Method for detecting density of gel battery electrolyte and error correction method thereof

Abstract

The application discloses a detection method and error correction method for colloid battery electrolyte density, and the detection method comprises the following steps: stirring, stirring the colloidal electrolyte into a semi-colloid state; suction filtration, suction filtering the stirred electrolyte to obtain a preliminary sulfuric acid electrolyte; standing, standing the preliminary sulfuric acid electrolyte obtained by suction filtration; filtering, filtering the sulfuric acid electrolyte after standing to obtain dilute sulfuric acid; and detection calculation, detecting the mass and volume of the dilute sulfuric acid or obtaining the density of the electrolyte by titration. The detection method for colloid battery electrolyte density of the application uses detection instead of estimation, the accuracy of the detected electrolyte density is high, and the corresponding correction method is provided, so that the detection result is more accurate.

Description

Technical Field

[0001] This invention belongs to the field of detection technology for gel battery electrolytes, and specifically relates to a method for detecting the density of gel battery electrolytes and its error correction method. Background Technology

[0002] Gel batteries use gel electrolyte, which is prepared using silica, water, acid, and other related auxiliary materials. The gel electrolyte is prepared in a reaction vessel with a built-in stirring device. After the gel is added to the battery, it solidifies into a jelly-like state and is distributed on the surface of the battery separator. At the same time, after the battery is injected with electrolyte, it needs to be charged. The chemical reaction and water loss during the charging process will change the original sulfuric acid density in the gel electrolyte. After the electrolyte is added to the battery, the gel itself will also have a coagulation reaction. The sulfuric acid, as the electrolyte, is wrapped in a porous network of silica sol. The electrolyte has a jelly-like structure, and the density of the electrolyte, i.e., sulfuric acid, cannot be directly detected. Previously, the industry could only estimate it using the empirical formula (1) for the open circuit of the battery; however, the density estimation by this method has a large error.

[0003] Electrolyte density (g / ml) = Battery open-circuit voltage - 0.85 (1)

[0004] For example, if the open-circuit voltage of the battery is 2.15V, then the estimated electrolyte density inside the battery is 2.15 - 0.85 = 1.3g / ml. Summary of the Invention

[0005] This invention addresses the shortcomings of existing technologies by providing a method for detecting the electrolyte density of gel batteries and a method for correcting its error. The specific technical solution is as follows:

[0006] A method for detecting the electrolyte density of a gel battery, the method comprising:

[0007] Stir the gelatinous electrolyte to achieve a semi-colloidal state.

[0008] The stirred electrolyte is filtered to obtain a preliminary sulfuric acid electrolyte.

[0009] Allow the preliminary sulfuric acid electrolyte obtained by vacuum filtration to stand;

[0010] Filtration: The sulfuric acid electrolyte after standing is filtered to obtain dilute sulfuric acid;

[0011] The detection and calculation are performed by measuring the mass and volume of the dilute sulfuric acid or by titration to obtain the density of the electrolyte.

[0012] Furthermore, the semi-colloidal state is a state in which the electrolyte exhibits a free liquid state.

[0013] Furthermore, the settling time is 5-30 minutes.

[0014] An error correction method for detecting the electrolyte density of a gel battery, the error correction method comprising:

[0015] Prepare a colloidal electrolyte using sulfuric acid of known density;

[0016] The density of sulfuric acid in the prepared colloidal electrolyte was measured.

[0017] The error coefficient is obtained by comparing the known sulfuric acid density of the provided standard sample with the detected sulfuric acid density.

[0018] The measured battery electrolyte density is corrected using the aforementioned error coefficient.

[0019] Further, the detection of the sulfuric acid density in the colloidal electrolyte includes:

[0020] Stir the prepared gel-like electrolyte into a semi-colloid state.

[0021] The stirred electrolyte is filtered to obtain a preliminary sulfuric acid electrolyte.

[0022] Allow the preliminary sulfuric acid electrolyte obtained by vacuum filtration to stand;

[0023] Filtration: The sulfuric acid electrolyte after standing is filtered to obtain dilute sulfuric acid;

[0024] The detection and calculation are performed by measuring the mass and volume of the dilute sulfuric acid or by titration to obtain the density of the electrolyte.

