Method of manufacturing a solid-state electrolyte film and battery comprising a solid-state electrolyte film

Abstract

The method for manufacturing the solid electrolyte thin film includes mixing a first precursor for synthesizing lithium lanthanum zirconium oxide, a second precursor for synthesizing lithium aluminum titanium phosphate or a third precursor for synthesizing lithium lanthanum titanium oxide, a polar solvent and a metal oxide containing a doping element to form a mixture. The first precursor includes a lithium source, a lanthanum source and a zirconium source, the second precursor includes a lithium source, an aluminum source, a titanium source and a phosphate, and the third precursor includes a lithium source, a lanthanum source and a titanium source. The mixture is ground to form a powder mixture. The powder mixture is calcined to form a doped powder. The doped powder, a lithium salt and a conductive polymer are mixed to form a slurry. A wet thin film is formed from the slurry. The wet thin film is baked. The solid electrolyte thin film can effectively reduce the interface impedance between the electrolyte and the positive and negative electrodes, and can have better charge and discharge performance when applied to a battery.

Description

Technical Field

[0001] This invention relates to a method for manufacturing battery materials and a battery containing such battery materials, particularly a method for manufacturing a solid electrolyte film and a battery containing a solid electrolyte film. Background Technology

[0002] The traditional lithium-ion battery structure consists of lithium anode and lithium iron phosphate (LiFePO4, LFP) cathode placed between the anode and cathode shells, respectively, with an electrolyte placed between the lithium anode and LFP cathode. Common cathode materials for lithium-ion batteries include lithium cobalt oxide, lithium manganese oxide, and lithium iron phosphate, while the primary anode material is graphite. However, graphite suffers from low specific capacity (theoretical capacity 372 mAh / g), making it unsuitable for future high-power and high-energy-density energy demands. Therefore, developing high-energy-density, high-cycle-life, safe, and non-toxic lithium-ion battery anode systems has become a key focus in energy storage development.

[0003] As traditional liquid electrolyte systems using lithium metal as the negative electrode have evolved towards higher energy levels, two major problems arise due to the uncontrollable deposition and dissolution of lithium ions at the negative electrode during charging and discharging. Firstly, the uneven deposition of lithium ions on the negative electrode can lead to dendritic structures that cause short circuits and other safety issues, or the formation of dead lithium. Secondly, the low coulombic efficiency results in the consumption of both lithium metal and electrolyte, leading to poor battery cycle life.

[0004] Therefore, all-solid-state electrolytes have been developed. Unlike liquid electrolytes, they lack the conductivity of liquid molecules and can be divided into solid-state inorganic ceramic electrolytes and polymer electrolytes, each with different ion conduction mechanisms. Solid-state inorganic ceramic electrolytes possess good thermal and electrical stability and generally exhibit good ionic conductivity. They are typically used in press-fit sheet form and polymer-blended thin film form. In these two application modes, the composite materials formed by the high hardness of solid electrolyte particles are often brittle and not resistant to compression. In addition, the lack of a liquid interface results in a relatively high interface impedance, which is also a problem that urgently needs to be improved. The atoms in the solid electrolyte structure are mostly fixed on the crystal lattice, and ion transfer is mainly achieved through energy differences created by lattice gaps or defects. Generally speaking, lithium ions at high temperatures increase their vibrational energy, increasing their probability of passing through defects and thus generating ion movement to complete the charge-discharge process. These vacancies can be widened by changing the doping of non-equivalent cations in the structure, thereby widening the lattice channels and allowing smaller lithium ions to move within the crystal at room temperature.

[0005] Generally speaking, solid inorganic ceramic electrolytes must meet the following conditions: (1) high concentration of mobile ions exist in the crystal structure, (2) a large number of vacant sites are available for mobile ions, (3) the potential energy of the mobile ions is close to that of the vacant sites they want to move to, (4) the activation energy barrier that the ions need to overcome when moving is low, (5) the solid structure is an open three-dimensional structure, and (6) polarizable anions.

[0006] Among them, LLZO(Li7La3Zr2O) 12 Lithium lanthanum zirconium oxide (LLZO) is an oxide solid electrolyte. Compared to other oxide solid electrolytes, LLZO exhibits high stability upon contact with lithium metal, and is therefore considered the most promising oxide solid electrolyte. However, LLZO has high impedance to lithium conductivity, making it difficult for lithium in the anode to migrate to the cathode.

[0007] Therefore, this case aims to propose a novel electrolyte material with high lithium mobility, thereby overcoming the aforementioned deficiencies in the prior art. Summary of the Invention

[0008] Therefore, the purpose of this invention is to solve the problems in the prior art mentioned above. This invention proposes a solid electrolyte thin film, a method for manufacturing the same, and a battery containing the solid electrolyte thin film. [The invention relates to] lithium lanthanum zirconium oxide (Li7La3Zr2O3) 12The process involves further adding doping elements, such as gallium, magnesium, aluminum, titanium, tantalum, niobium, scandium, yttrium, or hafnium, to lithium lanthanum zirconium oxide (LLZO), lithium aluminum titanium phosphate (LATP), or lithium lanthanum titanate (LLTO), and then mixing them with conductive polymers (e.g., polyethylene glycol (PEO), cellulose acetate, montmorillonite, vinylidene fluoride-co-hexafluoropropylene, or combinations thereof) and lithium salts to form a doped solid electrolyte film. The conductive polymers improve ionic conductivity. The solid electrolyte film produced in this invention effectively reduces the interface impedance between the electrolyte and the positive and negative electrodes, provides more pathways for lithium ion movement, and increases the lithium ion content, resulting in significantly improved electrochemical performance. Therefore, the electrolyte film exhibits high ionic conductivity and is highly suitable as a solid electrolyte material for batteries. This invention further allows for the placement of adhesive layers above and below the solid electrolyte film, eliminating air gaps between the solid electrolyte film and the anode and cathode above and below, thereby increasing ionic conductivity and reducing gaps generated during charging and discharging, thus lowering the internal ionic impedance and interphase impedance of the solid-state battery. Furthermore, the solid electrolyte film of this invention possesses sufficient toughness and hardness, reducing the probability of short circuits caused by direct puncture between the positive and negative electrodes due to negative electrode dendrites or hard forces, allowing it to be used directly as a solid electrolyte layer without the need for relatively fragile solid electrolyte ingots. The combination of the solid electrolyte film and the positive and negative electrode adhesives enables the solid electrolyte film of this invention to exhibit superior charge and discharge performance when applied to batteries.

