Lithium primary battery and method for manufacturing the same

Abstract

To provide a lithium primary battery and a manufacturing method thereof that extend the service life of the lithium primary battery and reduce its self-discharge.SOLUTION: A lithium primary battery includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode current collector, a positive electrode active coating disposed in order on at least one surface of the positive electrode current collector, and an electrolyte layer. The positive electrode active coating includes a positive electrode active material, a polymer solid electrolyte, an oxide solid electrolyte, and a lithium salt. The electrolyte layer includes a polymer solid electrolyte and a lithium salt.SELECTED DRAWING: None

Description

[Technical Field]

[0001] This application claims priority to a Chinese patent application filed with the China National Intellectual Property Office on May 23, 2024, with application number 2024106529417, and the entire contents of the said application are incorporated into this application by reference. This application relates to the technology of batteries, and more specifically to lithium primary batteries and methods for manufacturing the same. [Background technology]

[0002] The energy crisis and environmental problems caused by the continuous consumption and non-renewable nature of fossil fuels are becoming increasingly serious, and efficient and stable energy conversion and storage equipment is attracting attention. Lithium batteries have advantages such as high energy density, making them the most widely used electrochemical energy storage device, and they are widely used in various fields. Lithium primary batteries have great advantages such as excellent storage performance, stable discharge performance, and high energy density, and are widely used in fields such as military supplies and outdoor equipment. [Overview of the Initiative] [Problems that the invention aims to solve]

[0003] Conventional lithium primary batteries typically use organic liquids as electrolytes, but the flammability and corrosiveness of these organic electrolytes have significantly limited their practical application. Furthermore, the relatively small size of lithium primary batteries makes processes such as electrolyte injection difficult during production, leading to inconsistencies in the amount of electrolyte injected. This results in relatively low consistency and production yield of the final lithium primary batteries, which in turn affects their lifespan and self-discharge. [Means for solving the problem]

[0004] In the first aspect, the present application provides a primary lithium battery, which includes a positive electrode sheet and a negative electrode sheet. The positive electrode sheet includes a positive electrode current collector, a positive electrode active coating sequentially disposed on at least one surface of the positive electrode current collector, and an electrolyte layer. The positive electrode active coating includes a positive electrode active material, a polymer solid electrolyte, an oxide solid electrolyte, and a lithium salt. The electrolyte layer includes a polymer solid electrolyte and a lithium salt. The polymer solid electrolyte includes at least one of polyethylene oxide (PEO), polycarbonate (PPC), polyacrylonitrile (PAN), polysiloxane (PDMS), and polymethyl methacrylate (PMMA). The oxide solid electrolyte is Li 1.5 Al 0.5 Ge 1.5 (PO4)3 (LAGP), Li 1.4 Al 0.4 Ti 1.6 (PO4)3 (LATP), perovskite-type ceramic Li 0.33 La 0.557 TiO3 (LLTO), lithium lanthanum zirconium oxygen Li7La3Zr2O 12 (LLZO), and includes at least one of them.

[0005] In the second aspect, the present application provides a method for manufacturing a primary lithium battery, Step S1 of preparing a mixed solution by using a polymer solid electrolyte and an oxide solid electrolyte and mixing them with a solvent; Step S2 of preparing a positive electrode slurry by using a positive electrode active material and mixing it with a conductive agent, a binder, and a solvent; Step S3 of uniformly mixing the above mixed solution, the above positive electrode slurry, and a lithium salt, and applying them to at least one surface of a positive electrode current collector to form a positive electrode active coating; Step S4 of preparing an electrolyte solution by using a polymer solid electrolyte and a lithium salt and mixing them with a plasticizer and a solvent. Step S5 of applying the electrolyte solution to the surface of the positive electrode active coating to form an electrolyte layer and manufacturing a positive electrode sheet; Step S6 of assembling the positive electrode sheet and the negative electrode sheet to manufacture a primary lithium battery, and includes The polymer solid electrolyte comprises at least one of polyethylene oxide, polycarbonate, polyacrylonitrile, polysiloxane, polyvinylidene fluoride, and polymethyl methacrylate. Oxide solid electrolytes include Li 1.5 Al 0.5 Ge 1.5 (PO4)3, Li 1.4 Al 0.4 Ti 1.6 (PO4)3, Li 0.33 La 0.557 TiO3, Li7La3Zr2O 12 Includes at least one of the following: beneficial effects

