Method for preparing microporous wood-based carbon electrode material by mycelial activation and application thereof

Abstract

The application provides a kind of mycelium activation preparation microporous wood-based carbon electrode material method and application, belong to battery electrode material field, the method includes: wood chip is mixed with liquid culture medium, compost bacillus according to proportion Fermentation, removes lignin by mycelium activation;After sterilization, the treated wood chip is mixed with nutrient solution, aspergillus tubigensis Fermentation, removes hemicellulose by mycelium activation;The obtained double bacteria treated wood chip is treated by stepwise temperature soft pressing and is densified, and finally high-temperature carbonization, that is, microporous wood-based carbon electrode material is obtained.The application adopts compost bacillus and aspergillus tubigensis double bacteria collaborative step-by-step treatment, maximally retains cellulose skeleton structure and crystallinity, avoids the damage of chemical method to skeleton;Combined with stepwise hydrothermal densification, a hierarchical porous structure with large specific surface area and narrow pore size distribution is formed, the material is uniform and defect-free, the obtained electrode material has excellent performance and good application prospect.

Description

Technical Field

[0001] This invention belongs to the technical field of battery electrode materials, specifically relating to a method and application of preparing microporous wood-based carbon electrode materials by mycelial activation. Background Technology

[0002] Wood, due to its wide availability, renewable nature, high carbon content, and natural three-dimensional interconnected porous structure, is an ideal precursor for the preparation of green carbon-based functional materials. Dense carbonized wood, prepared by removing lignin / hemicellulose, densification, and carbonization, has broad application prospects in fields such as supercapacitors and electrocatalysis.

[0003] Currently, the publicly disclosed technical routes for the core step of lignin and hemicellulose removal are mainly divided into three categories: chemical treatment, enzyme treatment, and single microbial treatment.

[0004] Chemical treatment: This method uses corrosive reagents such as strong alkalis (e.g., NaOH) and sulfites to chemically treat wood under high-temperature conditions, achieving high removal efficiency. However, it has significant drawbacks: First, the strong corrosiveness of strong alkalis and sulfites severely damages the cellulose skeleton and crystalline structure of the wood, leading to cracking of subsequent carbonized materials, decreased mechanical properties, and poor structural uniformity. Second, chemical reagents tend to remain inside the wood, reducing product purity and impairing the regularity of the microporous structure, thus affecting the performance of dense carbonized wood in applications such as electrode materials. Third, the chemical waste is difficult to treat and causes serious environmental pollution, which is inconsistent with the concept of green environmental protection.

[0005] Enzymatic treatment: This method uses biological enzymes such as laccase and hemicellulase to degrade wood in stages. The reaction conditions are mild and cause minimal damage to the cellulose skeleton. However, this method has obvious limitations: enzyme preparations are expensive to produce, have poor stability, and are prone to inactivation during the reaction, resulting in low treatment efficiency and long cycles; enzyme reactions are subject to strict requirements for pH, temperature, and other conditions, making process control difficult, batch-to-batch stability poor, and hindering large-scale production; furthermore, a single enzyme system cannot simultaneously and efficiently degrade lignin and hemicellulose, and its ability to regulate pore structure is insufficient.

[0006] Single-species microbial treatment: This method utilizes specific microorganisms such as white-rot fungi and brown-rot fungi to biodegrade wood. The reaction conditions are mild, environmentally friendly, and offer good selectivity. However, the treatment capacity of a single microorganism has functional limitations: a single microorganism cannot simultaneously and efficiently remove lignin and hemicellulose, easily leading to uneven degradation or localized over-degradation. This results in poor controllability of wood composition and microstructure, making it difficult to adapt well to subsequent densification and carbonization processes.