[0009] To achieve the above objectives, the present invention proposes a method for manufacturing a solid electrolyte thin film, comprising the following operations: (A) Mixing a first precursor for synthesizing lithium lanthanum zirconium oxide (LLZO), a second precursor for synthesizing lithium aluminum titanium phosphate (LATP), or a third precursor for synthesizing lithium lanthanum titanium oxide (LLTO) with a polar solvent and a metal oxide containing the desired dopant element to form a mixture, wherein the first precursor includes a lithium source, a lanthanum source, and a zirconium source; the second precursor includes a lithium source, an aluminum source, a titanium source, and a phosphate; the third precursor includes a lithium source, a lanthanum source, and a titanium source; and the metal oxide includes gallium oxide, magnesium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, scandium oxide, yttrium oxide, or hafnium oxide. (B) Grinding the mixture to form a powder mixture. (C) Calcination of the powder mixture to form a doped powder. (D) Mixing the doped powder, lithium salt, and a conductive polymer with ion-conducting capabilities to form a slurry. (E) Forming a wet thin film from the slurry. (F) Baking the wet thin film to form a solid electrolyte thin film.

[0010] In some embodiments, the molar ratio of lithium to dopant elements in the doped powder is (6-7):(0.05-0.7), preferably (6-7):(0.3-0.5), and the dopant elements include gallium, magnesium, aluminum, titanium, tantalum, niobium, scandium, yttrium or hafnium.

[0011] In some embodiments, when the first precursor for the synthesis of lithium lanthanum zirconium oxide (LLZO), the polar solvent, and the metal oxide containing the doped element are mixed, the molar ratio of lithium source: lanthanum source: zirconium source: metal oxide is (6~7): (2.9~3.2): (2~2.1): (0.05~0.7), and the metal oxide is gallium oxide, magnesium oxide, or aluminum oxide.

[0012] In some embodiments, the manufacturing method further includes: grinding the doped powder before mixing the doped powder, lithium salt, and ion-conducting conductive polymer to form a slurry; and sintering the doped powder.

[0013] In some embodiments, the lithium salt includes lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)imide (LiTFSI), lithium difluoro(oxalato)borate (LiDFOB), or combinations thereof.

[0014] The present invention provides a solid electrolyte film, which is obtained by the manufacturing method described in any of the foregoing embodiments.

[0015] This invention also proposes a battery comprising a solid electrolyte film, including: a cathode, an anode, and a solid electrolyte film prepared by the manufacturing method described in any of the foregoing embodiments. The anode is located above the cathode. The solid electrolyte film is located between the cathode and the anode.

[0016] In some embodiments, the anode is lithium, and the cathode is lithium iron phosphate, lithium nickel manganese cobalt oxide (LNCM), lithium nickel manganese oxide (LNMO), lithium cobalt oxide (LCO), lithium manganite (LMO), or a combination thereof. In some embodiments, the cathode is a combination of two or more of the above materials.

[0017] In some embodiments, the battery further includes: a first adhesive layer disposed between the anode and the solid electrolyte film; and a second adhesive layer disposed between the cathode and the solid electrolyte film, wherein the first and second adhesive layers comprise polyvinylidene fluoride (PVDF), lithium salt, and poly(methyl methacrylate) (PMMA). In some embodiments, the lithium salt used is the same as described in the foregoing embodiments.

[0018] In some embodiments, the weight ratio of polyvinylidene fluoride, lithium salt, and polymethyl methacrylate is (1.2~1.5):(0.8~1):(0.3~0.7).

[0019] The features and advantages of the invention will be further understood from the following description, and please refer to the accompanying drawings while reading. Attached Figure Description

[0020] Figure 1A This diagram shows the steps involved in manufacturing the solid electrolyte film in this case.

[0021] Figure 1B This diagram shows the steps involved in manufacturing the doped LLZO solid electrolyte film in this case.

[0022] Figure 1C This diagram shows the steps involved in manufacturing the LATP-doped solid electrolyte film in this case.

[0023] Figure 1D This diagram shows the steps involved in manufacturing the doped LLTO solid electrolyte film in this case.

[0024] Figure 2AThis diagram shows an exploded view of the components of the first type of battery in this case.

[0025] Figure 2B This shows a test diagram of the first type of battery in this case.

[0026] Figure 3 This diagram shows an exploded view of the components of the second type of battery in this case.

[0027] Figure 4A This shows an exploded view of the components of a battery using LiTFSI+PEO.

[0028] Figure 4B show Figure 4A Test diagram of the battery.

[0029] Figure 5A This shows an exploded view of the components of a battery using LLZO+PEO.

