A method for preparing self-doped titanium niobium oxide negative electrode material using waste titanium dioxide carrier, negative electrode material and lithium ion battery

Abstract

The present invention discloses a method for preparing a self-doped titanium niobium oxide negative electrode material from waste titanium dioxide carriers, the negative electrode material and a lithium ion battery. The method for preparing a self-doped TiNb2O7 negative electrode material for lithium batteries from waste titanium dioxide carriers according to the present invention comprises the following steps: S1. Taking oxides as the basis, converting the waste titanium dioxide carrier into TiO2 powder with a Ti content ≥ 95% and an Al content of 0.1 - 4.0%; S2. Mixing the TiO2 powder with Nb2O5 powder and then calcining, collecting the generated Al self-doped TiNb2O7 to obtain the self-doped TiNb2O7 negative electrode material. The method of the present invention can directly recycle TiO2 and impurities represented by Al2O3 in the waste titanium dioxide carrier, and directly prepare a self-doped TiNb2O7 (titanium niobium oxide) negative electrode material with excellent performance through a short process, realizing the high-value utilization of waste catalysts.

Description

Technical Field

[0001] The invention belongs to the field of recycling secondary resources of waste titanium dioxide carriers and high-value utilization, and relates to a method for directly preparing lithium-ion battery materials from waste materials, and in particular to a method for preparing titanium-based self-doped lithium battery negative electrode materials from waste carriers containing titanium dioxide. Background Art

[0002] The advantages of titanium dioxide as a catalyst carrier are its high chemical stability, large specific surface area, low cost, simple process, etc. At the same time, it also has good performance, and can use sunlight or purple external rays to stimulate its surface charge to promote the reaction. At present, catalysts with secondary titanium dioxide as carriers have been widely used in many fields, such as environmental pollution control, energy dump, organic materials and other fields. With the continuous increase in the use of titanium dioxide carriers, the number of titanium dioxide carriers scrapped each year is also increasing. If these scrapped waste catalyst carriers cannot be effectively recycled, it will not only pollute the environment, but also cause waste of resources. Therefore, properly handling waste titanium dioxide carriers has strong economic benefits and environmental significance.

[0003] Lithium-ion batteries have the characteristics of high energy density, long life, and fast charge and discharge. Currently, commercial lithium-ion batteries are not very capable in special battery application areas, such as deep sea, polar regions, and aviation. This is mainly because most of them use layered graphite-based carbon materials as negative electrodes, which have a low working potential (about 0.1V vs Li + / Li), which is prone to produce "lithium dendrites" during the charge and discharge process, causing short circuits and restricting its further development. 2 O 7 It not only has the advantages of long cycle life and high safety, but also has a high theoretical specific capacity (387 mAh / g), shows excellent structural stability during lithiation / delithiation, and has a relatively high working potential (relative to Li + / Li is 1.6V), which can effectively prevent the formation of "lithium dendrites" and greatly improve the safety of the battery system. At present, with the rapid development of the new energy industry and the saturation of the petroleum industry, recycling and preparing high-value materials from waste catalysts has become a more promising catalyst recycling route.

[0004] CN 114058853 A discloses a method for separating and recovering titanium, vanadium and tungsten from waste SCR catalysts, comprising the following contents: dusting and crushing the waste SCR catalysts, acidolyzing the waste catalyst powder with concentrated sulfuric acid, leaching the acidolysis product, allowing titanium, tungsten and vanadium in the waste catalyst to enter the leaching solution together, then using a weak alkaline extractant to extract titanium and tungsten, and using sulfuric acid and hydrogen peroxide to strip titanium in the organic phase. However, the prepared product has a low added value, so the preparation of new energy materials with higher added value has become a research frontier in the field. Summary of the invention

[0005] Based on the above content, in view of the problems existing in the existing process, such as long recycling process, large amount of waste acid and waste alkali used in the recycling process, and failure to make high-value use of the recycled products, the present invention provides a method for preparing self-doped titanium niobium oxide negative electrode material using waste titanium dioxide carrier, negative electrode material and lithium ion battery, which can directly recycle TiO in the waste titanium dioxide carrier. 2 And Al 2 O 3 The short process directly prepares self-doped TiNb with excellent performance. 2 O 7 (Titanium niobium oxide) negative electrode material realizes the high-value utilization of waste catalysts, improves environmental conditions and saves production costs.

[0006] The present invention provides a method for preparing self-doped TiNb for lithium batteries using waste titanium dioxide carrier 2 O 7 A method for producing a negative electrode material, comprising the steps of:

[0007] S1, respectively, the waste titanium dioxide carrier is converted into TiO with a Ti content of ≥95% and an Al content of 0.1% to 4.0%. 2 powder;

[0008] S2, the TiO 2 Powder and Nb 2 O 5 The powders were mixed and calcined, and the generated Al self-doped TiNb 2 O 7 , to obtain the self-doped TiNb 2 O 7 Negative electrode material.

