Lithium manganate oblique mixing quality testing method

Abstract

The invention relates to the technical field of oblique mixing quality testing of a lithium battery positive electrode material lithium manganate, in particular to a lithium manganate oblique mixing quality testing method, which comprises the following steps of: taking 1g of mixed lithium manganate material, putting into a 250ml beaker, adding 50ml of purified water and a magnetic stirrer, covering, and stirring on a magnetic stirrer with the rotating speed of 550 for 20 minutes; after standing for 2 minutes, taking supernate, filtering by two layers of filter paper, transferring 10 ml of filtrate into a 250 ml conical flask, adding 40 ml of purified water, firstly adding 2 drops of phenolphthalein, titrating with 0.1001 mol / L hydrochloric acid until the solution is colorless, then adding 2 drops of methyl red, titrating until the solution is orange, boiling for 1 minute, cooling, titrating until the solution is wine red, and filtering to obtain the finished product. Calculating a result according to a formula that the first step of diluted hydrochloric acid is 0.1001 * 0.006941 * 100 * 5 (M + is stored) and the second step of titration consumption is-0.01 * extracted MRC / sample weight; the lithium manganate oblique mixing quality test method is simple and accurate in operation, rapid and efficient, can optimize the process, saves time and labor, improves the test effectiveness and accuracy, and can pre-judge the later material performance to ensure the high quality of lithium manganate.

Description

Technical Field

[0001] This invention relates to the field of oblique mixing quality testing technology for lithium manganese oxide, a cathode material for lithium batteries, specifically a method for oblique mixing quality testing of lithium manganese oxide. Background Technology

[0002] Lithium-ion batteries, as a new energy industry, have been promoted worldwide. Lithium manganese oxide, as a cathode material for lithium-ion batteries, has always been a key research focus and development direction in the industry, and has been widely used in digital products, power tools, electric vehicles, and electric cars. Mixing lithium manganese oxide is one of the most common production processes, with wide applications in many fields such as food, medicine, materials, plastics, fertilizers, and metallurgy. Efficient oblique mixing of powders is essential for product quality; the quality of dry powder oblique mixing directly affects the quality of subsequent products. Therefore, quality inspection of dry powder oblique mixing is crucial.

[0003] Because the quality of lithium manganese oxide during the inclined mixing process is uncertain, the inclined mixing of powder becomes a complex stochastic process. The evaluation and determination of the quality of inclined mixing has always been a challenge for relevant technical personnel. Existing quality detection technologies for lithium manganese oxide inclined mixing have significant difficulties. There is a lack of simple, efficient, rapid, and accurate inclined mixing quality testing methods, and they cannot provide effective support for process optimization. Therefore, in view of the above situation, it is urgent to develop a quality testing method for lithium manganese oxide inclined mixing to overcome the shortcomings in current practical applications. Summary of the Invention

[0004] The purpose of this invention is to provide a method for testing the quality of lithium manganese oxide sludge, so as to solve the problems mentioned in the background art.

[0005] To achieve the above objectives, the present invention provides the following technical solution: A method for testing the mass of lithium manganese oxide slant mixtures includes the following steps: Step 1, Sampling: Take the mixed lithium manganese oxide material as the test sample; Step 2, Stirring and Dissolving: Add purified water and a magnetic stir bar to the sample, cover it, and place it on a magnetic stirrer for stirring. Step 3, Static Filtration: After stirring, let the system stand, take the supernatant for filtration, and collect the filtrate; Step 4, stepwise titration: Take a portion of the filtrate, dilute it with purified water, add phenolphthalein indicator, and titrate with standard hydrochloric acid solution until the solution is colorless; Add methyl red indicator and continue titrating with the hydrochloric acid standard solution until the solution turns orange-yellow; Boil the titrated solution, cool it, and titrate it again with the hydrochloric acid standard solution until the solution turns wine red. Record the amount of hydrochloric acid standard solution consumed in each titration step. Step 5, Result Calculation and Judgment: Calculate the test results according to the preset formula, and determine the mass of the lithium manganese oxide mixture based on the test results; the preset formula includes two calculation steps: The first step is to calculate M+ = concentration of hydrochloric acid standard solution × fixation coefficient × proportionality coefficient 1 × proportionality coefficient 2; The second step calculates the final result as follows: Titration consumption in the second step - Correction factor × Extracted MRC / Sample weight.

[0006] As a further aspect of the present invention: in step 1, the weight of the sample is 0.8-1.2g.

