Composite carbon negative electrode material prepared from dextrin-asphalt and sodium ion total battery

Abstract

The invention aims to provide a composite carbon negative electrode material prepared from dextrin-asphalt and a sodium ion total battery in order to further improve the electrochemical performance of an asphalt-based carbon material. According to the composite carbon negative electrode material prepared from dextrin-asphalt, dextrin and asphalt are used as reaction raw materials, reactants are mixed, and the carbon negative electrode material is obtained through the processes of high-pressure heat treatment and high-temperature carbonization in sequence. The sodium ion total battery provided by the invention is a sodium ion total battery Na-PDTCNFM composed of a Na-PDTC negative electrode, a nickel iron sodium manganate NFM positive electrode, an electrolyte and a diaphragm. The composite carbon negative electrode material PDTC is low in raw material cost and simple in preparation method, has rich oxygen-containing functional groups and good stability and conductivity, and is matched with a conventional positive electrode material sodium nickel iron manganese oxide NFM to obtain high-energy and long-cycle-life SIBs.

Description

Technical Field

[0001] The present invention belongs to the technical field of sodium ion batteries, and in particular relates to a composite carbon negative electrode material prepared from dextrin-asphalt and a sodium ion full battery. Background Art

[0002] Sodium-ion batteries (SIBs) share the same operating principles as lithium-ion batteries (LIBs), offer safe operation, and are abundant in resources. Therefore, the development of sustainable, low-cost, and high-performance sodium-ion electrochemical energy storage systems is an inevitable trend. Carbon-based materials play a crucial role in SIBs.

[0003] Coal tar pitch, as a coal by-product, has the advantages of low price and high carbon yield, and can be used as a precursor for carbon-based materials. However, coal tar pitch mainly exists in the form of condensed aromatic hydrocarbon structures. During the heat treatment process, their π-π interactions will cause the negative electrode material formed to have ordered oriented graphite layers and small interlayer spacing, which is not conducive to the storage of sodium ions. In order to improve the sodium storage properties of pitch-based carbon materials, the composition and structure of coal tar pitch can be regulated by doping heteroatoms and constructing composite materials. Sun et al. (Journal of Alloys and Compounds, 2019, 786: 468-474) pre-oxidized pitch-based soft carbon and maintained a reversible specific capacity of 190 mAh / g at a current density of 1 C. Wu et al. (Carbon Technology, 2024, 43(4): 48-55, 74) used coal tar pitch as a precursor to prepare sulfur-doped pitch-based carbon microspheres. The prepared material was used as the negative electrode of a sodium ion battery. At a current density of 25 mA / g, the first charge reversible capacity reached 435 mAh / g; at a current density of 0.5 A / g, the reversible capacity was stable at 209 mAh / g. He et al. (New Carbon Materials, 2020, 35(4): 420-427) used coal tar medium-temperature coal tar pitch as a precursor to prepare a sulfur-containing pitch-based carbon material. In a sodium ion battery, the reversible specific capacity in the first charge and discharge cycle was as high as 482 mAh / g. Yang et al. (Chemical Engineering Journal, 2017, 309: 674-681) prepared a composite material of non-expanding reduced graphite oxide and pitch-derived carbon (RGO / C800) as a negative electrode for sodium-ion batteries. According to electrochemical tests, RGO / C800 has a high initial discharge capacity of 268 mAh / g at a current density of 0.02 A / g.

[0004] In order to further improve the electrochemical properties of asphalt-based carbon materials, this patent proposes to use dextrin to regulate the asphalt heat treatment and carbonization process. The resulting material contains a graphite domain structure divided by disordered carbon and rich oxygen-containing functional groups, thereby promoting the electron and ion transmission of asphalt-based carbon materials. Summary of the Invention

[0005] The present invention aims to further enhance the electrochemical performance of pitch-based carbon materials by providing a composite carbon anode material and sodium-ion full battery prepared from dextrin-pitch. The composite carbon anode material, PDTC, utilizes low-cost raw materials, is simple to prepare, and possesses abundant oxygen-containing functional groups, excellent stability, and good conductivity. When paired with conventional positive electrode material, sodium nickel iron manganese oxide (NFM), it enables the production of high-energy, long-cycle-life SIBs.

[0006] One of the technical solutions of the present invention is a composite carbon negative electrode material prepared from dextrin-pitch, referred to as PDTC. The reactants are dextrin and pitch, mixed, and then subjected to high-pressure heat treatment and high-temperature carbonization to obtain the carbon negative electrode material.

