Positive electrode including discrete aluminum oxide nanomaterials and methods for the formation of aluminum oxide nanomaterials

Abstract

A positive electrode comprising: a lithium-based active material; a binder; a conductive filler; and discrete aluminum oxide nanomaterials, wherein the aluminum oxide nanomaterials are mixed over the entire positive electrode as an additive with the lithium-based active materials, the binder, and the conductive filler, wherein the aluminum oxide nanomaterials have a surface area of ​​at least 150 m² / g and wherein the aluminum oxide nanomaterials are present in an amount ranging from greater than 0 wt.% to 10 wt.% based on a total wt.% content of the positive electrode.

Description

BACKGROUND

[0001] Secondary or rechargeable lithium batteries are commonly used in many stationary and portable devices, such as those found in consumer electronics, automotive, and aerospace industries. Lithium batteries are gaining popularity for several reasons, including their relatively high energy density, the general absence of a memory effect compared to other rechargeable battery types, relatively low internal resistance, and low self-discharge rate when not in use. The ability of lithium batteries to undergo repeated restarts throughout their lifespan makes them an attractive and reliable power source. SUMMARY

[0002] In one example of a process disclosed herein, a solution is formed by mixing an aluminum oxide precursor and an acid. A carbon material is added to the solution to form an aqueous mixture containing the carbon material. A hydrothermal synthesis is carried out using the aqueous mixture, and precursor nanostructures are grown on the carbon material. The precursor nanostructures on the carbon material are annealed, causing the carbon material to be removed and aluminum oxide nanomaterials to be formed.

[0003] Examples of aluminum oxide nanomaterials can be used as additives in the positive electrodes of a lithium-ion battery. One example of a positive electrode comprises a lithium-based active material, a binder, a conductive filler, and discrete aluminum oxide nanomaterials. The aluminum oxide nanomaterials are mixed with the lithium-based active material, the binder, and the conductive filler as an additive within the positive electrode. BRIEF DESCRIPTION OF THE DRAWINGS

[0004] Features of examples of the present disclosure will become apparent by reference to the following detailed description and the drawings, in which the same reference numerals correspond to similar, though perhaps not identical, components. For the sake of brevity, reference numerals or features with a previously described function may or may not be described in conjunction with other drawings in which they appear.

[0005] Fig. 1A– Fig. Figure 1D are schematic and partially cross-sectional views that together represent several examples of the process for forming an example of the aluminium oxide nanomaterial disclosed herein;

[0006] Fig. Figure 2 is a cross-sectional view of an exemplary positive electrode on a current collector;

[0007] Fig. Figure 3 is a schematic perspective view of an exemplary lithium-ion battery, including an example of the positive electrode disclosed herein;

[0008] Fig. Figure 4 is a scanning electron microscope (“SEM”) image taken using a 4.29 µm scale of examples of the aluminum oxide nanomaterials formed from an example of the method disclosed herein;

[0009] Fig. Figure 5 is a transmission electron microscope (“TEM”) image taken using a 2 µm scale formed from examples of the aluminum oxide nanomaterials from an example of the method disclosed herein;

[0010] Fig. Figure 6 is a TEM image taken using a 50 nm scale of an example of one of the nanostructures extending radially outwards from the center of an aluminum oxide nanomaterial;

[0011] Fig. Figure 7 is a SEM image, using a 300 nm scale, of examples of aluminum oxide nanorods formed using a comparable method;

[0012] Fig. Figure 8 is a diagram showing the surface area (m²). 2 / g, left Y-axis) versus the potential hydrogen (pH) value (X-axis) for examples of aluminum nanorods from the comparable process and for examples of aluminum oxide nanomaterials formed from an example of the process disclosed herein; and

[0013] Fig. Figure 9 is a graph showing the output capacity (mAh / g, left Y-axis) versus the cycle count (X-axis) for an exemplary button cell showing a positive electrode with discrete aluminum oxide nanomaterials as an additive. DETAILED DESCRIPTION

[0014] Lithium-ion batteries generally operate by the reversible flow of lithium ions between a negative electrode (sometimes called the anode) and a positive electrode (sometimes called the cathode). The negative and positive electrodes are located on opposite sides of a porous polymer separator impregnated with an electrolyte solution suitable for conducting lithium ions. During charging, lithium ions are inserted (e.g., interposed, alloyed, etc.) into the negative electrode, and during discharging, lithium ions are extracted from the negative electrode. Each electrode is also connected to its associated current collectors, which are connected to an interruptible external circuit through which electric current can flow between the negative and positive electrodes.

[0015] In lithium-ion batteries, residual water contaminating the electrolyte can react with lithium salts, such as lithium hexafluorophosphate (LiPF6), to form hydrofluoric acid (HF). HF can react with both active and passive components of the battery, potentially limiting its lifespan. Reducing HF formation is beneficial for producing long-life lithium-ion batteries. Aluminum oxide can reduce HF formation by acting as an HF scavenger. Aluminum oxide can trap HF according to the following reaction (I): Al2O3 + 6HF → 2AlF3 + 3H2O (I) in which aluminum oxide can react with HF to form aluminum fluoride (AlF3) and water. The AlF3 product is thought to contribute to the stability of a solid electrolyte interphase (SEI).

[0016] In the positive electrode disclosed herein, discrete aluminum oxide nanomaterials are added as an additive. As used here, the term "discrete" means that the nanomaterials are detached structures that are not embedded in or coated onto the active material, the binder, the conductive filler, or other aluminum oxide nanomaterials. The additive is mixed with the active material, the binder, and the conductive filler in the positive electrode. The discrete aluminum oxide nanomaterials can extend the lifetime of lithium-ion batteries, at least in part by acting as RF scavengers. By scavenging RF, the discrete aluminum oxide nanomaterials can attenuate cathode / positive electrode transition metal dissolution (e.g., manganese, nickel, and cobalt), thereby reducing active material loss.Additionally, the reduced amount of dissolved transition metal ions that migrate to the anode / negative electrode can be reduced to pure metal nanoparticles at the anode. These pure metal nanoparticles can then catalyze the formation of solid electrolyte interphase (SEI) at the anode.

[0017] The aluminum oxide nanomaterials disclosed here can comprise a variety of nanostructures extending radially outward from a central point, resembling a sea urchin. The nanostructures can be interconnected at or near the center. The diameter of each nanostructure can decrease along its length away from the center. Small spaces (i.e., gaps) can separate one nanostructure from another within the arrangement.

[0018] Referring to the Fig. 1A– Fig. Section 1D discusses an example of the process for the formation of aluminum oxide nanomaterials. In one example, the process partially involves hydrothermal synthesis for the formation of the aluminum oxide nanomaterials.

