An all-solid-state thin film battery and a method of manufacturing the same

Abstract

The application relates to the field of batteries, in particular to a full solid-state thin film battery and a preparation method thereof. The full solid-state thin film battery comprises a positive electrode current collector layer, a positive electrode layer, a solid electrolyte layer, a negative electrode layer and a negative electrode current collector layer; the thickness of the positive electrode layer and the solid electrolyte layer is 10 nm-50 mu m; the positive electrode layer is composed of a material containing a sulfur element and having a charge storage capacity; when the positive electrode layer is composed of a material containing a sulfur element and a metal element and having a charge storage capacity, the thickness of the negative electrode layer is 0 nm-50 mu m; when the positive electrode layer is composed of a material containing a sulfur element and having a charge storage capacity, the thickness of the negative electrode layer is 10 nm-50 mu m; the thickness of the positive electrode current collector layer is 10 nm-100 mu m; and the thickness of the negative electrode current collector layer is 0 nm-100 mu m. The application can effectively reduce the cost of the battery, improve the electric capacity of the battery, and make the battery large-area and mass-produced.

Description

TECHNICAL FIELD

[0001] The present application relates to the field of batteries, more particularly, it relates to a full solid thin film battery and a preparation method thereof. BACKGROUND

[0002] There are several common batteries on the market:

[0003] 1. Liquid battery, mainly liquid lithium battery, using liquid electrolyte, has the advantages of high energy density, long service life, etc., but poor safety performance, easy to catch fire and cause accidents.

[0004] 2. Full solid-state battery, a battery that uses full solid-state electrolyte and does not contain liquid components, has the advantages of non-flammable and non-explosive, high energy density, etc., but the grain boundaries between the structures have large impedance, and the electronic migration is poor, resulting in poor charge and discharge performance and poor rate performance.

[0005] 3. Thin film battery, the positive and negative electrode materials are the same as those of liquid battery and full solid-state battery, thin film battery is usually in micrometer or nanometer level, has the advantages of light weight, high energy density, good safety performance, etc., but its manufacturing process is complex, it needs to be annealed multiple times, which limits its large-area and mass production, and the capacity is small.

[0006] 4. Na-S battery, using sulfur, sodium and other materials as positive and negative electrode materials, has the advantage of low cost, but its working temperature needs to be controlled at 300-350℃, which is not suitable for rapid start charging and discharging, so it is only suitable for stationary energy storage field, and is prone to thermal runaway and other problems.

[0007] The closest prior art to the present application is a thin film battery, and the main defects of the existing thin film battery are:

[0008] (1) The main material is lithium or lithium-containing compounds, but the lithium element resource is limited and the cost is high.

[0009] (2) The capacity is low, mainly limited by the thin film preparation technology. In the preparation process, at least one annealing is needed for each plating film, and annealing usually needs to be carried out at a high temperature, which makes it impossible to prepare batteries in large area and mass production. The prepared batteries are mostly like fingernail covers, so the low capacity limits the application of thin film batteries. SUMMARY

[0010] In order to reduce the cost of the battery and improve the capacity of the battery, so that it can be prepared in large area and mass production, the present application provides a full solid thin film battery and a preparation method thereof.

[0011] In the first aspect, the present application provides a full solid thin film battery, which adopts the following technical scheme:

[0012] A kind of all-solid-state thin film battery, comprising positive electrode current collector layer, positive electrode layer, solid electrolyte layer, negative electrode layer, negative electrode current collector layer;

[0013] Positive electrode layer, solid electrolyte layer, negative electrode current collector layer are sequentially connected;

[0014] Positive electrode current collector layer is arranged at the side of positive electrode layer away from solid electrolyte layer, negative electrode current collector layer is arranged at the side of negative electrode layer away from solid electrolyte layer,

[0015] Or, positive electrode current collector layer is arranged at the side of positive electrode layer, solid electrolyte layer, negative electrode current collector layer, negative electrode current collector layer is arranged at the other side of positive electrode layer, solid electrolyte layer, negative electrode current collector layer;

[0016] The thickness of positive electrode layer is 10nm-50 μm, and the positive electrode layer is composed of material containing sulfur element and having storage and discharge capacity;

[0017] The thickness of solid electrolyte layer is 10nm-50 μm;

[0018] When the positive electrode layer is composed of material containing sulfur element and metal element and having storage and discharge capacity, the thickness of negative electrode layer is 0nm-50 μm;When the positive electrode layer is composed of material containing sulfur element and having storage and discharge capacity, the thickness of negative electrode layer is 10nm-50 μm;

[0019] The thickness of positive electrode current collector layer is 10nm-100 μm;

[0020] When the negative electrode layer is composed of material not having conductive capacity, the thickness of negative electrode current collector layer is 10nm-100 μm;When the negative electrode layer is composed of material having conductive capacity, the thickness of negative electrode current collector layer is 0nm-100 μm.

