Preparation method of p-ov-in2o3 nanospheres and application thereof in lithium-sulfur battery separators
By using phosphorus-doped and oxygen-defective In2O3 nanospheres in the lithium-sulfur battery separator, the problem of the Li2Sn shuttle effect was solved, and the high efficiency of the lithium-sulfur battery cycle performance and capacity retention were achieved.
Patent Information
- Application Number
- CN202310662880.8
- Authority / Receiving Office
- CN · China
- Patent Type
- Patents(China)
- Current Assignee / Owner
- Filing Date
- 2023-06-06
- Publication Date
- 2025-12-30
- Estimated Expiration
- 2043-06-06
AI Technical Summary
The shuttle effect of Li2Sn in lithium-sulfur batteries leads to the loss of active materials and the decay of battery capacity. Existing carbon-based materials have weak physical adsorption of Li2Sn, making it difficult to effectively suppress the shuttle effect.
Phosphorus-doped and oxygen-deficient In2O3 nanospheres were used as the separator material for lithium-sulfur batteries. The shuttle of Li2Sn was inhibited through chemical adsorption and catalysis, thereby improving the electron conduction rate.
It effectively suppresses the shuttle effect of Li2Sn, improves the cycle performance and coulombic efficiency of lithium-sulfur batteries, and maintains a discharge specific capacity of 564mAh g-1 after 500 cycles at 1.0C, with a capacity decay rate of only 0.069%.
Smart Images
Figure CN116812968B_ABST
Abstract
Description
Technical Field
[0001] This invention relates to the field of lithium-sulfur battery technology, and in particular to a method for preparing P-Ov-In2O3 nanospheres and their application in lithium-sulfur battery separators. Background Technology
[0002] With the depletion of fossil fuels and the rise of green energy, lithium-sulfur batteries have become increasingly popular due to their high capacity (1675mAh g / g). -1 Energy density (2600Wh / kg) -1 This makes it the most energy-storing material. Secondly, thanks to the abundant storage of elemental sulfur and its pollution-free nature, lithium-sulfur batteries possess unparalleled commercial value and application prospects in the development of future chemical power sources. However, lithium-sulfur batteries still face many challenges, such as volume expansion during charging and discharging, poor conductivity of sulfur and lithium sulfide (Li₂S), and the presence of polysulfides (Li₂S₃). n The shuttle effect (4≤n≤8) leads to short cycle life and low coulombic efficiency in lithium-sulfur batteries. Among these, the most serious problem is the Li₂S… n The shuttle effect, in the chemical reaction process of lithium-sulfur batteries, soluble Li₂S n It can pass through the polypropylene membrane, causing loss of active material. Furthermore, when Li2S... n When it shuttles towards the negative electrode, some Li2S n Direct reaction with metallic lithium results in excessive reduction to Li2S on the lithium surface, leading to severe capacity degradation in the battery. Therefore, suppressing the shuttle effect is crucial for lithium-sulfur batteries to fully realize their advantages.