[0007] In summary, existing technologies suffer from problems such as heavy pollution and significant damage from chemical methods, high costs and poor stability from enzymatic methods, and low efficiency and poor controllability from single-bacterial methods. They have consistently failed to achieve a unified approach of precise control of wood components, preservation of structural integrity, and efficient densification and carbonization under green and mild conditions. Furthermore, no publicly available technical solutions have been found that organically integrate composite microbial synergistic stepwise pretreatment with controllable densification and high-temperature carbonization processes. Summary of the Invention

[0008] In view of this, the present invention provides a method and application for preparing microporous wood-based carbon electrode materials by mycelial activation, in order to solve the technical problems of heavy pollution and great damage of chemical treatment methods, high cost and poor stability of enzyme treatment methods, and low efficiency and poor controllability of single microbial treatment methods in the prior art.

[0009] To achieve the above-mentioned objective, this invention provides a method for preparing microporous wood-based carbon electrode materials by mycelial activation, comprising the following steps: S1. Mix wood chips with liquid culture medium and Bacillus composting in a ratio of 1g:40-60mL:1g and ferment to remove lignin by activating the mycelium of Bacillus composting. S2. Sterilize the wood chips treated in S1 to inactivate the residual Bacillus composting bacteria, and obtain Bacillus-treated wood chips; S3. Mix Bacillus-treated wood chips with nutrient solution and Aspergillus tabineus at a ratio of 4-5g:250mL:1g and ferment. Use Aspergillus tabineus mycelium to activate and remove hemicellulose to obtain dual-bacterial treated wood chips. S4. Take the double-bacterial treated wood chips and perform a stepped heating and pressing treatment to obtain dense wood chips; S5. The densified wood chips are carbonized at high temperature to obtain microporous wood-based carbon electrode material.

[0010] Preferably, the liquid culture medium in S1 comprises: yeast extract 0.5 g / L, peptone 1 g / L, KH2PO4 2 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, CaCl2·2H2O 0.3 g / L, FeCl3·6H2O 0.01 g / L, MnSO4·H2O 0.0016 g / L, ZnSO4·7H2O 0.0014 g / L, and CoCl2·6H2O 0.0020 g / L.

[0011] Preferably, the fermentation conditions described in S1 are: incubation at 50-55℃ and 180-220r / min for 8-10 days.

[0012] Preferably, the sterilization conditions described in S2 are sterilization at 121°C for 15 minutes.

[0013] Preferably, the nutrient solution in S3 has the following composition: 30 g / L sucrose, 3 g / L NaNO3, 0.5 g / L MgSO4·7H2O, 0.5 g / L KCl, 0.01 g / L FeSO4·4H2O, and 3 g / L K2HPO4, with a pH of 6.0~6.5.

[0014] Preferably, the fermentation conditions described in S3 are: incubation at 30-35℃ and 200-250r / min for 4-5 days.

[0015] Preferably, the stepped temperature increase and pressure reduction process described in S4 is as follows: the pressure is maintained at 50℃ / 1MPa, 70℃ / 3MPa, and 100℃ / 5MPa for 10 minutes each, then the pressure is increased to 7MPa and maintained for 2 hours, and then the temperature is reduced to 50℃ and maintained at 7MPa for 3 hours.

[0016] Preferably, before the stepped temperature rise and pressure treatment in S4, the double-bacterial treated wood chips are repeatedly rinsed with deionized water and dried, wherein the drying is freeze drying or low-temperature drying at 40-60℃.

[0017] Preferably, the high-temperature carbonization conditions in S5 are as follows: under a nitrogen atmosphere, the temperature is increased to 800-850℃ at a heating rate of 5℃ / min, carbonized for 2-3 hours, and then naturally cooled.

[0018] Application of a microporous wood-based carbon electrode material prepared by the method described in this invention in a battery pack.

[0019] This invention employs a stepwise synergistic treatment of Bacillus compostii and Aspergillus tabineus, combined with a stepped hydrothermal densification and high-temperature carbonization process to prepare microporous wood-based carbon electrode materials.

