Metal ion battery electrode material and preparation method and application thereof

Abstract

The application belongs to the field of metal ion battery electrode materials, and particularly relates to a metal ion battery electrode material and a preparation method and application thereof. The preparation method of the battery electrode material comprises the following steps: (1) washing plant leaf solid waste with water, rapidly dehydrating the plant leaf solid waste in a microwave electromagnetic field, crushing the plant leaf solid waste, and obtaining an electrode material carbon precursor; (2) embedding the electrode material carbon precursor in a conductive powder bed of an embedded electrode, and connecting two ends of the electrode to a pulse power supply; (3) setting pulse power supply parameters, performing superfast high-temperature heat treatment under the protection of an inert gas, cooling, and sieving, and the battery electrode material is obtained. The application simplifies the process, improves the preparation efficiency of the material, and can control the phase composition and physical and chemical properties of the product by controlling the related parameters of the pulse power supply, and can also realize multi-stage adjustment of the graphite interlayer spacing of the metal ion battery electrode material.

Description

TECHNICAL FIELD

[0001] The application belongs to the field of metal ion battery electrode materials, and particularly relates to a metal ion battery electrode material and a preparation method and application thereof. BACKGROUND

[0002] Due to the shortage of fossil resources, the development and application of carbon-containing materials are greatly limited. Forestry biomass, agricultural waste, aquatic plants, energy plants and other biomass resources are renewable resources and become substitutes for fossil resource products. Most of the biomass resources contain rich carbon, and therefore, the preparation of electrode materials using renewable biomass resources as raw materials has become the mainstream of the energy storage industry.

[0003] Chinese patent application CN110719891A discloses a sodium ion battery hard carbon negative material based on biomass and a preparation method and application thereof. The method comprises the following steps: washing and drying the biomass material, heating the biomass material at 100-800 DEG C under an oxygen-free atmosphere for 1-24 hours to obtain a carbon precursor; crushing the obtained carbon precursor and immersing it in a permanganate solution to oxidize the carbon material and generate more sodium storage sites; drying and sieving the treated carbon precursor, and then performing secondary sintering under an inert atmosphere at 800-2500 DEG C for 0.5-48 hours; then washing the product with acid solution, rinsing with clean water until PH=7, and drying to obtain the final product. However, this method increases the permanganate oxidation treatment process and the secondary sintering process in the preparation process, increases the active sites on the surface of the material by pre-carbonization and permanganate oxidation of the surface of the carbon material, to make up for the decrease in the electrical conductivity caused by the destruction of the natural microstructure of the plant raw material, the process is complex, the time and energy consumption are huge, impurities are easily introduced, the phase composition is complex, and the application range of the method is small.

[0004] Chinese invention patent application CN106299365A discloses a biomass hard carbon negative electrode material for sodium ion battery, a preparation method and a sodium ion battery. The biomass hard carbon negative electrode material is prepared by the following method: 1) crushing the biomass raw material to obtain precursor particles; 2) under a protective atmosphere, the precursor particles are heated to 400-600℃ for 1.5-2.5h, then the furnace is cooled to room temperature, and then heated to 800-1600℃ for 2-5h, and then cooled to obtain an intermediate product; 3) the intermediate product is soaked in an alkali solution, taken out and soaked in an acid solution, then washed with water to neutral, and dried to obtain a purified product; 4) the purified product is subjected to microwave vacuum activation at a power of 1000-2000W for 3-15s. However, this method increases the alkali and acid treatment process to remove impurities in plant materials, but the use of alkali and acid treatment also destroys the natural microstructure of plant materials, reduces the conductivity, and increases the microwave treatment process to increase the conductivity, which is complex, time-consuming and energy-consuming, and cannot accurately control the phase composition and physical and chemical properties of the product, so the application range of this method is small.

