Iron-magnesium-cerium co-doped titanium niobate negative electrode material, preparation method and application thereof

Abstract

The application discloses an iron-magnesium-cerium co-doped titanium niobate negative electrode material and a preparation method and application thereof. A niobium source, a titanium source and a doping element source are mixed, ball milled and calcined to obtain the titanium niobate negative electrode material. The preparation method is simple and easy for batch production, and the prepared titanium niobate product has high capacity under high rate.

Description

Technical Field

[0001] This application relates to an iron-magnesium-cerium co-doped titanium niobate anode material, its preparation method, and its application, belonging to the field of electrode materials. Background Technology

[0002] With the development and utilization of power equipment, there is a need to store and release electrical energy in different application scenarios. Improving energy density while developing fast-charging technology helps alleviate energy replenishment anxiety and better meets market demands. Traditional graphite anodes have low lithium intercalation potentials, making them prone to lithium dendrite formation during rapid charging and discharging, leading to decreased cycle stability and certain safety hazards. Therefore, there is an urgent need to develop anode materials with high energy density, high power density, and long cycle life.

[0003] Titanium niobate anode materials possess a higher operating potential (~1.6V), which can suppress lithium deposition and the formation of the solid electrolyte interphase (SEI), ensuring safety during long-term cycling. Furthermore, titanium niobate anode materials exhibit multiple redox couples, with a theoretical capacity of 387.6 mAh / g, similar to graphite. Their higher tap density ensures the battery's volumetric energy density, thus attracting widespread attention and research. Despite these advantages, the inherently low ionic and electronic conductivity of titanium niobate materials limits their further applications. Summary of the Invention

[0004] To address the aforementioned issues, this application provides a method for preparing and applying iron-magnesium-cerium co-doped titanium niobate anode materials. The method enables large-scale preparation of anode materials through a simple solid-state sintering process, and improves the electrochemical performance of the materials through multi-element synergistic doping, thereby promoting their commercial development.

[0005] According to one aspect of this application, a method for preparing an iron-magnesium-cerium co-doped titanium niobate anode material is provided, comprising the following steps:

[0006] The niobium source, titanium source, and dopant source are mixed, ball-milled, and calcined to obtain the titanium niobate anode material.

[0007] The niobium source is selected from at least one of niobium pentoxide, niobium pentachloride, niobium oxalate, and niobium ethoxide;

[0008] The titanium source is at least one of titanium dioxide, tetrabutyl titanate, titanium hydroxide, and titanium oxysulfate.

[0009] The dopant source is selected from at least one of oxides, hydroxides, sulfates, nitrates, and carbonates containing the dopant element.

[0010] The molar ratio of the niobium source, titanium source, and dopant source is 0.9–1.1:0.9–1.1:0.0005–0.05, based on the molar amounts of niobium, titanium, and dopant elements in the niobium source, titanium source, and dopant source.

[0011] The ball mill rotates at a speed of 100–1000 rpm;

[0012] The ball milling time is 2 to 24 hours.

[0013] The calcination temperature is 800–1300℃;

[0014] The calcination time is 10–30 hours;

[0015] The heating rate during calcination is 0.5–20 °C / min;

[0016] The calcination atmosphere is selected from at least one of pure oxygen, air, nitrogen, and argon.

[0017] According to another aspect of this application, a titanium niobate anode material prepared by the above-described preparation method is provided.

[0018] According to another aspect of this application, a negative electrode is provided, comprising the above-described titanium niobate negative electrode material.

[0019] The negative electrode is obtained through the following steps:

[0020] (1) Grind titanium niobate material, conductive agent, and binder into a uniform slurry using solvent I;

[0021] (2) Apply the slurry to the copper foil / carbon-coated copper foil with a scraper to a thickness of 50-1000 μm;

[0022] (3) After pre-baking the coated copper foil / carbon-coated copper foil for 1-5 hours, heat up and vacuum dry for 10-24 hours, then cut it into electrode sheets with a diameter of 10 mm or 12 mm.