[0025] Furthermore, the method of obtaining the error coefficient by comparing the known standard sulfuric acid density with the detected sulfuric acid density includes,

[0026] Calculate the difference between the known sulfuric acid density of the prepared standard sample and the detected sulfuric acid density;

[0027] Furthermore, the colloidal electrolyte is prepared using standard sulfuric acid of known density, and the content of the colloidal electrolyte by weight ratio comprises:

[0028] Deionized water 40-60%, sulfuric acid 35-50%, silica 5-9%, gelling agent 1-3%.

[0029] The beneficial effects of this invention are: the method for detecting the electrolyte density of a gel battery uses detection instead of estimation, resulting in high accuracy of the detected electrolyte density. Furthermore, it is equipped with a corresponding calibration method to ensure even more precise detection results. Detailed Implementation

[0030] 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 in conjunction with the embodiments of the present invention. Obviously, the described embodiments are only some embodiments of the present invention, 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.

[0031] A method for detecting the electrolyte density of a gel battery, the method comprising the following steps:

[0032] Step 1: Stir, and stir the gel-like electrolyte into a semi-colloid state;

[0033] Specifically, the colloidal electrolyte is stirred until it reaches a semi-colloidal state where it can flow (i.e., free liquid appears). The stirring process first disrupts the porous network structure of silica in the colloidal electrolyte, transforming the jelly-like block into a semi-colloidal state.

[0034] Step 2: Filtration. The stirred electrolyte is filtered to obtain a preliminary sulfuric acid electrolyte.

[0035] Specifically, the stirred colloidal electrolyte is filtered using a vacuum filtration device. The main purpose of the filtration is to remove silica from the colloidal electrolyte.

[0036] Step 3: Let stand, let the preliminary sulfuric acid electrolyte obtained by vacuum filtration stand;

[0037] Specifically, the settling time is 5-30 minutes, and the purpose of settling is to allow the silica that was not completely removed by filtration in the electrolyte to precipitate.

[0038] Step 4: Filtration. The sulfuric acid electrolyte after standing is filtered to obtain dilute sulfuric acid.

[0039] The filtration process primarily aims to further remove the precipitated silica, removing as much silica as possible from the colloidal electrolyte.

[0040] Step 5: Detection and calculation, by detecting the mass and volume of the dilute sulfuric acid or by obtaining the density of the electrolyte through titration.

[0041] Specifically, the density of the electrolyte is detected by two methods: one is to detect the mass and volume of dilute sulfuric acid and obtain the density of the electrolyte by the mass-to-volume ratio;

[0042] Another method is to determine the concentration of the titrated alkali by titration, then calculate the percentage content of sulfuric acid, and finally obtain the density of the acid by comparing the sulfuric acid density with the percentage content. The comparison table of sulfuric acid density with percentage content is shown in Table (1) below.

[0043] Considering that the colloidal electrolyte is a mixture of silica and dilute sulfuric acid, and silica itself is alkaline, some sulfuric acid will not be separated; at the same time, the sulfuric acid electrolyte obtained by vacuum filtration will adhere to the filter paper used for filtration, resulting in a difference in the density of the actual dilute sulfuric acid obtained and the sulfuric acid inside the colloidal electrolyte; therefore, the correction method of the present invention is provided.

[0044] An error correction method for detecting the electrolyte density of a gel battery, the error correction method comprising the following steps:

[0045] Step 1: Prepare a colloidal electrolyte using sulfuric acid of known density;

[0046] The colloidal electrolyte is prepared using standard sulfuric acid of known density, and the content of the colloidal electrolyte by weight ratio comprises:

[0047] The mixture contains 40-60% deionized water, 35-50% sulfuric acid, 5-9% silica, and 1-3% gelling agent. Preferably, it contains 50% deionized water, 40% sulfuric acid, 8% silica, and 2% gelling agent.

