough to render the battery cell operable. The inventors believe this is because the deposited metals (i.e. metals derived from ions of one or more of an alkali metal, an alkaline earth metal or a transition metal included within the cathode active material) are electrically connected to each other by means of the conductive particulate compound. In other words, less deposition of metal ions is required during use for the battery cell to exhibit a sufficiently high conductivity.

[0048] Advantageously, when the high-surface-area substrate comprises a conductive particulate compound, the particles are arranged or provided within the high-surface-area substrate such that the particles are electrically insulating. For example, the particles may be arranged such that each individual particle is physically insulated, i.e. does not contact other particles.

[0049] Advantageously, when the high-surface area substrate comprises a conductive particulate compound, the compound comprises a metal, an alloy of two or more metals, a carbon polymorph, or a combination of two or more thereof. Examples of carbon polymorphs are advantageously as described above and in particular are carbon nanotubes or graphene. Particular examples of alloys of two or more metals are intermetallic compounds.

[0050] Advantageously, when the high-surface area substrate comprises a conductive particulate compound, the particles have an average size of 1 nm - 1 mm, such as nanoparticles or microparticles. The particles may have a variable average size or average diameter.

[0051] The high-surface area substrate may have any shape or geometry or structure that provides a high surface area to the substrate. Advantageously, the high-surface area substrate is a film, foam, non-woven fabric, woven fabric or knitted fabric. Advantageously, the film and foam are open-cell films and foams.

[0052] Advantageously, the anode-free battery cell further comprises an anode lead extension. Advantageously, at least a portion of the surface of the anode lead extension contacts at least a portion of the surface of the electronic conductor. Advantageously, the anode lead extension does not contact the high-surface area substrate.

[0053] Advantageously, the anode lead extension comprises or consists essentially of at least one metal. Advantageously, the metal is copper, a copper alloy, nickel, a nickel alloy or steel. The steel may be stainless steel or carbon steel, but is not limited thereto. Advantageously, the anode lead extension does not comprise lithium or a lithium alloy.

[0054] Advantageously, the anode-free battery cell according to the present disclosure is a secondary battery.

[0055] According to a second aspect of the present invention, there is provided an anode-free battery as described in the appended claims. The anode-free battery comprises a stack of x anode-free battery cells according to the first aspect of the present invention, where x is from 2 to 20, preferably from 2 to 10, such as from 2 to 5.

[0056] Advantages of the anode-free battery cell and anode-free battery of the present disclosure include, but are not limited to, reduced formation of dendrites, which results in a reduced risk of short circuit. Accordingly, the battery cells and batteries of the present disclosure have an improved lifespan, i.e., they can withstand a higher number of charge / discharge cycles. BRIEF DESCRIPTION OF THE DRAWINGS

[0057] Aspects of the present invention will now be described in more detail with reference to the accompanying drawings, in which like reference numerals denote like features and in which:

[0058] - Figure 1 Schematically represents an anode-free battery cell according to the present disclosure;

[0059] -Figure 2 Schematically represent another anode-free cell unit according to the present disclosure; and

[0060] - Figure 3 Schematically represent yet another anode-free cell unit according to the present disclosure;

[0061] - Figure 4 Schematically represent an anode-free battery including a stack of anode-free cell units according to the present disclosure;

[0062] - Figure 5 Show the variation of voltage with respect to specific charge for several charge / discharge cycles of an anode-free cell unit according to the present disclosure;

[0063] - Figure 6 Show the variation of voltage with respect to specific charge for several charge / discharge cycles of a reference anode-free cell unit;

[0064] - Figure 7 Show the variation of voltage with respect to specific charge for several charge / discharge cycles of a reference lithium metal battery cell;

[0065] - Figure 8 Show the variation of voltage with respect to specific charge for the charge / discharge cycles of an anode-free cell unit, a reference anode-free cell unit, and a reference lithium metal battery cell according to the present disclosure;

[0066] - Figure 9 Show the variation of voltage with respect to specific charge for the second discharge cycle of an anode-free cell unit, a reference anode-free cell unit, and a reference lithium metal battery cell according to the present disclosure. Detailed Description of the Invention

[0068] Figure 1 Show the anode-free cell unit 100 according to the present disclosure. The cell unit 100 includes a cathode current collector 9, a cathode 1, and an electrolyte 2.

