Wide-temperature-range all-solid-state thin film battery and preparation method and application thereof

Abstract

The application discloses a kind of wide temperature range all-solid-state thin film batteries and preparation method and application thereof.The battery includes substrate, negative electrode current collector, composite negative electrode structure, solid electrolyte layer, positive electrode layer and positive electrode current collector from bottom to top in turn;The composite negative electrode structure is any one of two-layer structure, three-layer structure and laminated structure;When the composite negative electrode structure is two-layer structure, composite negative electrode structure is successively composed of lithium supplement layer and negative electrode layer from bottom to top;When the composite negative electrode structure is three-layer structure, composite negative electrode structure is successively composed of bottom lithium supplement layer, negative electrode layer and top lithium supplement layer from bottom to top;When the composite negative electrode structure is laminated structure, composite negative electrode structure is the laminated composite structure formed by lithium supplement layer and negative electrode layer in turn alternately deposited.The application constructs the composite negative electrode structure capable of long-term stable operation in wide temperature range by layer structure design and process control, realizes the multiple functions of lithium supplement, interface anchoring and stress buffering.

Description

Technical Field

[0001] This invention relates to the field of all-solid-state battery technology, specifically to a wide-temperature-range all-solid-state thin-film battery, its preparation method, and its application. Background Technology

[0002] With the rapid development of the Internet of Things, wearable devices, and implantable medical electronics, microelectronic systems are constantly evolving towards miniaturization and integration, creating an increasingly urgent demand for on-chip integrated power supplies. All-solid-state thin-film batteries, due to their outstanding advantages such as small size, high energy density, long cycle life, and no risk of leakage, are considered an ideal on-chip micro-power solution.

[0003] In existing technologies, all-solid-state thin-film batteries are mainly based on the LiCoO2 / LiPON / Li system. Some companies have launched related micro-thin-film battery products, but none have achieved large-scale commercial application. In the LiCoO2 / LiPON / Li system, the positive electrode LiCoO2 film needs to be annealed at a high temperature above 500℃. This process condition seriously conflicts with the thermal budget of the back-end fabrication process of integrated circuits, greatly limiting its on-chip integration. At the same time, the low melting point (180.5℃) of the lithium metal anode severely restricts the overall thermal tolerance of the device: on the one hand, this characteristic makes it difficult for it to withstand the high-temperature processes involved in microelectronics fabrication; on the other hand, it also limits the long-term stable power supply of the device in wide-temperature-range application scenarios such as automotive electronics, aerospace, and oil drilling.

[0004] To overcome the melting point limitation of lithium metal anodes, researchers have attempted to replace lithium metal with high-capacity, high-melting-point anode materials such as silicon, tin, and germanium to improve the battery's wide-temperature adaptability. However, these materials suffer from a prominent problem of low initial coulombic efficiency. To address this, existing technologies have proposed various lithium replenishment methods. For example, Chinese invention patent CN114725325A discloses a method for depositing lithium metal on the surface of a silicon-based anode and then heating it to form a lithium alloy. However, existing lithium replenishment technologies generally suffer from the following common problems: single-layer lithium deposition is prone to cracking due to internal stress, and the thickness of the lithium layer is limited by the diffusion distance of lithium in the anode material. Excessively thick lithium cannot react completely, resulting in material waste and residual lithium metal posing safety risks, making it difficult to meet the requirements of high-energy-density batteries for thick-film anodes. Furthermore, the entire anode layer separates the surface lithium alloy layer from the current collector, resulting in weak solid-solid interface bonding. During temperature cycling, the volume expansion of the anode causes concentrated stress on the surface alloy layer, accelerating its failure.

[0005] Therefore, how to achieve effective lithium replenishment while constructing a stable anode interface structure over a wide temperature range, breaking through thickness limitations to improve energy density, and achieving high-quality interface bonding of each functional layer has become a technical challenge that urgently needs to be solved in this field. Summary of the Invention

[0006] The purpose of this invention is to overcome the shortcomings of existing technologies and provide a wide-temperature-range all-solid-state thin-film battery, its fabrication method, and its applications. Through innovative layered structure design and process control, this invention constructs a gradient composite anode structure capable of long-term stable operation over a wide temperature range, achieving multiple functions such as lithium replenishment, interface anchoring, and stress buffering. This solves the technical problems of incompatibility between existing devices and integrated circuit processes, difficulty in withstanding microelectronic fabrication processes, and challenges in wide-temperature-range applications.