[0003] An effective solution to suppress the shuttle effect is to control the Li2S content during battery charging and discharging. n Physical limitations and chemical adsorption / catalysis reduce Li2S n The shuttle effect can be suppressed to improve battery performance. Currently, many carbon-based materials, such as carbon nanotubes, graphene, and porous carbon, have been reported. However, due to Li₂S… n Li₂S₂ is chemically polar, while carbon materials are nonpolar; the physical adsorption between them is weak and cannot effectively suppress the shuttle effect. Unlike nonpolar carbon materials, polar materials (such as metal oxides, sulfides, nitrides, and carbides) have been shown to inhibit the shuttle effect in Li₂S₂. n It exhibits strong chemical adsorption and catalytic conversion capabilities. The surface of the metal oxide contains hydrophilic functional groups, and the polar chemical bonds between the metal cations and oxygen anions provide sufficient polar active sites to anchor Li₂S. nIn this process, metal oxides possess advantages unmatched by other materials. In₂O₃, as a metal oxide, not only has low resistivity but also high catalytic activity, making it widely used in lithium-sulfur batteries. In₂O₃ can accelerate the kinetics of sulfur redox reactions and suppress the shuttle effect, thereby improving battery performance. Recent studies have shown that defect engineering can disrupt the charge balance state of the crystal surface, effectively exposing active sites. Furthermore, compared to defect-free environments, the electrons surrounding defects are highly reactive and can act as Li₂S... n The adsorption and catalytic sites in In2O3 accelerate the conversion of S8 to Li2S, thereby improving the electrochemical performance of lithium-sulfur batteries. Therefore, introducing defects into In2O3 can alter the electronic states, thus limiting the conversion of Li2S to Li2S. n and accelerating Li2S n The transformation of In2O3 provides an opportunity. However, there are few reports on the engineering of defects in In2O3. Therefore, the synthesis of defective In2O3 is of great significance for the development of high-performance lithium-sulfur batteries. Summary of the Invention
[0004] The purpose of this invention is to provide a method for preparing P-Ov-In2O3 nanospheres and their application in lithium-sulfur battery separators. In2O3 nanospheres containing both phosphorus doping and oxygen defects are synthesized, making them suitable as a material for modifying separators. Due to the introduction of oxygen defects and phosphorus doping, they exhibit strong chemical adsorption / catalytic ability for Li2Sn and improve electron conduction rate.
[0005] To achieve the above objectives, this invention provides a method for preparing P-Ov-In2O3 nanospheres and their application in lithium-sulfur battery separators, comprising the following steps:
[0006] S1. Add In(NO3)3·2H2O to the glass bottle containing ethylene glycol and stir magnetically until the solution is clear and transparent;
[0007] S2. Then, the glass bottle containing the solution obtained in step S1 is placed in the liner of the reaction vessel containing hypophosphite, and the reaction vessel is placed in a forced-air drying oven to react and obtain P-Ov-In2O3NSs precipitate.
[0008] S3. Finally, the P-Ov-In2O3NSs precipitate was washed three times with deionized water and anhydrous ethanol, and then dried in a forced-air drying oven at 50°C for 24 hours to obtain P-Ov-In2O3NSs nanospheres.
[0009] Preferably, the ratio of ethylene glycol to hypophosphite is 7:6.
[0010] Preferably, in step S1, the addition of In(NO3)3·2H2O to the glass bottle containing ethylene glycol is 40 mg of In(NO3)3·2H2O per 7 mL of ethylene glycol.
[0011] Preferably, in step S2, the reaction temperature is 200°C and the reaction time is 6 hours.
[0012] This invention also provides an application of P-Ov-In2O3 nanospheres in lithium-sulfur battery separators.
[0013] Preferably, it includes the following steps:
[0014] (1) Preparation of P-Ov-In2O3NSs modified membrane;
[0015] (2) Preparation of positive electrode sheet;
[0016] (3) Assemble the battery.
[0017] Preferably, in step (1), the P-Ov-In2O3NSs modified membrane includes: placing P-Ov-In2O3NSs nanospheres, acetylene black and polyvinylidene fluoride in a glass bottle at a mass ratio of 8:1:1, and magnetically stirring for 12 hours to obtain a mixed slurry.
[0018] The mixed slurry was coated onto the diaphragm to obtain a P-Ov-In2O3NSs modified diaphragm;
[0019] The obtained P-Ov-In2O3NSs modified diaphragm was dried in a 50℃ forced-air drying oven for 1 hour and then transferred to a 50℃ vacuum drying oven for 12 hours. It was then cut into circular diaphragm sheets with a diameter of 16 mm.
[0020] Preferably, in step (2), the preparation of the positive electrode sheet includes: grinding S and CNTs thoroughly at a mass ratio of 4:1 and then drying to obtain S-CNTs powder;
[0021] S-CNTs powder, acetylene black and polyvinylidene fluoride were mixed in a mass ratio of 8:1:1, then coated onto carbon-coated aluminum foil and dried at 50°C. After drying, the mixture was cut into 12mm diameter S-CNTs circular positive electrode sheets.
