EP3545577A1 - Li-ion based electrochemical energy storage cell - Google Patents

Li-ion based electrochemical energy storage cell

Info

Publication number
EP3545577A1
EP3545577A1 EP17808385.3A EP17808385A EP3545577A1 EP 3545577 A1 EP3545577 A1 EP 3545577A1 EP 17808385 A EP17808385 A EP 17808385A EP 3545577 A1 EP3545577 A1 EP 3545577A1
Authority
EP
European Patent Office
Prior art keywords
layer
cathode
energy storage
current collector
anode
Prior art date
Legal status (The legal status is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the status listed.)
Withdrawn
Application number
EP17808385.3A
Other languages
German (de)
French (fr)
Inventor
Stephan Buecheler
Alejandro Nicolas FILIPPIN
Michael Rawlence
Current Assignee (The listed assignees may be inaccurate. Google has not performed a legal analysis and makes no representation or warranty as to the accuracy of the list.)
Eidgenoessische Materialprufungs und Forschungsanstalt EMPA
Original Assignee
Eidgenoessische Materialprufungs und Forschungsanstalt EMPA
Priority date (The priority date is an assumption and is not a legal conclusion. Google has not performed a legal analysis and makes no representation as to the accuracy of the date listed.)
Filing date
Publication date
Application filed by Eidgenoessische Materialprufungs und Forschungsanstalt EMPA filed Critical Eidgenoessische Materialprufungs und Forschungsanstalt EMPA
Publication of EP3545577A1 publication Critical patent/EP3545577A1/en
Withdrawn legal-status Critical Current

Links

Classifications

    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M4/00—Electrodes
    • H01M4/02—Electrodes composed of, or comprising, active material
    • H01M4/64—Carriers or collectors
    • H01M4/66—Selection of materials
    • H01M4/661—Metal or alloys, e.g. alloy coatings
    • H01M4/662—Alloys
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/056—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes
    • H01M10/0561—Accumulators with non-aqueous electrolyte characterised by the materials used as electrolytes, e.g. mixed inorganic/organic electrolytes the electrolyte being constituted of inorganic materials only
    • H01M10/0562—Solid materials
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M10/00—Secondary cells; Manufacture thereof
    • H01M10/05—Accumulators with non-aqueous electrolyte
    • H01M10/058—Construction or manufacture
    • H01M10/0585—Construction or manufacture of accumulators having only flat construction elements, i.e. flat positive electrodes, flat negative electrodes and flat separators
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M6/00—Primary cells; Manufacture thereof
    • H01M6/40—Printed batteries, e.g. thin film batteries
    • H—ELECTRICITY
    • H01—ELECTRIC ELEMENTS
    • H01M—PROCESSES OR MEANS, e.g. BATTERIES, FOR THE DIRECT CONVERSION OF CHEMICAL ENERGY INTO ELECTRICAL ENERGY
    • H01M2300/00—Electrolytes
    • H01M2300/0017—Non-aqueous electrolytes
    • H01M2300/0065—Solid electrolytes
    • H01M2300/0068—Solid electrolytes inorganic
    • H01M2300/0071—Oxides
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02E—REDUCTION OF GREENHOUSE GAS [GHG] EMISSIONS, RELATED TO ENERGY GENERATION, TRANSMISSION OR DISTRIBUTION
    • Y02E60/00—Enabling technologies; Technologies with a potential or indirect contribution to GHG emissions mitigation
    • Y02E60/10—Energy storage using batteries
    • Y—GENERAL TAGGING OF NEW TECHNOLOGICAL DEVELOPMENTS; GENERAL TAGGING OF CROSS-SECTIONAL TECHNOLOGIES SPANNING OVER SEVERAL SECTIONS OF THE IPC; TECHNICAL SUBJECTS COVERED BY FORMER USPC CROSS-REFERENCE ART COLLECTIONS [XRACs] AND DIGESTS
    • Y02—TECHNOLOGIES OR APPLICATIONS FOR MITIGATION OR ADAPTATION AGAINST CLIMATE CHANGE
    • Y02P—CLIMATE CHANGE MITIGATION TECHNOLOGIES IN THE PRODUCTION OR PROCESSING OF GOODS
    • Y02P70/00—Climate change mitigation technologies in the production process for final industrial or consumer products
    • Y02P70/50—Manufacturing or production processes characterised by the final manufactured product