[0007] To achieve the above objectives, the technical solution designed by the present invention is as follows:

[0008] This invention provides a wide-temperature-range all-solid-state thin-film battery, the battery comprising, from bottom to top, a substrate, a negative electrode current collector, a composite negative electrode structure, a solid electrolyte layer, a positive electrode layer, and a positive electrode current collector;

[0009] The composite negative electrode structure can be any one of a two-layer structure, a three-layer structure, or a stacked structure.

[0010] When the composite anode structure is a two-layer structure, the composite anode structure consists of a lithium replenishment layer and an anode layer from bottom to top.

[0011] When the composite negative electrode structure is a three-layer structure, the composite negative electrode structure consists of a bottom lithium replenishment layer, a negative electrode layer and a top lithium replenishment layer from bottom to top.

[0012] When the composite negative electrode structure is a stacked structure, it is a stacked composite structure formed by alternating deposition of a lithium replenishment layer and a negative electrode layer for 3 to 12 times.

[0013] Furthermore, the substrate can be either a silicon wafer or a quartz wafer;

[0014] The negative electrode current collector is any one of copper, nickel, titanium and stainless steel;

[0015] The lithium replenishment layer is any one of lithium, lithium-silver alloy, lithium-magnesium alloy, lithium-aluminum alloy, lithium-magnesium-aluminum alloy, lithium-tin alloy, lithium-zinc alloy, lithium-copper alloy, lithium-silicon alloy, lithium-boron alloy, lithium nitride, lithium oxide, and lithium fluoride.

[0016] The negative electrode layer is any one of silicon, silicon oxide, tin, tin oxide, germanium, aluminum, and antimony;

[0017] The solid electrolyte layer is any one of lithium phosphorus oxygen nitrogen electrolyte, lithium lanthanum zirconium oxygen electrolyte, and lithium lanthanum titanium oxygen electrolyte.

[0018] The positive electrode layer is vanadium pentoxide and V6O. 13 Any one of chromium pentoxide and manganese dioxide;

[0019] The positive electrode current collector is any one of platinum, gold, copper, aluminum, and nickel.

[0020] Furthermore, the thickness of the negative electrode current collector is 100~500 nm; the thickness of the lithium replenishment layer is 20~200 nm; the thickness of the negative electrode layer is 40~500 nm; the thickness of the solid electrolyte layer is 1~3 μm; the thickness of the positive electrode layer is 100~500 nm; and the thickness of the positive electrode current collector is 100~500 nm.

[0021] Furthermore, the substrate is a silicon wafer; the negative electrode current collector is copper with a thickness of 300 nm;

[0022] The composite anode structure is a stacked structure, with the lithium replenishment layer and the anode layer deposited alternately four times. The thickness of the lithium replenishment layer is 60 nm, and the thickness of the anode layer is 40 nm.

[0023] The solid electrolyte layer is a lithium-phosphorus-oxygen-nitrogen electrolyte with a thickness of 1.5 μm;

[0024] The positive electrode layer is vanadium pentoxide with a thickness of 300 nm;

[0025] The positive electrode current collector is platinum with a thickness of 300 nm.

[0026] The present invention also provides a method for preparing the battery, comprising the following steps:

[0027] (1) The substrate is cleaned and dried sequentially;

[0028] (2) A negative current collector is deposited on the surface of a dried substrate using magnetron sputtering technology;

[0029] (3) A composite negative electrode structure is deposited on the surface of the negative electrode current collector using thin film deposition technology. When the composite negative electrode structure is a two-layer structure, the lithium replenishment layer and the negative electrode layer are deposited in sequence.

[0030] When the composite anode structure is a three-layer structure, the bottom lithium replenishment layer, the anode layer and the top lithium replenishment layer are deposited sequentially.

[0031] When the composite anode structure is a multilayer structure, lithium replenishment layer and anode layer are deposited alternately 3 to 12 times in sequence;

[0032] (4) A solid electrolyte layer is deposited on the surface of the composite negative electrode structure using magnetron sputtering technology;

[0033] (5) A positive electrode layer is deposited on the surface of a solid electrolyte layer using magnetron sputtering technology;

[0034] (6) A positive current collector is deposited on the surface of the positive electrode layer using magnetron sputtering technology;

[0035] (7) The battery after deposition is heated to 100~200℃ and then heat-treated to obtain a wide temperature range all-solid-state thin film battery.

[0036] Further, in step (1), the cleaning specifically involves: ultrasonically cleaning the substrate in acetone, anhydrous ethanol, and water in sequence;

[0037] In step (2), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the power of magnetron sputtering is 50~100 W, the pressure of magnetron sputtering is 0.5~1 Pa, and the flow rate of argon gas is 50~100 sccm;

[0038] In step (3), when depositing the lithium replenishment layer, vacuum thermal evaporation technology is used, with a vacuum degree of <3×10⁻⁶. -4 Pa; When depositing the negative electrode layer, magnetron sputtering technology is used, and the vacuum degree of magnetron sputtering is 3×10. -4 The magnetron sputtering power is 50~100W, the magnetron sputtering pressure is 0.5~1 Pa, and the argon flow rate is 50~100 sccm.

