Alkaline slurry composition, electrode coating, battery, manufacturing process and application

Abstract

The present invention relates to a slurry composition and a sodium battery electrode coating material comprising at least one electrode active material, at least one binder, at least one alkaline additive and optionally at least one conductive agent, the basic additive is selected from the group consisting of metal hydroxides, metal carbonates, metal bicarbonate, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof. The invention further relates to an electrode and a battery comprising said electrode active material or made from said slurry coating. The invention further relates to a method for manufacturing the slurry composition, the electrode coating material thereof, the electrode and the battery.

Description

Technical Field

[0001] This invention relates to sodium-ion batteries, electrodes therein, electrode coatings therein, their manufacturing processes, and their applications. Background Technology

[0002] The demand for electric vehicles and the potential for energy storage is increasing. Current technology uses lithium-ion batteries, which are made of lithium, which is expensive today and sourced only from a few places in the world, such as China and South America. Lithium is not abundant, and as battery demand increases, lithium stocks will be depleted. Lithium-ion batteries may hold the majority market share of rechargeable batteries, but alternatives such as sodium-ion batteries represent an attractive alternative. Sodium-ion batteries contain sodium, a rich and readily available material. Given the raw materials, sodium-ion batteries have shown increasing interest in diversifying the battery industry and also demonstrate good energy storage capacity.

[0003] Since the world's resources are finite, their utilization is crucial. Material recycling, as well as improving battery performance and lifespan, are key to accelerating electrification and increasing the use of renewable energy, thereby more quickly reducing the industrialized world's dependence on oil and gas.

[0004] To meet the demand for batteries, batteries composed of abundant and readily available materials are required. Therefore, new batteries and their components are needed to overcome the problems of conventional products and to provide new batteries with improved performance. Summary of the Invention

[0005] This invention provides a method for improving the adhesion of electrode coatings to current collectors (such as aluminum foil), thereby providing improved cycle life and better performance of sodium-ion batteries. The scope of this invention is defined by the appended claims.

[0006] In one aspect, the present invention relates to a sodium battery electrode coating material, said sodium battery electrode coating material comprising at least one electrode active material, at least one binder, at least one alkaline additive, and optionally at least one conductive agent. The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof.

[0007] In one aspect, the present invention relates to a slurry composition for a sodium battery electrode, said slurry composition comprising at least one electrode active material, at least one binder, at least one alkaline additive, at least one solvent, and optionally at least one conductive agent, and The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof.

[0008] The sodium battery electrode coating material or the slurry composition for the sodium battery electrode, wherein the electrode active material may be selected from cathode active materials (CAM) or anodic active materials (AAM), preferably anodic active materials (AAM).

[0009] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the anode active material (AAM) may include hard carbon, glassy carbon, carbon black, or graphite, or any combination thereof, preferably including hard carbon.

[0010] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the cathode active material (CAM) may include sodium-containing compounds; preferably sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof; preferably sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof; preferably sodium transition metal cyanides having 6 cyano groups per chemical unit; preferably Prussian blue (PB) or its derivative Prussian blue analogues (PBA); preferably Prussian white (PW).

[0011] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the transition metal of the sodium transition metal oxide or sodium transition metal cyanide may be selected from manganese (Mn), iron (Fe), aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), cobalt (Co), or any combination thereof. Preferably, the transition metal of the sodium transition metal oxide or sodium transition metal cyanide is selected from Fe-Fe, Mn-Fe, Fe-Ni, Ni, or Co, more preferably Fe-Fe.

[0012] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the at least one binder may be selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof; preferably, the at least one binder is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof.

[0013] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the alkaline additive may be selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines or amides or oxides or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium; or any combination thereof; Preferably, the additive is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. More preferably, the additive is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. Most preferably, the additive is selected from alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof. For example, the alkaline additive may be sodium hydroxide or ammonium hydroxide.

[0014] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the alkaline additive is present in an amount of 0.0005% to 0.5% by weight of the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive, preferably 0.001-0.1% by weight of the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive, preferably 0.003-0.1%, 0.002-0.008%, 0.005-0.1%, 0.005-0.09%, 0.008-0.07%, 0.01-0.05%, or 0.015-0.04% by weight of the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive.

[0015] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the alkaline additive may be selected from: • Sodium hydroxide (NaOH), provided in an amount of 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. Sodium carbonate (Na₂CO₃) is provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Sodium bicarbonate (NaHCO3), provided in an amount of 0.02-0.09% by weight, preferably 0.021-0.09% or 0.03-0.08%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Ammonium hydroxide (NH4OH), provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Any combination thereof.

[0016] The sodium battery electrode coating material, or the slurry composition for the sodium battery electrode, wherein the at least one conductive agent may be selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof; preferably, the at least one conductive agent is carbon black.

[0017] In one aspect, the present invention relates to a process for producing a slurry composition for a sodium battery electrode according to any one of claims 2 or 3-10, comprising the following steps: a) Provide the at least one electrode active material. b) Provide the at least one adhesive. c) Optionally, the at least one conductive agent is provided. d) Provide the at least one solvent, e) Mix the electrode active material, the at least one binder, the at least one solvent, and the optional at least one conductive agent to obtain a slurry. f) Incorporate at least one alkaline additive into the slurry to increase the pH and provide the slurry composition.

[0018] In one aspect, the present invention relates to a process for producing a sodium battery electrode coating material, comprising providing the aforementioned slurry composition for a sodium battery electrode, or a slurry composition for a sodium battery electrode obtained by the process of the present invention. And further includes the following steps: g) Coating the slurry composition with an increased pH onto the current collector, and h) Dry the coated current collector to provide the sodium battery electrode coating material.

[0019] In the process for producing sodium battery electrode coating materials, the current collector can be a metal foil, preferably an aluminum foil.

[0020] In one aspect, the present invention relates to a process for manufacturing an electrode for a sodium-ion battery, comprising providing a sodium battery electrode coating material, or a sodium battery electrode coating material obtained by the process of the present invention, and further comprising the following steps: i) Calendered and dried coated current collector, and j) Optionally, the calendered current collector is cut.