Definitions

  • the present invention describes a multi-layered thin film Li-ion based electrochemical energy storage cell, according to the preamble of claim 1, a rechargeable thin-film Li-ion based solid state battery in form of a stack of a multiplicity of multi-layered thin film Li-ion based electrochemical energy storage cells and a method for production of a multi-layered thin film Li-ion based electrochemical energy storage cell, by in-situ deposition steps followed by annealing process steps at elevated temperatures.
  • Lithium-ion accumulators, secondary or rechargeable batteries or battery cells can be used for electrically powered vehicles, as well as in computer technology, in particular for notebooks, smartphones or tablets.
  • Lithium-ion battery cells have a positive cathode and a negative anode, sandwiching an electrolyte in between.
  • a cathode current collector and an anode current collector are placed in direct electrical contact with the cathode and the anode respectively.
  • Charged lithium ions can move between both electrodes, while the discharge process from anode to cathode takes place.
  • Thin film batteries comprising different substrates and metal or metal oxide cathode current collectors are disclosed with thicknesses of less than 3 micrometers.
  • EP2897203 a composite current collector for an energy storage device electrode is disclosed, comprising at least copper, aluminum, nickel, gold, silver, and alloys thereof with a thickness from 1 to 100 pm.
  • EP2738852 discloses a current collector for a bipolar lithium ion secondary battery, wherein the metal layer contains at least one metal material selected from the group consisting of aluminum, nickel, copper, iron, titanium, and an alloy, a metal carbide, a metal nitride and a metal oxide of these metals.
  • Cathode current collectors in conventional Li-ion battery technology and especially in solid state batteries are predominantly based on aluminum due to its low cost and electrochemical stability at high voltage, exhibiting minor electrochemical reactions in the 3.5-5 V vs Li+/Li range due to the formation of a passivation layer.
  • aluminum melts already at 660 °C, which is incompatible with state-of-the-art battery materials, such as the high-voltage cathode LiMnl .5Ni0.5O4 and LiCo02 that require up to 750 °C to crystallize fully or solid-state electrolytes like LLZO (Li 7 La3Zr 2 0i2) demanding equal temperatures for crystallization.
  • the manufacturing of the electrochemical energy storage cells is still problematic, due to the temperatures used while depositing different material layers.
  • the object of the present invention is to create a multi-layered Li- based solid state electrochemical energy storage cell, which can easily be produced in an in-situ production process, which can resist elevated temperatures of more than 700°C, showing a high lithium resistance and high electrical conductivity even after a heat treatment in air/oxygen. With the high preparation temperatures, the prepared layers of the multi-layered solid state electrochemical energy storage cell are stable against oxidation and reactions with lithium.
  • cathode current collectors of stainless steel, tungsten, nickel and chromium react/oxidize in the potential range 4-4.5 V vs Li+/Li or oxidize below 600 °C.
  • NixAI is electrochemically stable in the potential range 2-4.7 V vs Li+/Li, but shows, only in the first cycle, a minor reaction from 3.5-5 V vs Li/Li+ which we attributed to the formation of a passivation layer with the electrolyte.
  • Another object of the subject matter of the invention is to provide a manufacturing method for such multilayered Li-based solid state electrochemical energy storage cell and rechargeable Li-ion based batteries made of these multilayered Li-based solid state electrochemical energy storage cells.
  • Figure 1 shows a schematic sectional view of one embodiment of a multi-layer solid state Li-based electrochemical energy storage cell
  • Figure 2 shows a schematic sectional view of second embodiment of an electrochemical energy storage cell with an additional cathode interlayer and anode interlayer.
  • Figures 3 are showing schematic sectional views of the layer by layer production of a multi-layer solid state Li-based electrochemical energy storage cell according steps a) to e).
  • Figure 4 shows a schematic sectional view of a rechargeable Li-ion based battery, made of the aforementioned cells with and without an anode current collector.
  • the electrochemical solid state energy storage cell 0 comprises at least the following layers in subsequent order: a substrate layer 1, a cathode current collector layer 2, a cathode layer 3, a solid electrolyte layer 4, an anode layer 5 and an anode current collector layer 6. Aside from the substrate layer 1, the thicknesses of each layer 2, 3, 4, 5, 6 should be between 100 nm and 50 microns.
  • Current leads 7 and 7' are connected to the cathode current collector, layer 2, and the anode current collector, layer 6.
  • Solid state refers to the use of a solid electrolyte in layer 4, a promising new development which makes very thin, robust energy storage cells 0 possible.
  • solid electrolyte materials applicable as solid electrolyte layer 4 known.
  • Li 7 La 3 Zr 2 0i2 (LLZO), with thicknesses between 100 nm and 2 microns, in particular 500 nm.
  • (Li, La)(Ti, M)0 3 is the general formula for denoting the perovskite family of Li-ion conductor, where M denotes a rare metal oxide which might be present or absent (as in lanthanum lithium titanate) in the compound.
  • the substrate layer different metals and non-metals such as glass can be used .
  • stainless steel which is temperature resistant well above 700°C, in particular in form of a stainless steel foil.
  • the cathode current collector layer 2 has to be electrochemical stable, high temperature corrosion resistant at temperatures higher than 700 °C and resistant to reactions with lithium. We found, that a NixAI composition showed good results, leading to a simplified production method and showing desired oxidation resistance and lithium resistance.
  • the x lies between 0.3 and 9, in particular between 1 and 3. While the aluminium amount increases the oxidation resistance, the nickel amount increases the resistance against lithium.
  • NixAI alloys lithium resistance and the electrical conductivity after a heat treatment in air/oxygen (oxidizing atmosphere) of NixAI alloys is interesting . So far, the prior art did not mention these properties of NixAI alloys, when in contact with lithium containing layers. Therefore it was not obvious for the person skilled in the art, to restrict x between 1 and 3. An unusual try and extensive experiments were necessary to identify the x-range between 1 and 3.
  • the thickness of the cathode current collector layer 2 should lie between 50 nm and 5 microns, in particular 1 micron.
  • the NixAI composition regardless of the x range and substrate will be a conductive intermetallic compound in the form of a solid . Continuous films of NixAI less than 20-50 nm thickness could be grown by atomic layer deposition (ALD) by alternating layers of aluminum and nickel, followed by post annealing in vacuum or inert atmosphere. So, even forming islands, the cathode current collector layer 2 is working .
  • the physical and chemical properties of the NixAI are the essential properties related to the application of this intermetallic compound as current collector in thin film all-solid-state Li-ion batteries.
  • a third component can be added to the NixAI, in particular in form of an amount of chromium.
  • the composition of the cathode current collector layer 2 should comprise up to 30% weight of chromium. But amounts below 10% of chromium are desirable to limit the diffusion of this element into the cathode layer 3.
