Three-dimensional porous negative electrode, preparation method thereof and creep type all-solid-state lithium metal battery
Through the carbon nanotube array and silicon element deposition layer of three-dimensional porous negative electrode material, the volume change problem of solid-state lithium metal batteries during lithium deposition and peeling is solved, the high cycle stability and mechanical stability of the battery are achieved, and a high energy density creep-type all-solid lithium metal battery is constructed.
Patent Information
- Application Number
- CN202510624311.3
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2025-05-15
- Publication Date
- 2025-08-08
AI Technical Summary
The electrode-electrolyte interface caused by volume changes in solid-state lithium metal batteries during lithium deposition and peeling process creates voids. The huge stress generated during the cycle may cause the solid electrolyte to break, forming a lithium dendrites penetration channel, causing the battery to be short-circuited and insufficient mechanical and electrochemical stability.
Using three-dimensional porous negative electrode materials, including carbon-silica porous structures with carbon nanotube arrays and silicon element deposition layers, the uniform deposition and peeling of lithium metal is achieved through the creep mechanism, eliminating the generation of solid electrolyte interface layers, and improving the interface contact and conductivity between the electrode and the electrolyte.
It significantly alleviates the stress problems during the charging and discharging process, improves the cycle stability and life of the battery, enhances the adaptability and mechanical stability of the electrode structure, and builds a creep-type all-solid lithium metal battery with high energy density and good charging and discharging cycle stability.
Smart Images
Figure CN120453342A_ABST
Abstract
Description
Technical Field
[0001] The present invention relates to the technical field of lithium metal batteries, and specifically discloses a three-dimensional porous negative electrode and a preparation method thereof, and a creep-type all-solid-state lithium metal battery. Background Art
[0002] With the development of electric vehicles and large-scale grid energy storage technology, the demand for high-performance batteries continues to grow. Solid-state lithium metal batteries have a high theoretical capacity of lithium metal anodes (3860mAh g -1 ), low electrochemical potential (-3.04 V) and low density (0.53 g cm -3 ), as well as the safety and mechanical strength of solid electrolytes, are considered promising energy storage devices. However, in practical applications, solid-state lithium metal batteries face many challenges. For example, significant volume changes during lithium deposition and stripping can lead to voids at the electrode-electrolyte interface, increasing polarization. The enormous stress generated during cycling can also cause the solid electrolyte to break, forming channels for lithium dendrites to penetrate, ultimately causing the battery to short-circuit.
[0003] To address these challenges, researchers have explored various strategies, such as creating artificial SEI membranes and using three-dimensional electronic or ionic conductors as lithium metal hosts. However, a single material cannot effectively address all of these issues. Furthermore, solid-state lithium metal batteries still face challenges in mechanical and electrochemical stability, particularly regarding their ability to handle lithium's internal stresses and stability in complex environments. Therefore, the development of new materials and technologies is urgently needed to overcome these current challenges. Summary of the Invention
[0004] In order to solve the above problems, the present invention provides a three-dimensional porous negative electrode and a preparation method thereof, and a creep-type all-solid-state lithium metal battery.
[0005] A first aspect of the present invention provides a three-dimensional porous negative electrode material, comprising a carbon-silicon porous material, wherein a lithium metal layer is provided on the carbon-silicon porous material;
[0006] The carbon-silicon porous material includes an electronic conductor and an ion conductor. The electronic conductor is a carbon nanotube array, and the ion conductor is a silicon element deposition layer.
[0007] The three-dimensional porous negative electrode material provided by the present invention possesses unique structural properties that effectively promote the uniform deposition and stripping of lithium metal within the nanotubes through a creep mechanism, allowing the lithium metal to form a "flowable metal liquid" at the nanoscale. This significantly alleviates the stress problems generated during the charge and discharge process and maintains good interface contact between the electrode and the electrolyte. Furthermore, the carbon-silicon porous material provided by the present invention exhibits extremely high stability to lithium metal, which fundamentally eliminates the formation of a solid electrolyte interface layer, thereby improving the battery's cycle stability and lifespan.