[0048] Specifically, take a set of standard sulfuric acid samples with known density, preferably with a density similar to that of the battery electrolyte being tested; for example, the density of the standard sulfuric acid sample is pn, and the density of the battery electrolyte being tested is pm; mix the standard sulfuric acid sample with deionized water, silica and a gelling agent to prepare a colloidal electrolyte.

[0049] Step 2: Detect the sulfuric acid density in the prepared colloidal electrolyte;

[0050] Specifically, the density of colloidal electrolytes prepared from standard samples is detected using the detection method of the present invention. For example, the detection is performed according to the following method:

[0051] Stir the prepared gel-like electrolyte into a semi-colloid state.

[0052] The stirred electrolyte is filtered to obtain a preliminary sulfuric acid electrolyte.

[0053] Allow the preliminary sulfuric acid electrolyte obtained by vacuum filtration to stand;

[0054] Filtration: The sulfuric acid electrolyte after standing is filtered to obtain dilute sulfuric acid;

[0055] The detection and calculation are performed by measuring the mass and volume of the dilute sulfuric acid or by titration to obtain the density of the electrolyte.

[0056] For example, the density of the electrolyte provided is p1.

[0057] Step 3: Obtain the error coefficient by comparing the known sulfuric acid density of the prepared standard sample with the detected sulfuric acid density;

[0058] Specifically, including,

[0059] The difference between the known standard sulfuric acid density and the detected sulfuric acid density is calculated, i.e., pn-p1, and the resulting error coefficient is t.

[0060] As another protection scheme of the present invention, in order to improve the detection accuracy, multiple sets of the prepared colloidal electrolyte can be prepared for detection, and then multiple differences are measured. The average value of the multiple differences is calculated and the average value is used as the error coefficient. For example, six sets of prepared colloidal electrolytes are taken, but not limited to six sets, and the densities of the prepared electrolytes are p1, p2, p3, p4, p5, and p6, respectively. pn-p1, pn-p2, pn-p3, pn-p4, pn-p5, and pn-p6 are calculated to obtain six differences. The average of the six differences is t, for example, and is used as the error coefficient.

[0061] Step 4: Correct the detected battery electrolyte density using the aforementioned error coefficient;

[0062] For example, the battery electrolyte density detected by the present invention is corrected by the obtained error coefficient, wherein the battery electrolyte density is pm+t.

[0063] Implementation Case:

[0064] I. Testing of battery electrolytes, as part of the testing group;

[0065] The testing equipment includes: 1. a funnel; 2. a filtration flask; 3. a vacuum pump;

[0066] 1. Remove 100g of the adhesive block to be tested from the battery;

[0067] 2. Place the gel block into a glass and stir with a glass rod for 3-4 minutes until the gel block becomes semi-solid (with free liquid appearing);

[0068] 3. Connect the filtration flask and the vacuum pump funnel; place filter paper in the G4 funnel, pour the glue solution onto the filter paper, ensuring the glue solution completely covers the filter paper to guarantee the suction efficiency (avoiding air leakage); turn on the vacuum pump (vacuum pressure -0.1Mpa), and obtain 5-10ml of sulfuric acid solution through filtration.

[0069] 4. Let the sulfuric acid solution stand for 5 minutes; take 1.5g of the filtrate and determine the mass fraction of sulfuric acid by titration with sodium hydroxide.

[0070] 5. Titration with sulfuric acid solution:

[0071] Reagents: Methyl red-methylene blue mixed indicator: (mass ratio 2:1) g / L (1+1 ethanol solution); Sodium hydroxide standard solution: C = 0.5 mol / L;

[0072] Analysis steps:

[0073] Take 1.5 g (accurate to 0.001 g) of the filtrate and place it in a beaker. Add 100 mL of water and 2 drops of methyl red-methylene blue mixed indicator. Titrate with sodium hydroxide standard solution until the solution changes from purple-red to gray-green. 25.48 mL of sodium hydroxide standard solution is consumed.

