Solid-state lithium battery

Abstract

The invention provides a solid-state lithium battery. The solid-state lithium battery comprises a negative electrode layer, a solid-state electrolyte layer and a positive electrode layer, the solid electrolyte layer includes a first solid electrolyte. The positive electrode layer includes an active material, a second solid electrolyte, a conductive additive and an adhesive. The material of the second solid electrolyte comprises oxygen-doped sulfide or lithium indium chloride and / or the material of the conductive additive comprises graphene.

Description

Technical Field

[0001] The present invention relates to a solid-state lithium battery. Background Art

[0002] Lithium batteries are currently widely used in energy storage devices, such as notebook computers, mobile phones, the electric vehicle industry, etc. Due to many problems existing in liquid lithium batteries, in recent years, the research on solid-state lithium batteries, which have no risks such as liquid leakage, volatilization, combustion and explosion, can reduce the chance of lithium dendrites penetrating the electrolyte to contact the positive and negative electrodes during the charge and discharge process, and have high ionic conductivity and high electrochemical window, has been increasingly emphasized.

[0003] Furthermore, in a solid-state lithium battery, there is a large interfacial contact resistance between the solid-solid of the electrode and the solid electrolyte, and side reactions may occur when the electrode contacts the solid electrolyte, etc., which will affect its electrochemical stability and electrical performance. Summary of the Invention

[0004] The present invention provides a solid-state lithium battery, which has good electrochemical stability and can also maintain electrical performance.

[0005] A solid-state lithium battery of the present invention includes a negative electrode layer, a solid electrolyte layer, and a positive electrode layer. The solid electrolyte layer includes a first solid electrolyte. The positive electrode layer includes an active material, a second solid electrolyte, a conductive additive, and an adhesive. The material of the second solid electrolyte includes oxygen-doped sulfide or lithium indium chloride (Li 3 InCl 6 ) and / or the material of the conductive additive includes graphene.

[0006] In an embodiment of the present invention, the above oxygen-doped sulfide includes Li 6 PS 5-x ClO x 、Li 6 PS 5-x BrO x 、Li 6 PS 5-x IO x and their combinations, where x = 0 to 1.

[0007] In an embodiment of the present invention, the weight ratio of the above second solid electrolyte to the total weight of the positive electrode layer is greater than 20 wt%.

[0008] In an embodiment of the present invention, the weight ratio of the above conductive additive to the total weight of the positive electrode layer is less than 20 wt%.

[0009] In an embodiment of the present invention, the weight ratio of the above active material to the total weight of the positive electrode layer is between 60 wt% and 80 wt%.

[0010] In an embodiment of the present invention, the weight ratio of the above-mentioned adhesive to the total weight of the positive electrode layer is between 1 wt% and 5 wt%.

[0011] In an embodiment of the present invention, the number of layers of the above-mentioned graphene material is between 3 layers and 20 layers.

[0012] In an embodiment of the present invention, the materials of the above-mentioned first solid electrolyte and the second solid electrolyte are the same.

[0013] In an embodiment of the present invention, the material of the above-mentioned conductive additive further includes carbon black, vapor-phase carbon fiber or carbon nanotube.

[0014] In an embodiment of the present invention, the material of the above-mentioned negative electrode layer includes lithium, indium or a combination thereof.

[0015] Based on the above, the solid-state lithium battery of the present invention at least through the design of the positive electrode layer, introduces the material of the second solid electrolyte with lower reactivity and / or the material of the conductive additive, so that it has good electrochemical stability while maintaining electrical performance.

[0016] To make the above features and advantages of the present invention more obvious and understandable, specific embodiments are hereinafter given and detailed descriptions are made in conjunction with the accompanying drawings as follows. Description of the Drawings

[0017] Figure 1 is an exploded schematic view of the solid-state lithium battery of the present invention.

[0018] Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 are charge-discharge curves of some examples.

[0019] Figure 10 is the initial charge-discharge curve of some examples.

[0020] Figure 11 is the discharge capacity curve of some examples.

[0021] Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 Discharge capacity and Coulomb efficiency curves of some examples.