[0039] Furthermore, in step (2), the magnetron sputtering power is 50 W, the magnetron sputtering pressure is 0.5 Pa, and the argon flow rate is 50 sccm;

[0040] In step (3), when depositing the negative electrode layer, the magnetron sputtering power is 50 W, the magnetron sputtering pressure is 0.5 Pa, and the argon flow rate is 50 sccm.

[0041] Furthermore, in step (4), the vacuum degree of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the power of magnetron sputtering is 80~100 W, the pressure of magnetron sputtering is 0.5~1 Pa, and the flow rate of nitrogen is 50~100 sccm;

[0042] In step (5), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the power of magnetron sputtering is 50~100 W, the pressure of magnetron sputtering is 0.5~1 Pa, the flow rate of argon is 50~100 sccm, and the flow rate of oxygen is 10~15 sccm;

[0043] In step (6), the magnetron sputtering power is 50~100 W, the magnetron sputtering pressure is 0.5~1 Pa, and the argon flow rate is 50~100 sccm.

[0044] In step (7), the heating rate is 1~10℃ / min, the heat treatment temperature is 100~200℃, and the heat treatment time is 30~120 min.

[0045] Furthermore, in step (4), the vacuum degree of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the magnetron sputtering power is 100 W, the magnetron sputtering pressure is 0.5 Pa, and the nitrogen flow rate is 50 sccm;

[0046] In step (5), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, magnetron sputtering power is 10 W, magnetron sputtering pressure is 0.5 Pa, argon flow rate is 50 sccm, and oxygen flow rate is 10 sccm;

[0047] In step (6), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the magnetron sputtering power is 50 W, the magnetron sputtering pressure is 0.5 Pa, and the argon flow rate is 50 sccm;

[0048] In step (7), the heating rate is 5~10℃ / min, the heat treatment temperature is 100~200℃, and the heat treatment time is 30~120 min.

[0049] The present invention also provides an application of the battery described herein in automotive electronics, aerospace, and oil drilling.

[0050] The principle of this invention:

[0051] 1. This invention fundamentally overcomes the thickness limitations of traditional single-layer lithium replenishment by employing a multi-layer composite structure with alternating deposition of lithium replenishment and anode layers. In traditional single-layer lithium replenishment processes, the lithium layer thickness is constrained by two factors: firstly, the accumulation of internal stress during thick lithium film deposition easily leads to film cracking; secondly, the solid-state diffusion distance of lithium in the anode material is limited, and an excessively thick lithium layer cannot fully react with the anode, resulting in wasted lithium resources and residual metallic lithium posing safety risks. This invention disperses the thick lithium layer into multiple thin layers, controlling the thickness of each layer within the diffusion distance range. Through layer-by-layer deposition, it ensures that each lithium layer can fully react with the adjacent anode layer.

[0052] 2. The deposited battery undergoes heat treatment to diffuse lithium from the lithium replenishment layer into the negative electrode layer, forming a continuous gradient lithium distribution from the current collector to the electrolyte within the composite negative electrode structure. After heat treatment, the lithium content is higher near the current collector, forming a chemical anchoring layer at the current collector interface to firmly fix the negative electrode; the lithium content in the middle region transitions gradually, effectively buffering volume expansion stress and thermal stress; the lithium-rich region near the electrolyte forms a gradual transition interface with the solid electrolyte, avoiding the abrupt interface changes and stress concentrations of traditional surface lithium replenishment. Heat treatment also releases internal stress generated during the multilayer thin film deposition process, improving interfacial contact between functional layers and promoting interfacial fusion.

[0053] The beneficial effects of this invention are:

[0054] (1) The present invention uses vanadium oxide and other cathode materials that do not require high-temperature annealing, and the entire preparation process is below 300°C, which is perfectly compatible with the back-end process of integrated circuits. At the same time, a high melting point anode is used to replace metallic lithium, so that the battery can work stably in a wide temperature range of -40°C to 250°C, which solves the technical problem that the traditional LiCoO2 / Li system cannot take into account both on-chip integration and wide temperature range application due to high-temperature annealing and lithium melting point limitations.

[0055] (2) In this invention, the lithium replenishment layer and the negative electrode layer are deposited alternately to form a continuous gradient lithium distribution from the current collector to the electrolyte. The bottom lithium layer forms a chemical anchoring layer at the interface, which firmly fixes the negative electrode to the current collector; the gradient lithium distribution in the middle effectively buffers the volume expansion stress and thermal stress; the top lithium-rich area forms a gradual transition interface with the solid electrolyte, avoiding the interface abruptness and stress concentration problems of traditional surface lithium replenishment.

