Bipolar Solid-State Battery Cell

Abstract

The present invention relates to a bipolar solid-state battery cell comprising a plurality of electrochemical units arranged in a stack such that adjacent electrochemical units share an electronic conductor, wherein the plurality of stacked electrochemical units are arranged in series, the bipolar solid-state battery cell comprising: a cathode current collector; a first electrochemical unit comprising a first catholyte layer, a first solid electrolyte, and a first electronic conductor; x second electrochemical units, x being 0 to 8, each comprising a second catholyte layer, a second solid electrolyte, and a second electronic conductor; a third electrochemical unit comprising a third catholyte layer and a third solid electrolyte; an anode current collector; and an electrical insulating layer. The present invention further relates to a bipolar solid-state battery comprising a stack of at least two bipolar solid-state battery cells.

Description

[Technical Field]

[0001] The present invention relates to a bipolar solid-state battery cell, in particular a bipolar solid-state battery cell comprising a plurality of stacked electrochemical units. The present invention further relates to a bipolar solid-state battery comprising a plurality of stacked bipolar solid-state battery cells. [Background technology]

[0002] Secondary batteries have been known for some time. In the search for secondary batteries with high energy density and high power output, bipolar batteries have been developed. In particular, bipolar lithium-ion secondary batteries, or bipolar lithium-ion batteries for short, have attracted much interest.

[0003] A bipolar battery cell comprises a stack of electrochemical units arranged in series, using bipolar electrodes between external cathodes and external anodes, with an electrolyte present between the cathode and adjacent bipolar electrodes, between each adjacent bipolar electrode, and between the anode and adjacent bipolar electrodes.

[0004] EP1487034 discloses a bipolar battery having bipolar electrodes and an electrolyte layer. The bipolar electrodes include a current collector, a positive electrode layer formed on one surface of the current collector, and a negative electrode layer formed on the other surface of the current collector. The bipolar electrodes are laminated together to form a stack structure, providing a series connection through the electrolyte layer. The positive electrode layer, negative electrode layer, and electrolyte layer are potted together in a resin part. The resin part of the battery provides protection against vibration and impact during operation of the vehicle battery and makes the battery water-resistant, heat-resistant, airtight, and electrolyte-resistant.

[0005] Disadvantages of such bipolar battery elements include limited power and energy density, requiring large stacks to achieve sufficient power density. As a result, a lot of heat is generated during use, particularly in the electrochemical cells at the center of the stack. This heat tends to accumulate within the battery elements, causing electrolyte degradation, e.g., oxygen release, which poses safety risks and limits the lifespan of the bipolar battery elements. A further disadvantage is that the resins used as encapsulation materials are known to provide insufficient protection in the event of overvoltage in the battery. Furthermore, when a liquid electrolyte is used, there is a risk of electrolyte leakage, which also poses safety risks.

[0006] US2009017371 discloses a power storage device including multiple electrolyte layers stacked with electrode elements interposed therebetween. To address heat dissipation difficulties, the multiple electrolyte layers include an electrolyte layer provided at a first position and an electrolyte layer provided at a second position different from the first position in the stacking direction, so that head radiation is lower at the second position than at the first position. The electrolyte layer at the second position has a higher resistance value than the resistance value of the electrolyte layer at the first position. The electrolyte may be a solid electrolyte containing particles, where the particle density at the second position is lower than the particle density at the first position.

[0007] The disadvantages of such bipolar batteries are that they are complex to set up and require different compositions of electrolyte layers. Furthermore, bipolar batteries remain limited in power and energy density, and especially in safety during battery use.

[0008] US2008118826 discloses a lithium-ion battery with cell elements including a cathode, an anode, and an electrolyte layer between the cathode and anode, the electrolyte layer comprising an arrangement of insulating particles with a plurality of interstitial spaces therebetween, the electrolyte occupying at least some of the interstitial spaces.

[0009] US2009269665 discloses a bipolar battery with an inorganic solid electrolyte for providing a power storage device that can prevent a decrease in energy efficiency of the power storage device and can avoid fluctuations in temperature distribution.

[0010] JP2019140024 discloses a method for laminating solid electrolyte layers based on sulfides and oxides in a bipolar all-solid-state battery stack.

[0011] A disadvantage of the aforementioned bipolar batteries is that they are prone to overcharging and / or overvoltage, thereby limiting their safety. Summary of the Invention

[0012] It is an object of the present invention to overcome one or more of the aforementioned drawbacks. It is an object of the present invention to provide a bipolar solid-state battery element and a bipolar solid-state battery having a high power density. It is a further object of the present invention to provide a bipolar solid-state battery element and a bipolar solid-state battery having improved safety compared to bipolar solid-state battery elements and bipolar solid-state batteries in the art.

[0013] According to a first aspect of the present invention, there is provided a bipolar solid-state battery cell as set out in the accompanying claims.