[0019] Loud Fig. 1A will be an aqueous mixture 16 by mixing deionized water, an Al2O3 precursor 12 , an acid 14 and a carbon material 19 in a container 18 formed. The Al2O3 precursor 12 It could be aluminum chloride (AlCl3) or aluminum isopropoxide (Al(Oi-Pr)3). For example, 12 g of Al2O3 precursors could be... 12 for approximately 60 ml of aqueous mixture 16 be added. After the Al2O3 precursor 12 to the deionized water in the container 18 The added Al2O3 precursor 12The components can be dissolved by vigorous stirring. They can be mixed using a magnetic stirring rod, a hand-held stirring rod, or any other suitable aid known to those skilled in the art. The aqueous mixture 16 It can be mixed for a period of time ranging from approximately 5 minutes to approximately 2 hours. In one example, the aqueous mixture 16 Mixed for about 30 minutes.

[0020] The acid 14 The acid can be hydrochloric acid (HCl) (e.g., 1 M HCl), H₂SO₄, HNO₃, H₂PO₄, or any other suitable acid. 14 becomes an aqueous mixture 16 added until the mixture 16 has a desired pH value. The pH value of the mixture 16 can occur after adding the acid 14 in a range of approximately 1 to approximately 3.

[0021] The carbon material 19It can be exposed or dispersed in the deionized water. Any carbon material. 19 , which provides heterogeneous nucleation sites for Al2O3 and is inert during hydrothermal synthesis, can be used. In one example, the carbon material 19 lightly dispersed in the aqueous mixture 16 It exhibits a large surface area with many defects as heterogeneous nucleation sites and is easily removed after hydrothermal synthesis (e.g., by thermal oxidation). In one example, the carbon material is 19 Hollow carbon or graphite. Hollow carbon can be produced by thermally oxidizing carbon black. Some examples of suitable commercially available carbon black particles include VULCAN. ® XC72 (Cabot Corp.), KETJENBLACK ® (Akzo Nobel) and Black Pearl (BP2000) (Cabot Corp.). In one example, for each gram of the Al2O3 precursor 12, which is in the aqueous mixture 16 present, from approximately 0.8 mg to 2.5 mg of the carbon material 19 be added.

[0022] The carbon material 19 represents heterogeneous nucleation sites during the hydrothermal synthesis of the aqueous mixture 16 ready and thus facilitates the nucleation and growth of an Al2O3 precursor nanostructure 24 (see Fig. 1C). By providing heterogeneous nucleation sites during hydrothermal synthesis, it is assumed that the carbon material 19 provides a central structure from which the Al2O3 precursor nanostructure originates. 24 during the amplification phase, these Al2O3 precursor nanostructures can grow. 24 They grow radially outwards from the center. As such, the carbon material enables 19 the ultimately formed aluminum oxide nanomaterials 26 (see Fig. 1D) to assume a structure resembling a sea urchin, i.e., the individual nanostructures extend radially outwards from the center. Additionally, it is assumed that the carbon material 19 the yield of the Al2O3 precursor nanostructures 24 increased, and thus ultimately the yield of aluminum oxide nanomaterials 26 The edges and / or cavities of the carbon material 19 represent nucleation sites for the Al2O3 precursor nanostructure 24 ready.

[0023] With reference to Fig. 1B can be used after mixing the aqueous mixture 16 the aqueous mixture 16 to a closed system 20 to be added. In one example, the closed system 20 is an autoclave. Some examples of autoclaves include one coated with polytetrafluoroethylene (e.g., Teflon). ®-coated) or a copper-coated stainless steel autoclave. A TEFLON ® A copper-coated autoclave is used at temperatures below 200 °C. A copper-coated autoclave is used at temperatures of or above 200 °C.

[0024] The hydrothermal synthesis takes place in the closed system 20 as in Fig. 1B is shown. In particular, within the closed system 20 the aqueous mixture 16 The system is subjected to heat and vapor pressure for a certain period of time. The temperature of the heat ranges from approximately 150 °C to approximately 200 °C. The vapor pressure ranges from approximately 700 psi to approximately 1380 psi. The heat and vapor pressure are applied for a period of approximately 24 to 48 hours. For example, the temperature in the closed system can be... 20 The temperature will be raised to approximately 200 °C for 24 hours. It is assumed that the vapor pressure in the closed system will be...20 can reach 1,000 psi.

[0025] As mentioned above, the aqueous mixture contains 16 , which is subjected to hydrothermal synthesis, a water-soluble Al2O3 precursor 12 The application of heat and vapor pressure in the closed system 20 forms from the water-soluble Al2O3 precursor 24 an Al2O3 precursor nanostructure 12 In one example, the Al2O3 precursor nanostructure 24 an AlOOH leaf or thorn, attached to the carbon material 19 Several Al2O3 precursor nanostructures 24 are attached to the carbon material 19 attached and together forming the Al2O3 precursor nanostructures 24 A sea urchin-like nanomaterial. This sea urchin-like nanomaterial comprises many solid Al2O3 precursor nanostructures. 24 , which originate from the nucleation sites of the carbon material 19 have grown radially outwards.

[0026] As in Fig. As shown in Figure 1C, several Al2O3 precursor nanostructures are obtained after hydrothermal synthesis. 24 on a single particle of carbon material 19 grown up. It is assumed that at least some of the Al2O3 precursor nanostructures 24 , which were formed during hydrothermal synthesis, to the hollow carbon 19 are attached, as in Fig. 1C shown. Several Al2O3 precursor nanostructures. 24 can even grow from the same preferred site and can therefore be attached to other Al2O3 precursor nanostructures 24 They are attached. In these examples, the Al2O3 precursor nanostructures remain. 24 on the carbon material 19 attached, corresponding to the growth of the Al2O3 precursor nanostructures 24 The Al2O3 precursor nanostructures 24They place their growth in the sea urchin-like aluminum oxide nanomaterials 26 continued (shown in Fig. 1D).

[0027] In a specific example of the process, AlCl3 is the Al2O3 precursor. 12 and HCl is the acid 14 AlCl3 and 1 M HCl are added to deionized water to form an aqueous solution. In this example, 1 M HCl is added until the solution reaches a pH of 1.5. This example also includes hollow carbon, such as carbon material. 19 , added to the solution, thereby increasing the aqueous mixture 16 is formed. The carbon material 19 can be added before, during, or after the addition of the Al2O3 precursor 12 and / or the acid 14 to be added. It goes without saying that, since the hollow carbon 19 not with the Al2O3 precursor 12 or the acid 14He reacts at any time during the formation of the aqueous mixture. 16 can be added to the other components. Since the Al2O3 precursors 12 and the acid 14 which dissolve in the deionized water, can be dissolved before the addition of the carbon material. 19 and the formation of the aqueous mixture 16 A solution is formed. In the previously mentioned specific example, once the AlCl3 has dissolved, the solution has a pH of 1.5, and the hollow carbon contributes to the formation of the aqueous mixture. 16 When added, the aqueous mixture 16 into the closed system 20 , such as an autoclave. Heat and steam pressure are applied to the closed system. 20 for the formation of the sea urchin-like Al2O3 precursor nanostructures described previously 24 In this example, AlOOH is the formed Al2O3 precursor nanostructure. 24 .

