Positive electrode-side electrolyte separator, negative electrode-side electrolyte separator, lithium metal battery, and electric device

Abstract

The application discloses a positive electrode side electrolyte diaphragm, a negative electrode side electrolyte diaphragm, a lithium metal battery and an electric device, relates to the technical field of batteries, and the positive electrode side electrolyte diaphragm is applied to a lithium metal battery, a material of the positive electrode side electrolyte diaphragm comprises a first organic polymer, a first lithium salt, a first inorganic nano solid-state electrolyte and first inorganic oxide particles, wherein: the first organic polymer comprises an organic polymer with an antioxidation performance. By introducing the organic polymer with the antioxidation performance, the first lithium salt and the first inorganic oxide particles as the positive electrode side electrolyte diaphragm, the flexible characteristics of the organic solid-state electrolyte are utilized to reduce contact internal resistance, the risk of internal side reactions can be reduced, the rapid conduction of lithium ions is ensured, the formation of lithium dendrites is inhibited, and the safety and energy density of the battery are improved.

Description

TECHNICAL FIELD

[0001] The present application relates to the technical field of batteries, in particular to a positive electrode side electrolyte separator, a negative electrode side electrolyte separator, a lithium metal battery and an electric device. BACKGROUND

[0002] The energy density of the organic electrolyte system currently used by power batteries has approached the upper limit of the existing system. As the most likely next-generation power battery, solid-state batteries still face many problems. The problems faced by solid-state batteries mainly focus on the ion transport mechanism of solid-state electrolyte, the lithium dendrite growth mechanism of lithium metal negative electrode and the failure mechanism of multi-field coupling system, etc. These problems are directly related to the electrochemical performance, charging and discharging speed, capacity attenuation and safety of solid-state batteries. The main difference between solid-state batteries and liquid batteries is the state of the battery. Solid-state batteries mainly use solid-state electrolytes, including organic solid-state electrolytes, inorganic solid-state electrolytes and organic-inorganic composite electrolytes. Among them, the organic solid-state electrolyte has good flexibility and mechanical strength, and has different degrees of improvement for the interface wetting and lithium dendrite improvement, but compared with the liquid electrolyte, the ionic conductivity is low, which is mainly due to the strong interaction between ions in the organic solid-state electrolyte, the high ion migration energy barrier, and the certain crystallinity of the polymer, which hinders the transmission of lithium ions. The inorganic solid-state electrolyte has good electrochemical performance and mechanical strength, and can effectively inhibit the formation of lithium dendrites. However, the "solid-solid" interface contact problem between the inorganic solid-state electrolyte and the electrode may lead to shortening of the cycle life and performance decay of the battery, but its manufacturing difficulty is greater, the cost is higher, and the instability at high potential limits its application in high-voltage positive electrode materials. SUMMARY

[0003] The present application provides a positive electrode side electrolyte separator, a negative electrode side electrolyte separator, a lithium metal battery and an electric device to improve the shortcomings of solid-state electrolyte.

[0004] In a first aspect, the present application provides a positive electrode side electrolyte separator applied to a lithium metal battery, and the material thereof comprises a first organic polymer, a first lithium salt, a first inorganic nano solid-state electrolyte and a first inorganic oxide particle, wherein:

[0005] The first organic polymer comprises an organic polymer with antioxidant properties.

[0006] The application uses the flexible characteristics of the organic solid-state electrolyte to reduce the contact internal resistance, can reduce the risk of internal side reaction, ensure the rapid conduction of lithium ions, and inhibit the formation of lithium dendrites, thereby improving the safety and energy density of the battery. The organic polymer with antioxidant properties can exist stably during the charging and discharging reaction of the battery. Such organic polymers have strong antioxidant properties and are not easy to lose electrons. In the electrochemical reaction in the battery, they will not lose electrons before the positive electrode to cause side reactions, i.e., have a lower highest occupied molecular orbital (HOMO). At the same time, such organic polymers have good flexibility, which can reduce the contact internal resistance, and have a lower cost. The first lithium salt can form an organic polymer electrolyte with the organic polymer, providing conditions for lithium ion migration. The introduction of lithium salt ensures the ion conduction of the positive electrode side and provides a basis for the electrochemical reaction of the battery. The first inorganic oxide particles can reduce the crystallinity of the organic polymer. In general, the organic polymer with antioxidant properties has a certain crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction area and further improving the electrical performance. The first inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure the rapid conduction of lithium ions, and reduce the electrochemical polarization effect. Moreover, due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side can be effectively improved, the thermal shrinkage of the electrolyte caused by the heat generated by the electrochemical reaction can be eliminated, not only the lithium ion transmission efficiency is improved, but also the thermal runaway and mechanical damage in the battery are improved to different degrees.

[0007] In some embodiments, the first organic polymer includes at least one of polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polycaprolactone (PCL), and polyimide (PI). The above-mentioned first organic polymer can exist stably when the battery is subjected to a heavy discharging reaction, and the above-mentioned polymer has a wider electrochemical window (electrochemical window ≥ 4.5 V), and the voltage range exceeds the working voltage of a general battery and has strong antioxidant ability. Therefore, the first type of organic polymer is selected considering the electrochemical window range of the material, and the wider the range, the better the antioxidant ability.

[0008] In some embodiments, the first lithium salt comprises at least one of lithium hexafluorophosphate (LiPF6), lithium bisfluorosulfonylimide (Li(SO2F)2N), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(trifluorosulfonyl)imide (Li(CF3SO2)2N), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium difluorophosphate (LiPO2F2), and lithium difluorobis(oxalato)phosphate (LiDFPBOP). The first lithium salt can act as a lithium source in the organic-inorganic composite electrolyte. The first lithium salt has a stable structure and can exist stably in the battery system without causing side reactions. In addition, most of the lithium salts have a large anion structure, which can reduce the interaction of ionic bonds, promote the dissociation of lithium salt, and thus obtain a higher lithium ion transference number.

[0009] The first inorganic oxide particle comprises at least one of aluminum oxide (Al2O3), silicon oxide (SiO2), manganese dioxide (MnO2), zirconium oxide (ZrO2), titanium oxide (TiO2), boehmite, and calcium oxide (CaO). The first inorganic oxide particle can reduce the crystallinity of the organic polymer, and has good thermal stability and chemical stability, which can not only improve the thermal stability of the organic-inorganic composite electrolyte, but also effectively improve the mechanical strength of the electrolyte material.

[0010] The first inorganic nano solid-state electrolyte comprises at least one of an oxide electrolyte, a sulfide electrolyte, and a halide electrolyte. The first inorganic nano solid-state electrolyte can provide a transmission channel for lithium ion transmission, improve the ion transmission efficiency of the electrolyte system, and has stable performance and abundant supply, which can ensure the continuity of large-scale production and control the cost. The oxide electrolyte includes, but is not limited to, lithium aluminum titanium phosphate (LATP), lithium lanthanum zirconium oxide (LLZO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), and lithium aluminum germanium phosphate (LAGP). The sulfide electrolyte includes, but is not limited to, lithium germanium phosphorus sulfide (LGPS) and lithium phosphorus sulfide chloride (LPSCl). The halide electrolyte includes, but is not limited to, bromide (Li3YBr6) and chloride (Li3InCl5).

[0011] In some embodiments, the mass ratio of the first organic polymer, the first lithium salt, the first inorganic nano solid-state electrolyte, and the first inorganic oxide particle is (3-8): 1: (0.002-1): (0.002-1). The mass ratio of the first organic polymer, the first lithium salt, the first inorganic nano solid-state electrolyte, and the first inorganic oxide particle in this range can obtain good electrical properties while having good thermal stability and mechanical properties.

[0012] In some embodiments, the thickness of the cathode-side electrolyte separator is 5 μm to 80 μm. Within this range, the thickness of the cathode-side electrolyte separator can ensure good mechanical strength without causing a sharp increase in the interfacial resistance.

[0013] In a second aspect, the present application provides a negative electrode-side electrolyte separator applied to a lithium metal battery, the material of which comprises a second organic polymer, a second lithium salt, a second inorganic nano solid-state electrolyte, and a second inorganic oxide particle, wherein:

[0014] The second organic polymer comprises an organic polymer with anti-reduction performance.

[0015] By having the second organic polymer with anti-reduction performance, the second lithium salt and the second inorganic oxide particles as the negative electrode side electrolyte separator, a stable SEI interface can be formed on the surface of the lithium metal negative electrode to improve the stability of the electrolyte to lithium metal. The second organic polymer with anti-reduction performance can exist stably in electrochemical reaction, and the second organic polymer has a high lowest unoccupied molecular orbital (LUMO). Due to this characteristic, it is not easy to obtain electrons in electrochemical reaction, so the second organic polymer will not preferentially obtain electrons at the negative electrode side, and no side reaction will occur to affect the normal charge and discharge reaction of the battery. At the same time, the second lithium salt is added to form an organic polymer electrolyte and complete the construction of the lithium ion transfer channel. However, due to the existence of a large number of crystalline regions in the organic polymer, the second inorganic nano solid electrolyte is added to improve the proportion of amorphous regions in the polymer and increase the effective lithium ion transport area concentration. Moreover, the introduction of the inorganic nano solid electrolyte can increase the lithium ion transport channel and increase the lithium ion migration path, further improving the electrical performance. For the electrolyte material on the negative electrode side, not only excellent electrical performance is required, but also high mechanical strength is required to inhibit the formation of lithium dendrites. Therefore, the second inorganic oxide particles are added to improve the mechanical properties of the organic-inorganic composite electrolyte on the negative electrode side. Moreover, the organic-inorganic electrolyte itself has good flexibility, which can better contact with the electrode material, especially the lithium metal negative electrode, which can effectively reduce the contact resistance and improve the cycle performance and fast charging performance of the solid-state lithium metal battery. The second lithium salt can form an organic polymer electrolyte with the organic polymer to provide conditions for lithium ion migration. The introduction of lithium salt ensures the ion conduction on the positive electrode side and provides a basis for the electrochemical reaction of the battery. The first inorganic oxide particles can reduce the crystallinity of the organic polymer. Generally, the organic polymer with oxidation resistance has a certain crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction region and further improving the electrical performance. The first inorganic nano solid electrolyte can provide more channels for lithium ion migration, ensure fast conduction of lithium ions, and reduce electrochemical polarization effect. Moreover, due to the good mechanical properties and thermal stability of the inorganic nano solid electrolyte, the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side can be effectively improved, the thermal contraction of the electrolyte caused by the heat generated by the electrochemical reaction can be effectively eliminated, the lithium ion transport efficiency is improved, and the thermal runaway and mechanical damage in the battery are improved to different degrees. The second inorganic oxide particles can reduce the crystallinity of the organic polymer. Generally, the organic polymer with oxidation resistance has a certain crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction region and further improving the electrical performance.The second inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure fast conduction of lithium ions, reduce electrochemical polarization effect, and effectively improve the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, eliminate thermal shrinkage of the electrolyte caused by electrochemical reaction heat, not only improve the lithium ion transmission efficiency but also control the thermal runaway of the battery, and inhibit the formation of lithium dendrites.