[0021] In one aspect, the present invention relates to an electrode for a sodium-ion battery, comprising the sodium battery electrode coating material, or comprising a sodium battery electrode coating material obtained by the process for producing the sodium battery electrode coating material; or obtained by the process for manufacturing an electrode for a sodium-ion battery.

[0022] In one aspect, the present invention relates to a method for manufacturing a sodium-ion battery cell, comprising the following steps: i. Provide at least one first electrode, or obtain it through the process of the present invention. ii. Provide at least one second electrode with opposite electrical polarity, iii. Optionally, the at least one first electrode and the at least one second electrode are split. iv. Provide at least one diaphragm, v. Assembling the at least one first electrode, the at least one second electrode, and at least one diaphragm by stacking and / or winding. vi. Optionally, dry the assembled at least one first electrode, at least one second electrode, and at least one diaphragm. vii. Arrange the optionally dried and assembled at least one first electrode, at least one second electrode, and at least one separator in a battery case. viii. Fill the battery casing with electrolyte. ix. Seal the battery casing to form a battery cell.

[0023] The method for manufacturing a sodium-ion battery cell, wherein the at least one first electrode may be an anode, and the at least one second electrode may be a cathode.

[0024] The method for manufacturing a sodium-ion battery cell, wherein the separator may be selected from chemically stable and electrically insulating materials, preferably selected from polyolefins such as polypropylene or polyethylene; cellulose; glass fiber; or any combination thereof.

[0025] In one aspect, the present invention relates to a sodium-ion battery cell obtained by the method of the present invention.

[0026] In one aspect, the present invention relates to the use of the electrode of the present invention in a sodium-ion battery. Attached Figure Description

[0027] Figure 1 A graph showing the cycling curves of button cell cells with and without (for reference) alkaline additives in the anode electrode coating is presented.

[0028] Figure 2 The graph shows the discharge decay rate as a function of cycle number for the anode electrode coating with and without (for reference) alkaline additives.

[0029] Figure 3 The graph shows the discharge decay rate as a function of cycle number when NaOH (measured at three different concentrations) or NH4OH is used as an alkaline additive in the anode electrode coating. Detailed Implementation

[0030] This invention relates to a sodium battery electrode coating material, which includes at least one electrode active material, at least one binder, at least one alkaline additive, and optionally at least one conductive agent.

[0031] The present invention also relates to a slurry composition for a sodium battery electrode, the slurry composition comprising at least one electrode active material, at least one binder, at least one solvent, at least one alkaline additive, and optionally at least one conductive agent.

[0032] The electrode active material used in the coating material or slurry composition can be selected from cathode active materials (CAM) or anodic active materials (AAM). However, the electrode active material is preferably an anodic active material (AAM). The sodium battery electrode coating material is preferably a sodium anode electrode coating material. The slurry composition for the electrode is preferably a slurry composition for the anode electrode. The electrode active material can be provided as a fine powder.

[0033] The anode active material (AAM) can be hard carbon, glassy carbon, carbon black, or graphite, or any combination thereof, preferably hard carbon.

[0034] The cathode active material (CAM) may include sodium-containing compounds; preferably sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof; preferably sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof; preferably sodium transition metal cyanides having six cyano groups per chemical unit; preferably Prussian blue (PB) or its derivative Prussian blue analogues (PBA); preferably Prussian white (PW).

[0035] The general chemical formula for Prussian blue analogues (PBA) can be represented as A. a M b [M' c (CN)6]d , where A is sodium, and 1 < a ≤ 2, where M and M' are transition metals, preferably selected from iron and / or manganese, where 0 < b < 2, 1 < c < 2, and where 1 < d < 2. The anhydrous phase and the hydrated phase of Prussian white can be preferred.

[0036] The transition metals of the sodium transition metal oxide or sodium transition metal cyanide can be selected from manganese (Mn), iron (Fe), aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), cobalt (Co), or any combination thereof. Preferred transition metals of the sodium transition metal oxide or sodium transition metal cyanide can be selected from Fe-Fe, Mn-Fe, Fe-Ni, Ni, or Co. Preferred are Prussian blue analogs (PBA) selected from Fe-Fe-PBA, Mn-Fe-PBA, Fe-Ni-PBA, Ni-PBA, Co-PBA, or any combination thereof, especially Fe-Fe-PBA.

[0037] At least one binder used in the coating material or slurry composition can be selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA), and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof; preferably, the at least one binder is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof.

[0038] The alkaline additives used in the coating material or slurry composition are selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof. The alkaline additives used can be selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines or amides or oxides or cyanides of metals from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium; or any combination thereof; and preferably, selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyanide groups; or any combination thereof, even more preferably, selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyanide groups; or any combination thereof, most preferably, selected from alkali metal hydroxides such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof.

[0039] The compound used as an alkaline additive may be a metal amine comprising one to four amine groups per chemical unit, a metal oxide comprising one to four oxygen atoms per chemical unit, or a metal cyanide comprising one to four cyano groups per chemical unit. For example, the alkaline additive of the present invention may be sodium hydroxide or ammonium hydroxide.

[0040] The term "ammonia" is the common name for ammonium hydroxide (NH4OH). Ammonia is a gas that dissolves in water to form an aqueous solution of alkali, namely ammonia water or ammonium hydroxide. Therefore, ammonium hydroxide can also be an alkaline additive.

[0041] Alkaline additives are used to clean, etch, and activate current collectors, such as aluminum foil, to improve coatability. Small amounts of alkaline additives raise the pH to some extent, where a positive adhesion effect is observed. While alkaline additives can also be used as pre-sodiumning media to mitigate the low initial efficiency of sodium batteries, in this case, sodium ions are consumed or sacrificed by forming a solid electrolyte interface (SEI). Here, the pre-sodiumning effect is directly related to the molar concentration, or amount, of sodium used. Typically, small amounts of sodium salt, for example, less than or equal to 0.1% by weight based on the total weight of the electrode active material, such as sufficient to coat the slurry composition onto the surface of the current collector according to the invention, such as aluminum foil, will show substantially imperceptible effects in terms of sacrificial pre-sodiumning with sodium salt.