[0006] (1) In this invention, a polymer solid electrolyte and an oxide solid electrolyte are introduced into the positive electrode active coating of a positive electrode sheet, and an electrolyte layer containing a polymer solid electrolyte is compounded onto the surface of the positive electrode active coating, thereby enabling the use of the positive electrode sheet in a lithium primary battery. On the other hand, the lithium primary battery is a solid-state battery, eliminating the injection process, improving the safety and energy density of the lithium primary battery, while simultaneously solving the problem of injection difficulties that occur in the manufacturing process of conventional lithium primary batteries, thereby improving production efficiency. On the other hand, the positive electrode active coating contains a polymer solid electrolyte, an oxide solid electrolyte and a lithium salt simultaneously, and the electrolyte layer installed on the surface of the positive electrode active coating contains a polymer solid electrolyte. By simultaneously introducing a polymer solid electrolyte into the positive electrode active coating of the positive electrode sheet and the electrolyte layer compounded onto the surface of the positive electrode active coating, the interfacial compatibility between the electrolyte layer and the electrode can be effectively improved, thereby enabling the electrolyte layer to adhere closely to the electrode, extending the service life of the lithium primary battery, and reducing the self-discharge of the lithium primary battery.

[0007] (2) In the method for manufacturing a primary lithium battery according to the present application, a positive electrode slurry containing a polymer solid electrolyte and an oxide solid electrolyte is applied to the surface of a positive electrode current collector to form a positive electrode active coating. Subsequently, an electrolyte solution containing a polymer solid electrolyte is applied to the surface of the positive electrode active coating to form an electrolyte layer. The manufactured positive electrode sheet and negative electrode sheet are assembled. Here, the electrolyte layer is tightly bonded to the positive electrode active coating in the positive electrode sheet and the negative electrode sheet, thereby extending the service life of the primary lithium battery, reducing the self-discharge of the primary lithium battery, and omitting the injection process in the manufacturing process of the above primary lithium battery, effectively solving the problem of injection difficulty occurring in the manufacturing process of the conventional primary lithium battery, and improving the production efficiency.

Embodiments for Carrying Out the Invention

[0008] In some embodiments, the thickness of the positive electrode active coating is 50 to 150 μm.

[0009] In some embodiments, the thickness of the electrolyte layer is 6 to 30 μm.

[0010] In some embodiments, the polymer solid electrolyte is PEO and the oxide solid electrolyte is LATP.

[0011] In some embodiments, the positive electrode active material is manganese dioxide, CF x (0.5 < x ≤ 1) includes at least one of them.

[0012] In some embodiments, the positive electrode current collector is an aluminum foil coated with carbon.

[0013] By using an aluminum foil coated with carbon as the positive electrode current collector, its conductivity is better, and at the same time, the contact interface between the aluminum foil and the positive electrode active coating can be improved, the adhesion between the positive electrode active coating and the aluminum foil is increased, further improving the energy density of the primary lithium battery and extending the service life of the primary lithium battery.

[0014] In some embodiments, the positive electrode active coating further includes a conductive agent and a binder. The conductive agent includes at least one of graphite, carbon nanotubes, acetylene black, and conductive carbon black. The binder includes at least one of polyvinylidene fluoride (PVDF) and polyvinylidene fluoride - hexafluoropropylene copolymer.

[0015] In some embodiments, in the positive electrode active coating, calculated by mass ratio, the positive electrode active material: polymer solid electrolyte: oxide solid electrolyte: lithium salt = 75 - 85:5 - 10:1 - 5:1 - 3.

[0016] In some embodiments, the conductive agent is manufactured by mixing carbon nanotubes and graphite in a mass ratio of 1 - 3:1 - 2.

[0017] In some embodiments, the negative electrode sheet is a lithium metal foil, and the thickness of the lithium metal foil is 30 - 80 μm.

[0018] In some embodiments, the above electrolyte layer further includes a plasticizer. The plasticizer includes at least one of succinonitrile, acetonitrile, and polyethylene glycol dimethyl ether. In the electrolyte layer, calculated by mass ratio, the polymer solid electrolyte: plasticizer: lithium salt = 40 - 80:5 - 10:20 - 60.

[0019] By introducing a plasticizer into the electrolyte layer, the ionic conductivity of the electrolyte layer can be further improved.