[0009] In the present invention, the waste titanium dioxide carrier is a waste catalyst using titanium dioxide as a catalyst carrier, such as a waste SCR catalyst, a vanadium / titanium dioxide catalyst (V-TiO 2 ) and other waste catalysts. In a specific embodiment of the present invention, the waste SCR catalyst is taken as a waste titanium dioxide carrier as an example to describe the preparation method of the present invention in detail.

[0010] The above-mentioned method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier 2 O 7 In the method for negative electrode materials, in step S1, the waste TiO 2 The carrier is the TiO 2 The content of main impurity elements in the powder is qualified TiO 2Powder, wherein if the Ti content and Al content do not meet the standards, secondary impurity removal is required; in terms of oxide, the TiO 2 The Al content in the powder is preferably 0.1 to 3.0%, more preferably 0.1 to 2.0%;

[0011] Calculated as oxide, the TiO 2 The impurity V content in the powder is controlled at 0.01% to 0.3%, preferably 0.01% to 0.1%;

[0012] Calculated as oxide, the TiO 2 The content of impurity W in the powder is controlled at 0.1% to 1.0%, preferably 0.1% to 0.5%.

[0013] In the present invention, the content of Ti is expressed as TiO 2 The Al content is expressed as Al 2 O 3 V content is V 2 O 5 W content is calculated as WO 3 In a specific embodiment of the present invention, the TiO 2 The powder is digested with acid and then ICP is tested to obtain the content of each element. The digestion acid can be HF or aqua regia.

[0014] The above-mentioned method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier 2 O 7 In the method for producing negative electrode materials, preferably, the mass percentage of titanium dioxide in the waste titanium dioxide carrier is 70% to 95%;

[0015] The mass percentage of aluminum oxide in the waste titanium dioxide carrier is 4% to 10%;

[0016] The mass percentage of tungsten trioxide in the waste titanium dioxide carrier is 2% to 3%;

[0017] The mass percentage of vanadium pentoxide in the waste titanium dioxide carrier is 1% to 3%.

[0018] In a specific embodiment of the present invention, based on the total weight of the waste titanium dioxide carrier, the waste titanium dioxide carrier contains 76.50% titanium dioxide, 5.31wt% aluminum oxide, 2.94wt% tungsten trioxide, 0.93wt% vanadium pentoxide, 8.39wt% silicon dioxide and 0.30wt% molybdenum trioxide.

[0019] The above-mentioned method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier 2 O 7 In the method for producing negative electrode materials, preferably, the conversion step in step S1 comprises:

[0020] S10, physically crushing, washing and ball-milling the waste titanium dioxide carrier to obtain waste titanium dioxide carrier powder;

[0021] S11, mixing the waste titanium dioxide carrier powder and the sodium-containing roasting material and roasting them to convert the titanium dioxide into sodium titanium salt to obtain clinker;

[0022] S12, using water as a leaching agent, subjecting the clinker to a first leaching, collecting the first leached residue, and drying it;

[0023] S13, using acid as a leaching agent, leaching the first leaching residue for a second time, and collecting a second leaching liquid;

[0024] S14, adding an alkaline reagent to the second leaching solution, collecting the precipitate, drying and calcining it in sequence, to obtain the TiO 2 powder.

[0025] The inventive concept of step S1 in the present invention is as follows:

[0026] TiO was separated by “sodium roasting + water leaching + acid leaching precipitation + roasting” 2 The metal oxides in the spent catalyst are converted into the corresponding sodium salts (such as Na 2 TiO 3 、Na 2 WO 4 、NaVO 3 The water-soluble components of sodium salts are removed by water immersion. For the insoluble titanium sodium salts (such as Na 2 TiO 3 、Na 8 Ti 5 O 14 It can be dissolved in the solution by acid leaching, and then an appropriate amount of alkali is added to precipitate Ti by adjusting the pH of the solution, and finally a relatively pure TiO is obtained by high-temperature roasting. 2 .

[0027] The inventors of the present invention have found in the course of their research that by using the above conversion method and controlling specific heat treatment conditions and leaching reagents, a high content of TiO 2 Powder, effectively realize the efficient leaching of impurity ions and directly prepare high-value materials.