[0030] Figure 5B show Figure 5A Test diagram of the battery. Detailed Implementation

[0031] The preferred embodiments of this invention are described in detail below with reference to the accompanying drawings, outlining the structural composition, effects, and advantages of the invention. For clarity, numerous practical details will be described in the following description. However, it should be understood that these practical details are not intended to limit the invention. In other words, these practical details are not essential in some embodiments of the invention. Furthermore, for the sake of simplicity, some conventionally used structures and elements will be illustrated in the drawings in a simplified schematic manner.

[0032] Please refer to Figures 1A to 3 As shown, this invention proposes a solid electrolyte film containing doped elements, a battery containing the same, and a method for manufacturing the same. The solid electrolyte film is used as the solid electrolyte in the battery, such as... Figure 2A and Figure 3 As shown.

[0033] (a) Methods for manufacturing solid electrolyte films (e.g.) Figure 1A (As shown)

[0034] Figure 1AThis diagram shows the steps involved in manufacturing the solid electrolyte film in this case. In step 110, a first precursor for synthesizing lithium lanthanum zirconium oxide, a second precursor for synthesizing lithium aluminum titanium phosphate, or a third precursor for synthesizing lithium lanthanum titanium oxide is mixed with a polar solvent and a metal oxide containing the desired dopant element to form a mixture. The first precursor includes a lithium source, a lanthanum source, and a zirconium source; the second precursor includes a lithium source, an aluminum source, a titanium source, and a phosphate; the third precursor includes a lithium source, a lanthanum source, and a titanium source; and the metal oxide includes gallium oxide, magnesium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, scandium oxide, yttrium oxide, or hafnium oxide. In some embodiments, the polar solvent includes methanol, ethanol, ethylene glycol, propanol, isopropanol, water, or combinations thereof.

[0035] In some embodiments, the metal in the first precursor, second precursor, or third precursor is a different metal from that in the metal oxide. In some embodiments, the lithium source includes lithium carbonate, lithium hydroxide, lithium bicarbonate, lithium nitrate, lithium acetate, lithium chloride, lithium hydrogen phosphate, lithium phosphate, or combinations thereof. In some embodiments, the lanthanum source includes lanthanum oxide, lanthanum hydroxide, or combinations thereof. In some embodiments, the zirconium source includes zirconium oxide, zirconium hydroxide, or combinations thereof. In some embodiments, the aluminum source includes aluminum oxide, aluminum hydroxide, aluminum nitrate, or combinations thereof. In some embodiments, the titanium source includes titanium oxide, titanium hydroxide, titanium chloride, orthotitanic acid, or combinations thereof. In some embodiments, the phosphate includes sodium phosphate, potassium phosphate, magnesium phosphate, or combinations thereof.

[0036] In some embodiments, the mixing method involves placing the precursor, polar solvent, and metal oxide containing the doped element into a ball mill jar, adding zirconium balls to form a mixed solution, and then ball milling using a ball mill tumbler. The ball mill tumbler includes zirconium balls and a zirconium ball agitator; when the agitator stirs, the zirconium balls impact the internal mixed solution, thoroughly dispersing it. In some embodiments, the ball milling rate is 200 to 300 rpm. In some embodiments, the ball milling time is 12 hours ± 20%. In some embodiments, the zirconium balls comprise zirconium oxide with a size between 0.3 mm and 0.15 mm.

[0037] In some embodiments, when the first precursor for synthesizing lithium lanthanum zirconium oxide (LLZO), the polar solvent, and the metal oxide containing the doped element are mixed, the molar ratio of lithium source: lanthanum source: zirconium source: gallium oxide is (6~7): (2.9~3.2): (2~2.1): (0.05~0.7) when the metal oxide is gallium oxide; the molar ratio of lithium source: lanthanum source: zirconium source: magnesium oxide is (6~7): (2.9~3.2): (2~2.1): (0.05~0.7) when the metal oxide is magnesium oxide; and the molar ratio of lithium source: lanthanum source: zirconium source: magnesium oxide is (6~7): (2.9~3.2): (2~2.1): (0.05~0.7) when the metal oxide is aluminum oxide.

[0038] In step 120, the mixture is ground to form a powder mixture. For example, the mixture is ground into a powder mixture using an agate mortar and pestle. In some embodiments, the mixture from step 110 is evaporated to dryness before step 120. In some embodiments, the evaporation temperature is 80°C to 120°C.

[0039] Step 130: Calcination of the powder mixture to form a doped powder. For example, the powder mixture is placed in a crucible and calcined in a high-temperature furnace while dry air or oxygen is introduced. In some embodiments, the doped powder has a cubic phase lattice. In some embodiments, the molar ratio of lithium to dopant elements in the doped powder is (6-7):(0.05-0.7), and the dopant elements include gallium, magnesium, aluminum, titanium, tantalum, niobium, scandium, yttrium, or hafnium. In some embodiments, the calcination temperature is 900°C ± 2%, and the calcination time is 10 hours ± 20%.

[0040] In step 140, the doping powder, lithium salt, and conductive polymer are mixed to form a slurry. In some embodiments, the conductive polymer includes polyethylene glycol, cellulose acetate, montmorillonite, vinylidene fluoride-co-hexafluoropropylene, or combinations thereof. In some embodiments, the lithium salt includes lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethanesulfonyl)amino (LiTFSI), lithium difluorooxalateborate (LiDFOB), or combinations thereof.

