Organic matter coated red phosphorus-boron-carbon composite material as well as preparation method and application thereof

Abstract

The invention relates to an organic matter coated red phosphorus-boron-carbon composite material and a preparation method and application thereof.The preparation method comprises the steps that a biomass raw material is activated and calcined and then reacts with boric acid, a boron-carbon matrix with a rich pore channel structure is obtained, then the boron-carbon matrix and red phosphorus are mixed and calcined, the obtained red phosphorus-carbon material is coated with an organic matter and then freeze-dried, and a target material is obtained. The obtained material is used as a negative electrode material of a potassium ion battery, so that the capacity, the cycle performance and the rate capability of the potassium ion battery loaded with the composite material are improved, and the composite material has a good application prospect.

Description

Technical Field

[0001] The present invention belongs to the field of electrode materials, and in particular relates to an organic-coated red phosphorus boron-carbon composite material, a preparation method thereof, and an application thereof. Background Art

[0002] Lithium-ion batteries (LIBs) are rapidly developing due to their high energy density and excellent cycle performance. However, the uneven distribution of lithium resources and their high cost hinder the further development of LIB-based energy storage devices. In this context, potassium-ion batteries (KIBs), with their abundant resources, similar standard reduction electrode potentials to lithium, and similar operating principles, have become one of the most promising alternatives to LIBs, especially in future large-scale energy storage.

[0003] In recent years, research has intensively explored secondary battery materials. Red phosphorus (RP) stands out among numerous anode materials due to its high theoretical specific capacity, moderate potassium insertion potential, and abundant natural reserves. However, potassium-ion batteries loaded with red phosphorus electrodes exhibit poor rate capability and electrochemical reversibility. Therefore, modifying red phosphorus electrodes and combining them with porous carbon materials has become an effective approach to improving their performance. For example, Patent 202311055874.2 discloses a self-supporting cotton biomass carbon-supported red phosphorus sodium-ion battery anode material and its preparation method. The carbon-supported red phosphorus materials obtained in some examples of this patent exhibit a low first-cycle specific capacity of 300-450 mAh / g. In some examples, the capacity retention rate is less than 20%, and the cycling performance is unstable, with some examples exhibiting poor performance. Therefore, further research on how to combine and modify red phosphorus materials to obtain potassium-ion red phosphorus electrode materials with excellent cycling performance is crucial for this invention and is also a key area of research.

[0004] Therefore, developing a new type of red phosphorus carbon material, improving the cycle stability and battery performance of potassium ion batteries, and promoting the application of red phosphorus carbon materials and the development of potassium ion batteries have important practical value and market significance. Summary of the Invention

[0005] The technical problem to be solved by the present invention is to provide an organic-coated red phosphorus boron-carbon composite material and a preparation method and application thereof.

[0006] In order to solve the above problems, the technical solution adopted by the present invention is: Technical Topic 1: The present invention provides an organic-coated red phosphorus boron-carbon composite material, the preparation method of which comprises: S1: crushing the biomass raw materials and screening them for pretreatment; S2: calcining the pretreated biomass powder to obtain biomass carbon material PC; S3: mixing the PC obtained in step S2 with a boric acid solution and performing a hydrothermal reaction, and the reaction solution is centrifuged, washed, and dried to obtain a boron-doped carbon material BC; S4: vacuum-packaging the red phosphorus and the BC obtained in step S3, and calcining them to obtain a red phosphorus boron-carbon composite material RP@BC; S5: dissolving hyaluronic acid in a morpholineethanesulfonic acid buffer solution, then adding NHS, EDC and tyramine in sequence, reacting them fully at room temperature, and freeze-drying the product to obtain a tyramine-modified hyaluronic acid freeze-dried product; S6: dissolving the freeze-dried product obtained in S5 with RP@BC, reacting them by ultrasonication, and freeze-drying to obtain an organic-coated red phosphorus boron-carbon composite material; The biomass raw materials include one or more of burdock roots, corn silk, pomegranate seeds, corn stalks, orange peels and sun-dried loofah pulp.

[0007] As a further improvement of the embodiment of the present invention, the pretreatment described in S1 is: weighing potassium hydroxide and placing it in water, stirring it thoroughly until it dissolves, adding biomass raw material powder thereto, treating it at 60~100℃ for 2~6h, collecting the precipitate by centrifugation, and placing it in an oven for air drying; the mass ratio of the biomass raw material powder to potassium hydroxide is 1:2~4.