[0020] In some embodiments, in S1, the solid content of the mixed solution is 10 - 30%.

[0021] In some embodiments, the solvent includes at least one of N - methylpyrrolidone (NMP), dimethyl sulfoxide (DMSO), dimethylformamide (DMF), anisole, and p - xylene.

[0022] In some embodiments, the lithium salt is lithium hexafluoride phosphate (LiPF6), lithium tetraborate (LiBF4), lithium perchlorate (LiClO4), lithium hexafluoride arsenate (AsF6Li), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethane)sulfonimide (LiTFSI), lithium bis(oxalato)borate (C4BLi3O 11 ), and at least one of the following: lithium difluoro(oxalato)borate (LiODFB) and lithium bis(oxalato)borate (LiBOB).

[0023] In some embodiments, in the positive electrode active coating, the mass ratio calculated is positive electrode active material:conductive agent:binder:polymer solid electrolyte:oxide solid electrolyte:lithium salt = 75~85:3~4:2~3:5~10:1~5:1~3.

[0024] Example 1 Lithium primary batteries were manufactured using the following steps. S1. Under conditions of a temperature of 25±5℃ and a humidity of 65±5%, the polymer solid electrolyte PEO, the oxide solid electrolyte LATP, and the solvent NMP were pre-dehydrated until the water content of each component was ≤20 ppm, then uniformly mixed to prepare a mixed solution with a solid content of 20%. S2. Under conditions of a temperature of 25±5℃ and a humidity of 65±5%, the positive electrode active material manganese dioxide, conductive agent, binder PVDF, and solvent NMP were pre-dehydrated until the water content of each component was ≤20ppm. The binder PVDF and solvent NMP were then uniformly mixed to prepare a binder solution with a solid content of 7%. Next, the positive electrode active material manganese dioxide and conductive agent were dissolved in the binder solution, uniformly mixed, and prepared to obtain a positive electrode slurry. The conductive agent was manufactured by mixing carbon nanotubes and graphite in a 1:1 mass ratio. S3. After uniformly mixing the above mixture and the above positive electrode slurry, lithium salt LiTFSI was added and uniformly stirred. The mixture was then applied to both sides of the carbon-coated aluminum foil, which serves as the positive electrode current collector, and dried at a temperature of 90±5℃ for 24±2 hours to form a positive electrode active coating with a thickness of 100 μm on each side. In S1, S2, and S3, the mass ratio is calculated as follows: positive electrode active material: conductive agent: binder: polymer solid electrolyte: oxide solid electrolyte: lithium salt = 80:3.5:2.5:8:3:2. S4. Under conditions of a dew point temperature of 25±5℃ and humidity of 65±5%, the polymer solid electrolyte PEO, lithium salt LiTFSI, plasticizer acetonitrile, and solvent NMP were pre-dehydrated until the water content of each component was ≤20 ppm. After thoroughly mixing the polymer solid electrolyte PEO, lithium salt LiTFSI, and plasticizer acetonitrile, the solvent NMP was added and mixed uniformly to prepare the electrolyte solution. When calculated by mass ratio, the ratio of polymer solid electrolyte:plasticizer:lithium salt is 60:8:30. S5. The electrolyte solution was applied to the surface of the positive electrode active coating and dried at a temperature of 90±5℃ for 24±2 hours to form an electrolyte layer with a thickness of 15μm, thereby manufacturing a positive electrode sheet. S6. After cutting the positive electrode sheet, it is assembled with the lithium metal piece of the negative electrode sheet to manufacture a lithium primary battery, and the electrolyte layer is in close contact with the negative electrode sheet.