[0041] In some embodiments, the conductive polymer can be first mixed with a polar solvent to obtain a conductive polymer solution, wherein the polar solvent is as described above, preferably an anhydrous polar solvent, i.e., anhydrous methanol, anhydrous ethanol, anhydrous ethylene glycol, anhydrous propanol, anhydrous isopropanol, or a combination thereof. In some embodiments, step 140 includes the following operations: mixing polyethylene glycol and anhydrous ethanol, and heating and stirring with a heated stirrer until the polyethylene glycol is dissolved and uniformly mixed to form a polyethylene glycol solution; adding the doped powder and lithium salt to the polyethylene glycol solution to form a slurry; cooling the slurry; and stirring with a heated stirrer. In some embodiments, the stirring rate for heating and stirring with a heated stirrer until the polyethylene glycol is dissolved and uniformly mixed is 200 rpm ± 20%, and the stirring temperature is 80°C to 85°C. In some embodiments, the weight ratio of polyethylene glycol to the anhydrous ethanol is 3 to 5:1. In some embodiments, cooling the slurry includes cooling the slurry to 60°C ± 2%. In some embodiments, the stirring rate using a heated stirrer is 400 rpm ± 20%. In some embodiments, the mixing ratio of doped powder: conductive polymer (e.g., polyethylene glycol): lithium salt in the slurry is 1 ± 20 wt%: 1 ± 20 wt%: 1 ± 20 wt%. In some embodiments, the weight ratio of doped powder: conductive polymer (e.g., polyethylene glycol): lithium salt in the slurry is 1:1:1. In some embodiments, the particle size range of the doped powder is 300–500 nm.

[0042] In some embodiments, prior to step 140, the following operations are performed: grinding the doped powder; sintering the doped powder; placing the ground and sintered doped powder, a polar solvent (as described above), and zirconium balls into a ball mill jar, and ball milling using a ball milling machine to obtain a solution containing doped powder with fine particle sizes; evaporating the solution to dryness to obtain the doped powder; grinding the doped powder finely; and sieving it through a sieve. In some embodiments, the sintering temperature is 1100°C to 1200°C, and the sintering time is 6 hours ± 20%. In some embodiments, the ball milling rate is 200 to 300 rpm, and the ball milling time is 12 hours ± 20%. In some embodiments, the powder is sieved using a sieve with a mesh size of 300 to 500. In some embodiments, the evaporation temperature is 80°C ± 2%.

[0043] In step 150, a wet film is formed from the slurry. In some embodiments, step 150 includes: scraping the slurry onto a plastic substrate with a doctor blade to form a wet film. In some embodiments, the thickness of the wet film is 1000 μm ± 20%.

[0044] In step 160, the wet film is baked to form a solid electrolyte film. In some embodiments, the wet film is placed in a vacuum oven for baking and then cooled to room temperature to form a solid electrolyte film. In some embodiments, the baking temperature is 60°C ± 20%, and the baking time is 12 hours ± 20%.

[0045] (II) Methods for manufacturing doped LLZO powdered electrolytes (e.g.) Figure 1B (As shown)

[0046] In step 210, the precursors lithium carbonate (Li₂CO₃), lanthanum oxide (La₂O₃), zirconium oxide (ZrO₂), and ethanol are mixed with a metal oxide containing doped elements. The metal oxide includes gallium oxide (Ga₂O₃), magnesium oxide (MgO), aluminum oxide (Al₂O₃), titanium oxide (TiO₂), tantalum oxide (Ta₂O₅), niobium oxide (NbO), scandium oxide (Sc₂O₃), yttrium oxide (Y₂O₃), or hafnium oxide (HfO₂).

[0047] In one embodiment, when the metal oxide is gallium oxide (Ga2O3), the molar ratio of Li2CO3:La2O3:ZrO2:Ga2O3 is (6~7):(2.9~3.2):(2~2.1):(0.05~0.7).

[0048] In one embodiment, when the metal oxide is magnesium oxide (MgO), the molar ratio of Li2CO3:La2O3:ZrO2:MgO is (6~7):(2.9~3.2):(2~2.1):(0.05~0.7).

[0049] In one embodiment, when the metal oxide is aluminum oxide (Al2O3), the molar ratio of Li2CO3:La2O3:ZrO2:Al2O3 is (6~7):(2.9~3.2):(2~2.1):(0.05~0.7).

[0050] The mixing method involves placing the aforementioned precursor and metal oxide into a ball mill jar, adding ethanol and zirconium balls to form a mixed solution, and then ball milling using a ball mill tumbler. In some embodiments, the ball milling rate is 200 to 300 rpm, and the ball milling time is 12 hours ± 20%. In some embodiments, the ball mill tumbler includes multiple zirconium balls and a zirconium ball agitator. When the zirconium ball agitator stirs, the zirconium balls impact the internal mixed solution, thoroughly dispersing the solution; the previously agglomerated mixed solution is broken up by the impact of the zirconium balls. In some embodiments, the preferred size of the zirconium balls is between 0.3 mm and 0.15 mm, and the zirconium balls are made of zirconium oxide.

[0051] In step 220, after grinding with zirconium balls, the mixed solution is evaporated to dryness and then ground into powder using an agate mortar. In some embodiments, the evaporation temperature is 80°C to 85°C.

[0052] In step 230, the ground powder is placed in a crucible and calcined in a high-temperature furnace while dry air or oxygen is introduced. In some embodiments, the calcination temperature is 900℃±2%, and the calcination time is 10 hours±20%. Depending on the type of dopant and conditions, different doped LLZO powders are formed, with a cubic (Cubic) lattice morphology, as follows.

[0053] When the dopant is gallium oxide (Ga2O3), the doped LLZO is Li 6.25 Ga 0.25 La3Zr2O 12 .

[0054] When the dopant is magnesium oxide (MgO), the doped LLZO is Li7La3Zr. 1.9 Mg 0.2 O 12 .