[0008] As a further improvement of the embodiment of the present invention, the calcination in S2 is: placing in a tubular furnace with an argon atmosphere, heating from room temperature to 600-1000°C at a rate of 3-8°C / min, keeping warm for 1-3 hours, and naturally cooling to room temperature.

[0009] As a further improvement of the embodiment of the present invention, the ratio of PC and boric acid in S3 is 1g:0.1~0.5mol; the hydrothermal reaction in S3 is: placed in a hydrothermal reactor, reacted at 150~250℃ for 3~8h, and naturally cooled to room temperature.

[0010] As a further improvement of the embodiment of the present invention, the mass ratio of red phosphorus to BC in S4 is 1.5~4.5:1.

[0011] As a further improvement of the embodiment of the present invention, the calcination in S4 is: heating to 400~600°C at a rate of 3~5°C / min, keeping warm for 3~5 hours, cooling to 200~400°C at a rate of 0.5~1.5°C / min, keeping warm for 18~30 hours, and naturally cooling to room temperature; the vacuum degree of the vacuum packaging in S4 is -1~-3 bar.

[0012] As a further improvement of the embodiment of the present invention, the molar ratio of morpholineethanesulfonic acid, hyaluronic acid, NHS, EDC and butyric acid in S5 is 0.5:3~8:15~25:15~25:10~20; the concentration of the morpholineethanesulfonic acid buffer solution is 0.01 mol / L, and the pH is 5.5.

[0013] As a further improvement of the embodiment of the present invention, the mass ratio of the freeze-dried product to RP@BC in S6 is 3:8-12.

[0014] Technical Topic 2: The present invention provides a method for preparing an organic-coated red phosphorus boron-carbon composite material as described in the first technical subject.

[0015] Technical Theme 3: The present invention provides an application of an organic-coated red phosphorus boron-carbon composite material as described in a first technical subject in the field of potassium ion battery electrode materials.

[0016] The beneficial effects of adopting the above technical solution are: 1. Using highly conductive biomass-based porous carbon materials as the matrix, a BC matrix with a rich pore structure was prepared. Subsequently, red phosphorus was evenly deposited in the pore structure of the BC by evaporation deposition. In addition, by introducing organic components to modify the red phosphorus boron-carbon composite material, the specific surface area of the material was increased, promoting full contact between the electrode and the electrolyte, and promoting the electrochemical reaction. Compared with pure red phosphorus material, the cycle performance and rate performance of the battery loaded with this material were significantly improved.

[0017] 2. The potassium ion battery loaded with the organic-coated red phosphorus boron-carbon composite material obtained in the present invention can maintain a specific capacity of more than 47% in 0-2 cycles at a current density of 0.1 A / g, and can reach a maximum of 55.3%. The specific capacity after 100 cycles at a current density of 0.1 A / g can reach a maximum of 64.6% compared with the 5th cycle, showing good cycle performance. BRIEF DESCRIPTION OF THE DRAWINGS

[0018] Figure 1 This is a scanning electron microscope image of the HT@RP@BC composite material obtained in Example 1 of the present invention; Figure 2 This is a transmission electron microscopy image of the HT@RP@BC composite material obtained in Example 1 of the present invention; Figure 3 1 is the nitrogen adsorption-desorption isotherm curve of the BC and HT@RP@BC composite materials obtained in Example 1 of the present invention; Figure 4 This is the pore size distribution diagram of the BC and HT@RP@BC composite materials obtained in Example 1 of the present invention; Figure 5This is a graph showing the rate performance test results of the HT@RP@BC, RP@BC, and RP composite electrode materials obtained in Example 1 of the present invention; Figure 6 This is a graph showing the cycling performance test results of the HT@RP@BC, RP@BC and RP composite electrode materials obtained in Example 1 of the present invention at a current density of 0.1 A / g. DETAILED DESCRIPTION

[0019] In order to make the objectives, technical solutions and advantages of the present invention more clear, the invention is clearly and completely described below in conjunction with specific embodiments.

[0020] Example 1 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the lyophilized product and 150 mg of RP@BC material in 12 mL of deionized water, stir for 3 h, sonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC; The obtained HT@RP@BC composite material was tested by SEM and TEM. Figure 1 and Figure 2 As shown, it can be observed that the material contains rich pore structures; The BC and HT@RP@BC composite materials obtained in Example 1 were subjected to nitrogen adsorption and desorption tests, and the obtained nitrogen adsorption and desorption isotherm curves and pore size distribution diagrams were shown as follows: Figure 3 and Figure 4 shown.