[0007] Furthermore, in the above-mentioned composite carbon negative electrode material, the mass ratio of dextrin to asphalt is 0.7:1~2:1.

[0008] Furthermore, in the above-mentioned composite carbon negative electrode material, the asphalt is medium-temperature coal asphalt.

[0009] The second technical solution of the present invention is a method for preparing the composite carbon negative electrode material prepared from dextrin-asphalt, comprising the following steps:

[0010] 1) High pressure heat treatment

[0011] The dextrin and asphalt powder are mixed evenly and placed in a high-pressure reactor with an initial pressure of 2-8 MPa. Under inert gas protection, the reaction is carried out at 350-400 °C for 180-300 minutes. After the reaction, the precursor is obtained by either cooling first and then discharging the steam in the reactor, or discharging the steam in the reactor first and then cooling. The precursor is referred to as PDT.

[0012] Among them, the mass ratio of raw material dextrin to asphalt powder is 0.7:1~2:1;

[0013] 2) High temperature carbonization

[0014] The PDT is dried and ground; then, either directly carbonized under an inert gas atmosphere at a carbonization temperature of 700-850°C for a carbonization time of 1.5-3 hours to obtain PDTC; or the PDT is treated with an alkali, then washed with water, dried, ground, and carbonized under an inert gas atmosphere at a carbonization temperature of 1100-1200°C for a carbonization time of 1.5-3 hours to obtain PDTC.

[0015] The third technical solution of the present invention is a sodium ion full battery, which uses the above-mentioned composite carbon negative electrode material.

[0016] It is a sodium ion full battery Na-PDTC||NFM consisting of a Na-PDTC negative electrode, a sodium nickel iron manganese oxide NFM positive electrode, an electrolyte and a separator;

[0017] Among them, Na-PDTC negative electrode is a PDTC negative electrode made of PDTC as active material and then pre-sodium treatment; NFM positive electrode is made of sodium nickel iron manganese oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 is made of active materials.

[0018] Furthermore, in the above-mentioned sodium ion full battery, the preparation method of the Na-PDTC negative electrode is: mixing PDTC with a conductive agent and a binder, slurrying and grinding evenly, uniformly coating it on a current collector, and then drying and cutting to obtain a PDTC negative electrode, and then performing a pre-sodium treatment to obtain a Na-PDTC negative electrode.

[0019] Furthermore, the pre-sodium treatment method of the above-mentioned sodium ion full battery is: after the PDTC negative electrode is soaked with electrolyte, it is laminated with metallic sodium, left to stand for 20 to 30 minutes, and then the PDTC negative electrode is removed to obtain a Na-PDTC negative electrode.

[0020] Furthermore, the preparation method of the NFM positive electrode of the above-mentioned sodium ion full battery is: mixing NFM with a conductive agent and a binder, slurrying and grinding evenly, uniformly coating it on a current collector, and then drying and cutting to obtain an NFM positive electrode.

[0021] Furthermore, in the above-mentioned sodium ion full battery, the current collector is: either aluminum foil or copper foil.

[0022] Furthermore, in the above-mentioned sodium ion full battery, the diaphragm is glass fiber; and the electrolyte is: either sodium hexafluorophosphate or sodium perchlorate.

[0023] The formation mechanism of the PDTC provided by the present invention is as follows: dextrin, characterized by a high density of hydroxyl groups and linearly dominated short chains, undergoes eutectic, pyrolysis, and polymerization with asphalt in a high-pressure reactor. Initially, the thermally fluid asphalt drives the dextrin into mixing and eutectic, allowing dextrin molecules to penetrate into the asphalt's condensed aromatic regions. During the subsequent high-pressure polycondensation process, the dextrin fragments the asphalt's aromatic regions and, during carbonization, promotes the formation of a disordered structure in the asphalt's hydroxyl-rich environment. Simultaneously, the fragmented aromatic regions evolve into graphite microdomains. The disordered carbon and oxygen-containing functional groups in the product serve as sodium storage, while the graphite domains serve as electron transport.

[0024] Compared with the prior art, the present invention has the following significant advantages:

[0025] 1. The PDTC of the present invention not only forms a disordered carbon segmented graphite domain structure, increasing the disorder degree and interlayer spacing of the carbon material, but also introduces rich oxygen-containing functional groups COC, C=O and -OH, which are conducive to the rapid adsorption of sodium ions and improve the rate performance of the material.