[0055] When the dopant is aluminum oxide (Al2O3), the doped LLZO is Li 6.4 Al 0.25 La3Zr2O 12 .

[0056] In step 235, the LLZO-doped powder is ground finely in an agate mortar and sintered in a high-temperature furnace. In some embodiments, the sintering temperature is 1100 to 1200°C, and the sintering time is 6 hours ± 20%.

[0057] In step 240, the obtained doped LLZO powder, ethanol, and zirconium balls are poured into a ball mill jar to form a solution, and ball milling is performed using a ball milling tumbler to obtain finer particles. In some embodiments, the ball milling rate is 200 to 300 rpm, and the ball milling time is 12 hours ± 20%.

[0058] In step 250, after grinding with zirconium balls, the solution is evaporated to dryness and finely ground with an agate mortar and pestle, then sieved through a sieve. In some embodiments, a sieve with a mesh size of 300-500 is used, wherein the evaporation temperature is 80°C ± 2%.

[0059] (III) Preparation of doped LLZO solid electrolyte films (e.g.) Figure 1B (As shown)

[0060] Step 410: Mix polyethylene glycol (PEO) and anhydrous ethanol. In some embodiments, the weight ratio of PEO to anhydrous ethanol is 3~5:1. Heat and stir with a heated stirrer until the PEO dissolves and is uniformly mixed to form a PEO solution. The stirring rate is 200 rpm ± 20%, and the stirring temperature is 80℃~85℃.

[0061] Step 420: Add the doped powder and lithium salt to the PEO solution to form a slurry and cool it down, then stir it using a heated stirrer. In some embodiments, the temperature is lowered to 60°C ± 2%, and the stirring rate is 400 rpm ± 20%, wherein the mixing ratio is doped LLZO:PEO:lithium salt = 1 ± 20%: 1 ± 20%: 1 ± 20%, with a preferred ratio of 1:1:1. In a preferred embodiment, the lithium salt is lithium bis(trifluoromethanesulfonyl)imide (LiTFSI). In a preferred embodiment, doped LLZO powder with a particle size range of 300~500 nm is taken from the doped LLZO powder and mixed.

[0062] Step 430: After the slurry is mixed evenly, the slurry is scraped onto the plastic substrate with a spatula to form a wet film, which is then placed in a vacuum oven for baking and cooled to room temperature. In some embodiments, the thickness of the wet film is 1000 μm ± 20%; the baking temperature of the vacuum oven is 60℃ ± 20%, and the baking time is 12 hours ± 20%.

[0063] Step 440: After drying the wet film, cool it to room temperature to form a solid electrolyte film. In some embodiments, the size of the LLZO-doped solid electrolyte film is 2.0096 cm². 2 The thickness is 100μm.

[0064] (iv) Preparation of LATP-doped solid electrolyte films (e.g.) Figure 1C (As shown)

[0065] In step 210', the precursors lithium carbonate (Li2CO3), aluminum oxide (Al2O3), titanium oxide (TiO2), phosphate, ethanol, and a metal oxide containing doped elements are mixed. The metal oxide includes gallium oxide, magnesium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, scandium oxide, yttrium oxide, or hafnium oxide. The mixing method involves placing the precursors and metal oxides into a planetary mixer and adding ethanol and zirconium balls to form a mixed solution. The solution is then ball-milled using a planetary mixer. In some embodiments, before ball milling using a planetary mixer, the mixed solution is pre-emulsified for 30 minutes using an emulsifier, and then pre-mixed in the planetary mixer for 30 minutes. In some embodiments, wet grinding is performed using 0.3 mm zirconium balls. The zirconium ball loading is 1.2 kg / L to 1.5 kg / L, the grinding time is 8 hours to 16 hours, and the grinding speed is 2800 rpm to 3100 rpm.

[0066] In step 220', the mixed solution is centrifuged to remove the supernatant, the precipitate is collected, the precipitate is evaporated to dryness, and the precipitate is ground into powder. In some embodiments, the centrifugation speed is 5000 rpm. In some embodiments, the precipitate is baked at 100°C to 120°C until completely dry. In some embodiments, the powder is sieved through a 200-mesh sieve.

[0067] In step 230', the ground powder is placed in a crucible and calcined in a high-temperature furnace while dry air or oxygen is introduced. Depending on the type of dopant and the conditions, different doped LATP powders are formed. In some embodiments, the calcination includes: heating to 300°C~350°C at 3°C / min and holding for 2 hours; heating to 800°C at 3°C / min and holding for 2 hours; or heating to 1100°C~1200°C at 3°C / min and holding for 8 hours~10 hours. In some embodiments, the flow rate of dry air or oxygen introduced is 4L / min~8L / min.

[0068] In step 240', the doped LATP powder is ground. In some embodiments, the doped LATP powder is ground by dry milling.

[0069] In step 250', the LATP powder is sieved through a screen. In some embodiments, it is sieved through a 200-mesh screen.

[0070] In step 260', wet grinding is performed using zirconium balls. In some embodiments, wet grinding is performed using 0.3 mm zirconium balls, with a zirconium ball loading of 1.2 kg / L to 1.5 kg / L, a grinding time of 4 hours to 16 hours, a grinding speed of 2800 to 3100 rpm, and a polar solvent.

[0071] Next, proceed to steps 410-440, as described above. Figure 1B The implementation of steps 410-440, which form an LATP solid electrolyte film, will not be described in detail here.