[0020] Extracellular enzyme systems such as lignin peroxidase and manganese peroxidase secreted by *Bacillus compostii* can selectively cleave β-aryl ether bonds and C / C bonds in lignin molecules, gradually degrading the large lignin molecules encapsulated on the surface of cellulose fibers into smaller molecules and breaking down the outer coating layer of the cellulose skeleton. Hemicellulase systems secreted by *Aspergillus tabineum* further act on the glycosidic bonds of the hemicellulose backbone and side chains, efficiently removing hemicellulose components filling the spaces between cellulose microfibrils. The stepwise treatment by the two strains has a synergistic effect: after the *Bacillus compostii* pretreatment breaks down the lignin barrier, the cellulose skeleton is fully exposed, providing better substrate accessibility for *Aspergillus tabineum*; the intermediate sterilization treatment completely inactivates *Bacillus compostii*, avoiding interference between the strains and ensuring that each stage of the reaction is independent and controllable, achieving selective and orderly removal of lignin and hemicellulose.

[0021] The gradual removal of lignin and hemicellulose creates a hierarchical porous structure within the wood: lignin removal relaxes the cell walls, releasing cellulose microfibrils; hemicellulose removal further opens up nanochannels between the microfibrils. While preserving the macroscopic integrity of the cellulose skeleton, numerous micropores and small mesopores are formed, constructing a multi-level pore system ranging from nanoscale micropores to micrometer-scale cell cavities.

[0022] Wood treated with dual microorganisms exhibits good plasticity due to the removal of lignin / hemicellulose. The stepped heating and cooling process applies controlled physical compression to the wood through progressively increasing temperature and pressure: the low-temperature, low-pressure stage ensures uniform moisture distribution and initial softening; the medium-temperature, medium-pressure stage promotes gradual cell wall collapse and pore regularization; the high-temperature, high-pressure stage further compacts the wood while inducing hydrogen bond reconstruction between cellulose molecular chains; and the pressure-holding and cooling stage fixes the dense microstructure and prevents elastic recovery. This stepped treatment avoids skeletal damage caused by sudden high pressure, achieving uniform density and directional pore arrangement in the wood volume.

[0023] During high-temperature carbonization under a protective atmosphere, the residual cellulose skeleton undergoes pyrolysis, and non-carbon elements escape in gaseous form, further enriching the microporous structure; simultaneously, the formation of graphite microcrystals endows the material with excellent electronic conductivity. The hierarchical pores formed by the dual-bacterial treatment and the regular pore orientation after densification treatment together construct the microstructure of the electrode material with short ion transport distances and continuous electronic conduction paths.

[0024] Compared with the prior art, the present invention has the following beneficial effects: This invention employs a synergistic stepwise treatment method using Bacillus compostii and Aspergillus tabineus, replacing corrosive reagents such as strong alkalis and sulfites in traditional chemical methods. The reaction conditions are mild, requiring no high temperature, high pressure, or expensive enzyme preparations, and no toxic waste liquid is generated. The strains can be recycled, and it has significant advantages such as being green and environmentally friendly, low cost, having good process stability, and being easy to scale up.

[0025] This invention achieves selective and orderly removal of lignin and hemicellulose through a two-microbe stepwise synergistic treatment, maximizing the preservation of the natural structure and crystallinity of the cellulose skeleton and avoiding destructive damage to the skeleton by chemical methods. Combined with a step-by-step hydrothermal densification treatment, the wood pore structure is made uniform, dense, and oriented, ultimately forming a hierarchical porous structure with a large specific surface area and narrow pore size distribution. The material structure is uniform and free of macroscopic defects. Attached Figure Description

[0026] Figure 1 The nitrogen adsorption-desorption curve of the wood-based carbon electrode material prepared by the method provided in the specific implementation embodiment is shown in the figure. Figure 2 The pore size distribution diagram is shown for the wood-based carbon electrode material prepared by the method provided in the specific embodiment. Figure 3 The CV voltage window test diagram of the wood-based carbon electrode material prepared by the method provided in the specific embodiment at a scan rate of 1mV / s is shown. Figure 4 The wood-based carbon electrode material prepared by the method provided in the specific embodiment has a performance of 1 mA / cm 2 The GCD curve at the current density. Detailed Implementation

[0027] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions of the embodiments of the present invention will be clearly and completely described below with reference to the accompanying drawings. Obviously, the described embodiments are only some, not all, of the embodiments of the present invention. All other embodiments obtained by those skilled in the art based on the described embodiments of the present invention without creative effort are within the scope of protection of the present invention.