[0028] It is to be understood that the aqueous mixture 16 (designated with 16’ in Fig. 1C) was modified after hydrothermal synthesis and at least the Al2O3 precursor nanostructure 24 This includes the organisms that have formed the sea urchin-like morphology described previously. At least a small amount of deionized water is present in the aqueous mixture. 16’ present. In some cases, other ions such as Cl may be present. – be present, even in concentrations that exceed the Al2O3 precursor nanostructures 24 will not affect it.

[0029] Following hydrothermal synthesis, the Al2O3 precursor nanostructures can be 24 then from the aqueous mixture 16’ They can be removed using any suitable separation technique. This allows the Al2O3 precursor nanostructures to be extracted. 24for example, they can be removed by vacuum filtration, centrifugation, or any suitable means. The Al2O3 precursor nanostructures 24 can be repeatedly treated with deionized water during and / or after the separation of the Al2O3 precursor nanostructures 24 from the aqueous mixture 16’ They must be washed. It may be desirable to remove the Al2O3 precursor nanostructures. 24 Wash with deionized water before applying the tempering process.

[0030] After separating the Al2O3 precursor nanostructures 24 from the aqueous mixture 16’ and the washing can remove the Al2O3 precursor nanostructures 24 They should be dried at a temperature range of approximately 60 °C to approximately 80 °C for a period of approximately 12 to 24 hours.

[0031] The dried Al2O3 precursor nanostructures 24Different examples of heat treatments for the formation of aluminum oxide nanomaterials can then be used. 26 are subjected to heat treatment. In one example, heat treatment is a tempering process (i.e., heating followed by slow furnace cooling) carried out in air or another oxygen-containing environment. The heat treatment can be applied for a period ranging from approximately 3 hours to approximately 8 hours at a temperature range of approximately 400 °C to approximately 800 °C. In one example, the heat treatment is applied at 550 °C for approximately 5 hours. During the heat treatment, the aluminum oxide nanomaterials are 26 formed. In particular, air acts as an oxidizing environment for the Al2O3 precursor nanostructures. 24 and thus forms the aluminum oxide nanomaterials 26 Additionally, the carbon material is further processed during heat treatment. 19 burned up, whereby the aluminum oxide nanomaterials26 in a sea urchin-like configuration / morphology (see Fig. 4 and Fig. 5).

[0032] In one example, the following reactions (II, III) take place between hollow carbon during heat treatment 19 and Al2O3 precursor nanostructures 24 for the formation of aluminum oxide nanomaterials 26 away: 2γ-AlOOH → γ-Al2O3 + H2O (II) C + O2 (from the air) → CO2↑ (III)

[0033] Al2O3 precursor nanostructures 24 They can be oxidized to form Al2O3 (reaction I). The hollow carbon burns as shown in reaction (II).

[0034] Examples of the morphologies of the final aluminum oxide nanomaterials 26 are in Fig. 4 and Fig. Figure 5 is shown. A description of how these nanomaterials were formed is given in the Examples section.

[0035] Fig. Figure 1D schematically illustrates each aluminum oxide nanomaterial. 26 Each of the nanostructures, extending radially outward from the center, has a diameter ranging from approximately 10 nm to approximately 200 nm. The length of each nanostructure ranges from approximately 80 nm to approximately 3 µm. The diameter of the nanostructures can decrease along their length, so that the nanostructure terminates in a point or exhibits a thorn-like structure. The aluminum oxide nanomaterials 26 exhibit a larger surface area compared to a metal oxide nanoparticle (which can be considered zero-dimensional, as it is essentially a point) or a metal oxide rod (which can be considered one-dimensional, as it is essentially a line). In one example, the surface area of ​​each of the aluminum oxide nanomaterials is 26 at least approximately 150 m 2 / g. In comparison, nanoparticles generally have a surface area greater than 0 m². 2 / g up to about 100 m 2 / g and nanorods generally have a surface area in the range of about 115 m² 2 / g up to about 150 m 2 / g. The larger surface area of ​​the aluminum oxide nanomaterials 26 It improves their ability to reduce HF formation. The aluminum oxide nanomaterials 26 They can absorb RF physically or chemically. The larger surface area of ​​the aluminum oxide nanomaterials 26 represents the aluminum oxide nanomaterials 26 with more absorbing sites, thus allowing for better reduction of HF in the electrolyte.

[0036] After receiving the aluminum oxide nanomaterials 26 Can the aluminum oxide nanomaterials 26They can be added as an additive to the positive electrode composition of a lithium-ion battery. In one example, discrete aluminum oxide nanomaterials are used. 26 added to the positive electrode composition. In another example, the aluminum oxide nanomaterials are used. 26 for positive electrode composition together with nanomaterials 26’ added, which are caused by the truncation (either intentionally or during the formation of the positive electrode composition) of some of the nanostructures extending from the center of the nanomaterials 26 extend radially outwards. The truncated nanostructures 26’ They tend to align laterally and are distributed essentially evenly throughout the composition. The positive electrode composition includes at least one active material. This is described in detail with reference to Fig. 2 described.

[0037] An example of the process for manufacturing a positive electrode 40 a lithium-ion battery 300 (see Fig. 3) will now be presented with reference to Fig. 2. Fig. Figure 2 shows an example of a positive electrode 40 with a lithium-based active material 28 , a binding agent 32 , a conductive filler 34 and the discrete aluminum oxide nanomaterials 26 as an additive on a carrier 30 .

[0038] In the examples for the production of the positive electrode 40 The aluminum oxide nanomaterials will be 26 dry with the lithium-based active material 28 and the conductive filler 34 mixed. In some cases, the binder is 32 also dry with the other components 26 , 28 , 34mixed. A solvent can then be added. In other cases, the binder is mixed. 32 and solvent mixed together and then added to the dry components 26 , 28 , 34 added. As described in more detail below, the solvent can be deionized water or an organic solvent, depending on the binder. 32 selected for the formation of a dispersion or mixture.