[0016] In some embodiments, the second organic polymer includes at least one of polyethylene glycol (PEG), polyethylene oxide (PEO), polypropylene carbonate (PPC), polymethyl methacrylate (PMMA), polyethylene glycol dimethacrylate (PEGDMA), polyvinyl carbonate (PVC), polypropylene oxide (PPO), and acrylonitrile (SN). The above-mentioned second organic polymer can exist stably when the battery is subjected to a re-discharge reaction, and the above-mentioned polymer has a higher lowest unoccupied molecular orbital (LUMO), does not undergo redox reaction after contacting with a lithium metal negative electrode, and does not preferentially obtain electrons from the lithium metal negative electrode in an electrochemical reaction. Such materials have good resistance to reduction and are not easy to obtain electrons.

[0017] In some embodiments, the second lithium salt includes at least one of lithium hexafluorophosphate (LiPF6), lithium bisfluorosulfonylimide (Li(SO2F)2N), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(trifluorosulfonylimide) (Li(CF3SO2)2N), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium difluorophosphate (LiPO2F2), and lithium difluorobis(oxalato)phosphate (LiDFPBOP). The above-mentioned second lithium salt can act as a lithium source in the organic-inorganic composite electrolyte on the negative electrode side, and such structure lithium salt has a stable structure and can exist stably in the battery system without causing side reactions. At the same time, most of the above-mentioned lithium salts have a large anion structure, which can reduce the interaction of ionic bonds and increase the concentration of free lithium ions in the system; and / or,

[0018] The second inorganic oxide particles include at least one of aluminum oxide (Al2O3), silicon oxide (SiO2), manganese dioxide (MnO2), zirconium oxide (ZrO2), titanium oxide (TiO2), boehmite and calcium oxide (CaO). The above-mentioned second inorganic oxide particles can reduce the crystallinity of the organic polymer on the negative electrode side, while having good thermal stability and chemical stability, not only can improve the thermal stability of the organic-inorganic composite electrolyte on the negative electrode side to improve the heat shrinkage resistance, but also can correspondingly improve the mechanical strength of the negative organic-inorganic composite solid electrolyte, further inhibit the growth of lithium dendrites, and the above-mentioned inorganic oxide nanoparticles are low in price, can realize cost control and / or

[0019] The second inorganic nano solid electrolyte includes at least one of oxide electrolyte, sulfide electrolyte and halide electrolyte. The above-mentioned second inorganic nano solid electrolyte can provide a transmission channel for the transmission of lithium ions, improve the ion transmission efficiency of the electrolyte system, and the above-mentioned solid electrolyte has stable performance and abundant supply, which can ensure the continuity of large-scale production and control the cost. The oxide electrolyte includes but is not limited to lithium aluminum titanium phosphate (LATP), lithium lanthanum zirconium oxide (LLZO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), lithium aluminum germanium phosphate (LAGP). The sulfide electrolyte includes but is not limited to lithium germanium phosphorus sulfide (LGPS), lithium phosphorus sulfide chloride (LPSCl). The halide electrolyte includes but is not limited to bromide (Li3YBr6) and chloride (Li3InCl5).

[0020] In some embodiments, the mass ratio of the second organic polymer, the second lithium salt, the second inorganic nano solid electrolyte and the second inorganic oxide particles is (3-8):1:(0.002-1):(0.002-1). The mass ratio of the second organic polymer, the second lithium salt, the second inorganic nano solid electrolyte and the second inorganic oxide particles in this range can obtain good electrical performance while having good thermal stability and mechanical properties.

[0021] In some embodiments, the thickness of the negative electrode side electrolyte separator is 10-40 μm. The thickness of the negative electrode side electrolyte separator in this range can ensure good mechanical strength and not cause a sharp increase in the interfacial resistance.

[0022] In a third aspect, the application provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein:

[0023] The first aspect of the positive electrode and the solid electrolyte layer is provided with a positive electrode side electrolyte separator;

[0024] The second aspect of the negative electrode and the solid electrolyte layer is provided with a negative electrode side electrolyte separator.

[0025] Due to the asymmetric organic-inorganic composite solid electrolyte separator of the positive electrode side electrolyte separator and the negative electrode side electrolyte separator, the electrolyte not only has good electrical performance, but also has good thermal stability and mechanical performance, which can not only reduce the risk of thermal runaway, but also can inhibit the generation of lithium dendrites. The asymmetric structure design effectively eliminates the occurrence of internal side reactions, and will not cause safety hazards due to decomposition gas caused by high temperature and high voltage environment like liquid electrolyte. The positive electrode side organic-inorganic composite electrolyte has strong oxidation resistance and will not lose electrons preferentially at the positive electrode. The negative electrode side organic-inorganic composite electrolyte has strong reduction resistance and will not gain electrons preferentially at the negative electrode. It is this asymmetric design that not only ensures the normal charge-discharge reaction of the battery, but also effectively inhibits the occurrence of internal side reactions and the generation of lithium dendrites, improves the electrochemical stability, interface compatibility and thermal stability of the solid-state electrolyte, not only reduces the "solid-solid" interface impedance, but also improves the lithium ion conduction efficiency. At the same time, due to the rigidity of the inorganic solid-state electrolyte, it can effectively improve the inhibition of lithium dendrites and improve the safety of the battery.

[0026] The main principle utilizes the first organic polymer with a lower highest occupied molecular orbital (HOMO), which is stable in structure and not easy to be oxidized, especially in the battery system, and after contacting with the positive electrode, it is not easy to lose electrons in the electrochemical reaction, thereby causing irreversible side reactions, so the first organic polymer has higher electrical stability and a wider electrochemical window. At the same time, the first lithium salt is used as the electrolyte to form an organic polymer electrolyte with the first polymer, which can realize lithium ion conduction. However, the polymer generally has a high crystallinity at room temperature, and lithium ions generally migrate in the amorphous region, so the ionic conductivity of the organic polymer electrolyte is low. In order to further improve the conductivity of the electrolyte, inorganic nano solid-state electrolytes are introduced, which not only increase the transmission channel and efficiency of lithium ions, but also have good thermal stability and oxidation resistance. In addition, the inorganic oxide particles can further reduce the crystallinity of the organic polymer and improve the lithium ion transmission efficiency, thereby further improving the electrical performance and thermodynamic stability of the organic-inorganic composite solid-state electrolyte on the positive electrode side. Moreover, the added nano inorganic oxide can effectively improve the mechanical strength of the organic-inorganic electrolyte on the positive electrode side, reduce the generation probability of lithium dendrites, and thereby reduce the risk of short circuit in the battery, so that the electrical performance and safety are improved. Similarly, the organic-inorganic composite electrolyte is designed on the negative electrode side, and the second polymer is selected as the matrix material of the organic-inorganic electrolyte. The second organic polymer is different from the first organic polymer, and the second organic polymer has a higher lowest unoccupied molecular orbital (LUMO). Due to this property, the second organic polymer cannot obtain electrons preferentially on the negative electrode in the electrochemical reaction, and thus side reactions do not occur to affect the normal charge and discharge reaction of the battery. At the same time, the second lithium salt is added to form an organic polymer electrolyte to complete the construction of the lithium ion transmission channel. However, due to the existence of a large number of crystalline regions in the organic polymer, the second inorganic nano solid-state electrolyte is added to increase the proportion of the amorphous region of the polymer and increase the effective lithium ion transmission area concentration. Moreover, the introduction of the inorganic nano solid-state electrolyte can increase the transmission channel of lithium ions and increase the migratable path of lithium ions, thereby further improving the electrical performance. For the electrolyte material on the negative electrode side, not only excellent electrical performance is required, but also high mechanical strength is required to inhibit the formation of lithium dendrites. Therefore, the second inorganic oxide particles are added to improve the mechanical performance of the organic-inorganic composite electrolyte on the negative electrode side. Moreover, the organic-inorganic electrolyte itself has good flexibility, which can be in good contact with the electrode material, especially the lithium metal negative electrode, thereby effectively reducing the contact resistance and improving the cycle performance and fast charging performance of the solid-state lithium metal battery.

[0027] In some embodiments, the thickness ratio of the positive electrode side electrolyte separator, the solid-state electrolyte layer, and the negative electrode side electrolyte separator is (1-2): 1: (0.5-2). When the thickness ratio of the positive electrode side electrolyte separator, the solid-state electrolyte layer, and the negative electrode side electrolyte separator is within this range, good electrical performance can be obtained while good thermal stability and mechanical performance are also provided.

[0028] The thickness of the solid-state electrolyte layer is 5-50 μm. When the thickness of the solid-state electrolyte layer is within this range, good mechanical strength can be ensured without causing a sharp increase in the interfacial resistance.

[0029] In some embodiments, the material of the solid-state electrolyte layer comprises a third inorganic nanometer solid-state electrolyte, which comprises at least one of an oxide electrolyte, a sulfide electrolyte, and a halide electrolyte. The third inorganic nanometer solid-state electrolyte can provide a transmission channel for the transmission of lithium ions, improve the ion transmission efficiency of the electrolyte system, and the solid-state electrolyte has stable performance and abundant supply, which can ensure the continuity of large-scale production and control the cost. The oxide electrolyte includes, but is not limited to, lithium titanium aluminum phosphate (LATP), lithium lanthanum zirconium oxide (LLZO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), and lithium aluminum germanium phosphate (LAGP). The sulfide electrolyte includes, but is not limited to, lithium germanium phosphorus sulfide (LGPS) and lithium phosphorus sulfide chloride (LPSCl). The halide electrolyte includes, but is not limited to, bromide (Li3YBr6) and chloride (Li3InCl5).

[0030] In some embodiments, the Dv 50 of the third inorganic nanometer solid-state electrolyte is 100-900 nm. The Dv 50 of the inorganic nanometer solid-state electrolyte is 100-900 nm. Within this range, the transmission efficiency of lithium ions can be effectively improved, and the mechanical performance of the nanometer electrolyte is more significantly improved. The Dv 50 is the median particle size of the inorganic nanometer solid-state electrolyte, which refers to the particle size value corresponding to a cumulative percentage of 50%, and is usually used to represent the average particle size of the powder. The Dv 50 can be measured by a laser particle size analyzer method.

[0031] In some embodiments, the working temperature of the lithium metal battery is -40-120°C. When the working temperature of the lithium metal battery is within this range, all temperature requirements of the commercial scenarios of lithium ion batteries (the current working temperature of commercial liquid lithium ion batteries is -25-65°C.

[0032] In a fourth aspect, the present application provides a power utilization device comprising the lithium metal battery of the third aspect. BRIEF DESCRIPTION OF DRAWINGS

[0033] In order to more clearly illustrate the technical solutions in the embodiments of the present application, the drawings needed to be used in the embodiments description will be briefly introduced. Obviously, the drawings in the following description are only some embodiments of the present application, and other drawings can be obtained by those skilled in the art without any creative effort based on these drawings.

[0034] Figure 1 The structure schematic diagram of the lithium metal battery of an embodiment of the present application.