[0022] Figure 16 is the AC impedance diagram of some examples. Detailed Description of the Invention

[0023] In the following detailed description, for purposes of illustration and not limitation, exemplary embodiments revealing specific details are set forth in order to provide a thorough understanding of the various principles of the present invention. However, it will be apparent to those of ordinary skill in the art that the present invention may be practiced in other embodiments that depart from the specific details disclosed herein. Additionally, descriptions of well-known devices, methods, and materials may be omitted so as not to obscure the description of the various principles of the present invention.

[0024] Unless otherwise specified, the term "between" used in this specification to define a numerical range is intended to cover the range equal to the endpoint values as well as the range between the endpoint values. For example, a dimension range between a first numerical value and a second numerical value means that the dimension range can cover the first numerical value, the second numerical value, and any numerical value between the first numerical value and the second numerical value.

[0025] The solid-state lithium battery of the present invention includes a negative electrode layer, a solid electrolyte layer, and a positive electrode layer. The solid electrolyte layer includes a first solid electrolyte, and the positive electrode layer includes an active material, a second solid electrolyte, a conductive additive, and an adhesive. In addition, the material of the second solid electrolyte includes an oxygen-doped sulfide or lithium indium chloride and / or the material of the conductive additive includes graphene. In other words, the present invention can improve the material of the second solid electrolyte in the positive electrode layer to include an oxygen-doped sulfide or lithium indium chloride, or the present invention can improve the material of the conductive additive in the positive electrode layer to include graphene, or the present invention can simultaneously improve the materials of the second solid electrolyte and the conductive additive in the positive electrode layer by the foregoing methods.

[0026] Accordingly, the solid-state lithium battery of the present invention, at least through the design of the positive electrode layer (such as the foregoing improvement methods), introduces materials of the second solid electrolyte and / or the conductive additive with lower reactivity, so that it has good electrochemical stability while maintaining electrical performance.

[0027] Furthermore, through oxygen doping, sulfides are less likely to react with other components in the solid-state lithium battery, lithium indium chloride can be used as a buffer layer, and graphene with fewer surface functional groups is also less likely to react with other components in the solid-state lithium battery. Therefore, selecting these materials can make the solid-state lithium battery have a high energy density and high cycle stability, which will be specifically illustrated by examples below.

[0028] In some embodiments, the oxygen-doped sulfide includes Li 6 PS 5-x ClO x 、Li 6 PS 5-x BrO x 、Li 6 PS 5-x IOx and combinations thereof, where 1 > x > 0, and the materials of the first solid electrolyte and the second solid electrolyte are the same to further enhance the stabilization effect. However, the present invention is not limited thereto, and the first solid electrolyte may also use or further include indium trichloride (InCl 3 ).

[0029] In some embodiments, the material of the conductive additive further includes carbon black, vapor-grown carbon fiber, or carbon nanotubes. That is, the conductive additive may simultaneously have a combination of graphene and any one of the above materials. For example, the conductive additive may have graphene and carbon black, or the conductive additive may have graphene and vapor-grown carbon fiber, or the conductive additive may have graphene and carbon nanotubes. Since materials such as carbon black have excellent electrical properties but are prone to adsorbing water molecules based on their characteristics, their electrochemical stability is not high when used alone. When used in synergy with graphene, good balance can be achieved in the electrochemical stability and electrical performance of the overall solid-state lithium battery through the characteristic that graphene is not prone to adsorbing water molecules. However, the present invention is not limited thereto.

[0030] In some embodiments, the number of layers of the graphene material is between 3 and 20 layers. However, the present invention is not limited thereto.

[0031] In some embodiments, graphene can be prepared using methods such as chemical oxidation delamination method, liquid-phase exfoliation method, ultrasonic method, chemical vapor deposition method, etc. However, the present invention is not limited thereto, and graphene can also be prepared using other suitable methods.

[0032] In some embodiments, the material of the negative electrode layer includes lithium, indium, or a combination thereof. For example, when the material of the negative electrode layer is a lithium-indium alloy, due to its low reactivity and passivation effect, the electrochemical stability of the solid-state lithium battery can be further improved. However, the present invention is not limited thereto.