[0026] The reversible specific capacity of the PDTC negative electrode is 255 mAh / g at a current density of 0.1 A / g, and the initial coulombic efficiency is 66.4%. After pre-sodiumization, the PDTC is mixed with conventional sodium nickel iron manganese oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 The O2 cathode material is well matched. The energy density of the sodium-ion full battery Na-PDTC||NFM is approximately 220Wh / kg based on the mass of the positive and negative electrodes.

[0027] 2. The PDTC preparation method provided by the present invention involves dextrin and asphalt undergoing a co-melting, pyrolysis, and polymerization process in a high-pressure reactor. The hydroxyl-rich chain structure of dextrin is utilized to inhibit the orderly rearrangement of asphalt aromatics and introduce abundant oxygen-containing functional groups into the asphalt.

[0028] 3. The full battery of the present invention operates for 1500 cycles at 1 A / g (10 C), and the capacity decays from the initial 142 mAh / g to 75 mAh / g.

[0029] 4. When the full battery of the present invention is evaluated at -15°C, it has a capacity of 120 mAh / g at 0.1 A / g over 100 cycles, and an average coulombic efficiency of 99.4%. When the battery is evaluated at 50°C, it has a capacity of 105 mAh / g at 1 A / g over 400 cycles, and an average coulombic efficiency of 99.8%.

[0030] 5. The full battery of the present invention has the characteristics of high rate, high voltage output, high energy, long cycle life and wide operating temperature range. BRIEF DESCRIPTION OF THE DRAWINGS

[0031] Figure 1 This is a SEM photo of the PDTC material prepared in Example 1 of the present invention.

[0032] Figure 2 This is a HRTEM image of the PDTC material prepared in Example 1 of the present invention.

[0033] Figure 3 This is a graph showing the 1 A / g charge and discharge cycle data of the sodium ion full battery of Example 2 of the present invention.

[0034] Figure 4This is a 0.1 A / g charge and discharge curve of the sodium ion full battery in Example 2 of the present invention.

[0035] Figure 5 This is a graph showing the 0.1 A / g charge and discharge cycle data of a sodium ion full battery in Example 2 of the present invention at -15°C to 0°C.

[0036] Figure 6 This is a graph showing the 1 A / g charge and discharge cycle data of a sodium ion full battery at 50 °C in Example 2 of the present invention.

[0037] Figure 7 This is a graph showing the 0.5 A / g charge and discharge cycle data of the sodium ion full battery of Example 7 of the present invention. DETAILED DESCRIPTION

[0038] In order to make the purpose, technical solutions and advantages of the present invention clearer, the technical solutions of the present invention will be clearly and completely described below in conjunction with the embodiments. The following embodiments are used to illustrate the present invention, but are not intended to limit the scope of the present invention. Based on the embodiments of the present invention, all other embodiments obtained by those of ordinary skill in the art without making creative work are within the scope of protection of the present invention.

[0039] In the following examples, the battery structure described in the present invention is assembled into CR2032 button batteries to describe their electrical performance.

[0040] Example 1

[0041] A composite carbon negative electrode material prepared from dextrin-asphalt, the preparation method of which comprises the following steps:

[0042] (1) High-pressure heat treatment: The asphalt raw material used is medium-temperature coal tar pitch, which is crushed, ground, screened and dried to obtain medium-temperature coal tar pitch powder. The medium-temperature coal tar pitch powder is mixed with dextrin in a mass ratio of 1:1 and then placed in a high-pressure reactor. The initial pressure in the reactor is 6 MPa. Under the protection of N2, the reaction is carried out at a reaction temperature of 380 °C and a reaction time of 240 minutes. After the reaction is completed, it is first cooled and then the steam in the reactor is discharged to obtain PDT;

[0043] (2) Carbonization: PDT was dried and crushed, and then carbonized in a N2 atmosphere at a temperature of 800 °C for 2 h. The carbonized product was cooled and ground to obtain the negative electrode active material PDTC. Figure 1 Medium SEM showed that PDTC was in homogeneous block shape with sharp edges and neat cross section. Figure 2 Medium HRTEM shows that the main body of PDTC is composed of irregularly curved carbon layers with no obvious stacking area, showing a typical highly disordered chaotic layer structure. In addition, it is also interspersed with graphite domain structures, which present 3-4 layers of layered stacked graphitized units with disordered orientation between units.