[0069] The cathode current collector 9 is advantageously as described above. Preferably, the cathode current collector 9 comprises aluminum or consists essentially of aluminum.

[0070] Advantageously and as is known in the art, the cathode current collector 9 extends from the anode-free battery 100. In other words, the cathode current collector 9 advantageously has a portion extending from a stack including a high-surface area substrate 4, an electrolyte 2, an optional separator 7, and a cathode 1. This can be achieved by methods known in the art, for example, by providing a cathode current collector 9 having a surface area greater than the surface area of the cathode 1. As is known, this extension allows for easy connection or coupling of the cathode current collector 9 to an electronic conductor 3 and also to an electronic circuit (not shown) to which it is advantageously connected or coupled.

[0071] The cathode 1 advantageously is as described above and comprises an active material, an electronically conductive material, and a binder.

[0072] The active material advantageously is as described above. Advantageously, the cathode comprises 25 - 99.7% by weight, such as 40 - 99.5% by weight, preferably 50 - 99% by weight, for example 60 - 97.5% by weight, more preferably 75 - 95% by weight of the active material based on the total weight of the cathode.

[0073] Advantageously, the electronically conductive material comprises a carbon-containing material, such as carbon fibers, carbon nanotubes, particulate carbon (e.g., powder), or a combination of two or more thereof. Advantageously, the electronically conductive material is a carbon-based electronically conductive material, such as graphite.

[0074] Advantageously, the cathode comprises 0.1 - 30% by weight, such as 0.25 - 25% by weight, preferably 0.5 - 20% by weight, for example 1 - 15% by weight, more preferably 2 - 10% by weight of the electronically conductive material based on the total weight of the electrode.

[0075] Advantageously, the binder comprises a rubber, such as styrene-butadiene rubber (SBR) or latex, polyvinylidene fluoride (PVDF), and polyvinylpyrrolidone (PVP), especially high molecular weight PVP, or consists essentially of the same.

[0076] Advantageously, the cathode comprises 0.1 - 30% by weight, such as 0.25 - 25% by weight, preferably 0.5 - 20% by weight, for example 0.75 - 15% by weight, more preferably 1 - 10% by weight of the binder based on the total weight of the cathode.

[0077] The anode-free battery cell 100 further comprises a high-surface-area substrate 4. The high-surface-area substrate 4 advantageously is provided on the side of the electrolyte 2 opposite to the cathode 1 side. The high-surface-area substrate 4 advantageously is as described above.

[0078] The high-surface-area substrate 4 can comprise a single layer or consist of a single layer, or can comprise multiple layers, i.e., two or more layers. When the high-surface-area substrate 4 comprises two or more layers, they can be the same or different. For example, they can have the same or different composition, structure, shape, thickness, or porosity. Advantageously, each layer has a porosity of at least 40%, where the porosity is measured by X-ray tomography technique, and / or a surface area of at least 25 m2 / g.

[0079] For example, the high-surface-area substrate 4 can comprise a first layer comprising or consisting essentially of an organic compound and a second layer comprising or consisting essentially of an inorganic compound. For example, the high-surface-area substrate 4 can comprise a first layer comprising or consisting essentially of cellulose or regenerated cellulose and a second layer comprising or consisting essentially of LLZO.

[0080] The anodeless battery cell 100 further includes an electronic conductor 3. At least a portion of the surface 6 of the electronic conductor 3 contacts at least a portion of the surface 5 of the high-surface area substrate 4.

[0081] Advantageously, the electronic conductor 3 extends from the anodeless battery cell 100. In other words, the electronic conductor 3 advantageously has a portion that extends from the stack including the high-surface area substrate 4, the electrolyte 2, the cathode 1, and the cathode current collector 9. This extension allows for easy connection or coupling of the electronic conductor 3 to the cathode current collector 9 and also advantageously to an electronic circuit (not shown) to which it is connected or coupled.

[0082] Advantageously, at least a portion of the surface 5 of the high-surface area substrate 4 that contacts the electronic conductor 3 is different from the surface of the high-surface area substrate 4 that contacts the electrolyte 2. This advantageously prevents short circuits.

