SOLID LAYER BATTERIES, AND THEIR PROCESS FOR PRODUCING THEM

Abstract

The present invention relates to a solid-layer battery and its method of production. (no figure)

Description

Title of the invention: SOLID FILM BATTERY, AND METHOD FOR OBTAINING SAME

[0001] The present invention relates to a solid-layer battery and a method for obtaining it.

[0002] Electronic components are found in many portable devices such as computers, mobile phones, tracking systems, optical readers, remote controls, etc. One of the disadvantages of these portable devices is the need to include a power supply. Portable devices generally use batteries as a power source. The batteries must have sufficient capacity to power the device for at least the duration of use of the device. Sufficient battery capacity may result in a power supply that is quite heavy and / or bulky compared to the rest of the device. Therefore, it is desirable to have smaller and lighter batteries that provide sufficient energy storage capacity.Other energy storage devices, such as supercapacitors, and energy conversion devices, such as photovoltaic cells and fuel cells, are alternatives to batteries for powering portable electronic devices or non-portable electrical applications, depending on the case. Another disadvantage of conventional batteries is that some are made from potentially toxic materials that can leak and are subject to government regulations. Therefore, there is a need to provide a safe source of electrical energy that can be recharged over many charge / discharge cycles.

[0003] In this context, a particular type of energy storage device has been developed: solid-state batteries, particularly thin-layer batteries.

[0004] A solid battery, also called a solid electrolyte battery or all-solid-state battery, refers to a type of electric accumulator for which the electrolyte, placed between the anode and the cathode, is solid, in the form of a glass plate, for example lithium phosphate, or gel.

[0005] This type of accumulator is seen as a replacement for lithium-ion accumulators, in particular due to a higher energy density, but also a higher operating temperature range: from -20 °C to more than 100 °C compared to 15 °C to 35 °C, as well as a lower risk of ignition or explosion. Indeed, in a battery, the positive ions move between the negative and positive electrodes via an ion conductor and deliver electrons to generate an electric current. In conventional batteries, for example lithium-ion batteries, the ionic conductor is a highly combustible liquid organic compound, which is a significant disadvantage.

[0006] Various research and development programs have synthesized a variety of compounds in order to find high-performance solid conductors to replace liquid electrolytes. In particular, researchers have discovered a solid-state ionic electrolyte whose performance exceeds that of a conventional lithium-ion electrolyte: LGPS solid sulfide electrolyte (LGPS: lithium, germanium, phosphorus, sulfur).

[0007] In the general context of battery electrodes, the available capacity, in particular the available capacity as a function of the supplied power, is an essential parameter for evaluating a device incorporating these electrodes, as well as the speed at which it is possible to charge and discharge the battery. It is well known in the literature that increasing the discharge / charge current of a battery reduces the capacity that the battery is capable of providing (Coulomb efficiency).

[0008] Conventionally, in order to overcome these drawbacks, the active material can be mixed with a good electronic conductor (such as carbon) or incorporated into a conductive matrix. In this case, the cathode material is incorporated into a carbon matrix. EP3809491 is an example of this approach. As shown in Figure 5 of this document, the carbon matrix reduces the capacity loss at a high current density.

[0009] The main limitation of this approach is the reduction of the total capacity: part of the volume is used for the conductive matrix, which does not offer any storage properties. Compared to a 100% active electrode, the capacity will be reduced. Furthermore, this approach is not easily applicable to solid-state thin-film batteries.

[0010] An objective of the invention is thus to provide batteries, in particular solid thin-film batteries, for which the loss of capacity during charge / discharge cycles is reduced or even absent.

[0011] Another objective of the invention is thus to make it possible to obtain such advantages, in particular during the first charge, on solid batteries, in particular thin layers of the LiCoO2 type.

[0012] Thus, the invention relates to a solid-layer battery, comprising an electronic and ionic conductive layer, separating an electrolyte layer and an electrode layer,

[0013] said electronic and ionic conductive layer constituting or forming part of the current collector of the electrode.

[0014] In particular, said current collector of the electrode comprises a first collector part being said electronic and ionic conductive layer, the electrode-electrolyte interface, as well as a second collector part located on one side of the electrode, as illustrated in [Fig.l].

[0015] By "separating the electrolyte layer and an electrode layer", it is meant in particular that the electronic and ionic conductive layer is in contact with both the electrolyte layer and an electrode layer, said electrolyte layer and electrode layer not being in contact with each other, or, in the case of a grid, in particular a metallic one, the electrolyte and the electrode are in contact via the holes in the grid.