[0035] Figure 2 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 15 of the present application.

[0036] Figure 3 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 16 of the present application.

[0037] Figure 4 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 17 of the present application.

[0038] Figure 5 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 18 of the present application.

[0039] Figure 6 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 19 of the present application.

[0040] Figure 7 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 20 of the present application.

[0041] Figure 8 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 21 of the present application.

[0042] Figure 9 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 22 of the present application.

[0043] Figure 10 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 23 of the present application.

[0044] Figure 11 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 24 of the present application.

[0045] Figure 12 The capacity retention rate and coulombic efficiency performance diagram of the lithium metal battery of embodiment 25 of the present application.

[0046] Figure 13Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 5 of the present application.

[0047] Figure 14 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 6 of the present application.

[0048] Figure 15 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 7 of the present application.

[0049] Figure 16 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 8 of the present application.

[0050] Figure 17 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 9 of the present application.

[0051] Figure 18 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 10 of the present application.

[0052] Figure 19 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 11 of the present application.

[0053] Figure 20 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 12 of the present application.

[0054] Figure 21 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 13 of the present application.

[0055] Figure 22 Capacity retention and coulombic efficiency performance plot for lithium metal battery of Comparative Example 14 of the present application. DETAILED DESCRIPTION

[0056] In order to enable persons skilled in the art to better understand the present application, the technical solutions in the embodiments of the present application are described clearly and completely. Obviously, the described embodiments are only some of the embodiments of the present application, not all the embodiments. Based on the embodiments in the present application, all other embodiments obtained by persons skilled in the art without creative labor fall within the scope of protection of the present application.

[0057] The energy density of the current organic electrolyte system used in power batteries has approached the upper limit of the existing system. Solid-state batteries, as the most likely next-generation power batteries, still face many problems. The problems faced by solid-state batteries mainly focus on the ion transport mechanism of solid-state electrolyte, the lithium dendrite growth mechanism of lithium metal anode, and the failure mechanism of multi-field coupling system, etc. These problems are directly related to the electrochemical performance, charging and discharging speed, capacity attenuation and safety of solid-state batteries. The main difference between solid-state batteries and liquid batteries is the state of the battery. Solid-state batteries mainly use solid-state electrolytes, including organic solid-state electrolytes, inorganic solid-state electrolytes, and organic-inorganic composite electrolytes. Among them, the organic solid-state electrolyte has good flexibility and mechanical strength, and can improve the interface wetting and lithium dendrite to some extent, but compared with liquid electrolyte, the ionic conductivity is low, which is mainly due to the strong interaction between ions in the organic solid-state electrolyte, high ion migration energy barrier, and the polymer has certain crystallinity, which hinders the transmission of lithium ions. Inorganic solid-state electrolyte has good electrochemical performance and mechanical strength, which can effectively inhibit the formation of lithium dendrites. However, the "solid-solid" interface contact problem between inorganic solid-state electrolyte and electrode may lead to shortening of battery cycle life and performance decay, but its manufacturing difficulty is greater, the cost is higher, and the instability at high potential limits its application in high-voltage cathode materials.

[0058] Therefore, the application provides a positive electrode side electrolyte separator, a negative electrode side electrolyte separator, a lithium metal battery and an electric device to improve the limitations of solid-state electrolyte.

[0059] In a first aspect, the application provides a positive electrode side electrolyte separator applied to a lithium metal battery, and the material thereof comprises a first organic polymer, a first lithium salt, a first inorganic nano solid-state electrolyte and a first inorganic oxide particle, wherein:

[0060] The first organic polymer comprises an organic polymer with antioxidant properties.

[0061] The application uses the flexible characteristics of the organic solid-state electrolyte to reduce the contact internal resistance, can reduce the risk of internal side reactions, ensure the rapid conduction of lithium ions, and inhibit the formation of lithium dendrites, thereby improving the safety and energy density of the battery. The organic polymer with antioxidant properties can exist stably during the charging and discharging reaction of the battery. Such organic polymers have strong antioxidant properties and are not easy to lose electrons. In the electrochemical reaction inside the battery, they will not lose electrons before the positive electrode to cause side reactions, i.e., have a lower highest occupied molecular orbital (HOMO). At the same time, such organic polymers have good flexibility, which can reduce the contact internal resistance, and have a lower cost. The first lithium salt can form an organic polymer electrolyte with the organic polymer, providing conditions for lithium ion migration. The introduction of lithium salt ensures the ion conduction of the positive electrode side and provides a basis for the electrochemical reaction of the battery. The first inorganic oxide particles can reduce the crystallinity of the organic polymer. In general, the organic polymer with antioxidant properties has a certain crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction area and further improving the electrical performance. The first inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure the rapid conduction of lithium ions, and reduce the electrochemical polarization effect. Moreover, due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side can be effectively improved, the thermal shrinkage of the electrolyte caused by the heat generated by the electrochemical reaction can be effectively eliminated, not only the lithium ion transmission efficiency is improved, but also the thermal runaway and mechanical damage inside the battery are improved to different degrees.

[0062] In combination with the first aspect, in some embodiments provided by the application, the first organic polymer includes at least one of polyvinylidene fluoride (PVDF), polyacrylonitrile (PAN), polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP), polycaprolactone (PCL), and polyimide (PI). The above-mentioned first organic polymer can exist stably when the battery is subjected to a heavy discharging reaction, and the above-mentioned polymer has a wider electrochemical window (electrochemical window ≥ 4.5 V), and the voltage range exceeds the working voltage of a general battery and has strong antioxidant ability. Therefore, the first type of organic polymer is selected considering the electrochemical window range of the material, and the wider the range, the better the antioxidant ability.

[0063] In some embodiments of the first aspect, the first lithium salt includes at least one of lithium hexafluorophosphate (LiPF6), lithium bisfluorosulfonylimide (Li(SO2F)2N), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(trifluorosulfonyl)imide (Li(CF3SO2)2N), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium difluorophosphate (LiPO2F2), and lithium difluorobis(oxalato)phosphate (LiDFPBOP). The first lithium salt can act as a lithium source in the organic-inorganic composite electrolyte. The first lithium salt has a stable structure and can exist stably in the battery system without causing side reactions. In addition, most of the lithium salts have a large anion structure, which can reduce the interaction of ionic bonds, promote the dissociation of lithium salt, and thus obtain a higher lithium ion transference number.

[0064] In some embodiments of the first aspect, the first inorganic oxide particle includes at least one of aluminum oxide (Al2O3), silicon oxide (SiO2), manganese dioxide (MnO2), zirconium oxide (ZrO2), titanium oxide (TiO2), boehmite, and calcium oxide (CaO). The first inorganic oxide particle can reduce the crystallinity of the organic polymer, and has good thermal stability and chemical stability, which can improve the thermal stability of the organic-inorganic composite electrolyte and effectively improve the mechanical strength of the electrolyte material.

[0065] In some embodiments of the first aspect, the first inorganic nano solid-state electrolyte includes at least one of an oxide electrolyte, a sulfide electrolyte, and a halide electrolyte. The first inorganic nano solid-state electrolyte can provide a transmission channel for lithium ion transmission, improve the ion transmission efficiency of the electrolyte system, and has stable performance and abundant supply, which can ensure the continuity of large-scale production and control the cost. The oxide electrolyte includes, but is not limited to, lithium aluminum titanium phosphate (LATP), lithium lanthanum zirconium oxide (LLZO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), and lithium aluminum germanium phosphate (LAGP). The sulfide electrolyte includes, but is not limited to, lithium germanium phosphorus sulfide (LGPS) and lithium phosphorus sulfide chloride (LPSCl). The halide electrolyte includes, but is not limited to, bromide (Li3YBr6) and chloride (Li3InCl5).

[0066] In some embodiments of the first aspect, the mass ratio of the first organic polymer, the first lithium salt, the first inorganic nano-solid-state electrolyte, and the first inorganic oxide particles is (3-8): 1: (0.002-1): (0.002-1). The mass ratio of the first organic polymer, the first lithium salt, the first inorganic nano-solid-state electrolyte, and the first inorganic oxide particles in this range can achieve good electrical properties while having good thermal stability and mechanical properties.

[0067] In some embodiments of the first aspect, the thickness of the positive electrode side electrolyte separator is 5-80 μm. The thickness of the positive electrode side electrolyte separator in this range can ensure good mechanical strength without causing a sharp increase in the interfacial resistance.

[0068] In the second aspect, the application provides a negative electrode side electrolyte separator for a lithium metal battery, which comprises a second organic polymer, a second lithium salt, a second inorganic nano-solid-state electrolyte, and a second inorganic oxide particle, wherein:

[0069] The second organic polymer comprises an organic polymer with anti-reduction properties.

[0070] By having the second organic polymer with anti-reduction performance, the second lithium salt and the second inorganic oxide particles as the negative electrode side electrolyte separator, a stable SEI interface can be formed on the surface of the lithium metal negative electrode to improve the stability of the electrolyte to lithium metal. The second organic polymer with anti-reduction performance can exist stably in electrochemical reaction, and the second organic polymer has a high lowest unoccupied molecular orbital (LUMO). Due to this characteristic, it is not easy to obtain electrons in electrochemical reaction, so the second organic polymer will not preferentially obtain electrons at the negative electrode side, and no side reaction will occur to affect the normal charge and discharge reaction of the battery. At the same time, the second lithium salt is added to form an organic polymer electrolyte and complete the construction of the lithium ion transfer channel. However, due to the existence of a large number of crystalline regions in the organic polymer, the second inorganic nano solid electrolyte is added to improve the proportion of amorphous regions in the polymer and increase the effective lithium ion transport area concentration. Moreover, the introduction of the inorganic nano solid electrolyte can increase the lithium ion transport channel and increase the lithium ion migration path, further improving the electrical performance. For the electrolyte material on the negative electrode side, not only excellent electrical performance is required, but also high mechanical strength is required to inhibit the formation of lithium dendrites. Therefore, the second inorganic oxide particles are added to improve the mechanical properties of the organic-inorganic composite electrolyte on the negative electrode side. Moreover, the organic-inorganic electrolyte itself has good flexibility, which can better contact with the electrode material, especially the lithium metal negative electrode, which can effectively reduce the contact resistance and improve the cycle performance and fast charging performance of the solid-state lithium metal battery. The second lithium salt can form an organic polymer electrolyte with the organic polymer to provide conditions for lithium ion migration. The introduction of lithium salt ensures the ion conduction on the positive electrode side and provides a basis for the electrochemical reaction of the battery. The first inorganic oxide particles can reduce the crystallinity of the organic polymer. Generally, the organic polymer with oxidation resistance has a certain crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction region and further improving the electrical performance. The first inorganic nano solid electrolyte can provide more channels for lithium ion migration, ensure fast conduction of lithium ions, and reduce electrochemical polarization effect. Moreover, due to the good mechanical properties and thermal stability of the inorganic nano solid electrolyte, the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side can be effectively improved, the thermal contraction of the electrolyte caused by the heat generated by the electrochemical reaction can be effectively eliminated, the lithium ion transport efficiency is improved, and the thermal runaway and mechanical damage in the battery are improved to different degrees. The second inorganic oxide particles can reduce the crystallinity of the organic polymer. Generally, the organic polymer with oxidation resistance has a certain crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction region and further improving the electrical performance.The second inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure fast conduction of lithium ions, reduce electrochemical polarization effect, and effectively improve the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, eliminate thermal shrinkage of the electrolyte caused by electrochemical reaction heat, not only improve the lithium ion transmission efficiency but also control the thermal runaway of the battery, and inhibit the formation of lithium dendrites.