[0008] Furthermore, the carbon nanotube array structure provided by the present invention not only significantly improves the overall conductivity of the electrode material but also exhibits excellent adaptability, effectively adapting to the volume changes experienced by the negative electrode material during charge and discharge cycles. This adaptability ensures the integrity of the electrode structure and reduces mechanical damage caused by volume expansion and contraction, thereby further improving battery performance and reliability.
[0009] Preferably, the method for preparing the carbon-silicon porous material comprises the following steps:
[0010] Silicon elements are deposited on the surface of the carbon nanotube array by atomic layer deposition to obtain a carbon-silicon porous material.
[0011] Preferably, the deposition vacuum degree of the atomic layer deposition is (0.5-1.5)×10 -4 Pa, the deposition temperature is 200°C-300°C, and the heating rate to the deposition temperature is 5°C / min-10°C / min.
[0012] Preferably, the silicon element is deposited by introducing SiH4 silicon precursor in a pulsed form, the pulse time is 0.5s-1.5s, and the sweep time is 15s-25s.
[0013] Preferably, the thickness of the chemical vapor deposited silicon element is 5nm-50nm.
[0014] Preferably, the method for preparing the carbon nanotube array comprises the following steps:
[0015] After carbon elements are deposited on the inner surface of an alumina template by chemical vapor deposition, the alumina template is removed to obtain a carbon nanotube array.
[0016] Preferably, the deposition vacuum degree of the chemical vapor deposition is (0.5-1.5)×10 -4 Pa, the deposition temperature is 600°C-680°C, and the heating rate to the deposition temperature is 5°C / min-10°C / min.
[0017] Preferably, the deposition atmosphere of the chemical vapor deposition is an argon atmosphere.
[0018] Preferably, the carbon element is deposited by introducing acetylene gas.
[0019] Preferably, before removing the alumina template, a platinum support layer is sputtered on the bottom of the alumina template on which the carbon element is deposited.
[0020] Preferably, the sputtering is performed by magnetron sputtering, and the vacuum degree of the magnetron sputtering is (0.5-1.5)×10 -6 Pa, power is 30W-50W, time is 10min-20min.
[0021] Preferably, the magnetron sputtering is performed under an argon atmosphere.
[0022] Preferably, the aluminum oxide template is removed by etching with an aqueous sodium hydroxide solution.
[0023] Preferably, the mass fraction of the sodium hydroxide aqueous solution is 10%-15%.
[0024] A second aspect of the present invention provides a method for preparing the three-dimensional porous negative electrode material according to the aforementioned scheme, comprising the following steps:
[0025] A lithium metal layer is loaded on a carbon-silicon porous material to obtain a three-dimensional porous negative electrode material;
[0026] The lithium metal layer is loaded on the carbon-silicon porous material by electrochemical deposition or melt infusion.
[0027] The method for preparing the three-dimensional porous negative electrode material of the present invention not only offers the advantages of ease of operation and low cost, but also demonstrates excellent efficiency and high efficiency. The method can be implemented in a single step, making the preparation process both fast and convenient, significantly reducing production costs.
[0028] Preferably, the current density of the electrochemical deposition is 0.1 mA cm -2 -0.5mA cm -2 , time is 1h-50h.
[0029] Preferably, the melt infusion amount is 0.026 mg cm -2 -1.5 mg cm -2 .
[0030] Preferably, the thickness of the lithium metal layer is 1 μm-30 μm.
[0031] A third aspect of the present invention provides a creep-type all-solid-state lithium metal battery, comprising a positive electrode, a solid electrolyte, and a negative electrode;
[0032] The positive electrode comprises a positive electrode current collector, a conductive material, a positive electrode solid electrolyte and a positive electrode active material layer;
[0033] The solid electrolyte is selected from polymers, oxides or sulfides;
[0034] The negative electrode includes the three-dimensional porous negative electrode material described in the above scheme.