[0021] Preferably, the weight content of material having storage and discharge capacity in the positive electrode layer is 20%-100%. Preferably, it is 50%-98%, more preferably, it is 70%-97%.

[0022] Preferably, the material of the positive electrode layer is one of sodium sulfide, sulfur, material integrated with the aforementioned sodium sulfide or sulfur and containing conductive agent, composite compound containing the aforementioned element, sodium battery positive electrode material containing sodium element.

[0023] Preferably, the weight content of material having storage and discharge capacity in the negative electrode layer is 50%-100%. Preferably, it is 80%-98%, more preferably, it is 90%-97%.

[0024] Preferably, the material of the negative electrode layer is one of tin, sodium-tin alloy, carbon sodium storage material, composite material containing sodium storage functional material, structure or material integrated with negative electrode current collector and having sodium storage function.

[0025] Preferably, the thickness of the positive electrode layer is 40 nm-2000 nm.

[0026] Preferably, the positive electrode layer is a dense thin film.

[0027] Preferably, the thickness of the negative electrode layer is 40 nm-200 nm.

[0028] The core raw material of the present application is a raw material containing S and Na elements, which is widely available and low in cost, and can effectively reduce the cost of the battery.

[0029] In a second aspect, the present application provides a preparation method of a full solid-state thin film battery, which adopts the following technical scheme:

[0030] A preparation method of a full solid-state thin film battery, the positive electrode layer, the solid-state electrolyte layer and the negative electrode layer are plated by vacuum plating or magnetron sputtering.

[0031] Preferably, the positive electrode layer, the solid-state electrolyte layer and the negative electrode layer of the full solid-state thin film battery can be plated by vacuum plating in any one or more layers, and the remaining layers are plated by magnetron sputtering.

[0032] Preferably, when the full solid-state thin film battery is plated by vacuum evaporation, the preparation method comprises the following steps:

[0033] Step 1: set the positive electrode current collector layer as the thin film deposition substrate, and vacuumize to 1.0×10 -3 Pa or below;

[0034] Step 2: adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated positive electrode layer material deposit on the thin film deposition substrate, until the cumulative deposition thickness reaches the target thickness, to form the positive electrode layer;

[0035] Step 3: adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated solid-state electrolyte layer deposit on the positive electrode layer, until the cumulative deposition thickness reaches the target thickness, to form the solid-state electrolyte layer;

[0036] Step 4: adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated negative electrode layer deposit on the solid-state electrolyte layer material, until the cumulative deposition thickness reaches the target thickness, to form the single layer of the negative electrode layer;

[0037] Step 5: adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated negative electrode current collector material deposit on the negative electrode layer material, until the cumulative deposition thickness reaches the target thickness, to form the negative electrode current collector layer.

[0038] A full solid-state thin film battery is obtained.

[0039] Preferably, the all-solid-state thin film battery is coated by magnetron sputtering, and the preparation method comprises the following steps:

[0040] Step 1: set the positive current collector layer as the thin film deposition substrate, and vacuumize to 1.0×10 -3 Pa or below, and then introduce inert gas;

[0041] Step 2: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, deposit the sputtered positive layer material on the thin film deposition substrate, until the cumulative deposition thickness reaches the target thickness, to form the positive layer;

[0042] Step 3: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, deposit the sputtered solid electrolyte layer on the positive layer material, until the cumulative deposition thickness reaches the target thickness, to form the solid electrolyte layer;

[0043] Step 4: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, deposit the sputtered negative layer on the solid electrolyte layer material, until the cumulative deposition thickness reaches the target thickness, to form the negative layer;

[0044] Step 5: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, deposit the sputtered negative current collector material on the negative layer material, until the cumulative deposition thickness reaches the target thickness, to form the negative current collector layer;

[0045] to obtain the all-solid-state thin film battery.

[0046] Preferably, the positive layer and the negative layer of the all-solid-state thin film battery are coated by vacuum coating, and the solid electrolyte layer is coated by magnetron sputtering, and the preparation method comprises the following steps:

[0047] Step 1: set the positive current collector layer as the thin film deposition substrate, and vacuumize to 1.0×10 -3 Pa or below;

[0048] Step 2: adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, deposit the evaporated positive layer material on the thin film deposition substrate, until the cumulative deposition thickness reaches the target thickness, to form the positive layer;

[0049] Step 3: introduce inert gas, and adjust the spraying power, when the film thickness change rate reaches 0.1-0.5 nm / s, deposit the sprayed solid electrolyte layer on the positive layer material, until the cumulative deposition thickness reaches the target thickness, to form the solid electrolyte layer;

[0050] Step 4: stop the inert gas, adjust the evaporation current, when the film thickness changes to 0.1-0.5 nm / s, make the negative electrode layer deposited on the solid electrolyte layer material, to the cumulative deposition thickness reaches the target thickness, form a negative electrode layer; the whole is a full solid-state thin film battery.