[0014] A bipolar solid-state battery cell includes a plurality of electrochemical units arranged in a stack such that adjacent electrochemical units share an electronic conductor, and preferably, the stacked electrochemical units are arranged in series.

[0015] The bipolar solid-state battery cell includes a cathode current collector. The cathode current collector may be any cathode current collector known in the art. Preferably, the cathode current collector comprises or consists essentially of aluminum.

[0016] The bipolar solid-state battery cell further includes a first electrochemical unit, which includes a first catholyte layer, a first solid electrolyte, and a first electronic conductor.

[0017] The first catholyte layer comprises a first active material, which may be any active material known in the art.

[0018] Preferably, the first catholyte layer further comprises an electronically conductive compound and / or an ionically conductive compound. The first catholyte layer may further comprise a binder. The electronically conductive compound, the ionically conductive compound, and the optional binder may be as known in the art.

[0019] Preferably, the first solid electrolyte comprises or consists essentially of an alkali metal, an alkaline earth metal, a transition metal, or a combination thereof. Preferred examples of alkali metals include, but are not limited to, lithium and sodium. For example, the first solid electrolyte may be Li7La3Zr2O 12 (LLZO). Preferred examples of alkaline earth metals include, but are not limited to, magnesium. Preferred examples of transition metals include, but are not limited to, aluminum.

[0020] Preferably, the first electronic conductor comprises or consists essentially of steel, a steel alloy, titanium, a titanium alloy, sintered carbon glass-like carbon (also known under the registered trademark vitreous carbon or glassy carbon), or a combination of two or more thereof. Non-limiting examples of steel include stainless steel, carbon steel, and A36.

[0021] Optionally, the first electrochemical unit further comprises a first anode layer. The first anode layer may be any anode layer known in the art. Preferably, when present, the first anode layer comprises or consists essentially of an alkali metal, an alkaline earth metal, a transition metal, graphite, silicon, carbide, or a combination of two or more thereof.

[0022] The bipolar solid-state battery cell further comprises x number of second electrochemical units, where x is suitably between 0 and 20, such as between 0 and 15, preferably between 0 and 10, more preferably between 0 and 8, such as between 0 and 5, or between 0 and 1. As will be understood, when x is 0, the bipolar solid-state battery cell comprises two electrochemical units, i.e., a first and a third electrochemical unit, whereas the bipolar solid-state battery cell does not comprise any second electrochemical units.

[0023] Each second electrochemical unit, when present (ie, when x is 1 to 8), individually comprises a second catholyte layer, a second solid electrolyte, and a second electronic conductor.

[0024] The second catholyte layer comprises a second active material. The second active material is preferably as described herein above with respect to the first active material. Preferably, the second catholyte layer further comprises an electronically conductive compound and / or an ionically conductive compound. The second catholyte layer may further comprise a binder. The electronically conductive compound, the ionically conductive compound, and the optional binder may be as known in the art.

[0025] When the bipolar solid-state battery cell includes at least two second electrochemical units (i.e., x is 2 to 8), the second electrochemical units may have the same or different (second) catholyte layers. It will be understood that the catholyte layer of each one of the second electrochemical units may be the same as or different from the first catholyte layer of the first electrochemical unit.

[0026] Suitably, the second solid electrolyte is as described herein above with respect to the first solid electrolyte. When the bipolar solid-state battery cell includes two or more second electrochemical units (i.e., x is 2 to 8), the second electrochemical units may have the same or different (second) solid electrolytes. It will be understood that the solid electrolyte of each one of the second electrochemical units may be the same or different from the first solid electrolyte of the first electrochemical unit.

[0027] Suitably, the second electronic conductor is as described herein above with respect to the first electronic conductor. When the bipolar solid-state battery cell includes two or more second electrochemical units (i.e., x is 2 to 8), the second electrochemical units may have the same or different (second) electronic conductors. It will be understood that the electronic conductor of each one of the second electrochemical units may be the same or different from the first electronic conductor of the first electrochemical unit.

[0028] Optionally, if present (i.e., when x is 1 to 8), the second electrochemical unit may further comprise a second anode layer. If the solid-state battery cell comprises two or more second electrochemical units (i.e., when x is 2 to 8), some or all of the second electrochemical units may comprise a second anode layer. Suitably, if present, each second anode layer individually is as described herein above with respect to the optional first anode layer.

[0029] When a bipolar solid-state battery cell includes two or more second electrochemical units (i.e., x is 2 to 8), the second electrochemical units may have the same or different second anode layers. It will be understood that when x is 1 to 8, whether one or more second electrochemical units include a second anode layer is independent of whether the first electrochemical unit includes a (first) anode layer. It will also be understood that each one anode layer of the second electrochemical units, if present, may be the same as or different from the first anode layer of the first electrochemical unit.