[0007] As a further aspect of the present invention: in step 2, the amount of purified water added is 45-55 ml, the stirring speed of the magnetic stirrer is 500-600 r / min, and the stirring time is 15-25 minutes.

[0008] As a further aspect of the present invention: in step 3, the settling time is 1-3 minutes, and the filtration process uses two layers of filter paper for filtration.

[0009] As a further aspect of the present invention: in step 4, the volume of the filtrate transferred is 8-12 ml, and the amount of purified water added for dilution is 35-45 ml.

[0010] As a further aspect of the present invention: in step 4, the amount of phenolphthalein indicator and methyl red indicator added is 1-3 drops each.

[0011] As a further aspect of the present invention: in step 4, the concentration of the hydrochloric acid standard solution is 0.09-0.11 mol / L, and the hydrochloric acid standard solution is calibrated in the laboratory.

[0012] As a further aspect of the present invention: in step 4, the solution is boiled for 0.5-1.5 minutes, and after boiling, it is cooled to room temperature before the final titration is performed.

[0013] As a further aspect of the present invention: in step 5, the specific parameters of the preset formula are as follows: Fixed coefficient = 0.006941, proportional coefficient 1 = 100, proportional coefficient 2 = 5, correction coefficient = 0.01.

[0014] As a further aspect of the present invention: in step 3, the filtered filtrate is collected in a 25ml beaker; In step 4, the filtrate is transferred using a pipette, and the hydrochloric acid standard solution is a 0.1001 mol / L standard hydrochloric acid solution.

[0015] Compared with the prior art, the beneficial effects of the present invention are: 1. In this invention, 1g of the mixed lithium manganese oxide material is placed in a 250ml beaker, 50ml of purified water and a magnetic stir bar are added, the beaker is capped, and the mixture is stirred on a magnetic stirrer at 550 rpm for 20 minutes. After standing for 2 minutes, the supernatant is filtered through two layers of filter paper into a 25ml beaker. Then, 10ml of the filtrate is transferred to a 250ml conical flask and 40ml of purified water is added. Two drops of phenolphthalein indicator and two drops of methyl red indicator are added sequentially. 0.1001mol / L hydrochloric acid standard solution is used for titration according to the following procedure: "titration until colorless → titration until orange-yellow → boiling and cooling, then titration until alcoholic". The titration is performed in the "red" step, and the final result is calculated according to the formula "dilute hydrochloric acid first step 0.1001×0.006941×100×5 (store M+), second step titration consumption -0.01×extraction MRC / sample weight" to determine the quality of the lithium manganese oxide slant mixture. All operations in this scheme (such as weighing, liquid addition, stirring parameters, filtration method, titration reagent concentration and steps, calculation method) are specific and routine operations, without the need for complex equipment or cumbersome pretreatment processes, achieving a simple, accurate, fast and efficient technical effect. 2. The present invention adopts the "sampling-stirring-filtration-titration-formula calculation" scheme, which can quickly obtain the specific test results of the lithium manganese oxide inclined mixing quality. It does not require repeated experiments or complex detection methods to infer the inclined mixing quality. The inclined mixing process parameters (such as inclined mixing time and speed) can be adjusted directly based on the test results, thereby achieving the technical effect of optimizing the process and saving time and effort. 3. This invention employs a technical solution that precisely controls the sample weight (1g), reagent dosage (50ml of purified water, 40ml of purified water, and 0.1001mol / L hydrochloric acid standard solution), stirring parameters (550 rpm and 20 minutes), and titration endpoint determination criteria (phenolphthalein indicating colorless, methyl red indicating orange-yellow, then wine-red, and re-tipping after boiling and cooling), and calculates the results using a fixed formula. This solution ensures that the test results accurately reflect the quality of the lithium manganese oxide mixture through precise control of multiple stages, avoids test errors caused by unclear operating parameters, achieves a clear understanding of the quality of the mixture, and increases the effectiveness and accuracy of the test. 4. Since the quality of the lithium manganese oxide mixture directly affects the performance of subsequent products, this invention can predict the performance of subsequent lithium manganese oxide materials in processing and use (such as electrochemical stability) based on test results. This eliminates the need to wait until the subsequent products are formed to discover quality problems, thus achieving the technical effect of predicting the approximate performance of subsequent materials in advance based on the quality of the mixture, ensuring the production of high-quality lithium manganese oxide. Detailed Implementation

[0016] The technical solutions in the embodiments of the present invention will be clearly and completely described below. Obviously, the described embodiments are only some embodiments of the present invention, and not all embodiments. Based on the embodiments of the present invention, all other embodiments obtained by those skilled in the art without creative effort are within the scope of protection of the present invention.