[0016] According to a particular embodiment, the invention relates to a solid-layer battery, comprising an electronic and ionic conductive layer, separating an electrolyte layer from a cathode electrode layer,

[0017] said electronic and ionic conductive layer forming part of the current collector of the cathode.

[0018] [Fig.l] represents a battery according to the present invention.

[0019] According to a particular embodiment, the invention relates to a battery comprising:

[0020] - an anode current collector, in contact with an electrolyte layer;

[0021] - an electronic and ionic conductive layer, separating the electrolyte layer of a cathode electrode layer;

[0022] said electronic and ionic conductive layer forming part of the current collector of the cathode.

[0023] According to a particular embodiment, the invention relates to a battery comprising:

[0024] - an anode current collector, in contact with an electrode layer anodic;

[0025] - an electrolyte layer, in contact with the anodic electrode layer;

[0026] - an electronic and ionic conductive layer, separating the electrolyte layer of a cathode electrode layer;

[0027] said electronic and ionic conductive layer forming part of the current collector of the cathode.

[0028] By "separating the electrolyte layer from a cathode electrode layer" is meant in particular that the electronic and ionic conductive layer is in contact with both the electrolyte layer and the cathode electrode layer, said electrolyte layer and cathode electrode layer not being in contact with each other, or, in the case of a grid, in particular a metallic one, the electrolyte and the cathode are in contact via the holes in the grid. As part of the cathode current collector, said electronic and ionic conductive layer may be linked to the positive pole of the battery.

[0029] According to a particular embodiment, the invention relates to a solid-layer battery, comprising an electronic and ionic conductive layer, separating an electrolyte layer from an anodic electrode layer,

[0030] said electronic and ionic conductive layer forming part of the current collector of the anode.

[0031] The anode electrode may for example be an insertion anode electrode.

[0032] As part of the anode current collector, said electronic and ionic conductive layer can be linked to the negative pole of the battery.

[0033] The batteries of the invention are in particular fully solid layer batteries.

[0034] These are in particular solid thin-film batteries, more particularly all-solid thin-film batteries, which may also be referred to as solid thin-film batteries, more particularly all-solid thin-film batteries, respectively.

[0035] According to a particular embodiment, the electronic and ionic conductive layer has a thickness of 10 nm to 1 pm.

[0036] According to a particular embodiment, the cathode electrode layer has a thickness E of 1 pm to 200 pm.

[0037] According to a particular embodiment, the electronic and ionic conductive layer has a thickness of 10 nm to E / 2, E being the thickness of the cathode electrode layer as described above.

[0038] According to a particular embodiment, the invention relates to a thin-film battery in which:

[0039] - the anode current collector has a thickness of from 10 nm to 100 nm; and / or

[0040] - the anodic electrode layer has a thickness greater than 0 and less than or equal to at 8:00 pm; and / or

[0041] - the electrolyte layer has a thickness of from 10 nm to 100 nm.

[0042] - the cathode electrode layer has a thickness of from 1pm to 200pm.

[0043] - the electronic and ionic conductive layer has a thickness of between 20 nm and Ipm.

[0044] By "electronically conductive layer" is meant that the layer allows electrons to pass from the electrolyte layer to the cathode electrode layer, and from the cathode electrode layer to the electrolyte layer.

[0045] According to a particular embodiment, said electronic and ionic conductive layer has an electrical conductivity of at least 103 S.cm '. For example, the electrical conductivity may be from 103 to 108 S.cm '.

[0046] By "ionic conductive layer" is meant that the layer allows ions, in particular lithium, to pass from the electrolyte layer to the cathode electrode layer, and from the cathode electrode layer to the electrolyte layer.

[0047] According to a particular embodiment, said electronic and ionic conductive layer has an ionic conductivity of at least 106 S.cm. For example, the ionic conductivity may be from 108 to 102 S.cm.

[0048] According to a particular embodiment, said electronic and ionic conductive layer is made of or comprises at least one electronic and ionic conductive material.

[0049] According to a particular embodiment, said electronic and ionic conductive layer is made of or comprises a material M chosen from: - Metals possibly doped, in particular chosen from Si, Sn, Al, As, possibly doped, and their alloys; - Carbon-based materials, notably chosen from mesocarbon microbeads (MCMB), highly ordered pyrolytic graphite (HOPG), hard carbons, “soft” carbons; - LiTiO2 (corresponding to the state of TiO2 after insertion of lithium); and / or - LiFePO4.

