Lithium primary battery and manufacturing method thereof

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 from a Chinese patent application bearing application number 2024106529417, filed with the China Patent Office on May 23, 2024, the entire contents of which are incorporated herein by reference. This application relates to the field of batteries, and more particularly to lithium primary batteries and methods of making same. [Background technology]

[0002]

[0003] As the energy crisis and environmental problems caused by the continuous consumption and non-renewable nature of fossil energy become increasingly serious, attention is being paid to efficient and stable energy conversion and storage devices. Lithium batteries have advantages such as high energy density, making them the most widely used electrochemical energy storage device and are widely used in various fields. Lithium primary batteries have significant advantages such as excellent storage capacity, stable discharge performance, and high energy density, and are widely used in fields such as military equipment and outdoor gear. Summary of the Invention [Problem to be solved by the invention]

[0003] Conventional lithium primary batteries typically use organic liquids as electrolytes, but the practical application of lithium primary batteries is significantly limited due to problems such as the flammability and corrosiveness of organic electrolytes. Furthermore, during the production and manufacturing of lithium primary batteries, the relatively small size of the batteries makes it difficult to perform processes such as injection, and it is easy to inject too much or too little electrolyte, resulting in relatively low consistency and production yields for the final lithium primary batteries, which in turn affects the service life and self-discharge of the lithium primary batteries. [Means for solving the problem]

[0004] In a first aspect, the present application provides a lithium primary battery, the lithium primary battery including a positive electrode sheet and a negative electrode sheet, the positive electrode sheet including a positive electrode current collector, a positive electrode active coating disposed in that order on at least one surface of the positive electrode current collector, and an electrolyte layer, the positive electrode active coating including a positive electrode active material, a polymer solid electrolyte, an oxide solid electrolyte, and a lithium salt, the electrolyte layer including a polymer solid electrolyte and a lithium salt, the polymer solid electrolyte including at least one of polyethylene oxide (PEO), polycarbonate (PPC), polyacrylonitrile (PAN), polysiloxane (PDMS), and polymethyl methacrylate (PMMA), and the oxide solid electrolyte including 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 ceramic Li 0.33 La 0.557 TiO3 (LLTO), Lithium Lanthanum Zirconium Oxide Li7La3Zr2O 12 (LLZO)

[0005] In a second aspect, the present application provides a method for making a lithium primary battery, comprising: Step S1: preparing a mixed solution by using a polymer solid electrolyte and an oxide solid electrolyte and a solvent; Step S2 of preparing a positive electrode slurry by using a positive electrode active material, a conductive agent, a binder, and a solvent; Step S3: uniformly mixing the mixture, the positive electrode slurry, and the lithium salt, and applying the mixture to at least one surface of a positive electrode current collector to form a positive electrode active coating; Step S4 is to prepare an electrolyte solution by using a polymer solid electrolyte, a lithium salt, a plasticizer, and a solvent. Step S5: applying an electrolyte solution to the surface of the positive electrode active coating to form an electrolyte layer to produce a positive electrode sheet; Step S6 of assembling the positive electrode sheet and the negative electrode sheet to manufacture a lithium primary battery; the polymer solid electrolyte includes 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 (PO4)3, Li 1.4 Al 0.4 Ti 1.6 (PO4)3, Li 0.33 La 0.557 TiO3, Li7La3Zr2O 12 Contains at least one of the following:

[0006] (1) This application describes a method for applying a polymer solid electrolyte and an oxide solid electrolyte to a positive electrode active coating of a positive electrode sheet, and further forming an electrolyte layer containing the polymer solid electrolyte on the surface of the positive electrode active coating. This method uses the positive electrode sheet in a lithium primary battery. The lithium primary battery is a solid-state battery, eliminating the need for an injection process, improving the safety and energy density of the lithium primary battery while also successfully resolving the injection difficulties encountered in the manufacturing process of conventional lithium primary batteries and improving production efficiency. The positive electrode active coating simultaneously contains a polymer solid electrolyte, an oxide solid electrolyte, and a lithium salt, and the electrolyte layer formed on the surface of the positive electrode active coating comprises a polymer solid electrolyte. The simultaneous introduction of the polymer solid electrolyte into the positive electrode active coating of the positive electrode sheet and the electrolyte layer formed on the surface of the positive electrode active coating effectively improves the interfacial compatibility between the electrolyte layer and the electrode, thereby ensuring close contact between the electrolyte layer and the electrode, extending the service life of the lithium primary battery, and reducing 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) and 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, the energy density of the primary lithium battery is further improved, and the service life of the primary lithium battery is extended.