[0017] The specific implementation of the present invention will be described in detail below with reference to specific embodiments.

[0018] This invention provides a method for testing the quality of lithium manganese oxide inclined mixtures, which solves the problems existing in the quality detection technology of lithium manganese oxide inclined mixtures. It provides a simple, efficient, fast, and accurate testing method that can help optimize the process. The specific implementation process is as follows: Sample preparation and pretreatment: Take the mixed lithium manganese oxide material, accurately weigh 1g of sample and place it in a 250ml beaker; add 50ml of purified water to the beaker, then place a magnetic stir bar in the beaker, and then cover the beaker to prevent water evaporation or impurities from falling in during the stirring process. Place the covered beaker on a standard laboratory magnetic stirrer, adjust the speed of the magnetic stirrer to 550 r / min, and maintain this speed for 20 minutes.

[0019] This step ensures the target components in the lithium manganese oxide sample are fully dissolved by precisely controlling the sample weight, solvent volume, stirring speed, and time, laying the foundation for subsequent detection. At the same time, fixed operating parameters can avoid test errors caused by human operation differences, thus initially improving the accuracy of the test.

[0020] Filtration: After stirring, stop the magnetic stirrer and let the beaker stand for 2 minutes to allow the undissolved solid particles in the beaker to settle completely; then take the supernatant in the beaker and slowly pour it into a funnel with two layers of filter paper. Filter the supernatant through the funnel into a 25 ml beaker.

[0021] Filtration with two layers of filter paper can effectively remove residual solid impurities from the supernatant, preventing impurities from entering the subsequent titration process and affecting the determination of the titration endpoint. This further ensures the accuracy of the testing process and guarantees that the subsequent titration reaction is only carried out on the target dissolved component.

[0022] Titration procedure: Accurately transfer 10 ml of the filtered liquid using a standard laboratory pipette into a 250 ml Erlenmeyer flask; add 40 ml of purified water to the flask to dilute the filtrate and optimize the titration reaction conditions; then add 2 drops of phenolphthalein indicator to the flask, and titrate the liquid in the flask with a 0.1001 mol / L hydrochloric acid standard solution (the hydrochloric acid standard solution is a laboratory-calibrated 0.1001 mol / L hydrochloric acid solution) until the solution changes from red to colorless, then stop the first titration; Then, add 2 drops of methyl red indicator to the conical flask and continue titrating with the above 0.1001 mol / L hydrochloric acid standard solution until the solution changes from yellow to orange-yellow. At this point, stop the second titration. Boil the solution in the conical flask for 1 minute to remove any carbon dioxide that may be present in the solution and avoid it interfering with the titration endpoint. After the solution cools to room temperature, continue titrating with the above 0.1001 mol / L hydrochloric acid standard solution until the solution turns wine-red. This is the titration endpoint. Record the volume of hydrochloric acid standard solution consumed during this titration.

[0023] This titration process ensures the accuracy and repeatability of the titration reaction by clearly defining the type and amount of indicator, the concentration of hydrochloric acid standard solution, and the endpoint judgment criteria for multi-step titration. Each titration operation is targeted at a specific reaction stage, which can accurately capture the reaction endpoint and provide reliable volume consumption data for subsequent calculations.

[0024] Result Calculation and Quality Judgment: The test results are calculated according to the following formula: The first step of the calculation is: 0.1001×0.006941×100×5 (the result is recorded as M+); The second step calculation formula is: Second step titration consumption - 0.01 × Extraction MRC / Sample weight (Sample weight is the weight of the 1g lithium manganese oxide sample weighed above). The specific numerical result is obtained by calculating the above formula, and the quality of the lithium manganese oxide mixture can be judged based on the result.

[0025] The explicit calculation formula is directly based on the parameters obtained from the aforementioned operations, without the need for additional complex calculations. It can quickly yield the results of the inclined mixing quality assessment, achieving high efficiency in testing. At the same time, the correspondence between the formula and the operation steps ensures that the calculation results can truly reflect the uniformity of the inclined mixing of lithium manganese oxide, providing a direct basis for the assessment of the inclined mixing quality.