[0028] In step S10, the washing is water washing followed by drying. In a specific embodiment of the present invention, the surface fly ash impurities are removed by ultrasonic washing with deionized water and then placed in a vacuum drying oven for drying at 60°C;

[0029] Preferably, the ball mill passes through a 325 mesh sieve; the inventors have found that the specific implementation of this preferred situation can effectively reduce the particle size of the catalyst, which is beneficial to the subsequent heat treatment process;

[0030] The sodium-refined roasting material is sodium carbonate or sodium hydroxide; in a specific embodiment of the present invention, the waste titanium dioxide carrier powder and the sodium-refined roasting material are fully mixed in an agate mortar;

[0031] The mass ratio of the waste titanium dioxide carrier powder to the sodium-treated roasted material may be 1:(2-3), specifically 1:2, 1:2.5 or 1:3;

[0032] The calcination in step S11 is carried out in air atmosphere, the calcination temperature can be 650°C to 850°C, such as 700°C, 650°C or 750°C, and the holding time is 6 hours to achieve full reaction of titanium dioxide. In a specific embodiment of the present invention, the heating rate is 5°C / min.

[0033] In step S11, taking the roasting material as sodium carbonate as an example, the reaction equation that may occur during the sodium roasting process is as follows:

[0034] TiO 2 +Na 2 CO 3 →Na 2 TiO 3 +CO 2 ↑

[0035] Al 2 O 3 +Na 2 CO 3 →2NaAlO 2 +CO 2 ↑

[0036] WO 3 +Na 2 CO 3 →Na 2 WO 4 +CO 2 ↑

[0037] V 2 O 5 +Na 2 CO 3 →2NaVO 3 +CO 2 ↑

[0038] SiO 2 +Na 2 CO 3 →Na 2 SiO 3 +CO2 ↑

[0039] MoO 3 +Na 2 CO 3 →Na 2 MoO 4 +CO 2 ↑

[0040] Through the above reaction, each element in the spent titanium dioxide carrier is converted into corresponding salt.

[0041] Step S11 also includes passing the clinker through a 200-mesh sieve for standby use;

[0042] In step S12, preferably, the temperature of the first leaching may be 60°C to 90°C, such as 60°C to 80°C, 60°C, 70°C or 80°C;

[0043] The first leaching time is 1h to 10h, such as 6h;

[0044] The material-liquid ratio of the first leaching is 1g:30mL;

[0045] Under the above conditions, the main component of the first leaching solution is NaVO 3 、Na 2 WO 4 、NaAlO 2 The first leaching residue is mainly composed of Na 2 TiO 3 、Na 8 Ti 5 O 14 、Na 2 Ti 3 O 7 etc. containing titanium sodium salts, and a small amount of unreacted Al 2 O 3 And other impurity elements.

[0046] The first leached residue is dried by vacuum drying at a temperature of 60° C. to 90° C. (such as 60° C.) for 12 hours.

[0047] In step S13, preferably, the acid is H 2 SO 4 , one or more of HCl;

[0048] The acid is present in the form of an aqueous solution thereof, and the concentration may be 3 to 5 mol / L, such as 5 mol / L;

[0049] The temperature of the second leaching may be 80-90°C, such as 80°C;

[0050] The second leaching time may be 5 to 24 hours, such as 6 hours;

[0051] The material-liquid ratio of the second leaching is 1g:30mL, such as 1g:30mL;

[0052] Under the above conditions, the main component of the second leachate is TiOSO 4 .

[0053] In step S13, the leaching acid is H 2 SO 4 For example, the reaction equation that may occur during the leaching process is as follows:

[0054] Na 2 TiO 3 +2H + →H 2 TiO 3 +2Na +

[0055]

[0056] Through the above reaction, the sodium titanium salt which is hardly soluble in water in the waste titanium dioxide carrier is dissolved in the acid.

[0057] In the present invention, the system after leaching can be subjected to solid-liquid separation to collect the leachate or leaching residue. The solid-liquid separation method includes but is not limited to separation methods such as centrifugation.

[0058] In step S13, preferably, the alkaline reagent can be ammonia water, Na 2 CO 3 , NaOH, urea or more;

[0059] The alkaline agent is added in the form of an aqueous solution with a concentration of 1 to 100 g / L, such as 100 g / L;

[0060] The aqueous solution of the alkaline reagent is dripped at a rate of 0.5 to 1 ml / min, such as 0.5 ml / min;

[0061] The amount of the alkaline agent added can be controlled so that the pH value of the system can be 2.5 to 5, such as 4 to 5, 4 or 5;

[0062] The precipitate is H 2 TiO 3 By adding alkaline solution to adjust the pH of the solution, the TiO 2+ Complete precipitation. Taking the leaching acid as H 2 SO 4 For example, the reaction equation that may occur when adding an alkaline solution is as follows:

[0063]

[0064] The drying in step S14 is vacuum drying, the drying temperature is 60-80° C., such as 60° C., and the time can be 12-24 hours, such as 12 hours;

[0065] The calcination in step S14 is carried out in an air atmosphere, at a calcination temperature of 600° C., and a holding time of 3 to 5 hours (e.g., 3 hours). In a specific embodiment of the present invention, the heating rate is set at 5° C. / min. The reaction equation is as follows:

[0066] H 2 TiO 3 →TiO 2 +H 2 O↑

[0067] The above-mentioned method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier 2 O 7 In the method for preparing the negative electrode material, a high temperature solid phase method is used in step S2;

[0068] Optionally, the Nb 2 O 5 The powder is commercial Nb 2 O 5 Material;

[0069] Preferably, the TiO 2 Powder with the Nb 2 O 5 The molar ratio of the powder is 1.05:1;

[0070] The TiO 2 Powder with the Nb 2 O 5 After mixing the powders, the mixture was passed through a 325-mesh sieve to obtain a powder precursor with a particle size of ≤45 μm;

[0071] The calcination in step S2 is carried out in air atmosphere, the calcination temperature can be 1100°C to 1300°C, such as 1100°C, 1150°C, 1300°C, and the holding time can be 8 to 12 hours, such as 10 hours. In a specific embodiment of the present invention, the heating rate is 5°C / min.

[0072] In a specific embodiment of the present invention, the calcination is carried out in a muffle furnace.

[0073] The present invention further provides any one of the above-mentioned methods for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier. 2 O 7 Self-doped TiNb prepared by the method of negative electrode material 2 O 7 Negative electrode material.

[0074] The present invention also provides a lithium ion battery, comprising a positive electrode sheet, a negative electrode sheet, a separator and an electrolyte, wherein the negative electrode sheet comprises a current collector and the self-doped TiNb loaded on the current collector. 2 O 7 Negative electrode material.

[0075] For example, the current collector is copper foil; the positive electrode is a lithium metal sheet; the separator is a PE separator; the electrolyte contains 1 mol / L LiPF 6 EC:DMC=1:1 (vol).

[0076] The present invention has the following beneficial effects:

[0077] (1) The present invention prepares Al self-doped lithium ion battery negative electrode material TiNb by using waste titanium dioxide carrier containing aluminum oxide 2 O 7 , to achieve waste TiO 2 Preparation of new ultra-fast charging negative electrode material-titanium niobium oxide TiNb 2 O 7 , can be used as negative electrode materials for lithium-ion batteries, increasing the economic added value. 2 O 7 For negative electrode materials, Al self-doped lithium-ion battery negative electrode material TiNb 2 O 7 Although the initial specific capacity is slightly lower than that of undoped commercial materials, the material has excellent cycle stability during subsequent charge and discharge processes.

[0078] (2) The present invention converts the waste titanium dioxide carrier into a Ti-containing (TiO 2 The Al content (in terms of Al 2 O 3 0.1-4.0% TiO 2 Powder, commercial Nb 2 O 5 Materials and treated TiO 2 The powder was ground and calcined to obtain Al self-doped TiNb 2 O 7 product.

[0079] (3) By rationally controlling the sodium calcination pretreatment temperature and combining the water immersion and acid pickling precipitation conditions, TiO with the required Ti and Al contents can be obtained. 2 powder. BRIEF DESCRIPTION OF THE DRAWINGS

[0080] Figure 1The present invention uses waste titanium dioxide as a carrier to prepare self-doped TiNb for lithium batteries 2 O 7 Flowchart of negative electrode materials.

[0081] Figure 2 The self-doped TiNb prepared in Example 1 2 O 7 XRD spectra of negative electrode material samples.

[0082] Figure 3 The self-doped TiNb prepared in Example 1 2 O 7 SEM-EDS photos of negative electrode material samples.

[0083] Figure 4 The self-doped TiNb prepared in Example 1 2 O 7 Negative electrode material (left) and TiNb prepared from commercial materials 2 O 7 Comparison of the charge and discharge performance of the negative electrode material (right) in the first five cycles.

[0084] Figure 5 The self-doped TiNb prepared in Example 1 2 O 7 CV performance test chart of negative electrode material at 1.0-3.0V and scan rate of 0.1mV / s.

[0085] Figure 6 The self-doped TiNb prepared in Example 1 2 O 7 Impedance performance diagram of the battery with negative electrode material after activation 3 times at a rate of 1C and cycled 10 times, 20 times, 50 times, and 100 times respectively. DETAILED DESCRIPTION

[0086] The present invention is further described in detail below in conjunction with specific embodiments, and the examples provided are only for illustrating the present invention, rather than for limiting the scope of the present invention. The examples provided below can be used as a guide for further improvements by those of ordinary skill in the art, and do not constitute a limitation of the present invention in any way.

[0087] Unless otherwise specified, the experimental methods used in the following examples are all conventional methods; the materials, reagents, etc. used, unless otherwise specified, can be obtained from commercial channels.