  • the missing layers 3, 4, 5, 6 will be deposited, which is at least partly associated with an annealing step after some deposition steps. These annealing steps at elevated temperatures up to 700°C and more, are harmful for cathode current collectors known from the prior art. But the above described cathode current collector layer 2 is resistant against the elevated temperatures.
  • NixAI thin film cathode current collector layers 2 are high temperature oxidation resistant above 1000 °C, electrochemically stable up to at least 4.5 V vs Li+/Li and lithium resistance at high temperatures at least up to 700 °C.
  • NixAI does not present any reaction with lithium when annealed for example with LiMnl .5Ni0.5O4 or Li20 at a temperature of 750 °C. Furthermore, above a 10% atomic percentage of Al in the superalloy, NixAI can effectively withstand annealing in oxygen at more than 1000 °C for long periods of time. Noble metals such as gold and platinum tend to alloy with lithium and have a prohibitive cost to be used in mass produced batteries.
  • the cathode layer 3 directly neighbouring the cathode current collector layer 2, is deposited subsequently onto the cathode current collector layer 2.
  • Lithium comprising material as LiMnl .5Ni0.5O4, LiCo0 2 , LiNii / 3Coi / 3Mni /3 0 2 , LiNiCoAI0 2 are among the suitable candidates.
  • the thickness of cathode layer 3 is between 100 nm and 50 microns.
  • an annealing step has to follow the deposition step of the cathode layer 3 unless deposition at elevated temperature is carried out.
  • the solid electrolyte layer 4 Directly connected to the cathode layer 3 is the solid electrolyte layer 4 as stated above.
  • the anode layer 5 may be made of silicon, lithium, LiTi 4 0 5 or aluminium, tin and/or alloys thereof and is also deposited onto the solid electrolyte layer 4.
  • the chosen thickness is in the order of the thickness of the cathode layer 3.
  • the anode current collector layer 6 is subsequently deposited onto the anode layer 5 and may be made from an electrically conductive material such as copper, titanium, nickel, gold, silver, platinum, molybdenum, manganese, metal alloys, conductive ceramics, conductive semiconductors and the like.
  • the thickness of the anode current collector layer 6 varies between 100 nm and 1 millimetre. The anode current collector layer 6 would not need to resist elevated temperatures.
  • Figure 2 shows an electrochemical energy storage cell 0' in the multi- layered setup as known from figure 1, wherein the same parts are marked with the same references. The differences are the arrangements of a cathode interlayer 34, between adjacent cathode layer 3 and solid electrolyte layer 4 and an anode interlayer 45 between solid electrolyte layer 4 and anode layer 5.
  • each interlayer 34, 45 should be between 10 nm to 50 nm.
  • the interlayers 34, 45 are comprising a Li- comprising compound, wherein the cathode interlayer 34 could comprise LiF, LiAIF 6 , Li 2 ZrF 6 , LiNb0 3 , while the anode interlayer 45 could comprise LiF, LiAIF 6 , Li 2 ZrF 6 , Li 3 N, Li 2 S.
  • FIG. 3a) to e) are showing the productions steps, beginning with providing a substrate layer 1.
  • the production method starts with the deposition of the cathode current collector layer 2, by any adequate technique, on any processable substrate layer 1, preferably of flexible nature, which is not restricted to conductive substrates but it would be desirable.
  • cathode current collector layer 2 Possible deposition techniques for the cathode current collector layer 2 are electron beam evaporation, thermal evaporation, atomic layer deposition, pulsed laser deposition, sputtering, thin-film printing . In particular electron beam evaporation or magnetron sputtering will be applied .
  • the reason for adding the cathode current collector layer 2 is to increase lithiation resistant and conductivity of the layers, after annealing in air/ oxygen in a later step, in particular, if such an annealing step of the solid electrolyte layer at or above 700°C is necessary.
  • the annealing step provides crystallization of the cathode layer 3.
  • the annealing step can be done by heating the setup up to 750 °C in oxygen atmosphere.
  • the annealing can also be done by photonic curing .
  • LiPON is a solid state electrolyte with a poor Lithium-ion conductivity around ⁇ 10 "6 S/cm, the solid state electrolyte we mention (LLZO) has a much higher and suitable ionic conductive ( ⁇ 10 ⁇ 3 S/cm).
  • anode material will be deposited forming the anode layer 5 onto the solid electrolyte layer 4.
  • another annealing step can be carried out.
  • the deposition of the anode current collector layer 6, for example copper or nickel, is performed, without an annealing step.
  • a rechargeable Li-ion based solid state battery 8 is producible by a stack of a multiplicity of in-situ prepared electrochemical energy storage cell 0, 0'. The concept of such a stacking of double layered cells in the field of thin film Li-ion based electrochemical energy storage cells 0', 0" is new.
  • a first electrochemical energy storage cell 0' comprising a substrate layer 1, a cathode current collector layer 2, a cathode layer 3, cathode interlayer 34, solid electrolyte layer 4, anode interlayer 45, anode layer 5 and anode current collector layer 6 are deposited and annealed as stated above.
  • a second electrochemical energy storage cell 0" is prepared in the same way, but without an anode current collector layer 6.
  • the second electrochemical energy storage cell 0" will be rotated and connected to the anode current collector layer 6 of the first electrochemical energy storage cell 0', such that the anode layer 5' of the second electrochemical energy storage cell 0" connects to the anode current collector layer 6 of the first electrochemical energy storage cell 0'.
  • Current leads 7, 7' can be connected to cathode current collector layers 2, 2' and the anode current collector layer 6.
  • a multiplicity of such thin-film solid state energy storage cells 0, 0', 0" is forming an electrochemical battery or rechargeable battery 8.
  • the electrochemical energy storage cells 0 or rechargeable batteries 8 can be used in a variety of application as stated above from hearing aids to electrically powered vehicles.
  • We show a novel cathode current collector layer 2 for next-generation bulk and thin film Li-ion batteries 8 based on a thin film of a Ni-AI superalloy with a composition in the range NixAI, x 0.3-9, deposited by magnetron sputtering at 300 °C in a low pressure argon atmosphere.
  • This cathode current collector shows a sufficient high temperature oxidation and lithium resistance and is electrochemically stable, for bulk and thin film Li-ion batteries.
  • state-of-the-art solid state electrolytes that require high temperatures such as the garnet Li7La3Zr2012 which requires at least 700 °C in oxygen atmosphere, can be directly deposited, annealed and electrically characterized to reach their proper crystallization.
  • NixAI thin film cathode current collector 2 By tuning the composition of NixAI thin film cathode current collector 2 to a richer nickel superalloy (x>2.9), the reaction between aluminium and the more mobile lithium of the solid electrolyte layer 4 at high temperatures can be avoided/minimized.
  • NixAI thin films Fabrication by magnetron sputtering and characterization of NixAI thin films with different compositions were carried out. Annealing experiments in the presence of other materials (LiMn l .5Ni0.5O4, Li7La3Zr2012, Li20) and under oxygen atmosphere were carried out along with electrochemical ones.
  • the thickness of the substrate layer 1 lies between 5 microns and 1 millimetre
  • the thickness of the solid electrolyte layer 4 lies between 100 nm and 2 microns
  • the thickness of the anode current collector layer 6 lies between lOOnm and 1 millimetre.