[0035] The three-dimensional porous anode material proposed in this invention, when applied to solid-state lithium metal batteries, can construct a creep-type all-solid-state lithium metal battery. This creep-type all-solid-state lithium metal battery exhibits high energy density, good charge-discharge cycle stability, and excellent mechanical stability and safety. These properties give it great potential for application in future energy storage systems.
[0036] Preferably, the positive electrode active material is selected from lithium iron phosphate, lithium nickel cobalt manganese oxide or lithium cobalt oxide.
[0037] Preferably, the solid electrolyte is selected from a PEO-based polymer solid electrolyte, an LLZTO solid electrolyte or an LPSCl solid electrolyte.
[0038] In summary, the present invention includes at least one of the following beneficial technical effects:
[0039] 1. The three-dimensional porous anode material provided by the present invention possesses unique structural properties that effectively promote the uniform deposition and stripping of lithium metal within the nanotubes through a creep mechanism, allowing the lithium metal to form a "flowable metal liquid" at the nanoscale. This significantly alleviates the stress problems generated during the charge and discharge process and maintains good interface contact between the electrode and the electrolyte. Furthermore, the carbon-silicon porous material provided by the present invention has extremely high stability to lithium metal, which fundamentally eliminates the formation of a solid electrolyte interface layer, thereby improving the cycle stability and life of the battery.
[0040] 2. The carbon nanotube array structure provided by this invention not only significantly improves the overall conductivity of the electrode material but also exhibits excellent adaptability, effectively adapting to the volume changes experienced by the negative electrode material during charge and discharge cycles. This adaptability ensures the integrity of the electrode structure and reduces mechanical damage caused by volume expansion and contraction, thereby further improving battery performance and reliability.
[0041] 3. The method for preparing the three-dimensional porous negative electrode material of the present invention not only offers the advantages of ease of operation and low cost, but also demonstrates excellent efficiency and high efficiency. This method can be implemented in a single step, making the preparation process both rapid and convenient, significantly reducing production costs.
[0042] 4. The three-dimensional porous anode material proposed in this invention, when applied to solid-state lithium metal batteries, can construct a creep-type all-solid-state lithium metal battery. This creep-type all-solid-state lithium metal battery exhibits high energy density, excellent charge-discharge cycle stability, and outstanding mechanical stability and safety. These properties give it great potential for application in future energy storage systems. DETAILED DESCRIPTION
[0043] Figure 1 This is an SEM image of the carbon-silicon porous material prepared in Example 1;
[0044] Figure 2 This is the mapping diagram of the carbon-silicon porous material prepared in Example 1;
[0045] Figure 3 Graphs showing the electrochemical performance of the creep-type all-solid-state lithium metal battery in Example 1 and the solid-state lithium metal battery in Comparative Example 1;
[0046] Figure 4 1 is a performance comparison chart of the half-cells in Example 1 and Comparative Example 1. DETAILED DESCRIPTION
[0047] The technical solutions in the embodiments of the present invention will be described clearly and completely below. Obviously, the described embodiments are only one embodiment of the present invention, not all embodiments. Based on the embodiments in the present invention, all other embodiments obtained by those of ordinary skill in the art without creative work are within the scope of protection of the present invention. Unless otherwise specified, the raw materials in the embodiments of the present invention were purchased from commercial sources.
[0048] Example 1
[0049] This embodiment provides a three-dimensional porous negative electrode and a creep-type all-solid-state lithium metal battery, specifically including the following solutions:
[0050] A method for preparing a three-dimensional porous negative electrode comprises the following steps:
[0051] (1) Place the alumina template on the sample stage of the chemical vapor deposition equipment and pump the vacuum degree of the reaction chamber to 10 - 4 Pa, argon gas was introduced to stabilize the pressure in the reaction chamber at 5 Torr. The heating system was turned on and the reaction chamber was heated at a rate of 5°C / min to 650°C. After the temperature and pressure stabilized, acetylene gas was introduced at a flow rate of 100 sccm. The deposition time was 30 minutes. After the deposition time was completed, the acetylene gas valve was closed and the carbon nanotube array precursor was obtained after cooling.