[0083] Advantageously, the electronic conductor initiates metal deposition derived from metal ions from the cathode active material, i.e., ions of alkali metals, alkaline earth metals, or transition metals of the cathode active material. Advantageously, the electronic conductor further maintains the metal ion deposition of the active material. According to the present invention, initiating and / or maintaining the metal ion deposition of the active material is considered current conduction. By this principle of operation, an anode is formed in situ on and within the high-surface area substrate 4.

[0084] Advantageously, the metal ions are deposited on the surface of the high-surface area substrate 4. The inventors have found that by using the high-surface area substrate 4 according to the present disclosure instead of a bare anode current collector or a conventional anode (e.g., a metal layer (such as a lithium metal layer) connected to an anode current collector), the formation of dendrites is greatly reduced and even prevented. Therefore, the risk of short circuits within the battery cell is greatly reduced, thereby improving the safety and lifespan of the battery cell.

[0085] Figure 2 Another anodeless battery cell 101 is shown. The battery cell 101 advantageously includes a cathode current collector 9, a cathode 1, a high-surface area substrate 4, and an electronic conductor 3 as disclosed above for Figure 1 the battery cell 100.

[0086] The anodeless battery cell 101 further includes a separator 7. The separator 7 is used especially when the electrolyte is liquid. Advantageously, the separator 7 is a separator diaphragm, i.e., a battery separator diaphragm. The separator 7 can be a porous separator diaphragm.

[0087] Advantageously, the separator comprises or consists essentially of one or more polymers. Advantageously and alternatively or additionally, the battery separator diaphragm can be a ceramic material. For example, the separator can comprise a ceramic-loaded polymer.

[0088] Non-limiting examples of suitable polymers include polypropylene (PP), polyethylene (PE), polytetrafluoroethylene (PTFE), and polyvinylidene fluoride (PVDF). PP, PE, PTFE, and PVDF are preferred materials due to their chemically inert properties. However, they are not easily wetted, although a preferred porous separator can absorb the liquid electrolyte. For this reason, PP, PE, PTFE, and / or PVDF can be treated with surface treatment or coating, such as spraying, dip coating, or plasma coating—atmospheric plasma or low-pressure plasma.

[0089] The separator can include one or more layers. Of particular interest are multilayer separators, which are optionally ceramic-loaded three-layer PVDF-PE-PVDF separators.

[0090] Figure 3 Shown is yet another anodeless battery cell 102. The anodeless battery cell 102 includes, for example, a cathode current collector 9, a cathode 1, an electrolyte 2, a separator 7, a high-surface-area substrate 4, and an electronic conductor 3 as described above for Figure 2 the battery cell 101.

[0091] The battery cell 12 further includes an anode lead extension 8. The anode lead extension 8 is advantageously as described above. Advantageously, the anode lead extension 8 is capable of current collection.

[0092] The anode lead extension 8 is provided especially when the electronic conductor 3 contains lithium or consists essentially of it.

[0093] When the electronic conductor 3 does not contain lithium, it is preferred to optionally provide the anode lead extension 8. If provided, the anode lead extension 8 can have the same or a different composition from the lithium-free electronic conductor 3.

[0094] "Does not contain lithium" and "lithium-free" in this disclosure mean that the amount of lithium is below the detection limit of the analytical technique used to measure the amount of lithium present in a substrate or compound.

[0095] Figure 4 Schematically shown is an anodeless battery 103. The anodeless battery 103 includes a stack of two Figure 2 anodeless battery cells 101, where (adjacent) battery cells 101 share the cathode current collector 9. Examples

[0096] Two anodeless battery cells are provided: a reference anodeless battery cell and a battery cell according to the present disclosure. In addition, a reference battery cell including an anode is also provided.

[0097] All three battery cells include an aluminum cathode current collector. The aluminum cathode current collector has a surface area of 47.88 cm2.

[0098] The cathode of each cell unit contains 95 wt% NCA (CAS No. 193214-24-3) as the active material, 3 wt% PVDF binder, and 2 wt% carbon black as the electronic conductive compound based on the total weight of the cathode. The cathode is welded to an aluminum cathode current collector.

[0099] 7 g of electrolyte is used in each cell unit. The electrolyte contains 40 wt% lithium bis(fluorosulfonyl)imide (LiFSI), 30 wt% dimethoxyethane (DME) as the solvent, and 30 wt% 1,1,2,2-tetrafluoroethyl 2,2,3,3-tetrafluoropropyl ether (HFE-458, CAS No. 16627-68-2) based on the total weight of the electrolyte.