[0071] In combination with the second aspect, in some embodiments provided in the present application, the second organic polymer includes at least one of polyethylene glycol (PEG), polyethylene oxide (PEO), polypropylene carbonate (PPC), polymethyl methacrylate (PMMA), polyethylene glycol dimethacrylate (PEGDMA), polyvinyl carbonate (PVC), polypropylene oxide (PPO), and acrylonitrile (SN). The above-mentioned second organic polymer can stably exist when the battery is subjected to a re-discharge reaction, and the above-mentioned polymer has a higher lowest unoccupied molecular orbital (LUMO), does not undergo redox reaction after contacting with a lithium metal negative electrode, and does not preferentially obtain electrons from the lithium metal negative electrode in an electrochemical reaction. Such materials have good resistance to reduction and are not easy to obtain electrons.

[0072] In combination with the second aspect, in some embodiments provided in the present application, the second lithium salt includes at least one of lithium hexafluorophosphate (LiPF6), lithium bisfluorosulfonylimide (Li(SO2F)2N), lithium perchlorate (LiClO4), lithium tetrafluoroborate (LiBF4), lithium bis(trifluorosulfonyl)imide (Li(CF3SO2)2N), lithium bis(oxalato)borate (LiBOB), lithium difluoro(oxalato)borate (LiDFOB), lithium difluorophosphate (LiPO2F2), and lithium difluorobis(oxalato)phosphate (LiDFPBOP). The above-mentioned second lithium salt can act as a lithium source in the organic-inorganic composite electrolyte on the negative electrode side, and such structure lithium salt has a stable structure and can stably exist in the battery system without causing side reactions. At the same time, most of the above-mentioned lithium salt has a large anion structure, which can reduce the interaction of ionic bonds and increase the concentration of free lithium ions in the system.

[0073] In some embodiments of the second aspect, the second inorganic oxide particles include at least one of aluminum oxide (Al2O3), silicon oxide (SiO2), manganese dioxide (MnO2), zirconium oxide (ZrO2), titanium oxide (TiO2), boehmite, and calcium oxide (CaO). The second inorganic oxide particles can reduce the crystallinity of the organic polymer on the negative electrode side, while having good thermal stability and chemical stability. The second inorganic oxide particles can not only improve the thermal stability of the organic-inorganic composite electrolyte on the negative electrode side to improve the heat shrinkage resistance, but also can correspondingly improve the mechanical strength of the negative electrode organic-inorganic composite solid electrolyte, further inhibit the growth of lithium dendrites, and the inorganic oxide nanoparticles are low in price and can realize large-scale cost control.

[0074] In some embodiments of the second aspect, the second inorganic nano solid electrolyte includes at least one of an oxide electrolyte, a sulfide electrolyte, and a halide electrolyte. The second inorganic nano solid electrolyte can provide a transmission channel for the transmission of lithium ions, improve the ion transmission efficiency of the electrolyte system, and has stable performance and abundant supply, which can ensure the continuity of large-scale production and control the cost. The oxide electrolyte includes, but is not limited to, lithium aluminum titanium phosphate (LATP), lithium lanthanum zirconium oxide (LLZO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), and lithium aluminum germanium phosphate (LAGP). The sulfide electrolyte includes, but is not limited to, lithium germanium phosphorus sulfide (LGPS) and lithium phosphorus sulfide chloride (LPSCl). The halide electrolyte includes, but is not limited to, bromide (Li3YBr6), chloride (Li10SnCl10), and iodide (Li3InI6). i3 InCl5).

[0075] In some embodiments of the second aspect, the mass ratio of the second organic polymer, the second lithium salt, the second inorganic nano solid electrolyte, and the second inorganic oxide particles is (3-8):1:(0.002-1):(0.002-1). The mass ratio of the second organic polymer, the second lithium salt, the second inorganic nano solid electrolyte, and the second inorganic oxide particles in this range can obtain good electrical properties while having good thermal stability and mechanical properties.

[0076] In some embodiments of the second aspect, the thickness of the negative electrode side electrolyte separator is 10-40 μm. The thickness of the negative electrode side electrolyte separator in this range can ensure good mechanical strength and not cause a sharp increase in the interfacial resistance.

[0077] In a third aspect, the present application provides a lithium metal battery, as shown in FIG. 2, which includes a positive electrode 1, a solid electrolyte layer 2, and a negative electrode 3, wherein: Figure 1

[0078] ​The positive electrode 1 and the solid-state electrolyte layer 2 are provided with the positive electrode side electrolyte separator 4 of the first aspect;

[0079] The negative electrode 3 and the solid-state electrolyte layer 2 are provided with the negative electrode side electrolyte separator 5 of the second aspect.

[0080] Due to the asymmetric organic-inorganic composite solid-state electrolyte separator of the positive electrode side electrolyte separator 4 and the negative electrode side electrolyte separator 5, the electrolyte not only has good electrical properties, but also has good thermal stability and mechanical properties, which can not only reduce the risk of thermal runaway but also inhibit the generation of lithium dendrites. This asymmetric structure design effectively eliminates the occurrence of internal side reactions, unlike liquid electrolytes which can cause safety hazards due to decomposition gas caused by high temperature and high voltage environment. The positive electrode side organic-inorganic composite electrolyte has strong oxidation resistance and will not lose electrons preferentially at the positive electrode. The negative electrode side organic-inorganic composite electrolyte has strong reduction resistance and will not gain electrons preferentially at the negative electrode. It is this asymmetric design that not only ensures the normal charge-discharge reaction of the battery, but also effectively inhibits the occurrence of internal side reactions and the generation of lithium dendrites, improving the electrochemical stability, interface compatibility and thermal stability of the solid-state electrolyte. Not only does it reduce the "solid-solid" interface impedance, but also improves the lithium ion conduction efficiency. At the same time, due to the rigidity of the inorganic solid-state electrolyte, it can effectively improve the inhibition of lithium dendrites and improve the safety of the battery.

[0081] The main principle of the present application is to use the first organic polymer with a lower highest occupied molecular orbital (HOMO), which is stable in structure and not easy to be oxidized, especially in the battery system, after contacting with the positive electrode 1, it is not easy to lose electrons in the electrochemical reaction, causing irreversible side reactions, so the first organic polymer has higher electrical stability and a wider electrochemical window; at the same time, the first lithium salt is used as the electrolyte to form an organic polymer electrolyte with the first polymer, which can realize lithium ion conduction, but due to the high crystallinity of the polymer at room temperature, lithium ions generally migrate in the amorphous region, so the ionic conductivity of the organic polymer electrolyte is low. In order to further improve the conductivity of the electrolyte, inorganic nano solid-state electrolyte is introduced, which not only increases the transmission channel and efficiency of lithium ions, but also has good thermal stability and oxidation resistance. In addition, the inorganic oxide particles can further reduce the crystallinity of the organic polymer and improve the lithium ion transfer efficiency, further improving the electrical performance and thermodynamic stability of the organic-inorganic composite solid-state electrolyte on the positive electrode side. The added nano inorganic oxide can effectively improve the mechanical strength of the organic-inorganic electrolyte on the positive electrode side, reduce the probability of lithium dendrite formation, and thus reduce the risk of short circuit in the battery, so that the electrical performance and safety are improved. Similarly, the organic-inorganic composite electrolyte is designed on the negative electrode 3 side, and the second polymer is selected as the matrix material of the organic-inorganic electrolyte. The second organic polymer is different from the first organic polymer, and the second organic polymer has a higher lowest unoccupied molecular orbital (LUMO). Due to this characteristic, the second organic polymer cannot obtain electrons preferentially on the negative electrode 3 side, and cannot cause side reactions to affect the normal charge and discharge reaction of the battery. At the same time, the second lithium salt is added to form an organic polymer electrolyte to complete the construction of the lithium ion transfer channel. However, due to the existence of a large number of crystalline regions in the organic polymer, the second inorganic nano solid-state electrolyte is added to increase the proportion of amorphous regions in the polymer and increase the effective lithium ion transmission area concentration. The introduction of inorganic nano solid-state electrolyte can increase the transmission channel of lithium ions and increase the migratable path of lithium ions, further improving the electrical performance. For the electrolyte material on the negative electrode side, not only excellent electrical performance is required, but also high mechanical strength is required to inhibit the formation of lithium dendrites, so the second inorganic oxide particles are added to improve the mechanical properties of the organic-inorganic composite electrolyte on the negative electrode side. Moreover, the organic-inorganic electrolyte itself has good flexibility, which can better contact with the electrode material, especially the lithium metal negative electrode, which can effectively reduce the contact resistance and improve the cycle performance and fast charging performance of the solid-state lithium metal battery.

[0082] In some embodiments of the third aspect, the thickness ratio of the positive electrode electrolyte separator 4, the solid-state electrolyte layer 2, and the negative electrode electrolyte separator 5 is (1-2):1:(0.5-2). When the thickness ratio of the positive electrode electrolyte separator 4, the solid-state electrolyte layer 2, and the negative electrode electrolyte separator 5 is within the range, good electrical performance, good thermal stability, and good mechanical performance can be achieved.

[0083] In some embodiments of the third aspect, the thickness of the solid-state electrolyte layer 2 is 5-50 microns. When the thickness of the solid-state electrolyte layer 2 is within the range, good mechanical strength can be ensured without causing a sharp increase in the interfacial resistance.

[0084] In some embodiments of the third aspect, the material of the solid-state electrolyte layer 2 includes a third inorganic nano solid-state electrolyte, which includes at least one of an oxide electrolyte, a sulfide electrolyte, and a halide electrolyte. The third inorganic nano solid-state electrolyte can provide a transmission channel for lithium ion transmission, improve the ion transmission efficiency of the electrolyte system, and has stable performance and abundant supply, which can ensure the continuity of large-scale production and control the cost. The oxide electrolyte includes, but is not limited to, lithium aluminum titanium phosphate (LATP), lithium lanthanum zirconium oxide (LLZO), tantalum-doped lithium lanthanum zirconium oxide (LLZTO), and lithium aluminum germanium phosphate (LAGP). The sulfide electrolyte includes, but is not limited to, lithium germanium phosphorus sulfide (LGPS) and lithium phosphorus sulfide chloride (LPSCl). The halide electrolyte includes, but is not limited to, bromide (Li3YBr6) and chloride (Li3InCl5).