[0022] Preferably, in step (3), the battery assembly includes: being carried out in an argon glove box, using a lithium metal sheet as the negative electrode, an S-CNTs circular positive electrode sheet as the positive electrode, and a P-Ov-In2O3NSs modified separator as the separator, with the following corresponding proportions of the required electrolyte components: the volume ratio of DOL to DME is 1:1, the concentration of LiTFSI is 1M, and the concentration of LiNO3 is 0.1M.
[0023] Therefore, the present invention employs the above-mentioned method for preparing P-Ov-In2O3 nanospheres and their application in lithium-sulfur battery separators, and its technical effects are as follows:
[0024] (1) The introduction of oxygen defects disrupts the charge balance on the crystal surface, changes the electronic state, provides efficient active sites for Li2Sn, and accelerates the conversion of Li2Sn.
[0025] (2) Phosphorus doping accelerates ion diffusion kinetics and improves the conductivity of the material.
[0026] (3) The P-Ov-In2O3 / / PP battery exhibited excellent cycle performance in electrochemical performance testing, maintaining a discharge specific capacity of 564 mAh g⁻¹ after 500 cycles at 1.0C. -1 Moreover, the capacity decay rate per revolution is only 0.069%.
[0027] The technical solution of the present invention will be further described in detail below with reference to the accompanying drawings and embodiments. Attached Figure Description
[0028] Figure 1 A schematic diagram of the synthesis of P-Ov-In2O3NSs;
[0029] Figure 2 The image shows the morphological characterization results of P-Ov-In2O3NSs using scanning electron microscopy (SEM) and transmission electron microscopy (TEM).
[0030] (a) is a SEM image of P-Ov-In2O3NSs, (b) is a TEM image of P-Ov-In2O3NSs, (c) is a TEM image of a single P-Ov-In2O3NS, (d) is an HRTEM image of P-Ov-In2O3NSs, and (eh) is an elemental distribution map of a single P-Ov-In2O3NS.
[0031] Figure 3 The diagram shows the results of characterizing the structure and valence state of P-Ov-In2O3NSs using X-ray diffraction (XRD) and X-ray photoelectron spectroscopy (XPS), and the results of characterizing the sulfur content of S-CNTs using thermogravimetric analysis (TGA).
[0032] (a) is the XRD spectrum of P-Ov-In2O3NSs, (b) is the full spectrum of P-Ov-In2O3NSs, (c) is the fine spectrum of In 3d, (d) is the fine spectrum of O1s, (e) is the fine spectrum of P 2p, and (f) is the TGA curve of S-CNTs.
[0033] Figure 4Characterization figures for lithium sulfide deposition, symmetric cells, charge-discharge curves, and rate performance of batteries assembled using P-Ov-In2O3NSs-modified separators and unmodified PP films.
[0034] (a) is the constant potential discharge curve of PP and P-Ov-In2O3 / / PP battery, (b) is the CV curve of symmetrical electrode of PP and P-Ov-In2O3 / / PP battery, (c) is the charge and discharge curve of PP and P-Ov-In2O3 / / PP battery at 0.1C (ΔE is the polarization potential, Q1 and Q2 are the relevant capacities of two typical plateaus), (d, e) are the corresponding values of ΔE and Q2 / Q1 obtained from the charge and discharge curves, (f, g) are magnified views of the corresponding parts of the charge and discharge curves, (h) is the rate performance diagram of PP and P-Ov-In2O3 / / PP battery, and (i) is the charge and discharge curve of P-Ov-In2O3 / / PP battery at different current densities;
[0035] Figure 5 Characterization figures of the cycle performance and device lighting results of batteries assembled using P-Ov-In2O3NSs modified separators and unmodified PP films;
[0036] (a) is a PP and P-Ov-In2O3 / / PP battery at 1.0 mg cm⁻¹ -2 Sulfur surface loading, coulombic efficiency at 1.0C and cycle performance, (b) is the P-Ov-In2O3 / / PP battery at 4.5 mg cm⁻¹ -2 Sulfur surface loading, coulombic efficiency at 0.2C and cycle performance, (c) is an image of an LED light illuminating the "2023" mark. Detailed Implementation
[0037] The technical solution of the present invention will be further described below with reference to the accompanying drawings and embodiments.