[0030] The bipolar solid-state battery cell further includes a third electrochemical unit, which includes a third catholyte layer and a third solid electrolyte.

[0031] The third catholyte layer comprises a third active material. The third active material is preferably as described herein above with respect to the first active material. Preferably, the third catholyte layer further comprises an electronically conductive compound and / or an ionically conductive compound. The third catholyte layer may further comprise a binder. The electronically conductive compound, the ionically conductive compound, and the optional binder may be as known in the art.

[0032] Suitably, the third solid electrolyte is as described herein above with respect to the first solid electrolyte. It will be appreciated that the solid electrolyte of the third electrochemical unit may be the same as or different from the solid electrolyte of the first electrochemical unit and / or the second electrochemical unit where x is 1 to 8.

[0033] Optionally, the third electrochemical unit further comprises a third anode layer. Suitably, if present, the third anode layer is as described herein above with respect to the optional first and / or optional second anode layers. It will be understood that the anode layer of the third electrochemical unit, if present, may be the same as or different from the anode layer of the first electrochemical unit, if present, and / or the second electrochemical unit, if present, where x is 1 to 8.

[0034] The bipolar solid-state battery cell further comprises an anode current collector. The anode current collector may be any anode current collector known in the art. Preferably, the anode current collector comprises or consists essentially of copper.

[0035] The bipolar solid-state battery cell further comprises an electrically insulating layer, suitably arranged to electrically withstand the voltage of the bipolar solid-state battery cell in use.

[0036] Preferably, an electrical insulating layer is provided on the outer surface of the cathode current collector and / or the outer surface of the anode current collector. Preferably, an electrical insulating layer is provided on the outer surface of the cathode current collector. Preferably, and alternatively, an electrical insulating layer is provided on the outer surface of the anode current collector.

[0037] The "outer surface" of a layer of a bipolar solid-state battery cell in this disclosure means the surface facing the outside of the battery cell, i.e., the surface opposite the surface facing the solid electrolyte.

[0038] Preferably, the electrically insulating layer comprises or consists essentially of a polymer, a ceramic material, or a combination of two or more thereof.

[0039] Preferably, but not limited to, the polymer is selected from the group consisting of polyethylene, polypropylene, polystyrene, polytetrafluoroethylene, cellulose, viscose, natural rubber, and synthetic rubber.

[0040] Preferably, but not exclusively, the ceramic material is selected from the group consisting of glass, metal oxide, metal nitride, porcelain, and mica. A preferred example of a metal oxide is alumina. A preferred example of a metal nitride is boron nitride.

[0041] According to a second aspect of the present invention there is provided a bipolar solid state battery as set out in the accompanying claims.

[0042] The bipolar solid-state battery comprises or consists essentially of at least two bipolar solid-state battery cells, the bipolar solid-state battery cells being stacked, and suitably at least one, and preferably all, of the at least two bipolar solid-state battery cells being according to the first aspect of the present disclosure.

[0043] Preferably, the cathode current collectors of at least two, preferably each one, of the at least two bipolar solid-state battery cells are electronically linked together, in particular by connection to a cathode tab, which preferably allows easy coupling of the cathode current collectors to electronic circuits, in particular external electronic circuits (i.e. outside or external to the battery cell).

[0044] Similarly, and preferably, the anode current collectors of at least two, and preferably each one, of the at least two bipolar solid-state battery cells are electronically linked together, in particular by connection to an anode tab, which preferably allows easy coupling of the anode current collector to electronic circuitry, in particular to external electronic circuitry (i.e., outside or external to the battery cell).

[0045] Advantages of the bipolar solid-state battery cell of the present disclosure include, but are not limited to, improved functionality due to the stackability of multiple electrochemical cells, as well as improved safety and reduced or minimized risk of thermal runaway, thereby protecting the battery cell components, particularly the catholyte, anode (if present), and / or electrolyte. Safety is further improved by reducing the risk of leakage of harmful gases released from chemical reactions in the battery components.

[0046] A further advantage of the bipolar solid-state battery cells of the present disclosure is that multiple bipolar SSB cells can be stacked, thereby resulting in a bipolar solid-state battery with increased safety compared to existing SSBs, including but not limited to, by ensuring protection against thermal runaway, particularly during overvoltage or overcharge conditions. [Brief explanation of the drawings]

[0047] Aspects of the present invention will be described in more detail with reference to the accompanying drawings, in which like reference numerals illustrate like features. [Figure 1] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 2] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 3] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 4] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 5] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 6] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 7]1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 8] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 9] 1-9 each show a schematic representation of a bipolar solid-state battery cell according to the present disclosure. [Figure 10] FIG. 10 shows a schematic diagram of a bipolar solid-state battery according to the present disclosure. DETAILED DESCRIPTION OF THE INVENTION

[0048] 1 schematically illustrates a bipolar solid-state battery cell 1 according to the present disclosure. The bipolar solid-state battery cell 1 includes a cathode current collector 2, a first electrochemical unit 3a, a third electrochemical unit 3b, and an anode current collector 8. The bipolar solid-state battery cell 1 does not include any second electrochemical unit, i.e., x is 0.