[0023] Solvent I is selected from water or N-methylpyrrolidone;

[0024] The conductive agent is selected from acetylene black, Ketjen black, or carbon nanotubes.

[0025] The adhesive is selected from sodium carboxymethyl cellulose, ethyl cellulose, sodium alginate, polytetrafluoroethylene, polyvinylidene fluoride, and styrene-butadiene rubber.

[0026] According to another aspect of this application, an application of the above-described negative electrode in a battery is provided.

[0027] The beneficial effects that this application can produce include:

[0028] (1) This application improves the electronic conductivity and electrochemical performance of titanium niobate by adjusting the ratio and type of niobium source, titanium source and doping element source, thereby obtaining a titanium niobate anode material with good rate performance.

[0029] (2) The preparation method provided in this application provides a low-cost, simple-to-operate, and industrially-friendly method for synthesizing high-performance titanium niobate materials.

[0030] (3) The liquid lithium-ion button battery assembled with the iron-magnesium-cerium co-doped titanium niobate material described in this invention still has a high capacity under high current. Attached Figure Description

[0031] Figure 1 This is a scanning electron microscope image of iron-magnesium-cerium co-doped titanium niobate obtained in Example 1 of this application; the scale is 2 μm.

[0032] Figure 2 The XRD pattern of iron-magnesium-cerium co-doped titanium niobate obtained in Example 1 of this application;

[0033] Figure 3 The rate performance of the titanium niobate materials obtained in Examples 1 and 3 of this invention when used as negative electrodes in lithium-ion batteries is from 0.2C to 50C. Detailed Implementation

[0034] To make the objectives, technical solutions, and advantages of the embodiments of the present invention clearer, the technical solutions in the embodiments of the present invention will be clearly and completely described below. Where specific conditions are not specified in the embodiments, conventional conditions or conditions recommended by the manufacturer shall apply. Reagents or instruments whose manufacturers are not specified are all conventional products that can be purchased commercially.

[0035] The following analysis of sample morphology was performed using a scanning electron microscope (SEM, Quanta-200F); sample composition was performed using an X-ray diffractometer (XRD, SmartLab); and electrochemical performance was performed using a LAND CT3001A battery system (Wuhan Landian Electronics Co., Ltd.).

[0036] Example 1

[0037] Weigh out 10 mmol of niobium pentoxide, 10 mmol of titanium dioxide, and 0.1% of the molar amounts of iron tetroxide, magnesium oxide, and cerium oxide, respectively, as 10 mmol of TiNb2O7. After ball milling and mixing evenly, calcine at 1000℃ for 24 h in air atmosphere to obtain iron-magnesium-cerium co-doped titanium niobate product.

[0038] Titanium niobate, conductive agent acetylene black, and binder carboxymethyl cellulose were ground into a uniform slurry using water as a solvent. The slurry was then coated onto copper foil / carbon-coated copper foil to a thickness of 200 μm using a doctor blade. After pre-baking the coated copper foil / carbon-coated copper foil, it was heated to 80°C and vacuum-sealed for 12 hours before being cut into electrode sheets with a diameter of 12 mm. This negative electrode sheet was then assembled with a lithium-ion cell to form a lithium-ion battery.

[0039] Example 2

[0040] Other operations are the same as in Example 1, except that the molar amounts of iron tetroxide, magnesium oxide, and cerium oxide are 1% of 10 mmol TiNb2O7. After being ball-milled and mixed evenly, the mixture is calcined at 1000°C in air for 24 hours to obtain iron-magnesium-cerium co-doped titanium niobate product.

[0041] Titanium niobate, conductive agent acetylene black, and binder carboxymethyl cellulose were ground into a uniform slurry using water as a solvent. The slurry was then coated onto copper foil / carbon-coated copper foil to a thickness of 200 μm using a doctor blade. After pre-baking the coated copper foil / carbon-coated copper foil, it was heated to 80°C and vacuum-dried for 12 hours before being cut into electrode sheets with a diameter of 12 mm. This negative electrode sheet was then assembled with a lithium-ion cell to form a lithium-ion battery.