[0005] Chinese invention patent application CN109830376A discloses a method for preparing a metal oxide and biomass charcoal composite electrode material assisted by an external electromagnetic field. The method mixes bamboo charcoal raw material treated by alkali-acid two-step activation with a soluble metal salt; then puts the mixture into a reaction kettle with an external magnetic field and electric field for 6-24h hydrothermal reaction; dries the hydrothermal reaction product and puts it into an annealing furnace; and washes and dries the final product to obtain an electrode material. However, long-time heating in this method destroys the natural microstructure of plant raw materials that is beneficial to the deintercalation of aluminum ions, and the electrical properties of the material are reduced. At the same time, the long heating and holding time makes the preparation efficiency low and the energy consumption huge.

[0006] Therefore, it is necessary to develop a metal ion battery electrode material and a preparation method thereof, which are simple in preparation process, low in raw material cost, green, energy-saving and efficient. SUMMARY

[0007] In view of the above problems that the natural microstructure of plant raw materials is easily destroyed, the preparation process is complex, impurities are easily introduced, and the phase composition and physical and chemical properties of the product cannot be accurately controlled, the present application provides a metal ion battery electrode material, a preparation method and application thereof. The preparation method comprises: using plant leaf solid waste as raw material, and realizing ultra-fast dehydration by electromagnetic field heating technology to effectively reduce energy consumption; then filling the dried raw material in a conductive powder bed with an embedded electrode, using a high-precision multi-waveform adjustable pulse power to pass current and generate Joule heat, realizing high-controllable ultra-fast heating of the electrode raw material, and preparing a multi-level heterogeneous structure electrode material with good conductivity and good metal ion storage and deintercalation ability in a short time.

[0008] To achieve the above object, the present application provides the following technical solutions.

[0009] A preparation method of a metal ion battery electrode material, comprising the following steps:

[0010] (1) washing, dewatering, and crushing plant leaf solid waste to obtain an electrode material carbon precursor;

[0011] (2) embedding the electrode material carbon precursor in a conductive powder bed of an embedded electrode, and connecting both ends of the electrode to a pulse power supply;

[0012] (3) setting pulse power supply parameters, high-temperature heat treatment under inert gas protection, cooling, and sieving.

[0013] Preferably, the plant leaf solid waste in step (1) comprises one or more of branches and leaves of grass and trees, waste tea leaves (including old tea and tea residue after brewing), and aquatic plants.

[0014] Preferably, the dewatering treatment in step (1) is performed in a microwave electromagnetic field environment, and the frequency of the electromagnetic field is 915 MHz-5.8 GHz; the dewatering treatment uses a multimode microwave cavity, the unit mass feed-in power intensity is 500-2000 W / Kg, and the heating time is 2-4 min.

[0015] Preferably, the particle size of the conductive powder in the conductive powder bed before embedding the carbon precursor in step (2) is greater than 100 μm or less than 10 μm. The particle size of the conductive powder should be much larger or much smaller than the particle size of the crushed carbon precursor, which helps to separate the two.

[0016] Preferably, the pulse power supply parameters in step (3) include pulse current waveform, pulse current peak value, and pulse frequency; the number of high-temperature heat treatments is 2 or more, and the temperature of the heat treatment is 900-3200℃.

[0017] Further preferably, the pulse current waveform is selected from one or more of rectangular wave and bell-shaped wave, sharp wave, and step wave; the pulse current peak value is 10-500 A; the pulse frequency is 10-100 Hz; and the number of high-temperature heat treatments is 3, wherein the first pulse current waveform is sharp wave or bell-shaped wave, the second pulse current waveform is rectangular wave, and the third pulse current waveform is step wave.

[0018] Further preferably, the first pulse current peak value is 10-50 A, the pulse frequency is 50-100 Hz, the heating time is 30-50 s, and the heating temperature is 900-1200 DEG C; the second pulse peak current is 50-200 A, the pulse frequency is 10-50 Hz, the heating time is 40-60 s, and the heating temperature is 1500-2000 DEG C; the third pulse peak current is 200-500 A, the pulse frequency is 10-50 Hz, the heating time is 10-200 s, and the heating temperature is 2000-3200 DEG C.

[0019] Preferably, the screen mesh size in the sieving in step (3) is 150-1800 mesh.

[0020] The application also relates to the metal ion battery electrode material prepared by the preparation method.

