A method and apparatus for predicting sodium-ion battery performance based on asphalt structure.

Abstract

This invention discloses a method and apparatus for predicting the performance of sodium-ion batteries based on the structure of asphalt, belonging to the technical field of sodium-ion battery anode materials. By preparing sodium-ion batteries using various asphalt materials, the degree of substitution of the asphalt is fitted to the low-voltage plateau capacity of the sodium-ion battery to form a line segment. This allows for direct prediction of the low-voltage sodium storage plateau capacity of sodium-ion batteries prepared from the obtained asphalt hard carbon material using the information on the degree of substitution of polycyclic aromatic hydrocarbons in the asphalt-based hard carbon material, the fitted line segment of the closed-pore specific surface area / low-voltage plateau capacity, without the need for performance testing after obtaining hard carbon. The steps are simple, starting from the precursor, providing a new means for predicting the structure and electrochemical sodium storage performance of hard carbon materials.

Description

Technical Field

[0001] This invention belongs to the technical field of sodium-ion battery anode materials, and relates to a method and apparatus for predicting the degree of substitution of pitch-based hard carbon precursors and the low-voltage sodium storage platform capacity. Background Technology

[0002] Carbon anode materials play a crucial role in determining the performance of full cells. Among them, pitch-based hard carbon (HC), with its curved carbon layers and closed-cell structure, is considered one of the most promising anode materials. HC's outstanding low voltage plateau capacity (LPP) plays a key role in improving the output voltage and energy density of full cells. Therefore, developing advanced HC anodes with excellent LPP performance is essential for achieving high-energy-density SIBs.

[0003] The formation mechanism of closed pores in hard carbon (HC) and its impact on LPP performance has become a hot topic in the field of solid-state batteries (SIBs) and faces significant challenges. By adjusting the microcrystalline / amorphous regions of the precursor, stacked carbon layers can be formed in HC, thereby generating closed pores. Pre-oxidation, which induces molecular crosslinking through oxygen functional groups and promotes carbon layer bending to form closed pores, is widely used in the preparation of HC materials with closed-pore structures. Although many studies focus on optimizing carbon precursors through pre-oxidation to achieve closed-pore design and thus improve the low-voltage capacity of HC, existing research lacks methods to directly predict the closed-pore and low-voltage sodium storage performance of hard carbon from the precursor structure.

[0004] Currently, existing technologies cannot directly predict the electrochemical sodium storage performance of hard carbon anodes based on precursor structure, lacking a source-based prediction method for the relationship between precursors, hard carbon, and electrochemical sodium storage performance. Existing technologies lack effective and accurate methods for evaluating low-voltage sodium storage performance, only allowing for rough estimations based on the hard carbon material structure. The complexity of the hard carbon sodium storage mechanism in the low-voltage range makes accurate performance evaluation particularly difficult. Most existing evaluation methods target the high-voltage range, falling short in assessing sodium storage performance in the low-voltage range. Determining whether a precursor can be used to fabricate a hard carbon anode for sodium batteries requires carbonization. Specifically, the sodium storage capacity of hard carbon in the low-voltage range mainly originates from the interlayer insertion and extraction of sodium ions within the graphite microcrystals of the hard carbon material. However, existing evaluation methods often fail to accurately capture this process, leading to significant errors in the evaluation results of low-voltage sodium storage performance. This not only affects a comprehensive understanding of the performance of hard carbon materials but also hinders the further development of sodium-ion battery technology. Summary of the Invention

[0005] The purpose of this invention is to provide a method and apparatus for predicting the performance of sodium-ion batteries based on the structure of asphalt. This method can directly predict the low-pressure sodium storage platform capacity of the obtained hard carbon by utilizing the degree of substitution of polycyclic aromatic hydrocarbon precursors in the asphalt hard carbon material. It eliminates the need to test the performance after obtaining hard carbon from asphalt, thus effectively improving the design efficiency of carbon materials.

[0006] To achieve the above objectives, this invention discloses a method for predicting the performance of sodium-ion batteries based on pitch structure, comprising the following steps:

[0007] 1) After oxidizing various types of asphalt and carbonizing them at high temperature, they are acid-washed and dried to obtain various asphalt-based hard carbon materials for preparing sodium-ion battery anodes.