[0049] Preferably, the anode current collector 8 is as described hereinabove. Preferably, the cathode current collector 2 is as described hereinabove.

[0050] Preferably, and as known in the art, the cathode current collector 2 extends from the bipolar solid-state battery cell 1. In other words, the cathode current collector 2 preferably has a portion that extends or protrudes from the stack comprising the first electrochemical unit 3 a and the third electrochemical unit 3 b. This can be achieved by methods known in the art, for example by providing the cathode current collector 2 with a surface area that is greater than the surface area of ​​the components of the first electrochemical unit 3 a. As is known, such extension or protrusion allows for easy connection or coupling of the cathode current collector 2 to any electronic circuitry (not shown) to which the anode current collector 8 is also preferably connected or coupled. Such electronic circuitry includes, in particular, any external electronic circuitry, i.e., electronic circuitry outside or external to the battery cell.

[0051] Preferably, and as known in the art, the anode current collector 8 extends from the bipolar solid-state battery cell 1. In other words, the anode current collector 8 preferably has a portion that extends or protrudes from the stack comprising the first electrochemical unit 3 a and the third electrochemical unit 3 b. This can be achieved by methods known in the art, for example by providing the anode current collector 8 with a surface area that is greater than the surface area of ​​the components of the third electrochemical unit 3 b. As is known, such extension or protrusion allows for easy connection or coupling of the anode current collector 8 to any electronic circuitry (not shown) to which the cathode current collector 2 is also preferably connected or coupled. Such electronic circuitry includes, in particular, any external electronic circuitry, i.e., electronic circuitry outside or external to the battery cell.

[0052] An electrical insulating layer 9 is provided on the surface of the cathode current collector 2 opposite to the surface facing the first electrochemical unit 3a.

[0053] Preferably, when two or more bipolar solid-state battery cells 1 are stacked to obtain a bipolar solid-state battery, the electrical insulating layer 9 can electrically insulate adjacent bipolar solid-state battery cells 1. In other words, the electrical insulating layer 9 is provided so that the passage of current from one bipolar solid-state battery cell 1 to an adjacent bipolar solid-state battery cell 1 is below a predetermined threshold.

[0054] Preferably, the threshold value is defined by the thickness and the relative dielectric constant of the electrically insulating layer 9. As is known, the relative dielectric constant is defined by the material(s) of which the electrically insulating layer 9 is made.

[0055] Preferably, the thickness of the electrical insulating layer 9 is selected according to characteristic values ​​of voltages defined by the electrochemical units (3a, 3b, and 4 (not present in FIG. 1)) of the bipolar solid-state battery cell 1 and according to set values ​​of voltages that define the safe operating conditions of the bipolar solid-state battery cell 1.

[0056] Preferably, the material, dielectric constant and / or thickness of the electrical insulating layer 9 are selected to ensure the level of electrical insulation necessary to avoid damage to the electrochemical units of the bipolar solid-state battery cell 1. Thus, the electrical insulating layer 9 shall be considered as an adjustable dielectric breakthrough circuit element. Preferably, the dielectric constant, material and / or thickness are selected to match the electrical insulating layer 9 to a desired dielectric breakthrough voltage.

[0057] Preferably, when the total charge voltage of the bipolar solid-state battery cell 1 exceeds a certain value, the electrical insulating layer 9 enters a dielectric breakthrough state. Preferably, in this dielectric breakthrough state, the electrical insulating layer 9 becomes electrically conductive. As a result, the electrical insulating layer 9 in the dielectric breakthrough state allows current to bypass the electrochemical units 3a and 3b (and 4 (not present in FIG. 1)), thereby avoiding damage to the electrochemical units 3a, 3b, and 4 (not present in FIG. 1).

[0058] In other words, the electrically insulating layer 9 can be considered to preferably function as a Zehner diode. Under normal operating conditions, the electrically insulating layer 9 acts as an insulator. Under extreme conditions, particularly when overvoltage and / or overcurrent occurs, the electrically insulating layer 9 becomes electrically conductive, thereby preventing thermal runaway. Thermal runaway is preferably prevented by bypassing energy through an engineered short that includes the electrically insulating layer 9. As a result, electrical energy is preferably not absorbed by the catholyte, anode (if present, not shown in FIG. 1 ), and / or electrolyte, thereby avoiding damage thereto.

[0059] Preferably, the electrical insulating layer 9 protects adjacent bipolar solid-state battery cells stacked in the bipolar solid-state battery from overvoltages of more than 1 time the normal charging voltage of the bipolar solid-state battery cell, for example at least 1.1 times, at least 1.2 times, at least 1.25 times, at least 1.5 times, at least 1.75 times, or at least 2 times. In particular, the electrical insulating layer 9 is provided so that a bipolar solid-state battery comprising a stack of at least two bipolar solid-state battery cells is deemed safe by UN38 testing.