[0051] Due to the high theoretical energy density, low cost and abundance of sodium and sulfur, room temperature liquid sodium-sulfur (RT Na-S) battery is studied as a promising energy storage system. However, the inherent electronic insulating property of S, the dissolution and shuttling of intermediate sodium polysulfides, and especially the slow conversion kinetics, limit the commercial application of liquid RT Na-S batteries. And the volatility of raw materials containing S elements in high vacuum and the inherent slow kinetics hinder researchers from integrating them into full solid-state thin film batteries empirically.

[0052] And the application overcomes the above problems by selecting specific raw materials and special preparation methods, and does not need to be annealed for many times, nor needs to be prepared at a high temperature, so that the battery can be mass-produced in large area, and the thin film battery is endowed with high capacity.

[0053] In summary, the application has the following beneficial effects:

[0054] 1. The battery provided by the application has high energy density, which can be more than 500 Wh / kg.

[0055] 2. The battery provided by the application has high rate performance, which can be more than 10C.

[0056] 3. The battery provided by the application has long service life, which is more than 10,000 cycles.

[0057] 4. The battery material provided by the application is cheap and low in cost, which is as low as 0.2 yuan / Wh.

[0058] 5. The battery provided by the application is safe and completely non-flammable.

[0059] 6. The battery provided by the application has excellent high and low temperature resistance and can be used at-40℃-80℃.

[0060] 7. The battery provided by the application has a simple manufacturing process, which can be completed within 2 days.

[0061] 8. The battery provided by the application can realize internal series and parallel connection, can withstand large current and high voltage, and can directly form a pack across the module without redundant components such as condensate water explosion-proof system. BRIEF DESCRIPTION OF DRAWINGS

[0062] Figure 1 is a structural schematic diagram of the full solid-state thin film battery of Example 1.

[0063] Figure 2 is the sample after vacuum plating of Example 1 (containing 4 Figure 1 full solid thin film battery of the structure).

[0064] Figure 3 is the first cycle charge-discharge curve of the full solid thin film battery of Example 1 in charge-discharge test. DETAILED DESCRIPTION

[0065] The application is further described in detail below in conjunction with the accompanying drawings and examples.

[0066] The raw materials used in the following examples and comparative examples are all commercially available products. EXAMPLE

[0067] A full solid thin film battery comprises single or multiple layers of: a positive current collector layer, a positive electrode layer, a solid electrolyte layer, a negative electrode layer, and a negative current collector layer.

[0068] 1. Positive current collector layer:

[0069] The positive current collector layer can be any one or mixed combination of copper foil, aluminum foil, stainless steel foil, composite copper foil, composite aluminum foil, metal thin film formed by plating, composite conductive thin film, etc.

[0070] The thickness thereof can be any one of 10 nm, 100 nm, 1 μm, 5 μm, 10 μm, 50 μm, 100 μm, etc.

[0071] 2. Positive electrode layer:

[0072] The positive electrode layer can be any one or mixed combination of sodium sulfide, sulfur, lithium sulfide, iron sulfide, zinc sulfide, copper sulfide, polymeric sulfur-containing compounds, etc.

[0073] When it is sodium sulfide, it can be sodium sulfide, sodium tetrasulfide, sodium polysulfide.

[0074] The thickness thereof can be any one of 10 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 5 μm, 10 μm, 50 μm, etc.

[0075] 3. Solid electrolyte layer:

[0076] The solid electrolyte layer can be any one or mixed combination of sodium phosphate, Na3La(PO4)2, Na-β-Al2O3, Na 1+x Zr2Si x P 3-x O 12 sodium superionic conductor (NASICON) of the Na3V2(PO4)3

[0077] The thickness can be any of 10 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 5 μm, 10 μm, 50 μm, etc.

[0078] 4. The negative electrode layer:

[0079] (1) When the positive electrode layer is composed of a material containing sulfur element and metal element and having the ability to store electricity, the thickness of the negative electrode layer can be any of 0 nm, 1 nm, 5 nm, 10 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 5 μm, 10 μm, 50 μm, etc.

[0080] The material containing sulfur element and metal element and having the ability to store electricity can be sodium sulfide, lithium sulfide, potassium sulfide, sodium polysulfide.

[0081] (2) When the positive electrode layer is composed of a material containing sulfur element and having the ability to store electricity, the thickness of the negative electrode layer can be any of 10 nm, 100 nm, 200 nm, 300 nm, 400 nm, 500 nm, 600 nm, 700 nm, 800 nm, 900 nm, 1 μm, 5 μm, 10 μm, 50 μm, etc.

[0082] The material containing sulfur element and having the ability to store electricity can be sulfur, polymeric sulfur organic compound, sodium sulfide, lithium sulfide, potassium sulfide, sodium polysulfide.