[0033] In some embodiments, the active material includes polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 、 polycrystalline LiNi 0.6 Co 0.2 Mn 0.2 O 2 、 polycrystalline LiNi 0.5 Co 0.2 Mn 0.3 O 2 、 single-crystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 、 single-crystalline LiNi 0.6 Co 0.2 Mn0.2 O 2 , single crystal LiNi 0.5 Co 0.2 Mn 0.3 O 2 , LiNi 0.6 Co 0.1 Mn 0.3 O 2 , LiFePO 4 and their combinations, but the present invention is not limited thereto.

[0034] In some embodiments, the material of the adhesive includes polytetrafluoroethylene (PTFE), rubber (Rubber) or their combinations, but the present invention is not limited thereto.

[0035] In some embodiments, the weight ratio of the second solid electrolyte to the total weight of the positive electrode layer is greater than 20 wt%, the weight ratio of the conductive additive to the total weight of the positive electrode layer is less than 20 wt%, the weight ratio of the active material to the total weight of the positive electrode layer is between 60 wt% and 80 wt%, and the weight ratio of the adhesive to the total weight of the positive electrode layer is between 1 wt% and 5 wt%, but the present invention is not limited thereto. Here, the positive electrode layer may be composed of an active material, a second solid electrolyte, a conductive additive and an adhesive, that is, the sum of the weights of the active material, the second solid electrolyte, the conductive additive and the adhesive is equal to the total weight of the positive electrode layer.

[0036] In some embodiments, the solid electrolyte layer is composed of a single material or at least two materials, and the negative electrode layer is composed of a single metal material or an alloy material, but the present invention is not limited thereto.

[0037] The solid-state lithium battery of the present invention has a relatively compact structure, greater design flexibility, is easier to miniaturize, and has a longer service life through the above-described design. In addition, it will not cause corrosion of the electrodes or accumulation of a solid interface, resulting in shortening of the battery life. The following lists the applicable fields of the solid-state lithium battery of the present invention.

[0038] In some embodiments, when the solid-state lithium battery of the present invention is applied to an electric vehicle, it has a high energy density and fast charge and discharge capabilities, can provide a longer driving range and a shorter charging time for the electric vehicle, and also has higher safety, capable of reducing the risk of battery fire or explosion, but the present invention is not limited thereto.

[0039] In some embodiments, when the solid-state lithium battery of the present invention is applied to mobile electronic devices, it has a high energy density, making it an ideal battery technology for mobile devices such as smartphones, tablets and laptops, and can also achieve a thinner and lighter design, provide a longer battery life and a faster charging speed, but the present invention is not limited thereto.

[0040] In some embodiments, when the solid-state lithium battery of the present invention is applied to wearable devices (such as smart watches, health monitors, and smart glasses), due to its light weight, long battery life, and being a safe and reliable power source, it can meet the requirements of these devices, but the present invention is not limited thereto.

[0041] In some embodiments, when the solid-state lithium battery of the present invention is applied to energy storage systems (such as home energy storage systems, renewable energy storage systems such as solar and wind energy, and energy storage and peak shaving systems of power grids), due to its advantages of high-efficiency energy storage and long cycle life, it helps to improve energy utilization efficiency and the integration of renewable energy, but the present invention is not limited thereto.

[0042] The effects exhibited by the solid-state lithium battery of the present invention will be described in more detail below with reference to examples. In addition, although the following examples are described, without departing from the scope of the present invention, details of the materials used and processes, etc. can be appropriately changed, and the present invention should not be restrictively interpreted by the examples described below. The specific material usage ratios are shown in Table 1, and Example 1 can be regarded as a comparative example, and Examples 2 to 11 can be regarded as embodiments of the present invention.

[0043] Figure 1 is an exploded view of the solid-state lithium battery of the present invention. Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 is the charge-discharge curve diagram of some examples. Figure 10 is the initial charge-discharge curve diagram of some examples. Figure 11 is the discharge capacitance curve diagram of some examples. Figure 12 、 Figure 13 、 Figure 14 、 Figure 15 Discharge capacitance and Coulomb efficiency curve diagrams of some examples. Figure 16 is the AC impedance diagram of some examples. Here, the capacitance in the diagram can be the specific capacity.