[0088] In the following examples, based on the total weight of the waste titanium dioxide carrier, the waste titanium dioxide carrier contains 76.50 wt% titanium dioxide, 5.31 wt% aluminum oxide, 2.94 wt% tungsten trioxide, 0.93 wt% vanadium pentoxide, 8.39 wt% silicon dioxide and 0.30 wt% molybdenum trioxide.

[0089] The commercial TiO 2 The purity is 99%.

[0090] The calcinations in the following examples were all carried out in an air atmosphere (in a muffle furnace) unless otherwise specified.

[0091] Example 1

[0092] This embodiment provides a method for preparing a lithium-ion battery self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 methods, such as Figure 1 As shown, the method comprises the following steps:

[0093] (1) After the spent titanium dioxide carrier is physically crushed, it is ultrasonically washed with deionized water to remove fly ash impurities on the surface, and then placed in a vacuum drying oven at 60° C. The dried spent titanium dioxide carrier is ball-milled and passed through a 325-mesh sieve.

[0094] (2) Place 5.00 g of spent titanium dioxide carrier in a corundum crucible and add 10.00 g of Na 2 CO 3 After mixing and grinding evenly, the mixture was placed in a muffle furnace for roasting (roasting temperature 700°C, holding time 6h, heating rate set at 5°C / min), and cooled in the furnace. After the sample was cooled, the sample was taken out to obtain 13.64g of heat-treated clinker. The heat-treated clinker contained Na 2 TiO 3 、Na 8 Ti 5 O 14 、Na 2 Ti 3 O 7 、NaAlO 2 、NaVO 3 、Na 2 WO 4 Etc. And pass the material through a 200-mesh sieve for later use.

[0095] (3) 3 g of the above heat-treated clinker was placed in a 250 ml beaker, 90 ml of deionized water was added, and the mixture was leached in a 60° C. water bath for 6 h. The mixture was then centrifuged at a low speed to obtain a first leaching solution and a first leaching residue. The first leaching residue was placed in a 60° C. drying oven for 12 h to obtain a dry sample.

[0096] (4) Weigh 1 g of the dried sample and place it in a 100 ml beaker. Add 30 ml of 5 mol / L H 2 SO 4 , leached in a water bath at 80°C for 6 hours, and then centrifuged at a low speed to obtain a second leaching solution and a second leaching residue.

[0097] (5) Weigh 10 ml of the second leachate and place it in a 100 ml beaker and stir. Use a peristaltic pump to slowly drip a 50 g / L ammonia solution into the mixed solution at a rate of 0.5 ml / min until the pH value reaches 5.

[0098] (6) The mixture was vacuum filtered and placed in a vacuum drying oven for drying at 80°C for 24 h, and then calcined in a muffle furnace (calcination temperature 600°C, holding time 3 h, heating rate setting 5°C / min) to obtain TiO 2 Powder. After testing, the content of each element is as follows: Ti content (as TiO 2 The Al content (in terms of Al 2 O 3 ) is 2.91%, V content (content in V 2 O 5 0.08% and W content (in WO 3 The amount of Nb was 0.98%, and then commercial Nb 2 O 5 Powder, according to the molar ratio of TiO 2 :Nb 2 O 5 =1.05:1, mixed and ground, and passed through a 325-mesh sieve to obtain a mixed powder with a particle size of ≤45 μm.

[0099] (7) The mixed powder was placed in a muffle furnace for calcination (calcination temperature 1000°C, holding time 10h, heating rate 5°C / min), and cooled in the furnace. 2 O 7 .

[0100] The Al self-doped TiNb obtained in this embodiment 2 O 7 XRD of negative electrode materials Figure 2 As shown in Figure 2, the SEM-EDS results are as follows: Figure 3 As shown. 2 O 7 (calculated as Al-TNO, the same below) and TiNb prepared from commercial materials 2 O 7The charge and discharge performance of the first five cycles (measured in TNO, the same below) is compared. The specific steps are as follows: Al-TNO / TNO, acetylene black and polyvinylidene fluoride (PVDF) are mixed in a weight ratio of 8:1:1 to prepare Al-TNO / TNO electrode sheets; wherein the mass fraction of the binder is 7%, and the solvent is N-methylpyrrolidone (NMP). The prepared slurry is stirred in a stirrer for 12 hours; the evenly stirred slurry is coated on the copper foil with a coating thickness of 100um; then it is dried continuously at 90°C in a vacuum drying oven for 12 hours to remove excess NMP and water; after drying, it is cut into circular electrode sheets with a diameter of 12mm, weighed and placed in a glove box for use. The prepared electrode sheet is used as the positive electrode, the lithium metal sheet is used as the counter electrode (diameter 16mm), the diaphragm is PE (diameter 19mm), and the electrolyte contains 1mol / L LiPF 6 EC:DMC=1:1(vol). CR2032 button half-cells were assembled in a glove box. Battery performance was tested using a CT2001A blue battery test system. The assembled battery was charged and discharged three times at a 0.1C rate to activate the battery. The battery test range was 0.8-3.0V. The CV scan rate was 0.1~1mv s -1 All tests were conducted at room temperature. Figure 4 As shown, compared with commercial TNO materials ( Figure 4 For example, after self-doping, the Al-TNO material ( Figure 4 Left) The charge and discharge capacity decay in the first five cycles is low, indicating that the battery is more stable after Al doping.