Abstract

The disclosed invention consists of a multi-layered thin film Li-ion based electrochemical energy storage cell, prepared in-situ in subsequent deposition processes, in which the subsequent deposited layers resist elevated temperatures of 700°C or higher. This is reached by a multi-layered thin film Li-ion based electrochemical energy storage cell, comprising a substrate layer, in form of a metal or non- metal compound temperature-resistant to at least 700°C and higher, a cathode current collector layer, comprising at least two metal elements, deposited directly onto the substrate layer, a cathode layer comprising a lithium compound, which crystallises at elevated temperatures at or above 700°C, a solid electrolyte layer comprising lithium, which crystallises at elevated temperatures at or above 700°C, an anode layer and an anode current collector layer.

Description

Li-ion based electrochemical energy storage cell
TECHNICAL FIELD
The present invention describes a multi-layered thin film Li-ion based electrochemical energy storage cell, according to the preamble of claim 1, a rechargeable thin-film Li-ion based solid state battery in form of a stack of a multiplicity of multi-layered thin film Li-ion based electrochemical energy storage cells and a method for production of a multi-layered thin film Li-ion based electrochemical energy storage cell, by in-situ deposition steps followed by annealing process steps at elevated temperatures.
STATE OF THE ART
In the field of electrochemical energy storage, research is concentrated on lithium-based batteries, since these currently have the largest available energy density with lowest weight, especially compared to nickel or lead-based accumulators. Lithium-ion accumulators, secondary or rechargeable batteries or battery cells can be used for electrically powered vehicles, as well as in computer technology, in particular for notebooks, smartphones or tablets.
Lithium-ion battery cells have a positive cathode and a negative anode, sandwiching an electrolyte in between. A cathode current collector and an anode current collector are placed in direct electrical contact with the cathode and the anode respectively. Charged lithium ions can move between both electrodes, while the discharge process from anode to cathode takes place.
To improve Li-ion batteries different approaches were chosen in the past, improving materials of electrodes and electrolytes. Especially foil like shapes of the components of Li-ion based cells were designed, leading to higher energy densities exhibiting an increased power-to- weight ratio, being ideal for commercial use in electric vehicles. The results were still bulky and these thin film Li-ion based batteries, still did not meet all requirements of the industry.
Different secondary batteries or rechargeable batteries with different layers in shape and materials were tried in the past. One possibility is disclosed in WO2014062676. Thin film batteries comprising different substrates and metal or metal oxide cathode current collectors are disclosed with thicknesses of less than 3 micrometers.
Recent efforts in the development of Li-ion based secondary batteries tried to find improved materials and sufficient shapes of the current collectors. In EP2897203 a composite current collector for an energy storage device electrode is disclosed, comprising at least copper, aluminum, nickel, gold, silver, and alloys thereof with a thickness from 1 to 100 pm. EP2738852 discloses a current collector for a bipolar lithium ion secondary battery, wherein the metal layer contains at least one metal material selected from the group consisting of aluminum, nickel, copper, iron, titanium, and an alloy, a metal carbide, a metal nitride and a metal oxide of these metals.
Regarding all-solid-state batteries there are still none ready for the market but the expectations around this technology are rather high. Bulk batteries would be preferred to thin film ones for applications demanding high to very high capacities, whereas for microelectronics and wearables thin films would be preferred .
Cathode current collectors in conventional Li-ion battery technology and especially in solid state batteries are predominantly based on aluminum due to its low cost and electrochemical stability at high voltage, exhibiting minor electrochemical reactions in the 3.5-5 V vs Li+/Li range due to the formation of a passivation layer. However, aluminum melts already at 660 °C, which is incompatible with state-of-the-art battery materials, such as the high-voltage cathode LiMnl .5Ni0.5O4 and LiCo02 that require up to 750 °C to crystallize fully or solid-state electrolytes like LLZO (Li7La3Zr20i2) demanding equal temperatures for crystallization. The manufacturing of the electrochemical energy storage cells is still problematic, due to the temperatures used while depositing different material layers.
DESCRIPTION OF THE INVENTION
The object of the present invention is to create a multi-layered Li- based solid state electrochemical energy storage cell, which can easily be produced in an in-situ production process, which can resist elevated temperatures of more than 700°C, showing a high lithium resistance and high electrical conductivity even after a heat treatment in air/oxygen. With the high preparation temperatures, the prepared layers of the multi-layered solid state electrochemical energy storage cell are stable against oxidation and reactions with lithium.
The elevated annealing temperatures are, for certain layers, necessary to reach crystallization. It was found that conventional cathode current collector weren't suitable due to the subsequent in-situ production, starting with a substrate and the cathode current collector. For example cathode current collectors of stainless steel, tungsten, nickel and chromium react/oxidize in the potential range 4-4.5 V vs Li+/Li or oxidize below 600 °C.
However, we have experimentally determined that NixAI is electrochemically stable in the potential range 2-4.7 V vs Li+/Li, but shows, only in the first cycle, a minor reaction from 3.5-5 V vs Li/Li+ which we attributed to the formation of a passivation layer with the electrolyte.
Another object of the subject matter of the invention is to provide a manufacturing method for such multilayered Li-based solid state electrochemical energy storage cell and rechargeable Li-ion based batteries made of these multilayered Li-based solid state electrochemical energy storage cells.
BRIEF DESCRIPTION OF THE DRAWINGS
The accompanying drawings, which are incorporated in and constitute a part of this application, illustrate several aspects of the invention and, together with a description of the embodiments, serve to explain the principles of the invention.
Figure 1 shows a schematic sectional view of one embodiment of a multi-layer solid state Li-based electrochemical energy storage cell, while
Figure 2 shows a schematic sectional view of second embodiment of an electrochemical energy storage cell with an additional cathode interlayer and anode interlayer. Figures 3 are showing schematic sectional views of the layer by layer production of a multi-layer solid state Li-based electrochemical energy storage cell according steps a) to e).
Figure 4 shows a schematic sectional view of a rechargeable Li-ion based battery, made of the aforementioned cells with and without an anode current collector.