[0042] Example 3

[0043] Other operations are the same as in Example 1, except that the molar amounts of iron tetroxide, magnesium oxide, and cerium oxide are 2% of 10 mmol TiNb2O7. After being ball-milled and mixed evenly, the mixture is calcined at 1000°C in air for 24 hours to obtain iron-magnesium-cerium co-doped titanium niobate product.

[0044] The prepared titanium niobate material, conductive agent acetylene black, and binder carboxymethyl cellulose were ground into a uniform slurry using water as a solvent. The slurry was then coated onto copper foil / carbon-coated copper foil with a thickness of 200 micrometers using a doctor blade. After pre-baking the coated copper foil / carbon-coated copper foil, it was heated to 80°C and vacuum-dried for 12 hours before being cut into electrode sheets with a diameter of 12 mm. This negative electrode sheet was then assembled with a lithium sheet to form a lithium-ion battery.

[0045] Example 4

[0046] The other operations are the same as in Example 1, except that the calcination is carried out in an air atmosphere at a temperature of 1200°C for 24 hours.

[0047] The prepared titanium niobate material, conductive agent acetylene black, and binder carboxymethyl cellulose were ground into a uniform slurry using water as a solvent. The slurry was coated onto copper foil / carbon-coated copper foil with a thickness of 200 μm using a doctor blade. After pre-baking the coated copper foil / carbon-coated copper foil, it was heated to 80°C and vacuum-dried for 12 hours before being cut into electrode sheets with a diameter of 12 mm. This negative electrode sheet was then assembled with a lithium sheet to form a lithium-ion battery.

[0048] Example 5

[0049] The other operations are the same as in Example 1. The prepared titanium niobate material, conductive agent acetylene black, and binder polyvinylidene fluoride are ground into a uniform slurry using N-methylpyrrolidone solvent. The slurry is coated onto copper foil / carbon-coated copper foil with a thickness of 200 μm using a doctor blade. After pre-baking the coated copper foil / carbon-coated copper foil, it is heated to 80°C and vacuum-dried for 12 hours before being cut into electrode sheets with a diameter of 12 mm. This negative electrode sheet is then assembled with a lithium sheet to form a lithium-ion battery.

[0050] The above description is merely a few embodiments of this application and is not intended to limit this application in any way. Although this application discloses preferred embodiments as described above, it is not intended to limit this application. Any changes or modifications made by those skilled in the art without departing from the scope of the technical solution of this application using the disclosed technical content are equivalent to equivalent implementation cases and fall within the scope of the technical solution.

Claims

1. A method for preparing an iron-magnesium-cerium co-doped titanium niobate anode material, characterized in that, Includes the following steps: The niobium source, titanium source, and dopant source are mixed, ball-milled, and calcined to obtain the titanium niobate anode material.

2. The preparation method according to claim 1, characterized in that, The niobium source is selected from at least one of niobium pentoxide, niobium pentachloride, niobium oxalate, and niobium ethoxide; The titanium source is at least one of titanium dioxide, tetrabutyl titanate, titanium hydroxide, and titanium oxysulfate. The dopant source is selected from at least one of oxides, hydroxides, sulfates, nitrates, and carbonates containing the dopant element.

3. The preparation method according to claim 1, characterized in that, The molar ratio of the niobium source, titanium source, and dopant source is 0.9–1.1:0.9–1.1:0.0005–0.05, based on the molar amounts of niobium, titanium, and dopant elements in the niobium source, titanium source, and dopant source.

4. The preparation method according to claim 1, characterized in that, The ball mill rotates at a speed of 100–1000 rpm; The ball milling time is 2 to 24 hours.

5. The preparation method according to claim 1, characterized in that, The calcination temperature is 800–1300℃; The calcination time is 10–30 hours; The heating rate during calcination is 0.5–20 °C / min; The calcination atmosphere is selected from at least one of pure oxygen, air, nitrogen, and argon.

6. A titanium niobate anode material prepared by the preparation method according to any one of claims 1 to 5.

7. A negative electrode, characterized in that, The anode material containing titanium niobate as described in claim 6.

8. The application of the negative electrode as described in claim 7 in a battery.

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