[0050] The metals can be doped with B, As or P. The dopant is then present in particular at < 1% in the metal or in its alloys.

[0051] According to a particular embodiment, said electronic and ionic conductive layer contains the material M at a level of 95% to 100% by mass, more particularly M at a level of 100% by mass. By "at a level (...) by mass" is meant the percentage of the mass of the material M in the total mass of the electronic and ionic conductive layer.

[0052] According to a particular embodiment, said electrically and ionically conductive layer is made of or comprises at least one electronically conductive material and at least one ionically conductive material. A battery of the invention comprising such a layer is exemplified in [Fig.2].

[0053] According to a more particular embodiment, said electronic and ionic conductive layer is made of or comprises an electronic conductive material and an ionic conductive material.

[0054] Said electronically conductive material is in particular in the form of a grid.

[0055] By “grid” is meant in particular an openwork layer or plate, or an assembly of intersecting or parallel wires or bars.

[0056] The (at least one) electronically conductive material may be chosen from: - Metals, for example Pt, W, Al, Cu, Au, or Ti, in particular in the form of a grid.

[0057] The ionic conductive material is in particular an electrolyte, in particular a solid electrolyte. These electrolytes are well known in the literature.

[0058] The (at least one) ionic conductive material may be chosen from: - Solid electrolytes, in particular LiPON (lithium phosphorus oxynitride), LLTO (lithium lanthanum titanate), LLZO (Li7La3Zr2O12), LPS (lithium phosphorus sulfide), LTP (lithium titanium phosphate), LZP (lithium zirconium phosphate), LiSiON (lithium-silicon-oxynitride), LAGP (lithium aluminum germanium phosphate), LGPS (lithium germanium phosphorus sulfide), and optionally based on PEO (poly(ethylene oxide)), and in particular the solid electrolyte constituting or included in the electrolyte layer of the present battery of the invention.

[0059] The nature of the anode current collector, of the anode electrode layer, of the electrolyte layer, of the anode electrode layer, well known in the state of the art, can easily be determined by a person skilled in the art.

[0060] For example:

[0061] - the anode current collector is made of or comprises a selected material among Ti, Pt, Cu, Al, Au, W, TiN, doped Si, for example Ti;

[0062] - the anodic electrode layer is made of or comprises a selected material among Li, Al, C, In2O3, Si, SnO2, TiO2, V2O5, being for example Li;

[0063] - the electrolyte layer is made of or comprises a selected material among LiPON, LLTO, LLZO, LPS, LTP, LZP, LiSiON, LiN, LAGP, LGPS, based on PEO, being for example LiPON; and / or

[0064] - the cathode electrode layer is made of or comprises a selected material among LiCoO2, LiFePO4, LiMn2O4, LiNiO2, LiV3O8, LiMoO3, LiV2O5, NMC, being for example LiCoO2. As examples, methods for obtaining such layers are described in particular in Liu et al. (Advanced Materials, vol. 26, no. 37, pp. 6472-6477, 2014), Tadanaga et al. (Materials Research Bulletin, vol. 53, pp. 196-198, 2014), and Liu et al. (Electrochimica Acta, vol. 56, no. 3, pp. 1392-1398, 2011).

[0065] According to a particular embodiment, the anode and / or the cathode of the battery of the invention is (are) of the AAM (“Ail Active Material”) type.

[0066] By “AAM type” is meant in particular that the electrode is free of non-active additives.

[0067] By “devoid” is meant in particular that the electrode, in particular of the thin-film battery, contains less than 5%, or even less than 1%, relative to the total mass of the electrode, in mass of non-active additives.

[0068] According to a particular embodiment, the cathode electrode layer is furthermore in contact with a substrate.

[0069] The nature of the substrate, well known in the state of the art, can easily be determined by those skilled in the art.

[0070] The substrate is for example made of or comprises a material being SiO2 or Si.

[0071] According to a more particular embodiment, the substrate is conductive.

[0072] According to a particular embodiment, the solid layer battery comprises in a current collector element between the substrate and the electrode. In this case, this element is in particular part, just like the electronic and ionic conductive layer, of the current collector of the electrode.

[0073] According to a particular embodiment, the anode current collector layer is further in contact with a passivation layer.