[0008] 2) Solid-state NMR was used to separate the peaks of various pitch-based hard carbon materials. The degree of substitution of various pitch-based hard carbon materials was calculated by calculating the relative contents of aromatic carbon and aromatic branched carbon. The degree of substitution information of each pitch-based hard carbon material was stored according to the name and the degree of substitution data to generate a dataset of the degree of substitution of pitch-based hard carbon materials.

[0009] 3) Use the various pitch-based hard carbon materials obtained in step 1) to make sodium-ion battery anodes respectively, and then use the made sodium-ion battery anodes to make sodium-ion batteries.

[0010] 4) Electrochemical tests were performed on all the sodium-ion batteries produced to obtain the low-voltage plateau capacity information of each sodium-ion battery, thereby obtaining a dataset of closed-pore specific surface area / low-voltage plateau capacity corresponding to the low-voltage plateau capacity of sodium-ion batteries; among which, the closed-pore specific surface area of ​​pitch-based hard carbon material is positively correlated with the low-voltage plateau capacity.

[0011] 5) Using the dataset of substitution degree of pitch-based hard carbon materials as the x-axis and the dataset of closed-cell specific surface area / low-voltage plateau capacity as the y-axis, linear fitting is performed based on the datasets of substitution degree of pitch-based hard carbon materials and closed-cell specific surface area / low-voltage plateau capacity to obtain the fitted line segment of pitch-based hard carbon materials and closed-cell specific surface area / low-voltage plateau capacity. Using this fitted line segment, the low-voltage plateau capacity of sodium-ion batteries prepared from any pitch-based hard carbon material can be predicted based on the substitution degree of that pitch-based hard carbon material.

[0012] Furthermore, all types of asphalt have a condensed ring structure, including low-temperature coal tar pitch, medium-temperature coal tar pitch, mesophase asphalt, high-temperature coal tar pitch, petroleum asphalt, and coated asphalt; to improve accuracy, multiple asphalt products of the same type produced under different production environments can be selected for measurement.

[0013] Furthermore, the high-temperature oxidation process of asphalt is as follows: the asphalt is oxidized at 300℃ for 3 hours, crushed, screened, and then oxidized at 300℃ for 3 hours again.

[0014] Furthermore, the high-temperature carbonization treatment of asphalt specifically involves carbonizing the asphalt at 1500℃ for 2 hours.

[0015] Furthermore, the original solid-state NMR spectrum was split using Messrenova software to obtain a peak-splitting curve that simulates the original spectrum with three peaks. The relative content was obtained by calculating the integral area enclosed by the peak curves of aromatic carbon and aromatic branched carbon, respectively. The distribution area of ​​aromatic carbon was 90-148 ppm, and the distribution area of ​​aromatic branched carbon was 138-148 ppm.

[0016] Furthermore, the degree of substitution of pitch as a precursor was calculated by measuring the aromatic branched carbon. In aromatic carbon atom I ar The formula is derived from the proportion of the total, and the expression is:

[0017]

[0018] Furthermore, the low-voltage platform capacity is the reversible capacity of the low-voltage platform of the charging curve.

[0019] Furthermore, the specific surface area of ​​the closed-cell hard carbon material was detected using BET and small-angle X-ray scattering (SAXS), and the calculation expression is S. closed pore =S BET -S SAXS .

[0020] Furthermore, during the linear fitting process, it is necessary to ensure that as many data points as possible, used as coordinates, fall on a straight line to reduce errors. The correlation R of the fitted line should be greater than 0.9.

[0021] An apparatus for predicting the performance of sodium-ion batteries from pitch structure, characterized in that it includes a processor and a memory, the processor being electrically connected to the memory, the memory being used to store instructions and data, and the processor being used to execute the prediction method for predicting the performance of sodium-ion batteries from pitch structure as described in any one of claims 1-9; by using the substitution degree data of pitch-based hard carbon materials, the fitting line segment of pitch-based hard carbon materials and closed-pore specific surface area / low voltage plateau capacity, the low voltage plateau capacity of sodium-ion batteries made using pitch-based hard carbon materials is predicted without the need for sample preparation for testing.