[0052] (2) Place the carbon nanotube precursor on the sample stage of the magnetron sputtering equipment, install the platinum target, and pump the vacuum degree of the reaction chamber to 10 -6 Pa, argon gas was introduced to stabilize the pressure in the reaction chamber at 5 mTorr, a DC power supply was turned on with a power of 50 W, the sputtering time was 10 minutes, and the sample was taken out after cooling. Then, 60 g of sodium hydroxide solid was weighed and prepared into 500 mL of sodium hydroxide aqueous solution. The sodium hydroxide aqueous solution was used to etch the alumina template to obtain a carbon nanotube array;
[0053] (3) Place the carbon nanotube array on the sample stage of the atomic layer deposition equipment and pump the vacuum degree of the reaction chamber to 10 - 4 Pa, turn on the heating system, heat the reaction chamber at a heating rate of 5°C / min until the temperature reaches 250°C, then open the SiH4 valve and introduce the precursor into the reaction chamber in pulses through the gas flow controller with a pulse time of 1 second. Close the SiH4 valve and introduce nitrogen to purge the reaction chamber to expel unreacted precursor molecules and reaction by-products from the reaction chamber. The purge time is 20 seconds. Repeat the above deposition cycle until the silicon layer thickness reaches 10nm, thus obtaining a carbon-silicon porous material.
[0054] (4) The carbon-silicon porous material and the lithium metal sheet were used as the electrode and the counter electrode, respectively, to assemble the battery. The lithium metal was deposited on the carbon-silicon porous material by electrochemical deposition. The current density of the electrochemical deposition was 0.1 mA cm -2 , time is 10h, the thickness of the deposited lithium metal layer is 6.25μm, and a three-dimensional porous negative electrode is obtained.
[0055] A method for preparing a creep-type all-solid-state lithium metal battery comprises the following steps:
[0056] Lithium iron phosphate powder, super P, polyethylene oxide, and lithium bis(trifluoromethanesulfonyl)imide were mixed in acetonitrile at a weight ratio of 6:1:2:1 to obtain a lithium iron phosphate slurry, and the obtained lithium iron phosphate slurry was then coated on a carbon-coated aluminum foil and vacuum-dried at 70°C for 12 hours to obtain a lithium iron phosphate positive electrode material;
[0057] The positive electrode, LPSCl solid electrolyte and three-dimensional porous negative electrode are assembled into a battery to obtain a creep-type all-solid-state lithium metal battery.
[0058] The carbon silicon porous material in Example 1 was tested by SEM and Mapping. The test results are as follows: Figure 1 and Figure 2 As shown, Figure 1 This is the SEM image of the carbon-silicon porous material prepared in Example 1. Figure 2 This is the mapping diagram of the carbon silicon porous material prepared in Example 1. Figure 1It can be seen that the nanotubes in the carbon-silicon porous material prepared in Example 1 are vertically arranged and have a diameter of 100 nm. Figure 2 It can be seen that Si elements are evenly distributed on the surface of the nanotubes.
[0059] Example 2
[0060] This embodiment provides a three-dimensional porous negative electrode and a creep-type all-solid-state lithium metal battery, specifically including the following solutions:
[0061] A method for preparing a three-dimensional porous negative electrode comprises the following steps:
[0062] (1) Place the alumina template on the sample stage of the chemical vapor deposition equipment and pump the vacuum of the reaction chamber to 1.5×10 -4 Pa, argon was introduced to stabilize the pressure in the reaction chamber at 5 Torr. The heating system was turned on and the reaction chamber was heated at a rate of 10°C / min to 680°C. After the temperature and pressure stabilized, acetylene gas was introduced at a flow rate of 150 sccm. The deposition time was 35 minutes. After the deposition time was complete, the acetylene gas valve was closed and the carbon nanotube array precursor was obtained after cooling.
[0063] (2) Place the carbon nanotube precursor on the sample stage of the magnetron sputtering equipment, install the platinum target, and pump the vacuum degree of the reaction chamber to 10 -6 Pa, argon was introduced to stabilize the pressure in the reaction chamber at 5 mTorr. A DC power supply was turned on at 60 W, and the sputtering time was 15 minutes. After cooling, the sample was removed. 60 g of solid sodium hydroxide was weighed and mixed into 500 mL of a sodium hydroxide aqueous solution. The sodium hydroxide aqueous solution was used to etch the alumina template to obtain a carbon nanotube array.