[0038] Unless otherwise defined, the technical or scientific terms used in this invention shall have the ordinary meaning as understood by one of ordinary skill in the art to which this invention pertains.
[0039] It will be apparent to those skilled in the art that the present invention is not limited to the details of the exemplary embodiments described above, and that the invention can be implemented in other specific forms without departing from its spirit or essential characteristics. Therefore, the embodiments should be considered illustrative and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, all variations falling within the meaning and scope of equivalents of the claims are intended to be included within the present invention, and no reference numerals in the claims should be construed as limiting the scope of the claims.
[0040] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and the technical solutions in each embodiment can be appropriately combined to form other embodiments that can be understood by those skilled in the art. These other embodiments are also covered within the scope of protection of this invention.
[0041] It should also be understood that the specific embodiments described above are only used to explain the present invention, and the scope of protection of the present invention is not limited thereto. Any equivalent substitutions or modifications made by those skilled in the art within the scope of the technology disclosed in the present invention, based on the technical solution and inventive concept of the present invention, should be covered within the scope of protection of the present invention.
[0042] Techniques, methods, and apparatus known to those skilled in the art may not be discussed in detail, but where appropriate, they should be considered part of the specification.
[0043] All prior art documents cited in this specification are incorporated herein by reference in their entirety and are therefore part of the disclosure of this invention.
[0044] Example 1
[0045] Preparation of P-Ov-In2O3NSs
[0046] In a glass bottle, 40 mg of In(NO3)3·2H2O and 7 mL of ethylene glycol were added sequentially, and the mixture was magnetically stirred until the solution became clear and transparent. The glass bottle containing the solution was then placed in a 50 mL polytetrafluoroethylene (PTFE) reactor lined with 6 mL of hypophosphite. The reactor was placed in a forced-air drying oven and reacted at 200 °C for 6 hours. Finally, P-Ov-In2O3NSs precipitate was obtained. The precipitate was washed three times with deionized water and anhydrous ethanol, and then dried in a forced-air drying oven at 50 °C for 24 hours to obtain P-Ov-In2O3NSs powder.
[0047] The morphology of the prepared material was studied using cold field emission scanning electron microscopy (SEM) and transmission electron microscopy (TEM). X-ray diffraction (XRD) was used to analyze the phase composition of the prepared material. Elemental analysis was performed using X-ray photoelectron spectroscopy (XPS). Thermogravimetric analysis (TGA) was used to determine the sulfur content.
[0048] The morphology of P-Ov-In2O3NSs was characterized using scanning electron microscopy (SEM) and transmission electron microscopy (TEM). Figure 2 a and Figure 2Images b are SEM and TEM images of P-Ov-In2O3NSs, respectively. It can be seen that P-Ov-In2O3NSs are composed of countless individual P-Ov-In2O3NSs, exhibiting a uniform spherical morphology with a largely intact structure and a diameter of approximately 150 nm. A magnified view of a single P-Ov-In2O3NS in image b is shown below. Figure 2 As shown in Figure c, after the hydrothermal reaction, single P-Ov-In2O3NS are obtained. From Figure 2 Clear lattice fringes can be observed in the HRTEM of d, with a lattice spacing of approximately 0.291 nm, corresponding to the (222) crystal plane of P-Ov-In2O3. Furthermore, Figure 2 (eh) shows the elemental distribution of a single P-Ov-In2O3NS element, indicating that In, O, and P elements coexist and are uniformly distributed, demonstrating that P is uniformly doped in the material.