[0042] Alkaline additives can be selected from: • Sodium hydroxide (NaOH), provided in an amount of 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. Sodium carbonate (Na₂CO₃) is provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Sodium bicarbonate (NaHCO3), provided in an amount of 0.02-0.09% by weight, preferably 0.021-0.09% or 0.03-0.08%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Ammonium hydroxide (NH4OH), provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Any combination thereof.

[0043] The alkaline additive may preferably be selected from one of the following: • Sodium hydroxide (NaOH), provided in an amount of 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. Sodium carbonate (Na₂CO₃) is provided in an amount of 0.010-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Sodium bicarbonate (NaHCO3), provided in an amount of 0.02-0.09% by weight, such as 0.021-0.09% or 0.03-0.08%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Ammonium hydroxide (NH4OH), provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Sodium hydroxide (NaOH) and sodium carbonate (Na₂CO₃), wherein the amount of NaOH provided is 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode, and the amount of Na₂CO₃ provided is 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Sodium hydroxide (NaOH) and sodium bicarbonate (NaHCO3), wherein the amount of NaOH provided is 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive of the electrode, and the amount of NaHCO3 provided is 0.02-0.09% by weight, preferably 0.021-0.09% or 0.03-0.08%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive of the electrode, or • Sodium hydroxide (NaOH) and ammonium hydroxide (NH4OH), wherein the amount of NaOH provided is 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent and any alkaline additive of the electrode, and the amount of ammonium hydroxide (NH4OH) provided is 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent and any alkaline additive of the electrode.

[0044] The amounts of sodium hydroxide, sodium carbonate, sodium bicarbonate, and ammonium hydroxide are based on the pKa value of each alkaline additive, as the pKa value determines the effectiveness of the etching effect and the required alkali concentration in the process. Generally, alkalis with higher pKa values ​​are more effective in terms of etching effect and adhesion. While sodium hydroxide has a pKa value of 15.7, sodium carbonate has a value of only 10.33. The advantage of using hydroxides instead of carbonates is that no gas is released during the reaction. According to the invention, sodium hydroxide is the most preferred alkaline additive because it requires a smaller mass of additive to achieve the desired etching effect compared to sodium carbonate.

[0045] Alkaline additives can be provided to obtain a slurry composition with a pH of about 8-13, such as about 9-13, or about 9.5-13.

[0046] The alkaline additive may be present in an amount of 0.0005% to 0.5% by weight of the total weight of the electrode-based active material, binder, any conductive agent, and any alkaline additive, preferably in an amount of 0.001-0.1% by weight of the total weight of the electrode-based active material, binder, any conductive agent, and any alkaline additive, preferably in an amount of 0.003-0.1%, 0.002-0.008%, 0.005-0.1%, 0.005-0.09%, 0.008-0.07%, 0.01-0.05%, or 0.015-0.04% by weight of the total weight of the electrode-based active material, binder, any conductive agent, and any alkaline additive.

[0047] If present, at least one conductive agent may be selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof; preferably, the at least one conductive agent is carbon black. It should be noted that if an anodic active material comprising carbon black and / or graphite is used, then a conductive agent is not required in the slurry composition of the present invention or the coating material provided herein. Therefore, if carbon black and / or graphite are provided as one or more anodic active materials, no further conductive agent is provided to obtain the slurry composition, coating material, or electrode of the present invention presented herein.

[0048] If the slurry composition or sodium-ion battery electrode coating material of the present invention is intended for use in the anode, it may each comprise at least one anode active material, preferably hard carbon; at least one binder, preferably selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof, more preferably, the at least one binder is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof; optionally, at least one conductive agent, preferably selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or other materials. Any combination, more preferably carbon black; and at least one alkaline additive selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof, preferably selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal silicates, ammonia or ammonium hydroxide, amines or amides or oxides or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, or any combination thereof, and more preferably selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia or ammonium hydroxide, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical unit having 1 to 4 cyano groups, or any combination thereof. The slurry composition or sodium-ion battery electrode coating material may include at least one anode active material, which is hard carbon; at least one binder, which is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof; optionally at least one conductive agent, which is carbon black; and at least one alkaline additive selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyano groups, or any combination thereof.

[0049] This invention relates to a process for producing the slurry composition for sodium battery electrodes of the present invention, the process comprising the following steps: a) Provide the at least one electrode active material. b) Provide the at least one adhesive. c) Optionally, the at least one conductive agent is provided. d) Provide the at least one solvent, e) Mix the electrode active material, the at least one binder, the at least one solvent, and the optional at least one conductive agent to obtain a slurry. f) Incorporate at least one alkaline additive into the slurry to increase the pH and provide the slurry composition.

[0050] The electrode active material can be provided as a fine powder. The electrode active material can be ground into a fine powder prior to being provided.

[0051] Alkaline additives can be provided to obtain a pH of about 8-13, such as 9-13 or 9.5-13, for slurry compositions.

[0052] This article provides a process for producing a slurry composition for sodium battery electrodes, the process comprising the following steps: a) Provide at least one anode active material, preferably hard carbon, or Provides at least one cathode active material, preferably selected from sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof; preferably sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof; preferably selected from sodium transition metal cyanides having 6 cyano groups per chemical formula unit; more preferably selected from Prussian blue (PB) or its derivative Prussian blue analogues (PBA); preferably Prussian white (PW); b) Provide at least one adhesive, preferably selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof; more preferably, the at least one adhesive is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof. c) Optionally, at least one conductive agent is provided, preferably selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, more preferably carbon black. d) Provide at least one solvent, preferably selected from water or an organic solvent, e) Mix the electrode active material, the at least one binder, the at least one solvent, and the optional at least one conductive agent to obtain a slurry. f) Incorporating at least one alkaline additive into the slurry to obtain a slurry composition with an increased pH. The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof. Preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines, amides, oxides, or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium; or any combination thereof; and More preferably, the cyanide is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. Even more preferably, the cyanide is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. Most preferably, the cyanide is selected from alkali metal hydroxides; and ammonia; or any combination thereof. For example, the alkali metal hydroxide may be selected from lithium hydroxide, sodium hydroxide, and potassium hydroxide. The alkaline additive may also be ammonium hydroxide.