The embodiments of the present invention described below are not intended to be exhaustive or to limit the invention to the precise forms disclosed in the following detailed description.
DESCRIPTION
We are describing a thin-film solid state energy storage device in form of an electrochemical solid state energy storage cell 0, in a multi- layered setup with a described ascending order of subsequent deposited layers. The total thickness of this electrochemical solid state energy storage cell 0 is about a few tens of microns.
The electrochemical solid state energy storage cell 0 comprises at least the following layers in subsequent order: a substrate layer 1, a cathode current collector layer 2, a cathode layer 3, a solid electrolyte layer 4, an anode layer 5 and an anode current collector layer 6. Aside from the substrate layer 1, the thicknesses of each layer 2, 3, 4, 5, 6 should be between 100 nm and 50 microns. Current leads 7 and 7' are connected to the cathode current collector, layer 2, and the anode current collector, layer 6.
Solid state refers to the use of a solid electrolyte in layer 4, a promising new development which makes very thin, robust energy storage cells 0 possible. There are some solid electrolyte materials applicable as solid electrolyte layer 4 known. We could reach good results with Li7La3Zr20i2 (LLZO), with thicknesses between 100 nm and 2 microns, in particular 500 nm. (Li, La)(Ti, M)03 is the general formula for denoting the perovskite family of Li-ion conductor, where M denotes a rare metal oxide which might be present or absent (as in lanthanum lithium titanate) in the compound.
For the substrate layer 1, different metals and non-metals such as glass can be used . In our experiments we used stainless steel, which is temperature resistant well above 700°C, in particular in form of a stainless steel foil.
The cathode current collector layer 2 has to be electrochemical stable, high temperature corrosion resistant at temperatures higher than 700 °C and resistant to reactions with lithium. We found, that a NixAI composition showed good results, leading to a simplified production method and showing desired oxidation resistance and lithium resistance. The x lies between 0.3 and 9, in particular between 1 and 3. While the aluminium amount increases the oxidation resistance, the nickel amount increases the resistance against lithium.
Here the lithium resistance and the electrical conductivity after a heat treatment in air/oxygen (oxidizing atmosphere) of NixAI alloys is interesting . So far, the prior art did not mention these properties of NixAI alloys, when in contact with lithium containing layers. Therefore it was not obvious for the person skilled in the art, to restrict x between 1 and 3. An unusual try and extensive experiments were necessary to identify the x-range between 1 and 3.
According to our experimental determinations we have found that below 50 nm of the cathode current collector layer 2 the conductivity decreases quite sharply in agreement with the formation of islands, whereas above 1 micron the conductivity can be considered as the bulk value. The thickness of the cathode current collector layer 2 should lie between 50 nm and 5 microns, in particular 1 micron. The NixAI composition regardless of the x range and substrate will be a conductive intermetallic compound in the form of a solid . Continuous films of NixAI less than 20-50 nm thickness could be grown by atomic layer deposition (ALD) by alternating layers of aluminum and nickel, followed by post annealing in vacuum or inert atmosphere. So, even forming islands, the cathode current collector layer 2 is working . The physical and chemical properties of the NixAI are the essential properties related to the application of this intermetallic compound as current collector in thin film all-solid-state Li-ion batteries.
To tune the effect of the cathode current collector layer 2, a third component can be added to the NixAI, in particular in form of an amount of chromium. The composition of the cathode current collector layer 2 should comprise up to 30% weight of chromium. But amounts below 10% of chromium are desirable to limit the diffusion of this element into the cathode layer 3. After deposition of the cathode current collector layer 2, the missing layers 3, 4, 5, 6 will be deposited, which is at least partly associated with an annealing step after some deposition steps. These annealing steps at elevated temperatures up to 700°C and more, are harmful for cathode current collectors known from the prior art. But the above described cathode current collector layer 2 is resistant against the elevated temperatures.
The NixAI thin film cathode current collector layers 2 are high temperature oxidation resistant above 1000 °C, electrochemically stable up to at least 4.5 V vs Li+/Li and lithium resistance at high temperatures at least up to 700 °C.
We have found that NixAI does not present any reaction with lithium when annealed for example with LiMnl .5Ni0.5O4 or Li20 at a temperature of 750 °C. Furthermore, above a 10% atomic percentage of Al in the superalloy, NixAI can effectively withstand annealing in oxygen at more than 1000 °C for long periods of time. Noble metals such as gold and platinum tend to alloy with lithium and have a prohibitive cost to be used in mass produced batteries.
The cathode layer 3, directly neighbouring the cathode current collector layer 2, is deposited subsequently onto the cathode current collector layer 2. Lithium comprising material as LiMnl .5Ni0.5O4, LiCo02, LiNii/3Coi/3Mni/302, LiNiCoAI02 are among the suitable candidates. The thickness of cathode layer 3 is between 100 nm and 50 microns. For crystallization of the cathode layer 3 an annealing step has to follow the deposition step of the cathode layer 3 unless deposition at elevated temperature is carried out. Directly connected to the cathode layer 3 is the solid electrolyte layer 4 as stated above. To allow crystallization of the solid electrolyte layer 4, also here an annealing step following the deposition step is necessary unless deposition at elevated temperature is carried out. Due to the fact, that all previous deposited materials are temperature resistant, the production method ensures faultless layer production.
The anode layer 5 may be made of silicon, lithium, LiTi405 or aluminium, tin and/or alloys thereof and is also deposited onto the solid electrolyte layer 4. The chosen thickness is in the order of the thickness of the cathode layer 3.
Also the anode current collector layer 6 is subsequently deposited onto the anode layer 5 and may be made from an electrically conductive material such as copper, titanium, nickel, gold, silver, platinum, molybdenum, manganese, metal alloys, conductive ceramics, conductive semiconductors and the like. The thickness of the anode current collector layer 6 varies between 100 nm and 1 millimetre. The anode current collector layer 6 would not need to resist elevated temperatures.
Figure 2 shows an electrochemical energy storage cell 0' in the multi- layered setup as known from figure 1, wherein the same parts are marked with the same references. The differences are the arrangements of a cathode interlayer 34, between adjacent cathode layer 3 and solid electrolyte layer 4 and an anode interlayer 45 between solid electrolyte layer 4 and anode layer 5.