[0022] Compared with the prior art, the present invention has the following advantages:

[0023] (1) The present invention is simple and effective. It is based on the research of the precursor substitution degree Δ of polycyclic aromatic hydrocarbon pitch precursor to predict the low voltage sodium storage platform capacity of hard carbon. After obtaining the relative contents of aromatic carbon and aromatic branched carbon by fitting the peaks of solid NMR, the precursor substitution degree of polycyclic aromatic hydrocarbon pitch is calculated, and the low voltage sodium storage platform capacity is predicted from the precursor.

[0024] (2) This invention has made a breakthrough in the field of sodium-ion battery anode material technology. It mainly solves the problem of lacking a method to predict the sodium storage performance of LPP for sodium-ion battery pitch-based hard carbon based on pitch precursors. It provides a new means for efficiently screening pitch precursors and preparing high-performance sodium-ion battery hard carbon anodes. Attached Figure Description

[0025] Figure 1 This is a TEM image of the asphalt numbered HC-1 in Example 1 of the present invention;

[0026] Figure 2 This is a TEM image of the asphalt numbered HC-2 in Example 2 of the present invention;

[0027] Figure 3 This is a TEM image of the asphalt numbered HC-3 in Example 3 of the present invention;

[0028] Figure 4 This is the small-angle X-ray diffraction pattern (SAXS) in an embodiment of the present invention.

[0029] Figure 5 The charge-discharge curves are those of Embodiment 1 of the present invention;

[0030] Figure 6 The charge-discharge curves are those of Embodiment 1 of the present invention;

[0031] Figure 7 The charge-discharge curves are those of Embodiment 1 of the present invention;

[0032] Figure 8 The curves showing the precursor substitution degree Δ-closed-pore specific surface area fitting in Examples 1-6 of this invention;

[0033] Figure 9 The curves showing the precursor substitution degree Δ-LPP fitting curves in Examples 1-6 of this invention. Detailed Implementation

[0034] The embodiments of the present invention will be further described below with reference to the accompanying drawings:

[0035] Example 1

[0036] Low-temperature coal tar pitch was selected as the precursor, labeled P1. The pitch was oxidized at 300℃ for 3 hours, and then again at 300℃ for 3 hours to obtain oxidized pitch (labeled OP1). The oxidized pitch was carbonized in a tube furnace under argon atmosphere at 1500℃ for 2 hours, with a heating rate of 5℃ / min. After carbonization, the carbonized pitch sample (labeled HC-1) was washed in a 1% hydrochloric acid (HCl) solution to remove residual impurities. TEM images are shown below. Figure 1 As shown, the yellow lines represent a structural diagram.

[0037] BET and small-angle X-ray scattering (SAXS) were applied to detect closed-pore structures. HC-1 specific surface area (S BET ) is 5.8m 2 g -1 S SAXS 278m 2 g -1 The calculated closed-cell specific surface area of ​​HC-1 is 272.2 m². 2 g -1 .

[0038] The steps for preparing a sodium-ion battery using the obtained HC-1 are as follows: HC-1, sodium carboxymethyl cellulose, and carbon black were weighed at a mass ratio of 8:1:1, and an appropriate amount of distilled water was added. After ball milling at a rate of 200 r / min for 6 h, copper foil was uniformly coated onto the mixture, and the mixture was vacuum dried at 60 °C for 24 h to obtain the battery electrode. Using the obtained battery electrode as the working electrode and the sodium sheet as the counter electrode, sodium-ion button batteries were assembled in a glove box. Electrochemical performance tests showed that HC-1 exhibited a first-time efficiency of 52%, and its ramp charge-discharge curve plateau capacity was 17 mAh g⁻¹. -1 ,like Figure 5 As shown.

[0039] After obtaining the relative contents of aromatic carbon (90-148 ppm) and aromatic branched carbon (138-148 ppm) in two regions by fitting solid-state NMR peaks, the degree of substitution of the precursor of polycyclic aromatic hydrocarbon asphalt, i.e., aromatic branched carbon, was calculated. In aromatic carbon atoms (I ar The proportion of P1 in the matrix. After peak separation, aromatic branched carbons of P1 were obtained. and aromatic carbon atoms (I ar The relative contents of P1 and P2 are 5.9% and 65.5%, respectively, and the precursor substitution degree of P1 is calculated to be 9%.