[0060] The first electrochemical unit 3 a includes a first catholyte layer 5 a , a first solid electrolyte 6 a , and a first electron conductor 7 .

[0061] Preferably, the first catholyte layer 5a is as described hereinabove. Preferably, the first catholyte layer 5a contains 50 wt % to 100 wt % of the first active material, based on the total weight of the first catholyte layer 5a.

[0062] Preferably, the first solid electrolyte 6a is as described herein above.

[0063] Preferably, the first electronic conductor 7 is as described herein above. Preferably, the first electronic conductor 7 is provided to restrict and even substantially block the movement of ions between the first 3 a and third 3 b electrochemical units. In other words, the electronic conductor preferably provides ionic resistance while ensuring electronic conductivity between adjacent electrochemical units 3 a, 3 b. As a result, because of the electronic conductivity between adjacent electrochemical units 3 a, 3 b, the first 3 a and third 3 b electrochemical units of the bipolar solid-state battery cell 1 are considered to be connected in series.

[0064] The third electrochemical unit 3b comprises a third catholyte layer 5c and a third solid electrolyte 6c. Preferably, the third catholyte layer 5c is as described herein above. Preferably, the third solid electrolyte 6c is as described herein above.

[0065] Preferably, the third catholyte layer 5c contains 50 wt % to 100 wt % of the third active material based on the total weight of the third catholyte layer 5c.

[0066] 2 shows another bipolar solid-state battery cell 100 according to the present disclosure. The bipolar solid-state battery cell 100 includes a cathode current collector 2, a first electrochemical unit 3a, a third electrochemical unit 3b, and an anode current collector 8, all preferably as described herein above.

[0067] The bipolar solid-state battery cell 100 further comprises an electrical insulating layer 9. The electrical insulating layer 9 is provided on the side or surface of the anode current collector 8 opposite to the side or surface adjacent to the third electrochemical unit 3b. The electrical insulating layer 9 is preferably as described herein above.

[0068] 3 shows yet another bipolar solid-state battery cell 101 according to the present disclosure. The bipolar solid-state battery cell 101 includes a cathode current collector 2, a first electrochemical unit 3a, a third electrochemical unit 3b, and an anode current collector 8, all preferably as described herein above.

[0069] The bipolar solid-state battery cell 101 further comprises a first electrical insulating layer 9 provided on the side of the cathode current collector 2 opposite to the side adjacent to the first electrochemical unit 3 a. The bipolar solid-state battery cell 101 further comprises a second electrical insulating layer 9 provided on the side of the anode current collector 8 opposite to the side adjacent to the third electrochemical unit 3 b. The electrical insulating layer 9 is preferably as described herein above.

[0070] By providing electrical insulating layers 9 on both (opposite) sides of the bipolar solid-state battery cell 101 (thus providing two electrical insulating layers 9), each electrical insulating layer 9 can preferably be thinner when the bipolar solid-state battery cells 101 are stacked to obtain a bipolar solid-state battery than if a single electrical insulating layer 9 were provided, because each electrical insulating layer 9 contributes to the electrical insulation of the (adjacent) bipolar solid-state battery cells 101 of the bipolar solid-state battery.

[0071] 4 shows a bipolar solid-state battery cell 102 according to yet another embodiment of the present invention. The bipolar battery cell 102 includes an electrical insulating layer 9 provided on a surface of the cathode current collector 2 opposite to the surface of the cathode current collector 2 adjacent to the first electrochemical unit 3a. The bipolar solid-state battery cell 102 further includes a third electrochemical unit 3b and an anode current collector 8. Preferably, each of the electrical insulating layer 9, the anode current collector 8 and the cathode current collector 2 is as described herein above.

[0072] The first electrochemical unit 3a comprises a first catholyte 5a, a first solid electrolyte 6a, a first anode layer 10a, and a first electronic conductor 7. The first anode layer 10a is preferably provided between the first solid electrolyte 6a and the first electronic conductor 7. Preferably, the first catholyte 5a, the first solid electrolyte 6a, the first anode layer 10a, and the first electronic conductor 7 are as described herein above.

[0073] The third electrochemical unit 3b includes a third catholyte 5c, a third solid electrolyte 6c, and a third anode layer 10c. The third anode layer 10c is preferably provided between the third solid electrolyte 6c and the anode current collector 8. Preferably, each of the third catholyte 5c, the third solid electrolyte 6c, and the third anode layer 10c is as described herein above.