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

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

[0016] In some embodiments, the conductive agent is prepared 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 lithium metal foil has a thickness of 30 to 80 μm.

[0018] In some embodiments, the electrolyte layer further comprises a plasticizer, the plasticizer comprising at least one of succinonitrile, acetonitrile, and polyethylene glycol dimethyl ether, and the mass ratio in the electrolyte layer is 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 liquid is 10 to 30%.

[0021] In some embodiments, the solvent comprises 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 hexafluorophosphate (LiPF), lithium tetrafluoroborate (LiBF), lithium perchlorate (LiClO), lithium hexafluoroarsenate (AsFLi), lithium bis(fluorosulfonyl)imide (LiFSI), lithium bis(trifluoromethane)sulfonimide (LiTFSI), lithium bis(oxalato)borate (CBLiO ...oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium bis(oxalato)borate (CBLiO), lithium 11 ), lithium difluoro(oxalato)borate (LiODFB), and lithium bis(oxalato)borate (LiBOB).

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

[0024] Example 1 A lithium primary battery was fabricated by the following steps. S1. Under conditions of a temperature of 25±5°C and a humidity of 65±5%, the polymer solid electrolyte PEO, the oxide solid electrolyte LATP, and the solvent NMP were dehydrated in advance until the moisture content of each component was ≦20 ppm, and then uniformly mixed to prepare a mixed solution with a solid content of 20%. S2. Under conditions of a temperature of 25±5°C and a humidity of 65±5%, the positive electrode active material manganese dioxide, the conductive agent, the binder PVDF, and the solvent NMP were each dehydrated until the moisture content of each component was ≦20 ppm, and the binder PVDF and the solvent NMP were mixed uniformly to prepare a binder solution with a solids content of 7%. Next, the positive electrode active material manganese dioxide and the conductive agent were dissolved in the binder solution, and the mixture was mixed uniformly to prepare a positive electrode slurry. The conductive agent was prepared by mixing carbon nanotubes and graphite in a mass ratio of 1:1. S3. The mixture and the cathode slurry were uniformly mixed, and then lithium salt LiTFSI was added. After uniform stirring, the mixture was applied to both sides of a carbon-coated aluminum foil, which was used as a cathode current collector, and dried at a temperature of 90±5°C for 24±2 hours to form a 100μm-thick cathode active coating on each side. In S1, S2, and S3, the mass ratio was 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°C and humidity of 65±5%, the polymer solid electrolyte PEO, lithium salt LiTFSI, plasticizer acetonitrile, and solvent NMP were dehydrated in advance until the moisture content of each component was ≦20 ppm. The polymer solid electrolyte PEO, lithium salt LiTFSI, and plasticizer acetonitrile were thoroughly mixed, and then the solvent NMP was added and mixed uniformly to prepare an electrolyte solution. Calculated by mass ratio, the polymer solid electrolyte:plasticizer:lithium salt=60:8:30. S5. The electrolyte solution was applied to the surface of the positive electrode active coating and dried at 90±5°C for 24±2 hours to form an electrolyte layer with a thickness of 15 μm, thereby producing a positive electrode sheet. S6. After cutting the positive electrode sheet, it was assembled with the lithium metal piece of the negative electrode sheet to produce a lithium primary battery, with the electrolyte layer tightly attached to the negative electrode sheet.