[0101] Figure 5 This is the CV performance test diagram of Al-TNO material at 1.0-3.0V and a scan rate of 0.1mV / s. It can be seen that the three pairs of redox couples are fully reflected in the CV curve of Al-TNO material.

[0102] The impedance performance of Al-TNO was tested in the frequency range of 0.01-10 5 The amplitude of the Hz sinusoidal alternating current signal is 5 mV. The impedance test of the battery was carried out using Shanghai Chenhua CHI760E electrochemical workstation. Figure 6 The impedance performance diagram of the battery after activation 3 times at 1C rate, and cycled 10 times, 20 times, 50 times, and 100 times. It can be seen that the initial electrochemical polarization resistance R ct It is about 3Ω, and increases after cycling and activation. Especially after 100 cycles, the impedance increases from the initial 3Ω to about 22Ω. This shows that although Al doping will slightly reduce the initial performance of the battery, the battery capacity decays slowly. This may be because the addition of Al stabilizes the lattice gap.

[0103] The performance of the battery material prepared in this example is shown in Table 1.

[0104] Example 2

[0105] This example uses a method similar to that of Example 1 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The method is different in that in step (7), the heating temperature is 1150° C. and the time is 8 h.

[0106] The performance of the battery material prepared in this example is shown in Table 1.

[0107] Example 3

[0108] In this embodiment (1)-(4), a titanium-based self-doped lithium battery negative electrode material TiNb was prepared from waste titanium dioxide carrier by a method similar to that of embodiment 1. 2 O 7 The method is different in that in step (5), 10 ml of the second leachate is weighed and placed in a 100 ml beaker and stirred, and the urea aqueous solution (100 g / L) is slowly dripped into the mixed solution at a rate of 0.5 ml / min using a peristaltic pump until the pH value reaches 4.

[0109] (6) The precipitate was filtered and dried in a vacuum oven at 60°C for 12 h to obtain crystals. The crystals were ground in a mortar and then calcined in a muffle furnace (calcination temperature 600°C, holding time 3 h, heating rate set at 5°C / min) to obtain TiO 2 The powder was tested and the content of each element was as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 2.89%, V content (content in V 2 O 5 0.15% and W content (in WO 3 The total weight of the product is 0.21%.

[0110] (7) TiO 2 Compared with commercial Nb 2 O 5 The mixture was mixed and ground according to a molar ratio of 1.05:1 and passed through a 325-mesh sieve to obtain a powder precursor with a particle size of ≤45 μm.

[0111] (8) The mixed powder was placed in a muffle furnace for calcination (calcination temperature 1100°C, holding time 10h, heating rate 5°C / min), and cooled in the furnace. 2 O 7 .

[0112] The performance of the battery material prepared in this example is shown in Table 1.

[0113] Example 4

[0114] This example uses a method similar to that of Example 3 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The difference is that in step (2), NaOH is used as the feed material. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 3.77%, V content (content in V 2 O 5 The W content (in WO 3 The total amount is 0.19%.

[0115] The performance of the battery material prepared in this example is shown in Table 1.

[0116] Example 5

[0117] This example uses a method similar to that of Example 3 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The difference is that in step (5), NaOH is used as the feed material. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 2.43%, V content (content in V 2 O 5 0.09% and W content (in WO 3 The total weight of the product is 0.17%.

[0118] The performance of the battery material prepared in this example is shown in Table 1.

[0119] Example 6

[0120] This example uses a method similar to that of Example 3 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The method is different in that in step (8), the calcination temperature is 1300°C.

[0121] The performance of the battery material prepared in this example is shown in Table 1.

[0122] Example 7

[0123] This example uses a method similar to that of Example 1 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The difference is that in step (2), the amount of sodium carbonate used is 12.5 g, that is, the ratio of the amount of additive to the material is 2.5. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 3.89%, V content (content in V 2 O 5 The W content (in WO 3 The total weight of the product is 0.21%.

[0124] The performance of the battery material prepared in this example is shown in Table 1.

[0125] Example 8

[0126] This example uses a method similar to that of Example 1 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The difference is that in step (2), the amount of sodium carbonate used is 15g, that is, the ratio of the amount of additive to the material is 3. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 3.11%, V content (content in V 2 O 5 0.08% and W content (in WO 3 The performance of the battery material prepared in this example is shown in Table 1.