Due to the interlayers 34, 45 the proposed electrochemical energy storage cell 0 shows higher performance and allows the use of high voltage cathodes or lithium metal as high capacity anode, therefore they are vital components of the electrochemical energy storage cell 0. The suitable thickness of each interlayer 34, 45 should be between 10 nm to 50 nm. In particular the interlayers 34, 45 are comprising a Li- comprising compound, wherein the cathode interlayer 34 could comprise LiF, LiAIF6, Li2ZrF6, LiNb03, while the anode interlayer 45 could comprise LiF, LiAIF6, Li2ZrF6, Li3N, Li2S.
Due to the novel cathode current collector layer 2 a direct deposition and annealing treatment of the subsequent layers 3, 4 and interlayers 34, 45 in a cell/battery onto the cathode current collector layer 2 is possible. In addition, the deposition technique of the NixAI thin film has already proven to be industrially scalable and a cost-effective solution for large scale production. Figure 3a) to e) are showing the productions steps, beginning with providing a substrate layer 1. The production method starts with the deposition of the cathode current collector layer 2, by any adequate technique, on any processable substrate layer 1, preferably of flexible nature, which is not restricted to conductive substrates but it would be desirable.
Possible deposition techniques for the cathode current collector layer 2 are electron beam evaporation, thermal evaporation, atomic layer deposition, pulsed laser deposition, sputtering, thin-film printing . In particular electron beam evaporation or magnetron sputtering will be applied . The reason for adding the cathode current collector layer 2 is to increase lithiation resistant and conductivity of the layers, after annealing in air/ oxygen in a later step, in particular, if such an annealing step of the solid electrolyte layer at or above 700°C is necessary.
This is followed by a deposition of the cathode material forming the cathode layer 3 onto the cathode current collector layer 2 followed by an annealing step at elevated temperatures or a photo curing step marked with "+T" in figure 3b). The annealing step provides crystallization of the cathode layer 3. The annealing step can be done by heating the setup up to 750 °C in oxygen atmosphere. The annealing can also be done by photonic curing .
For example LiPON is a solid state electrolyte with a poor Lithium-ion conductivity around ~10"6 S/cm, the solid state electrolyte we mention (LLZO) has a much higher and suitable ionic conductive (~10~3 S/cm).
Subsequently deposition of the solid-state electrolyte material forming the solid electrolyte layer 4 on the cathode layer 3, followed by another annealing step up to 750 °C in oxygen atmosphere. Deposition and annealing might be simultaneous.
After the crystallization of the solid electrolyte layer 4 is done, anode material will be deposited forming the anode layer 5 onto the solid electrolyte layer 4. Optionally another annealing step can be carried out.
Before finally the deposition of the anode current collector layer 6, for example copper or nickel, is performed, without an annealing step.
For commercially reasons a roll-to-roll manufacturing will help to increase the product output and bring costs down. After layerwise production by deposition and annealing steps, the current leads 7, 7' can be connected to the cathode current collector layer 2 and the anode current collector layer 6, for example with known welding processes. A rechargeable Li-ion based solid state battery 8 is producible by a stack of a multiplicity of in-situ prepared electrochemical energy storage cell 0, 0'. The concept of such a stacking of double layered cells in the field of thin film Li-ion based electrochemical energy storage cells 0', 0" is new. Our stack is due to the chosen materials compatible with LiPON, lithium phosphorus oxynitride, an amorphous glassy material used as an electrolyte material in thin film flexible batteries. As marked in figure 4 a first electrochemical energy storage cell 0', comprising a substrate layer 1, a cathode current collector layer 2, a cathode layer 3, cathode interlayer 34, solid electrolyte layer 4, anode interlayer 45, anode layer 5 and anode current collector layer 6 are deposited and annealed as stated above. A second electrochemical energy storage cell 0" is prepared in the same way, but without an anode current collector layer 6. The second electrochemical energy storage cell 0" will be rotated and connected to the anode current collector layer 6 of the first electrochemical energy storage cell 0', such that the anode layer 5' of the second electrochemical energy storage cell 0" connects to the anode current collector layer 6 of the first electrochemical energy storage cell 0'. Current leads 7, 7' can be connected to cathode current collector layers 2, 2' and the anode current collector layer 6.
A multiplicity of such thin-film solid state energy storage cells 0, 0', 0" is forming an electrochemical battery or rechargeable battery 8. The electrochemical energy storage cells 0 or rechargeable batteries 8 can be used in a variety of application as stated above from hearing aids to electrically powered vehicles. We show a novel cathode current collector layer 2 for next-generation bulk and thin film Li-ion batteries 8 based on a thin film of a Ni-AI superalloy with a composition in the range NixAI, x=0.3-9, deposited by magnetron sputtering at 300 °C in a low pressure argon atmosphere.
This cathode current collector shows a sufficient high temperature oxidation and lithium resistance and is electrochemically stable, for bulk and thin film Li-ion batteries. Onto the shown cathode current collector layer 2, state-of-the-art solid state electrolytes, that require high temperatures such as the garnet Li7La3Zr2012 which requires at least 700 °C in oxygen atmosphere, can be directly deposited, annealed and electrically characterized to reach their proper crystallization.
By tuning the composition of NixAI thin film cathode current collector 2 to a richer nickel superalloy (x>2.9), the reaction between aluminium and the more mobile lithium of the solid electrolyte layer 4 at high temperatures can be avoided/minimized.
Fabrication by magnetron sputtering and characterization of NixAI thin films with different compositions were carried out. Annealing experiments in the presence of other materials (LiMn l .5Ni0.5O4, Li7La3Zr2012, Li20) and under oxygen atmosphere were carried out along with electrochemical ones.
To reach small and highly compact electrochemical energy storage cells 0, the thickness of the substrate layer 1 lies between 5 microns and 1 millimetre, the thickness of the solid electrolyte layer 4 lies between 100 nm and 2 microns and the thickness of the anode current collector layer 6 lies between lOOnm and 1 millimetre.
LIST OF REFERENCE NUMERALS
0 electrochemical energy storage cell (Multi-layered, thin film, Li-ion based)
1 substrate layer
2 cathode current collector layer
3 cathode layer
34 cathode interlayer
4 solid electrolyte layer
45 anode interlayer
5 anode layer
6 anode current collector layer
7, T current leads
8 rechargeable Li-ion based solid state battery