[0085] In some embodiments of the third aspect, the Dv50 of the third inorganic nano solid-state electrolyte is 100-900 nm. 50 In some embodiments of the third aspect, the Dv50 of the third inorganic nano solid-state electrolyte is 100-900 nm. 50 Within the range, the transmission efficiency of lithium ions can be effectively improved, and the mechanical performance of the nano-level electrolyte is more significant for improving the mechanical performance of the electrolyte material. 50 Dv50 refers to the median particle size of the inorganic nano solid-state electrolyte, which refers to the particle size value corresponding to the cumulative percentage of 50%, and is usually used to represent the average particle size of the powder. Dv 50 The Dv50 can be measured by a laser particle size analyzer method.

[0086] In some embodiments of the third aspect, the working temperature of the lithium metal battery is -40-120°C. When the working temperature of the lithium metal battery is within the range, all temperature requirements of the commercial scenario of lithium ion batteries (the working temperature of the current commercial liquid lithium ion battery is -25-65°C.

[0087] In a fourth aspect, the present application provides a power consuming device comprising the lithium metal battery of the third aspect. The power consuming device includes, but is not limited to, a lithium metal battery, a sodium metal battery, a zinc metal battery, and the like alkali metal battery. The power consuming device has all the technical solutions of the lithium metal battery, and thus has all the beneficial effects of the lithium metal battery. The present application will not be repeated here.

[0088] The technical solutions provided by the present application will be described in detail below in conjunction with the embodiments.

[0089] Embodiment 1

[0090] In the positive electrode side electrolyte separator provided in Embodiment 1 of the present application, lithium bisfluorosulfonylimide (Li(SO2F)2N) and lithium perchlorate (LiClO4) are mixed at a mass ratio of 1:1 to obtain a first lithium salt. The first lithium salt and a polymer polyacrylonitrile (PAN) are mixed at a mass ratio of 1:4, and then put into a banbury mixer for melt mixing. After melting, silicon oxide (SiO2) is added (the mass ratio of SiO2 to the first lithium salt is 1:4), and the Dv 50 nanopowder LATP with a particle size of 200 nm (the mass ratio of the nanopowder LATP to the first lithium salt is 1:4). The first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte, and the first inorganic oxide particles are mixed and stirred for 4 h to obtain an electrolyte separator slurry on the positive electrode side. The electrolyte separator slurry on the positive electrode side is cast on the surface of the positive electrode, and hot pressing is performed to obtain the positive electrode side electrolyte separator.

[0091] Embodiment 2

[0092] In the positive electrode side electrolyte separator provided in Embodiment 2 of the present application, lithium bis(trifluorosulfonylimide) (Li(CF3SO2)2N) and polyvinylidene fluoride (PVDF) are mixed at a mass ratio of 1:6. After melt mixing, titanium oxide (TiO2) is added (the mass ratio of TiO2 to the first lithium salt is 1:2), and the Dv 50 nanopowder LATP with a particle size of 300 nm (the mass ratio of the nanopowder LATP to the first lithium salt is 1:6). The first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte, and the first inorganic oxide particles are mixed and stirred for 3 h to obtain an electrolyte separator slurry on the positive electrode side. The electrolyte separator slurry on the positive electrode side is cast on the surface of the positive electrode, and hot pressing is performed to obtain the positive electrode side electrolyte separator.

[0093] Embodiment 3

[0094] In the positive electrode side electrolyte separator provided in Embodiment 3 of the present application, lithium bis(trifluorosulfonylimide) (Li(CF3SO2)2N) and polyvinylidene fluoride (PVDF) are mixed at a mass ratio of 1:6. After melt mixing, titanium oxide (TiO2) is added (the mass ratio of TiO2 to the first lithium salt is 1:2), and the Dv 50For 200nm nanometer powder LLZTO (the mass ratio of the first lithium salt is 1:4), the first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte, and the first inorganic oxide particles are mixed and stirred for 5h to obtain the electrolyte diaphragm slurry of the positive electrode side, the electrolyte diaphragm slurry of the positive electrode side is cast on the positive electrode surface, and the positive electrode side electrolyte diaphragm is obtained by hot pressing.

[0095] Example 4

[0096] The positive electrode side electrolyte diaphragm provided by the example 4 of the present application, lithium tetrafluoroborate (LiBF4), lithium difluorobisoxalate phosphate (LiDFPBOP) are mixed in a mass ratio of 1:0.5 to obtain the first lithium salt; the first lithium salt and polyimide (PI) are mixed in a mass ratio of 1:3, and then put into a banbury mixer for melt mixing, and after melting, zirconium oxide (ZrO2) (the mass ratio of the first lithium salt is 1:500) is added, and the Dv 50 For 100nm nanometer powder lithium aluminum germanium phosphate (LAGP) (the mass ratio of the first lithium salt is 1:500), the first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte, and the first inorganic oxide particles are mixed and stirred for 3h to obtain the electrolyte diaphragm slurry of the positive electrode side, the electrolyte diaphragm slurry of the positive electrode side is cast on the positive electrode surface, and the positive electrode side electrolyte diaphragm is obtained by hot pressing.

[0097] Example 5

[0098] The positive electrode side electrolyte diaphragm provided by the example 5 of the present application, lithium bis(oxalato)borate (LiBOB), lithium difluorobisoxalate phosphate (LiDFPBOP) are mixed in a mass ratio of 1:3 to obtain the first lithium salt; the first lithium salt and the polymer polycaprolactone (PCL) are mixed in a mass ratio of 1:8, and then put into a banbury mixer for melt mixing, and after melting, boehmite (the mass ratio of the first lithium salt is 1:1) is added, and the Dv 50 For 900nm nanometer powder lithium phosphorus sulfur chloride (LPSCl) (the mass ratio of the first lithium salt is 1:1), the first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte, and the first inorganic oxide particles are mixed and stirred for 5h to obtain the electrolyte diaphragm slurry of the positive electrode side, the electrolyte diaphragm slurry of the positive electrode side is cast on the positive electrode surface, and the positive electrode side electrolyte diaphragm is obtained by hot pressing.

[0099] Example 6

[0100] Embodiment 6 of the present application provides a positive electrode side electrolyte diaphragm, lithium difluorophosphate (LiPO2F2) and lithium bis(trifluorosulfonyl)imide (Li(CF3SO2)2N) are mixed in a mass ratio of 1:0.3 to obtain a first lithium salt; the first lithium salt and a polymer polyvinylidene fluoride-hexafluoropropylene (PVDF-HFP) are mixed in a mass ratio of 1:2, and then put into a banbury mixer for melt mixing, after melting, manganese dioxide (MnO2) (mass ratio of 1:600 with the first lithium salt) and Dv 50 a nanometer powder bromide (Li3YBr6) with a particle size of 50 nm (mass ratio of 1:600 with the first lithium salt) are added, the first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte and the first inorganic oxide particles are mixed and stirred for 2 h to obtain a positive electrode side electrolyte diaphragm slurry, and the positive electrode side electrolyte diaphragm slurry is cast on the surface of the positive electrode and hot-pressed to obtain the positive electrode side electrolyte diaphragm.

[0101] Embodiment 7

[0102] Embodiment 7 of the present application provides a positive electrode side electrolyte diaphragm, lithium difluorophosphate (LiPO2F2) and lithium difluorobisoxalate phosphate (LiDFPBOP) are mixed in a mass ratio of 1:5 to obtain a first lithium salt; the first lithium salt and a polymer polyimide (PI) are mixed in a mass ratio of 1:10, and then put into a banbury mixer for melt mixing, after melting, aluminum oxide (Al2O3) (mass ratio of 2:1 with the first lithium salt) and Dv 50 a nanometer powder tantalum-doped lithium lanthanum zirconium oxide (LLZTO) with a particle size of 950 nm (mass ratio of 2:1 with the first lithium salt) are added, the first lithium salt, the first organic polymer, the first inorganic nanometer solid electrolyte and the first inorganic oxide particles are mixed and stirred for 6 h to obtain a positive electrode side electrolyte diaphragm slurry, and the positive electrode side electrolyte diaphragm slurry is cast on the surface of the positive electrode and hot-pressed to obtain the positive electrode side electrolyte diaphragm.

[0103] Embodiment 8

[0104] Embodiment 8 of the present application provides a negative electrode side electrolyte diaphragm, lithium bisfluorosulfonylimide (Li(SO2F)2N) and lithium perchlorate (LiClO4) are mixed in a mass ratio of 1:1 to obtain a second lithium salt, the second lithium salt and a polymer polyethylene oxide (PEO) are mixed in a mass ratio of 1:4, and then put into a banbury mixer for melt mixing, after melting, silicon oxide (SiO2) (mass ratio of 1:4 with the second lithium salt) and Dv 50 a nanometer powder LATP with a particle size of 400 nm (mass ratio of 1:4 with the second lithium salt) are added, the second lithium salt, the second organic polymer, the second inorganic nanometer solid electrolyte and the second inorganic oxide particles are mixed and stirred for 3 h to obtain a negative electrode side electrolyte diaphragm slurry, and the negative electrode side electrolyte diaphragm slurry is cast on the surface of the lithium metal negative electrode and hot-pressed to obtain the negative electrode side electrolyte diaphragm.

[0105] Example 9

[0106] The example 9 of the present application provides a negative electrode side electrolyte separator. Polyethylene oxide (PEO) and polypropylene carbonate (PPC) are mixed in a mass ratio of 1:1 to obtain a second organic polymer. Lithium bisfluorosulfonylimide (Li(SO2F)2N) is mixed with the second organic polymer in a mass ratio of 1:6. After melting and mixing, titanium oxide (TiO2) (mass ratio of 1:5 with respect to the second lithium salt) and Dv 50 The second lithium salt, the second organic polymer, the second inorganic nano solid-state electrolyte, and the second inorganic oxide particles are mixed and stirred for 4 h, to obtain a negative electrode side electrolyte separator slurry. The negative electrode side electrolyte separator slurry is cast on the surface of a lithium metal negative electrode, and the negative electrode side electrolyte separator is hot-pressed.

[0107] Example 10

[0108] The example 10 of the present application provides a negative electrode side electrolyte separator. Polyethylene oxide (PEO) and polypropylene carbonate (PPC) are mixed in a mass ratio of 1:1 to obtain a second organic polymer. Lithium bisfluorosulfonylimide (Li(SO2F)2N) is mixed with the second organic polymer in a mass ratio of 1:6. After melting and mixing, titanium oxide (TiO2) (mass ratio of 1:5 with respect to the second lithium salt) and Dv 50 The second lithium salt, the second organic polymer, the second inorganic nano solid-state electrolyte, and the second inorganic oxide particles are mixed and stirred for 4 h, to obtain a negative electrode side electrolyte separator slurry. The negative electrode side electrolyte separator slurry is cast on the surface of a lithium metal negative electrode, and the negative electrode side electrolyte separator is hot-pressed.