[0056] (3) This invention employs a multilayer structure with alternating deposition of lithium replenishment layers and anode layers, dispersing the thick lithium layer into multiple thin layers. Each lithium layer can fully react with the adjacent anode layer, completely solving the problem of lithium layer thickness being limited by diffusion distance and excessively thick lithium not being able to fully react in single-layer lithium replenishment processes. While ensuring complete lithium utilization, it achieves a composite anode structure with micron-level thickness, significantly improving the active material loading and energy density, and providing a feasible path for the large-capacity development of all-solid-state thin-film batteries. Attached Figure Description

[0057] Figure 1 A cross-sectional SEM image of the wide-temperature-range all-solid-state thin-film battery 2;

[0058] In the diagram, 1 represents the positive electrode layer; 2 represents the solid electrolyte layer; and 3 represents the composite negative electrode structure.

[0059] Figure 2 The graph shows the room temperature cycling performance of the wide-temperature-range all-solid-state thin-film battery 2.

[0060] Figure 3 The low-temperature cycling performance test results for the wide-temperature-range all-solid-state thin-film battery 3 are shown in the figure.

[0061] Figure 4 The high-temperature cycling performance test results for the wide-temperature-range all-solid-state thin-film battery 3 are shown in the figure.

[0062] Figure 5 The high-temperature cycling performance test results for the wide-temperature-range all-solid-state thin-film battery 4 are shown in the figure.

[0063] Figure 6 This is a graph showing the high-temperature cycling performance of the all-solid-state thin-film battery D1. Detailed Implementation

[0064] The present invention will now be described in further detail with reference to specific embodiments, so that those skilled in the art can understand it.

[0065] Example 1

[0066] Wide-temperature-range all-solid-state thin-film battery 1

[0067] The wide-temperature-range all-solid-state thin-film battery 1 includes, from bottom to top, a substrate, a negative electrode current collector, a composite negative electrode structure, a solid electrolyte layer, a positive electrode layer, and a positive electrode current collector;

[0068] Among them, the composite negative electrode structure can be any one of a two-layer structure, a three-layer structure, and a stacked structure;

[0069] When the composite anode structure is a two-layer structure, the composite anode structure consists of a lithium supplement layer and an anode layer from bottom to top.

[0070] When the composite anode structure is a three-layer structure, the composite anode structure consists of a bottom lithium replenishment layer, an anode layer and a top lithium replenishment layer from bottom to top.

[0071] When the composite anode structure is a stacked structure, the composite anode structure is a stacked composite structure formed by alternating deposition of lithium replenishment layer and anode layer 3-12 times, with the bottom layer being the lithium replenishment layer.

[0072] The substrate can be either a silicon wafer or a quartz wafer;

[0073] The negative electrode current collector can be any one of copper, nickel, titanium and stainless steel, and the thickness of the negative electrode current collector is 100~500nm;

[0074] The lithium replenishment layer is any one of lithium, lithium silver alloy, lithium magnesium alloy, lithium aluminum alloy, lithium magnesium aluminum alloy, lithium tin alloy, lithium zinc alloy, lithium copper alloy, lithium silicon alloy, lithium boron alloy, lithium nitride, lithium oxide, and lithium fluoride, and the thickness of the lithium replenishment layer is 20~200nm.

[0075] The negative electrode layer is any one of silicon, silicon oxide, tin, tin oxide, germanium, aluminum and antimony, and the thickness of the negative electrode layer is 40~500 nm;

[0076] The solid electrolyte layer is any one of lithium phosphorus oxygen nitrogen electrolyte, lithium lanthanum zirconium oxygen electrolyte, and lithium lanthanum titanium oxygen electrolyte, and the thickness of the solid electrolyte layer is 1~3 μm.

[0077] The positive electrode layer is vanadium pentoxide and V6O. 13 The cathode layer consists of any one of chromium pentoxide and manganese dioxide, with a thickness of 100~500 nm.

[0078] The positive electrode current collector can be any one of platinum, gold, copper, aluminum and nickel, and the thickness of the positive electrode current collector is 100~500 nm.

[0079] Example 2

[0080] Fabrication of wide-temperature-range all-solid-state thin-film battery 2

[0081] 1. Substrate cleaning: Place a 2.5 cm × 2.5 cm silicon wafer in acetone, anhydrous ethanol and deionized water in sequence, and perform ultrasonic cleaning for 1 hour in each. After cleaning, place it in an oven to dry.