[0028] The sources of the microbial materials used in the specific implementation are as follows: Bacillus compostii (also known as Bacillus spp. in soil compost): Purchased from the China General Microbiological Culture Collection Center (CGMCC), with accession number CGMCC 1.12360. The public can search for and purchase this strain through the official product page (https: / / www.cgmcc.net / resources / details?uuid=792fb3c1-8ef2-11f0-94c6-78ac44479d74).

[0029] Aspergillus tabineum: Purchased from BNCC Biotechnology Co., Ltd. (BNCC), where the product number is BNCC 190278 (this strain is numbered CICC 40613 in other collections). The public can find and purchase this strain through the official product page (https: / / www.bncc.com / pro / p2 / 8 / p_190278.html).

[0030] Example 1 (1) Wood chip pretreatment: Select linden wood, cut it into wood chips of 2cm×2cm×1cm, rinse with a large amount of deionized water to remove surface impurities, place the clean wood chips in an autoclave, sterilize at 125℃ for 30 minutes, cool and place in a sterile environment for later use.

[0031] (2) Preparation of liquid culture medium: Composition: yeast extract 0.5 g / L, peptone 1 g / L, KH2PO4 2 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, CaCl2·2H2O 0.3 g / L, FeCl3·6H2O 0.01 g / L, MnSO4·H2O 0.0016 g / L, ZnSO4·7H2O 0.0014 g / L and CoCl2·6H2O 0.0020 g / L.

[0032] (3) Treatment stage of Bacillus composting (removal of lignin): The ratio of wood chips, liquid culture medium and Bacillus composting is 1:50:1 (g:mL:g). Place the wood chips and liquid culture medium in an autoclave at 121℃ for 15 minutes. Mix the three in a sterile environment, place the Erlenmeyer flask on a shaker, and incubate for 10 days at 55℃ and 180r / min.

[0033] (4) Intermediate treatment (necessary operation for double inoculation): The wood chips treated with Bacillus composting were taken out and gently rinsed three times with sterile deionized water to remove residual mycelia and metabolic products on the surface. Then the wood chips were put back into the autoclave and sterilized at 121°C for 15 minutes to inactivate the residual Bacillus composting and prevent it from competing with Aspergillus tabineum for nutrients. After cooling, they were used for later use to obtain Bacillus-treated wood chips.

[0034] (5) Prepare nutrient solution: 30 g / L sucrose, 3 g / L NaNO3, 0.5 g / L MgSO4·7H2O, 0.5 g / L KCl, 0.01 g / L FeSO4·4H2O and 3 g / L K2HPO4, keep the pH in the range of 6.0~6.5, then dispense into 300 mL Erlenmeyer flasks and seal the flasks with sealing film.

[0035] (6) Tabine Aspergillus treatment stage (removal of hemicellulose): The ratio of Bacillus-treated wood chips, nutrient solution and Tabine Aspergillus is 5:250:1 (g:mL:g). The Bacillus-treated wood chips and nutrient solution are placed in an autoclave at 121℃ for 15 minutes for sterilization. After mixing the three in a sterile environment, the Erlenmeyer flask is placed in a shaker at 35℃ and 200r / min for 4 days to obtain double-bacterial treated wood chips.

[0036] (7) Preparation of microporous carbonized wood: Take out the wood chips treated with double bacteria, rinse them repeatedly with deionized water and dry them. After soaking in water for 5 minutes, take out the wood chips and wipe off the water. Hold the pressure of 1 MPa at 50°C for 10 minutes; raise the temperature to 70°C and hold the pressure of 3 MPa for 10 minutes; continue to raise the temperature and pressure to 100°C and hold the pressure of 5 MPa for 10 minutes; then raise the pressure to 7 MPa and hold for 2 hours, then lower the temperature to 50°C and hold the pressure of 7 MPa for 3 hours. Then place the wood in a tube furnace and raise the temperature to 800°C at a rate of 5°C per minute under a nitrogen atmosphere for 3 hours, and then let it cool naturally to room temperature to obtain microporous wood-based carbon electrode material.