[0109] Example 11

[0110] The example 11 of the present application provides a negative electrode side electrolyte separator. Lithium bis(oxalato)borate (LiBOB) and lithium difluorobis(oxalato)phosphate (LiDFPBOP) are mixed in a mass ratio of 1:0.5 to obtain a second lithium salt. The second lithium salt is mixed with polymeric polyethylene glycol dimethacrylate (PEGDMA) in a mass ratio of 1:3. After mixing, it is put into a mixing mill for melting and mixing. After melting, manganese dioxide (MnO2) (mass ratio of 1:500 with respect to the second lithium salt) and Dv 50For 100nm nanopowder chloride (Li3InCl5) (mass ratio of 1:500 with the second lithium salt), the second lithium salt, the second organic polymer, the second inorganic nanometer solid electrolyte, the second inorganic oxide particles are mixed and stirred for 2.5h to obtain the negative electrode side electrolyte diaphragm slurry, the negative electrode side electrolyte diaphragm slurry is cast on the surface of the lithium metal negative electrode, and the negative electrode side electrolyte diaphragm is hot pressed.

[0111] Embodiment 12

[0112] The embodiment 12 of the present application provides a negative electrode side electrolyte diaphragm, lithium difluoro(oxalato)borate (LiDFOB), lithium difluorophosphate (LiPO2F2) are mixed in a mass ratio of 1:4 to obtain a second lithium salt, and the second lithium salt is mixed with a polymer polypropylene carbonate (PPC) in a mass ratio of 1:8, and then put into a mixer for melt mixing, and then calcium oxide (CaO) (mass ratio of 1:1 with the second lithium salt), Dv 50 For 900nm nanopowder lithium aluminum germanium phosphate (LAGP) (mass ratio of 1:1 with the second lithium salt), the second lithium salt, the second organic polymer, the second inorganic nanometer solid electrolyte, the second inorganic oxide particles are mixed and stirred for 5.5h to obtain the negative electrode side electrolyte diaphragm slurry, the negative electrode side electrolyte diaphragm slurry is cast on the surface of the lithium metal negative electrode, and the negative electrode side electrolyte diaphragm is hot pressed.

[0113] Embodiment 13

[0114] The embodiment 13 of the present application provides a negative electrode side electrolyte diaphragm, polyvinyl chloride (PVC), acrylonitrile (SN) are mixed in a mass ratio of 1:0.2 to obtain a second organic polymer, lithium hexafluorophosphate (LiPF6) is mixed with the second organic polymer in a mass ratio of 1:2, and then zirconium oxide (ZrO2) (mass ratio of 1:600 with the second lithium salt), Dv 50 For 50nm nanopowder LLZTO (mass ratio of 1:600 with the second lithium salt), the second lithium salt, the second organic polymer, the second inorganic nanometer solid electrolyte, the second inorganic oxide particles are mixed and stirred for 2h to obtain the negative electrode side electrolyte diaphragm slurry, the negative electrode side electrolyte diaphragm slurry is cast on the surface of the lithium metal negative electrode, and the negative electrode side electrolyte diaphragm is hot pressed.

[0115] Embodiment 14

[0116] The embodiment 14 of the present application provides a negative electrode side electrolyte diaphragm, polyethylene glycol (PEG), polymethyl methacrylate (PMMA) are mixed in a mass ratio of 1:5 to obtain a second organic polymer, lithium tetrafluoroborate (LiBF4) is mixed with the second organic polymer in a mass ratio of 1:10, and then titanium oxide manganese dioxide (MnO2) (mass ratio of 2:1 with the second lithium salt), Dv50 For 950nm nano-powder lithium lanthanum zirconium oxide (LLZO) (mass ratio of 2:1 with the second lithium salt), the second lithium salt, the second organic polymer, the second inorganic nano solid-state electrolyte, and the second inorganic oxide particles are mixed and stirred for 6h to obtain a negative electrode side electrolyte separator slurry, the negative electrode side electrolyte separator slurry is cast on the surface of the lithium metal negative electrode, and the negative electrode side electrolyte separator is hot-pressed.

[0117] Example 15

[0118] The application embodiment 15 provides a lithium metal battery, comprising a positive electrode, a solid-state electrolyte layer and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with the positive electrode side electrolyte separator as described in the embodiment 1, and the negative electrode and the solid-state electrolyte layer are provided with the negative electrode side electrolyte separator as described in the embodiment 8.

[0119] The thickness ratio of the positive electrode side electrolyte separator, the solid-state electrolyte layer and the negative electrode side electrolyte separator is 1:1:2, the thickness of the solid-state electrolyte layer is 20μm, and the material of the solid-state electrolyte layer is inorganic nano solid-state electrolyte (LATP), Dv 50 is 200nm.

[0120] Example 16

[0121] The application embodiment 16 provides a lithium metal battery, comprising a positive electrode, a solid-state electrolyte layer and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with the positive electrode side electrolyte separator as described in the embodiment 2, and the negative electrode and the solid-state electrolyte layer are provided with the negative electrode side electrolyte separator as described in the embodiment 9.

[0122] The thickness ratio of the positive electrode side electrolyte separator, the solid-state electrolyte layer and the negative electrode side electrolyte separator is 1:1:1, the thickness of the solid-state electrolyte layer is 25μm, and the material of the solid-state electrolyte layer is inorganic nano solid-state electrolyte (LATP), Dv 50 is 300nm.

[0123] Example 17

[0124] The application embodiment 17 provides a lithium metal battery, comprising a positive electrode, a solid-state electrolyte layer and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with the positive electrode side electrolyte separator as described in the embodiment 3, and the negative electrode and the solid-state electrolyte layer are provided with the negative electrode side electrolyte separator as described in the embodiment 10.

[0125] The thickness ratio of the positive electrode side electrolyte separator, the solid-state electrolyte layer and the negative electrode side electrolyte separator is 1.5:1:1.5, the thickness of the solid-state electrolyte layer is 20μm, and the material of the solid-state electrolyte layer is inorganic nano solid-state electrolyte (LLZTO), Dv 50 is 200nm.

[0126] Embodiment 18

[0127] The embodiment 18 provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in the embodiment 4, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in the embodiment 11.

[0128] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer and the negative electrode side electrolyte separator is 1:1:0.5, the thickness of the solid electrolyte layer is 50 μm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte lithium aluminum titanium phosphate (LATP), Dv 50 400 nm.

[0129] Embodiment 19

[0130] The embodiment 19 provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in the embodiment 5, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in the embodiment 12.

[0131] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer and the negative electrode side electrolyte separator is 2:1:2, the thickness of the solid electrolyte layer is 5 μm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte lithium aluminum germanium phosphate (LAGP), Dv 50 400 nm.

[0132] Embodiment 20

[0133] The embodiment 20 provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in the embodiment 6, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in the embodiment 13.

[0134] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer and the negative electrode side electrolyte separator is 0.8:1:0.4, the thickness of the solid electrolyte layer is 5 μm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte lithium germanium phosphorus sulfide (LGPS), Dv 50 50 nm.

[0135] Embodiment 21

[0136] Embodiment 21 of the present application provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in Embodiment 7, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in Embodiment 14.

[0137] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer and the negative electrode side electrolyte separator is 2.5:1:2.5, the thickness of the solid electrolyte layer is 60 μm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte lithium phosphorus sulfur chloride (LPSCl), Dv 50 is 950 nm.

[0138] Embodiment 22

[0139] Embodiment 22 of the present application provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in Embodiment 6, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in Embodiment 11.

[0140] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer and the negative electrode side electrolyte separator is 0.8:1:1.5, the thickness of the solid electrolyte layer is 10 μm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte (LLZTO), Dv 50 is 400 nm.

[0141] Embodiment 23

[0142] Embodiment 23 of the present application provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in Embodiment 7, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in Embodiment 11.

[0143] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer and the negative electrode side electrolyte separator is 2.5:1:0.8, the thickness of the solid electrolyte layer is 40 μm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte (LLZTO), Dv 50 is 500 nm.

[0144] Embodiment 24

[0145] Embodiment 24 of the present application provides a lithium metal battery, comprising a positive electrode, a solid electrolyte layer and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in Embodiment 4, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in Embodiment 13.

[0146] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer, and the negative electrode side electrolyte separator is 1.5:1:0.4, the thickness of the solid electrolyte layer is 10 pm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte (LLZTO), Dv 50 is 400 nm.

[0147] Example 25

[0148] The lithium metal battery provided in Example 25 includes a positive electrode, a solid electrolyte layer, and a negative electrode, wherein the positive electrode and the solid electrolyte layer are provided with the positive electrode side electrolyte separator as described in Example 4, and the negative electrode and the solid electrolyte layer are provided with the negative electrode side electrolyte separator as described in Example 14.

[0149] The thickness ratio of the positive electrode side electrolyte separator, the solid electrolyte layer, and the negative electrode side electrolyte separator is 1:1:2.5, the thickness of the solid electrolyte layer is 40 pm, and the material of the solid electrolyte layer is inorganic nano solid electrolyte (LLZTO), Dv 50 is 500 nm.

[0150] Comparative Example 1

[0151] The positive electrode side electrolyte separator provided in Comparative Example 1 is similar to Example 4, except that the first polymer is polylactic acid (PLA), which has no anti-oxidation and anti-reduction properties.

[0152] Comparative Example 2

[0153] The positive electrode side electrolyte separator provided in Comparative Example 2 is similar to Example 4, except that the first polymer is polypropylene carbonate (PPC), which has anti-reduction properties.

[0154] Comparative Example 3

[0155] The negative electrode side electrolyte separator provided in Comparative Example 3 is similar to Example 11, except that the second polymer is polyethylene terephthalate glycol (PETG), which has no anti-reduction and anti-oxidation properties.

[0156] Comparative Example 4

[0157] The negative electrode side electrolyte separator provided in Comparative Example 4 is similar to Example 11, except that the second polymer is polyvinylidene fluoride (PVDF), which has anti-oxidation properties.

[0158] Comparative Example 5

[0159] The lithium metal battery of the present application Comparative Example 5 is similar to Example 18, except that it comprises a positive electrode, a solid-state electrolyte layer, and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with a positive electrode side electrolyte separator as described in Comparative Example 1, and the negative electrode and the solid-state electrolyte layer are provided with a negative electrode side electrolyte separator as described in Example 4.

[0160] Comparative Example 6

[0161] The lithium metal battery of the present application Comparative Example 6 is similar to Example 18, except that it comprises a positive electrode, a solid-state electrolyte layer, and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with a positive electrode side electrolyte separator as described in Comparative Example 2, and the negative electrode and the solid-state electrolyte layer are provided with a negative electrode side electrolyte separator as described in Example 4.

[0162] Comparative Example 7

[0163] The lithium metal battery of the present application Comparative Example 7 is similar to Example 18, except that it comprises a positive electrode, a solid-state electrolyte layer, and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with a positive electrode side electrolyte separator as described in Example 4, and the negative electrode and the solid-state electrolyte layer are provided with a negative electrode side electrolyte separator as described in Comparative Example 3.

[0164] Comparative Example 8

[0165] The lithium metal battery of the present application Comparative Example 8 is similar to Example 18, except that it comprises a positive electrode, a solid-state electrolyte layer, and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with a positive electrode side electrolyte separator as described in Example 4, and the negative electrode and the solid-state electrolyte layer are provided with a negative electrode side electrolyte separator as described in Comparative Example 4.