[0082] 2. Negative Electrode Current Collector Deposition: The dried silicon wafer obtained in step 1) is fixed on the substrate, a 0.7cm × 1cm window-sized mask is attached, and the wafer is placed in a magnetron sputtering apparatus (Wuhan Pudi Vacuum Technology Co., Ltd., model PD-400), with a copper target placed in between. A mechanical pump and a molecular pump are used to evacuate the chamber until the vacuum level reaches 3 × 10⁻⁶. -4 At Pa, the DC power supply was turned on, and a copper target was sputtered using 50 W, 0.5 Pa working pressure, and 50 sccm Ar gas flow. The deposition was carried out for 30 min to prepare a copper thin film with a thickness of 300 nm as the negative electrode current collector.

[0083] 3. Composite Anode Structure Deposition: The composite anode structure in this embodiment is a stacked structure, with the lithium replenishment layer and the anode layer deposited alternately four times. The preparation methods of the lithium replenishment layer and the anode layer are as follows:

[0084] (1) Preparation of the lithium replenishment layer: A mask with a window size of 0.5cm × 0.5cm is attached to the film sputtered in step 2 and placed in a vacuum thermal evaporation apparatus (Wuhan Pudi Vacuum Technology Co., Ltd., model PD-400s), and a lithium metal evaporation source is placed in it at the same time. The chamber is evacuated using a mechanical pump and a molecular pump. When the vacuum level is lower than 3 × 10 -4 At Pa, the evaporation power supply is turned on, and a lithium metal thin film with a thickness of 60 nm is deposited as a lithium replenishment layer.

[0085] (2) Negative electrode layer preparation: After each lithium replenishment layer is deposited, the evaporation power supply is turned off, the chamber is kept in a vacuum state, and left to stand for 2-15 minutes as the interface relaxation time to release the deposition internal stress. The original mask is kept unchanged on the film sputtered in step (1), and placed in the magnetron sputtering equipment, while the silicon target is placed in. The chamber is evacuated using a mechanical pump and a molecular pump. When the vacuum degree reaches 3×10 -4 At Pa, the RF power supply was turned on, and RF sputtering of the silicon target was performed using 50 W, 0.5 Pa working pressure, and 50 sccm Ar gas flow. The deposition was carried out for 10 min to prepare a silicon thin film with a thickness of 40 nm as the negative electrode layer.

[0086] 4. Solid Electrolyte Layer Deposition: A 1cm × 1cm window mask is attached to the sputtered film from step 3 and placed in a magnetron sputtering apparatus, along with a lithium phosphate target. A mechanical pump and a molecular pump are used to evacuate the chamber until a vacuum of 3 × 10⁻⁶ is achieved. -4 At Pa, the RF power supply was turned on, and RF sputtering of a lithium phosphate target was performed using 100 W, 0.5 Pa working pressure, and 50 sccm N2 gas flow. The deposition was carried out for 4 h to prepare a 1.5 μm thick LiPON thin film as a solid electrolyte layer.

[0087] 5. Positive layer deposition: A 0.5 cm × 0.5 cm window-sized mask is attached to the film sputtered in step 4, and the film is placed in a magnetron sputtering apparatus, along with a vanadium pentoxide target. A mechanical pump and a molecular pump are used to evacuate the chamber until the vacuum level reaches 3 × 10⁻⁶. -4 At Pa, the RF power supply was turned on, and RF sputtering of vanadium oxide target was performed using 100 W, 0.5 Pa working pressure, 50 sccm Ar + 10 sccm O2 gas flow. The deposition was carried out for 3 h to prepare a vanadium oxide thin film with a thickness of 300 nm as the positive electrode layer (deposited at room temperature, without annealing).

[0088] 6. Positive Current Collector Deposition: A 0.7cm × 1cm window mask is attached to the sputtered film from step 5 and placed in a magnetron sputtering apparatus, along with a platinum target. A mechanical pump and a molecular pump are used to evacuate the chamber until a vacuum of 3 × 10⁻⁶ is achieved. -4 At Pa, the DC power supply was turned on, and a platinum target was sputtered by DC with a working pressure of 50 W, 0.5 Pa, and Ar gas flow of 50 sccm for 10 min to prepare a platinum film with a thickness of 300 nm as the positive electrode current collector.

[0089] 7. Multifunctional heat treatment: The deposited battery is heated to 100~200℃ in a vacuum or inert gas protective atmosphere, and then subjected to heat treatment. The heating rate is 1~10℃ / min, the heat treatment temperature is 100~200℃, and the heat treatment time is 30~120 min. A wide-temperature-range all-solid-state thin-film battery is thus prepared.