[0053] Adding at least one basic additive to the slurry as the final step in slurry preparation is important. If the basic additive is not added last, it will interact with one or more of the included components, thus reducing its activity and affecting subsequently added components. If the basic additive is not added last, the resulting slurry will not provide the desired effect to increase the performance or cycle life of the electrode or battery obtained from the slurry. Adding the basic additive after mixing other components is important for ensuring improved adhesion to the current collector (e.g., aluminum foil), to which the slurry is provided during the manufacture of the electrode (preferably the anode).

[0054] This invention relates to a process for producing a sodium battery electrode coating material of the present invention, the process comprising providing a slurry composition for a sodium battery electrode, or a slurry composition for a sodium battery electrode of the present invention obtained thereby by the process of the present invention. And further includes the following steps: g) Coating the slurry composition with an increased pH onto the current collector, and h) Dry the coated current collector to provide the sodium battery electrode coating material.

[0055] The current collector can be a metal foil, preferably an aluminum foil.

[0056] This article provides a process for producing a sodium battery electrode coating material, the process including providing a slurry composition for sodium battery electrodes, comprising the following steps: a) Provide at least one anode active material, preferably hard carbon, or Provides at least one cathode active material, preferably selected from sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof; preferably sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof; preferably selected from sodium transition metal cyanides having 6 cyano groups per chemical formula unit; more preferably selected from Prussian blue (PB) or its derivative Prussian blue analogues (PBA); preferably Prussian white (PW); b) Provide at least one adhesive, preferably selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof; more preferably, the at least one adhesive is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof. c) Optionally, at least one conductive agent is provided, preferably selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, more preferably carbon black. d) Provide at least one solvent, preferably selected from water or an organic solvent, e) Mix the electrode active material, the at least one binder, the at least one solvent, and the optional at least one conductive agent to obtain a slurry. f) Incorporating at least one alkaline additive into the slurry to obtain a slurry composition with an increased pH. g) Coating a slurry composition with an increased pH onto the current collector, preferably aluminum foil, and h) Dry the coated current collector to provide sodium battery electrode coating material. The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof. Preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines, amides, oxides, or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium; or any combination thereof. More preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. More preferably, it is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof; Even more preferably, the hydroxide is selected from alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof; and Most preferably, sodium hydroxide; ammonium hydroxide; or any mixture thereof.

[0057] Drying is performed to fix the coated material onto the current collector and remove any residual solvent. Drying can be carried out in an oven.

[0058] This invention relates to a process for manufacturing electrodes for sodium-ion batteries, the process comprising providing a sodium battery electrode coating material of the present invention, or a sodium battery electrode coating material of the present invention obtained by the process therefrom, and further comprising the following steps: i) Calendered and dried coated current collector, and j) Optionally, the calendered current collector is cut.

[0059] This article provides a process for manufacturing electrodes, which includes the following steps: a) Provide at least one anode active material, preferably hard carbon, or Provides at least one cathode active material, preferably selected from sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof; preferably sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof; preferably selected from sodium transition metal cyanides having 6 cyano groups per chemical formula unit; more preferably selected from Prussian blue (PB) or its derivative Prussian blue analogues (PBA); preferably Prussian white (PW); b) Provide at least one adhesive, preferably selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof; more preferably, the at least one adhesive is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof. c) Optionally, at least one conductive agent is provided, preferably selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, more preferably carbon black. d) Provide at least one solvent, preferably selected from water or an organic solvent, e) Mix the electrode active material, the at least one binder, the at least one solvent, and the optional at least one conductive agent to obtain a slurry. f) Incorporating at least one alkaline additive into the slurry to obtain a slurry composition with an increased pH. g) Coating a slurry composition with an increased pH onto the current collector, preferably aluminum foil, and h) Dry the coated current collector to provide sodium battery electrode coating material. i) Calendered and dried coated current collector, and j) Optionally, the calendered current collector is cut. The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof. Preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines, amides, oxides, or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium; or any combination thereof. More preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. More preferably, it is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof; Even more preferably, it is selected from alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof; or Most preferably, sodium hydroxide; ammonium hydroxide; or any mixture thereof.

[0060] The above-described process is a process for manufacturing electrodes, including the process according to the present invention for obtaining a slurry composition and a sodium battery electrode coating material.

[0061] Drying is performed to fix the coated material onto the foil and remove any residual solvent. Drying can be carried out in an oven.

[0062] The calendering of dried coated metal foil involves compressing and flattening the coating through a series of rollers to ensure uniform thickness and proper adhesion.

[0063] The resulting coated anode and cathode foils are then prepared to be cut to size and combined with other components to build battery cells, such as sodium-ion battery cells.

[0064] This article provides a sodium-ion battery anode electrode, comprising at least one anode active material, preferably hard carbon; at least one binder, preferably selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof, more preferably, the at least one binder is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof; optionally, at least one conductive agent, preferably selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, more preferably carbon black. The anode electrode comprises at least one alkaline additive selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof, preferably selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal silicates, ammonia or ammonium hydroxide, amines or amides or oxides or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, or any combination thereof, more preferably selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia or ammonium hydroxide, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical unit having 1 to 4 cyano groups, or any combination thereof. The anode electrode may further comprise a current collector of aluminum foil. The anode electrode of a sodium-ion battery may include at least one anode active material, which is hard carbon; at least one binder, which is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof; optionally at least one conductive agent, which is carbon black; and at least one alkaline additive selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia or ammonium hydroxide, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups, or any combination thereof.