[0044] Electrochemical performance test of PDTC:

[0045] (1) Preparation of PDTC negative electrode: PDTC material, conductive agent acetylene black, and binder polyvinylidene fluoride (PVDF) were mixed in a mass ratio of 70:15:15, slurried with solvent N-methylpyrrolidone (NMP), ground evenly, and coated on aluminum foil with a coater. The coated negative electrode sheet was dried under vacuum at 120 °C for 12 hours and then cut into PDTC negative electrodes with a diameter of 12 mm.

[0046] (2) Assembly of the PDTC half-cell: In an argon-filled glove box, a sodium metal block was punched into a sodium sheet with a diameter of 14 mm and a thickness of approximately 0.5 mm. This sheet was then assembled with the PDTC negative electrode to form a half-cell. The separator was a glass fiber separator, and the electrolyte used was a 1 M NaClO4 solution consisting of NaClO4 dissolved in a mixture of EC:DMC with a volume ratio of 1:1. EC was ethylene carbonate, and DMC was dimethyl carbonate. The half-cell assembly order was: negative electrode shell, sodium sheet, separator, electrolyte, PDTC negative electrode, gasket, spring, and positive electrode shell. After the PDTC half-cell was left to stand for 12 hours, its electrochemical performance was tested. The negative electrode had a reversible specific capacity of 255 mAh / g at a current density of 0.1 A / g, and an initial coulombic efficiency of 66.4%.

[0047] Example 2

[0048] A sodium ion full battery, using the composite carbon negative electrode material obtained by pyrolysis of dextrin and pitch in Example 1, is a full battery consisting of a Na-PDTC negative electrode, an NFM positive electrode, an electrolyte, and a separator.

[0049] The diaphragm is a glass fiber diaphragm, and the electrolyte used is a 1 M NaClO4 electrolyte formed by dissolving NaClO4 in a mixture with a volume ratio of EC:DMC=1:1;

[0050] Preparation of PDTC negative electrode: The method is the same as that of the electrochemical performance test of PDTC in Example 1 (1) Preparation of PDTC negative electrode.

[0051] Preparation of the Na-PDTC anode: In an argon-filled glove box, a sodium metal block was punched into a 14 mm diameter, approximately 0.5 mm thick sodium sheet. The sodium metal was then bonded to the active material of the PDTC anode. After immersion in an electrolyte for 30 minutes, the PDTC anode was removed to obtain the Na-PDTC anode. The electrolyte used was a 1 M NaClO₄ solution consisting of NaClO₄ dissolved in a 1:1 volume ratio of EC:DMC (ethylene carbonate) and DMC (dimethyl carbonate).

[0052] Preparation of NFM positive electrode: NFM, acetylene black and PVDF were mixed in a mass ratio of 80:10:10, ground evenly with a slurry, and coated on aluminum foil using a coater. The coated positive electrode sheet was dried in a vacuum at 120 °C for 12 hours and then cut into NFM positive electrodes with a diameter of 16 mm.

[0053] Composition of the full-cell Na-PDTC||NFM: The battery assembly order is: negative electrode shell, Na-PDTC negative electrode, separator, electrolyte, NFM positive electrode sheet, gasket, shrapnel, positive electrode shell. It is assembled into a CR2032 button cell in an argon-protected glove box. After the battery is assembled, it is left to stand for 12 hours before the electrochemical performance test.

[0054] The cycling performance of sodium ion battery materials at a current density of 1 A / g for 1500 cycles is shown in Figure 3 , 0.1 A / g current density charge and discharge curves are shown in Figure 4 .

[0055] The sodium-ion full battery has a capacity of 120 mAh / g at 0.1 A / g (10 C) after 1500 cycles, with an average coulombic efficiency of 97% and an energy density of 220 Wh / kg (calculated based on the total mass of the active materials in the negative and positive electrodes). When the battery was evaluated at -15 °C-0 °C, it had a capacity of 120 mAh / g at 0.1 A / g for 100 cycles, with an average coulombic efficiency of 99.4%. The charge and discharge capacity data of the sodium-ion full battery at -15 °C-0 °C is shown in the figure. Figure 5 When the battery was evaluated at 50°C, it had a capacity of 105 mAh / g at 1 A / g over 400 cycles, with an average coulombic efficiency of 99.8%. See the charge and discharge capacity data of the sodium ion full battery at 50°C for details. Figure 6 .