[0021] Preferably, the interlayer spacing of the electrode material is 0.34-0.42 nm, and the particle size D50 is 10-100 mu m.

[0022] The application also relates to the application of the electrode material prepared by the preparation method in a metal ion battery negative electrode.

[0023] Preferably, the metal ion battery includes an aluminum ion battery, a lithium ion battery and a sodium ion battery.

[0024] Compared with the prior art, the application has the following beneficial effects:

[0025] (1) The electromagnetic field heating technology is used to realize rapid dehydration of raw materials, shorten the drying and dehydration time, effectively reduce the energy consumption, and improve the specific surface area while maintaining the natural microstructure of the biomass material; the high-precision multi-waveform adjustable pulse current is used to realize ultrafast high-temperature heating, rapidly prepare the battery electrode material, and maximize the retention of the original biomass heterostructure of the plant leaf raw material; and in the rapid heating process, the impurities and organic matter pyrolysis can form a multi-level heterogeneous structure on the material matrix, effectively improve the specific surface area, and be beneficial to the deintercalation of metal ions.

[0026] (2) The process is simplified, the material preparation efficiency is improved, and the energy consumption is greatly reduced; meanwhile, the control of the pulse current related parameters can realize the control of the phase composition and the physical and chemical properties of the product, finally realize the multi-level regulation of the graphite interlayer spacing of the metal ion battery electrode material, and then design and regulate the physical and chemical properties of the material.

[0027] (3) The plant leaf solid waste raw material has a wide source, compared with the prior art, no additives or surface modification is needed, the process complexity and the impurity introduction probability are reduced, the preparation cost is reduced, and the limitation on the raw material is small.

[0028] (4) Due to the limitation of raw materials is small, and in the process of realizing the control of physical and chemical properties, so that the method can be applied to the preparation of hard carbon, soft carbon and composite carbon materials, the application range is wider. BRIEF DESCRIPTION OF DRAWINGS

[0029] Figure 1 is the XRD pattern of the electrode material prepared in Example 1;

[0030] Figure 2 is the XRD pattern of the electrode material prepared in Example 2;

[0031] Figure 3 is the SEM pattern of the electrode material prepared in Example 1;

[0032] Figure 4 is the SEM pattern of the electrode material prepared in Example 2. DETAILED DESCRIPTION

[0033] The technical solutions in the embodiments of the application are further described in detail, and the described embodiments are only a part of the application, which are used to explain the application, but not to limit the application, so the other embodiments obtained by other skilled persons in the art without creative labor, all belong to the protection scope of the application.

[0034] Polytetrafluoroethylene (PTFE) emulsion, purchased from Keluode Chemical Technology Co., Ltd.;

[0035] The following reagents not specifically described are conventional reagents, which are commercially available.

[0036] Example 1

[0037] 1. A metal ion battery electrode material, the preparation method is as follows:

[0038] (1) Wash the branches and leaves of trees and plants with deionized water, and place them in a multimode microwave cavity, and place the cavity in the center position of the radio frequency cavity;

[0039] (2) Set the radio frequency to 915MHz, the unit mass feed-in power to 2000W / Kg, and the heating time to 3min, and carry out electromagnetic field rapid dehydration;

[0040] (3) Crush the dehydrated and dried raw materials to obtain an electrode material carbon precursor;

[0041] (4) Fill the carbon precursor in the conductive powder bed of the built-in electrode, and the particle size of the conductive powder is 126μm; connect the two ends of the electrode to the pulse power supply;

[0042] (5) set the output current to 40A, the pulse frequency to 80Hz, the current waveform to a sharp wave, the heating time to 40s, and the temperature to 1000℃ to stop power supply, so that impurities are decomposed and volatilized; the second time, set the peak current to 50A, the pulse frequency to 10Hz, the current waveform to a rectangular wave, the heating time to 60s, and the heating temperature to 1500℃, so that the difficult-to-decompose impurities are further decomposed and volatilized; the third time, set the peak current to 200A, the pulse frequency to 40Hz, the current waveform to a ladder wave, and the heating time to 200s; and the heating temperature to 2500℃;

[0043] (6) After cooling, the powder in the powder bed is taken out and sieved using a 150-mesh sieve to obtain a metal ion battery electrode material with a multi-level heterogeneous structure.