[0064] (3) Place the carbon nanotube array on the sample stage of the atomic layer deposition equipment and pump the vacuum degree of the reaction chamber to 1.5×10 -4 Pa, turn on the heating system, and heat the reaction chamber at a heating rate of 10°C / min until the temperature reaches 300°C. Then, open the SiH4 valve and introduce the precursor into the reaction chamber in pulses through the gas flow controller. The pulse time is 1.5 seconds. Close the SiH4 valve and introduce nitrogen to purge the reaction chamber to remove unreacted precursor molecules and reaction byproducts. The purge time is 25 seconds. Repeat the above deposition cycle until the silicon layer thickness reaches 10nm, thus obtaining a carbon-silicon porous material.
[0065] (4) The carbon-silicon porous material and the lithium metal sheet were used as the electrode and the counter electrode, respectively, to assemble the battery. The lithium metal was deposited on the carbon-silicon porous material by electrochemical deposition. The current density of the electrochemical deposition was 0.5 mA cm -2, time is 4h, the thickness of the deposited lithium metal layer is 12.5μm, and a three-dimensional porous negative electrode is obtained.
[0066] A method for preparing a creep-type all-solid-state lithium metal battery comprises the following steps:
[0067] Lithium iron phosphate powder, super P, polyethylene oxide, and lithium bis(trifluoromethanesulfonyl)imide were mixed in acetonitrile at a weight ratio of 6:1:2:1 to obtain a lithium iron phosphate slurry, and the obtained lithium iron phosphate slurry was then coated on a carbon-coated aluminum foil and vacuum-dried at 70°C for 12 hours to obtain a lithium iron phosphate positive electrode material;
[0068] The positive electrode, LPSCl solid electrolyte and three-dimensional porous negative electrode are assembled into a battery to obtain a creep-type all-solid-state lithium metal battery.
[0069] Example 3
[0070] This embodiment provides a three-dimensional porous negative electrode and a creep-type all-solid-state lithium metal battery, specifically including the following solutions:
[0071] A method for preparing a three-dimensional porous negative electrode comprises the following steps:
[0072] (1) Place the alumina template on the sample stage of the chemical vapor deposition equipment and pump the vacuum of the reaction chamber to 0.5×10 -4 Pa, argon was introduced to stabilize the pressure in the reaction chamber at 5 Torr. The heating system was turned on and the reaction chamber was heated at a rate of 7°C / min to 600°C. After the temperature and pressure stabilized, acetylene gas was introduced at a flow rate of 50 sccm. The deposition time was 25 minutes. After the deposition time was completed, the acetylene gas valve was closed and the carbon nanotube array precursor was obtained after cooling.
[0073] (2) Place the carbon nanotube precursor on the sample stage of the magnetron sputtering equipment, install the platinum target, and pump the vacuum degree of the reaction chamber to 10 -6 Pa, argon gas was introduced to stabilize the pressure in the reaction chamber at 5 mTorr, a DC power supply was turned on with a power of 40 W, the sputtering time was 15 minutes, and the sample was taken out after cooling. Then, 60 g of sodium hydroxide solid was weighed and prepared into 500 mL of sodium hydroxide aqueous solution. The sodium hydroxide aqueous solution was used to etch the alumina template to obtain a carbon nanotube array;
[0074] (3) Place the carbon nanotube array on the sample stage of the atomic layer deposition equipment and pump the vacuum of the reaction chamber to 0.5×10 -4Pa, turn on the heating system, and heat the reaction chamber at a heating rate of 7°C / min until the temperature reaches 200°C. Then, open the SiH4 valve and introduce the precursor into the reaction chamber in pulses through the gas flow controller. The pulse time is 0.5s. Close the SiH4 valve and introduce nitrogen to purge the reaction chamber to remove unreacted precursor molecules and reaction byproducts. The purge time is 15s. Repeat the above deposition cycle until the silicon layer thickness reaches 5nm, thus obtaining a carbon-silicon porous material.