[0072] (V) Preparation of Doped LLTO Solid Electrolyte Thin Films

[0073] In step 210", the precursors lithium carbonate (Li2CO3), aluminum oxide (Al2O3), titanium oxide (TiO2), phosphate, ethanol, and a metal oxide containing doped elements are mixed. The metal oxide includes gallium oxide, magnesium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, scandium oxide, yttrium oxide, or hafnium oxide. The mixing method involves placing the precursors and metal oxides into a planetary mixer and adding ethanol and zirconium balls to form a mixed solution. The solution is then ball-milled using a planetary mixer. In some embodiments, before ball milling using the planetary mixer, the mixed solution is pre-emulsified for 30 minutes using an emulsifier, and then pre-mixed in the planetary mixer for 30 minutes. In some embodiments, wet grinding is performed using 0.3 mm zirconium balls. The zirconium ball loading is 1.2 kg / L to 1.5 kg / L, the grinding time is 8 hours to 16 hours, and the grinding speed is 2800 rpm to 3100 rpm.

[0074] In step 220", the mixed solution is centrifuged to remove the supernatant, the precipitate is collected, the precipitate is evaporated to dryness, and the precipitate is ground into powder. In some embodiments, the centrifugation speed is 5000 rpm. In some embodiments, the precipitate is baked at 100°C to 120°C until completely dry. In some embodiments, the powder is sieved through a 200-mesh sieve.

[0075] In step 230", the ground powder is placed in a crucible and calcined in a high-temperature furnace while dry air or oxygen is introduced. Depending on the type of dopant and the conditions, different doped LATP powders are formed. In some embodiments, calcination includes heating to 1300°C~1400°C at a rate of 3°C / min and holding at that temperature for 12 hours.

[0076] In step 240", the doped LLTO powder is ground. In some embodiments, the doped LLTO powder is ground by dry milling.

[0077] In step 250", the LLTO powder is sieved through a screen. In some embodiments, it is sieved through a 200-mesh screen.

[0078] In step 260", wet grinding is performed using zirconium balls. In some embodiments, wet grinding is performed using 0.3 mm zirconium balls with a zirconium ball loading of 1.2 kg / L to 1.5 kg / L, a grinding time of 4 hours to 16 hours, a grinding speed of 2800 to 3100 rpm, and a polar solvent.

[0079] Next, proceed to steps 410-440, as described above. Figure 1B The implementation of steps 410-440 forms an LLTO solid electrolyte film, which will not be described in detail here.

[0080] Using the doped solid electrolyte thin film described above, batteries can be manufactured as follows. For example... Figure 2A As shown, the first type of battery includes: an anode shell 10, an anode 20, a solid electrolyte film 40, a cathode 60, a cathode shell 70, and a spring 80. In some embodiments, the anode 20 is lithium, and the cathode 60 is lithium iron phosphate (LiFePO4, LFP). The anode 20 is disposed between the anode shell 10 and the solid electrolyte film 40. The cathode 60 is disposed between the cathode shell 70 and the solid electrolyte film 40. In some embodiments, the solid electrolyte film 40 is a doped LLZO solid electrolyte film, a doped LATP solid electrolyte film, or a doped LLTO solid electrolyte film of any of the aforementioned embodiments. In some embodiments, the battery further includes: a spring 80 disposed between the anode shell 10 and the cathode shell 70 to increase the structural toughness. In some embodiments, the battery further includes: a spring 80 disposed between the anode shell 10 and the anode 20, but the present invention is not limited thereto, and the spring 80 can be disposed in other positions according to design requirements.

[0081] Figure 3This invention presents a second type of battery. In this case, adhesive layers can be disposed above and below the solid electrolyte membrane 40, eliminating air gaps between the solid electrolyte membrane 40 and the anode 20 and cathode LFP 60 above and below, thus increasing conductivity. Therefore, the second type of battery includes: an anode shell 10, an anode 20, a first adhesive layer 31, a second adhesive layer 32, a solid electrolyte membrane 40, a cathode 60, a cathode shell 70, and a spring 80. The anode 20 is located below the anode shell 10; the first adhesive layer 31 is disposed between the anode 20 and the solid electrolyte membrane 40; wherein the first adhesive layer 31 is a colloidal mixture containing polyvinylidene fluoride (PVDF), lithium salt, and poly(methylmethacrylate), PMMA. The PVDF has a high-strength structure. In some embodiments, the weight ratio of PVDF:lithium salt:PMMA is (1.2~1.5):(0.8~1):(0.3~0.7). A second adhesive layer 32 is disposed between the cathode 60 and the solid electrolyte film 40; wherein the material of the second adhesive layer 32 is the same as that of the first adhesive layer 31. The cathode shell 70 is located below the cathode LFP 60. In some embodiments, the battery further includes a spring 80 disposed between the anode shell 10 and the cathode shell 70 to increase structural toughness. In some embodiments, the battery further includes a spring 80 disposed between the anode shell 10 and the anode 20, but the invention is not limited thereto, and the spring 80 can be disposed in other positions according to design requirements.

[0082] The first adhesive layer 31 and the second adhesive layer 32 are prepared by placing a dimethylformamide (DMF) or tetrahydrofuran (THF) solvent in a planetary stirrer, and then adding a colloid of PMMA, PVDF, and lithium salt to the planetary stirrer for mixing. In some embodiments, the planetary speed is 500 rpm ± 20% and the rotation speed is 800 rpm ± 20%, and the stirring time is between 45 minutes and 1 hour, until the colloid becomes clear and transparent. The colloid is then dropped onto the upper and lower surfaces of the solid electrolyte film 40 and baked. In some embodiments, the baking temperature is 60°C ± 2%, and the baking time is 12 hours, so that the original DMF or THF solvent evaporates, thus forming a sandwich structure in which the first adhesive layer 31 and the second adhesive layer 32 cover the upper and lower surfaces of the solid electrolyte film 40. The advantage of this structure is that it allows the cathode, anode, and solid electrolyte film 40 to form an air-free sealed structure, thus having high conductivity, preventing short circuits, and possessing strong bonding force, making the entire structure more stable.