[0049] like Figure 3 As shown in Figure a, P-Ov-In2O3NSs was tested by X-ray diffraction (XRD) to verify its crystal structure. All diffraction peaks of P-Ov-In2O3NSs belong to the cubic crystal system and correspond to the standard PDF card (PDF#06-0416). The upper right corner is a comparison of the diffraction peaks corresponding to the (222) crystal plane with the standard card. It can be seen that the diffraction peak positions of P-Ov-In2O3NSs have not changed much compared to the standard card, but its diffraction peaks have shifted to higher angles, which is due to bulk P doping. In addition, there are no other impurity peaks, indicating that P-Ov-In2O3NSs has a high-purity crystal structure. The surface chemical composition and elemental valence of the synthesized P-Ov-In2O3NSs were further studied using X-ray photoelectron spectroscopy (XPS). Figure 3 The XPS full spectrum showed the characteristic peaks and binding energies of In 3d, O 1s, P 2p, and C 1s, indicating that only In, O, and P exist in the composite material. From... Figure 3 The fine spectrum of In 3d in c shows two peaks at 444.1 eV and 451.7 eV, corresponding to In 3d, respectively. 5 / 2 and In 3d 3 / 2 This indicates that In is in a trivalent oxidation state. Figure 3 The fine spectral peak of O1s in d is divided into two characteristic peaks, corresponding to O in P-Ov-In2O3, respectively. L (528.85eV) and O V (531.3 eV) proves the existence of oxygen vacancies. Since oxygen vacancies reduce the number of electrons, they weaken the electron shielding effect, ultimately resulting in a change in binding energy. Figure 3 The two peaks at 132.92 eV and 132.10 eV correspond to P 2p, respectively. 1 / 2and P 2p 3 / 2 Previous reports indicate that this peak confirms the formation of PO. To determine the sulfur content in the sample, thermogravimetric analysis (TGA) was performed on the S-CNTs. Figure 3 As can be seen from f, the sulfur content of S-CNTs is 80%.
[0050] Preparation of P-Ov-In2O3NSs modified membrane
[0051] The above-mentioned P-Ov-In2O3NSs powder, acetylene black (SuperP), and polyvinylidene fluoride (PVDF) were placed in a glass bottle at a mass ratio of 8:1:1 and magnetically stirred for 12 hours to obtain a mixed slurry. This slurry was then coated onto a diaphragm, resulting in a modified diaphragm, denoted as P-Ov-In2O3 / / PP. After drying in a 50°C forced-air drying oven for 1 hour, the diaphragm was transferred to a 50°C vacuum drying oven and dried for 12 hours. Finally, it was cut into circular diaphragm sheets with a diameter of 16 mm for later use.
[0052] Preparation of positive electrode and battery assembly
[0053] Preparation of positive electrode: S and CNTs were thoroughly ground at a mass ratio of 4:1 and then dried to obtain S-CNTs powder for later use. The above S-CNTs powder, SuperP and PVDF were mixed at a mass ratio of 8:1:1, then coated on carbon-coated aluminum foil, dried and cut into circular positive electrode sheets (12 mm in diameter) for later use.
[0054] Battery assembly: The assembly was carried out in an argon glove box, using lithium metal sheets as the negative electrode, S-CNTs as the positive electrode, and P-Ov-In2O3NSs modified Celgard-2400 (PP) as the separator. The required electrolyte components were in the following proportions: the volume ratio of DOL to DME was 1:1, the concentration of LiTFSI was 1M, and the concentration of LiNO3 was 0.1M.
[0055] The assembled button cells were tested, data were collected, and analyzed using a Shanghai Chenhua electrochemical workstation (CHI760E). Cycling and other tests were performed on the assembled button cells using a Shenzhen Xinweier (CT-4008-5V 50mA-164) battery testing system.