[0040] Example 2

[0041] Medium-temperature coal tar pitch was selected as the precursor, labeled P2. The pitch was oxidized at 300℃ for 3 hours, and then again at 300℃ for 3 hours to obtain oxidized pitch (labeled OP2). The oxidized pitch was carbonized in a tube furnace under argon atmosphere at 1500℃ for 2 hours, with a heating rate of 5℃ / min. After carbonization, the carbonized pitch sample (labeled HC-2) was washed in a 1% hydrochloric acid (HCl) solution to remove residual impurities. TEM images are shown below. Figure 2 As shown, the yellow lines represent a structural diagram.

[0042] BET and small-angle X-ray scattering (SAXS) were applied to detect closed-pore structures. HC-2 specific surface area (S BET ) is 4.8m 2 g -1 S SAXS 1196m 2 g -1 The calculated closed-cell specific surface area of ​​HC-2 is 1191.2 m². 2 g -1 .

[0043] The steps for preparing a sodium-ion battery using the obtained HC-2 are as follows: HC-2, sodium carboxymethyl cellulose, and carbon black were weighed at a mass ratio of 8:1:1, and an appropriate amount of distilled water was added. The mixture was ball-milled at 200 r / min for 6 h, then uniformly coated with copper foil. After vacuum drying at 60 °C for 24 h, a battery electrode was obtained. Using the obtained battery electrode as the working electrode and the sodium sheet as the counter electrode, a sodium-ion button cell was assembled in a glove box. Electrochemical performance tests showed that HC-2 exhibited 82% initial efficiency and a plateau capacity as high as 304 mAh g-1; the charge-discharge curves are shown below. Figure 6 As shown.

[0044] After obtaining the relative contents of aromatic carbon (90-148 ppm) and aromatic branched carbon (138-148 ppm) in two regions by fitting solid-state NMR peaks, the degree of substitution of the precursor of polycyclic aromatic hydrocarbon asphalt, i.e., aromatic branched carbon, was calculated. In aromatic carbon atoms (I ar The proportion of P2 in the matrix. After peak separation, aromatic branched carbons of P2 were obtained. and aromatic carbon atoms (I ar The relative contents of P2 and P2 are 16.8% and 70%, respectively. Calculations show that the precursor substitution degree of P2 is 24%.

[0045] Example 3

[0046] Mesophase pitch was selected as the precursor and labeled P3. The pitch was oxidized at 300℃ for 3 hours, and then again at 300℃ for 3 hours to obtain oxidized pitch (labeled OP3). The oxidized pitch was carbonized in a tube furnace under argon atmosphere at 1500℃ for 2 hours at a heating rate of 5℃ / min. After carbonization, the carbonized pitch sample (labeled HC-3) was washed in a 1% hydrochloric acid (HCl) solution to remove residual impurities. TEM images are shown below. Figure 3 As shown, the yellow lines represent a structural diagram.

[0047] BET and small-angle X-ray scattering (SAXS) were applied to detect closed-pore structures. HC-2 specific surface area (S BET ) is 5.0m 2 g -1 S SAXS 525m 2 g -1 The calculated closed-cell specific surface area of ​​HC-2 is 520 m². 2 g -1 .

[0048] The steps for preparing a sodium-ion battery using the obtained HC-3 are as follows: HC-3, sodium carboxymethyl cellulose, and carbon black were weighed at a mass ratio of 8:1:1, and an appropriate amount of distilled water was added. The mixture was ball-milled at 200 r / min for 6 h, then uniformly coated with copper foil. After vacuum drying at 60 °C for 24 h, a battery electrode was obtained. Using the obtained battery electrode as the working electrode and the sodium sheet as the counter electrode, a sodium-ion button cell was assembled in a glove box. Electrochemical performance tests showed that HC-3 exhibited 71% initial efficiency and a plateau capacity of 35 mAh g⁻¹; the charge-discharge curves are shown below. Figure 7 As shown.

[0049] After obtaining the relative contents of aromatic carbon (90-148 ppm) and aromatic branched carbon (138-148 ppm) in two regions by fitting solid-state NMR peaks, the degree of substitution of the precursor of polycyclic aromatic hydrocarbon asphalt, i.e., aromatic branched carbon, was calculated. In aromatic carbon atoms (I ar The proportion of P3 in the matrix. After peak separation, aromatic branched carbons of P3 were obtained. and aromatic carbon atoms (I ar The relative contents of P3 were 9.4% and 87.4%, respectively, and the precursor substitution degree of P3 was calculated to be 11%.