[0083] The following describes the first type of battery in this case and its differences from other batteries (such as...). Figure 4A and Figure 5A The differences are shown in the figure.

[0084] in Figure 4A For a battery using LiTFSI+PEO, an anode (negative electrode) lithium 20'' and a cathode (positive electrode) LFP (LiFePO4) 60'' are placed between the anode shell 10'' and the cathode shell 70'', respectively. Then, an electrolyte 30'' formed by mixing LiTFSI and PEO is placed between the anode 20'' and the cathode LFP 60''. In addition, a spring 80'' can be arranged between the anode shell 10'' and the cathode shell 70'' to increase the structural toughness. Figure 4B This displays a schematic diagram of the current / voltage versus time of the solid PEO polymer film in the LiTFSI+PEO battery at 65℃, with a charge / discharge rate of 0.1~1C and an operating range of 2.5V~3.7V (vs. Li / Li). + The PEO polymer film is 100 μm thick. The figure shows that the battery open-circuit voltage is less than 1V, and the voltage fluctuates irregularly during charging. This is presumably due to insufficient mechanical strength of the PEO polymer film, causing contact between the positive and negative electrodes, resulting in a short circuit and battery malfunction. Existing literature also indicates that the battery voltage becomes unstable during a short circuit, consistent with the experimental results.

[0085] in Figure 5A For a battery using LLZO+PEO, lithium anode (negative electrode) 20''' and lithium iron phosphate (LiFePO4, LFP) 60''' are placed between the anode shell 10''' and the cathode shell 70''', respectively. Then, an electrolyte 30''' formed by LLZO mixed with PEO is placed between the lithium anode 20''' and the lithium iron phosphate cathode 60'''. In addition, a spring 80''' can be arranged between the anode shell 10''' and the cathode shell 70''' to increase the structural toughness. Figure 5B The chart shows the test results for the LLZO+PEO battery. Because of the lack of LiTFSI, the ion conductivity is poor, resulting in a poor capacitance value. Lines 510, 520, 530, 540, and 550 represent the test results at 0.1C, 0.2C, 0.3C, 0.5C, and 1.0C, respectively.

[0086] Figure 2BThe following graphs show the charge-discharge curves of the first type of battery in this case at different rates. In the battery, a solid electrolyte film doped with LLZO is used as the solid electrolyte film 40, the anode 20 is lithium, and the cathode 60 is lithium iron phosphate. Curves 310, 320, 330, and 340 show the test results at 0.1C, 0.2C, 0.3C, and 0.5C, respectively. At 0.1C, the capacitance is approximately 110 mAh / g, and at 0.5C, it still retains a capacitance of 78 mAh / g. The solid-like film (i.e., solid electrolyte film 40) reduces the thickness of the electrolyte layer (900→100 μm), shortens the lithium-ion conduction distance, and the addition of lithium salt (LiTFSI) and doped LLZO (Li) to the film further enhances the performance. 6.25 Ga 0.25 La3Zr2O 12 ), lithium salt (LiTFSI) anion (TFSI) - It can combine with PEO side chains and dope LLZO (Li) 6.25 Ga 0.25 La3Zr2O 12 Powder can reduce the crystallinity of PEO and provide more pathways for lithium ion migration. The addition of lithium salt (LiTFSI) increases the lithium ion content in the solid film, resulting in a significant improvement in electrochemical performance.

[0087] In this case, doping with different elements has different effects on the phase transition temperature of the resulting doped LLZO. Specifically, the sample sintered at 1200℃ for 6 hours showed that Li... 6.25 Ga 0.25 La3Zr2O 12 Li7La3Zr whose phase transition temperature did not decrease 1.95 Mg 0.1 O 12 It possesses higher crystallinity and better lithium-ion conductivity. To increase the content of Li7La3Zr... 1.95 Mg 0.1 O 12 To maintain crystallinity, the sintering time must be extended. Impurity phases La₂Zr₂O₇ and Li₂ZrO₃ will form due to lithium loss. Gallium atoms are doped into LLZO(Li₇La₃Zr₂O₇). 12 Lithium lanthanum zirconium oxide (LCO) can effectively reduce the phase transition temperature (tetragonal → cubic), shorten the sintering time, and prevent lithium atoms from escaping during high-temperature sintering.

[0088] Traditionally, batteries using LLZO solid ceramic electrolytes suffer from high interfacial impedance between the electrolyte and the positive and negative electrodes, hindering the efficient movement of lithium ions within the battery. However, the solid electrolyte film 40 in this invention effectively reduces interfacial impedance, enabling lithium ions to transfer between the positive and negative electrodes and exhibiting superior battery electrochemical performance.

[0089] The advantage of this invention lies in the addition of doping elements to lithium lanthanum zirconium oxide (LLZO), lithium aluminum titanium phosphide (LATP), or lithium lanthanum titanium oxide (LLTO), followed by further mixing with conductive polymers and lithium salts to form a doped solid electrolyte film. The solid electrolyte film produced in this invention effectively reduces the interface impedance between the electrolyte and the positive and negative electrodes, provides more pathways for lithium ion movement, and increases the lithium ion content, resulting in significantly improved electrochemical performance. Therefore, it exhibits high lithium-ion conductivity, making it highly suitable as a solid electrolyte material for batteries. Furthermore, this invention allows for the placement of adhesive layers above and below the doped solid electrolyte film, eliminating air gaps between the film and the anode and cathode, thus increasing conductivity. Moreover, the doped solid electrolyte film possesses sufficient rigidity to prevent short circuits caused by the connection between the positive and negative electrodes, allowing it to be used directly as a solid electrolyte without the need for solid electrolyte ingots. Therefore, the doped solid electrolyte film of this invention exhibits superior charge and discharge performance when applied to batteries.