[0025] Example 2 Lithium primary batteries were manufactured using the following steps. S1. Under conditions of a temperature of 25±5℃ and a humidity of 65±5%, the polymer solid electrolyte PEO, the oxide solid electrolyte LATP, and the solvent NMP were pre-dehydrated until the water content of each component was ≤20 ppm, then uniformly mixed to prepare a mixed solution with a solid content of 10%. S2. Under conditions of a temperature of 25±5℃ and a humidity of 65±5%, the positive electrode active material manganese dioxide, conductive agent, binder PVDF, and solvent NMP were pre-dehydrated until the water content of each component was ≤20ppm. The binder PVDF and solvent NMP were then uniformly mixed to prepare a binder solution with a solid content of 7-10%. Next, the positive electrode active material manganese dioxide and conductive agent were dissolved in the binder solution, uniformly mixed, and prepared to obtain a positive electrode slurry. The conductive agent was manufactured by mixing carbon nanotubes and graphite in a mass ratio of 1:2. S3. After uniformly mixing the above mixture and the above positive electrode slurry, lithium salt LiTFSI was added and uniformly stirred. The mixture was then applied to both sides of the carbon-coated aluminum foil, which serves as the positive electrode current collector, and dried at a temperature of 90±5℃ for 24±2 hours to form a positive electrode active coating with a thickness of 150 μm on each side. In S1, S2, and S3, the mass ratio is calculated as follows: positive electrode active material: conductive agent: binder: polymer solid electrolyte: oxide solid electrolyte: lithium salt = 75:3:3:10:1:1. S4. Under conditions of a dew point temperature of 25±5℃ and humidity of 65±5%, the polymer solid electrolyte PEO, lithium salt LiTFSI, plasticizer acetonitrile, and solvent NMP were pre-dehydrated until the water content of each component was ≤20 ppm. After thoroughly mixing the polymer solid electrolyte PEO, lithium salt LiTFSI, and plasticizer acetonitrile, the solvent NMP was added and mixed uniformly to prepare the electrolyte solution. When calculated by mass ratio, the ratio of polymer solid electrolyte:plasticizer:lithium salt is 40:5:20. S5. The electrolyte solution was applied to the surface of the positive electrode active coating and dried at a temperature of 90±5℃ for 24±2 hours to form an electrolyte layer with a thickness of 6μm, thereby manufacturing a positive electrode sheet. S6. After cutting the positive electrode sheet, it is assembled with the lithium metal piece of the negative electrode sheet to manufacture a lithium primary battery, and the electrolyte layer is in close contact with the negative electrode sheet.

[0026] Example 3 Lithium primary batteries were manufactured using the following steps. S1. Under conditions of a temperature of 25±5℃ and a humidity of 65±5%, the polymer solid electrolyte PEO, the oxide solid electrolyte LATP, and the solvent NMP were pre-dehydrated until the water content of each component was ≤20ppm, then uniformly mixed to prepare a mixed solution with a solid content of 30%. S2. Under conditions of a temperature of 25±5℃ and a humidity of 65±5%, the positive electrode active material manganese dioxide, conductive agent, binder PVDF, and solvent NMP were pre-dehydrated until the water content of each component was ≤20ppm. The binder PVDF and solvent NMP were then uniformly mixed to prepare a binder solution with a solid content of 7-10%. Next, the positive electrode active material manganese dioxide and conductive agent were dissolved in the binder solution, uniformly mixed, and prepared to obtain a positive electrode slurry. The conductive agent was manufactured by mixing carbon nanotubes and graphite in a mass ratio of 3:1. S3. After uniformly mixing the above mixture and the above positive electrode slurry, lithium salt LiTFSI was added and uniformly stirred. The mixture was then applied to both sides of the carbon-coated aluminum foil, which serves as the positive electrode current collector, and dried at a temperature of 90±5℃ for 24±2 hours to form a positive electrode active coating with a thickness of 50 μm on both sides. In S1, S2, and S3, the mass ratio is calculated as follows: positive electrode active material: conductive agent: binder: polymer solid electrolyte: oxide solid electrolyte: lithium salt = 85:4:2:5:5:3. S4. Under conditions of a dew point temperature of 25±5℃ and humidity of 65±5%, the polymer solid electrolyte PEO, lithium salt LiTFSI, plasticizer acetonitrile, and solvent NMP were pre-dehydrated until the water content of each component was ≤20 ppm. After thoroughly mixing the polymer solid electrolyte PEO, lithium salt LiTFSI, and plasticizer acetonitrile, the solvent NMP was added and mixed uniformly to prepare the electrolyte solution. When calculated by mass ratio, the ratio of polymer solid electrolyte:plasticizer:lithium salt is 80:10:60. S5. The electrolyte solution was applied to the surface of the positive electrode active coating and dried at a temperature of 90±5℃ for 24±2 hours to form an electrolyte layer with a thickness of 30 μm, thereby manufacturing a positive electrode sheet. S6. After cutting the positive electrode sheet, it is assembled with the lithium metal piece of the negative electrode sheet to manufacture a lithium primary battery, and the electrolyte layer is in close contact with the negative electrode sheet.