[0083] 5. The negative electrode current collector layer:

[0084] The negative electrode current collector layer can use any one or a mixture of sodium, tin, sodium-tin alloy, copper, aluminum, etc.

[0085] The thickness can be any of 10 nm, 100 nm, 1 μm, 5 μm, 10 μm, 50 μm, 100 μm, etc.

[0086] Example 1

[0087] Reference Figure 1 A kind of all-solid-state thin film battery, the thickness of positive electrode layer Na2S is 500 nm, the thickness of solid electrolyte layer Na3PO4 is 300 nm, the thickness of negative electrode layer Sn is 100 nm. The plating film process of Na2S film layer, Na3PO4 film layer, Sn film layer adopts magnetron sputtering method.

[0088] Specifically includes the following steps:

[0089] Step 1: using Shenyang Kejing Automation Equipment Co., Ltd. production of three target magnetron sputtering coating device (model VTC-600-3HD). In three target head respectively installed Na2S target piece (diameter 50mm, thickness 3mm), Na3PO4 target piece (diameter 50mm, thickness 3mm), Sn target piece (diameter 50mm, thickness 3mm), set up on the sample table copper foil (diameter 100mm, thickness 20μm) as the film deposition substrate, set up mask mold to prepare the positive electrode layer / solid-state electrolyte layer / negative electrode layer circuit does not short sandwich structure. Sample table set rotation 10 turns / min, vacuum to 1.0×10 -3 Pa below, adjust the device. The flow rate of argon gas is 15ml / min, and the vacuum value is controlled at about 4Pa.

[0090] Step 2: slowly adjust the radio frequency power of sodium sulfide target to 100W, when the film thickness instrument shows that the film thickness change rate reaches 0.1nm / s, open the sample table shutter, make the sputtered sodium sulfide deposit on the copper foil of the sample table, when the cumulative deposition thickness reaches 500nm, close the sample table shutter, reduce the radio frequency power of sodium sulfide target to zero. At this time, the positive electrode layer is formed.

[0091] Step 3: while controlling the vacuum value at about 4.0Pa, nitrogen gas is introduced at a flow rate of 15ml / min, and the radio frequency power of sodium phosphate target is slowly adjusted to 100W. When the film thickness instrument shows that the film thickness change rate reaches 0.1nm / s, open the sample table shutter, make the sputtered sodium phosphate continue to deposit on the copper foil of the sample table, when the cumulative deposition thickness reaches 300nm, close the sample table shutter, reduce the radio frequency power of sodium phosphate target to zero. At this time, the solid-state electrolyte layer covering the positive electrode layer is formed.

[0092] Step 4: turn off the nitrogen. Slowly adjust the radio frequency power of tin target to 50W, when the film thickness instrument shows that the film thickness change rate reaches 0.1nm / s, open the sample table shutter, make the sputtered tin continue to deposit on the copper foil of the sample table, when the cumulative deposition thickness reaches 100nm, close the sample table shutter, reduce the radio frequency power of tin target to zero. At this time, the negative electrode layer located on the solid-state electrolyte layer is formed.

[0093] Step 5: cut the copper foil after vacuum coating described above (diameter 100mm, thickness 20μm) Figure 2 , containing 4 Figure 1 structure of all-solid-state thin film battery) is cut, and the sample structure diagram obtained after cutting is as Figure 1 (diameter of positive electrode film layer and negative electrode film layer is 1cm 2 ).

[0094] The copper foil is used as the positive electrode tab and the tin layer is used as the negative electrode tab. The aluminum-plastic film small soft package battery, i.e., the all-solid-state thin film battery, is prepared in an argon atmosphere glove box (water content is less than 0.1 ppm, oxygen content is less than 0.1 ppm).

[0095] Performance detection:

[0096] The thickness of each deposited material is obtained by a film thickness meter. The weight of sodium sulfide in the battery is 9.3 ug, the weight of sodium phosphate is 48.6 ug, and the weight of tin is 72.8 ug, which is obtained by theoretical calculation.

[0097] The small soft package battery is subjected to charge and discharge test by using a battery charge and discharge system (Shenglan battery tester SLAN-CT2001A).

[0098] The first circle charging current is 0.5 uA, and the discharging current is 0.5 uA. The test results show that the first circle charging capacity of the positive electrode material of the battery is 460 mAh / g, the discharging capacity is 391 mAh / g, and the coulomb efficiency is 85%. The charge and discharge curve is as shown in Figure 3 .

[0099] The second circle charging current is 1 uA, and the discharging current is 1 uA. The second circle discharging capacity is 421 mAh / g, and the coulomb efficiency is 96%

[0100] The third circle charging current is 1 uA, and the discharging current is 2.5 uA. The third circle discharging capacity is 378 mAh / g, and the coulomb efficiency is 95%.