[0025] Example 2 A lithium primary battery was fabricated by the following steps. S1. Under conditions of a temperature of 25±5°C and a humidity of 65±5%, the polymer solid electrolyte PEO, the oxide solid electrolyte LATP, and the solvent NMP were dehydrated in advance until the moisture content of each component was ≦20 ppm, and then uniformly mixed to prepare a mixed solution with a solid content of 10%. S2. Under conditions of a temperature of 25±5°C and a humidity of 65±5%, the positive electrode active material manganese dioxide, the conductive agent, the binder PVDF, and the solvent NMP were each dehydrated until the moisture content of each component was ≦20 ppm, and the binder PVDF and the solvent NMP were mixed uniformly to prepare a binder solution with a solids content of 7-10%. Next, the positive electrode active material manganese dioxide and the conductive agent were dissolved in the binder solution, and the mixture was mixed uniformly to prepare a positive electrode slurry. The conductive agent was prepared by mixing carbon nanotubes and graphite in a mass ratio of 1:2. S3. The mixture and the positive electrode slurry were uniformly mixed, and then lithium salt LiTFSI was added. After uniform stirring, the mixture was applied to both sides of a carbon-coated aluminum foil, which was used as a positive electrode current collector, and dried at a temperature of 90±5°C 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 was 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°C and humidity of 65±5%, the polymer solid electrolyte PEO, lithium salt LiTFSI, plasticizer acetonitrile, and solvent NMP were dehydrated in advance until the moisture content of each component was ≦20 ppm. The polymer solid electrolyte PEO, lithium salt LiTFSI, and plasticizer acetonitrile were thoroughly mixed, and then the solvent NMP was added and mixed uniformly to prepare an electrolyte solution. Calculated by mass ratio, the polymer solid electrolyte:plasticizer:lithium salt=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°C for 24±2 hours to form an electrolyte layer with a thickness of 6 μm, thereby producing a positive electrode sheet. S6. After cutting the positive electrode sheet, it was assembled with the lithium metal piece of the negative electrode sheet to produce a lithium primary battery, with the electrolyte layer tightly attached to the negative electrode sheet.

[0026] Example 3 A lithium primary battery was fabricated by the following steps. S1. Under conditions of a temperature of 25±5°C and a humidity of 65±5%, the polymer solid electrolyte PEO, the oxide solid electrolyte LATP, and the solvent NMP were dehydrated in advance until the moisture content of each component was ≦20 ppm, and then uniformly mixed to prepare a mixed solution with a solid content of 30%. S2. Under conditions of a temperature of 25±5°C and a humidity of 65±5%, the positive electrode active material manganese dioxide, the conductive agent, the binder PVDF, and the solvent NMP were each dehydrated until the moisture content of each component was ≦20 ppm, and the binder PVDF and the solvent NMP were mixed uniformly to prepare a binder solution with a solids content of 7-10%. Next, the positive electrode active material manganese dioxide and the conductive agent were dissolved in the binder solution, and the mixture was mixed uniformly to prepare a positive electrode slurry. The conductive agent was prepared by mixing carbon nanotubes and graphite in a mass ratio of 3:1. S3. The mixture and the positive electrode slurry were uniformly mixed, and then lithium salt LiTFSI was added. After uniform stirring, the mixture was applied to both sides of a carbon-coated aluminum foil, which was used as a positive electrode current collector, and dried at a temperature of 90±5°C 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 was 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°C and humidity of 65±5%, the polymer solid electrolyte PEO, lithium salt LiTFSI, plasticizer acetonitrile, and solvent NMP were dehydrated in advance until the moisture content of each component was ≦20 ppm. The polymer solid electrolyte PEO, lithium salt LiTFSI, and plasticizer acetonitrile were thoroughly mixed, and then the solvent NMP was added and mixed uniformly to prepare an electrolyte solution. Calculated by mass ratio, the polymer solid electrolyte:plasticizer:lithium salt=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°C for 24±2 hours to form an electrolyte layer with a thickness of 30 μm, thereby producing a positive electrode sheet. S6. After cutting the positive electrode sheet, it was assembled with the lithium metal piece of the negative electrode sheet to produce a lithium primary battery, with the electrolyte layer tightly attached to the negative electrode sheet.