[0065] This document provides a sodium-ion battery cathode electrode, comprising at least one cathode active material selected from sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof, preferably sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof, preferably sodium transition metal cyanides having six cyano groups per chemical unit, more preferably Prussian blue (PB) or its derivative Prussian blue analogues (PBA); preferably Prussian white (PW); and at least one binder, preferably selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof, more preferably, the at least one binder being sodium carboxymethyl cellulose (Na-CMC) or styrene-butadiene rubber (SBR). The cathode electrode may include: at least one conductive agent, preferably selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, more preferably carbon black; and at least one alkaline additive selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof, preferably selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, alkali metal silicates, ammonia or ammonium hydroxide, amines or amides or oxides or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, or any combination thereof, and more preferably selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia or ammonium hydroxide, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical unit having 1 to 4 cyano groups, or any combination thereof. The cathode electrode may further comprise a current collector of aluminum foil.

[0066] Some advantages of using aluminum as a current collector are that it is one of the most abundant elements in the Earth's crust and is easily recycled. Aluminum can be easily formed in roll-to-roll processing. Therefore, having aluminum in both the anode and cathode electrodes can be beneficial.

[0067] The inventors unexpectedly discovered that a specified amount of alkaline additive improves adhesion to the current collector and provides an electrode with relatively low charge transfer resistance. The interaction between the aluminum current collector and the alkaline additive increases the surface area of ​​the aluminum current collector. The increased surface area leads to an increased contact area / interface between the coating and the aluminum current collector, thereby improving mechanical adhesion and providing relatively low charge transfer resistance. Excessive amounts of alkaline additive can lead to the risk of inducing, for example, extensive pitting corrosion on the aluminum current collector. The formation of perforations on the aluminum cathode foil can indicate extensive pitting corrosion. Such perforations can be observed, for example, using a scanning electron microscope (SEM). Extensive pitting corrosion can be detrimental to the electrode and lead to poor cycle performance or failure of the battery cell. The specified amount advantageously allows for low-level pitting corrosion. Herein, the term "pitting corrosion" refers to a form of localized corrosion that forms pits or holes on a metal surface. Pitting corrosion is known to those skilled in the art.

[0068] This invention relates to an electrode for a sodium-ion battery, comprising the sodium battery electrode coating material of the present invention, or comprising the sodium battery electrode coating material of the present invention obtained by the process of producing the sodium battery electrode coating material of the present invention; or obtained by the process of the present invention for manufacturing an electrode for a sodium-ion battery. If the anode of the sodium-ion battery includes at least one alkaline additive, the cathode may include at least one alkaline additive as an optional feature.

[0069] This invention relates to a method for manufacturing sodium-ion battery cells, comprising the following steps: i. Provide at least one first electrode according to the invention or obtained by the process of the invention. ii. Provide at least one second electrode with opposite electrical polarity, iii. Optionally, the at least one first electrode and the at least one second electrode are split. iv. Provide at least one diaphragm, v. Assembling the at least one first electrode, the at least one second electrode, and at least one diaphragm by stacking and / or winding. vi. Optionally, dry the assembled at least one first electrode, at least one second electrode, and at least one diaphragm. vii. Arrange the optionally dried and assembled at least one first electrode, at least one second electrode, and at least one separator in a battery case. viii. Fill the battery casing with electrolyte. ix. Seal the battery casing to form a battery cell.

[0070] Preferably, the process involves the drying assembly of at least one first electrode, at least one second electrode, and at least one diaphragm.

[0071] At least one first electrode according to the invention is preferably an anode, and at least one second electrode is a cathode. At least one electrode of the sodium-ion battery cell is an electrode according to the invention, i.e., an electrode produced by the process according to the invention, which involves providing the slurry composition and coating material of the invention onto a current collector. The sodium-ion battery cell may be provided with an anode and / or cathode according to the invention, and preferably at least the anode is according to the invention.

[0072] In this document, the term "singulation" refers to cutting, such as cutting a sheet of material into several smaller portions. For example, electrode sing can be understood as cutting one or more smaller electrodes from a larger electrode, such as an aluminum sheet or foil coated with a sodium-ion battery electrode coating material. Singulation steps can be performed to obtain electrodes of a specific size and shape. Singulation can be performed using techniques known in the art, such as laser cutting, mechanical cutting, or punching.

[0073] The diaphragm can be selected from chemically stable and electrically insulating materials, preferably polyolefins such as polypropylene or polyethylene; cellulose; glass fiber; or any combination thereof. The provided diaphragm can be made from a single layer of polymer, such as polypropylene (PP) or polyethylene (PE), or from multiple layers of polymer, such as bilayer (e.g., PP / PE) or trilayer (e.g., PP / PE / PP or PE / PP / PE).

[0074] The electrolyte used in sodium-ion batteries may include sodium compositions, such as sodium salts, for example sodium hexafluorophosphate; organic carbonates, such as propylene carbonate, ethylene carbonate, vinylene carbonate, methyl ethyl carbonate, dimethyl carbonate, or diethyl carbonate; or any combination thereof.

[0075] This article provides a method for manufacturing sodium-ion battery cells, including the following steps: i. Provide at least one electrode as a cathode, ii. Provide at least one electrode as the anode, iii. Optionally split the cathode and anode. iv. Provide at least one diaphragm, v. Preferably, the cathode, anode, and diaphragm are assembled by stacking and / or winding. vi. Optionally dry the assembled cathode, anode, and diaphragm. vii. Arrange the optionally dried and assembled cathode, anode, and separator in the battery case. viii. Fill the battery casing with electrolyte. ix. Seal the battery casing to form a battery cell. Wherein, at least one electrode serving as the cathode includes: - At least one cathode active material, selected from sodium metal, sodium-containing alloys, sodium-containing oxides, sodium-containing cyanides, or any combination thereof; preferably selected from sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof; preferably selected from sodium transition metal cyanides having 6 cyano groups per chemical formula unit; preferably Prussian blue (PB) or a derivative of Prussian blue analogue (PBA); preferably Prussian white (PW). - At least one adhesive selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof. Preferably, the at least one adhesive is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof. -At least one conductive agent, optionally selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, preferably carbon black, and -Optional at least one alkaline additive, selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof; Preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines, amides, oxides, or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium; or any combination thereof. More preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. More preferably, it is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof; Even more preferably, the hydroxide is selected from alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof; and Most preferably, sodium hydroxide; ammonium hydroxide; or any mixture thereof. Wherein, at least one electrode serving as the anode includes: - is at least one anode active material of hard carbon. - At least one adhesive selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof. Preferably, the at least one adhesive is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof. -At least one conductive agent, optionally selected from carbon black, graphite, graphene, carbon nanotubes (CNTs), or any combination thereof, preferably carbon black, and - At least one alkaline additive selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof; Preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines, amides, oxides, or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium; or any combination thereof. More preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. More preferably, it is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof; Even more preferably, the hydroxide is selected from alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof; and Most preferably, sodium hydroxide; ammonium hydroxide; or any mixture thereof. At least one diaphragm includes: - At least one separator comprises polyolefin, cellulose, glass fiber or any combination thereof, preferably polypropylene, polyethylene or any combination thereof, preferably a single layer of polypropylene or polyethylene, or a double layer of polypropylene and polyethylene, or a triple layer of polypropylene / polyethylene / polypropylene or polyethylene / polypropylene / polyethylene.