[0101] The fourth circle charging current is 1 uA, and the discharging current is 1 uA. Under the same charge and discharge conditions, the 103rd circle charging capacity after 100 times of discharging is 398 mAh / g, the discharging capacity is 390 mAh / g, and the coulomb efficiency is 98%.

[0102] The maintenance rate of the discharging capacity of the third circle compared with the discharging capacity of the second circle is 90%, indicating that the discharging rate performance is good after the discharging current is increased by 2.5 times.

[0103] The maintenance rate of the discharging capacity of the 103rd circle compared with the discharging capacity of the fourth circle is 92%, indicating that the cycle performance is good after 100 times of cycle charge and discharge.

[0104] The total weight of the deposited material in the battery and the discharging capacity and average discharging voltage of the second circle are used for calculation, and the energy density of the battery is 491 Wh / kg.

[0105] Example 2

[0106] An all-solid-state thin film battery includes a positive electrode current collector, a positive electrode layer, a solid-state electrolyte layer, and a negative electrode layer.

[0107] The material of the positive electrode layer is Na2S, and the thickness is 1000 nm, which is a dense film; the material of the solid-state electrolyte layer is Na3PO4, and the thickness is 300 nm; the material of the negative electrode layer is Sn, and the thickness is 300 nm. The film coating process of the Na2S film layer, the Na3PO4 film layer and the Sn film layer adopts an evaporation film coating method.

[0108] The method comprises the following steps:

[0109] Step 1: An evaporation vacuum film coater (model GSL-1800X-ZF4) produced by Shenyang Kejing Automation Equipment Company is used, sodium sulfide powder, sodium phosphate powder and tin powder are respectively placed on three tungsten boats as evaporation source target materials, a copper foil (diameter 100 mm, thickness 20 μm) is set on a sample table as a film deposition substrate, and a mask mold is set to prepare a sandwich structure of the positive electrode layer / solid-state electrolyte layer / negative electrode layer without short circuit of the circuit. The sample table is set to rotate at 10 revolutions per minute, and vacuum is extracted to 1.0*10 -3 Pa or below.

[0110] Step 2: The evaporation current of the sodium sulfide evaporation target material is slowly adjusted to 50 A, and when the film thickness change speed displayed by the film thickness instrument reaches 0.2 nm / s, the sample table shutter is opened, so that the evaporated sodium sulfide is deposited on the copper foil of the sample table, and when the cumulative deposition thickness reaches 500 nm, the sample table shutter is closed, and the evaporation current of the sodium sulfide target material is reduced to zero. At this time, the positive electrode layer is formed.

[0111] Step 3: The evaporation current of the sodium phosphate evaporation target material is slowly adjusted to 20 A, and when the film thickness change speed displayed by the film thickness instrument reaches 0.2 nm / s, the sample table shutter is opened, so that the evaporated sodium phosphate continues to be deposited on the copper foil of the sample table, and when the cumulative deposition thickness reaches 300 nm, the sample table shutter is closed, and the evaporation current of the sodium phosphate target material is reduced to zero. At this time, the solid-state electrolyte layer covering the positive electrode layer is formed.

[0112] Step 4: The evaporation current of the tin evaporation target material is slowly adjusted to 80 A, and when the film thickness change speed displayed by the film thickness instrument reaches 0.2 nm / s, the sample table shutter is opened, so that the evaporated tin continues to be deposited on the copper foil of the sample table, and when the cumulative deposition thickness reaches 100 nm, the sample table shutter is closed, and the evaporation current of the tin target material is reduced to zero. At this time, the negative electrode layer on the solid-state electrolyte layer is formed.

[0113] Step 5: The copper foil on which the vacuum film coating in step 4 is completed is cut.

[0114] The copper foil is used as the positive electrode current collector layer to lead out the positive electrode tab, and the tin layer is used as the negative electrode current collector layer to lead out the negative electrode tab. An aluminum-plastic film small soft-pack battery, i.e., a full-solid thin film battery, is prepared in an argon atmosphere glove box (water content is less than 0.1 ppm, and oxygen content is less than 0.1 ppm).

[0115] Performance detection:

[0116] The thickness of the film layer is obtained by a film thickness meter. The weight of sodium sulfide in the battery is 18.6 ug, the weight of sodium phosphate is 48.6 ug, and the weight of tin is 218 ug, which are obtained by theoretical calculation.

[0117] The small soft-pack battery is subjected to charge-discharge test by using a battery charge-discharge system (Shenglan battery tester SLAN-CT2001A).

[0118] The first cycle charge current is 0.5 uA, and the discharge current is 0.5 uA. The test results show that the first cycle charge capacity of the battery is 345 mAh / g, the discharge capacity is 283 mAh / g, and the coulombic efficiency is 82%.

[0119] The second cycle charge current is 1 uA, and the discharge current is 1 uA. The second cycle discharge capacity is 313 mAh / g, and the coulombic efficiency is 95%.