[0056] Example 3

[0057] A composite carbon negative electrode material prepared from dextrin-asphalt is prepared by the same method as in Example 1, except that during the high-pressure heat treatment, the temperature in the autoclave is 350° C. and the pressure is 2 MPa.

[0058] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0059] The composition of the full battery is the same as that of Example 2. The full battery has a higher initial discharge capacity of 203 mAh / g at 0.1 A / g, which decays to 144 mAh / g after 100 cycles, and the average coulombic efficiency remains at 98.4%.

[0060] Example 4

[0061] A composite carbon negative electrode material prepared from dextrin-asphalt is prepared by the same method as in Example 1, except that during the carbonization process, the carbonization temperature is 700° C. and the carbonization time is 3 hours.

[0062] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0063] The composition of the full battery is the same as that of Example 2. The full battery has a high initial discharge capacity of 173 mAh / g at 0.1 A / g, which decays to 160.2 mAh / g after 100 cycles, and the average coulombic efficiency remains at 98.9%.

[0064] Example 5

[0065] A composite carbon negative electrode material prepared from dextrin-asphalt is prepared by the same method as in Example 1, except that during the high-pressure heat treatment, after the reaction is completed, the steam in the kettle is first discharged and then cooled.

[0066] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0067] The composition of the full battery is the same as that of Example 2. The full battery has a high initial discharge capacity of 202 mAh / g at 0.1 A / g, which decays to 176.3 mAh / g after 100 cycles, and the average coulombic efficiency remains at 98.8%.

[0068] Example 6

[0069] A composite carbon negative electrode material prepared from dextrin-asphalt, the preparation method is the same as that in Example 1, except that: during the high-pressure heat treatment process, the mass ratio of dextrin and medium-temperature coal tar powder is 0.75:1, and the other processes are the same as those in Example 1.

[0070] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0071] The composition of the full battery is the same as that of Example 2. The full battery has a high initial discharge capacity of 174.2 mAh / g at 0.1 A / g, which decays to 142.1 mAh / g after 100 cycles, and the average coulombic efficiency remains at 99.8%.

[0072] Example 7

[0073] A composite carbon negative electrode material prepared from dextrin-pitch is prepared using the same method as in Example 1, except that in step 2), the PDT product obtained by high-pressure heat treatment is mixed with an alkaline solution in a mass ratio of 1:2, placed in a hydrothermal reactor, and reacted at 180°C for 24 hours. The alkaline solution is a mixture of KOH dissolved in water and ethanol, with the mass ratio of KOH, water, and ethanol being 9:20:10. The reacted PDT is then washed with water, dried, and carbonized under a nitrogen atmosphere at 1200°C for 2 hours.

[0074] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0075] The composition of the full battery is the same as that of Example 2, and the test results of the full battery are shown in Figure 7 , the average discharge capacity is 141.9 mAh / g at 0.5 A / g, and the average Coulombic efficiency remains at 99.8%.

[0076] Comparative Example 1

[0077] A carbon negative electrode material is prepared by directly carbonizing medium-temperature coal tar powder using the same carbonization method as in Example 1.

[0078] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0079] The battery assembly process was the same as in Example 2. The full battery had an initial discharge capacity of 176 mAh / g at 0.1 A / g, which decayed to 67 mAh / g after 100 cycles.

[0080] Comparative Example 2

[0081] A carbon negative electrode material. When preparing the negative electrode material, dextrin is directly carbonized. The carbonization method is the same as that in Example 1.

[0082] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0083] The battery assembly process was the same as in Example 2. The full battery had an initial discharge capacity of 110 mAh / g at 0.1 A / g, which decayed to 102 mAh / g after 100 cycles.

[0084] Comparative Example 3

[0085] A carbon negative electrode material. When preparing the negative electrode material, only medium-temperature coal tar powder is used as raw material, and the high-pressure heat treatment and carbonization process are the same as in Example 1.

[0086] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0087] The battery assembly process was the same as in Example 2. The full battery had an initial discharge capacity of 182 mAh / g at 0.1 A / g, which decayed to 77 mAh / g after 100 cycles.

[0088] Comparative Example 4

[0089] A carbon negative electrode material and a sodium ion full battery. When preparing the negative electrode material, only dextrin is used as the raw material, and the high-pressure heat treatment and carbonization process are the same as in Example 1.