[0090] SEM analysis was performed on the cross-section of the wide-temperature-range all-solid-state thin-film battery 2, and the results are as follows: Figure 1 As shown, the interfaces between the functional layers are clear and tightly bonded, without defects such as delamination, cracks or holes, indicating that a structurally complete, dense and uniform all-solid-state thin-film battery was successfully prepared using magnetron sputtering and vacuum thermal evaporation processes.

[0091] Cyclic performance tests were conducted on the wide-temperature-range all-solid-state thin-film battery 2 at room temperature, and the results are as follows: Figure 2As shown, after 100 charge-discharge cycles at room temperature, the battery maintains a stable capacity with no significant capacity decay. This indicates that the transition metal vanadium oxide cathode material used in this invention, which requires no annealing, possesses good electrochemical reversibility and structural stability, excellent interfacial compatibility with the solid electrolyte layer, and can support long-term stable battery cycling.

[0092] Example 3

[0093] Fabrication of wide-temperature-range all-solid-state thin-film batteries

[0094] The preparation method of the wide-temperature-range all-solid-state thin-film battery 3 in this embodiment is the same as that in embodiment 2, except that the silicon wafer is replaced with a quartz wafer to prepare the wide-temperature-range all-solid-state thin-film battery 3.

[0095] The prepared wide-temperature-range all-solid-state thin-film battery 3 was tested over a wide temperature range. The results are as follows: Figure 3 As shown, the wide-temperature-range all-solid-state thin-film battery 3 can still perform stable charging and discharging in a low-temperature environment (-10℃), indicating that the non-annealing cathode material and high-melting-point anode system used in this invention have good ion transport capabilities and electrochemical activity under low-temperature conditions.

[0096] The high-temperature performance of the prepared wide-temperature-range all-solid-state thin-film battery 3 was tested, and the results are as follows: Figure 4 As shown, the wide-temperature-range all-solid-state thin-film battery 3 can stably cycle 50 times in an extreme high-temperature environment of 250℃, verifying the reliability and structural stability of the high-melting-point anode material and the anneal-free cathode system used in this invention in a wide temperature range.

[0097] Example 4

[0098] Fabrication of wide-temperature-range all-solid-state thin-film batteries

[0099] The preparation method of the wide-temperature-range all-solid-state thin-film battery 4 in this embodiment is the same as that in embodiment 3, except that the lithium replenishment layer and the negative electrode layer are deposited alternately 12 times, and the deposition time of the positive electrode layer is changed to 12 hours to prepare the wide-temperature-range all-solid-state thin-film battery 4.

[0100] The high-temperature performance of the prepared wide-temperature-range all-solid-state thin-film battery 4 was tested, and the results are as follows: Figure 5 As shown, the battery can stably cycle for more than 50 times under extreme high temperature conditions of 250℃, and the capacity is significantly improved. This verifies the effectiveness of the multilayer stacked structure of this invention in achieving high-load thick films, breaks through the thickness limitation of single-layer lithium replenishment, and provides a feasible path for the large-capacity of all-solid-state thin-film batteries.

[0101] Comparative Example 1

[0102] Fabrication of all-solid-state thin-film battery D1

[0103] 1. Substrate cleaning: Place a 2.5 cm × 2.5 cm silicon wafer in acetone, ethanol and deionized water in sequence, and perform ultrasonic cleaning for 1 hour each.

[0104] 2. Negative electrode current collector deposition: Same as step 2 in Example 2.

[0105] 3. Negative electrode structure deposition: The composite negative electrode structure in this embodiment is a single-layer lithium replenishment layer. The negative electrode layer and the lithium replenishment layer are sputtered sequentially. The preparation methods of the negative electrode layer and the lithium replenishment layer are as follows:

[0106] (1) Anode layer preparation: A 0.5cm × 0.5cm window mask is attached to the film sputtered in step 2, and the film is placed in a magnetron sputtering apparatus, along with a silicon target. A mechanical pump and a molecular pump are used to evacuate the chamber until the vacuum level reaches 3 × 10⁻⁶. -4 At Pa, the RF power supply was turned on, and RF sputtering of the silicon target was performed using 50 W, 0.5 Pa working pressure, and 50 sccm Ar gas flow. The deposition time was 40 min to prepare a silicon thin film with a thickness of 160 nm as the negative electrode layer.

[0107] (2) Preparation of the lithium replenishment layer: The original mask is kept unchanged on the film sputtered in step (1), and placed in a vacuum thermal evaporation apparatus (Wuhan Pudi Vacuum Technology Co., Ltd., model PD-400s), with a lithium metal evaporation source simultaneously placed inside. A mechanical pump and a molecular pump are used to evacuate the chamber. When the vacuum level is below 3 × 10⁻⁶, the evaporation process is complete. -4 At Pa, the evaporation power supply is turned on to deposit a lithium metal film with a thickness of 240 nm as a lithium replenishment layer; the evaporation power supply is turned off, the chamber is kept in a vacuum state, and left to stand for 2~15 minutes as the interface relaxation time to release the deposition internal stress.