[0037] Example 2 (1) Wood chip pretreatment: Select linden wood, cut it into wood chips of 2cm×2cm×1cm, rinse with a large amount of deionized water to remove surface impurities, place the clean wood chips in an autoclave, sterilize at 125℃ for 30 minutes, cool and place in a sterile environment for later use.

[0038] (2) Preparation of liquid culture medium: Composition: yeast extract 0.5 g / L, peptone 1 g / L, KH2PO4 2 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, CaCl2·2H2O 0.3 g / L, FeCl3·6H2O 0.01 g / L, MnSO4·H2O 0.0016 g / L, ZnSO4·7H2O 0.0014 g / L and CoCl2·6H2O 0.0020 g / L.

[0039] (3) Treatment stage of Bacillus composting (removal of lignin): The ratio of wood chips, liquid culture medium and Bacillus composting is 1:40:1 (g:mL:g). The wood chips and liquid culture medium are placed in an autoclave at 121℃ for 15 minutes for sterilization. After mixing the three in a sterile environment, the Erlenmeyer flask is placed on a shaker and incubated at 50℃ and 220r / min for 9 days.

[0040] (4) Intermediate treatment (necessary operation for double inoculation): The wood chips treated with Bacillus composting were taken out and gently rinsed three times with sterile deionized water to remove residual mycelia and metabolic products on the surface. Then the wood chips were put back into the autoclave and sterilized at 121°C for 15 minutes to inactivate the residual Bacillus composting and prevent it from competing with Aspergillus tabineum for nutrients. After cooling, they were used for later use to obtain Bacillus-treated wood chips.

[0041] (5) Prepare nutrient solution: 30 g / L sucrose, 3 g / L NaNO3, 0.5 g / L MgSO4·7H2O, 0.5 g / L KCl, 0.01 g / L FeSO4·4H2O and 3 g / L K2HPO4, keep the pH in the range of 6.0~6.5, then dispense into 300 mL Erlenmeyer flasks and seal the flasks with sealing film.

[0042] (6) Tabine Aspergillus treatment stage (removal of hemicellulose): The ratio of Bacillus-treated wood chips, nutrient solution and Tabine Aspergillus is 4:250:1 (g:mL:g). The Bacillus-treated wood chips and nutrient solution are placed in an autoclave at 121℃ for 15 minutes for sterilization. After mixing the three in a sterile environment, the Erlenmeyer flask is placed in a shaker at 30℃ and 250r / min for 5 days to obtain double-bacterial treated wood chips.

[0043] (7) Preparation of microporous carbonized wood: Take out the wood chips treated with double bacteria, rinse them repeatedly with deionized water and dry them. After soaking in water for 5 minutes, take out the wood chips and wipe off the water. Hold the pressure of 1 MPa at 50°C for 10 minutes; raise the temperature to 70°C and hold the pressure of 3 MPa for 10 minutes; continue to raise the temperature and pressure to 100°C and hold the pressure of 5 MPa for 10 minutes; then raise the pressure to 7 MPa and hold for 2 hours, then lower the temperature to 50°C and hold the pressure of 7 MPa for 3 hours. Then place the wood in a tube furnace and raise the temperature to 850°C at a rate of 5°C per minute under a nitrogen atmosphere for 2 hours, and then let it cool naturally to room temperature to obtain microporous wood-based carbon electrode material.

[0044] Example 3 (1) Wood chip pretreatment: Select linden wood, cut it into wood chips of 2cm×2cm×1cm, rinse with a large amount of deionized water to remove surface impurities, place the clean wood chips in an autoclave, sterilize at 125℃ for 30 minutes, cool and place in a sterile environment for later use.