[0127] Example 9

[0128] This example uses a method similar to that of Example 1 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The method is different in that the calcination temperature in step (2) is 650°C. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 3.76%, V content (content in V 2 O 50.19% and W content (in WO 3 The total amount is 0.22%.

[0129] The performance of the battery material prepared in this example is shown in Table 1.

[0130] Example 10

[0131] This example uses a method similar to that of Example 1 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The method is different in that the calcination temperature in step (2) is 750°C. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 2.93%, V content (content in V 2 O 5 0.06% and W content (in WO 3 The total weight of the product is 0.17%.

[0132] The performance of the battery material prepared in this example is shown in Table 1.

[0133] Embodiment 11

[0134] This example uses a method similar to that of Example 2 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The method is different in that the leaching temperature in step (3) is 70°C. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O 3 ) is 3.15%, V content (content in V 2 O 5 0.03% and W content (in WO 3 The total weight of the product is 0.16%.

[0135] Example 12

[0136] This example uses a method similar to that of Example 2 to prepare titanium-based self-doped lithium battery negative electrode material TiNb from waste titanium dioxide carrier 2 O 7 The difference is that in step (3), the leaching temperature is 80°C. In step (6), after testing, the content of each element is as follows: Ti content (in terms of TiO 2 The Al content (in terms of Al 2 O3 ) is 2.78%, V content (content in V 2 O 5 0.05% and W content (in WO 3 The total weight of the product is 0.21%.

[0137] Comparative Example 1

[0138] This example uses a method similar to that of Example 1 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that steps (1)-(5) are eliminated and commercial TiO 2 With Nb 2 O 5 mix.

[0139] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0140] Comparative Example 2

[0141] This example uses a method similar to that of Example 2 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0142] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0143] Comparative Example 3

[0144] This example uses a method similar to that of Example 3 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0145] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0146] Comparative Example 4

[0147] This example uses a method similar to that of Example 4 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0148] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0149] Comparative Example 5

[0150] This example uses a method similar to that of Example 5 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0151] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0152] Comparative Example 6

[0153] This example uses a method similar to that of Example 6 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0154] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0155] Comparative Example 7

[0156] This example uses a method similar to that of Example 7 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0157] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0158] Comparative Example 8

[0159] This example uses a method similar to that of Example 8 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0160] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0161] Comparative Example 9

[0162] This example uses a method similar to that of Example 9 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0163] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0164] Comparative Example 10

[0165] This example uses a method similar to that of Example 10 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0166] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0167] Comparative Example 11

[0168] This example uses a method similar to that of Example 11 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0169] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0170] Comparative Example 12

[0171] This example uses a method similar to that of Example 12 to prepare titanium-based self-doped lithium battery negative electrode material TiNb 2 O 7 The difference is that commercial TiO 2 With Nb 2 O 5 mix.

[0172] The performance of the battery material prepared in this comparative example is shown in Table 1.

[0173] Table 1. Battery material properties of various examples and comparative examples

[0174] First discharge specific capacity / (mAh / g) Capacity after 100 cycles (0.1C) Example 1 223.6 218.5 Example 2 210.9 199.6 Example 3 225.3 214.3 Example 4 213.5 209.7 Example 5 221.3 213.4 Example 6 203.9 188.6 Example 7 206.8 195.4 Example 8 215.8 200.3 Example 9 210.4 201.6 Example 10 220.9 204.91 Embodiment 11 211.1 199.3 Example 12 217.4 206.6 Comparative Example 1 242.4 130.3 Comparative Example 2 257.9 140.4 Comparative Example 3 232.8 141.2 Comparative Example 4 241.3 132.0 Comparative Example 5 218.6 129.2 Comparative Example 6 225.4 142.7 Comparative Example 7 238.8 124.7 Comparative Example 8 246.1 165.2 Comparative Example 9 240.1 157.7 Comparative Example 10 245.7 169.3 Comparative Example 11 238.8 149.2 Comparative Example 12 240.1 158.3

[0175] It can be seen from Table 1 that the aluminum self-doped TiNb prepared by the present invention 2 O 7 Lithium battery negative electrode materials compared to undoped TiNb 2 O 7 For the negative electrode material, although the initial specific capacity is slightly lower than that of undoped commercial materials, the material has excellent cycle stability during the subsequent charging and discharging process.

[0176] The present invention has been described in detail above. For those skilled in the art, without departing from the purpose and scope of the present invention, can implement the present invention in a wider range under equivalent parameters, concentrations and conditions. Although the present invention provides specific embodiments, it should be understood that the present invention can be further improved. In a word, according to the principle of the present invention, the application is intended to include any changes, uses or improvements to the present invention, including departing from the disclosed scope in the application and the changes made with conventional techniques known in the art.