[0076] This article also provides a sodium-ion battery cell obtained by the method of the present invention.

[0077] The sodium-ion battery of the present invention may include an anode comprising: at least one anode active material, which is hard carbon; at least one binder, which is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof; optionally at least one conductive agent, which is carbon black; and at least one alkaline additive selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia or ammonium hydroxide, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical unit having 1 to 4 cyano groups, or any combination thereof. The anode electrode may further comprise a current collector, which is an aluminum foil. The sodium-ion battery of the present invention may further include a cathode comprising: at least one cathode active material selected from sodium transition metal oxides, sodium transition metal cyanides, or any combination thereof, preferably selected from sodium transition metal cyanides having six cyano groups per chemical unit, more preferably selected from Prussian blue (PB) or its derivatives Prussian blue analogs (PBA), such as Prussian white (PW); at least one binder, such as sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof; optionally at least one conductive agent, such as carbon black; and optionally at least one alkaline additive selected from alkali metal hydroxides, alkali metal carbonates, alkali metal bicarbonates, ammonia or ammonium hydroxide, cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium, or thallium, each chemical unit having 1 to 4 cyano groups, or any combination thereof. The cathode electrode may further comprise a current collector of aluminum foil. The sodium-ion battery of the present invention may further comprise an electrolyte.

[0078] The present invention also relates to the use of electrodes obtained according to the process used to manufacture electrodes in sodium-ion batteries.

[0079] Example Example 1: Preparation of slurry compositions with and without (as a reference) and characterization of coin cell cells produced from the different slurry compositions. For the experiment, the coin cell was assembled. The provided cathode consisted of Prussian white sodium. 2-xFe[Fe(CN)6]·mH2O, having a Na content higher than 1.8 and a negligible water content. The cathode coating on the current collector (aluminum foil) comprises, by weight, 93% cathode active material (Prussian white), 3% conductive additive (carbon black), and 4% binder (1% carboxymethyl cellulose and 3% styrene-butadiene rubber) based on the total weight of the present cathode active material, conductive agent, binder, and any alkaline additives. Furthermore, in this embodiment, as a reference example, no alkaline additives are present in the cathode coating. The provided anode comprises hard carbon as the anode. The anodic coating on the current collector (aluminum foil) comprises, by weight, 96% anodic active material (hard carbon), 4% binder (2% sodium carboxymethyl cellulose and 2% styrene-butadiene rubber), and 0 (for reference) or 0.017% alkaline additive (sodium hydroxide) based on the total weight of the present anodic active material, binder, any conductive agent, and any alkaline additive. Furthermore, in this embodiment, as a reference example, the anodic coating does not contain conductive additives.

[0080] The cathode diameter is 13 mm, and the anode diameter is 16 mm. The mass loading is 22.7 mg / cm². 2 The cathode electrode is manufactured by coating an aluminum current collector with a slurry comprising Prussian white mixed with a solvent (water), conductive additives, and a binder. The mass loading is 13 mg / cm². 2 The anode electrode is manufactured by coating an aluminum current collector with a slurry comprising a mixture of hard carbon and solvent (water), conductive additives, binder, and alkaline additives. To obtain the alkaline slurry composition, a mixture of hard carbon, solvent, and conductive additives is mixed with 0.017% by weight of alkaline additive NaOH relative to the anode solids content. A Celgard® PP / PE / PP triple layer is used as the separator. The electrolyte is provided as 70 μl of NaPF6 injected into a carbonate mixture. The electrolyte comprises 16 wt% NaPF6 in a carbonate mixture comprising: 11 wt% ethylene carbonate (EC), 10 wt% propylene carbonate (PC), 32 wt% ethyl methyl carbonate (EMC), and 31 wt% diethyl carbonate (DEC). The battery cell is then assembled and finalized.

[0081] Figure 1 and Figure 2 The voltage distribution was measured using a Neware BTS82 battery testing system with a standard method of constant current cycling. The standardized test is constant current cycling, in which a constant current (defined herein as C-rate) is applied. For Figure 1 and Figure 2 The constant current cycling of the battery cell is carried out at 1.8-3.8 V.

[0082] Figure 1 The cycling curve of a button cell is shown, which is cycled at a C-rate of C / 2. Figure 2 The 15th charge-discharge cycle was depicted with and without alkaline slurries. From Figure 1 It can be seen that a higher specific capacity was obtained by using alkaline slurry.

[0083] Figure 2 The discharge decay rate with and without alkaline slurry is shown as a function of cycle number during cycling at different C-ratios (C / 10, C / 5, C / 5, C / 2, C / 1). Figure 2 It can be seen that the use of alkaline slurry improves the stability at different C-ratios, especially with the increase of the number of cycles.