[0056] To verify the effects of PP and P-Ov-In2O3 / / PP batteries on Li2S precipitation, Li2S nucleation tests were performed, and discharge profiles of PP and P-Ov-In2O3 / / PP batteries at a 2.05V potentiostat were collected, as shown below. Figure 4 As shown in figure a, Li2S is demonstrated. n Reconstructing the current curve for Li₂S, it can be seen that due to the effect of P-Ov-In₂O₃ on Li₂S... nThe catalytic conversion effect of P-Ov-In2O3 / / PP cells (7230s) showed that the Li2S nucleation time was shorter and the current change was faster than that of PP cells (15570s). To further verify the catalytic conversion effect of PP and P-Ov-In2O3 / / PP cells on Li2S... n The catalytic conversion effect was utilized, and a battery was assembled using two identical electrodes and the electrolyte Li₂S₆ within a voltage window of -1.0V to 1.0V. For example... Figure 4 As shown in b, the current density of the P-Ov-In2O3 / / PP symmetric cell is significantly higher than that of the PP symmetric cell, further illustrating that under the action of P-Ov-In2O3, Li2S n The kinetics of the transformation process are enhanced. Figure 4 c shows the charge-discharge curves of PP and P-Ov-In2O3 / / PP batteries at 0.1C. It can be seen that both curves exhibit a good discharge plateau, and the P-Ov-In2O3 / / PP battery has a higher initial discharge capacity at 0.1C. Figure 4 As can be seen from d, the polarization potential of the P-Ov-In2O3 / / PP battery (140mV) is significantly lower than that of the PP battery (180mV). This indicates that the charge-discharge plateau of the P-Ov-In2O3 / / PP battery is stable and can accelerate the redox reaction kinetics. It also demonstrates that P-Ov-In2O3 has a positive effect on Li2S... n It exhibits strong chemisorption capacity. Q1 and Q2 are the relative capacities of two typical plateaus, which can be used to represent the kinetics of the reduction process. Since the nucleation energy barrier of Li2S needs to be overcome at the second discharge plateau, the larger the Q2 / Q1 value, the faster the kinetic reaction. Figure 4 As can be seen from equation e, the Q2 / Q1 ratio of the P-Ov-In2O3 / / PP battery (1.87) is greater than that of the PP battery (1.41), indicating that the P-Ov-In2O3 / / PP battery exhibits faster kinetics. Typically, an inverted triangle and an upright triangle appear on the discharge and charge voltage curves, respectively. To further investigate the redox kinetics, [the following is a partial translation of the original text, which is incomplete and requires further context]. Figure 4 c. The beginning part of the second discharge plateau in the discharge voltage curve ( Figure 4 f) and the starting point and potential plateau portion of the charging voltage curve ( Figure 4 g) was enlarged. For example... Figure 4 The inverted triangle (corresponding to Li2S) is shown below. n (Reduced to Li₂S), the P-Ov-In₂O₃ / / PP cell exhibits a low overpotential, indicating that the P-Ov-In₂O₃ / / PP cell accelerates the conversion of Li₂S₄ to Li₂S. For Li₂S... n The formation of Li₂S, due to its insolubility and insulating properties, typically requires an overpotential to initiate the initial oxidation reaction. For example... Figure 4The g-shaped triangle represents the transformation of Li2S into Li2S. n The overpotential of the P-Ov-In2O3 / / PP battery (70mV) is lower than that of the PP battery (90mV), indicating that the P-Ov-In2O3 / / PP battery accelerates the conversion of Li2S to Li2S. n The transformation further demonstrates that the P-Ov-In2O3 / / PP battery improves the redox kinetics of sulfur. Figure 4 h represents the rate performance of PP and P-Ov-In2O3 / / PP batteries at current densities of 0.1C, 0.2C, 0.5C, 1.0C, 2.0C, and 5.0C. As the current density increases sequentially, the discharge specific capacities of the P-Ov-In2O3 / / PP batteries are 1271, 1179, 994, 883, 802, and 656 mAhg, respectively. -1 When the current density reaches 0.1C again, the discharge specific capacity of the P-Ov-In2O3 / / PP battery can still reach 1056 mAh g. -1 Therefore, compared with PP batteries, P-Ov-In2O3 / / PP batteries have better rate performance. Figure 4 i represents the charge-discharge curves of the P-Ov-In2O3 / / PP battery at different current densities. Even when the current density increases to 5.0C, a clear charge-discharge plateau is still visible. This is because the P-Ov-In2O3 / / PP battery improves the capture of Li2S. n The limited capacity of the discharge platform leads to a downward trend, while the charging platform shows a steady upward trend.