[0108] 4. Solid electrolyte layer deposition: Same as step 4 in Example 2.

[0109] 5. Positive electrode layer deposition: Same as step 5 in Example 2.

[0110] 6. Positive current collector deposition: Same as step 6 in Example 2.

[0111] 7. Multifunctional heat treatment: Same as step 7 in Example 2. The all-solid-state thin-film battery D1 is thus prepared.

[0112] The results are as follows Figure 6 As shown, compared to Example 2, the all-solid-state thin-film battery D1 adopts a single-layer pre-lithiation structure and rapidly decays and fails under extreme high temperature conditions of 250°C, indicating that the multi-layer alternating deposition structure of the present invention has better high-temperature stability and interface reliability.

[0113] All other parts not described in detail are existing technologies. Although the above embodiments have provided a detailed description of the present invention, they are only some embodiments of the present invention, not all embodiments. People can obtain other embodiments based on these embodiments without creative effort, and these embodiments all fall within the protection scope of the present invention.

Claims

1. A wide-temperature-range all-solid-state thin-film battery, characterized in that: The battery comprises, from bottom to top, a substrate, a negative electrode current collector, a composite negative electrode structure, a solid electrolyte layer, a positive electrode layer, and a positive electrode current collector; The composite anode structure is a stacked composite structure formed by alternating deposition of a lithium replenishment layer and an anode layer 3 to 12 times. The bottom layer of the composite anode structure is a lithium replenishment layer; The substrate is either a silicon wafer or a quartz wafer; The negative electrode current collector is any one of copper, nickel, titanium and stainless steel; The lithium replenishment layer is any one of lithium, lithium-silver alloy, lithium-magnesium alloy, lithium-aluminum alloy, lithium-magnesium-aluminum alloy, lithium-tin alloy, lithium-zinc alloy, lithium-copper alloy, lithium-silicon alloy, lithium-boron alloy, lithium nitride, lithium oxide, and lithium fluoride. The negative electrode layer is any one of silicon, silicon oxide, tin, tin oxide, germanium, aluminum, and antimony; The solid electrolyte layer is any one of lithium phosphorus oxy nitrogen electrolyte, lithium lanthanum zirconium oxy electrolyte, and lithium lanthanum titanium oxy electrolyte. The positive electrode layer is vanadium pentoxide and V6O. 13 Any one of chromium pentoxide and manganese dioxide; The positive electrode current collector is any one of platinum, gold, copper, aluminum and nickel; The thickness of the negative electrode current collector is 100~500 nm; the thickness of the lithium replenishment layer is 20~200 nm; the thickness of the negative electrode layer is 40~500 nm; the thickness of the solid electrolyte layer is 1~3 μm; the thickness of the positive electrode layer is 100~500 nm; the thickness of the positive electrode current collector is 100~500 nm. The method for preparing the battery includes the following steps: (1) The substrate is cleaned and dried sequentially; (2) A negative current collector is deposited on the surface of a dried substrate using magnetron sputtering technology; (3) A composite negative electrode structure is deposited on the surface of the negative electrode current collector using a thin film deposition process, and lithium replenishment layer and negative electrode layer are deposited alternately 3 to 12 times in sequence; After each lithium replenishment layer is deposited, the chamber is kept in a vacuum state and left to stand for 2 to 15 minutes as an interface relaxation time to release the internal stress of the deposition before depositing the negative electrode layer. (4) A solid electrolyte layer is deposited on the surface of the composite negative electrode structure using magnetron sputtering technology; (5) A positive electrode layer is deposited on the surface of a solid electrolyte layer using magnetron sputtering technology; (6) A positive current collector is deposited on the surface of the positive electrode layer using magnetron sputtering technology; (7) The deposited battery is heated to 100~200℃ and then heat-treated to obtain a wide temperature range all-solid-state thin film battery; After heat treatment, the composite negative electrode structure forms a continuous gradient lithium distribution from the negative electrode current collector to the solid electrolyte layer inside it; the area near the negative electrode current collector is a chemical anchoring layer with high lithium content, the middle area is a gradient transition region, and the area near the solid electrolyte layer is a lithium-rich gradient transition interface layer.