[0166] Comparative Example 9

[0167] The lithium metal battery of the present application Comparative Example 9 is similar to Example 18, except that it comprises a positive electrode, a solid-state electrolyte layer, and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with a positive electrode side electrolyte separator as described in Comparative Example 1, and the negative electrode and the solid-state electrolyte layer are provided with a negative electrode side electrolyte separator as described in Comparative Example 3.

[0168] Comparative Example 10

[0169] The lithium metal battery of the present application Comparative Example 10 is similar to Example 18, except that it comprises a positive electrode, a solid-state electrolyte layer, and a negative electrode, wherein the positive electrode and the solid-state electrolyte layer are provided with a positive electrode side electrolyte separator as described in Comparative Example 2, and the negative electrode and the solid-state electrolyte layer are provided with a negative electrode side electrolyte separator as described in Comparative Example 4.

[0170] Comparative Example 11

[0171] The lithium metal battery of the present application Comparative Example 11 is similar to Example 18, except that the positive side electrolyte separator does not contain the first inorganic nano-solid-state electrolyte and the first inorganic oxide particles.

[0172] Comparative Example 12

[0173] The lithium metal battery of the present application Comparative Example 12 is similar to Example 18, except that the negative side electrolyte separator does not contain the second inorganic nano-solid-state electrolyte and the second inorganic oxide particles.

[0174] Comparative Example 13

[0175] The lithium metal battery of the present application Comparative Example 13 is similar to Example 18, except that the positive side electrolyte separator does not contain the first inorganic nano-solid-state electrolyte and the first inorganic oxide particles, and the negative side electrolyte separator does not contain the second inorganic nano-solid-state electrolyte and the second inorganic oxide particles.

[0176] Comparative Example 14

[0177] The lithium metal battery of the present application Comparative Example 14 is similar to Example 18, except that the material of the first polymer of the positive side electrolyte separator is polyacrylonitrile (PAN) and succinonitrile (SN) at a mass ratio of 1:1, and the material of the second polymer of the negative side electrolyte separator is polyacrylonitrile (PAN) and succinonitrile (SN) at a mass ratio of 1:1.

[0178] Performance test

[0179] The lithium metal batteries of Examples 15-25 and the lithium metal batteries of Comparative Examples 5-14 were subjected to performance tests to test their battery electrical performance, and the specific test methods were as follows:

[0180] Capacity retention rate: the discharge specific capacity value of the 100th week cycle was selected compared to the rated capacity value, and the result was displayed in percentage mode, i.e., the capacity retention rate.

[0181] Coulombic efficiency: the discharge capacity value of each week was selected compared to the charge capacity value of each week, and the result was displayed in percentage mode, i.e., the coulombic efficiency.

[0182] DCIR: the DCIR of the battery is tested by the HPPC method, 1. first, the battery is rested for 5 min; 2. discharged at 0.33C to 2.5V (1C current is 6.5A), 3. rested for 30 min and then charged to 4.2V in the constant current mode at 0.33C, and then charged to 4.2V in the constant voltage mode, and the charging current is less than 0.05C to end this step; 4. rested for 30 min and then discharged in the constant current mode at 0.33C, and the cut-off voltage is set to 2.5V, and rested for 30 min; then repeat steps 3 and 4 once, and take the discharge capacity C0 of the second time as the actual capacity of the battery; adjust the SOC, and charge to 4.2V in the constant current mode at 0.33C, and then charge to 4.2V in the constant voltage mode, and the charging current is less than 0.05C to end this step, and discharge 0.1C0 (the capacity charged and discharged in the pulse process needs to be counted) at 0.33C0, and adjust to the target SOC, and discharge at 0.2C0 or constant voltage when the SOC is lower than 20%; rested for 30 min, and then discharge at 3C0 for 10s; (the lower limit voltage is 2.5V) record the voltage V2, V1 and the current I2, I1 before and after discharging; the direct current resistance R is (V2-V1) / (I2-I1).

[0183] ACR: the AC impedance of the battery is directly tested by the ZX5560B model of the Zichen Precision Instrument Co., Ltd.

[0184] The specific composition of the positive plate is described by way of example as follows: NCM8 system, conductive agent carbon nanotube, and adhesive polyvinylidene fluoride (PVDF), and the mass ratio is 96:2:2.

[0185] The negative plate is a lithium metal negative electrode.

[0186] The assembly of the lithium metal battery is described by way of example as follows: the battery is assembled in the lamination mode, the positive electrode is coated on both sides, and the appearance is packaged with an aluminum plastic film.

[0187] The specific test results are shown in Table 1.

[0188] Table 1 Performance of lithium metal batteries of Examples 15 to 25 and Comparative Examples 5 to 14

[0189]

[0190] As shown in Table 1, the solid-state batteries of Examples 15 to 25 have obvious advantages in cycle capacity retention rate, coulombic efficiency, direct current impedance and alternating current impedance compared with the solid-state batteries of Comparative Examples 5 to 14. The capacity retention rate and coulombic efficiency performance chart of the lithium metal battery of Example 15 is shown in Figure 2 . The capacity retention rate and coulombic efficiency performance chart of the lithium metal battery of Example 16 is shown in Figure 3The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 17 are shown in FIG. 17. Figure 4 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 18 are shown in FIG. 18. Figure 5 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 19 are shown in FIG. 19. Figure 6 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 20 are shown in FIG. 20. Figure 7 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 21 are shown in FIG. 21. Figure 8 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 22 are shown in FIG. 22. Figure 9 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 23 are shown in FIG. 23. Figure 10 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 24 are shown in FIG. 24. Figure 11 The capacity retention and coulombic efficiency performance plots of the lithium metal batteries of Example 25 are shown in FIG. 25. Figure 12 It can be seen that Examples 15-17 have lower DC internal resistance and AC internal resistance, and the lower DC internal resistance helps to reduce heat generation during charging and discharging, and the low DC internal resistance also helps to improve the fast charging capability of the battery. In contrast, the internal resistance of Examples 18 and 19 is higher than that of Examples 15-17, and the corresponding heat generation is more, so the cycle performance and fast charging performance are inferior to Examples 15-17. Through data comparison, it can be found that the cycle capacity retention of Examples 15-19 is significantly better than that of Examples 20-25, and the corresponding DC internal resistance of Examples 15-19 is significantly lower than that of Examples 20-25. Examples 20-25 have higher DC internal resistance, and the fast charging performance is slightly worse than that of Examples 15-19, and the heat generation is more serious than that of Examples 15-19.

[0191] Example 20 has inorganic nano solid-state electrolyte lithium germanium phosphorus sulfur (LGPS) with a Dv 50 The particle size between the particles is small, which may cause agglomeration and slightly affect the performance of the battery, so the performance is slightly lower than that of Examples 15-19, but still better than that of Comparative Examples 5-14.

[0192] Example 21 has a thicker thickness of the positive electrode side electrolyte separator, the solid-state electrolyte layer and the negative electrode side electrolyte separator, which causes higher internal resistance, and the larger particle size of the inorganic nano solid-state electrolyte has a certain influence on the electrochemical reaction speed; which leads to a certain decay of the battery performance, so the performance is slightly lower than that of Examples 15-20, but still better than that of Comparative Examples 5-14.

[0193] In Example 22, due to the lower thickness of the organic-inorganic electrolyte membrane on the positive electrode side, the mechanical strength and thermal stability decreased to varying degrees. Therefore, the performance was slightly lower than that of Examples 15 to 20, but it was still better than Comparative Examples 5 to 14.

[0194] In Example 23, due to the larger thickness of the organic-inorganic electrolyte membrane on the positive electrode side, the corresponding electrochemical impedance will increase and the ion conduction ability will decrease to a certain extent. Therefore, the performance is slightly lower than that of Examples 15 to 20, but it is still better than Comparative Examples 5 to 14.

[0195] In Example 24, due to the lower thickness of the organic-inorganic electrolyte membrane on the negative electrode side, the mechanical strength and thermal stability decreased to varying degrees. Therefore, the performance was slightly lower than that of Examples 15 to 20, but it was still better than Comparative Examples 5 to 14.

[0196] In Example 25, due to the larger thickness of the organic-inorganic electrolyte membrane on the negative electrode side, the corresponding electrochemical impedance will increase and the ion conduction ability will decrease to a certain extent. Therefore, the performance is slightly lower than that of Examples 15 to 20, but it is still better than Comparative Examples 5 to 14.

[0197] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 5 are shown in the figure below. Figure 13 As shown in the figure. In Comparative Example 5, the first polymer of the electrolyte separator on the positive electrode side has no antioxidant or reduction resistance, resulting in poor contact at the positive electrode interface, high contact resistance, and inability to suppress internal side reactions of the battery.

[0198] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 6 are shown in the figure below. Figure 14 As shown in the figure. In Comparative Example 6, the first polymer of the electrolyte membrane on the positive electrode side has anti-reduction properties, thus exhibiting poor antioxidant properties on the positive electrode side and an inability to suppress side reactions.

[0199] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 7 are shown in the figure below. Figure 15 As shown in the figure. In Comparative Example 7, the second polymer of the electrolyte separator on the negative electrode side has no antioxidant or reduction resistance, resulting in poor contact at the positive electrode interface, high contact resistance, and inability to suppress internal side reactions of the battery.

[0200] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 8 are shown in the figure below. Figure 16 As shown. In Comparative Example 8, the second polymer of the electrolyte membrane on the negative electrode side has antioxidant properties, thus exhibiting poor resistance to reduction on the negative electrode side and an inability to suppress side reactions.

[0201] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 9 are shown in the figure below. Figure 17As shown in Comparative Example 9, due to the lack of antioxidant and reduction resistance of the first polymer in the electrolyte separator on the positive electrode side and the lack of antioxidant and reduction resistance of the second polymer in the electrolyte separator on the negative electrode side, there are defects such as poor contact at the positive and negative electrode interfaces, large contact resistance, and inability to suppress internal side reactions of the battery.

[0202] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 10 are shown in the figure below. Figure 18 As shown. In Comparative Example 10, because the first polymer of the electrolyte separator on the positive electrode side has anti-reduction properties and the second polymer of the electrolyte separator on the negative electrode side has anti-oxidation properties, there is a defect that it cannot suppress the internal side reactions of the battery.

[0203] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 11 are shown in the figure below. Figure 19 As shown. In Comparative Example 11, the electrolyte membrane on the positive electrode side does not contain the first inorganic nano-solid electrolyte and the first inorganic oxide particles, thus exhibiting defects such as poor mechanical properties, poor thermal stability, and deterioration of electrical properties.

[0204] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 12 are shown in the figure below. Figure 20 As shown. Comparative Example 12 has defects such as poor mechanical properties, poor thermal stability, and deterioration of electrical properties because the electrolyte membrane on the negative electrode side does not contain the second inorganic nano-solid electrolyte and the second inorganic oxide particles.

[0205] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 13 are shown in the figure below. Figure 21 As shown. Comparative Example 13 has defects such as poor mechanical properties, poor thermal stability, poor thermodynamic stability, and deterioration of electrical properties because the electrolyte membrane on the positive electrode side does not contain the first inorganic nano-solid electrolyte and the first inorganic oxide particles, and the electrolyte membrane on the negative electrode side does not contain the second inorganic nano-solid electrolyte and the second inorganic oxide particles.