[0027] Example 4 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing steps S1 and S4 of the lithium primary battery, the polymer solid electrolyte PEO was replaced with an equal amount of polymer solid electrolyte PPC. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are strictly the same as those in Example 1.

[0028] Example 5 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing steps S1 and S4 of the lithium primary battery, the polymer solid electrolyte PEO was replaced with an equal amount of polymer solid electrolyte PAN. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are in exact agreement with those of Example 1.

[0029] Example 6 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing steps S1 and S4 of the lithium primary battery, the polymer solid electrolyte PEO was replaced with an equal amount of polymer solid electrolyte PDMS. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are strictly the same as those in Example 1.

[0030] Example 7 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing step S4 of the lithium primary battery, the polymer solid electrolyte PEO was replaced with an equal amount of polymer solid electrolyte PVDF. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are strictly the same as those in Example 1.

[0031] Example 8 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing steps S1 and S4 of the lithium primary battery, the polymer solid electrolyte PEO was replaced with an equal amount of polymer solid electrolyte PMMA. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are strictly the same as those in Example 1.

[0032] Example 9 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing steps S1 and S4 of the lithium primary battery, the oxide solid electrolyte LATP was replaced with an equal amount of oxide solid electrolyte LAGP. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are strictly the same as those in Example 1.

[0033] Example 10 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing step S1 of the lithium primary battery, the oxide solid electrolyte LATP is replaced with an equal amount of oxide solid electrolyte LLTO. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are exactly the same as those in Example 1.

[0034] Example 11 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing step S1 of the lithium primary battery, the oxide solid electrolyte LATP is replaced with an equal amount of oxide solid electrolyte LLZO. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are exactly the same as those in Example 1.

[0035] Example 12 This embodiment provides a lithium primary battery. Compared to Example 1, the structural differences are: (1) in manufacturing step S3 of the lithium primary battery, the thickness of the manufactured positive electrode active coating is 40 μm; and (2) in manufacturing step S5 of the lithium primary battery, the thickness of the manufactured electrolyte layer is 3 μm. Aside from the above differences, the materials, mixing ratios, and manufacturing operations used in this embodiment are in exact agreement with those of Example 1.

[0036] Example 13 This embodiment provides a lithium primary battery. Compared to Example 1, the structural differences are: (1) in manufacturing step S3 of the lithium primary battery, the thickness of the manufactured positive electrode active coating is 180 μm; and (2) in manufacturing step S5 of the lithium primary battery, the thickness of the manufactured electrolyte layer is 40 μm. Aside from the above differences, the materials, mixing ratios, and manufacturing operations used in this embodiment are in exact agreement with those of Example 1.

[0037] Example 14 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing step S3 of the lithium primary battery, the positive electrode current collector is replaced with uncoated aluminum foil instead of carbon-coated aluminum foil. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are exactly the same as those in Example 1.

[0038] Example 15 This embodiment provides a lithium primary battery. Compared to Example 1, the structural difference is that in manufacturing step S4 of the lithium primary battery, the plasticizer was replaced with an equal amount of lithium salt. Aside from the above difference, the materials, mixing ratios, and manufacturing operations used in this embodiment are exactly the same as those in Example 1.

[0039] Example 16 This example provides a primary lithium battery. Compared with Example 1, the structural difference is that in the manufacturing step S2 of the primary lithium battery, manganese dioxide as the cathode active material is replaced with an equal amount of cathode active material CF x (0.5 < x ≤ 1). Except for the above differences, the materials, mixing ratios, and manufacturing operations used in this example are exactly the same as those in Example 1.

[0040] Comparative Example 1 This comparative example provides a primary lithium battery. Compared with Example 1, the structural difference is that in the manufacturing step S1 of the primary lithium battery, the oxide solid electrolyte LATP is replaced with an equal amount of polymer solid electrolyte PEO. Except for the above differences, the materials, mixing ratios, and manufacturing operations used in this comparative example are exactly the same as those in Example 1.

[0041] Comparative Example 2 This comparative example provides a primary lithium battery. Compared with Example 1, the structural difference is that in the manufacturing step S1 of the primary lithium battery, the polymer solid electrolyte PEO is replaced with an equal amount of oxide solid electrolyte LATP. Except for the above differences, the materials, mixing ratios, and manufacturing operations used in this comparative example are exactly the same as those in Example 1.