[0039] The lithium-based active material 28 can include any lithium-based active material that can be subjected to sufficient lithium insertion and disinsertion, while using aluminum or another suitable current collector. 30 as the positive terminal of the lithium-ion battery 300 (see Fig. 3) works. A common class of known lithium-based active materials that are suitable for this example of the positive electrode. 40Suitable materials include layered lithium transition metal oxides. This allows the lithium-based active material to be used in various applications. 28 for example, the spinel lithium manganese oxide (LiMn2O4), lithium cobalt oxide (LiCoO2), a manganese nickel oxide spinel [Li(Mn 1,5 Ni 0,5 )O2] or a layered nickel-manganese-cobalt oxide (with a general formula xLi2MnO3·(1 – x)LiMO2 or (M is composed in any ratio of Ni, Mn and / or Co). A specific example of the layered nickel-manganese-cobalt oxide includes (xLi2MnO3·(1 – x)Li(Ni) 1 / 3 Mn 1 / 3 Co 1 / 3 )O2). Other suitable lithium-based active materials include Li(Ni) 1 / 3 Mn 1 / 3 Co 1 / 3 )O2, Li x+y Mn 2-yO4 (LMO, 0 < x < 1 and 0 < y < 0.1) or a lithium iron polyanion oxide such as lithium iron phosphate (LiFePO4) or lithium iron fluorophosphate (Li2FePO4F), or a lithium-rich layered structure. Other lithium-based active materials can also be used, such as LiNi. 1-x Co 1-y M x+y O2 or LiMn 1,5-x Ni 0,5-y M x+y O4 (M is composed in any ratio of Al, Ti, Cr and / or Mg), stabilized lithium manganese oxide spinel (Li x Mn 2-y M y O4, where M is composed in a ratio of Al, Ti, Cr and / or Mg), lithium nickel cobalt aluminum oxide (e.g. LiNi 0,8 Co 0,15 Al 0,05 O2 or NCA), aluminum-stabilized lithium manganese oxide spinel (e.g. Li x Al 0,05 Mn 0,95O2), lithium vanadium oxide (LiV2O5), Li2MSiO4 (where M is composed of Co, Fe, and / or Mn in any ratio), and any other high-energy nickel-manganese-cobalt material (HE-NMC, NMC, or LiNiMnCoO2). "Any ratio" means that any element can be present in any quantity. Thus, in some examples, M could be Al, with or without Cr, Ti, and / or Mg, or any other combination of the listed elements. In another example, anion substitutions can be made in the lattice of any example of the lithium transition metal-based active material to stabilize the crystal structure. For example, any O atom can be substituted by an F atom.

[0040] The lithium-based active material 28 the positive electrode 40 can be used with the binder 32 , the conductive filler 34 and the aluminum oxide nanomaterials26 be mixed. The binder 32 Structurally holds the lithium-based active materials 28 and the conductive filler 34 together. Examples of binders 32 These include polyvinylidene fluoride (PVdF), polyethylene oxide (PEO), an ethylene propylene diene monomer (EPDM) rubber, carboxymethylcellulose (CMC), styrene-butadiene rubber (SBR), styrene-butadiene rubber-carboxymethylcellulose (SBR-CMC), polyacrylic acid (PAA), cross-linked polyacrylic acid-polyethyleneimine, polyimide, or any other suitable binder. Examples of other suitable binders include polyvinyl alcohol (PVA), sodium alginate, or other water-soluble binders.

[0041] The conductive filler 34 can be a conductive carbon material. The conductive carbon 34This could be a carbon with a large surface area, such as carbon black, or another carbon material (e.g., Super P). Other examples of suitable conductive fillers include... 34 These include graphene, graphite, carbon nanotubes and / or carbon nanofibers. The conductive filler 34 ensures electron conduction between the positive-side current collector 30 and the lithium-based active material 28 in the positive electrode 40 .

[0042] As described above, the aluminum oxide nanomaterials 26 Nanostructures that extend radially outwards from the center, resembling a sea urchin. Besides aluminum oxide nanomaterials. 26 The additive can be placed in the positive electrode. 40 also nanomaterials 26’ with a structure derived from the sea urchin 26 include the aluminum oxide nanomaterials. 26 and the nanomaterials 26’are not embedded in or coated on the other positive electrode components. In some examples, the aluminum oxide nanomaterials exhibit 26 a surface area of ​​at least 150 m² 2 / g. In one example, the aluminum oxide nanomaterials are 26 in a quantity ranging from greater than 0 wt.% to approximately 10 wt.% based on a total wt.% of the positive electrode 40 . available.

[0043] In an example of the process for manufacturing the positive electrode 40 The aluminum oxide nanomaterials will be 26 with the binder 32 , the conductive filler 34 and the lithium-based active materials 28 mixed. All these components can be mixed manually by dry mixing. After all these components have been combined, the components are mixed with water or organic solvent (depending on the binder used).32 ) to form the dispersion / mixture. In one example, the solvent is a polar aprotic solvent. Examples of suitable polar aprotic solvents are dimethylacetamide (DMAc), N-methyl-2-pyrrolidone (NMP), dimethylformamide (DMF), dimethyl sulfoxide (DMSO), or another Lewis base or combination thereof. If a water-soluble binder such as sodium alginate is used, the solvent can be water.

[0044] The dispersion / mixture can be mixed by milling. Milling helps convert the dispersion / mixture into a coatable slurry. Low- or high-shear milling can be used to mix the dispersion / mixture. The milling time for the dispersion / mixture ranges from approximately 10 minutes to 20 hours, depending on the shear rate. In one example, a rotary mixer is used for approximately 20 minutes at about 2000 rpm to mix the dispersion / mixture.

[0045] In one example of the dispersion / mixture, the amount of lithium-based active material is 28 from approximately 50 wt.% to approximately 95 wt.% (based on the total solid wt.% of the dispersion / mixture), the amount of conductive filler 34 The amount of binder ranges from approximately 5 wt.% to approximately 20 wt.% (based on the total solid wt.% of the dispersion / mixture). 32from approximately 5 wt.% to approximately 20 wt.% (based on the total solid wt.% of the dispersion / mixture) and the amount of aluminum oxide nanomaterials 26 ranges from greater than 0 wt.% to approximately 10 wt.% (based on the total solid wt.% of the dispersion / mixture).

[0046] The slurry is then applied to the carrier 30 isolated. In one example, the carrier 30 the positive-side current collector. It goes without saying that the carrier 30 The support may be made of aluminum or any other suitable electrically conductive material well known to those skilled in the art. 30 The selected electron generator should be able to collect free electrons and move them to and from an associated external circuit.

[0047] The slurry can be deposited using any suitable technique. For example, the slurry can be applied to the surface of the substrate. 30 can be cast or applied to the surface of the carrier 30 can be distributed or applied to the surface of the carrier 30 applied using a wide-slot coating machine.

[0048] The applied slurry can be subjected to a drying process to remove any remaining solvent and / or water. Drying can be achieved using any suitable technique. For example, drying can be carried out under ambient conditions (i.e., at room temperature, approximately 18°C ​​to 22°C, and one atmosphere). Drying can also be carried out at an elevated temperature in the range of approximately 60°C to approximately 150°C. In some cases, a vacuum can also be used to accelerate the drying process. As an example of the drying process, the applied slurry can be subjected to a vacuum at approximately 120°C for approximately 12 to 24 hours.

[0049] The drying process achieves the formation of the positive electrode. 40 In one example, the thickness of the dried slurry (i.e., positive electrode) is 40) from about 5 µm to about 200 µm. In another example, the thickness of the dried slurry (i.e., positive electrode) is 40 ) from approximately 10 µm to 100 µm.