[0027] Example 4 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in steps S1 and S4 of the lithium primary battery manufacturing process, the polymer solid electrolyte PEO is replaced with an equal amount of polymer solid electrolyte PPC. Except for the above differences, the materials, composition ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0028] Example 5 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in steps S1 and S4 of the lithium primary battery manufacturing process, the polymer solid electrolyte PEO is replaced with an equal amount of polymer solid electrolyte PAN. Except for the above differences, the materials, composition ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0029] Example 6 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in steps S1 and S4 of the lithium primary battery fabrication, the polymer solid electrolyte PEO is replaced with an equal amount of polymer solid electrolyte PDMS. Except for the above differences, the materials, compounding ratios, and fabrication procedures used in this example are strictly consistent with those in Example 1.

[0030] Example 7 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in step S4 of the lithium primary battery production, the polymer solid electrolyte PEO is replaced with an equal amount of polymer solid electrolyte PVDF. Except for the above difference, the materials, composition ratios, and production procedures used in this example are strictly consistent with those in Example 1.

[0031] Example 8 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in steps S1 and S4 of the lithium primary battery manufacturing process, the polymer solid electrolyte PEO is replaced with an equal amount of polymer solid electrolyte PMMA. Except for the above differences, the materials, compounding ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0032] Example 9 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in steps S1 and S4 of the lithium primary battery manufacturing process, the oxide solid electrolyte LATP is replaced with an equal amount of the oxide solid electrolyte LAGP. Except for the above differences, the materials, composition ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0033] Example 10 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in step S1 of the lithium primary battery production, the oxide solid electrolyte LATP is replaced with an equal amount of the oxide solid electrolyte LLTO. Except for the above difference, the materials, composition ratios, and production procedures used in this example are strictly consistent with those in Example 1.

[0034] Example 11 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in step S1 of the lithium primary battery production, the oxide solid electrolyte LATP is replaced with an equal amount of the oxide solid electrolyte LLZO. Except for the above difference, the materials, composition ratios, and production procedures used in this example are strictly consistent with those in Example 1.

[0035] Example 12 This example provides a lithium primary battery. Compared with Example 1, the structural differences are: (1) in step S3 of the lithium primary battery manufacturing process, the thickness of the positive electrode active coating is 40 μm; and (2) in step S5 of the lithium primary battery manufacturing process, the thickness of the electrolyte layer is 3 μm. Except for the above differences, the materials, compounding ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0036] Example 13 This example provides a lithium primary battery. Compared with Example 1, the structural differences are: (1) in step S3 of the lithium primary battery manufacturing process, the thickness of the positive electrode active coating is 180 μm; and (2) in step S5 of the lithium primary battery manufacturing process, the thickness of the electrolyte layer is 40 μm. Except for the above differences, the materials, compounding ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0037] Example 14 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in step S3 of the lithium primary battery manufacturing process, the positive electrode current collector is made of non-carbon-coated aluminum foil instead of carbon-coated aluminum foil. Except for this difference, the materials, composition ratios, and manufacturing procedures used in this example are strictly consistent with those in Example 1.

[0038] Example 15 This example provides a lithium primary battery. Compared with Example 1, the structural difference is that in step S4 of the lithium primary battery manufacturing process, the plasticizer is replaced with an equal amount of lithium salt. Except for this difference, the materials, compounding ratios, and manufacturing procedures used in this example are strictly consistent with 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 the 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 the 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 the 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 This test example took the primary lithium batteries manufactured according to Examples 1 to 16 and Comparative Examples 1 to 3 as the test objects and conducted relevant performance tests.

[0044] 2. Exam Content Battery self-discharge is an important parameter that characterizes the performance of lithium primary batteries. In this test example, the self-discharge of lithium primary batteries was tested mainly by the static measurement method. The lithium primary batteries were left static for a long period of time under specified environmental conditions (temperature 85°C, humidity 85%), and the change in open circuit voltage of the lithium primary batteries before and after leaving them static was measured to evaluate the degree of self-discharge of the batteries.

