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 LAYER BATTERY, AND ITS METHOD FOR PRODUCING IT

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

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

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

[0004] A solid-state battery, also called a solid-state battery or all-solid-state battery, refers to a type of electrical accumulator in 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 battery is seen as a replacement for lithium-ion batteries, due in particular to its higher energy density, but also to a wider operating temperature range: from -20°C to over 100°C compared to 15°C to 35°C, as well as a lower risk of fire or explosion. Indeed, in a battery, positive ions move between the negative and positive electrodes via an ion conductor and release electrons to generate an electric current. In conventional batteries, for example lithium-ion batteries, the conductor Ionic is a highly combustible liquid organic compound, which is a significant disadvantage.

[0006] Various research and development programs have led to the synthesis of 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: the LGPS sulfide solid electrolyte (LGPS: lithium, germanium, phosphorus, sulfur).

[0007] In the general context of battery electrodes, the available capacity, particularly the available capacity as a function of the power supplied, is a key parameter for evaluating a device incorporating these electrodes, as is the rate at which the battery can be charged and discharged. It is well established 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, 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 capacitance loss at high current density.

[0009] The main limitation of this approach is the reduction in total capacity: part of the volume is used for the conductive matrix, which offers no 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] One objective of the invention is thus to provide batteries, in particular solid-state 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 therefore to enable such advantages to be obtained, particularly during the first charge, on solid batteries, particularly thin-film batteries of the LiCoO2 type.

[0012] Thus, the invention relates to a solid-layer battery, comprising an electronically and ionically 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 portion being said electronic and ionic conductive layer, at the electrode-electrolyte interface, as well as a second collector part located on one side of the electrode, as illustrated in [Fig.1].

[0015] By "separating the electrolyte layer and an electrode layer", it is understood in particular that the electronic and ionic conductive layer is in contact with both the electrolyte layer and an electrode layer, the 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 electronically and ionically 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. 1 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 electronically and ionically 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 electronically and ionically 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," it is understood in particular that the electronically and ionically conductive layer is in contact with both the electrolyte layer and the cathode electrode layer, the said electrolyte layer and cathode electrode layer not being in contact with each other, or, in the case of a grid, particularly 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 electronically and ionically conductive layer may be connected to the positive terminal of the battery.

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

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

[0031] The anodic electrode can, for example, be an insertion anodic electrode.

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

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

[0034] This refers in particular to solid thin film batteries, more particularly to fully solid thin film batteries, which can also be called solid thin film batteries, more particularly to fully solid thin film batteries, respectively.

[0035] According to a particular embodiment, the electronic and ionic conductive layer has a thickness of lOnm to Ipm.

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

[0037] According to a particular embodiment, the electronic and ionic conductive layer has a thickness of lOnm 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 between 100m and 100m; and / or

[0040] - the anodic electrode layer has a thickness greater than 0 and less than or equal to at 200pm; and / or

[0041] - the electrolyte layer has a thickness of between lOnm and lOpm.

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

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

[0044] By "electronic conductive layer", it is understood 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", it is understood 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 electronically and ionically conductive layer is made of or comprises at least one electronically and ionically conductive material.

[0049] According to a particular embodiment, said electronically and ionically conductive layer is made of or comprises a material M selected 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 lithium insertion); and / or - LiFePO4.

[0050] 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 material M in a quantity of 95% to 100% by mass, more particularly M in a quantity of 100% by mass. By "in a quantity of (...) by mass" is meant the percentage of the mass of 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 electronically conductive material and an ionically conductive material.

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

[0055] By "grid" is meant in particular a perforated layer or plate, or an assembly of interlaced 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, especially in grid form.

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

[0058] The (at least one) ionically 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 aluminium 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, the anodic electrode layer, the electrolyte layer, the anodic electrode layer, well known from 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 material selected among Ti, Pt, Cu, Al, Au, W, TiN, doped Si, for example Ti;

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

[0063] - the electrolyte layer is made of or comprises a material selected from 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 material selected among LiCoO2, LiFePO4, LiMn2O4, LiNiO2, LiV3O8, LiMoO3, LiV2O5, NMC, being for example LiCoO2. As examples, processes 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 cathode of the battery of the invention is (are) of type AAM (“Ail Active Material”).

[0066] By "AAM type", it is understood in particular that the electrode is free of inactive additives.

[0067] By “free of”, it is understood 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, by mass of inactive additives.