[0050] During the formation of the positive electrode 40 The water and / or organic solvents are removed, and thus the resulting positive electrode contains 40 from approximately 50 wt.% to approximately 95 wt.% (based on the total wt.% of the positive electrode) 40 ) of the active material(s) 28 , from approximately 5 wt.% to 20 wt.% (based on the total wt.% of the positive electrode) 40 ) of the conductive filler 34 , from approximately 5 wt.% to 20 wt.% (based on the total wt.% of the positive electrode) 40 ) of the binder 32 , and from greater than 0 wt.% to approximately 10 wt.% (based on the total wt.% of the positive electrode) 40 ) of aluminum oxide nanomaterials 26 .

[0051] With reference to Fig. 3 is the lithium-ion battery 300 depicted. The in Fig. 3 lithium-ion batteries shown 300 includes the positive electrode 40 with the discrete aluminum oxide nanomaterials 26 as an additive.

[0052] As in Fig. As shown in section 3, the lithium-ion battery includes 300 in addition to the positive electrode 40 and the positive-side current collector 30 a negative electrode 38 , a negative-side current collector 36 and a porous separator 42 , which is between the positive electrode 40 and the negative electrode 38 is arranged.

[0053] In Fig. 3. The positive electrode 40 from any suitable lithium-based active material 28 be manufactured as before in relation to Fig. 2 described. As mentioned above, the lithium-ion-based active material can 28 with the binder 32 , the conductive filler 34 and the discrete aluminum oxide nanomaterials 26 be mixed.

[0054] The current collector 30 The positive side can be made of aluminum or any other suitable electrically conductive material known to a person skilled in the art.

[0055] The porous separator 42 in Fig. 3, which serves simultaneously as an electrical insulator and as a mechanical support, is located between the negative electrode 38 and the positive electrode 40 inserted to establish physical contact between the two electrodes 38 , 40 to prevent and avoid the occurrence of a short circuit. In addition to forming a physical barrier between the two electrodes. 38 , 40The porous separator represents 42 the passage of lithium ions (through the black dots and the open circles with a (+) charge in Fig. 3 marked) and associated anions (through the open circles with a (–) charge in Fig. 3 marked) by an electrolyte solution that fills its pores, ensuring safety. This ensures that the lithium-ion battery 300 works properly.

[0056] The porous separator 42The polyolefin membrane can be a homopolymer (derived from a single monomer component) or a heteropolymer (derived from more than one monomer component) and can be either linear or branched. If a heteropolymer derived from two monomer components is used, the polyolefin can adopt any copolymer chain arrangement, including block copolymers or random copolymers. The same applies if the polyolefin is a heteropolymer derived from more than two monomer components. For example, the polyolefin can be polyethylene (PE), polypropylene (PP), a mixture of PE and PP, or a multilayered structured porous film of PE and / or PP.

[0057] In other examples, the porous separator 42consisting of another polymer, selected from polyethylene terephthalate (PET), polyvinylidene fluoride (PVdF), polyamides (nylon), polyurethanes, polycarbonates, polyesters, polyetheretherketones (PEEK), polyethersulfones (PES), polyimides (PI), polyamide-imides, polyethers, polyoxymethylene (e.g., acetal), polybutylene terephthalate, polyethylene naphthenate, polybutene, polyolefin copolymers, acrylonitrile butadiene styrene copolymers (ABS), polystyrene copolymers, polymethyl methacrylate (PMMA), polyvinyl chloride (PVC), polysiloxane polymers (such as polydimethylsiloxane (PDMS)), polybenzimidazole (PBI), polybenzoxazole (PBO), polyphenylenes (e.g., PARMAX) TM (Mississippi Polymer Technologies, Inc., Bay Saint Louis, Mississippi)), polyaryletherketones, poly(perfluorocyclobutane), polytetrafluoroethylene (PTFE), polyvinylidene fluoride copolymers and terpolymers, polyvinylidene chloride, polyvinyl fluoride, liquid crystalline polymers (e.g., VECTRAN) TM (Hoechst AG, Germany) and ZENITE® (DuPont, Wilmington, DE) Poly(p-hydroxybenzene acid), polyaramides, polyphenylene oxide, and / or combinations thereof. In another example, the porous separator 42 selected from a combination of polyolefin (such as PE and / or PP) and one or more of the other polymers listed above.

[0058] The porous separator 42 It can be a single layer or a multi-layer laminate produced using either a dry or wet process. The entire separator 42 It can, for example, consist of a single layer of polyolefin and / or another listed polymer. Another example is the separator. 42 However, it can also be composed of several separate layers of the same or a different polyolefin and / or polymer. For example, the separator could be... 42The separator is formed by coating a separate layer of polyolefin with one or more layers of polymers. Furthermore, the polyolefin (and / or other polymer) layer and other optional polymer layers can also be formed within the separator. 42 may be contained as a fibrous layer to form the separator 42 to equip them with suitable structural and porosity characteristics. Other suitable separators are also needed. 42 They may contain a layer of ceramic material or a ceramic filler in the polymer matrix (i.e., an organic-inorganic composite matrix).

[0059] Any suitable electrolyte solution containing lithium ions between the negative electrode 38 and the positive electrode 40 can conduct electricity, can be found in the lithium-ion battery 300They can be used. In one example, the electrolyte solution can be an anhydrous liquid electrolyte solution, a lithium salt dissolved in an organic solvent, or a mixture of organic solvents. Experts are familiar with the many non-aqueous liquid electrolyte solutions used in lithium-ion batteries. 300The types of lithium salts that can be used are well-known, as are how they can be manufactured and purchased commercially. Examples of lithium salts that can be dissolved in an organic solvent to form the non-aqueous liquid electrolyte solution include LiClO4, LiAlCl4, LiI, LiBr, LiSCN, LiBF4, LiB(C6H5)4, LiCF3SO3, LiN(FSO2)2(LIFSI), LiN(CF3SO2)2(LiTFSI), LiAsF6, LiPF6, LiB(C2O4)2(LiBOB), LiBF2(C2O4), (LiODFB), LiPF4(C2O4)(LiFOP), LiNO3, and mixtures thereof. Suitable organic solvents include: cyclic carbonates (ethylene carbonate, propylene carbonate, butylene carbonate, fluoroethylene carbonate), linear carbonates (dimethyl carbonate, diethyl carbonate, ethyl methyl carbonate), aliphatic carboxylic acid esters (methyl formate, methyl acetate, methyl propionate), γ-lactones (γ-butyrolactone, γ-valerolactone), chain structure ethers (1,2-dimethoxyethane, 1,2-diethoxyethane, ethoxymethoxyethane), cyclic ethers (tetrahydrofuran, 2-methyltetrahydrofuran, 1,3-dioxolane) and mixtures thereof.