[0074] Preferably, the first 10a and / or third 10c anode layer comprises or essentially consists of a metal layer. The metal of the metal layer may be the same as or different from one of the metals contained in the cathode, e.g., the cathode active material. For example, if the cathode comprises lithium, the anode layer is preferably a metal layer comprising or essentially consisting of lithium. For example, the anode layer may be lithium foil, optionally doped or substituted with aluminum.

[0075] Alternatively, and also preferably, the anode comprises or consists essentially of an intercalation anode. Non-limiting examples of suitable intercalation electrodes include graphite, Li4Ti5O 12 or a combination thereof.

[0076] Alternatively and also preferably, the first 10a and / or third 10c anode layer comprises or consists essentially of a conversion electrode. Preferably, the conversion electrode comprises or consists essentially of an oxide, a nitride, a sulfide, or a combination of two or more thereof. Non-limiting examples of oxides include LiVO2 and SnO2. Non-limiting examples of nitrides include vanadium nitride (VN) and molybdenum nitride (δ-MoN). Non-limiting examples of sulfides include tin sulfide (SnS x ) and vanadium sulfides (VS2 and VS4).

[0077] Suitably, the first 10a and / or third 10c anode layer may be provided by means known in the art, such as by providing a film, sheet or foil, or by depositing a layer by known methods, such as sputtering and plasma deposition.

[0078] 5 shows a bipolar solid-state battery cell 103 according to yet another embodiment of the present invention. The bipolar battery cell 103 includes an electrical insulating layer 9 provided on a surface of the anode current collector 8 opposite the surface of the anode current collector 8 adjacent to the third electrochemical unit 3b. The bipolar solid-state battery cell 103 further includes a first electrochemical unit 3a and a cathode current collector 2. Preferably, each of the electrical insulating layer 9, the anode current collector 8 and the cathode current collector 2 is as described herein above.

[0079] The first 3a and third 3b electrochemical units are preferably as described herein above with respect to the bipolar solid-state battery cell 102 of FIG. 4, and include first 10a and third 10c anode layers, respectively.

[0080] 6 shows a bipolar solid-state battery cell 104 according to yet another embodiment of the present invention. The bipolar battery cell 104 includes an electrical insulating layer 9 provided on a surface of the cathode current collector 2 opposite the surface of the cathode current collector 2 adjacent to the first electrochemical unit 3a. The bipolar battery cell 104 further includes a second electrical insulating layer 9 provided on a surface of the anode current collector 8 opposite the surface of the anode current collector 8 adjacent to the third electrochemical unit 3b.

[0081] Preferably, each of the electrical insulating layer 9, anode current collector 8 and cathode current collector 2 are as described herein above. Preferably, the first 3a and third 3b electrochemical units are as described herein above with respect to the bipolar solid-state battery cell 102 of Figure 4, and thus include the first 10a and third 10c anode layers, respectively.

[0082] 7 shows a bipolar solid-state battery cell 105 according to a further embodiment of the present invention. The bipolar battery cell 105 includes an electrically insulating layer 9 provided on a surface of the cathode current collector 2 opposite to the surface of the cathode current collector 2 adjacent to the first electrochemical unit 3a. The bipolar solid-state battery cell 105 further includes a third electrochemical unit 3b and an anode current collector 8.

[0083] The first electrochemical unit 3a preferably comprises a first catholyte 5a, a first electrolyte 6a and a first electronic conductor 7, which are preferably as described herein above.

[0084] The third electrochemical unit 3b preferably comprises a third catholyte 5c and a third electrolyte 6c, which are preferably as described herein above.

[0085] The bipolar solid-state battery cell 105 further comprises one second electrochemical unit 4, i.e. x is 1. The second electrochemical unit 4 comprises a second catholyte 5b, a second solid electrolyte 6b, and a second electronic conductor 11. Preferably, the second catholyte 5b and the second solid electrolyte 6b are as described herein above. Preferably, the second electronic conductor 11 is as described herein above, and in particular as described herein above with respect to the first electronic conductor 7.

[0086] Preferably, the first electronic conductor 7 of the first electrochemical unit 3a is arranged to restrict and even substantially block the movement of ions between the first 3a and second 4 electrochemical units. In other words, the first electronic conductor 7 preferably provides ionic resistance while ensuring electronic conductivity between adjacent electrochemical units 3a and 4.

[0087] Preferably, the second electronic conductor 11 of the second electrochemical unit 4 is provided to restrict and even substantially block the movement of ions between the second 4 and third 3b electrochemical units. In other words, the second electronic conductor 11 preferably provides ionic resistance while ensuring electronic conductivity between adjacent electrochemical units 4 and 3b.

[0088] 8 shows a bipolar solid-state battery cell 106 according to yet a further embodiment of the present invention. The bipolar battery cell 106 includes an electrically insulating layer 9 provided on a surface of the cathode current collector 2 opposite to the surface adjacent the first electrochemical unit 3a. The bipolar solid-state battery cell 106 further includes a third electrochemical unit 3b and an anode current collector 8. The first 3a and third 3b electrochemical units are preferably as described herein above with respect to the bipolar solid-state battery cell 105 of FIG.