[0021] Example 2 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 10 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0022] Example 3 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 50 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0023] Example 4 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed 3 times with ethanol in advance and dried under vacuum at 60°C for later use) and BC material with a mass ratio of 1.5:1 were fully ground using an agate mortar, placed in a pre-cleaned ampoule tube, and vacuumed using a water pump to reduce the vacuum degree in the ampoule tube to -1 bar. The tube was sealed at high temperature using a flame gun; the vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature; the ampoule tube was taken out and placed in a glove box, and the ampoule tube was broken open using a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC; S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0024] Example 5 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed 3 times with ethanol in advance and then vacuum dried at 60°C for later use) and BC material with a mass ratio of 4.5:1 were fully ground using an agate mortar, placed in a pre-cleaned ampoule tube, and vacuum-sealed using a water pump to reduce the vacuum degree in the ampoule tube to -1 bar. The tube was sealed at high temperature using a flame gun; the vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature; the ampoule tube was taken out and placed in a glove box, and the ampoule tube was broken open using a glass tube cutter. The red phosphorus boron carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron carbon composite material RP@BC; S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0025] Example 6 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 0.6 g (100 kDa, 3 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 0.940 g (15 mmol) of NHS. After 5 min, add 1.436 g (15 mmol) of EDC, and then add 0.873 g (10 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0026] Example 7 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1.6 g (100 kDa, 8 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.560 g (25 mmol) of NHS. After 5 min, add 2.394 g (25 mmol) of EDC, and then add 1.747 g (20 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0027] Example 8 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 120 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0028] Example 9 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 180 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain an organic-coated red phosphorus boron-carbon composite material.

[0029] Example 10 S1: Wash corn straw with deionized water several times, then ultrasonically clean until the cleaning solution is basically clear; place the treated corn straw in a forced air drying oven and dry it at 90°C for 24 hours; after complete drying, crush it with a grinder, sieve it with a 300-mesh sieve, and place the sieved corn straw powder in a 90°C oven to dry for later use; weigh 4g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of corn straw powder to it, heat it in an oil bath at 60°C for 6 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and force dry it for 12 hours; S2: The pretreated corn straw powder obtained in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 600°C at a rate of 3°C / min, kept at this temperature for 3 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 150°C for 8 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70°C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC.

[0030] Example 11 S1: Wash the orange peel several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated orange peel in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, crush it with a grinder, and then sieve it with a 300-mesh screen. The sieved orange peel powder is placed in a 90°C oven to dry for later use; weigh 2g of KOH and add it to 50mL of distilled water. After magnetic stirring for 30 minutes, 1g of orange peel powder is added to the water, and the water is heated in an oil bath at 100°C for 2 hours. The precipitate is collected by centrifugation and placed in a 90°C oven and forced air dried for 12 hours; S2: The pretreated orange peel powder obtained in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 1000°C at a rate of 8°C / min, kept at this temperature for 1 hour, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 hour, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 250°C for 3 hours. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70°C for 12 hours to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC.

[0031] Comparative Example 1 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the cleaning solution is basically clear; place the treated burdock root in a forced air drying oven at 90°C for 24 hours; after it is completely dried, grind it with a grinder, and then sieve it with a 300-mesh sieve. The sieved burdock root powder is placed in a 90°C oven to dry for later use; Weigh 2 g of KOH and place it in 50 mL of distilled water. After magnetic stirring for 30 min, add 1 g of burdock root powder. Heat in an 80°C oil bath for 4 h. Collect the precipitate by centrifugation and place it in a 90°C oven with forced air to dry for 12 h. S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and vacuum dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar, placed in an ampoule tube that had been cleaned in advance, and vacuumed using a water pump to reduce the vacuum degree in the ampoule tube to -1 bar. The tube was sealed at high temperature using a flame gun; the vacuum-sealed ampoule tube was placed in a quartz tube and calcined. The reaction conditions were: heating to 500°C at a rate of 4°C / min, keeping warm for 4 hours, then cooling to 300°C at a rate of 1°C / min, keeping warm for 24 hours, and naturally cooling to room temperature; the ampoule tube was taken out and placed in a glove box, and the ampoule tube was broken open using a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, the white phosphorus was washed off, filtered, and washed three times with ethanol by centrifugation. It was dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC.