[0044] <Example 1>

[0045] The active material (polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 , PC-NCM811), solid electrolyte material (lithium phosphorus sulfur chlorine, LPSCl, Li 6 PS 5(Cl), conductive additives (carbon black, SP) are put into a mortar in a weight ratio of 70 g: 25 g: 5 g and mixed evenly, and then 3 g of binder (polytetrafluoroethylene, PTFE) is added to make a composite positive electrode film. Then, the aforementioned composite positive electrode film is rolled to a thickness of 50 micrometers (μm) and cut into a circle with a diameter of 10 millimeters (mm) as the positive electrode layer. Then, 0.7 g of another solid electrolyte material (lithium phosphorus sulfur chloride, LPSCl, Li 6 PS 5 Cl) powder is put into a mold and cold-pressed at 360 Mpa to make an ingot as the solid electrolyte layer, with a thickness of 450 μm and a diameter of 10 millimeters (mm). Finally, indium metal is cut into a size with a diameter of 10 millimeters (mm) and a thickness of 500 μm as the negative electrode layer, and then as shown in Figure 1 The lower cover 10, aluminum foil 20, positive electrode layer 30, solid electrolyte layer 40, negative electrode layer 50, stainless steel gasket 60, reed 70 and upper cover 80 are sequentially placed into a CR-2032 button-type battery, and the battery is pressed with a pressure of 200 Mpa using a hydraulic press. All of the above processes are carried out in a glove box filled with argon to reduce the probability of the sample being affected by water and oxygen.

[0046] <Example 2>

[0047] Similar to the preparation method of the solid-state lithium battery in Example 1, the difference is that the conductive additive is replaced with graphene (FLG) with 7 - 10 layers.

[0048] <Example 3>

[0049] Similar to the preparation method of the solid-state lithium battery in Example 1, the difference is that the ratio of the active material, solid electrolyte material, conductive additive (carbon black), and conductive additive (graphene) in the composite positive electrode film is 70 g: 25 g: 2.5 g: 2.5 g.

[0050] <Example 4>

[0051] Similar to the preparation method of the solid-state lithium battery in Example 1, the difference is that the conductive additive in the composite positive electrode film is replaced with graphene, and the ratio of the active material, solid electrolyte material, and conductive adhesive is 70 g: 20 g: 10 g.

[0052] <Example 5>

[0053] Similar to the preparation method of the solid-state lithium battery in Example 1, the difference is that the conductive additive in the composite positive electrode film is replaced with graphene, and the ratio of the active material, solid electrolyte material, and conductive adhesive is 65 g: 25 g: 10 g.

[0054] <Example 6>

[0055] Synthesize the solid electrolyte material (LPSCl-1) in advance and set it aside in the following manner. First, put the precursors Li 2 S, P 2 S 5 , and LiCl into a mortar and mix them evenly in a molar ratio of 2.5:0.5:1. The above process is carried out in a glove box filled with argon. Then, load the hand-ground powder into a quartz tube coated with carbon. Use a maintainer and a vacuum system to pump the pressure inside the quartz tube to about 2×10 -2 Torr and then seal the tube. Then, sinter the quartz tube filled with the powder at 550 °C for 5 hours at a heating rate of 5 °C per minute, and then naturally cool it to room temperature and grind it into powder with a mortar.

[0056] Put the active material (polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 , PC-NCM811), the solid electrolyte material (LPSCl-1), the conductive additive (carbon black), and the conductive additive (vapor-grown carbon fiber, VGCF) into a mortar and mix them evenly in a weight ratio of 70 g:30 g:1.5 g:1.5 g. Then add 3 g of the binder (polytetrafluoroethylene, PTFE) to make it into a composite positive electrode film. Next, roll the aforementioned composite positive electrode film to a thickness of 50 μm and cut it into a circle with a diameter of 10 mm as the positive electrode layer. Then, put 0.7 g of another solid electrolyte material (LPSCl-1) powder into a mold and cold-press it at 360 Mpa to make it into an ingot as the solid electrolyte layer, with a thickness of 450 μm and a diameter of 10 millimeters (mm). Finally, cut indium metal into a size with a diameter of 10 mm and a thickness of 500 μm as the negative electrode layer. Then, as shown in Figure 1 , put the lower cover 10, the aluminum foil 20, the positive electrode layer 30, the solid electrolyte layer 40, the negative electrode layer 50, the stainless steel gasket 60, the reed 70, and the upper cover 80 into a CR-2032 button-type battery in sequence, and use a hydraulic press to press the battery at a pressure of 200 Mpa. The above processes are all carried out in a glove box filled with argon to reduce the probability of the sample being affected by water and oxygen.