[0074] The nature of this passivation layer, well known in the state of the art, can easily be determined by those skilled in the art.

[0075] The passivation layer is for example made of or comprises a material being parylene (PPX).

[0076] According to a more particular embodiment, the anode current collector layer is further in contact with a passivation layer, said anode current collector layer and passivation layer also being in contact with a redistribution layer (also known as a contact recovery layer or RDL).

[0077] The redistribution layer is for example made of or comprises a material being titanium.

[0078] Thus, a battery according to the invention comprises, for example, a stack in the order indicated below: - cathode electrode layer; - electronic and ionic conductive layer forming part of the cathode current collector; - electrolyte layer; and - anode current collector;

[0079] or a stack in the order indicated below: - cathode electrode layer; - electronic and ionic conductive layer forming part of the cathode current collector; - electrolyte layer; - anodic electrode layer; and - anode current collector;

[0080] or a stack in the order indicated below: - substrate; - cathode electrode layer; - electronic and ionic conductive layer forming part of the collector of

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[0093] cathode current; - electrolyte layer; - anodic electrode layer; and - anode current collector; or a stack in the order indicated below: - substrate; - cathode electrode layer; - electronic and ionic conductive layer forming part of the cathode current collector; - electrolyte layer; - anodic electrode layer; - anode current collector; and - passivation layer and redistribution layer. Other layers may be interposed between the cathode (cathode electrode layer) and the front collector (the electronic and ionic conductive layer forming part of the cathode's current collector), and / or between the front collector and the electrolyte (electrolyte layer). Such layers are illustrated in [Fig.3]. These layers are likely to contribute to the improvement of chemical (prevent chemical degradation) and physical (improve adhesion and homogeneity of the lithium flow) performance. Examples of such layers include: - C, In2O3, Li12Mno.eNio.2O2, A12O3, ZrO2, A1PO4 as described in Y. Lyu et al., Advanced Energy Materials, vol. 11, no. 2, p. 2000982, 2021; G. Hu, J. Cao, Z. Peng, Y. Cao, and K. Du, Electrochimica Acta, vol. 149, pp. 49-55, Dec. 2014. - Coating of LiCoO2 in powder form with Li4Ti50i2, Li2TiO3, TiO2 as described in Z. Li et al., J. Power Sources, vol. 541, p. 231703, Sept. 2022. - LTO, LLZO, LiTaO3, LiA102, LiNbO3, NASICON, etc. as described in A. Banerjee et al., Chem. Rev., vol. 120, no. 14, pp. 6878-6933, July 2020. The thickness of such layers is between 1nm and 50nm. According to another aspect, the invention also relates to a method for preparing a battery as defined above, which comprises a step of depositing the electronic and ionic conductive layer on the cathode electrode layer. This deposition can be carried out by techniques well known to those skilled in the art, in particular by thin film deposition techniques, for example, - by atomic layer epitaxy (atomic layer etching or ALE), - by atomic thin film deposition or ALD, - by depositing layers by evaporation,

[0094] - by deposition of layers by cathodic sputtering or sputtering,

[0095] - by depositing layers by electrodeposition.

[0096] The other elements of the battery can be put in place according to one of the techniques well known to those skilled in the art, described for example by {AC Kozen et al., Chem. Mater. 2015, 27, 15, 5324-5331; EMF Vieira et al., EMF Vieira et al., J. Phys. D: Appl. Phys., 2016, 49, 48, 5301 (; WO 2008019398A1}.

[0097] According to another aspect, the invention also relates to the use of a battery according to the invention, as a solid battery, in particular as an integrated solid microbattery, for powering an electrical device, in particular a portable device.

[0098] This device is for example a (bio)medical device, in particular an implantable (bio)medical device, or an electronic leisure device, in particular an augmented reality device. DEFINITIONS

[0099] As used herein, the value ranges in the form of "xy" or "from x to y" or "between x and y" include the bounds x and y, as well as the integers between these bounds. For example, "1-5", or "from 1 to 5" or "between 1 and 5" designates in particular the integers 1, 2, 3, 4 and 5. Preferred embodiments include each individual integer in the value range, as well as any subcombination of these integers. For example, preferred values ​​for "1-5" may include the integers 1, 2, 3, 4, 5, 1-2, 1-3, 1-4, 1-5, 2-3, 2-4, 2-5, etc.

[0100] As used herein, the term "about" refers to a range of values ​​within ± 10% of a specific value. For example, the term "about 20" includes values ​​of 20 ± 10%, or values ​​from 18 to 22.