[0032] Comparative Example 2 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 75 mg of the RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC.

[0033] Comparative Example 3 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box. The ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 225 mg of RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC.

[0034] Comparative Example 4 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: Red phosphorus (washed three times with ethanol in advance and then vacuum-dried at 60°C for later use) and PC material with a mass ratio of 3:1 were fully ground using an agate mortar and placed in a pre-cleaned ampoule tube. A water pump was used to evacuate the ampoule tube to -1 bar, and the tube was sealed at high temperature using a flame gun. The vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature. The ampoule tube was taken out and placed in a glove box, and the ampoule tube was broken open with a glass tube cutter. The red phosphorus carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus carbon composite material RP@PC. S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: 45 mg of the freeze-dried product and 150 mg of RP@PC material were dissolved in 12 mL of deionized water, stirred for 3 h, ultrasonicated for 1 h, and freeze-dried to obtain the organic-coated red phosphorus carbon composite material HT@RP@PC.

[0035] Comparative Example 5 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed 3 times with ethanol in advance and then vacuum-dried at 60°C for later use) and BC material with a mass ratio of 1:1 were fully ground using an agate mortar, placed in a pre-cleaned ampoule tube, and vacuum-sealed using a water pump to reduce the vacuum degree in the ampoule tube to -1 bar. The tube was sealed at high temperature using a flame gun; the vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature; the ampoule tube was taken out and placed in a glove box, and the ampoule tube was broken open using a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC; S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC.

[0036] Comparative Example 6 S1: Wash the burdock root several times with deionized water, then ultrasonically clean it until the washing solution is basically clear; place the treated burdock root in a forced air drying oven and dry it at 90°C for 24 hours; after it is completely dried, grind it with a grinder, sieve it with a 300-mesh sieve, and place the sieved burdock root powder in a 90°C oven to dry for later use; weigh 2g of KOH and place it in 50mL of distilled water, stir it magnetically for 30 minutes, then add 1g of burdock root powder to it, heat it in an 80°C oil bath for 4 hours, collect the precipitate by centrifugation, and place the precipitate in a 90°C oven and air dry it for 12 hours; S2: The burdock root powder pretreated in S1 was fully ground and placed in a porcelain boat, which was then placed in a tube furnace filled with argon gas. The temperature was raised to 800°C at a rate of 5°C / min, kept at that temperature for 2 h, and naturally cooled to room temperature before the material was taken out to obtain biomass carbon material PC; S3: 0.1 g of PC material and 25 mL of 1 M boric acid solution were mixed under ultrasound, and after magnetic stirring for 1 h, the mixed solution of boric acid and PC material was placed in a hydrothermal reactor and hydrothermally reacted at 200 ° C for 5 h. After the reactor was naturally cooled to room temperature, the reaction solution was taken out, the precipitate was collected by centrifugation, washed to neutrality, and dried at 70 ° C for 12 h to obtain boron-doped carbon material BC; S4: Red phosphorus (washed 3 times with ethanol in advance and dried under vacuum at 60°C for later use) and BC material with a mass ratio of 5.5:1 were fully ground using an agate mortar, placed in a pre-cleaned ampoule tube, and vacuumed with a water pump to reduce the vacuum degree in the ampoule tube to -1 bar. The tube was sealed at high temperature using a flame gun; the vacuum-sealed ampoule tube was placed in a quartz tube and calcined under the following reaction conditions: heating to 500°C at a rate of 4°C / min, holding for 4 hours, then cooling to 300°C at a rate of 1°C / min, holding for 24 hours, and naturally cooling to room temperature; the ampoule tube was taken out and placed in a glove box, and the ampoule tube was broken open with a glass tube cutter. The red phosphorus boron-carbon composite material in the ampoule tube was placed in a carbon disulfide solution, white phosphorus was washed off, filtered, washed three times with ethanol by centrifugation, and dried at 70°C for 12 hours to obtain the red phosphorus boron-carbon composite material RP@BC; S5: Weigh 80 mL of distilled water using a measuring cylinder, add 1.95 g of morpholineethanesulfonic acid (MES) to the mixture under magnetic stirring, and stir for 30 min. Add 1 mol / L NaOH solution dropwise to the mixture. Stop the addition when the pH reaches 5.5, add deionized water to 100 mL, and refrigerate to obtain a MES buffer solution with a pH of 5.5 and 0.01 mol / L. Dissolve 1 g (100 kDa, 5 mmol) of hyaluronic acid in 50 mL of the above-prepared MES buffer solution, stir magnetically for 1 h, and then add 1.25 g (20 mmol) of NHS. After 5 min, add 1.915 g (20 mmol) of EDC, and then add 1.31 g (15 mmol) of tyramine. Let the mixture react at room temperature for 72 h, and then freeze-dry at -65°C and 0.1 MPa for 24 h to obtain a tyramine-modified hyaluronic acid freeze-dried product. S6: Dissolve 45 mg of the freeze-dried product and 150 mg of RP@BC material in 12 mL of deionized water, stir for 3 h, ultrasonicate for 1 h, and freeze-dry to obtain the organic-coated red phosphorus boron-carbon composite material HT@RP@BC.