[0100] A three-layer ceramic-loaded PVDF-PE-PVDF separator diaphragm is also provided in each cell unit.

[0101] The cell unit according to the present disclosure includes a 14-μm-thick cellulose material as the high-surface-area substrate. The electronic conductor used is a 50-μm-thick lithium metal foil with a surface area of 4 cm2, which is much smaller than the surface area of the cathode current collector. A copper foil is used as the anode lead extension.

[0102] The anode-free reference cell unit includes a 6-μm-thick copper foil as the anode current collector. The copper foil has a surface area of 49 cm2, which is slightly larger than the surface area of the cathode current collector as is known in the art.

[0103] The reference cell unit including an anode includes a 25-μm lithium metal foil as the anode and a copper foil as the anode current collector. The lithium metal foil is welded to the copper foil as is known in the art. The surface area of the anode current collector is 49 cm2, which is slightly larger than the surface area of the cathode current collector as is known in the art.

[0104] Then the cell unit is charged and discharged, followed by two complete charge / discharge cycles at C / 10 (0.4 mA / cm 2 ) between 4.3 V and 3.0 V. The measurement results are shown in Figures 5-9 where the voltage (Y-axis) is shown as a function of specific charge (X-axis).

[0105] Figure 5 The results of the anode-free cell unit according to the present disclosure are shown, which represent the voltage (V) as a function of specific charge (expressed in Ah / kg). After the first charge represented by line 200, the cell unit is discharged (line 202). Line 201 shows the charge values in the subsequent two complete charge / discharge cycles and line 202 shows the discharge values. For the first and second complete charge / discharge cycles, it is noted that the charge and discharge values do not change significantly between the cycles.

[0106] Figure 6 Results of an anode-free reference cell are shown, which represent voltage (V) as a function of specific charge (expressed in Ah / kg). After the first charge represented by line 203, the cell is discharged (line 205). Line 204 shows the charge values in the subsequent two full charge / discharge cycles and line 205 shows the discharge values. For the first and second full charge / discharge cycles, it is noted that the charge and discharge values do not vary significantly between the cycles.

[0107] Figure 7 Results of a reference cell including an anode are shown, which represent voltage (V) as a function of specific charge (expressed in Ah / kg). In this cell, a lithium metal foil is laminated onto a copper foil. After the first charge represented by line 206, the cell is discharged (line 208). Line 207 shows the charge values in the subsequent two full charge / discharge cycles and line 208 shows the discharge values. For the first and second full charge / discharge cycles, it is noted that the charge and discharge values do not vary significantly between the cycles.

[0108] Figure 8 Results of the first full charge / discharge cycle of all three cells together are shown, which represents full utilization of the cathode of the cells. Figure 9 Results of the second discharge curve of all three anode-free cells together are shown.

[0109] As can be clearly seen from Figure 8 and 9 the cells of the present invention exhibit performance similar to that of the reference cells. However, the surface area of the electronic conductor used instead of the anode current collector of the reference cell is more than 10 times smaller. Thus, the amount of material required on the anode side of the cell is much lower, which results in a cheaper cell.