[0090] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0091] The battery assembly process was the same as in Example 2. The full battery had an initial discharge capacity of 131 mAh / g at 0.1 A / g, which decayed to 109 mAh / g after 100 cycles.

[0092] Comparative Example 5

[0093] A carbon negative electrode material is prepared by uniformly mixing medium-temperature coal tar powder and dextrin in a mass ratio of 1:1 and then directly carbonizing the mixture. The carbonization process is the same as that in Example 1, except that the carbonization temperature is 1200°C.

[0094] The electrochemical performance test results of the full battery of this embodiment are as follows:

[0095] The battery assembly process was the same as in Example 2. The full battery had a high initial discharge capacity of 116 mAh / g at 0.1 A / g, which decayed to 90.3 mAh / g after 100 cycles.

Claims

1. A composite carbon negative electrode material prepared from dextrin-asphalt, referred to as PDTC, characterized in that: The reaction raw materials are dextrin and asphalt. The reactants are mixed and sequentially subjected to high-pressure heat treatment and high-temperature carbonization processes to obtain a carbon negative electrode material.

2. The composite carbon negative electrode material prepared from dextrin-asphalt according to claim 1, characterized in that: The mass ratio of dextrin to asphalt is 0.7:1~2:

1.

3. The composite carbon negative electrode material prepared from dextrin-asphalt according to claim 1, characterized in that: The asphalt is medium-temperature coal tar.

4. The method for preparing a composite carbon negative electrode material prepared from dextrin-asphalt according to claim 1, characterized in that: The steps include: 1) High pressure heat treatment The dextrin and asphalt powder are mixed evenly and placed in a high-pressure reactor with an initial pressure of 2-8 MPa. Under inert gas protection, the reaction is carried out at 350-400 °C for 180-300 minutes. After the reaction, the precursor is obtained by either cooling first and then discharging the steam in the reactor, or discharging the steam in the reactor first and then cooling. The precursor is referred to as PDT. Among them, the mass ratio of raw material dextrin to asphalt powder is 0.7:1~2:1; 2) High temperature carbonization The PDT is dried and ground; then, either directly carbonized under an inert gas atmosphere at a carbonization temperature of 700-850°C for a carbonization time of 1.5-3 hours to obtain PDTC; or the PDT is treated with an alkali, then washed with water, dried, ground, and carbonized under an inert gas atmosphere at a carbonization temperature of 1100-1200°C for a carbonization time of 1.5-3 hours to obtain PDTC.

5. A sodium ion full battery, using the composite carbon negative electrode material according to claim 1, characterized in that: It is a sodium ion full battery Na-PDTC||NFM consisting of a Na-PDTC negative electrode, a sodium nickel iron manganese oxide NFM positive electrode, an electrolyte and a separator; Among them, Na-PDTC negative electrode is a PDTC negative electrode made of PDTC as active material and then pre-sodium treatment; NFM positive electrode is made of sodium nickel iron manganese oxide NaNi 1 / 3 Fe 1 / 3 Mn 1 / 3 O2 is made of active materials.

6. A sodium ion full battery according to claim 5, characterized in that: The preparation method of the Na-PDTC negative electrode comprises: mixing PDTC with a conductive agent and a binder, slurrying and grinding the mixture uniformly, uniformly coating the mixture on a current collector, drying the mixture, cutting the mixture to obtain a PDTC negative electrode, and then performing a pre-sodium treatment to obtain a Na-PDTC negative electrode.

7. A sodium ion full battery according to claim 5 or 6, characterized in that: The pre-sodium treatment method is as follows: after soaking the PDTC negative electrode with electrolyte, it is laminated with metallic sodium, left to stand for 20 to 30 minutes, and then the PDTC negative electrode is removed to obtain a Na-PDTC negative electrode.

8. A sodium ion full battery according to claim 5, characterized in that: The preparation method of the NFM positive electrode is as follows: NFM is mixed with a conductive agent and a binder, slurried and ground evenly, and then evenly coated on a current collector, and then dried and cut to obtain the NFM positive electrode.

9. A sodium ion full battery according to claim 6 or 8, characterized in that: The current collector is either aluminum foil or copper foil.

10. A sodium ion full battery according to claim 5, characterized in that: The diaphragm is glass fiber; the electrolyte is: either sodium hexafluorophosphate or sodium perchlorate.

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