[0045] The annual self-discharge rate of the lithium primary battery was calculated using the following formula: The open circuit voltage of the lithium primary battery was measured when it was in a fully charged state before being left standing and recorded as V0, and the open circuit voltage of the lithium primary battery was measured after being left standing for 30 days under conditions of a temperature of 85°C and humidity of 85% and recorded as V1. The self-discharge rate of the lithium primary battery left standing for 30 days was η = [(V0 - V1) / V0] × 100%, and the annual self-discharge rate was obtained by estimating or converting based on the self-discharge rate of the lithium primary battery left standing for 30 days.

[0046] 3. Experimental Results

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

[0048] The relevant performance test results of the lithium primary batteries provided by Examples 1 to 16 and Comparative Examples 1 to 3 are shown in Table 1.

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

[0050] Compared with 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. 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 that of Example 1.

[0051] Compared with 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 batteries 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 batteries provided in Examples 9, 10, and 11 were LAGP, LLTO, and LLZO, respectively. Test results showed that 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 that of Example 1.

[0052] Compared with Example 1, the positive electrode active coating thickness of the positive electrode sheet of the lithium primary battery provided by Example 12 was <50 μm, and the electrolyte layer thickness was <6 μm, while the positive electrode active coating thickness of the positive electrode sheet of the lithium primary battery provided by Example 13 was >150 μm, and the electrolyte layer thickness was >30 μm. Test results showed that the annual self-discharge rates of the lithium primary batteries provided by Examples 12 and 13 were both higher than those of Example 1.

[0053] Compared with Example 1, the positive electrode current collector used in the positive electrode sheet of the lithium primary battery provided in Example 14 was an aluminum foil without a carbon coating, and the positive electrode active material used in the positive electrode sheet of the lithium primary battery provided in Example 16 was 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 disposed in that order on at least one surface of the positive electrode current collector, and an electrolyte layer, wherein the positive electrode active coating comprises a positive electrode active material, a polymer solid electrolyte, an oxide solid electrolyte, and a lithium salt, and the electrolyte layer comprises a polymer solid electrolyte and a lithium salt; the polymer solid electrolyte contains 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 (P.O. 4 ) 3 , Li 1.4 Al 0.4 Ti 1.6 (P.O. 4 ) 3 , Li 0.33 La 0.557 TiO 3 , Li 7 La 3 Zr 2 O 12 A lithium primary battery comprising at least one of the following:

2. The thickness of the positive electrode active coating is 50 to 150 μm; and / or 2. 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 (P.O. 4 ) 3 2. The lithium primary battery according to claim 1, wherein

4. The positive electrode active material is manganese dioxide, CF x 2. The lithium primary battery according to claim 1, comprising at least one of (0.5<x≦1).

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

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

7. 2. 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; 2. The lithium primary battery according to claim 1, wherein in the electrolyte layer, the mass ratio of the polymer solid electrolyte: the plasticizer: the lithium salt is 40 to 80: 5 to 10: 20 to 60.

9. A method for manufacturing a lithium primary battery, comprising: Step S1: preparing a mixed solution by using a polymer solid electrolyte and an oxide solid electrolyte and a solvent; Step S2: preparing a positive electrode slurry by using the positive electrode active material, a conductive agent, a binder, and a solvent; Step S3: uniformly mixing the mixed solution, the positive electrode slurry, and the lithium salt, and applying the mixture to at least one surface of a positive electrode current collector to form a positive electrode active coating; Step S4: preparing an electrolyte solution using a polymer solid electrolyte, a lithium salt, a plasticizer, and a solvent; Step S5: applying the electrolyte solution to the surface of the positive electrode active coating to form an electrolyte layer to manufacture a positive electrode sheet; and step S6 of assembling the positive electrode sheet and the negative electrode sheet to manufacture the lithium primary battery. the polymer solid electrolyte includes 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 (P.O. 4 ) 3 , Li 1.4 Al 0.4 Ti 1.6 (P.O. 4 ) 3 , Li 0.33 La 0.557 TiO 3 , Li 7 La 3 Zr 2 O 12 A method for producing a lithium primary battery comprising at least one of the following:

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

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