[0120] The third cycle charge current is 1 uA, and the discharge current is 2.5 uA. The third cycle charge capacity is 466 mAh / g, the discharge capacity is 278 mAh / g, and the coulombic efficiency is 93%.

[0121] The fourth cycle charge current is 1 uA, and the discharge current is 1 uA. Under the same charge-discharge conditions, the 103th cycle charge capacity after 100 times of discharge is 295 mAh / g, the discharge capacity is 298 mAh / g, and the coulombic efficiency is 99%.

[0122] The discharge capacity maintenance rate of the third cycle discharge capacity compared with the second cycle discharge capacity is 88%, indicating that the discharge rate performance is good after the discharge current is increased by 2.5 times.

[0123] The discharge capacity maintenance rate of the 103th cycle discharge capacity compared with the fourth cycle discharge capacity is 94%, indicating that the cycle performance is good after 100 times of cycle charge-discharge.

[0124] The energy density of the battery is 348 Wh / kg, which is obtained by using the weight of the deposited material in the battery and the second cycle discharge capacity and average discharge voltage for calculation.

[0125] Example 3

[0126] A kind of all-solid-state thin film battery, Na2S thickness is 1500 nm, Na3PO4 Thickness is 500 nm, Sn thickness is 300 nm, Na3PO4 Layer is made using the magnetron sputtering coating method of example 1, Na2S layer and Sn layer are made using the evaporation coating method of example 2, other operating methods are the same with example 1, here is not described.

[0127] Performance detection:

[0128] The film thickness is obtained by film thickness gauge, and the weight of sodium sulfide in the battery is 27.9 ug, the weight of sodium phosphate is 8.1 ug, and the weight of tin is 218 ug by theoretical calculation.

[0129] The small soft package battery is charged and discharged using battery charging and discharging system (Shenglan battery tester SLAN-CT2001A).

[0130] The first circle charging current is 0.5 uA, and the discharging current is 0.5 uA. The test results show that the first circle charging capacity of the battery is 414 mAh / g, the discharging capacity is 352 mAh / g, and the coulomb efficiency is 85%.

[0131] The second circle charging current is 1 uA, and the discharging current is 1 uA. The second circle charging capacity is 395 mAh / g, the discharging capacity is 379 mAh / g, and the coulomb efficiency is 96%.

[0132] The third circle charging current is 1 uA, and the discharging current is 2.5 uA. The third circle discharging capacity is 340 mAh / g, and the coulomb efficiency is 95%.

[0133] The fourth circle charging current is 1 uA, and the discharging current is 1 uA. Similarly, the electric capacity of the 103rd circle after repeating discharging 100 times under the same charging and discharging conditions is 358 mAh / g, the discharging capacity is 351 mAh / g, and the coulomb efficiency is 98%.

[0134] The discharging capacity of the third circle compared with the discharging capacity of the second circle, the maintenance rate of discharging capacity is 89%, which shows that the discharging rate performance is good after the discharging current is increased by 2.5 times.

[0135] The discharging capacity of the 103rd circle compared with the discharging capacity of the fourth circle, the maintenance rate of discharging capacity is 92%, which shows that the cycle performance is good after 100 times of cycle charging and discharging.

[0136] The weight of the deposited material in the battery and the discharging capacity of the second circle and the average discharging voltage are used for calculation, and the energy density of the battery is 491 Wh / kg.

[0137] Example 4

[0138] A kind of all-solid-state thin film battery, different from the embodiment 1, the S layer thickness is 300 nm, the Na3PO4 layer thickness is 500 nm, and the NaSn alloy layer thickness is 1000 nm.The preparation method of this all-solid-state thin film battery is same with the embodiment 1 except using S target instead of Na2S target, using NaSn alloy target instead of Sn target, here is not described.

[0139] Performance detection:

[0140] The film thickness is obtained by film thickness gauge, and the weight of sulfur in the battery is 70.8 ug, the weight of sodium phosphate is 8.1 ug, and the weight of sodium-tin alloy is 96.8 ug.

[0141] The small soft package battery is charged and discharged by using battery charging and discharging system (Shenglan battery tester SLAN-CT2001A).

[0142] The first circle charging current is 0.5 uA, and the discharging current is 0.5 uA.The test results show that the first circle charging capacity of the battery is 1065 mAh / g, the discharging capacity is 905 mAh / g, and the coulomb efficiency is 85%.

[0143] The second circle charging current is 1 uA, and the discharging current is 1 uA.The second circle charging capacity is 1017 mAh / g, the discharging capacity is 976 mAh / g, and the coulomb efficiency is 96%.

[0144] The third circle charging current is 1 uA, and the discharging current is 2.5 uA.The third circle charging capacity is mAh / g, the discharging capacity is 876 mAh / g, and the coulomb efficiency is 95%.