[0206] The capacity retention and coulombic efficiency performance of the lithium metal battery in Comparative Example 14 are shown in the figure below. Figure 22 As shown. In Comparative Example 14, since the first polymer of the electrolyte membrane on the positive electrode side is polyacrylonitrile (PAN) and succinic acid (SN) in a mass ratio of 1:1, and the second polymer of the electrolyte membrane on the negative electrode side is polyacrylonitrile (PAN) and succinic acid (SN) in a mass ratio of 1:1, it has the defects of poor resistance to reduction and inability to suppress side reactions.

[0207] In summary, by using the organic polymer with antioxidant properties, the first lithium salt and the first inorganic oxide particles as the positive electrode side electrolyte separator, the flexible characteristics of the organic solid-state electrolyte are used to reduce the contact resistance, the risk of internal side reactions is reduced, the rapid conduction of lithium ions is ensured, the formation of lithium dendrites is inhibited, and the safety and energy density of the battery are improved. The organic polymer with antioxidant properties can exist stably during the battery charging and discharging reaction process. Such organic polymers have strong antioxidant properties and are not easy to lose electrons. In the electrochemical reaction inside the battery, they will not lose electrons before the positive electrode to cause side reactions, i.e., have a lower highest occupied molecular orbital (HOMO). At the same time, such organic polymers have good flexibility, which can reduce the contact resistance and have a lower cost. The first lithium salt can form an organic polymer electrolyte with the organic polymer, providing conditions for lithium ion migration. The introduction of lithium salt ensures the ion conduction of the positive electrode side and provides a basis for the electrochemical reaction of the battery. The first inorganic oxide particles can reduce the crystallinity of the organic polymer. In general, the organic polymer with antioxidant properties has a certain degree of crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order of the crystalline region, thereby increasing the lithium ion conduction area and further improving the electrical performance. The first inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure rapid conduction of lithium ions, and reduce electrochemical polarization effect. Moreover, due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side can be effectively improved, eliminating the thermal shrinkage of the electrolyte caused by the heat generated by the electrochemical reaction. Not only does it improve the efficiency of lithium ion transport, but it also improves the thermal runaway and mechanical damage inside the battery to varying degrees.

[0208] The second organic polymer with anti-reduction performance can exist stably in the electrochemical reaction, and the second organic polymer has a higher lowest unoccupied molecular orbital (LUMO), and due to this characteristic, it is not easy to obtain electrons in the electrochemical reaction, so the second organic polymer will not preferentially obtain electrons at the negative electrode side, and will not cause side reactions to affect the normal charge and discharge reactions of the battery cell. At the same time, the second lithium salt is added to form an organic polymer electrolyte and complete the construction of the lithium ion transmission channel. However, due to the existence of a large number of crystalline regions in the organic polymer, the second inorganic nano solid-state electrolyte is added to increase the proportion of amorphous regions in the polymer and increase the effective lithium ion transmission area concentration. Moreover, the introduction of the inorganic nano solid-state electrolyte can increase the lithium ion transmission channel and increase the lithium ion migration path, further improving the electrical performance. For the electrolyte material on the negative electrode side, not only excellent electrical performance is required, but also high mechanical strength is required to inhibit the formation of lithium dendrites. Therefore, the second inorganic oxide particles are added to improve the mechanical properties of the organic-inorganic composite electrolyte on the negative electrode side. Moreover, the organic-inorganic electrolyte itself has good flexibility, which can better contact with the electrode material, especially the lithium metal negative electrode, which can effectively reduce the contact resistance and improve the cycle performance and fast charging performance of the solid-state lithium metal battery. The second lithium salt can form an organic polymer electrolyte with the organic polymer to provide conditions for lithium ion migration, and the introduction of the lithium salt ensures the ion conduction on the positive electrode side and provides a basis for the electrochemical reaction of the battery. The first inorganic oxide particles can reduce the crystallinity of the organic polymer. Generally, organic polymers with oxidation resistance have a certain degree of crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction region and further improving the electrical performance. The first inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure fast lithium ion conduction, and reduce electrochemical polarization effect. Moreover, due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side can be effectively improved, and the thermal contraction of the electrolyte caused by the heat generated by the electrochemical reaction can be eliminated, which not only improves the lithium ion transmission efficiency but also improves the thermal runaway and mechanical damage inside the battery to different degrees. The second inorganic oxide particles can reduce the crystallinity of the organic polymer. Generally, organic polymers with oxidation resistance have a certain degree of crystallinity, and ion migration generally occurs in the amorphous region of the polymer. Therefore, the addition of inorganic oxide particles can destroy the order degree of the crystalline region, thereby increasing the lithium ion conduction region and further improving the electrical performance.The second inorganic nano solid-state electrolyte can provide more channels for lithium ion migration, ensure fast conduction of lithium ions, reduce electrochemical polarization effect, and effectively improve the thermal stability and mechanical strength of the organic-inorganic composite electrolyte on the positive electrode side due to the good mechanical properties and thermal stability of the inorganic nano solid-state electrolyte, eliminate thermal shrinkage of the electrolyte caused by electrochemical reaction heat, not only improve the lithium ion transmission efficiency but also prevent internal thermal runaway of the battery, and inhibit the formation of lithium dendrites.

[0209] In the description of the present specification, the description of the terms "one embodiment / way", "some embodiments / ways", "example", "specific example" or "some examples" and the like means that the specific features, structures, materials or characteristics described in connection with the embodiment / way or example are included in at least one embodiment / way or example of the present application. In the present specification, the illustrative description of the above terms does not necessarily refer to the same embodiment / way or example. Moreover, the specific features, structures, materials or characteristics described can be combined in any appropriate manner in any one or more embodiments / ways or examples. In addition, the person skilled in the art can combine and combine the different embodiments / ways or examples described in the present specification and the features of the different embodiments / ways or examples without contradiction.

[0210] It should be noted that in the present application, the relationship terms such as "first" and "second" are only used to distinguish one entity or operation from another entity or operation, and do not necessarily require or imply any such actual relationship or order between the entities or operations. Moreover, the terms "include", "contain" or any other variant thereof are intended to cover non-exclusive inclusion, so that the process, method, article or device including a series of elements not only includes those elements, but also includes other elements not explicitly listed or inherent to such process, method, article or device. Without more limitations, the element defined by the statement "including a" does not exclude the presence of another identical element in the process, method, article or device including the element. In the present application, the meaning of "a plurality of" is at least two, for example, two, three, etc., unless otherwise explicitly specified.

[0211] The above is only a specific embodiment of the present application, which enables those skilled in the art to understand or implement the present application. Various modifications of these embodiments will be apparent to those skilled in the art, and the general principles defined herein can be implemented in other embodiments without departing from the spirit or scope of the present application. Therefore, the present application will not be limited to these embodiments shown herein, but will conform to the widest scope consistent with the principles and novel features applied herein.

Claims

1. A lithium metal battery, characterized in that, It includes a positive electrode, a solid electrolyte layer and a negative electrode, wherein: a positive electrode side electrolyte membrane is provided between the positive electrode and the solid electrolyte layer, and a negative electrode side electrolyte membrane is provided between the negative electrode and the solid electrolyte layer; The material of the positive electrode side electrolyte membrane includes a first organic polymer, a first lithium salt, a first inorganic nano-solid electrolyte, and first inorganic oxide particles, wherein: The first organic polymer includes an organic polymer with antioxidant properties; The mass ratio of the first organic polymer, the first lithium salt, the first inorganic nano-solid electrolyte, and the first inorganic oxide particles is (3~8):1:(0.002~1):(0.002~1). The material of the electrolyte membrane on the negative electrode side includes a second organic polymer, a second lithium salt, a second inorganic nano-solid electrolyte, and second inorganic oxide particles, wherein: The second organic polymer includes organic polymers with anti-reduction properties; The mass ratio of the second organic polymer, the second lithium salt, the second inorganic nano-solid electrolyte, and the second inorganic oxide particles is (3~8):1:(0.002~1):(0.002~1). The first organic polymer includes at least one of polyvinylidene fluoride, polyacrylonitrile, polyvinylidene fluoride-hexafluoropropylene, polycaprolactone, and polyimide; The second organic polymer includes at least one of polyethylene glycol, polyethylene oxide, polypropylene carbonate, polymethyl methacrylate, polyethylene glycol dimethacrylate, polyvinyl carbonate, and polypropylene oxide.

2. The lithium metal battery as described in claim 1, characterized in that: The first lithium salt comprises at least one of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium tetrafluoroborate, lithium bis(trifluorosulfonyl)imide, lithium dioxalate borate, lithium difluorooxalate borate, lithium difluorophosphate, and lithium difluorobis(oxalate) phosphate; and / or, The first inorganic oxide particles include at least one of aluminum oxide, silicon oxide, manganese dioxide, zirconium oxide, titanium oxide, boehmite, and calcium oxide; and / or, The first inorganic nano-solid electrolyte includes at least one of oxide electrolytes, sulfide electrolytes, and halide electrolytes.

3. The lithium metal battery as described in claim 1, characterized in that, The thickness of the electrolyte membrane on the positive electrode side is 5μm~80μm.

4. The lithium metal battery as described in claim 1, characterized in that: The second lithium salt comprises at least one of lithium hexafluorophosphate, lithium bis(fluorosulfonyl)imide, lithium perchlorate, lithium tetrafluoroborate, lithium bis(trifluorosulfonyl)imide, lithium dioxalate borate, lithium difluorooxalate borate, lithium difluorophosphate, and lithium difluorobis(oxalate) phosphate; and / or, The second inorganic oxide particles include at least one of alumina, silicon dioxide, manganese dioxide, zirconium oxide, titanium dioxide, boehmite, and calcium oxide; and / or, The second inorganic nano-solid electrolyte includes at least one of oxide electrolytes, sulfide electrolytes, and halide electrolytes.

5. The lithium metal battery as described in claim 1, characterized in that, The thickness of the electrolyte membrane on the negative electrode side is 10μm~40μm.

6. The lithium metal battery as described in claim 1, characterized in that: The thickness ratio of the positive electrode side electrolyte membrane, the solid electrolyte layer, and the negative electrode side electrolyte membrane is (1~2):1:(0.5~2); and / or, The thickness of the solid electrolyte layer is 5μm to 50μm.

7. The lithium metal battery as described in claim 6, characterized in that, The material of the solid electrolyte layer includes a third inorganic nano-solid electrolyte, which includes at least one of oxide electrolyte, sulfide electrolyte and halide electrolyte.

8. The lithium metal battery as described in claim 7, characterized in that, The third inorganic nano-solid electrolyte's Dv 50 The range is 100nm to 900nm.

9. The lithium metal battery as described in claim 1, characterized in that, The lithium metal battery operates at a temperature of -40℃ to 120℃.

10. An electrical appliance, characterized in that, Including the lithium metal battery as described in any one of claims 1 to 9.

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