[0037] Test Example 1: Nitrogen adsorption and desorption test Nitrogen adsorption and desorption tests were performed on the composite materials obtained in Examples 1 to 11 and Comparative Examples 1 to 6. The results are shown in Table 1.

[0038] Table 1 Properties of the composite materials obtained in Examples 1 to 11 and Comparative Examples 1 to 6 Application Example 1 (1) Prepare a binder with a PVDF (polyvinylidene fluoride) concentration of 0.05 g / mL: Dissolve 0.4 g of PVDF in 8 mL of N-methylpyrrolidone (NMP) solution in an 80°C water bath and heat for 8 h to obtain the binder; select carbon black as the conductive agent, and the mass ratio of the organic-coated red phosphorus boron-carbon composite material obtained in Example 1, carbon black, and binder is 7:2:1. Place a certain proportion of the organic-coated red phosphorus boron-carbon composite material obtained in Example 1 and carbon black in a mortar and grind them thoroughly. Then place the mixture in a small beaker with a lid, add the binder, and add NMP solution dropwise to make it a uniform viscous material. Then, stir magnetically for 12 h. Then, use a spatula to apply the stirred material to a clean copper foil and dry it with air at 90°C for 12 h.

[0039] (2) The dried copper foil coated with the organic-coated red phosphorus boron carbon composite material obtained in Example 1 was cut into circular electrodes that fit the button battery shell using a cutting machine, and the mass of the material was weighed. The dried positive and negative battery shells, gaskets, and shrapnel washed with ethanol, as well as the dried glass fiber separator, were placed in a glove box together with the cut electrodes to assemble the button battery. The cut electrode coated with the organic-coated red phosphorus boron carbon composite material obtained in Example 1 was used as the negative electrode, and a potassium sheet was selected as the counter electrode in the half-cell. The button half-cell was assembled in the glove box, and the battery was encapsulated and allowed to stand for 12 hours to obtain a battery sample.

[0040] (3) The RP@BC and RP obtained in Example 1 were assembled into batteries according to the method described in steps (1) to (2). The assembled HT@RP@BC batteries, RP@BC batteries and RP batteries were tested for rate performance and cycle performance at a current density of 0.1 A / g. The test results are as follows: Figure 5 and Figure 6 As shown; As can be seen from the figure: the specific capacity of the RP material drops sharply in the early stage of the cycle, while the HT@RP@BC material obtained by the present invention has a higher specific capacity and is relatively stable, with good rate performance and cycle performance.

[0041] 1. If Figure 5 As shown in the graph, the specific capacity of the HT@RP@BC material obtained in the present invention is higher than that of the RP material or the RP@BC material at different current densities. At the same time, the overall capacity decay of the HT@RP@BC material is slower, proving that the HT@RP@BC material obtained in the present invention has better rate performance. 2. If Figure 6As shown in Figure (a), the discharge capacities of the RP material from 0 to 5 cycles are 1450.4 mAh / g, 605.8 mAh / g, 403.8 mAh / g, 207.8 mAh / g, and 104.7 mAh / g, respectively, with a capacity retention rate of 7.2%; the discharge capacities of the RP@BC material from 0 to 5 cycles are 1608.5 mAh / g, 844.6 mAh / g, 625.7 mAh / g, 563.1 mAh / g, and 534.3 mAh / g, respectively, with a capacity retention rate of The rate is 33.2%; the discharge capacity of the HT@RP@BC material from 0 to 5 cycles are 1727.3mAh / g, 1128.3mAh / g, 810.4mAh / g, 703.3mAh / g, and 665.7mAh / g, respectively, with a capacity retention rate of 38.5%; this shows that the HT@RP@BC material has a smaller attenuation degree in the early stage and a higher capacity retention rate; and, under the same number of cycles, the HT@RP@BC material has a better capacity retention rate and better cycle performance.