[0026] Example 1 A batch of lithium manganese oxide slant mixture was tested using the above-mentioned lithium manganese oxide slant mixture quality test method. The sample weight was 1.0005g. M+ was calculated according to the calculation formula in the first step: 0.1001×0.006941×100×5. Then, using the second calculation formula: 10 - 0.01 × MRC / 1.0005, the final result is 3.45.

[0027] The results can be used to determine the mixing quality of the batch of lithium manganese oxide slant mix. If the results meet the preset high-quality slant mix standard, it means that the batch of slant mix is ​​uniformly mixed and can be used to produce high-quality lithium manganese oxide products. If the results deviate from the standard, the slant mixing process parameters (such as slant mixing time and speed) can be adjusted in reverse according to the test process to achieve process optimization.

[0028] In summary, the lithium manganese oxide inclined mixing quality testing method of the present invention has clear operation steps and fixed parameters, requiring no complex equipment, and can achieve simple, accurate, fast and efficient operation. At the same time, the test results can directly guide the optimization of the inclined mixing process, saving the process of repeated experimentation and adjustment, thus achieving the effect of saving time and effort. Furthermore, the precise control of multiple links and clear judgment criteria greatly improve the effectiveness and accuracy of the test, and can also predict the approximate performance of lithium manganese oxide materials in the later stage through the inclined mixing quality, ensuring the production of high-quality lithium manganese oxide products.

[0029] It should be noted that, in this invention, although the specification describes the embodiments, not every embodiment contains only one independent technical solution. This way of describing the specification is only for clarity. Those skilled in the art should regard the specification as a whole. The technical solutions in each embodiment can also be appropriately combined to form other embodiments that can be understood by those skilled in the art.

Claims

1. A method for testing the mass of lithium manganese oxide slant mixtures, characterized in that, Includes the following steps: Step 1, Sampling: Take the mixed lithium manganese oxide material as the test sample; Step 2, Stirring and Dissolving: Add purified water and a magnetic stir bar to the sample, cover it, and place it on a magnetic stirrer for stirring. Step 3, Static Filtration: After stirring, let the system stand, take the supernatant for filtration, and collect the filtrate; Step 4, stepwise titration: Take a portion of the filtrate, dilute it with purified water, add phenolphthalein indicator, and titrate with standard hydrochloric acid solution until the solution is colorless; Add methyl red indicator and continue titrating with the hydrochloric acid standard solution until the solution turns orange-yellow; Boil the titrated solution, cool it, and titrate it again with the hydrochloric acid standard solution until the solution turns wine red. Record the amount of hydrochloric acid standard solution consumed in each titration step. Step 5, Result Calculation and Judgment: Calculate the test results according to the preset formula, and determine the quality of lithium manganese oxide slant mixture based on the test results; The preset formula includes two calculation steps: The first step is to calculate M+ = concentration of hydrochloric acid standard solution × fixation coefficient × proportionality coefficient 1 × proportionality coefficient 2; The second step calculates the final result as follows: Titration consumption in the second step - Correction factor × Extracted MRC / Sample weight.

2. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 1, the weight of the sample is 0.8-1.2g.

3. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 2, the amount of purified water added is 45-55 ml, the stirring speed of the magnetic stirrer is 500-600 r / min, and the stirring time is 15-25 minutes.

4. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 3, the settling time is 1-3 minutes, and the filtration process uses two layers of filter paper.

5. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 4, the volume of filtrate transferred is 8-12 ml, and the amount of purified water added for dilution is 35-45 ml.

6. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 4, the amount of phenolphthalein indicator and methyl red indicator added is 1-3 drops each.

7. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 4, the concentration of the hydrochloric acid standard solution is 0.09-0.11 mol / L, and the hydrochloric acid standard solution is calibrated in the laboratory.

8. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 4, the solution is boiled for 0.5-1.5 minutes, and after boiling, it is cooled to room temperature before the final titration.

9. The method for testing the mass of lithium manganese oxide oblique mixture according to claim 1, characterized in that, In step 5, the specific parameters of the preset formula are: Fixed coefficient = 0.006941, proportional coefficient 1 = 100, proportional coefficient 2 = 5, correction coefficient = 0.

01.

10. The method for testing the mass of lithium manganese oxide oblique mixture according to any one of claims 1-9, characterized in that, In step 3, the filtered filtrate is collected in a 25ml beaker; In step 4, the filtrate is transferred using a pipette, and the hydrochloric acid standard solution is a 0.1001 mol / L standard hydrochloric acid solution.