[0084] Example 2: Different slurry compositions with different amounts of alkaline additives were prepared, and button cell cells produced from the different slurry compositions were characterized. A master slurry was prepared by mixing water, hard carbon, binder, and conductive carbon using a planetary mixer. The resulting master slurry comprised approximately 93 wt% hard carbon, approximately 4.0 wt% binder, and approximately 3 wt% conductive carbon by weight. The master slurry was divided into four containers, each containing 500 g of master slurry. Four (4) sample slurries were prepared by adding specific amounts of alkaline additives to each container. The weight percentage of each alkaline additive added to sample slurries 1–4 relative to the component ratios, i.e. relative to hard carbon, binder, and conductive carbon, is presented in Table 1.

[0085] Subsequently, each of the sample slurries 1-4 was coated onto the aluminum foil sheet using a reverse comma coating machine to obtain coated aluminum sheets. After coating, the coated sheets were subjected to a calendering process.

[0086] Table 1: Types and amounts of alkaline additives present in samples 1-4. The wt% of alkaline additives was calculated as a percentage of the total amount. For the hard carbon, binder and conductive carbon present in each of the corresponding slurries.

[0087]

[0088] After rolling, each coated aluminum sheet is laser-cut into 13 mm circular electrodes. The electrodes are then dried at 140°C for 16 hours to form an electrode including the electrode coating. The content of the electrode coating corresponds to the content of the slurry (excluding water) used to manufacture the electrode.

[0089] Subsequently, four (4) types of half-cell units, namely button cell units, were assembled, including a 15 mm sodium metal electrode (i.e., sodium metal pressed onto an aluminum sheet), a polypropylene separator, an electrolyte consisting of 1 M NaPF6 in diethylene glycol dimethyl ether, and an electrode generated from one of sample slurry 1, sample slurry 2, sample slurry 3, or sample slurry 4.

[0090] For electrochemical evaluation, each of the four coin cell cell types was subjected to constant current cycling. All coin cell cells were subjected to three charge-discharge cycles at a C / 10 rate, followed by subsequent cycles at gradually increasing current rates of C / 5, C / 3, C / 2, and C / 1. Discharging the coin cell cells involved desodiation of the hard carbon-containing electrodes.

[0091] Figure 3 The discharge decay rate of button cell cells generated from sample slurries 1 through 3 as a function of cycle number is shown. These slurries contain different amounts of sodium hydroxide in the electrodes: 0.005 wt%, 0.05 wt%, and 0.1 wt%, respectively. Furthermore, Figure 3 The discharge decay rate of coin cell units produced from sample slurry 4 containing 0.05 wt% ammonium hydroxide as a function of cycle number is also shown, wherein sample 4 provides an amount of alkaline additive approximately equal to that of sample solution 2. Coin cell units produced from sample slurries 1 through 4 were cycled at different C-rates (C / 10, C / 5, C / 3, C / 2, and C / 1). Figure 3 It can be seen that for different concentrations, the stability at C / 10, C / 5, and C / 3 remains basically the same with different C-rates, while the stability of the coin cell decreases significantly at higher discharge times, i.e., for sample slurry 1 at C / 2. Therefore, from... Figure 3 It can be seen that when using alkaline slurries with an alkaline additive NaOH or NH4OH at a weight ratio equal to or less than 0.05% relative to the component ratio, stability is improved at certain C-ratios, especially as the number of cycles increases.

[0092] Furthermore, in view of the above, it can be concluded that, compared with Example 1 and Figure 1 Compared to non-alkaline slurries, each of the coin cell cells produced from sample slurries 1-4 showed an improved discharge decay rate.

Claims

1. A sodium battery electrode coating material, comprising at least one electrode active material, at least one binder, at least one alkaline additive, and optionally at least one conductive agent. in, The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof.

2. A slurry composition for a sodium battery electrode, comprising at least one electrode active material, at least one binder, at least one alkaline additive, at least one solvent, and optionally at least one conductive agent, and in, The alkaline additive is selected from metal hydroxides, metal carbonates, metal bicarbonates, metal silicates, ammonia or ammonium hydroxide, metal amines, metal amides, metal hydrides, metal oxides, metal cyanides, or any combination thereof.

3. The sodium battery electrode coating material according to claim 1, or the slurry composition for a sodium battery electrode according to claim 2, wherein, The electrode active material is selected from cathode active material (CAM) or anodic active material (AAM), preferably anodic active material (AAM).

4. The sodium battery electrode coating material according to claim 1 or 3, or the slurry composition for a sodium battery electrode according to claim 2 or 3, wherein, The anode active material (AAM) includes hard carbon, glassy carbon, carbon black, or graphite, or any combination thereof, preferably including hard carbon.

5. The sodium battery electrode coating material according to any one of claims 1 or 3-4, or the slurry composition for a sodium battery electrode according to any one of claims 2 or 3-4, wherein, The cathode active material (CAM) comprises a sodium-containing compound; preferably, it comprises sodium metal, sodium-containing alloy, sodium-containing oxide, sodium-containing cyanide, or any combination thereof; preferably, it comprises sodium transition metal oxide, sodium transition metal cyanide, or any combination thereof; preferably, it comprises sodium transition metal cyanide having 6 cyano groups per chemical formula unit; preferably, it comprises Prussian blue (PB) or a derivative of Prussian blue analogue (PBA); preferably, it comprises Prussian white (PW).

6. The sodium battery electrode coating material according to claim 5, or the slurry composition for a sodium battery electrode according to claim 5, wherein, The transition metal of the sodium transition metal oxide or sodium transition metal cyanide is selected from manganese (Mn), iron (Fe), aluminum (Al), titanium (Ti), nickel (Ni), vanadium (V), cobalt (Co) or any combination thereof. Preferably, the transition metal of the sodium transition metal oxide or sodium transition metal cyanide is selected from Fe-Fe, Mn-Fe, Fe-Ni, Ni or Co, more preferably Fe-Fe.

7. The sodium battery electrode coating material according to any one of claims 1 or 3-6, or the slurry composition for a sodium battery electrode according to any one of claims 2 or 3-6, wherein, The at least one adhesive is selected from styrene-butadiene rubber (SBR), polyacetylene, sodium lignosulfonate (NaLS), sodium alginate, guar gum, polyvinylidene fluoride (PVDF), sodium carboxymethyl cellulose (Na-CMC), polyacrylic acid (PAA) and sodium polyacrylate (PANa), polytetrafluoroethylene (PTFE), hexafluoropropylene (HFP), or any combination thereof; preferably, the at least one adhesive is sodium carboxymethyl cellulose (Na-CMC), styrene-butadiene rubber (SBR), or a combination thereof.