Claims

1. A self-doped TiNb for lithium battery prepared from waste titanium dioxide carrier 2 O 7 Negative electrode material method, It is characterized in that The steps include: S1, respectively, the waste titanium dioxide carrier is converted into TiO with a Ti content of ≥95% and an Al content of 0.1-4.0%. 2 powder; Calculated as oxide, the TiO 2 The impurity V content in the powder is controlled at 0.01%~0.3%; Calculated as oxide, the TiO 2 The impurity W content in the powder is controlled at 0.1~1.0%; The waste titanium dioxide carrier is a waste catalyst using titanium dioxide as a catalyst carrier; The conversion step in step S1 includes: S10, physically crushing, washing and ball-milling the waste titanium dioxide carrier to obtain waste titanium dioxide carrier powder; S11, mixing the waste titanium dioxide carrier powder and the sodium-containing roasting material and roasting them to convert the titanium dioxide into sodium titanium salt to obtain clinker; S12, using water as a leaching agent, subjecting the clinker to a first leaching, collecting the first leached residue, and drying it; S13, using acid as a leaching agent, leaching the first leaching residue for a second time, and collecting a second leaching liquid; S14, adding an alkaline reagent to the second leaching solution, collecting the precipitate, drying and calcining it in sequence, to obtain the TiO 2 powder; The sodium roasting material is sodium carbonate or sodium hydroxide; The mass ratio of the waste titanium dioxide carrier powder to the sodium-calcined material is 1:(2-3); The calcination in step S11 is performed in an air atmosphere at a calcination temperature of 650° C. to 850° C.; The temperature of the first leaching is 60°C to 90°C; The first leaching time is 1 h to 10 h; The acid is H 2 SO 4 , one or more of HCl; The acid exists in the form of its aqueous solution with a concentration of 3 to 5 mol / L; The temperature of the second leaching is 80-90°C; The second leaching time is 5 to 24 hours; The alkaline reagent is ammonia, Na 2 CO 3 , NaOH, urea or more; The alkaline reagent is added in the form of an aqueous solution with a concentration of 1 to 100 g / L; The aqueous solution of the alkaline reagent is dripped at a rate of 0.5-1 mL / min; The amount of the alkaline agent added is controlled so that the pH value of the system is 2.5-5; S2, the TiO 2 Powder and Nb 2 O 5 The powders were mixed and calcined, and the generated Al self-doped TiNb 2 O 7 , to obtain the self-doped TiNb 2 O 7 Negative electrode material.

2. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to claim 1 2 O 7 Negative electrode material method, Features: Calculated as oxide, the TiO 2 The Al content in the powder is 0.1~3.0%.

3. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to claim 2 2 O 7 Negative electrode material method, Features: Calculated as oxide, the TiO 2 The impurity V content in the powder is controlled at 0.01~0.1%; Calculated as oxide, the TiO 2 The impurity W content in the powder is controlled at 0.1~0.5%.

4. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to any one of claims 1 to 3 2 O 7 Negative electrode material method, Features: The mass percentage of titanium dioxide in the waste titanium dioxide carrier is 70% to 95%; The mass percentage of aluminum oxide in the waste titanium dioxide carrier is 4% to 10%; The mass percentage of tungsten trioxide in the waste titanium dioxide carrier is 2% to 3%; The mass percentage of vanadium pentoxide in the waste titanium dioxide carrier is 1% to 3%.

5. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to claim 1 2 O 7 Negative electrode material method, Features: The ball mill is passed through a 325 mesh sieve; In step S11, the calcination and holding time is 6 h.

6. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to claim 1 2 O 7 Negative electrode material method, Features: Step S11 also includes passing the clinker through a 200-mesh sieve for standby use; The material-liquid ratio of the first leaching is 1g:30mL; The first leached residue is dried by vacuum drying at a temperature of 60° C. to 90° C. for 12 hours.

7. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to claim 1 2 O 7 Negative electrode material method, Features: The material-liquid ratio of the second leaching is 1g:30mL; The drying in step S14 is vacuum drying, the drying temperature is 60-80° C., and the drying time is 12-24 h; The calcination in step S14 is carried out in an air atmosphere, at a calcination temperature of 600° C., and at a holding time of 3 to 5 h.

8. The method for preparing self-doped TiNb for lithium battery using waste titanium dioxide carrier according to any one of claims 1 to 3 2 O 7 Negative electrode material method, Features: The TiO 2 Powder with the Nb 2 O 5 The molar ratio of the powder is 1.05:1; The TiO 2 Powder with the Nb 2 O 5 After mixing the powders, pass through a 325-mesh sieve; The calcination in step S2 is performed in an air atmosphere, the calcination temperature is 1100° C. to 1300° C., and the holding time is 8 to 12 hours.

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