Claims

PATENT CLAIMS
1. Multi-layered thin film Li-ion based electrochemical energy
storage cell (0), prepared in-situ in subsequent deposition processes,
comprising in ascending order:
a substrate layer (1), in form of a metal or non-metal compound temperature-resistant to 700°C and higher,
a cathode current collector layer, comprising at least two metal elements deposited directly onto the substrate layer (1), a cathode layer (3) comprising a lithium compound, which crystallises at or above elevated temperatures of 700°C, a solid electrolyte layer (4) comprising lithium, which crystallises at or above elevated temperatures of 700°C,
an anode layer (5) and
an anode current collector layer (6),
characterized in that the cathode current collector layer (2) comprises an electrically conductive composition of NixAI, wherein x lies between 1 and 3, with a thickness between 50 nm and 5 microns deposited onto the substrate layer (1).
Multi-layered thin film Li-ion based electrochemical energy storage cell according to claim 1, wherein the cathode current collector layer (2) comprises in addition to NixAI up to 30% weight of chromium, in particular below 10% weight of chromium.
Multi-layered thin film Li-ion based electrochemical energy storage cell according to one of the preceding claims, wherein between cathode layer (3) and solid electrolyte layer (4) a cathode interlayer (34) with a thickness between 10 nm and 50 nm and between solid electrolyte layer (4) and anode layer (5) an anode interlayer (45) with a thickness between 10 nm and 50 nm is placed .
4. Multi-layered thin film Li-ion based electrochemical energy storage cell according to claim 3, wherein the cathode interlayer (34) comprises LiF, LiAIF6, Li2ZrF6 or LiNb03 and the anode interlayer (45) comprises LiF, LiAIF6, Li2ZrF6, Li3N or Li2S.
5. Multi-layered thin film Li-ion based electrochemical energy
storage cell according to one of the preceding claims, wherein the thickness of the substrate layer (1) lies between 5 microns and 1 millimetre, the thickness of the solid electrolyte layer (4) lies between 100 nm and 2 microns and the thickness of the anode current collector layer (6) lies between lOOnm and 1 millimetre.
6. Multi-layered thin film Li-ion based electrochemical energy
storage cell according to one of the preceding claims,
wherein
the cathode layer (3) comprises ϋΜηι.5Ι\Μ0.5Ο4, LiCo02,
LiNii/3Coi/3Mni/302 or LiNiCoAI02,
the solid electrolyte layer (4) comprises Li7La3Zr20i2 (LLZO), LaTi03 , LiTi03 ,(Li, La)(Ti, M)03 (M = rare metal oxide),
LiMn1.5Ni0.5O4, or Li20
and the anode layer (5) comprises silicon, lithium, LiTi405, aluminium, tin and/or alloys thereof. 7. Rechargeable thin-film Li-ion based solid state battery (8) in form of a stack of a multiplicity of multi-layered thin film Li-ion based electrochemical energy storage cells (0', 0") according to one of the preceding claims, wherein at the anode current collector layer (6) of a first multi-layered thin film Li-ion based electrochemical energy storage cell (0') a second in-situ produced multi-layered thin film Li-ion based electrochemical energy storage cell (0") without an anode current collector layer (6) is rotated and connected with its anode layer (5') at the anode current collector layer (6) of the first multi-layered thin film Li-ion based electrochemical energy storage cell (0').
Rechargeable thin-film Li-ion based solid state battery (8) according to claim 7, wherein cathode interlayer (34) and/or anode interlayer (45) building part of first and second cells (0', 0").
Method for production of a multi-layered thin film Li-ion based electrochemical energy storage cell (0, 0', 0"), by in-situ deposition steps followed by annealing process steps at elevated temperatures,
comprising the steps of:
- providing a substrate layer (1),
- deposition of a cathode current collector layer (2), comprising an electrically conductive composition of NixAI, wherein x lies between 1 and 3, deposited directly onto the substrate layer (1), followed by
- deposition of a cathode layer (3) onto the cathode current collector layer (2) and a subsequent
- annealing step of the cathode layer (3) at elevated
temperatures at or above 700°C for crystallization of the cathode layer (3) material, before
- deposition of a cathode interlayer (34) onto the cathode layer (3) and subsequent
- deposition of a solid electrolyte layer (4) and
- an annealing step at elevated temperatures at or above 700°C for crystallization of the solid electrolyte layer (4) is carried out, followed by
- deposition of an anode interlayer (45) onto the electrolyte layer (4), before
- deposition of an anode layer (5),
and
- deposition of an anode current collector layer (6), before
- current leads (7, 7') are connected at the cathode layer (3) and anode layer (5).
10. Method for production of a multi-layered thin film Li-ion based electrochemical energy storage cell (0, 0', 0") according to claim 11, wherein the in-situ deposition steps are carried out by thermal evaporation, atomic layer deposition, pulsed layer deposition, sputtering or thin-film printing.
11. Method for production of a multi-layered thin film Li-ion based electrochemical energy storage cell (0, 0', 0") according to claim 11, wherein the in-situ deposition steps are carried out by electron beam evaporation or magnetron sputtering, followed by subsequent or simultaneous annealing under oxygen
atmosphere.
EP17808385.3A 2016-11-23 2017-11-20 Li-ion based electrochemical energy storage cell Withdrawn EP3545577A1 (en)

Applications Claiming Priority (2)