[0110] Nomenclature

[0111] 1. Cathode

[0112] 2. Electrolyte

[0113] 3. Electronic conductor

[0114] 4. High-surface-area substrate

[0115] 5. Surface of the high-surface-area substrate

[0116] 6. Surface of the electronic conductor

[0117] 7. Separator

[0118] 8. Anode lead extension

[0119] 9. Cathode current collector

[0120] 10. Cathode

[0121] 100. Anode - free cell unit

[0122] 101. Anode - free cell unit

[0123] 102. Anode - free cell unit

[0124] 103. Anode - free battery

[0125] 200. First charge - Anode - free cell unit 1

[0126] 201. Second and third charges - Anode - free cell unit 1

[0127] 202. First, second and third discharges - Anode - free cell unit 1

[0128] 203. First charge - Anode - free cell unit 2

[0129] 204. Second and third charges - Anode - free cell unit 2

[0130] 205. First, second and third discharges - Anode - free cell unit 2

[0131] 206. First charge - Anode - free cell unit 3

[0132] 207. Second and third charges - Anode - free cell unit 3

[0133] 208. First, second and third discharges - Anode - free cell unit 3

[0134] 209. Second discharge - Anode - free cell unit 1

[0135] 210. Second discharge - Anode - free cell unit 2

[0136] 211. Second discharge - Anode - free cell unit 3

Claims

1. An anode-free battery cell (100, 101, 102) comprising a cathode (1), an electrolyte (2), and an electronic conductor (3) provided on the anode side of the battery cell (100, 101, 102), characterized in that The battery cells (100, 101, 102) further include a high-surface-area substrate (4) provided between the cathode (1) and the electronic conductor (3), wherein at least a part of the surface (5) of the high-surface-area substrate (4) contacts at least a part of the surface (6) of the electronic conductor (3), wherein the porosity of the high-surface-area substrate (4) measured by X-ray computed tomography is at least 40%, and wherein the high-surface-area substrate (4) contains an organic compound and / or an inorganic compound containing lithium lanthanum zirconium oxide and / or silica polymorphs.

2. The anodeless battery cell (101, 102) according to claim 1, further including a separator (7) between the cathode (1) and the high-surface-area substrate (4).

3. An anode-free battery cell (100, 101, 102) according to any one of the preceding claims, wherein the high surface area substrate (4) has a specific surface area of at least 25 m 2 / g.

4. The anodeless battery cell (100, 101, 102) according to claim 3, wherein the high surface area substrate (4) has a specific surface area of at least 50 m 2 / g.

5. The anodeless battery cell (100, 101, 102) according to any one of the preceding claims, wherein the organic compound is a polymer.

6. The anodeless battery cell (100, 101, 102) according to claim 5, wherein the polymer is selected from cellulose, regenerated cellulose, polypropylene, polyethylene, polyvinylidene fluoride, polytetrafluoroethylene, polyurethane, aromatic polyamide, and silk.

7. An anode-free battery cell (100, 101, 102) according to any one of the preceding claims, wherein the high surface area substrate (4) has a conductivity of less than 10 -6 (Ω.m) -1 , preferably less than 10 -8 (Ω.m) -1 .

8. The anodeless battery cell (100, 101, 102) according to any one of the preceding claims, wherein the high-surface-area substrate (4) includes a first region having a first porosity and at least includes a second region having a second porosity, wherein the first porosity and the second porosity are different and are each at least 40% measured by X-ray computed tomography.

9. The anodeless battery cell (100, 101, 102) according to any one of the preceding claims, wherein the high-surface-area substrate (4) includes a conductive particulate compound.

10. The anodeless battery cell (100, 101, 102) according to claim 9, wherein the conductive particles of the compound are arranged within the high-surface-area substrate (4) such that they are electrically insulated from each other.

11. The anodeless battery cell (100, 101, 102) according to claim 9 or 10, wherein the conductive particulate compound contains a metal, an alloy of two or more metals, a carbon polymorph, or a combination of two or more thereof.

12. The anodeless battery cell (100, 101, 102) according to any one of the preceding claims, wherein the high-surface-area substrate (4) is a film, foam, nonwoven fabric, woven fabric, or knitted fabric.

13. The anodeless battery cell (100, 101, 102) according to any one of the preceding claims, wherein the electronic conductor (3) contains a metal, a polymer, a carbon polymorph, one or more of oxides, sulfides, nitrides, carbides, or silicides, or a combination of two or more thereof.

14. The anodeless battery cell (100, 101, 102) according to claim 13, wherein the metal is copper, nickel, lithium, or steel.

15. The anodeless battery cell (100, 101, 102) according to claim 13 or 14, wherein the polymer is poly(3,4-ethylenedioxythiophene) or polyaniline.

16. The anodeless battery cell (102) according to any one of the preceding claims, further comprising an anode lead extension (8), wherein at least a part of the surface of the anode lead extension (8) contacts at least a part of the surface of the electronic conductor (3).

17. The anodeless battery cell (102) according to claim 16, wherein the anode lead extension (8) comprises copper, nickel, steel, or a combination of two or more thereof.

18. The anodeless battery cell (100, 101, 102) according to any one of the preceding claims, wherein the battery cell (100, 101, 102) is a secondary battery.

19. An anodeless battery (103), comprising a stack of x anodeless battery cells (100, 101, 102) according to any one of the preceding claims, wherein x is from 2 to 20.

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