8. The sodium battery electrode coating material according to any one of claims 1 or 3-7, or the slurry composition for a sodium battery electrode according to any one of claims 2 or 3-7, wherein, The alkaline additive is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; alkali metal silicates; ammonia or ammonium hydroxide; amines or amides or oxides or cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium; or any combination thereof. Preferably, the metal is selected from alkali metal hydroxides; alkali metal carbonates; alkali metal bicarbonates; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof. More preferably, it is selected from alkali metal hydroxides; ammonia or ammonium hydroxide; cyanides of metals selected from the group consisting of alkali metals, alkaline earth metals, transition metals, aluminum, gallium, indium or thallium, each chemical formula unit having 1 to 4 cyano groups; or any combination thereof; Even more preferably, it is selected from alkali metal hydroxides, such as lithium hydroxide, sodium hydroxide, or potassium hydroxide; ammonia or ammonium hydroxide; or any combination thereof; or Most preferably, sodium hydroxide; ammonium hydroxide; or any mixture thereof.

9. The sodium battery electrode coating material according to any one of claims 1 or 3-8, or the slurry composition for a sodium battery electrode according to any one of claims 2 or 3-8, wherein, The alkaline additive is present in an amount of 0.0005% to 0.5% by weight of the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive of the electrode, preferably in an amount of 0.001-0.1% by weight of the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive of the electrode, preferably in an amount of 0.003-0.1%, 0.002-0.008%, 0.005-0.1%, 0.005-0.09%, 0.008-0.07%, 0.01-0.05%, or 0.015-0.04% by weight of the total weight of the electrode active material, binder, any conductive agent, and any alkaline additive of the electrode.

10. The sodium battery electrode coating material according to claim 8 or 9, or the slurry composition for a sodium battery electrode according to claim 8 or 9, wherein, The alkaline additive is selected from: • Sodium hydroxide (NaOH), provided in an amount of 0.01-0.04% by weight, preferably 0.015-0.035%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. Sodium carbonate (Na₂CO₃) is provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Sodium bicarbonate (NaHCO3), provided in an amount of 0.02-0.09% by weight, preferably 0.021-0.09% or 0.03-0.08%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Ammonium hydroxide (NH4OH), provided in an amount of 0.01-0.06% by weight, preferably 0.013-0.06% or 0.02-0.05%, based on the total weight of the electrode active material, binder, any conductive agent, and any alkaline additives of the electrode. • Any combination thereof.

11. The sodium battery electrode coating material according to any one of claims 1 or 3-10, or the slurry composition for a sodium battery electrode according to any one of claims 2 or 3-10, wherein, The at least one conductive agent is selected from carbon black, graphite, graphene, carbon nanotubes (CNTs) or any combination thereof; preferably, the at least one conductive agent is carbon black.

12. A process for producing a slurry composition for a sodium battery electrode according to any one of claims 2 or 3-10, comprising the following steps: a) Provide the at least one electrode active material. b) Provide the at least one adhesive. c) Optionally, the at least one conductive agent is provided. d) Provide the at least one solvent, e) Mix the electrode active material, the at least one binder, the at least one solvent, and the optional at least one conductive agent to obtain a slurry. f) Incorporate at least one alkaline additive into the slurry to increase the pH and provide the slurry composition.

13. A process for producing a sodium battery electrode coating material, comprising providing a slurry composition for a sodium battery electrode according to any one of claims 2 or 3-11, or a slurry composition for a sodium battery electrode obtained by the process according to claim 12. And further includes the following steps: g) Coating the slurry composition with an increased pH onto the current collector, and h) Dry the coated current collector to provide the sodium battery electrode coating material.

14. The process for producing sodium battery electrode coating material according to claim 13, wherein, The current collector is a metal foil, preferably an aluminum foil.

15. A process for manufacturing an electrode for a sodium-ion battery, comprising providing a sodium battery electrode coating material according to any one of claims 1 or 3-11, or a sodium battery electrode coating material obtained by the process according to claim 13 or 14, and further comprising the following steps: i) Calendered and dried coated current collector, and j) Optionally, the calendered current collector is cut.

16. An electrode for a sodium-ion battery, comprising a sodium battery electrode coating material according to any one of claims 1 or 3-11; or comprising a sodium battery electrode coating material obtained by a process for producing a sodium battery electrode coating material according to claim 13 or 14; or obtained by a process for manufacturing an electrode for a sodium-ion battery according to claim 15.

17. A method for manufacturing a sodium-ion battery cell, comprising the following steps: i. Providing at least one first electrode as described in claim 16 or obtained by the process described in claim 15. ii. Provide at least one second electrode with opposite electrical polarity, iii. Optionally, the at least one first electrode and the at least one second electrode are split. iv. Provide at least one diaphragm, v. Assembling the at least one first electrode, the at least one second electrode, and at least one diaphragm by stacking and / or winding. vi. Optionally, dry the assembled at least one first electrode, at least one second electrode, and at least one diaphragm. vii. Arrange the optionally dried and assembled at least one first electrode, at least one second electrode, and at least one separator in a battery case. viii. Fill the battery casing with electrolyte. ix. Seal the battery casing to form a battery cell.

18. The method for manufacturing a sodium-ion battery cell according to claim 17, wherein, The at least one first electrode is an anode, and the at least one second electrode is a cathode.

19. The method for manufacturing a sodium-ion battery cell according to claim 17 or 18, wherein, The diaphragm is selected from chemically stable and electrically insulating materials, preferably polyolefins such as polypropylene or polyethylene; cellulose; glass fiber; or any combination thereof.

20. A sodium-ion battery cell obtained by the method according to any one of claims 17-19.

21. Use of the electrode according to claim 16 in a sodium-ion battery.

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