[0045] (2) Preparation of liquid culture medium: Composition: yeast extract 0.5 g / L, peptone 1 g / L, KH2PO4 2 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, CaCl2·2H2O 0.3 g / L, FeCl3·6H2O 0.01 g / L, MnSO4·H2O 0.0016 g / L, ZnSO4·7H2O 0.0014 g / L and CoCl2·6H2O 0.0020 g / L.

[0046] (3) Treatment stage of Bacillus composting (removal of lignin): The ratio of wood chips, liquid culture medium and Bacillus composting is 1:60:1 (g:mL:g). The wood chips and liquid culture medium are placed in an autoclave at 121℃ for 15 minutes for sterilization. After mixing the three in a sterile environment, the Erlenmeyer flask is placed on a shaker and incubated at 53℃ and 200r / min for 8 days.

[0047] (4) Intermediate treatment (a necessary step for double inoculation): Remove the wood chips treated with Bacillus compostii and rinse them gently 2-3 times with sterile deionized water to remove residual mycelia and metabolic products on the surface. Then put the wood chips back into the autoclave and sterilize at 121°C for 15 minutes to inactivate the residual Bacillus compostii and prevent it from competing with Aspergillus tabineum for nutrients. After cooling, they are ready for use to obtain Bacillus-treated wood chips.

[0048] (5) Prepare nutrient solution: 30 g / L sucrose, 3 g / L NaNO3, 0.5 g / L MgSO4·7H2O, 0.5 g / L KCl, 0.01 g / L FeSO4·4H2O and 3 g / L K2HPO4, keep the pH in the range of 6.0~6.5, then dispense into 300 mL Erlenmeyer flasks and seal the flasks with sealing film.

[0049] (6) Tabine Aspergillus treatment stage (removal of hemicellulose): The ratio of Bacillus-treated wood chips, nutrient solution and Tabine Aspergillus is 6:250:1 (g:mL:g). The Bacillus-treated wood chips and nutrient solution are placed in an autoclave at 121℃ for 15 minutes for sterilization. After mixing the three in a sterile environment, the Erlenmeyer flask is placed in a shaker at 34℃ and 240r / min for 4.5 days to obtain double-bacterial treated wood chips.

[0050] (7) Preparation of microporous carbonized wood: Take out the wood chips treated with double bacteria, rinse them repeatedly with deionized water and dry them. After soaking in water for 5 minutes, take out the wood chips and wipe off the water. Hold the pressure of 1 MPa at 50°C for 10 minutes; raise the temperature to 70°C and hold the pressure of 3 MPa for 10 minutes; continue to raise the temperature and pressure to 100°C and hold the pressure of 5 MPa for 10 minutes; then raise the pressure to 7 MPa and hold for 2 hours, then lower the temperature to 50°C and hold the pressure of 7 MPa for 3 hours. Then place the wood in a tube furnace and raise the temperature to 820°C at a rate of 5°C per minute under a nitrogen atmosphere for 2.5 hours, then let it cool naturally to room temperature to obtain microporous wood-based carbon electrode material.

[0051] Comparative Example 1 This comparative example is similar to the example, except that this comparative example only uses Bacillus composting to treat the wood chips. That is, steps (5) and (6) are not used in this comparative example. The wood chips treated with Bacillus composting are directly subjected to step-by-step heating and pressing treatment and high-temperature carbonization to obtain wood-based carbon electrode materials.

[0052] Comparative Example 2 This comparative example is similar to the example, except that this comparative example is treated with Aspergillus tabineus only, that is, steps (2) and (3) are not included in this comparative example to obtain wood-based carbon electrode material.