[0145] The fifth circle charging current is 1 uA, and the discharging current is 1 uA.Under the same charging and discharging conditions, the 103rd circle capacity after discharging 100 times is 922 mAh / g, the discharging capacity is 903 mAh / g, and the coulomb efficiency is 98%.

[0146] The discharging capacity of the third circle compared with the discharging capacity of the second circle, the maintenance rate of discharging capacity is %, indicating that the discharging rate performance is good after the discharging current is increased by 5 times.

[0147] The discharging capacity of the fourth circle compared with the discharging capacity of the second circle, the maintenance rate of discharging capacity is 90%, indicating that the discharging rate performance is good after the discharging current is increased by 2.5 times.

[0148] The discharging capacity of the 103rd circle compared with the discharging capacity of the 4th circle, the maintenance rate of discharging capacity is 92%, indicating that the cycle performance is good after 100 times of cycle charging and discharging.

[0149] The energy density of the battery is calculated to be 747 Wh / kg using the weight of the deposited material in the battery and the discharge capacity and average discharge voltage of the second cycle.

[0150] Comparative Example 1

[0151] A full solid-state thin film battery, which differs from Example 1 in that the plating time of the positive electrode layer plating stage is extended, and the thickness of the positive electrode layer prepared is 75 μm. The others are the same as Example 1. Here is not elaborated.

[0152] The battery performance test is carried out using the same battery test method as Example 1. The first cycle charge capacity of the battery is 69 mAh / g, the discharge capacity is 44 mAh / g, and the coulombic efficiency is 64%.

[0153] The comparative test results show that the thickness of the positive electrode thin film layer is increased to 75 μm, and the battery performance of the thin film battery prepared is significantly decreased.

[0154] Comparative Example 2

[0155] A full solid-state thin film battery, which differs from Example 1 in that the plating time of the solid electrolyte layer plating stage is extended, and the thickness of the solid electrolyte layer prepared is 75 μm. The others are the same as Example 1. Here is not elaborated.

[0156] The battery performance test is carried out using the same battery test method as Example 1. The first cycle charge capacity of the battery is 23 mAh / g, the discharge capacity is 7 mAh / g, and the coulombic efficiency is 30%.

[0157] The comparative test results show that the thickness of the solid electrolyte layer is increased to 75 μm, and the battery performance of the thin film battery prepared is significantly decreased.

[0158] Comparative Example 3

[0159] A full solid-state thin film battery, which differs from Example 1 in that the plating time of the negative electrode layer plating stage is extended, and the thickness of the negative electrode layer prepared is 75 μm. The others are the same as Example 1. Here is not elaborated.

[0160] The battery performance test is carried out using the same battery test method as Example 1. The first cycle charge capacity of the battery is 115 mAh / g, the discharge capacity is 3 mAh / g, and the coulombic efficiency is 3%.

[0161] The comparative test results show that the thickness of the negative electrode thin film layer is increased to 75 μm, and the battery performance of the thin film battery prepared is significantly decreased.

[0162] The thinnest film layer prepared by the commonly used wet coating method and related process equipment on the market is only about 10 pm thick, and the thin film of the present application cannot be prepared. A full solid-state battery with a thickness of 100 pm is prepared using Na2S as the positive active material by the wet coating method and related process equipment, and the charge and discharge performance effect of the present application cannot be obtained, and the full solid-state thin film battery of the present application cannot be obtained.

[0163] In summary, the full solid-state thin film battery prepared by using the technical solutions provided in the present application has very high battery energy density, far exceeding the products on the market. And in the process of repeated charging and discharging, it shows excellent discharge rate and cycle performance, effectively improving the battery capacity.

[0164] The specific embodiments are only an explanation of the present application, and are not a limitation of the present application. Those skilled in the art can make modifications to the embodiments without creative contribution after reading the present specification, but as long as the modifications are within the scope of the claims of the present application, they are protected by the patent law.