[0050] The small-angle X-ray diffraction (SAXS) patterns of the samples in Examples 1-3 above are specifically as follows: Figure 4 As shown.

[0051] Example 4

[0052] High-temperature coal tar pitch was selected as the precursor, designated P4. The pitch was oxidized at 300℃ for 3 hours, followed by another oxidization at 300℃ for 3 hours to obtain oxidized pitch (designated OP4). The oxidized pitch was carbonized in a tubular furnace under argon atmosphere at 1500℃ for 2 hours at a heating rate of 5℃ / min. After carbonization, the carbonized pitch sample (designated HC-4) was washed in a 1% hydrochloric acid (HCl) solution to remove residual impurities.

[0053] BET and small-angle X-ray scattering (SAXS) were applied to detect closed-pore structures. HC-4 specific surface area (S BET The length is 6.7m 2 g -1 S SAXS It is 618.7m 2 g -1 The calculated closed-cell specific surface area of ​​HC-4 is 612 m². 2 g -1 .

[0054] The steps for preparing a sodium-ion battery using the obtained HC-4 are as follows: HC-2, sodium carboxymethyl cellulose, and carbon black were weighed at a mass ratio of 8:1:1, and an appropriate amount of distilled water was added. After ball milling at a rate of 200 r / min for 6 h, copper foil was uniformly coated onto the mixture, and the mixture was vacuum dried at 60 °C for 24 h to obtain the battery electrode. Using the obtained battery electrode as the working electrode and the sodium sheet as the counter electrode, sodium-ion button batteries were assembled in a glove box. Electrochemical performance tests showed that HC-4 exhibited 73% initial efficiency and a plateau capacity of 78 mAh g⁻¹.

[0055] After obtaining the relative contents of aromatic carbon (90-148 ppm) and aromatic branched carbon (138-148 ppm) in two regions by fitting solid-state NMR peaks, the degree of substitution of the precursor of polycyclic aromatic hydrocarbon asphalt, i.e., aromatic branched carbon, was calculated. In aromatic carbon atoms (I ar The proportion of P4 in the matrix. After peak separation, aromatic branched carbons of P4 were obtained. and aromatic carbon atoms (I ar The relative contents of P4 were 10.9% and 72.8%, respectively, and the precursor substitution degree of P4 was calculated to be 15%.

[0056] Example 5

[0057] Petroleum asphalt was selected as the precursor, designated P5. The asphalt was oxidized at 300℃ for 3 hours, and then again at 300℃ for 3 hours to obtain oxidized asphalt (designated OP5). The oxidized asphalt was carbonized in a tube furnace under argon atmosphere at 1500℃ for 2 hours, with a heating rate of 5℃ / min. After carbonization, the carbonized asphalt sample (designated HC-5) was washed in a 1% hydrochloric acid (HCl) solution to remove residual impurities.

[0058] BET and small-angle X-ray scattering (SAXS) were applied to detect closed-pore structures. HC-5 specific surface area (S BET ) is 7m 2 g -1 S SAXS 796.2m 2 g -1 The calculated closed-cell specific surface area of ​​HC-5 is 789.2 m². 2 g -1 .

[0059] The steps for preparing a sodium-ion battery using the obtained HC-5 are as follows: HC-2, sodium carboxymethyl cellulose, and carbon black were weighed at a mass ratio of 8:1:1, and an appropriate amount of distilled water was added. After ball milling at a rate of 200 r / min for 6 h, copper foil was uniformly coated onto the mixture, and the mixture was vacuum dried at 60 °C for 24 h to obtain the battery electrode. Using the obtained battery electrode as the working electrode and the sodium sheet as the counter electrode, sodium-ion button batteries were assembled in a glove box. Electrochemical performance tests showed that HC-5 exhibited 81% initial efficiency and a plateau capacity of 172 mAh g⁻¹.

[0060] After obtaining the relative contents of aromatic carbon (90-148 ppm) and aromatic branched carbon (138-148 ppm) in two regions by fitting solid-state NMR peaks, the degree of substitution of the precursor of polycyclic aromatic hydrocarbon asphalt, i.e., aromatic branched carbon, was calculated. In aromatic carbon atoms (I ar The proportion of P5 in the matrix. After peak separation, aromatic branched carbons of P5 were obtained. and aromatic carbon atoms (I ar The relative contents of P5 were 13.1% and 76.8%, respectively, and the precursor substitution degree of P5 was calculated to be 17%.