[0044] The XRD spectrum of the electrode material is shown in Figure 1 , the interlayer spacing is 0.382nm, the particle size D50 is about 49.5μm, the specific surface area is 30m 2 / g, and the microstructure is shown in Figure 3 . It can be observed that the material has a multi-level heterogeneous structure that is beneficial to the deintercalation of metal ions. The unit energy consumption of the entire high-temperature conversion process is only 27MJ / kg.

[0045] 2. Preparation of a metal ion battery:

[0046] The above electrode material, conductive carbon black and polytetrafluoroethylene (PTFE) emulsion are uniformly mixed in a mass ratio of 90:5:1, coated on an aluminum sheet with a thickness of 0.1mm, and a metal ion battery positive electrode is prepared. Pure aluminum sheet as negative electrode, anhydrous aluminum chloride and 1-ethyl-3-methylimidazole chloride are prepared into ion liquid in a molar ratio of 1.7:1 in an argon environment glove box, and assembled into a metal ion battery.

[0047] Example 2

[0048] 1. A metal ion battery electrode material, the preparation method is as follows:

[0049] (1) The waste tea leaves are washed with deionized water and placed in a multi-mode microwave cavity, and the cavity is placed at the center position of the radio frequency cavity;

[0050] (2) Set the radio frequency to 2.4GHz, the unit mass feed-in power to 500W / Kg, and the heating time to 3min, and perform electromagnetic field rapid dehydration;

[0051] (3) The dehydrated and dried raw material is crushed to obtain an electrode material carbon precursor;

[0052] (4) The carbon precursor is filled in a conductive powder bed with an embedded electrode, the particle size of the conductive powder is 126μm, and the two ends of the electrode are connected to a pulse power supply.

[0053] (5) Set the output current to 50A, the pulse frequency to 100Hz, the current waveform to clock wave, the heating time to 30s, and the temperature to 1200℃ to stop power supply to decompose and volatilize impurities; the second time power supply is set to peak current of 200A, pulse frequency of 50Hz, current waveform of rectangular wave, heating time of 40s, and heating temperature of 2000℃ to further decompose and volatilize difficult-to-decompose impurities; the third time power supply is set to peak current of 500A, pulse frequency of 50Hz, current waveform of step wave, heating time of 140s, and heating temperature of 3200℃;

[0054] (6) After cooling, the powder in the powder bed is taken out and sieved using a 150 mesh sieve to obtain a metal ion battery electrode material with a multi-level heterogeneous structure.

[0055] The XRD spectrum of the above electrode material is shown in Figure 2 , the interlayer spacing is 0.389nm, the specific surface area is 28m 2 / g, the particle size D50 is about 63.1μm, and the microstructure is shown in Figure 4 , and the multi-level heterogeneous structure beneficial to the deintercalation of metal ions can be observed; the unit energy consumption of the whole high-temperature conversion process is only 35MJ / kg.

[0056] 2. The preparation method of the metal ion battery is consistent with example 1.

[0057] Example 3

[0058] 1. A metal ion battery electrode material, the preparation method is as follows:

[0059] (1) Wash the waste tea leaves with deionized water, and place them in a multi-mode microwave cavity, and place the cavity at the center position of the radio frequency cavity;

[0060] (2) Set the radio frequency to 5.8GHz, the unit mass feed-in power to 800W / Kg, and the heating time to 2min to perform electromagnetic field rapid dehydration;

[0061] (3) Crush the dehydrated and dried raw materials to obtain an electrode material carbon precursor;

[0062] (4) Fill the carbon precursor into the conductive powder bed with built-in electrodes, and the particle size of the conductive powder is 126μm; connect the two ends of the electrode to the pulse power supply;

[0063] (5) the output current is set to 10 A, the pulse frequency is 50 Hz, the current waveform is a sharp wave, the heating time is 50 s, the temperature reaches 900 DEG C to stop power supply, and the impurities are decomposed and volatilized; the second power supply is set to a peak current of 110 A, a pulse frequency of 30 Hz, a current waveform of a rectangular wave, a heating time of 50 s, and a heating temperature of 1600 DEG C, so that the difficult-to-decompose impurities are further decomposed and volatilized; the third power supply is set to a peak current of 200 A, a pulse frequency of 10 Hz, a current waveform of a ladder wave, a heating time of 10 s, and a heating temperature of 2000 DEG C;

[0064] (6) After cooling, the powder in the powder bed is taken out, sieved using a 150-mesh sieve, and a metal ion battery electrode material with a multi-level heterogeneous structure is prepared.