[0089] The bipolar solid-state battery cell 106 further includes two second electrochemical units 4, i.e., x is 2. The second electrochemical units 4 each preferably include a second catholyte 5b, a second solid electrolyte 6b, and a second electronic conductor 11. Preferably, the second catholyte 5b individually, the second solid electrolyte 6b individually, and the second electronic conductor 11 individually are as described herein above.

[0090] Preferably, the second electronic conductor 11 of a first second electrochemical unit 4 is arranged to restrict and even substantially block the movement of ions between adjacent second electrochemical units 4. Preferably, the second electronic conductor 11 of a second second electrochemical unit 4 is arranged to restrict and even substantially block the movement of ions between the second 4 and third 3b electrochemical units.

[0091] 9 shows a bipolar solid-state battery cell 107 according to yet another embodiment of the present invention. The bipolar battery cell 107 includes an electrically insulating layer 9 provided on a surface of the anode current collector 8 opposite the surface of the anode current collector 8 adjacent to the third electrochemical unit 3b. The bipolar solid-state battery cell 106 further includes a first electrochemical unit 3a and a cathode current collector 2.

[0092] The first electrochemical unit 3a preferably comprises a first catholyte 5a, a first electrolyte 6a, a first anode layer 10a and a first electronic conductor 7, preferably as described herein above.

[0093] The third electrochemical unit 3b preferably comprises a third catholyte 5c, a third electrolyte 6c and a third anode layer 10c, which are preferably as described herein above.

[0094] The bipolar solid-state battery cell 107 further includes one second electrochemical unit 4, i.e., x is 1. The second electrochemical unit 4 includes a second catholyte 5b, a second solid electrolyte 6b, a second anode layer 10b, and a second electronic conductor 11. Preferably, the second catholyte 5b, the second solid electrolyte 6b, the second anode layer 10b, and the second electronic conductor 11 are as described herein above.

[0095] 10 shows a bipolar solid-state battery 200 according to the present disclosure. The bipolar solid-state battery 200 includes a stack of two bipolar solid-state battery cells 107. The presence of the electrical insulating layer 9 allows the individual bipolar solid-state battery cells 107 to function safely as described herein above.

[0096] The cathode current collector 2 of the bipolar solid-state battery cell 107 preferably extends or protrudes from the stack including the first 3a, second 4, and third 3b electrochemical units, thereby allowing for easy connection to each other. As shown in Figure 10, the cathode current collector 2 of the bipolar solid-state battery cell 107 is electronically connected by a cathode tab 12.

[0097] The anode current collector 8 of the bipolar solid-state battery cell 107 preferably extends or protrudes from the stack including the first 3a, second 4, and third 3b electrochemical units, thereby allowing for easy connection to each other. As shown in Figure 10, the anode current collector 8 of the bipolar solid-state battery cell 107 is electronically connected by an anode tab 13.

[0098] Preferably, cathode current collector 2 extends or protrudes in a first direction and anode current collector 8 extends or protrudes in a second direction different from the first direction, allowing for easy connection of cathode current collector 2 to cathode tab 12 and anode current collector 8 to anode tab 13. [Example]

[0099] Example 1 A bipolar solid-state battery cell 102 according to the schematic representation of FIG. 4 was fabricated (i.e., x is 0).

[0100] An aluminum sheet was used for the cathode current collector 2. A copper foil was used for the anode current collector 8.

[0101] The first 5a and third 5c catholytes contained NMC as the active material, carbon nanotubes (CNT) as the electronically conductive compound, and LLZO as the ionically conductive compound.

[0102] The first 6a and third 6c solid electrolytes included LLZO. A 25 μm thick lithium foil was The first 10a and third 10c anode layers were provided. The first electron conductor 7 was an 8 μm thick stainless steel foil.

[0103] A polyethylene foil having a thickness of 600 nm to 800 nm was provided as an electrical insulating layer 9 on the side of the aluminum cathode current collector 2 opposite to the side adjacent to the first catholyte 5a.

[0104] All layers were placed on top of each other in an argon atmosphere to avoid contamination, and the bipolar solid-state battery cell was sealed with an air press.