[0061] Example 6

[0062] Asphalt coating was selected as the precursor and labeled P6. The asphalt was oxidized at 300℃ for 3 hours, and then again at 300℃ for 3 hours to obtain oxidized asphalt (labeled OP6). The oxidized asphalt was carbonized in a tube furnace under argon atmosphere at 1500℃ for 2 hours, with a heating rate of 5℃ / min. After carbonization, the carbonized asphalt sample (labeled HC-6) was washed in a 1% hydrochloric acid (HCl) solution to remove residual impurities.

[0063] BET and small-angle X-ray scattering (SAXS) were applied to detect closed-pore structures. HC-6 specific surface area (S6) BET ) is 7.3m 2 g -1 S SAXS 823m 2 g-1 The calculated closed-cell specific surface area of ​​HC-6 is 815.7 m². 2 g -1 .

[0064] The steps for preparing sodium-ion batteries using the obtained HC-6 are as follows: HC-2, sodium carboxymethyl cellulose, and carbon black were weighed at a mass ratio of 8:1:1, and an appropriate amount of distilled water was added. After ball milling at a rate of 200 r / min for 6 h, copper foil was uniformly coated onto the mixture, and the mixture was vacuum dried at 60 °C for 24 h to obtain the battery electrode. Using the obtained battery electrode as the working electrode and the sodium sheet as the counter electrode, sodium-ion button batteries were assembled in a glove box. Electrochemical performance tests showed that HC-2 exhibited a first-time efficiency of 78% and a plateau capacity as high as 213 mAh g⁻¹.

[0065] After obtaining the relative contents of aromatic carbon (90-148 ppm) and aromatic branched carbon (138-148 ppm) in two regions by fitting solid-state NMR peaks, the degree of substitution of the precursor of polycyclic aromatic hydrocarbon asphalt, i.e., aromatic branched carbon, was calculated. In aromatic carbon atoms (I ar The proportion of P6 in the matrix. After peak separation, aromatic branched carbons of P6 were obtained. and aromatic carbon atoms (I ar The relative contents of P6 were 13.8% and 68.9%, respectively, and the precursor substitution degree of P6 was calculated to be 20%.

[0066] like Figure 8 and Figure 9 As shown in Table 1, with the degree of substitution of P1-P6 as the x-axis and the closed-cell specific surface area of ​​samples HC-1, HC-2, HC-3, HC-4, HC-5, and HC-6 / low-voltage plateau capacity (LPP) of sodium-ion batteries as the y-axis, the degree of substitution of pitch-based hard carbon precursors and the closed-cell specific surface area of ​​hard carbon materials / low-voltage sodium storage plateau capacity are fitted and calculated. This allows for the prediction of the low-voltage plateau capacity when pitch-based hard carbon with different degrees of substitution is applied to sodium-ion batteries, and the degree of substitution and low-voltage plateau capacity have a strong linear relationship.

[0067] Table 1 shows the structural parameters of asphalt determined by 13C-CP / MAS-NMR spectroscopy.

[0068]

[0069] Therefore, the prediction method based on polycyclic aromatic hydrocarbon pitch precursors for studying precursor substitution degree (Δ) and low-voltage sodium storage platform capacity of hard carbon is intuitive and reliable, providing a theoretical basis and technical guidance for solving the problem of lacking clear and effective indicators to predict the LPP sodium storage performance of pitch-based hard carbon.