[0065] The interlayer spacing of the above electrode material is 0.41 nm, the particle size D50 is 53.6 μm, the specific surface area is 26 m 2 / g, and the unit energy consumption of the entire high-temperature conversion process is only 20 MJ / kg.

[0066] 2. The preparation method of the metal ion battery is consistent with example 1.

[0067] Comparative example 1

[0068] 1. A metal ion battery electrode material, the preparation method is as follows:

[0069] (1) The branches and leaves of trees and plants are washed with deionized water and dried in a 60 DEG C oven for 10 h;

[0070] (2) The dried raw material is crushed to obtain a carbon precursor;

[0071] (3) The carbon precursor is placed in a tube furnace, heated to 400 DEG C at 3 DEG C / min under argon atmosphere, and then heated to 2000 DEG C at 5 DEG C / min for 3 h, and then the material is taken out;

[0072] (4) The material is cleaned with 0.5 mol / L hydrochloric acid solution to remove impurities, and then washed with clean water until neutral;

[0073] (5) Dried in a 90 DEG C oven for 6 h to obtain the electrode material.

[0074] The particle size D50 of the electrode material is about 26.4 μm, and the specific surface area is 12 m 2 / g.

[0075] 2. The preparation of the metal ion battery is consistent with example 1.

[0076] Comparative example 2

[0077] 1. A metal ion battery electrode material, the preparation method is as follows:

[0078] (1) The branches and leaves of grass and trees are washed with deionized water and placed in a multimode microwave cavity, and the cavity is placed at the center of the radio frequency cavity;

[0079] (2) The radio frequency is set to 915MHz, the unit mass feed-in power is 2000W / g, and the heating time is 3min, and the electromagnetic field rapid dehydration is carried out;

[0080] (3) The dehydrated and dried raw materials are crushed to obtain the electrode material carbon precursor;

[0081] (4) The carbon precursor is filled in the conductive powder bed with built-in electrodes, the particle size of the conductive powder is 126μm, and the two ends of the electrode are connected to the pulse power supply;

[0082] (5) The output current is set to 40A, the pulse frequency is 80Hz, the current waveform is sharp wave, the heating time is 40s, the temperature reaches 1000℃, and the power supply is stopped, so that the impurities are decomposed and volatilized; The peak current is set to 200A, the pulse frequency is 40Hz, the current waveform is step wave, the heating time is 200s; the heating temperature is 2500℃;

[0083] (6) After cooling, the powder in the powder bed is taken out, sieved with a 150 mesh sieve, and the metal ion battery electrode material is prepared.

[0084] The particle size D50 of the electrode material is about 26.4μm, and the specific surface area is 21m 2 / g

[0085] 2. The preparation method of the metal ion battery is consistent with example 1.

[0086] Comparative example 3

[0087] 1. A metal ion battery electrode material, the preparation method is as follows:

[0088] (1) The branches and leaves of grass and trees are washed with deionized water and placed in a multimode microwave cavity, and the cavity is placed at the center of the radio frequency cavity;

[0089] (2) The radio frequency is set to 915MHz, the unit mass feed-in power is 2000W / Kg, and the heating time is 3min, and the rapid dehydration is carried out;

[0090] (3) The dehydrated and dried raw materials are crushed to obtain the electrode material carbon precursor,;

[0091] (4) The carbon precursor is filled in the conductive powder bed with built-in electrodes, the particle size of the conductive powder is 126μm, and the two ends of the electrode are connected to the pulse power supply;