[0057] To compare PP and P-Ov-In2O3 / / PP batteries at 1.0 mg cm⁻¹ -2 Sulfur surface loading, coulombic efficiency at 1.0C, and cycle performance, in Figure 5 The long-cycle and coulombic efficiency curves of PP and P-Ov-In2O3 / / PP batteries were studied. Compared with PP batteries, P-Ov-In2O3 / / PP batteries showed a higher initial discharge specific capacity (867 mAh g). -1 After 500 cycles, the discharge specific capacity of the P-Ov-In2O3 / / PP battery remained at 564 mAh g. -1 The capacity decay rate per cycle is 0.069%, and the coulombic efficiency is close to 100%. These results indicate that the P-Ov-In2O3 / / PP battery can accelerate the Li2S... n Catalytic conversion to reduce Li2S n Accumulation in the electrolyte, for Li2S nThe shuttle effect was strongly suppressed, exhibiting good cycle stability. To investigate the effect of sulfur loading on P-Ov-In2O3 / / PP batteries, the sulfur surface loading was increased to 4.5 mg / cm³. -2 ,like Figure 5 As shown in b, under 0.2C conditions, the initial discharge specific capacity of the P-Ov-In2O3 / / PP battery is 804 mAh g. -1 After 100 cycles, its discharge specific capacity is 633 mAh g. -1 The coulomb efficiency is approximately 97%, with a capacity decay rate of 0.21% per revolution. Furthermore, at 4.5 mg cm⁻¹... -2 After 100 cycles at 0.2C with high areal capacity, it exhibited a capacity of 3.68 mAh / cm³. -2 The surface capacity. For example... Figure 5 As shown in Figure c, a P-Ov-In2O3 / / PP battery was used to light up the LED marked "2023", proving that the P-Ov-In2O3 / / PP battery has practical application prospects.
[0058] Therefore, this invention employs the aforementioned method for preparing P-Ov-In2O3 nanospheres and their application in lithium-sulfur battery separators. The introduction of oxygen defects disrupts the charge balance on the crystal surface, altering the electronic states and creating Li2S. n It provides highly efficient active sites, accelerating Li2S n The conversion of phosphorus was accelerated; phosphorus doping accelerated ion diffusion kinetics and improved the conductivity of the material; the P-Ov-In2O3 / / PP battery exhibited excellent cycling performance in electrochemical performance tests, maintaining a discharge specific capacity of 564 mAh g⁻¹ after 500 cycles at 1.0C. -1 Moreover, the capacity decay rate per revolution is only 0.069%.
[0059] Finally, it should be noted that the above embodiments are only used to illustrate the technical solutions of the present invention and not to limit them. Although the present invention has been described in detail with reference to preferred embodiments, those skilled in the art should understand that modifications or equivalent substitutions can still be made to the technical solutions of the present invention, and these modifications or equivalent substitutions cannot cause the modified technical solutions to deviate from the spirit and scope of the technical solutions of the present invention.