[0090] In conclusion, the thoughtful and human-centered design of this case is highly in line with actual needs. Its specific improvements over existing deficiencies represent a significant breakthrough compared to existing technologies, offering genuinely enhanced effectiveness, and is not easily achieved.

[0091] The foregoing detailed description pertains to a feasible embodiment of the present invention. However, this embodiment is not intended to limit the scope of the patent of the present invention. All equivalent implementations or modifications that do not depart from the spirit of the present invention should be included within the scope of the patent of this case.

[0092] [Symbol Explanation]

[0093] 10, 10'', 10''': Anode shell

[0094] 20: Anode

[0095] 20'', 20''': Lithium anode

[0096] 30'': Electrolytes

[0097] 31: First adhesive layer

[0098] 32: Second adhesive layer

[0099] 40: Solid electrolyte thin film

[0100] 60: Cathode

[0101] 60'', 60''': Cathode lithium iron phosphate

[0102] 70, 70'', 70''': Cathode shell

[0103] 80, 80'', 80''': Spring

[0104] 110, 120, 130, 140, 150, 160, 210, 210', 210”, 220, 220', 220”, 230, 230', 230”, 235, 240, 240', 240”, 250, 250', 250”, 260', 260”, 410, 420, 430, 440: Steps

[0105] 310, 320, 330, 340: Curves

[0106] 510, 520, 530, 540, 550: lines.

Claims

1. A method of manufacturing a solid-state electrolyte film, characterized by, comprising: mixing a first precursor for synthesizing lithium lanthanum zirconium oxide, a second precursor for synthesizing lithium aluminum titanium phosphorous or a third precursor for synthesizing lithium lanthanum titanium oxide, a polar solvent and a metal oxide containing a doping element to form a mixture, wherein the first precursor comprises a lithium source, a lanthanum source and a zirconium source, the second precursor comprises a lithium source, an aluminum source, a titanium source and a phosphate, the third precursor comprises a lithium source, a lanthanum source and a titanium source, and the metal oxide comprises gallium oxide, magnesium oxide, aluminum oxide, titanium oxide, tantalum oxide, niobium oxide, scandium oxide, yttrium oxide or hafnium oxide; grinding the mixture to form a powder mixture; calcining the powder mixture to form a doped powder; mixing a conductive polymer and a polar solvent to form a conductive polymer solution, the polar solvent comprising methanol, ethanol, ethylene glycol, propanol, isopropanol or a combination thereof; mixing the doped powder, a lithium salt and the conductive polymer solution to form a slurry; forming a wet film from the slurry; and baking the wet film to form the solid-state electrolyte film.

2. The manufacturing method of claim 1, wherein a molar ratio of lithium to the doping element in the doped powder is (6-7):(0.05-0.7), the doping element comprising gallium, magnesium, aluminum, titanium, tantalum, niobium, scandium, yttrium or hafnium.

3. The manufacturing method of claim 1, wherein the first precursor for synthesizing the lithium lanthanum zirconium oxide, the polar solvent and the metal oxide containing the doping element are mixed, wherein a molar ratio of the lithium source:the lanthanum source:the zirconium source:the metal oxide is (6-7):(2.9-3.2):(2-2.1):(0.05-0.7); and wherein the metal oxide is gallium oxide, magnesium oxide or aluminum oxide. further comprising: grinding the doped powder before mixing the doped powder, the lithium salt and the conductive polymer to form the slurry; and sintering the doped powder.

4. The production method according to claim 1, wherein 5. The manufacturing method of claim 1, wherein the lithium salt comprises lithium bisfluorosulfonylimide, lithium bis(trifluoromethylsulfonyl)amide, lithium difluoro oxalate borate or a combination thereof. comprising: a cathode; an anode positioned above the cathode; 6. A battery comprising a thin film of solid state electrolyte, characterized in that, the solid-state electrolyte film positioned between the cathode and the anode, the solid-state electrolyte film being a doped lithium lanthanum zirconium oxide solid-state electrolyte film, a doped lithium aluminum titanium phosphorous solid-state electrolyte film or a doped lithium lanthanum titanium oxide solid-state electrolyte film, the solid-state electrolyte film comprising a doping element, a lithium salt and a conductive polymer, the doping element comprising gallium, magnesium, aluminum, titanium, tantalum, niobium, scandium, yttrium or hafnium; a first adhesive layer positioned between the anode and the solid-state electrolyte film; and a second adhesive layer positioned between the cathode and the solid-state electrolyte film.

7. The battery of claim 6, wherein the anode is lithium and the cathode is lithium iron phosphate, lithium nickel cobalt manganese oxide, lithium nickel manganese oxide, lithium cobalt oxide, lithium manganese oxide or a combination thereof.

8. The battery of claim 6, wherein the first adhesive layer and the second adhesive layer comprise polyvinylidene fluoride, a lithium salt and polymethyl methacrylate.

9. The battery of claim 8, wherein a weight ratio of the polyvinylidene fluoride, the lithium salt and the polymethyl methacrylate is (1.2-1.5):(0.8-1):(0.3-0.7). ​ ​ ​

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