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

[0069] The nature of the substrate, well known from the state of the art, can easily be determined by a person 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, like the electronic and ionic conductive layer, forms part of the electrode's current collector.

[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 from the state of the art, can easily be determined by a person 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 the contact resumption 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 stacking in the order indicated below: - cathode electrode layer; - electronically and ionically conductive layer forming part of the collector cathode current; - electrolyte layer; - anodic electrode layer; and - anode current collector;

[0080] or a stacking 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; and - anode current collector;

[0081] or a stacking 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.

[0082] Other layers may be interposed between the cathode (cathodic electrode layer) and the front collector (the electronically and ionically conductive layer forming part of the cathode current collector), and / or between the front collector and the electrolyte (electrolyte layer). Such layers are illustrated in [Fig. 3].

[0083] These layers are likely to contribute to the improvement of chemical performance (preventing chemical degradation) and physical performance (improving adhesion and homogeneity of the lithium flow).

[0084] Examples of such layers include:

[0085] - 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, p. 49-55, Dec. 2014.

[0086] - Coating of LiCoO2 in powder form with Li4Ti5O2, Li2TiO3, TiO2 as described in Z. Li et al., J. Power Sources, vol. 541, p. 231703, Sept. 2022.

[0087] - LTO, LLZO, LiTaO3, LiA102, LiNbO3, NASICON, etc. as described in A. Banerjee et al., Chem. Rev., vol. 120, no. 14, p. 6878-6933, July 2020.

[0088] The thickness of such layers is between Inm and 50nm.

[0089] According to another aspect, the invention also relates to a method for preparing a battery as defined above, which includes a step of depositing the electronic and ionic conductive layer on the cathode electrode layer.

[0090] This deposition can be carried out using techniques well known to those skilled in the art, in particular thin-film deposition techniques, for example,

[0091] - by atomic layer epitaxy (atomic layer etching or ALE for "atomic layer etching"),

[0092] - by deposition of atomic thin films or ALD,

[0093] - by deposition of layers by evaporation,

[0094] - by depositing layers by cathodic sputtering,

[0095] - by electrodeposition of layers.

[0096] The other elements of the battery can be set up 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., 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 micro battery, to power an electrical device, in particular a portable one.

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

[0099] As understood here, 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" refers in particular to the integers 1, 2, 3, 4, and 5. Preferred embodiments include each integer taken individually 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 in this description, the term "approximately" refers to a range of values ​​within ±10% of a specific value. For example, the expression "approximately 20" includes values ​​within 20 ±10%, that is, 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 stated.

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

[0103] Fig. 1 illustrates a cross-sectional view of a battery being obtained according to the examples in this application.

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

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

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

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

[0108] A 100 nm thick layer of amorphous TiO2 (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 resumption layer: Ti), were put in place as known to the person skilled in the art.

[0110] The capacitance 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] In addition, the retention of capacity is much more stable: loss of only 10% between 0.1 and 10 mA.cm2 versus 30% for the previous art.

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

Claims

Demands

1. Solid-layer battery comprising: - an anode current collector, in contact with an electrolyte layer; - an electronically and ionically conductive layer, separating the electrolyte layer from a cathode electrode layer; said electronically and ionically conductive layer forming part of the cathode current collector.

2. Battery according to claim 1, wherein the electronic and ionic conductive layer has a thickness of lOnm to Ipm.

3. Battery according to any one of the preceding claims, wherein the cathode electrode layer has a thickness E of Ipm to 200pm.

4. Battery according to any one of the preceding claims, wherein the electronic and ionic conductive layer has a thickness of lOnm to E / 2, E being the thickness of the cathode electrode layer as described in claim 3.

5. Battery according to any one of the preceding claims, wherein said electronically and ionically conductive layer comprises an electrically and ionically conductive material, selected from: - Metals optionally doped, selected 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.

6. Battery according to any one of claims 1 to 4, wherein said electronically and ionically conductive layer comprises at least one electronically conductive material and at least one ionically conductive material, the at least one electronically conductive material being selected from the metals Pt, W, Al, Cu, Au, and Ti, in particular in grid form, and / or

7.

8. at least one ionically conductive material being chosen from among 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. Method for preparing a battery according to any one of claims 1 to 6, comprising a step of depositing the electronic and ionic conductive layer onto the cathode electrode layer. In the method according to claim 7, the deposition step is carried out by atomic layer epitaxy.

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