Claims
1. A method for preparing P-Ov-In2O3 nanospheres, characterized in that, The method comprises the following steps: S1, adding In(NO3)3·2H2O into a glass bottle containing ethylene glycol, and stirring magnetically until the solution is clear and transparent; S2, then placing the glass bottle containing the solution obtained in step S1 in the inner liner of a reaction kettle containing hypophosphorous acid, and hydrothermally reacting in a blast drying oven to obtain P-Ov-In2O3 NSs precipitate; S3, finally washing the P-Ov-In2O3 NSs precipitate with deionized water and anhydrous ethanol for 3 times, and drying in a blast drying oven at 50℃ for 24 h to obtain P-Ov-In2O3 NSs nanospheres, wherein the P-Ov-In2O3 NSs nanospheres are In2O3 nanospheres containing both phosphorus doping and oxygen defects.
2. The method for preparing P-Ov-In2O3 nanospheres according to claim 1, characterized in that, The ratio of ethylene glycol to hypophosphorous acid is 7:
6.
3. The method according to claim 1, wherein the P-Ov-In2O3 nanospheres are prepared by the following steps: (1) preparing a P-Ov-In2O3 precursor; (2) preparing a P-Ov-In2O3 nanosphere by using the P-Ov-In2O3 precursor. In step S1, the In(NO3)3·2H2O is added into the glass bottle containing ethylene glycol at a ratio of 40 mg In(NO3)3·2H2O per 7 mL ethylene glycol.
4. The method according to claim 1, wherein the P-Ov-In2O3 nanospheres are prepared by the following steps: (1) preparing a P-Ov-In2O3 precursor; (2) preparing a P-Ov-In2O3 nanosphere by using the P-Ov-In2O3 precursor. In step S2, the reaction temperature is 200℃ and the reaction time is 6 h.
5. Use of P-Ov-In2O3 nanospheres in a lithium-sulfur battery separator, characterized in that, The P-Ov-In2O3 nanospheres are prepared by the method of any one of claims 1-4.
6. The use of a P-Ov-In2O3 nanosphere according to claim 5 in a lithium-sulfur battery separator, characterized in that, The method comprises the following steps: (1) preparing P-Ov-In2O3 NSs modified separator; (2) preparing positive electrode sheet; (3) assembling the battery.
7. Use of P-Ov-In2O3 nanospheres according to claim 6 in a lithium-sulfur battery separator, characterized in that, In step (1), the preparation of P-Ov-In2O3 NSs modified separator comprises: placing P-Ov-In2O3 NSs nanospheres, acetylene black and polyvinylidene fluoride in a glass bottle at a mass ratio of 8:1:1, and stirring magnetically for 12 h to obtain a mixed slurry; coating the mixed slurry on the separator to obtain a P-Ov-In2O3 NSs modified separator; drying the obtained P-Ov-In2O3 NSs modified separator in a 50℃ blast drying oven for 1 h and then transferring it to a 50℃ vacuum drying oven for drying for 12 h, and then cutting it into a circular separator sheet with a diameter of 16 mm.
8. Use of P-Ov-In2O3 nanospheres according to claim 6 in a lithium-sulfur battery separator, characterized in that, In step (2), the preparation of the positive electrode sheet comprises: thoroughly grinding S and CNTs at a mass ratio of 4:1 and then drying to obtain S-CNTs powder; mixing the S-CNTs powder, acetylene black and polyvinylidene fluoride at a mass ratio of 8:1:1, and then coating on a carbon-coated aluminum foil and drying at 50℃, and then cutting into a S-CNTs circular positive electrode sheet with a diameter of 12 mm.
9. The use of P-Ov-In2O3 nanospheres according to claim 6 in lithium-sulfur battery separators, characterized by the fact that, In step (3), the assembly of the battery comprises: performing in an argon glove box, taking a metal lithium sheet as the negative electrode, a S-CNTs circular positive electrode sheet as the positive electrode, and a P-Ov-In2O3 NSs modified separator as the separator, and the corresponding ratios of the components of the required electrolyte are as follows: the volume ratio of DOL and DME is 1:1, the concentration of LiTFSI is 1 M, and the concentration of LiNO3 is 0.1 M.