[0101] For the purposes of this description, percentages refer to percentages by mass relative to the total mass of the formulation, unless otherwise indicated.

[0102] By layer, we mean in particular a stratum of superimposed or stacked elements. FIGURES

[0103] [Fig.l] illustrates a cross-sectional view of a battery being obtained according to the examples of the present application.

[0104] [Fig.2] illustrates a cross-sectional view of a battery being obtained according to the examples of the present application, in which the anode is shown.

[0105] [Fig. 3] illustrates a battery whose electronic and ionic conductive layer is made of or comprises an electronic conductive material (a metal grid, for example Pt) and an ionic conductive material (solid electrolyte, for example LiPON). A: cross-sectional view. B: top view of said layer.

[0106] [Fig.4] illustrates a cross-sectional view of a battery according to the invention comprising two stabilizing layers, one between the cathode (electrode layer cathode) and the front collector (the electronic and ionic conductive layer forming part of the cathode current collector), and the other between the front collector and the electrolyte (electrolyte layer). EXAMPLES

[0107] A solid thin-film battery according to the invention is prepared as follows.

[0108] A 100 nm thick amorphous TiO2 layer (cathode current collector) is deposited by ALD on a 20 pm thick LiCoO2 cathode layer. A LIPON type electrolyte layer (1 pm thick) and a Ti anode current collector are added to obtain the active part of the battery.

[0109] The other elements of the battery (support: SiO2, passivation layer: PPX, contact recovery layer: Ti), were put in place as known to those skilled in the art.

[0110] The capacity gain at ImA.cm2 is approximately + 0.4mA.cm2, i.e. a gain of +50% compared to the prior art (current collector placed under the cathode layer, which is also in contact with the electrolyte layer.

[0111] Furthermore, the capacity retention is much more stable: loss of only 10% between 0.1 and 10 mA.cm2 compared to 30% for the prior art.

[0112] [Fig. 1] illustrates an example of a battery that can thus be obtained.

Claims

Claims

1. A solid-state battery, comprising an electronically and ionically conductive layer separating an electrolyte layer and an electrode layer, said electronically and ionically conductive layer forming part of the current collector of the electrode.

2. Battery according to claim 1, comprising: - an anode current collector, in contact with an electrolyte layer; - an electronic and ionic conductive layer, separating the electrolyte layer from a cathode electrode layer; said electronic and ionic conductive layer being part of the cathode current collector.

3. Battery according to claim 1, comprising: - an anode current collector, in contact with an anode electrode layer; - an electrolyte layer, in contact with the anode electrode layer; - an electronic and ionic conductive layer, separating the electrolyte layer from a cathode electrode layer; said electronic and ionic conductive layer being part of the cathode current collector.

4. A battery according to any preceding claim, wherein the electronic and ionic conductive layer has a thickness of 10 nm to 1 pm.

5. A battery according to any preceding claim, wherein the cathode electrode layer has a thickness E of 1pm to 200pm.

6. A battery according to any preceding claim, wherein the electronic and ionic conductive layer has a thickness of 10 nm to E / 2, E being the thickness of the cathode electrode layer as described in claim 5.

7. Battery according to any one of the preceding claims, in which said electronic and ionic conductive layer comprises an electrical and ionic conductive material, chosen from: - Optionally doped metals, chosen from Si, Sn, Al, As, optionally doped, and their alloys; - Carbon-based materials, selected from mesocarbon microbeads (MCMB), highly ordered pyrolytic graphite (HOPG), hard carbons, soft carbons; - LiTiO2; and / or - LiFePO4.

8. Battery according to any one of claims 1 to 6, wherein said electronic and ionic conductive layer comprises at least one electronic conductive material and at least one ionic conductive material, the at least one electronic conductive material being chosen from the metals Pt, W, Al, Cu, Au, and Ti, in particular in the form of a grid, and / or the at least one ionic conductive material being chosen from the solid electrolytes LiPON, LLTO, LLZO, LPS, LTP, LZP, LiSiON, LAGP, LGPS, and optionally based on PEO, and the solid electrolyte constituting or included in the electrolyte layer as defined in claim 1.

9. A method of preparing a battery according to any one of claims 1 to 8, which comprises a step of depositing the electronic and ionic conductive layer on the cathode electrode layer.

10. Method according to claim 9, the deposition step is carried out by atomic layer epitaxy.

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