[0057] <Example 7>

[0058] Synthesize the solid electrolyte material (LPSClO-0.1) including the oxygen-doped material in advance and set it aside in the following manner. First, put the precursors Li 2 S, P 2 S 5 , LiCl, Li 2O is put into a mortar and mixed evenly at a molar ratio of 2.4:0.5:1:0.1. The above process is carried out in a glove box filled with argon. Then, the hand-ground powder is loaded into a quartz tube coated with carbon, and the pressure in the quartz tube is pumped to about 2×10 -2 Torr using a retainer and a vacuum system, and then the tube is sealed. Then, the quartz tube containing the powder is subjected to high-temperature sintering at 550 °C for 5 hours with a heating rate of 5 °C per minute, and then naturally cooled to room temperature and ground into powder using a mortar.

[0059] The active material (polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 , PC-NCM811), solid electrolyte material (LPSClO-0.1), conductive additive (carbon black), and conductive additive (vapor-grown carbon fiber) are put into a mortar and mixed evenly at a weight ratio of 70 g:30 g:1.5 g:1.5 g. Then, 3 g of adhesive (polytetrafluoroethylene, PTFE) is added to make a composite cathode film. Next, the aforementioned composite cathode film is rolled to a thickness of 50 μm and cut into a circle with a diameter of 10 mm as the cathode layer. Then, 0.7 g of another solid electrolyte material (LPSClO-0.1) powder is put into a mold and cold-pressed at 360 Mpa to make an ingot as the solid electrolyte layer with a thickness of 450 μm and a diameter of 10 millimeters (mm). Finally, indium metal is cut into a size with a diameter of 10 mm and a thickness of 500 μm as the anode layer, and then as shown in Figure 1 , the lower cover 10, aluminum foil 20, cathode layer 30, solid electrolyte layer 40, anode layer 50, stainless steel gasket 60, spring piece 70, and upper cover 80 are sequentially placed into a CR-2032 button-type battery, and the battery is pressed at a pressure of 200 Mpa using a hydraulic press. The above processes are all carried out in a glove box filled with argon to reduce the probability of the sample being affected by water and oxygen.

[0060] <Example 8>

[0061] The active material (polycrystalline LiNi 0.8 Co 0.1 Mn 0.1 O 2 , PC-NCM811), solid electrolyte material (lithium indium chloride material, Li 3 InCl 6) and a conductive additive (vapor-phase carbon fiber) are put into a mortar and mixed evenly at a weight ratio of 70 g:30 g:3 g, and then 3 g of an adhesive (polytetrafluoroethylene, PTFE) is added to make a composite positive electrode film. Next, the aforementioned composite positive electrode film is rolled to a thickness of 50 μm and cut into a circle with a diameter of 10 mm as the positive electrode layer. Then, 0.5 g of another solid electrolyte material (lithium indium chloride material, Li 3 InCl 6 ) powder is put into a mold and cold-pressed at 360 Mpa to make an ingot, and then 0.7 g of another solid electrolyte material (lithium phosphorus sulfur chloride, LPSCl, Li 6 PS 5 Cl) powder is put into a mold and cold-pressed at 360 Mpa to make a double-layer ingot as the solid electrolyte layer, with a thickness of 450 μm and a diameter of 10 millimeters (mm). Finally, lithium metal is cut into a size with a diameter of 10 mm and a thickness of 500 μm with a pill cutter as the negative electrode layer, and then as shown in Figure 1 , the lower cover 10, aluminum foil 20, positive electrode layer 30, solid electrolyte layer 40, negative electrode layer 50, stainless steel gasket 60, reed 70 and upper cover 80 are sequentially placed into a CR-2032 button-type battery, and the battery is pressed with a hydraulic press at a pressure of 200 Mpa, and the above processes are all carried out in a glove box filled with argon to reduce the probability of the sample being affected by water and oxygen.