[0060] As in Fig. The lithium-ion battery shown in section 3 is included. 300 also an interruptible external circuit 46 , which is the negative electrode 38 and the positive electrode 40 connects them. The lithium-ion battery 300 A charger can also be used. 44 wear, which is operationally connected to the external circuit 46 can be connected. The charger 44 is driven by the electric current passing through the external circuit 46 flows when the lithium-ion battery 300 While the battery is being discharged, it is powered by electrical energy. 44 which can be any number of electrically powered devices, include some specific examples of a power-consuming charger. 44 An electric motor for a hybrid vehicle or an electric car, a laptop computer, a mobile phone, and a cordless power tool. The charger. 44However, it can also be an energy generation device that uses the lithium-ion battery. 300 to store the energy. The tendency of wind turbines or solar panels to generate electricity with fluctuations and / or interruptions, for example, often means that the excess energy must be stored for later use.

[0061] The lithium-ion battery 300 It can also include a variety of other components which, although not shown here, are well known to experts. The lithium-ion battery 300 It may, for example, contain a housing, seals, terminals, tabs and other useful components or materials that are placed between or around the negative electrode for performance or practical reasons. 38 and the positive electrode 40 are arranged. Additionally, the size and shape of the lithium-ion battery can be adjusted. 300as well as the design and chemical composition of their main components, depending on the specific application for which they were designed. Battery-powered automobiles and portable consumer electronics devices are two examples where the lithium-ion battery is used. 300 It would probably have a different size, capacity, and power output. The lithium-ion battery 300 It can also be connected in series and / or parallel with other similar lithium-ion batteries to produce a higher voltage output and current (in parallel connection) or a higher voltage output (in series connection) when the charger 44 This requires it.

[0062] The lithium-ion battery 300 It is generally based on the reversible passage of lithium ions from a negative electrode. 38 to a positive electrode 40and back again. When fully charged, the battery voltage is... 400 at a maximum value (usually in the range of 2.0 V to 5.0 V), while in a fully discharged state the battery voltage 300 at a minimum value (usually in the range of 0 V to 2.0 V). Essentially, the Fermi energy levels of the active materials in the positive and negative electrodes alternate. 40 , 38 During battery operation, and this also applies to the difference between the two, known as the battery voltage. During discharge, the battery voltage decreases and the Fermi levels approach each other. During charging, the reverse process occurs, with the battery voltage increasing while the Fermi levels move further apart. During battery discharge, the external load enables 44 a current flow in the external circuit 46, which has such a direction that the difference between the Fermi levels (and consequently the cell voltage) decreases. During battery charging, the opposite occurs: The battery charger forces a current flow in the external circuit. 46 , which has such a direction that the difference between the Fermi levels (and consequently the cell voltage) increases.

[0063] At the beginning of the discharge, the negative electrode contains 38 the lithium-ion battery 300 a high concentration of switched-on lithium, while the positive electrode 40 is relatively empty. If the negative electrode 38 If it contains a sufficiently high amount of stored lithium, the lithium-ion battery can 300 generate a usable electric current through reversible electrochemical reactions that occur when the external circuit is switched off. 46 is closed to connect the negative electrode 38and the positive electrode 40 to connect them together. Setting up the closed external circuit. 46 Under these circumstances, this causes the extraction of the stored lithium from the negative electrode. 38 The extracted lithium atoms are divided into lithium ions (marked by the black dots and the open circles with a (+) charge) and electrons (e – ) split, while leaving a storage host at the interface between the negative electrode and the electrolyte.

[0064] The chemical potential difference between the positive electrode 40 and the negative electrode 38 (in the range of approximately 2.0 V to approximately 5.0 V, depending on the exact chemical composition of the electrodes) 38 , 40 ) drives the electrons (e – ), which are caused by the oxidation of the intercalated lithium at the negative electrode 38arise from the external circuit 46 to the positive electrode 40 The lithium ions are simultaneously transferred from the electrolyte solution through the porous separator. 42 to the positive electrode 40 transported. The electrons (e – ), which is connected to the external circuit 46 flow and the lithium ions that pass through the porous separator 42 They migrate in the electrolyte solution, are eventually brought back together, and form embedded lithium at the positive electrode. 40 The electric current that flows through the external circuit 46 flows, can be used and through the charger 44 be directed until the level of stored lithium in the negative electrode 38 falls below a minimum level or there is no longer a need for electrical energy.

[0065] The lithium-ion battery 300It can be recharged after a partial or full discharge of its available capacity. To charge the lithium-ion battery 300 An external battery charger is connected to the positive and negative electrodes. 40 , 38 connected to repeat the electrochemical reactions of battery discharge in reverse order. During recharging, the electrons (e – ) back to the negative electrode 38 through the external circuit 46 and the lithium ions are transported through the electrolyte through the porous separator. 42 back to the negative electrode 38 transported. The electrons (e – ) and the lithium ions are attached to the negative electrode 38 The lithium is then recombined, allowing it to be stored again for use in the next battery discharge cycle.

[0066] The external battery charger that can be used to charge the lithium-ion battery 300 Charging can vary in size, construction, and specific end-use application of the lithium-ion battery. 300 They vary. Some suitable external battery chargers include a battery charger that plugs into an AC wall outlet and an automotive AC generator.

[0067] The large surface area (e.g., at least 150 m²) 2 / g) and the unique structure (e.g., with a multitude of nanostructures extending radially outwards from a hollow center, each nanostructure having a diameter in the range of about 10 nm to about 200 nm and a length of about 80 nm to about 3 µm) of the aluminum oxide nanomaterials 26 This makes them suitable for use in a variety of other applications. For example, aluminum oxide nanomaterials can be used... 26They are used in water purification. The aluminum oxide nanomaterials 26 They can remove ions from water (e.g., lead(II) and mercury(II)). The large surface area and distinct structure of aluminum oxide nanomaterials 26 It can provide a larger number of absorption sites for removing ions from the water. In another example, aluminum oxide nanomaterials can 26 It may also be suitable for use as a carrier material in drug administration.

[0068] Examples are given here to further illustrate the present disclosure. It is understood that these examples are provided for illustrative purposes and should not be interpreted as limiting the scope of the present disclosure. EXAMPLES Example 1

[0069] Six samples of aluminum oxide nanomaterials were produced. Samples 1–4 were produced using a comparable method. Samples 5 and 6 were produced using an example of the method disclosed herein.