[0075] (4) The carbon-silicon porous material and the lithium metal sheet were used as the electrode and the counter electrode, respectively, to assemble the battery. The lithium metal was deposited on the carbon-silicon porous material by electrochemical deposition. The current density of the electrochemical deposition was 0.1 mA cm -2 , time is 50h, the thickness of the deposited lithium metal layer is 30μm, and a three-dimensional porous negative electrode is obtained.
[0076] A method for preparing a creep-type all-solid-state lithium metal battery comprises the following steps:
[0077] Lithium iron phosphate powder, super P, polyethylene oxide, and lithium bis(trifluoromethanesulfonyl)imide were mixed in acetonitrile at a weight ratio of 6:1:2:1 to obtain a lithium iron phosphate slurry, and the obtained lithium iron phosphate slurry was then coated on a carbon-coated aluminum foil and vacuum-dried at 70°C for 12 hours to obtain a lithium iron phosphate positive electrode material;
[0078] The positive electrode, LPSCl solid electrolyte and three-dimensional porous negative electrode are assembled into a battery to obtain a creep-type all-solid-state lithium metal battery.
[0079] Example 4
[0080] This embodiment provides a three-dimensional porous negative electrode and a creep-type all-solid-state lithium metal battery, specifically including the following solutions:
[0081] A method for preparing a three-dimensional porous negative electrode comprises the following steps:
[0082] (1) Place the alumina template on the sample stage of the chemical vapor deposition equipment and pump the vacuum of the reaction chamber to 0.5×10 -4 Pa, argon was introduced to stabilize the pressure in the reaction chamber at 5 Torr. The heating system was turned on and the reaction chamber was heated at a rate of 7°C / min to 600°C. After the temperature and pressure stabilized, acetylene gas was introduced at a flow rate of 50 sccm. The deposition time was 25 minutes. After the deposition time was completed, the acetylene gas valve was closed and the carbon nanotube array precursor was obtained after cooling.
[0083] (2) Place the carbon nanotube precursor on the sample stage of the magnetron sputtering equipment, install the platinum target, and pump the vacuum degree of the reaction chamber to 10 -6Pa, argon gas was introduced to stabilize the pressure in the reaction chamber at 5 mTorr, a DC power supply was turned on with a power of 50 W, the sputtering time was 10 minutes, and the sample was taken out after cooling. Then, 60 g of sodium hydroxide solid was weighed and prepared into 500 mL of sodium hydroxide aqueous solution. The sodium hydroxide aqueous solution was used to etch the alumina template to obtain a carbon nanotube array;
[0084] (3) Place the carbon nanotube array on the sample stage of the atomic layer deposition equipment and pump the vacuum of the reaction chamber to 0.5×10 -4 Pa, turn on the heating system, and heat the reaction chamber at a heating rate of 7°C / min until the temperature reaches 200°C. Then, open the SiH4 valve and introduce the precursor into the reaction chamber in pulses through the gas flow controller. The pulse time is 0.5s. Close the SiH4 valve and introduce nitrogen to purge the reaction chamber to remove unreacted precursor molecules and reaction byproducts. The purge time is 15s. Repeat the above deposition cycle until the silicon layer thickness reaches 5nm, thus obtaining a carbon-silicon porous material.
[0085] (4) The carbon-silicon porous material and the lithium metal sheet are used as the electrode and the counter electrode, respectively, to assemble the battery. The infusion amount of the melt infusion is 1 mg cm -2 , and a three-dimensional porous negative electrode was obtained.