[0053] Comparative Example 3 Linden wood was selected and cut into 2cm×2cm×1cm pieces. The pieces were soaked in water for 5 minutes, then removed and dried. The wood was then heated to 50℃ and held at 1 MPa for 10 minutes; the temperature was increased to 70℃ and held at 3 MPa for 10 minutes; the temperature and pressure were further increased to 100℃ and held at 5 MPa for 10 minutes; then the pressure was increased to 7 MPa and held for 2 hours, followed by a decrease to 50℃ and a holding at 7 MPa for 3 hours. The wood was then placed in a tube furnace and heated to 800℃ at a rate of 5℃ per minute under a nitrogen atmosphere for 3 hours. Afterward, it was naturally cooled to room temperature to obtain a microporous wood-based carbon electrode material.

[0054] The carbon electrode materials prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to nitrogen adsorption-desorption and pore size distribution tests. The test results are as follows: Figure 1 and Figure 2 The nitrogen adsorption-desorption isotherms of all samples exhibited typical IUPAC Type I characteristics. In the low-pressure region (P / P0 < 0.1), the adsorption capacity rapidly increased and quickly plateaued, without a significant hysteresis loop, indicating that the material is predominantly microporous. Among them, the sample treated with dual bacteria and then hot-pressed (Example 1) showed the highest nitrogen adsorption capacity, reaching approximately 135 cm⁻¹. 3 / g, Example 2 approximately 100 cm 3 / g, Example 3, approximately 95 cm 3 / g, the specific surface area of ​​the sample was significantly higher than that of each control group, with the single treatment of Bacillus subtilis (Comparative Example 1) and the single treatment of Aspergillus tabineus (Comparative Example 2) both having a specific surface area of ​​approximately 85 cm². 3 / g, while the log steps, after hot pressing and direct carbonization (Comparative Example 3), only amount to about 60 cm. 3 / g. Pore size distribution test results further confirmed that the pores of each treatment group were concentrated in the micropore range of about 1 nm, and the pore size distribution was narrow and uniform. Among them, the micropore volume of the hot-pressed sample after dual-bacterial synergistic treatment was significantly higher than that of other groups, indicating that the process can efficiently etch wood components and construct a high-content, highly uniform microporous structure, significantly improving the specific surface area and pore volume of the material, providing a favorable structural basis for its application in the field of electrochemistry.

[0055] The carbon electrode materials prepared in Examples 1-3 and Comparative Examples 1-3 were subjected to CV voltage window tests at a scan rate of 1 mV / s and 1 mA / cm². 2 The GCD curve was tested at the current density, and the test results were as follows: Figure 3 and Figure 4 At a scan rate of 1 mV·s -1 In the CV test, the hot-pressed sample treated with dual bacteria had the largest CV curve closure area. The current response range of the sample in Example 1 was -0.0052 A to 0.0030 A, the current response range of the sample in Example 2 was -0.0031 A to 0.0014 A, and the current response range of the sample in Example 3 was -0.0020 A to 0.0009 A, which were significantly higher than those of the control groups. The ranges of Comparative Example 1 (single Bacillus subtilis) and Comparative Example 2 (single Aspergillus tabineus) were -0.0021 to 0.0010 A and -0.0009 to 0.0005 A, respectively, while the range of Comparative Example 3 (log stepped hot-pressed and directly carbonized) was only -0.0008 to 0.0004 A, indicating that dual-bacterial synergistic modification can significantly improve the charge storage capacity of the material.

[0056] At a current density of 1 mA·cm -2 In the GCD test, the discharge time of the hot-pressed samples after dual-strain treatment reached 12,500 s in Example 1, about 11,000 s in Example 2, and about 7,600 s in Example 3, all of which were higher than those of Comparative Example 1 (single Bacillus subtilis, about 6,200 s), Comparative Example 2 (single Aspergillus tabineus, about 3,500 s), and Comparative Example 3 (log stepped hot-pressed and then directly carbonized, about 2,200 s).

[0057] Meanwhile, all samples achieved a peak charging voltage of 0.8V, allowing for a direct comparison of voltage drop differences during the discharge phase. The three comparative samples exhibited steep discharge curves, rapid voltage decay rates, large voltage drops during discharge, significant polarization effects, and poor charge storage stability. In contrast, the discharge curves of the example samples showed a significantly slower slope and gentler voltage decay; Examples 3, 2, and 1 showed higher potential retention values ​​and significantly suppressed voltage drops for the same discharge duration. These results indicate that the modification treatment effectively reduced the internal resistance of the electrode system, alleviated charge-discharge polarization, and improved the material's stable output capability, with Example 1 exhibiting the best voltage maintenance performance.