[0105] The voltage was measured and determined to be 8.4 V to 8.8 V or 4.2 V to 4.4 V on the cathode current collector 2 and electron conductor 7 of the first electrochemical unit 3a, and 4.2 V to 4.4 V on the electron conductor 7 and anode current collector 8 through the third electrochemical unit 3b. [Explanation of symbols]

[0106] 1 Bipolar Solid-State Battery Cell 2. Cathode current collector 3a First Electrochemistry Unit 3b Third Electrochemistry Unit 4. Second Electrochemistry Unit 5a First catholyte layer 5b Second catholyte layer 5c Third catholyte layer 6a First solid electrolyte 6b Second solid electrolyte 6c Third solid electrolyte 7. First electron conductor 8 Anode current collector 9 Electrical insulation layer 10a First anode layer 10b Second Anode Layer 10c Third anode layer 11 Secondary electron conductor 12 Cathode tab for external connection 13 Anode tab for external connection 100 Bipolar Solid State Battery Cells 101 Bipolar Solid-State Battery Cell 102 Bipolar Solid-State Battery Cells 103 Bipolar Solid-State Battery Cells 104 Bipolar Solid-State Battery Cells 105 Bipolar Solid-State Battery Cells 106 bipolar solid-state battery cells 107 Bipolar Solid-State Battery Cells 200 Bipolar Solid State Battery

Claims

1. 1. A bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) comprising a plurality of electrochemical units (3a, 3b, 4) arranged in a stack such that adjacent electrochemical units share an electronic conductor (7, 11), wherein the bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) comprises: - a cathode current collector (2), a first electrochemical unit (3a) comprising a first catholyte layer (5a) containing a first active material, a first solid electrolyte (6a) and a first electronic conductor (7); - x second electrochemical units (4), each second electrochemical unit (4) comprising a second catholyte layer (5b) that comprises a second active material, a second solid electrolyte (6b), and a second electronic conductor (11); a third electrochemical unit (3b) comprising a third catholyte layer (5c) containing a third active material and a third solid electrolyte (6c); - anode current collector (8) and Including, the plurality of stacked electrochemical units (3a, 3b, 4) are arranged in series, and the number x of second electrochemical units (4) is between 0 and 8; The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) further comprises an electrical insulating layer (9) provided on the outer surface of the cathode current collector (2) and / or the outer surface of the anode current collector (8), the electrical insulating layer (9) comprising a ceramic material. Bipolar solid-state battery cells (1, 100, 101, 102, 103, 104, 105, 106, 107).

2. 2. The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) according to claim 1, wherein the electrically insulating layer (9) is arranged to electrically withstand the voltage of the bipolar solid-state battery cell in use.

3. 10. The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, wherein the electrical insulating layer (9) further comprises a polymer.

4. 4. The bipolar solid-state battery cell of claim 3, wherein the polymer is selected from the group consisting of polyethylene, polypropylene, polystyrene, polytetrafluoroethylene, cellulose, viscose, natural rubber, and synthetic rubber.

5. 10. The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, wherein the ceramic material is selected from the group consisting of glass, metal oxide, metal nitride, porcelain, and mica.

6. 10. The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) of any one of the preceding claims, wherein the first electronic conductor (7) and the second electronic conductor (11) individually comprise steel, a steel alloy, titanium, a titanium alloy, glassy carbon, or a combination of two or more thereof.

7. 10. The bipolar solid-state battery cell (102, 103, 104, 107) according to any one of the preceding claims, wherein the first electrochemical unit (3a) further comprises a first anode layer (10a) and / or the third electrochemical unit (3c) further comprises a third anode layer (10c).

8. 10. The bipolar solid-state battery cell (107) according to any one of the preceding claims, wherein x is 1 to 8 and the second electrochemical units (4) each further comprise a second anode layer (10b).

9. 9. The bipolar solid-state battery cell (102, 103, 104, 107) according to any one of claims 7 to 8, wherein the anode layer (10a, 10b, 10c) comprises an alkali metal, an alkaline earth metal, a transition metal, graphite, silicon, a carbide, or a combination of two or more thereof.

10. The first solid electrolyte (6a), if present, the second solid electrolyte (6b), and the third solid electrolyte (6c) are individually selected from an alkali metal, an alkaline earth metal, a transition metal, or a combination thereof, preferably lithium, sodium, magnesium, or aluminum, more preferably Li 7 La 3 Zr 2 O 12 10. The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, comprising (LLZO).

11. 10. The bipolar solid-state battery cell (1, 100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims, wherein the first catholyte layer (5a), if present, the second catholyte layer (5b), and the third catholyte layer (5c) each further comprise one or more of an electronically conducting compound and an ionically conducting compound.

12. A bipolar solid-state battery (200) comprising a stack of at least two bipolar solid-state battery cells (1, 100, 101, 102, 103, 104, 105, 106, 107) according to any one of the preceding claims.

13. 13. The bipolar solid-state battery (200) of claim 12, wherein the cathode current collector (2) of each one of the at least two bipolar solid-state battery cells (1, 100, 101, 102, 103, 104, 105, 106, 107) is electronically coupled to a cathode tab (12).

14. 14. The bipolar solid-state battery (200) according to any one of claims 12 to 13, wherein the anode current collector (8) of each one of the at least two bipolar solid-state battery cells (1, 100, 101, 102, 103, 104, 105, 106, 107) is electronically coupled to an anode tab (13).

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