[0062] <Example 9>

[0063] Similar to the preparation method of the solid-state lithium battery in Example 8, the difference is that the material of the negative electrode layer is replaced with indium.

[0064] <Example 10>

[0065] Similar to the preparation method of the solid-state lithium battery in Example 8, the difference is that the material of the negative electrode layer is replaced with a lithium indium alloy, where indium metal is on top and lithium metal is at the bottom, and they are stacked and cold-pressed at 20 Mpa to make a lithium indium alloy, and the weight ratio of lithium metal to indium metal is 2:55.

[0066] <Example 11>

[0067] The active material (single crystal LiNi 0.6 C 0.1 Mn 0.3 O 2 , SC-NCM613), solid electrolyte material (lithium indium chloride material, Li 3 InCl 6) The conductive additive (carbon black) and the conductive additive (vapor-grown carbon fiber) are put into a mortar and mixed evenly at a weight ratio of 70 g:30 g:1.5 g:1.5 g. Then, 3 g of the binder (polytetrafluoroethylene, PTFE) is added to form a composite positive electrode film. Next, the aforementioned composite positive electrode film is rolled to a thickness of 50 μm and cut into a circle with a diameter of 10 mm as the positive electrode layer. Then, 0.5 g of the solid electrolyte material (lithium indium chloride material, Li3InCl6) powder is put into a mold and cold-pressed at 360 Mpa to form an ingot. Then, 0.7 g of another solid electrolyte material (LPSClO-0.1 prepared in Example 7) powder is put into a mold and cold-pressed at 360 Mpa to form a double-layer ingot as the solid electrolyte layer, with a thickness of 450 μm and a diameter of 10 millimeters (mm). Finally, indium metal and lithium metal are cut into a size with a diameter of 10 mm and a thickness of 550 μm with a pill cutter. The indium metal is on top and the lithium metal is at the bottom, and they are stacked and cold-pressed at 20 Mpa to form a lithium indium alloy, with a weight ratio of lithium metal to indium metal of 2:55, as the negative electrode layer. Then, as shown in Figure 1 , the lower cover 10, the aluminum foil 20, the positive electrode layer 30, the solid electrolyte layer 40, the negative electrode layer 50, the stainless steel gasket 60, the reed 70, and the upper cover 80 are sequentially placed into a CR-2032 button-type battery, and the battery is pressed with a pressure of 200 Mpa using a hydraulic press. All the above processes are carried out in a glove box filled with argon to reduce the probability of the sample being affected by water and oxygen.

[0068] Table 1

[0069]

[0070]

[0071] Each example is evaluated according to the following method.

[0072] Figure 2 、 Figure 3 、 Figure 4 、 Figure 5 、 Figure 6 、 Figure 7 、 Figure 8 、 Figure 9 The charge-discharge curves of are corresponding to Example 1, Example 2, Example 3, Example 4, Example 5, Example 6, Example 7, and Example 11 respectively, and their operating conditions are cycling 3 times at 0.05C and then cycling 30 or 50 times at 0.1C, voltage range of 2.2V to 3.7V, and temperature of 55°C.

[0073] Figure 10 The initial charge-discharge curves of are corresponding to Example 1, Example 2, Example 3, and Example 5, and their operating conditions are cycling at 0.05C, voltage range of 2.2V to 3.7V, and temperature of 55°C.

[0074] Figure 12 They are the discharge capacitance and Coulomb efficiency curves of Examples 1, 2, 3, and 4, and their operating conditions are cycling 3 times at 0.05C and then 30 times at 0.1C, with a voltage range of 2.2V to 3.7V and a temperature of 55°C.

[0075] Figure 13 They are the discharge capacitance and Coulomb efficiency curves of Examples 6 and 7, and their operating conditions are cycling 3 times at 0.05C and then 50 times at 0.1C, with a voltage range of 2.2V to 3.7V and a temperature of 55°C.