[0042] Comparative Example 3 This comparative example provides a primary lithium battery. Compared with Example 1, the structural differences are: (1) in the manufacturing step S1 of the primary lithium battery, the oxide solid electrolyte LATP is replaced with an equal amount of polymer solid electrolyte PEO; (2) in the manufacturing step S3 of the primary lithium battery, lithium salt LiTFSI is not included in the manufacturing process of the cathode active coating. Except for the above differences, the materials, mixing ratios, and manufacturing operations used in this comparative example are exactly the same as those in Example 1.

[0043] Test Example 1. Test Object In this test example, the primary lithium batteries manufactured according to Examples 1 to 16 and Comparative Examples 1 to 3 were used as the test objects, and relevant performance tests were carried out.

[0044] 2. Exam Content Battery self-discharge is an important parameter that characterizes the performance of lithium primary batteries. In this test, the self-discharge of lithium primary batteries was mainly tested using a static measurement method. Under predetermined environmental conditions (temperature 85°C, humidity 85%), lithium primary batteries were left standing for a long period of time, and the degree of battery self-discharge was evaluated by measuring the change in open-circuit voltage before and after the static period.

[0045] The annual self-discharge rate of lithium primary batteries was calculated using the following formula. The open-circuit voltage of the lithium primary battery was measured and recorded as V0 when the battery was fully charged before being left to stand. After being left to stand for 30 days under conditions of 85°C and 85% humidity, the open-circuit voltage of the lithium primary battery was measured and recorded as V1. The self-discharge rate of the lithium primary battery after 30 days of standing was calculated as η = [(V0 - V1) / V0] × 100%. The annual self-discharge rate was estimated or converted based on the self-discharge rate of the lithium primary battery after 30 days of standing.

[0046] 3. Experimental Results

[0047] Table 1 Test results of annual self-discharge rate of lithium primary batteries [Table 1]

[0048] Table 1 shows the relevant performance test results for the lithium primary batteries provided in Examples 1-16 and Comparative Examples 1-3.

[0049] The positive electrode active coating of the positive electrode sheet of the lithium primary battery provided in Examples 1-3 uses manganese dioxide as the positive electrode active material and incorporates a polymer solid electrolyte PEO, an oxide solid electrolyte LATP, and a lithium salt LiTFSI. Simultaneously, an electrolyte layer containing the polymer solid electrolyte PEO and lithium salt LiTFSI is compounded onto the surface of the positive electrode active coating. According to the test results, the annual self-discharge rate of the lithium primary battery provided in Examples 1-3 is only 2.0-2.5%, and this relatively low annual self-discharge rate can extend the service life of the lithium primary battery.

[0050] Compared to Example 1, the positive electrode active coating of the positive electrode sheet of the lithium primary battery provided by Comparative Example 1 does not contain the oxide solid electrolyte LATP, the positive electrode active coating of the positive electrode sheet of the lithium primary battery provided by Comparative Example 2 does not contain the polymer solid electrolyte PEO, and the positive electrode active coating of the positive electrode sheet of the lithium primary battery provided by Comparative Example 3 does not contain the oxide solid electrolyte LATP and the electrolyte layer does not contain lithium salt. The test results show that the annual self-discharge rates of the lithium primary batteries provided by Comparative Examples 1, 2, and 3 are all significantly higher than those of Example 1.

[0051] Compared to Example 1, the polymer solid electrolytes used in the positive electrode active coating and electrolyte layer of the positive electrode sheet of the lithium primary battery provided in Examples 4, 5, 6, and 8 were PPC, PAN, PDMS, and PMMA, respectively; the polymer solid electrolyte used in the electrolyte layer of the positive electrode sheet of the lithium primary battery provided in Example 7 was PVDF; and the oxide solid electrolytes used in the positive electrode active coating of the positive electrode sheet of the lithium primary battery provided in Examples 9, 10, and 11 were LAGP, LLTO, and LLZO, respectively. According to the test results, the annual self-discharge rates of the lithium primary batteries provided in Examples 4, 5, 6, 7, 8, 9, 10, and 11 were all higher than those of Example 1.