[0042] Effect Example 1: Cyclic Performance Test The organic-coated red phosphorus boron-carbon composite material obtained in the present invention was assembled into a battery according to the method described in steps (1) to (2) of Preparation Example 1. The obtained battery samples were subjected to cycle performance tests at current densities of 0.1 A / g and 1 A / g, and the test results are shown in Table 2.

[0043] Table 2 Cycling performance of battery samples loaded with organic-coated red phosphorus boron-carbon composite materials obtained in the present invention Although the present invention has been described in detail with reference to the aforementioned embodiments, those skilled in the art may still modify the technical solutions described in the aforementioned embodiments, or make equivalent replacements for some of the technical features therein; and these modifications or replacements do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

Claims

1. An organic-coated red phosphorus boron-carbon composite material, characterized in that: The preparation method comprises: S1: crushing the biomass raw materials and screening them for pretreatment; S2: calcining the pretreated biomass powder to obtain biomass carbon material PC; S3: mixing the PC obtained in step S2 with a boric acid solution and performing a hydrothermal reaction, and the reaction solution is centrifuged, washed, and dried to obtain a boron-doped carbon material BC; S4: vacuum-packaging the red phosphorus and the BC obtained in step S3, and calcining them to obtain a red phosphorus boron-carbon composite material RP@BC; S5: dissolving hyaluronic acid in a morpholineethanesulfonic acid buffer solution, then adding NHS, EDC and tyramine in sequence, reacting them fully at room temperature, and freeze-drying the product to obtain a tyramine-modified hyaluronic acid freeze-dried product; S6: dissolving the freeze-dried product obtained in S5 with RP@BC, reacting them by ultrasonication, and freeze-drying to obtain an organic-coated red phosphorus boron-carbon composite material; The biomass raw materials include one or more of burdock roots, corn silk, pomegranate seeds, corn stalks, orange peels and sun-dried loofah pulp.

2. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The pretreatment in S1 is as follows: weigh potassium hydroxide and place it in water, stir it thoroughly until it dissolves, add biomass raw material powder thereto, treat it at 60-100° C. for 2-6 hours, collect the precipitate by centrifugation, and place it in an oven for forced air drying; the mass ratio of the biomass raw material powder to potassium hydroxide is 1:2-4.

3. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The calcination in S2 is as follows: placing the sample in a tubular furnace under an argon atmosphere, heating the sample from room temperature to 600-1000°C at a rate of 3-8°C / min, keeping the temperature for 1-3 hours, and naturally cooling the sample to room temperature.

4. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The ratio of PC and boric acid used in S3 is 1g:0.1~0.5mol; the hydrothermal reaction in S3 is: placing in a hydrothermal reactor, reacting at 150~250℃ for 3~8h, and naturally cooling to room temperature.

5. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The mass ratio of red phosphorus to BC in S4 is 1.5~4.5:

1.

6. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The calcination in S4 is as follows: heating to 400-600°C at a rate of 3-5°C / min, keeping warm for 3-5 hours, cooling to 200-400°C at a rate of 0.5-1.5°C / min, keeping warm for 18-30 hours, and naturally cooling to room temperature; the vacuum degree of the vacuum packaging in S4 is -1-3 bar.

7. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The molar ratio of morpholineethanesulfonic acid, hyaluronic acid, NHS, EDC and butyric acid in S5 is 0.5:3~8:15~25:15~25:10~20; the concentration of the morpholineethanesulfonic acid buffer solution is 0.01 mol / L, and the pH is 5.

5.

8. The organic-coated red phosphorus boron-carbon composite material according to claim 1, characterized in that: The mass ratio of the freeze-dried product in S6 to RP@BC is 3:8~12.

9. A method for preparing the organic-coated red phosphorus boron-carbon composite material according to any one of claims 1 to 8.

10. Use of the organic-coated red phosphorus boron-carbon composite material according to any one of claims 1 to 8 in the field of potassium ion battery electrode materials.

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