Application Number Priority Date Filing Date Title
EP16200316.4A EP3327837A1 (en) 2016-11-23 2016-11-23 Li-ion based electrochemical energy storage cell
PCT/EP2017/079730 WO2018095845A1 (en) 2016-11-23 2017-11-20 Li-ion based electrochemical energy storage cell

Publications (1)

Publication Number Publication Date
EP3545577A1 true EP3545577A1 (en) 2019-10-02

Family

ID=57391905

Family Applications (2)

Application Number Title Priority Date Filing Date
EP16200316.4A Withdrawn EP3327837A1 (en) 2016-11-23 2016-11-23 Li-ion based electrochemical energy storage cell
EP17808385.3A Withdrawn EP3545577A1 (en) 2016-11-23 2017-11-20 Li-ion based electrochemical energy storage cell

Family Applications Before (1)

Application Number Title Priority Date Filing Date
EP16200316.4A Withdrawn EP3327837A1 (en) 2016-11-23 2016-11-23 Li-ion based electrochemical energy storage cell

Country Status (2)

Country Link
EP (2) EP3327837A1 (en)
WO (1) WO2018095845A1 (en)

Families Citing this family (6)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
EP4293940A3 (en) 2017-05-12 2024-02-14 Koninklijke Philips N.V. Receiver, transmitter, communication network, data signal and method improving a retransmission process in a communication network
CN108550907B (en) * 2018-06-05 2020-08-21 北京卫蓝新能源科技有限公司 In-situ composite solid electrolyte and application thereof, all-solid-state battery and preparation method thereof
EP3863026B1 (en) * 2018-10-01 2022-06-15 Panasonic Intellectual Property Management Co., Ltd. Halide solid electrolyte material and battery using same
JPWO2020070956A1 (en) * 2018-10-01 2021-09-16 パナソニックＩｐマネジメント株式会社 Halide solid electrolyte material and batteries using it
WO2020070957A1 (en) * 2018-10-01 2020-04-09 パナソニックＩｐマネジメント株式会社 Halide solid electrolyte material and battery using this
WO2020070955A1 (en) 2018-10-01 2020-04-09 パナソニックＩｐマネジメント株式会社 Halide solid electrolyte material and battery using same

Family Cites Families (8)

* Cited by examiner, † Cited by third party
Publication number Priority date Publication date Assignee Title
US8021778B2 (en) * 2002-08-09 2011-09-20 Infinite Power Solutions, Inc. Electrochemical apparatus with barrier layer protected substrate
DE602005017512D1 (en) * 2004-12-08 2009-12-17 Symmorphix Inc DEPOSIT OF LICOO2
US20100104942A1 (en) * 2007-03-26 2010-04-29 Nv Bekaert Sa Substrate for lithium thin film battery
JP2011141982A (en) * 2010-01-06 2011-07-21 Sumitomo Electric Ind Ltd Nonaqueous electrolyte battery
JP5770553B2 (en) 2011-07-26 2015-08-26 日産自動車株式会社 Bipolar lithium-ion secondary battery current collector
JP6078977B2 (en) * 2012-04-18 2017-02-15 富士通株式会社 All solid state secondary battery and its sealing material
EP2897203A4 (en) 2012-09-14 2016-06-01 Nissan Chemical Ind Ltd Composite current collector for energy storage device electrode, and electrode
EP2907190B1 (en) 2012-10-15 2017-12-06 Cymbet Corporation Thin film batteries comprising a glass or ceramic substrate

Also Published As

Publication number Publication date
WO2018095845A1 (en) 2018-05-31
EP3327837A1 (en) 2018-05-30

Similar Documents

Publication Publication Date Title
US20200335756A1 (en) Solid-state battery separators and methods of fabrication
US6805999B2 (en) Buried anode lithium thin film battery and process for forming the same
EP3545577A1 (en) Li-ion based electrochemical energy storage cell
TWI796295B (en) Energy storage device having an interlayer between electrode and electrolyte layer
US9673478B2 (en) Multi-layer coatings for bipolar rechargeable batteries with enhanced terminal voltage
EP2426753B1 (en) Electrochemical apparatus with barrier layer protected substrate
CN102668190A (en) Solid electrolyte cell and cathode active material
JP2009245913A (en) Lithium battery
JP2008112635A (en) All solid lithium ion battery and its manufacturing method
CN117080368A (en) Low melting temperature metal purification and deposition
JP2004127743A (en) Thin film battery
KR100790844B1 (en) Thin film battery and fabrication method thereof
KR20070120734A (en) Anode for rechargeable lithium thin film battery, method of preparing thereof, and rechargeable lithium thin film battery comprising the same
US7524585B2 (en) Anode and battery using it
US20190221890A1 (en) Low-Voltage Microbattery
WO2023197236A1 (en) Battery assembly and manufacturing method therefor
EP4297140A1 (en) Multi-cell monolithic thin-film battery and fabrication method thereof
WO2003043108A1 (en) Buried anode lithium thin film battery and process for forming the same
KR100808933B1 (en) Cathode for rechargeable lithium thin film battery, method of preparing thereof, and rechargeable lithium thin film battery comprising the same
Lee et al. Buried anode lithium thin film battery and process for forming the same
EP3878031A1 (en) A solid-state battery

Legal Events

Date Code Title Description
PUAI Public reference made under article 153(3) epc to a published international application that has entered the european phase

Free format text: ORIGINAL CODE: 0009012

17P Request for examination filed

Effective date: 20190607

AK Designated contracting states

Kind code of ref document: A1

Designated state(s): AL AT BE BG CH CY CZ DE DK EE ES FI FR GB GR HR HU IE IS IT LI LT LU LV MC MK MT NL NO PL PT RO RS SE SI SK SM TR

AX Request for extension of the european patent

Extension state: BA ME

DAV Request for validation of the european patent (deleted)
DAX Request for extension of the european patent (deleted)
STAA Information on the status of an ep patent application or granted ep patent

Free format text: STATUS: THE APPLICATION IS DEEMED TO BE WITHDRAWN

18D Application deemed to be withdrawn

Effective date: 20200116