Claims

1. An all-solid-state thin-film battery, characterized by comprising: The full solid-state thin film battery comprises a positive electrode current collector layer, a positive electrode layer, a solid-state electrolyte layer, a negative electrode layer, and a negative electrode current collector layer. The positive electrode layer, the solid-state electrolyte layer, and the negative electrode layer are sequentially connected. The positive electrode current collector layer is arranged on the side of the positive electrode layer away from the solid-state electrolyte layer, and the negative electrode current collector layer is arranged on the side of the negative electrode layer away from the solid-state electrolyte layer. Alternatively, the positive electrode current collector layer is arranged on one side of the positive electrode layer, the solid-state electrolyte layer, and the negative electrode layer, and the negative electrode current collector layer is arranged on the other side of the positive electrode layer, the solid-state electrolyte layer, and the negative electrode layer. The thickness of the positive electrode layer is 10 nm-50 μm, and the positive electrode layer is composed of a material containing sulfur elements and having a charge storage capacity. The thickness of the solid-state electrolyte layer is 300 nm-500 nm. When the positive electrode layer is composed of a material containing sulfur elements and metal elements and having a charge storage capacity, the thickness of the negative electrode layer is 0 nm-1 μm; when the positive electrode layer is composed of a material containing sulfur elements and having a charge storage capacity, the thickness of the negative electrode layer is 10 nm-1 μm. The thickness of the positive electrode current collector layer is 10 nm-100 μm. When the negative electrode layer is composed of a material without a charge storage capacity, the thickness of the negative electrode current collector layer is 10 nm-100 μm; when the negative electrode layer is composed of a material with a charge storage capacity, the thickness of the negative electrode current collector layer is 0 nm-100 μm. The material of the positive electrode layer is sodium sulfide or sulfur. The material of the negative electrode layer is tin or sodium-tin alloy. The material of the solid-state electrolyte layer is Na3PO4. The positive electrode layer, the solid-state electrolyte layer, and the negative electrode layer are all plated by vacuum plating or magnetron sputtering.

2. The all-solid-state thin film battery of claim 1, wherein: The weight content of the material with a charge storage capacity in the positive electrode layer is 20%-100%.

3. The all-solid-state thin film battery of claim 1, wherein: The weight content of the material with a charge storage capacity in the negative electrode layer is 50%-100%.

4. The all-solid-state thin film battery of claim 1, wherein: The positive electrode layer is a dense film.

5. A method of making an all-solid-state thin film battery based on any one of claims 1-4, characterized by: When the full solid-state thin film battery is plated by vacuum evaporation, the preparation method comprises the following steps: Step 1: Set the positive electrode current collector layer as the film deposition substrate, vacuum extraction to 1.0 x 10 -3 Pa or below; Step 2: Adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated positive electrode layer material deposit on the thin film deposition substrate, until the cumulative deposition thickness reaches the target thickness, to form the positive electrode layer. Step 3: Adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated solid-state electrolyte layer deposit on the positive electrode layer, until the cumulative deposition thickness reaches the target thickness, to form the solid-state electrolyte layer. Step 4: Adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated negative electrode layer deposit on the solid-state electrolyte layer material, until the cumulative deposition thickness reaches the target thickness, to form the negative electrode layer. Step 5: Adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated negative electrode current collector material deposit on the negative electrode layer material, until the cumulative deposition thickness reaches the target thickness, to form the negative electrode current collector layer. The full solid-state thin film battery is obtained.

6. A method of making an all-solid-state thin film battery based on any one of claims 1-4, characterized by: When the full solid-state thin film battery is plated by magnetron sputtering, the preparation method comprises the following steps: Step 1: Set the positive electrode current collector layer as the film deposition substrate, vacuumize to 1.0 x 10 -3 Pa or below, and then introduce inert gas; Step 2: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, make the sputtered positive electrode layer material deposited on the thin film deposition substrate, until the cumulative deposition thickness reaches the target thickness, forming a positive electrode layer; Step 3: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, make the sputtered solid electrolyte layer deposited on the positive electrode layer material, until the cumulative deposition thickness reaches the target thickness, forming a solid electrolyte layer; Step 4: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, make the sputtered negative electrode layer deposited on the solid electrolyte layer material, until the cumulative deposition thickness reaches the target thickness, forming a negative electrode layer; Step 5: adjust the current power, when the film thickness change rate reaches 0.1-0.5 nm / s, make the sputtered negative electrode current collector material deposited on the negative electrode layer material, until the cumulative deposition thickness reaches the target thickness, forming a negative electrode current collector layer; obtain a full solid-state thin film battery.

7. A method of making an all-solid-state thin film battery based on any one of claims 1-4, characterized by: When the positive electrode layer and the negative electrode layer of the full solid-state thin film battery are plated by vacuum plating, and the solid electrolyte layer is plated by magnetron sputtering, the following steps are included: Step 1: Set the positive electrode current collector layer as the film deposition substrate, vacuum extraction to 1.0 x 10 -3 Pa or below; Step 2: adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated positive electrode layer material deposited on the thin film deposition substrate, until the cumulative deposition thickness reaches the target thickness, forming a positive electrode layer; Step 3: pass in inert gas, adjust the jet power, when the film thickness change rate reaches 0.1-0.5 nm / s, make the sputtered solid electrolyte layer deposited on the positive electrode layer material, until the cumulative deposition thickness reaches the target thickness, forming a solid electrolyte layer; Step 4: stop passing in inert gas, adjust the evaporation current, when the film thickness change rate reaches 0.1-0.5 nm / s, make the evaporated negative electrode layer deposited on the solid electrolyte layer material, until the cumulative deposition thickness reaches the target thickness, forming a negative electrode layer; obtain a full solid-state thin film battery.

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