2. The battery according to claim 1, characterized in that: The substrate is a silicon wafer; the negative electrode current collector is copper with a thickness of 300 nm. The composite anode structure consists of alternating deposition of a lithium replenishment layer and an anode layer four times, with the lithium replenishment layer having a thickness of 60 nm and the anode layer having a thickness of 40 nm. The solid electrolyte layer is a lithium-phosphorus-oxygen-nitrogen electrolyte with a thickness of 1.5 μm; The positive electrode layer is vanadium pentoxide with a thickness of 300 nm; The positive electrode current collector is platinum with a thickness of 300 nm.

3. A method for preparing a battery according to any one of claims 1 to 2, characterized in that: Includes the following steps: (1) The substrate is cleaned and dried sequentially; (2) A negative current collector is deposited on the surface of a dried substrate using magnetron sputtering technology; (3) A composite negative electrode structure is deposited on the surface of the negative electrode current collector using a thin film deposition process, and lithium replenishment layer and negative electrode layer are deposited alternately 3 to 12 times in sequence; After each lithium replenishment layer is deposited, the chamber is kept in a vacuum state and left to stand for 2 to 15 minutes as an interface relaxation time to release the internal stress of the deposition before depositing the negative electrode layer. (4) A solid electrolyte layer is deposited on the surface of the composite negative electrode structure using magnetron sputtering technology; (5) A positive electrode layer is deposited on the surface of a solid electrolyte layer using magnetron sputtering technology; (6) A positive current collector is deposited on the surface of the positive electrode layer using magnetron sputtering technology; (7) The deposited battery is heated to 100~200℃ and then heat-treated to obtain a wide temperature range all-solid-state thin film battery; After heat treatment, the composite negative electrode structure forms a continuous gradient lithium distribution from the negative electrode current collector to the solid electrolyte layer inside it; the area near the negative electrode current collector is a chemical anchoring layer with high lithium content, the middle area is a gradient transition region, and the area near the solid electrolyte layer is a lithium-rich gradient transition interface layer.

4. The preparation method according to claim 3, characterized in that: In step (1), the cleaning process specifically involves ultrasonically cleaning the substrate in acetone, anhydrous ethanol, and water in sequence. In step (2), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the power of magnetron sputtering is 50~100 W, the pressure of magnetron sputtering is 0.5~1 Pa, and the flow rate of argon gas is 50~100 sccm; In step (3), when depositing the lithium replenishment layer, vacuum thermal evaporation technology is used, with a vacuum degree of <3×10⁻⁶. -4 Pa; When depositing the negative electrode layer, magnetron sputtering technology is used, and the vacuum degree of magnetron sputtering is 3×10. -4 The magnetron sputtering power is 50~100 W, the magnetron sputtering pressure is 0.5~1 Pa, and the argon flow rate is 50~100 sccm.

5. The preparation method according to claim 4, characterized in that: In step (2), the magnetron sputtering power is 50W, the magnetron sputtering pressure is 0.5 Pa, and the argon flow rate is 50 sccm. In step (3), when depositing the negative electrode layer, the magnetron sputtering power is 50 W, the magnetron sputtering pressure is 0.5 Pa, and the argon flow rate is 50 sccm.

6. The preparation method according to claim 3, characterized in that: In step (4), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the power of magnetron sputtering is 80~100 W, the pressure of magnetron sputtering is 0.5~1 Pa, and the flow rate of nitrogen is 50~100 sccm; In step (5), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the power of magnetron sputtering is 50~100 W, the pressure of magnetron sputtering is 0.5~1 Pa, the flow rate of argon is 50~100 sccm, and the flow rate of oxygen is 10~15 sccm; In step (6), the magnetron sputtering power is 50~100 W, the magnetron sputtering pressure is 0.5~1 Pa, and the argon flow rate is 50~100 sccm. In step (7), the heating rate is 1~10℃ / min, the heat treatment temperature is 100~200℃, and the heat treatment time is 30~120 min.

7. The preparation method according to claim 6, characterized in that: In step (4), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the magnetron sputtering power is 100 W, the magnetron sputtering pressure is 0.5 Pa, and the nitrogen flow rate is 50 sccm; In step (5), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the magnetron sputtering power is 100 W, the magnetron sputtering pressure is 0.5 Pa, the argon flow rate is 50 sccm, and the oxygen flow rate is 10 sccm; In step (6), the vacuum level of magnetron sputtering is 3 × 10⁻⁶. -4 Pa, the magnetron sputtering power is 50 W, the magnetron sputtering pressure is 0.5 Pa, and the argon flow rate is 50 sccm; In step (7), the heating rate is 5~10℃ / min, the heat treatment temperature is 100~200℃, and the heat treatment time is 30~120 min.

8. The application of the battery according to any one of claims 1 to 2 in automotive electronics, aerospace and oil drilling.

Images