[0076] Figure 14 They are the discharge capacitance and Coulomb efficiency curves of Examples 8, 9, and 10, and their operating conditions are cycling 3 times at 0.05C and then 30 times at 0.1C, with a voltage range of 2.2V to 3.7V and a temperature of 55°C.

[0077] Figure 15 They are the discharge capacitance and Coulomb efficiency curves of Example 11, and their operating conditions are cycling 30 times at 0.1C, with a voltage range of 2.2V to 3.7V and a temperature of 55°C.

[0078] Figure 16 For the AC impedance diagram, its operating conditions are that the AC impedance frequency is set in the range of 100mHz to 7MHz, and the amplitude is 10mV.

[0079] In addition, the electrical test results of each embodiment are shown in Table 2.

[0080] Table 2

[0081]

[0082] From the above Figures 2 to 16 and the results in Table 2, it can be seen that when the materials of the positive electrode layer of the solid-state lithium battery in the embodiments of the present invention (Examples 2 to 11) include oxygen-doped materials, graphene materials, or lithium indium chloride materials, they have good electrochemical stability and can also maintain similar electrical performance compared with the comparative example (Example 1). For example, in some examples, at a current density of 0.1C, the first-cycle reversible capacitance can reach about 180 mAh / g, and after 50 charge-discharge cycles, about 80% of the capacitance retention rate is still retained. In addition, when the solid electrolyte layer of the solid-state lithium battery in the embodiments of the present invention uses oxygen-doped materials (Examples 7 and 11) and / or the negative electrode layer uses lithium indium alloy, it also has good electrochemical stability and maintains similar electrical performance compared with the comparative example (Example 1).

[0083] In summary, the solid-state lithium battery of the present invention, at least through the design of the positive electrode layer, introduces materials of a second solid electrolyte with relatively low reactivity and / or materials of a conductive additive, so that it has good electrochemical stability while maintaining electrical performance.

[0084] Finally, it should be noted that: the above embodiments are only used to illustrate the technical solutions of the present invention, rather than to limit it; although the present invention has been described in detail with reference to the foregoing embodiments, those of ordinary skill in the art should understand that: they can still modify the technical solutions recorded in the foregoing embodiments, or perform equivalent replacements on some or all of the technical features; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the scope of the technical solutions of the embodiments of the present invention.

Claims

1. A solid-state lithium battery, characterized in that: include: Negative electrode layer; a solid electrolyte layer including a first solid electrolyte; and The positive electrode layer includes an active material, a second solid electrolyte, a conductive additive and an adhesive, wherein: The material of the second solid electrolyte includes oxygen-doped sulfide or lithium indium chloride; and / or The material of the conductive additive includes graphene.

2. The solid-state lithium battery according to claim 1, characterized in that: The oxygen-doped sulfide includes Li6PS 5- x C1O x 、Li6PS 5-x B O x 、Li6PS 5-x IO x and their combinations, x=0~1.

3. The solid-state lithium battery according to claim 1, characterized in that: The weight ratio of the second solid electrolyte to the total weight of the positive electrode layer is greater than 20 wt %.

4. The solid-state lithium battery according to claim 1, characterized in that: The weight ratio of the conductive additive relative to the total weight of the positive electrode layer is less than 20 wt %.

5. The solid-state lithium battery according to claim 1, characterized in that: The weight ratio of the active material to the total weight of the positive electrode layer is between 60wt% and 80wt%.

6. The solid-state lithium battery according to claim 1, characterized in that: The weight ratio of the adhesive to the total weight of the positive electrode layer is between 1 wt % and 5 wt %.

7. The solid-state lithium battery according to claim 1, characterized in that: The number of layers of the graphene material is between 3 and 20.

8. The solid-state lithium battery according to claim 1, characterized in that: The first solid electrolyte and the second solid electrolyte are made of the same material.

9. The solid-state lithium battery according to claim 1, characterized in that: The material of the conductive additive further includes carbon black, gas-phase carbon fiber or carbon nanotube.

10. The solid-state lithium battery according to claim 1, characterized in that: The material of the negative electrode layer includes lithium, indium or a combination thereof.

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