[0086] A method for preparing a creep-type all-solid-state lithium metal battery comprises the following steps:
[0087] Lithium iron phosphate powder, super P, polyethylene oxide, and lithium bis(trifluoromethanesulfonyl)imide were mixed in acetonitrile at a weight ratio of 6:1:2:1 to obtain a lithium iron phosphate slurry, and the obtained lithium iron phosphate slurry was then coated on a carbon-coated aluminum foil and vacuum-dried at 70°C for 12 hours to obtain a lithium iron phosphate positive electrode material;
[0088] The positive electrode, LPSCl solid electrolyte and three-dimensional porous negative electrode are assembled into a battery to obtain a creep-type all-solid-state lithium metal battery.
[0089] Comparative Example 1
[0090] This comparative example provides a three-dimensional porous negative electrode and a solid-state lithium metal battery, specifically including the following solutions:
[0091] A method for preparing a three-dimensional porous negative electrode comprises the following steps:
[0092] (1) Place the alumina template on the sample stage of the chemical vapor deposition equipment and pump the vacuum degree of the reaction chamber to 10 - 4Pa, argon gas was introduced to stabilize the pressure in the reaction chamber at 5 Torr, the heating system was turned on, and the reaction chamber was heated at a heating rate of 5 ° C / min to reach a temperature of 650 ° C. After the temperature and pressure were stabilized, acetylene gas was introduced at an acetylene flow rate of 100 sccm. The acetylene gas was introduced and the deposition time was 30 min. After the deposition time was completed, the acetylene gas valve was closed and the carbon nanotube precursor was obtained after cooling;
[0093] (2) Place the carbon nanotube precursor on the sample stage of the magnetron sputtering equipment, install the platinum target, and pump the vacuum degree of the reaction chamber to 10 -6 Pa, argon gas was introduced to stabilize the pressure in the reaction chamber at 5mTorr, a DC power supply was turned on with a power of 50W, the sputtering time was 10 minutes, and the sample was taken out after cooling. Then 60g of sodium hydroxide solid was weighed and prepared into 500mL of sodium hydroxide aqueous solution, and then the sodium hydroxide aqueous solution was used to etch the alumina template to obtain a carbon nanotube array;
[0094] (3) The carbon nanotube array and lithium metal sheet were used as electrodes and counter electrodes, respectively, to assemble the battery. Lithium metal was deposited on the carbon nanotube precursor by electrochemical deposition. The current density of electrochemical deposition was 0.1 mA cm -2 , time is 10h, the thickness of the deposited lithium metal layer is 6.25μm, and a three-dimensional porous negative electrode is obtained.
[0095] A method for preparing a solid-state lithium metal battery comprises the following steps:
[0096] Lithium iron phosphate powder, super P, polyethylene oxide, and lithium bis(trifluoromethanesulfonyl)imide were mixed in acetonitrile at a weight ratio of 6:1:2:1 to obtain a lithium iron phosphate slurry, and the obtained lithium iron phosphate slurry was then coated on a carbon-coated aluminum foil and vacuum-dried at 70°C for 12 hours to obtain a lithium iron phosphate positive electrode material;
[0097] The positive electrode, LPSCl solid electrolyte and three-dimensional porous negative electrode are assembled into a battery to obtain a solid-state lithium metal battery.
[0098] The electrochemical performance of the creep-type all-solid-state lithium metal battery in Example 1 and the solid-state lithium metal battery in Comparative Example 1 were tested, and the results were as follows: Figure 3 As shown, Figure 3 The electrochemical performance diagram of the creep-type all-solid-state lithium metal battery in Example 1 and the solid-state lithium metal battery in Comparative Example 1 is shown in FIG. Figure 3 It can be seen that when the creep-type all-solid-state lithium metal battery provided in Example 1 is subjected to charge and discharge performance testing at a rate of 1C, it can be stably cycled 200 times with a capacity decay rate of 0.18%, while the capacity decay of the solid-state lithium metal battery in Comparative Example 1 is fast and the cycle performance is poor.