[0092] (5) the output current is set to 40 A, the pulse frequency is 80 Hz, the current waveform is a step wave, the heating time is 40 s, the temperature reaches 1000°C, and the power supply is stopped to make the impurities decompose and volatilize; the second time of power supply is set to a peak current of 50 A, a pulse frequency of 10 Hz, a square wave current waveform, a heating time of 60 s, and a heating temperature of 1500°C to make the difficult-to-decompose impurities further decompose and volatilize; the third time of power supply is set to a peak current of 200 A, a pulse frequency of 40 Hz, a sharp wave current waveform, a heating time of 200 s, and a heating temperature of 2500°C;

[0093] (6) After cooling, the powder in the powder bed is taken out and sieved using a 150-mesh sieve to obtain the metal ion battery electrode material.

[0094] The particle size D50 of the electrode material is about 26.4 μm, the specific surface area is 23 m 2 / g

[0095] 2. The preparation method of the aluminum ion battery is consistent with example 1.

[0096] Effect test electrical performance detection

[0097] The metal ion battery obtained above is subjected to electrochemical performance test. The electrochemical test is performed on a MACCOR 4200 tester, the voltage range of charging and discharging is 0.5-2.5 V, the current density of charging and discharging is 100 mA / g, and the test results are shown in Table 1.

[0098] Table 1: Electrical performance detection results

[0099]

[0100] The above detailed description is a specific description of one of the feasible embodiments of the present application, and the embodiment is not used to limit the patent scope of the present application. Any equivalent implementation or change without departing from the present application shall be included in the scope of the technical solutions of the present application.

Claims

1. A method of preparing a metal-ion battery electrode material, characterized in that, The preparation method comprises the following steps: (1) washing, dewatering, and crushing plant leaf solid waste to obtain an electrode material carbon precursor; (2) embedding the electrode material carbon precursor in a conductive powder bed with an embedded electrode, and connecting both ends of the electrode to a pulse power supply; (3) setting pulse power supply parameters, high-temperature heat treatment under inert gas protection, cooling, and sieving to obtain the product. The pulse power supply parameters in step (3) include: the pulse current waveform is selected from one or more of a rectangular wave, a bell-shaped wave, a sharp wave, and a step wave; the pulse current peak value is 10-500 A; the pulse frequency is 10-100 Hz; the high-temperature heat treatment is performed 3 times, wherein the first pulse current waveform is a sharp wave or a bell-shaped wave, the second pulse current waveform is a rectangular wave, and the third pulse current waveform is a step wave. The first pulse current peak value is 10-50 A, the pulse frequency is 50-100 Hz, the heating time is 30-50 s, and the heating temperature is 900-1200℃; the second pulse peak current is 50-200 A, the pulse frequency is 10-50 Hz, the heating time is 40-60 s, and the heating temperature is 1500-2000℃; the third pulse peak current is 200-500 A, the pulse frequency is 10-50 Hz, the heating time is 10-200 s, and the heating temperature is 2000-3200℃.

2. The production method according to claim 1, characterized by, The plant leaf solid waste in step (1) includes one or both of grass and tree branches and leaves and waste tea leaves.

3. The preparation method according to claim 1, characterized in that, The dewatering treatment in step (1) is performed in a microwave electromagnetic field environment with a frequency of 915 MHz-5.8 GHz; a multi-mode microwave cavity is used for the dewatering treatment, the unit mass feed-in power intensity is 500-2000 W / Kg, and the heating time is 2-4 min.

4. The method of claim 1, wherein, The particle size of the conductive powder in the conductive powder bed before embedding the carbon precursor in step (2) is greater than 100 μm or less than 10 μm.

5. The preparation method according to claim 1, characterized in that, The high-temperature heat treatment in step (3) is performed 2 or more times, and the heat treatment temperature is 900-3200℃.

6. The method of claim 1, wherein, The sieve aperture in step (3) is 150-1800 mesh.

7. A metal ion battery electrode material prepared by the preparation method in any one of claims 1-6.

8. Application of a metal ion battery electrode material prepared by the preparation method in any one of claims 1-6 to a metal ion battery negative electrode.

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