Claims

1. A method for predicting the performance of sodium-ion batteries based on pitch structure, characterized in that, Includes the following steps: 1) Various types of asphalt are oxidized and carbonized at high temperature, and then acid-washed and dried to obtain various asphalt-based hard carbon materials for preparing sodium-ion battery anodes; 2) Solid-state NMR was used to separate the peaks of various pitch-based hard carbon materials. The degree of substitution of various pitch-based hard carbon materials was calculated by calculating the relative contents of aromatic carbon and aromatic branched carbon. The degree of substitution information of each pitch-based hard carbon material was stored according to the name and the degree of substitution data to generate a dataset of the degree of substitution of pitch-based hard carbon materials. 3) Use the various pitch-based hard carbon materials obtained in step 1) to make sodium-ion battery anodes respectively, and then use the made sodium-ion battery anodes to make sodium-ion batteries. 4) Perform electrochemical tests on all the sodium-ion batteries produced to obtain the low-voltage plateau capacity information of each sodium-ion battery, thereby obtaining a dataset of closed-pore specific surface area / low-voltage plateau capacity corresponding to the low-voltage plateau capacity of sodium-ion batteries. Among them, the closed-cell specific surface area and low voltage plateau capacity of pitch-based hard carbon materials are positively correlated; 5) Using the dataset of substitution degree of pitch-based hard carbon materials as the x-axis and the dataset of closed-cell specific surface area / low-voltage plateau capacity as the y-axis, linear fitting is performed based on the datasets of substitution degree of pitch-based hard carbon materials and closed-cell specific surface area / low-voltage plateau capacity to obtain the fitted line segment of pitch-based hard carbon materials and closed-cell specific surface area / low-voltage plateau capacity. Using this fitted line segment, the low-voltage plateau capacity of sodium-ion batteries prepared from any pitch-based hard carbon material can be predicted based on the substitution degree of that pitch-based hard carbon material.

2. The method for predicting sodium-ion battery performance based on pitch structure as described in claim 1, characterized in that, All types of asphalt have a condensed ring structure, including low-temperature coal tar pitch, medium-temperature coal tar pitch, mesophase asphalt, high-temperature coal tar pitch, petroleum asphalt, and coated asphalt. To improve accuracy, multiple asphalt products of the same type produced under different production environments can be selected for measurement.

3. The method for predicting sodium-ion battery performance based on pitch structure as described in claim 1, characterized in that, The high-temperature oxidation process of asphalt is as follows: the asphalt undergoes a first high-temperature oxidation, crushing, screening, and then a second high-temperature oxidation. The first high-temperature oxidation is carried out at 300 ℃ for 3 hours, and the second high-temperature oxidation is carried out at 300 ℃ for 3 hours.

4. The method for predicting sodium-ion battery performance from pitch structure as described in claim 3, characterized in that, The specific process of high-temperature carbonization of asphalt is as follows: carbonize the asphalt at a temperature of 1500 ℃ for 2 hours.

5. The method for predicting sodium-ion battery performance from asphalt structure as described in claim 1, characterized in that, The original solid-state NMR spectrum was fractionated using Mestrenova software to obtain a fractionation curve simulating the original spectrum with three peaks. The relative contents were obtained by calculating the integral area enclosed by the fractionation curves of aromatic carbon and aromatic branched carbon, respectively. The distribution area of ​​aromatic carbon was 90-148 ppm, and the distribution area of ​​aromatic branched carbon was 138-148 ppm.

6. The method for predicting sodium-ion battery performance from asphalt structure as described in claim 1, characterized in that, The degree of substitution of pitch as a precursor was calculated by measuring aromatic branched carbon. In aromatic carbon atom I ar The formula is derived from the proportion of the total, and the expression is: 。 7. The method for predicting sodium-ion battery performance from pitch structure as described in claim 1, characterized in that, The low-voltage plateau capacity is the reversible capacity of the low-voltage plateau of the charging curve.

8. The method for predicting sodium-ion battery performance from pitch structure as described in claim 1, characterized in that, The specific surface area of ​​closed-cell pitch-based hard carbon materials was determined using BET and small-angle X-ray scattering (SAXS), and the calculation expression is S. closed pore =S BET - S SAXS .

9. The method for predicting sodium-ion battery performance from asphalt structure as described in claim 1, characterized in that, The correlation coefficient R of the fitted straight line should be greater than 0.

9.

10. An apparatus for predicting the performance of a sodium-ion battery using the method for predicting the performance of a sodium-ion battery from the pitch structure as described in claim 1, characterized in that, The device includes a processor and a memory, the processor being electrically connected to the memory. The memory is used to store instructions and data, and the processor is used to execute the prediction method for predicting the performance of sodium-ion batteries from the pitch structure as described in any one of claims 1-9. It directly uses the polycyclic aromatic hydrocarbon substitution degree information of the pitch-based hard carbon material, the fitted line segment of the specific surface area of ​​the pitch-based hard carbon material and the low-voltage plateau capacity to directly predict the low-voltage sodium storage plateau capacity of the sodium-ion battery prepared by the obtained pitch hard carbon material, without the need to prepare a sample for testing.

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