[0099] The two three-dimensional porous negative electrodes in Example 1 were used as the positive electrode and negative electrode respectively, and the LPSCl solid electrolyte was used to assemble the half-cell of Example 1. The two three-dimensional porous negative electrodes in Comparative Example 1 were used as the positive electrode and negative electrode respectively, and the LPSCl solid electrolyte was used to assemble the half-cell of Comparative Example 1. The performance of the half-cells in Example 1 and Comparative Example 1 was compared, and the results were as follows. Figure 4 As shown, Figure 4 The performance comparison diagram of the half-cell in Example 1 and Comparative Example 1 is shown in FIG. Figure 4 It can be seen that at 0.2 mAh·cm -1 Under the cycle conditions of , the cycle performance of the half-cell in Example 1 is 380h, and the cycle performance of the half-cell in Comparative Example 1 is 100h.
[0100] The above are all preferred embodiments of the present invention, and are not intended to limit the scope of protection of the present invention. Therefore, any equivalent changes made based on the structure, shape, and principle of the present invention should be included in the scope of protection of the present invention.
Claims
1. A three-dimensional porous negative electrode material, characterized in that: The carbon-silicon porous material comprises a lithium metal layer provided on the carbon-silicon porous material; The carbon-silicon porous material includes an electronic conductor and an ion conductor. The electronic conductor is a carbon nanotube array, and the ion conductor is a silicon element deposition layer.
2. The three-dimensional porous negative electrode material according to claim 1, characterized in that The preparation method of the carbon-silicon porous material comprises the following steps: Silicon elements are deposited on the surface of the carbon nanotube array by atomic layer deposition to obtain a carbon-silicon porous material.
3. The three-dimensional porous negative electrode material according to claim 2, characterized in that: The deposition vacuum degree of the atomic layer deposition is (0.5-1.5)×10 -4 Pa, the deposition temperature is 200°C-300°C, and the heating rate to the deposition temperature is 5°C / min-10°C / min.
4. The three-dimensional porous negative electrode material according to claim 2, characterized in that: The silicon element is deposited by introducing SiH4 silicon precursor in pulse form, the pulse time is 0.5s-1.5s, and the purge time is 15s-25s; and / or The thickness of the chemical vapor deposited silicon element is 5nm-50nm.
5. The three-dimensional porous negative electrode material according to claim 2, characterized in that: The method for preparing the carbon nanotube array comprises the following steps: After carbon elements are deposited on the inner surface of an alumina template by chemical vapor deposition, the alumina template is removed to obtain a carbon nanotube array.
6. The three-dimensional porous negative electrode material according to claim 5, characterized in that: The deposition vacuum degree of the chemical vapor deposition is (0.5-1.5)×10 -4 Pa, the deposition temperature is 600°C-680°C, and the heating rate to the deposition temperature is 5°C / min-10°C / min; and / or The deposition atmosphere of the chemical vapor deposition is an argon atmosphere; and / or The carbon element is deposited by introducing acetylene gas; and / or The flow rate of the acetylene gas is 50 sccm-150 sccm, and the time is 25 min-35 min.
7. The method for preparing the three-dimensional porous negative electrode material according to any one of claims 1 to 6, characterized in that: The following steps are involved: A lithium metal layer is loaded on a carbon-silicon porous material to obtain a three-dimensional porous negative electrode material; The lithium metal layer is loaded on the carbon-silicon porous material by electrochemical deposition or melt infusion.
8. The method for preparing a three-dimensional porous negative electrode material according to claim 7, wherein: The current density of the electrochemical deposition was 0.1 mA cm -2 -0.5mA cm -2 , lasting 1 hour to 50 hours; and / or The infusion amount of the melt infusion was 0.026 mg cm -2 -1.5 mg cm -2 .
9. The method for preparing a three-dimensional porous negative electrode material according to claim 7, wherein: The thickness of the lithium metal layer is 1 μm-30 μm.
10. A creep-type all-solid-state lithium metal battery, characterized in that: including a positive electrode, a solid electrolyte, and a negative electrode; The positive electrode comprises a positive electrode current collector, a conductive material, a positive electrode solid electrolyte and a positive electrode active material layer; The solid electrolyte is selected from polymers, oxides or sulfides; The negative electrode comprises the three-dimensional porous negative electrode material according to any one of claims 1 to 6 or the three-dimensional porous negative electrode material prepared by the preparation method according to any one of claims 7 to 9.