[0052] Compared to Example 1, the thickness of the positive electrode active coating on the positive electrode sheet of the lithium primary battery provided in Example 12 was <50 μm and the thickness of the electrolyte layer was <6 μm, while the thickness of the positive electrode active coating on the positive electrode sheet of the lithium primary battery provided in Example 13 was >150 μm and the thickness of the electrolyte layer was >30 μm. According to the test results, the annual self-discharge rates of the lithium primary batteries provided in Examples 12 and 13 were all higher than those of Example 1.

[0053] In comparison with Example 1, the positive electrode current collector used in the positive electrode sheet of the lithium primary battery provided in Example 14 is uncoated aluminum foil, and the positive electrode active material used in the positive electrode sheet of the lithium primary battery provided in Example 16 is CF x (0.5

Claims

1. A lithium primary battery comprising a positive electrode sheet and a negative electrode sheet, wherein the positive electrode sheet comprises a positive electrode current collector, a positive electrode active coating sequentially placed on at least one surface of the positive electrode current collector, and an electrolyte layer, the positive electrode active coating comprising a positive electrode active material, a polymer solid electrolyte, an oxide solid electrolyte, and a lithium salt, and the electrolyte layer comprising a polymer solid electrolyte and a lithium salt. The polymer solid electrolyte comprises at least one of polyethylene oxide, polycarbonate, polyacrylonitrile, polysiloxane, and polymethyl methacrylate. The oxide solid electrolyte is Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 、Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 、Li 0.33 La 0.557 TiO 3 、Li 7 La 3 Zr 2 O 12 A lithium primary battery containing at least one of these.

2. The thickness of the positive electrode active coating is 50 to 150 μm. and / or, The lithium primary battery according to claim 1, wherein the thickness of the electrolyte layer is 6 to 30 μm.

3. The polymer solid electrolyte is polyethylene oxide, and the oxide solid electrolyte is Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 The lithium primary battery according to claim 1.

4. The positive electrode active material is manganese dioxide, CF x A lithium primary battery according to claim 1, comprising at least one of the following (0.5 < x ≤ 1).

5. The lithium primary battery according to claim 1, wherein the positive electrode current collector is carbon-coated aluminum foil.

6. The lithium primary battery according to claim 1, wherein in the positive electrode active coating, when calculated by mass ratio, the positive electrode active material: polymer solid electrolyte: oxide solid electrolyte: lithium salt = 75-85:5-10:1-5:1-3.

7. The lithium primary battery according to claim 1, wherein the negative electrode sheet is a lithium metal piece.

8. The electrolyte layer further comprises a plasticizer, the plasticizer comprising at least one of succinonitrile, acetonitrile, and polyethylene glycol dimethyl ether. The lithium primary battery according to claim 1, wherein, in the electrolyte layer, the mass ratio of the polymer solid electrolyte:plasticizer:lithium salt is 40-80:5-10:20-60.

9. A method for manufacturing a lithium primary battery, Step S1 involves preparing a mixed solution by using a polymer solid electrolyte or an oxide solid electrolyte with a solvent, Step S2 involves preparing a conductive agent, binder, and solvent using the positive electrode active material to obtain a positive electrode slurry. Step S3 involves uniformly mixing the aforementioned mixture, the positive electrode slurry, and the lithium salt, and applying the mixture to at least one surface of the positive electrode current collector to form a positive electrode active coating. Step S4 involves preparing an electrolyte solution by using a polymer solid electrolyte and lithium salt with a plasticizer and solvent. Step S5 involves applying the electrolyte solution to the surface of the positive electrode active coating to form an electrolyte layer and manufacture a positive electrode sheet. The step includes assembling the positive electrode sheet and the negative electrode sheet to manufacture the lithium primary battery, step S6. The polymer solid electrolyte comprises at least one of polyethylene oxide, polycarbonate, polyacrylonitrile, polysiloxane, polyvinylidene fluoride, and polymethyl methacrylate. The oxide solid electrolyte is Li 1.5 Al 0.5 Ge 1.5 (PO 4 ) 3 Li 1.4 Al 0.4 Ti 1.6 (PO 4 ) 3 Li 0.33 La 0.557 TiO 3 Li 7 La 3 Zr 2 O 12 A method for manufacturing a lithium primary battery, comprising at least one of the following.

10. The method for manufacturing a lithium primary battery according to claim 9, wherein in S1, the solid content of the mixed liquid is 10 to 30%.

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