[0058] The dual-strain synergistic treatment process employed in this invention can significantly improve the specific capacitance and ion transport efficiency of wood-based electrode materials by selectively removing lignin / hemicellulose and constructing a hierarchical porous structure. This is significantly better than that of single-strain treated and unmodified control samples, demonstrating excellent electrochemical performance and application potential.

[0059] The above are merely specific embodiments of the present invention, but the scope of protection of the present invention is not limited thereto. The scope of protection of the present invention should be determined by the scope of the claims.

Claims

1. A method for preparing microporous wood-based carbon electrode materials by activating mycelia, characterized in that, Includes the following steps: S1. Mix wood chips with liquid culture medium and Bacillus composting in a ratio of 1g:40-60mL:1g and ferment to remove lignin by activating the mycelium of Bacillus composting. S2. Sterilize the wood chips treated in S1 to obtain Bacillus-treated wood chips; S3. Mix Bacillus-treated wood chips with nutrient solution and Aspergillus tabineus at a ratio of 4-6g:250mL:1g and ferment. Use Aspergillus tabineus mycelium to activate and remove hemicellulose to obtain dual-bacterial treated wood chips. S4. Take the double-bacterial treated wood chips and perform a stepped heating and pressing treatment to obtain dense wood chips; S5. The densified wood chips are carbonized at high temperature to obtain microporous wood-based carbon electrode material.

2. The method according to claim 1, characterized in that, The liquid culture medium described in S1 consists of: yeast extract 0.5 g / L, peptone 1 g / L, KH2PO4 2 g / L, K2HPO4 0.5 g / L, MgSO4·7H2O 0.5 g / L, CaCl2·2H2O 0.3 g / L, FeCl3·6H2O 0.01 g / L, MnSO4·H2O 0.0016 g / L, ZnSO4·7H2O 0.0014 g / L, and CoCl2·6H2O 0.0020 g / L.

3. The method according to claim 1, characterized in that, The fermentation conditions described in S1 are: incubation at 50-55℃ and 180-220r / min for 8-10 days.

4. The method according to claim 1, characterized in that, The sterilization conditions described in S2 are sterilization at 121°C for 15 minutes.

5. The method according to claim 1, characterized in that, The nutrient solution described in S3 consists of: 30 g / L sucrose, 3 g / L NaNO3, 0.5 g / L MgSO4·7H2O, 0.5 g / L KCl, 0.01 g / L FeSO4·4H2O, and 3 g / L K2HPO4, with a pH of 6.0~6.

5.

6. The method according to claim 1, characterized in that, The fermentation conditions described in S3 are: incubation at 30-35℃ and 200-250r / min for 4-5 days.

7. The method according to claim 1, characterized in that, The stepped temperature increase and pressure reduction process described in S4 is as follows: hold the pressure at 50℃ / 1MPa, 70℃ / 3MPa, and 100℃ / 5MPa for 10 minutes each, then increase the pressure to 7MPa and hold for 2 hours, and then decrease the temperature to 50℃ and hold at 7MPa for 3 hours.

8. The method according to claim 1, characterized in that, Before the stepwise temperature rise and pressure treatment in S4, the wood chips treated with the two bacteria are repeatedly rinsed with deionized water and dried. The drying is freeze drying or low-temperature drying at 40-60℃.

9. The method according to claim 1, characterized in that, The conditions for high-temperature carbonization in S5 are as follows: under a nitrogen atmosphere, the temperature is increased to 800-850℃ at a heating rate of 5℃ / min, carbonized for 2-3 hours, and then naturally cooled.

10. The application of a microporous wood-based carbon electrode material prepared by the method according to any one of claims 1-9 in a battery pack.

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