[0070] Sample 1 was prepared by adding 5.4 grams of AlCl3 powder (i.e., 12 grams of AlCl3·9H2O) and 1 M HCl to deionized water. The AlCl3 powder was dissolved in deionized water. 1 M NaOH, acting as a pH adjuster, was added dropwise to the solution until a white hydrochloride precipitate formed and the desired pH was reached. The pH of this mixture was approximately 11. The mixture was transferred to a Teflon ®The aqueous mixture was placed in a coated stainless steel autoclave. The processing parameters for the hydrothermal synthesis included exposing the aqueous mixture to a temperature of 200 °C for approximately 24 to 48 hours. The pressure in the autoclave is assumed to have been approximately 1400 psi during the hydrothermal synthesis. At the end of the hydrothermal synthesis, the reaction product was removed from the autoclave, washed with deionized water, filtered under vacuum, and dried under vacuum at approximately 80 °C for approximately 12 to 24 hours.

[0071] The reaction product with the nanotubes was annealed in air at 550 °C for approximately 5 hours. During the heat treatment, the nanotubes sintered into nanorods, and water was produced as a byproduct and evaporated, forming three-dimensionally interconnected pores within the nanorods. The reaction during annealing was likely as follows: γ-AlOOH → γ-Al₂O₃ + H₂O. The porous γ-Al₂O₃ nanorods produced in Sample 1 exhibited a surface area of ​​approximately 120 m². 2 / g on.

[0072] Sample 2 was prepared using the same procedure as Sample 1 with the following variation. After adding the pH adjuster to the mixture, the pH was approximately 9. The porous γ-Al₂O₃ nanorods produced in Sample 2 had an average surface area of ​​approximately 130 m². 2 / g on.

[0073] Sample 3 was produced using the same procedure as Sample 1 with the following modification: After adding the pH adjuster to the mixture, the pH was approximately 5. The porous γ-Al₂O₃ nanorods produced in Sample 3 had an average surface area of ​​approximately 140 m². 2 / G.

[0074] Sample 4 was prepared using the same procedure as Sample 1 with the following modification: Al(Oi-Pr)3 was used as the precursor instead of AlCl3. The pH of this mixture was approximately 11. The porous γ-Al2O3 nanorods produced in Sample 4 had an average surface area of ​​approximately 120 m². 2 / g. Samples 1 to 4 illustrate that the AlCl3 powders and the Al(Oi-Pr)3 are very similar with respect to the surface area of ​​the final γ-Al2O3 nanorods formed.

[0075] A TEM image of the porous γ-Al2O3 nanorods produced in sample 1 was taken. This is shown in Fig. Figure 7 illustrates the one-dimensional dimensions.

[0076] Sample 5 was prepared according to an example of the process disclosed herein. An aqueous mixture was prepared by adding 12 g of AlCl3, 1 M HCl, and 10–30 mg of hollow carbon to 60 ml of deionized water. The aqueous mixture had a pH of 1.5.

[0077] The aqueous mixture was placed in a TEFLON ® The mixture was placed in a coated stainless steel autoclave. The processing parameters for the hydrothermal synthesis included exposing the aqueous mixture to a temperature of 200 °C for approximately 24 to 36 hours. The pressure in the autoclave is assumed to have been approximately 1400 psi during the hydrothermal synthesis. At the end of the hydrothermal synthesis, the reaction product was removed from the autoclave.

[0078] Following hydrothermal synthesis, the reaction product was filtered, washed, and dried to preserve the precursor nanostructure. The precursor nanostructure comprised the AlOOH sheets / spines arranged on the hollow carbon composite in a sea urchin-like nanostructure, with each AlOOH sheet having an average length ranging from 80 nm to approximately 3 µm and an average diameter ranging from approximately 20 nm to approximately 200 nm.

[0079] The sea urchin-like nanostructures with the hollow carbon composites were subjected to annealing at 550 °C for approximately 5 hours in air. During the heat treatment, the hollow carbon composites burned off, and the nanostructures sintered to form alumina nanomaterials with a sea urchin-like structure. Water was generated as a byproduct and evaporated. The reaction during annealing was likely the following: 2γ-AlOOH → γ-Al₂O₃ + H₂O. The alumina nanomaterials produced in sample 5 had a surface area of ​​approximately 240 m². 2 / G.

[0080] Sample 6 was produced using the same procedure as Sample 5, with the following variation: Graphite was used as the carbon material. The aluminum oxide nanomaterials produced in Sample 6 exhibited a surface area of ​​approximately 195 m². 2 / g on.

[0081] Comparing samples 5 and 6, the hollow carbon nanomaterial had a larger surface area and was more easily burned off during hydrothermal post-treatment. However, it is noted that the graphite-based nanomaterial had a larger surface area than any of samples 1–4.

[0082] A SEM image of the aluminum oxide nanomaterials produced in sample 5 was acquired. This image is in Fig. Figure 4 illustrates this. A TEM image of the aluminum oxide nanomaterials produced in sample 5 was also prepared. This is shown in Figure 4. Fig. 5 illustrates. Fig. 4 and Fig. Figure 5 clearly illustrates the sea urchin-like structure of the aluminum oxide nanomaterials. A TEM image was taken of one of the nanostructures, which extend radially outwards from the center of an aluminum oxide nanomaterial. This is shown in Fig. Figure 6 illustrates how the diameter of each nanostructure can decrease away from the center along the length of the nanostructure. Fig. Figure 8 shows a diagram of surface area (m²). 2 / g, left y-axis) versus pH value for samples 1–6. Example 2

[0083] The aluminum oxide nanomaterials of sample 5 were incorporated as an additive in two exemplary positive electrodes (A, A'). The exemplary positive electrodes comprised approximately 78% of a Li(Li) 0,2 Mn 0,54 Ni 0,13 Co 0,13The mixture consisted of O2 material as the active material, approximately 10% of a binder (PVdF), approximately 10% of a conductive filler (carbon black), and approximately 2 wt% of aluminum oxide nanomaterials. After mixing, most of the nanostructures extending radially outwards from the center were detached from the aluminum oxide nanomaterials. The detached nanostructures were deposited laterally and distributed essentially uniformly within the electrode.

[0084] A comparative positive electrode (B) contained all the same components as the positive electrode except for the aluminum oxide nanomaterials. The comparative positive electrode did not contain any aluminum oxide nanomaterials.

[0085] To form the positive example electrodes, the Li(Li)₂ was used. 0,2 Mn 0,54 Ni 0,13 Co 0,13 )O2 as active material, the soot and the aluminum oxide nanomaterials dry in a THINKY ®The mixture was mixed in a mixer. The PVdF and a solvent (NMP) were added to dry the mixture. To form the comparable electrode, the Li(Li)₂ was added. 0,2 Mn 0,54 Ni 0,13 Co 0,13 )O2 as active material and the soot dry in a THINKY ® The mixture was mixed in a mixer. PVdF and a solvent (NMP) were added to dry the mixture. The mixtures were blended until two relatively uniform, coatable slurries were formed. The slurries were poured onto the respective aluminum current collectors. The electrode coating and reference electrode coating were air-dried at room temperature, then oven-dried at approximately 80 °C for about 24 hours, and then vacuum-dried at approximately 100 °C for about 24 hours.

[0086] Each of the positive reference electrodes and positive example electrodes was used with a negative lithium foil electrode to form half-cells. Button cells (2032 hardware) were assembled inside an argon-filled glove box. Microporous three-layer polypropylene (PP) and polyethylene (PE) polymer membranes (CELGARD 2032, available from Celgard) were used as a separator. The electrolyte consisted of 1M LiPF6 in a solvent mixture such as ethylene carbonate (EC) and diethyl carbonate (DEC) in a volume ratio of 1:2.

[0087] The button cells were kept at 45 °C to perform galvanostatic cycling tests. The cycling tests were carried out at a rate of C / 3 and within the voltage window of 2.0 V to 4.6 V for at least 100 cycles.

[0088] Fig. Figure 9 shows the discharge capacity (mAh / g, Y-axis) versus the cycle count (X-axis) for the button cells, including the exemplary positive reference electrode (B) and the positive example electrodes (A, A') with the aluminum oxide nanomaterial additives. The discharge capacity (solid circles, A', and hole circles, A) of the example positive electrodes is much larger than the discharge capacity (solid squares, B) of the positive reference electrode because the cycle count has been increased to 30 or more.

[0089] As in Fig. As shown in Figure 9, the stability of the clocking during discharge improved when the positive electrode contained the aluminum oxide nanomaterials disclosed herein.

[0090] References in the description to "an example," "another example," "example," etc., mean that a specific element (e.g., feature, structure, and / or property) described in connection with the example is included in at least one example described here and may or may not be present in other examples. Furthermore, it is understood that the described elements for each example can be combined in any suitable way across the various examples, unless the context clearly dictates otherwise.

[0091] It is understood that the ranges provided here include the specified range and any value or subrange within that range. For example, a range from greater than 0 wt% to approximately 10 wt% should be interpreted to include not only the explicitly stated limits from greater than 0 wt% to approximately 10 wt%, but also individual values ​​such as 3.5 wt%, 6 wt%, 2 wt%, etc., and subranges such as from approximately 0.5 wt% to approximately 8 wt%, etc. Furthermore, when "approximately" is used to describe a value, it is meant to include minor variations (up to + / - 10%) of the specified value.

[0092] When describing and claiming the examples revealed here, the singular forms “ein”, “eine” and “der / die / das” imply plural references, unless the context clearly dictates otherwise.

[0093] Although several examples have been described in detail, it goes without saying that the disclosed examples can be modified. Therefore, the foregoing description should be considered non-restrictive.

Claims

[1] Positive electrode, comprising: a lithium-based active material; a binding agent; a conductive filler; and Discrete aluminum oxide nanomaterials, wherein the aluminum oxide nanomaterials are mixed over the entire positive electrode as an additive with the lithium-based active materials, the binder and the conductive filler. [2] Positive electrode according to claim 1, wherein the aluminium oxide nanomaterials have a surface area of ​​at least 150 m² 2 / g and wherein the aluminium oxide nanomaterials are present in an amount ranging from greater than 0 wt.% to about 10 wt.% based on a total wt.% content of the positive electrode. [3] Positive electrode according to claim 1, wherein the aluminium oxide nanomaterials are neither embedded nor applied in the lithium-based active material, the binder or the conductive filler. [4] Positive electrode according to claim 1, wherein: the lithium-based active material is present in an amount of approximately 50 wt.% to approximately 95 wt.% based on the total wt.% of the positive electrode; the binder is present in an amount of approximately 5 wt.% to approximately 20 wt.%, based on the total wt.% of the positive electrode; the conductive filler is present in an amount of approximately 5 wt.% to approximately 20 wt.%, based on the total wt.% of the positive electrode; and the aluminium oxide nanomaterials are present in an amount ranging from more than 0 wt.% to about 10 wt.%, based on the total wt.% of the positive electrode. [5] Positive electrode according to claim 1, wherein at least some of the aluminium oxide nanomaterials have nanostructures extending radially outwards from the center. [6] Lithium-based battery, comprising: a positive electrode, including: a lithium-based active material; a binding agent; a conductive filler; and discrete aluminum oxide nanomaterials, wherein the aluminum oxide nanomaterials are mixed as an additive with the lithium-based active material, the binder, and the conductive filler across the entire positive electrode; a negative electrode; and a microporous polymer separator impregnated with an electrolyte solution, wherein the microporous polymer separator is arranged between the positive electrode and the negative electrode. [7] Lithium-based battery according to claim 6, wherein: at least some of the aluminum oxide nanomaterials comprise nanostructures that extend radially outwards from the center; at least some of the aluminum oxide nanomaterials have a surface area of ​​at least 150 m² 2 / g include; and the aluminum oxide nanomaterials are present in an amount ranging from greater than 0 wt.% to approximately 10 wt.% based on the total wt.% of the positive electrode. [8] Procedures, comprehensive: Preparing a solution by mixing an aluminum oxide precursor and an acid; Adding a carbon material to the solution, thereby creating an aqueous mixture containing the carbon material; Performing hydrothermal synthesis using the aqueous mixture, thereby growing precursor nanostructures on the carbon material; and Glowing of the precursor nanostructures on the carbon material, thereby removing the carbon material and generating aluminum oxide nanomaterials. [9] The method of claim 8, wherein the aluminium oxide precursor is AlCl3 or Al(Oi-Pr)3, and wherein the solution has a potential pH in the range of about 1 to about 3. [10] Method according to claim 8, wherein the hydrothermal synthesis involves applying heat and vapor pressure to the aqueous mixture in a closed system, thereby generating growth of the precursor nanostructures from the carbon material radially outwards. [11] The method of claim 8, further comprising: Removal of the precursor nanostructures and any liquid from a closed system after hydrothermal synthesis prior to annealing the precursor nanostructures; wherein: The annealing of the precursor nanostructures is carried out by applying a heat treatment in an oxygen-containing environment in a temperature range of about 400 °C to about 800 °C for a time in the range of about 3 hours to 8 hours, whereby the aluminum oxide nanomaterials are formed; the carbon material is hollow carbon or graphite; and at least some of the aluminum oxide nanomaterials comprise nanostructures extending radially outwards from a center, and the method further comprises the truncation of at least some nanostructures extending radially outwards from the center. [12] The method of claim 8, further comprising: Dry mixing of the aluminum oxide nanostructures in a mixture, wherein the mixture comprises a lithium-based active material and a conductive filler; Adding a binder and a solvent to the mixture; Mixing the mixture to form a slurry; Applying the slurry to a carrier; and Drying the slurry. [13] Aluminium oxide nanomaterial comprising: a hole center; and a multitude of nanostructures extending radially outwards from the center of the hole, each nanostructure having a diameter ranging from about 10 nm to about 200 nm and a length ranging from about 80 nm to about 3 µm; wherein the aluminum oxide nanomaterial has a surface area of ​​at least 150 m² 2 / g