[0074] The mass fraction of sulfuric acid = C × V × 0.04904 ÷ m × 100%

[0075] In the formula: C—concentration of sodium hydroxide standard solution, mol / L; V—volume of sodium hydroxide standard solution consumed by the sample, mL; m—mass of the sample, g

[0076] The mass fraction of sulfuric acid = 0.5 x 25.48 x 0.04904 / 1.5 x 100% = 41.65%

[0077] By referring to the sulfuric acid density and mass fraction comparison table, the density of a 41.65% sulfuric acid solution is 1.311 g / ml.

[0078] II. Standard Sample Group;

[0079] 1. Using sulfuric acid with a known acid density of 1.310 g / mL and silicon dioxide, etc., according to the same production process as the experimental group, prepare gel blocks containing known electrolyte densities;

[0080] 2. Following the same method, the density of the tested sulfuric acid was found to be 1.306 g / mL. Therefore, the correction factor for the experimental test is 0.004 g / mL.

[0081] III. Final density correction;

[0082] The sulfuric acid density of the test group should be 1.311 + 0.004 = 1.3115 g / ml.

[0083] The method for detecting the electrolyte density of a gel battery according to the present invention uses detection instead of estimation, resulting in high accuracy of the detected electrolyte density. At the same time, it is equipped with a corresponding calibration method to ensure that the detection results are more accurate.

[0084] It should be noted that, in this document, the use of relational terms such as "first" and "second" is merely used to distinguish one entity or operation from another, and does not necessarily require or imply any such actual relationship or order between these entities or operations. Furthermore, the terms "comprising," "including," or any other variations thereof are intended to cover non-exclusive inclusion, such that a process, method, article, or apparatus that comprises a list of elements includes not only those elements but also other elements not expressly listed, or elements inherent to such a process, method, article, or apparatus. Without further limitations, an element defined by the phrase "comprising one..." does not exclude the presence of other identical elements in the process, method, article, or apparatus that includes said element.

[0085] The above embodiments are only used to illustrate the technical solutions of the present invention, and are not intended to limit it. Although the present invention has been described in detail with reference to the foregoing embodiments, those skilled in the art should understand that modifications can still be made to the technical solutions described in the foregoing embodiments, or equivalent substitutions can be made to some of the technical features. Such modifications or substitutions do not cause the essence of the corresponding technical solutions to deviate from the spirit and scope of the technical solutions of the embodiments of the present invention.

[0086] Table 1: Comparison of sulfuric acid density and percentage content

[0087]

Claims

1. A method for detecting the electrolyte density of a gel battery, characterized in that: include: Stir the gelatinous electrolyte to achieve a semi-colloidal state. The stirred electrolyte is filtered to obtain a preliminary sulfuric acid electrolyte. Allow the preliminary sulfuric acid electrolyte obtained by vacuum filtration to stand; Filtration: The sulfuric acid electrolyte after standing is filtered to obtain dilute sulfuric acid; The density of the electrolyte is obtained by detection and calculation through titration. An error correction method for the detection method of electrolyte density in gel batteries, comprising: Prepare a colloidal electrolyte using sulfuric acid of known density; The density of sulfuric acid in the prepared colloidal electrolyte was measured. The error coefficient is obtained by comparing the known sulfuric acid density of the provided standard sample with the detected sulfuric acid density. The error coefficient is used to correct the detected battery electrolyte density; The detection equipment is equipped with a colloidal electrolyte containing sulfuric acid density; including: Stir the prepared gel-like electrolyte into a semi-colloid state. The stirred electrolyte is filtered to obtain a preliminary sulfuric acid electrolyte. Allow the preliminary sulfuric acid electrolyte obtained by vacuum filtration to stand; Filtration: The sulfuric acid electrolyte after standing is filtered to obtain dilute sulfuric acid; The density of the electrolyte is obtained by detection and calculation through titration. The error coefficient is obtained by comparing the known standard sulfuric acid density with the detected sulfuric acid density, including: Calculate the difference between the known sulfuric acid density of the prepared standard sample and the detected sulfuric acid density; The colloidal electrolyte is prepared using standard sulfuric acid of known density, and the content of the colloidal electrolyte by weight ratio comprises: Deionized water 40-60%, sulfuric acid 35-50%, silica 5-9%, and gelling agent 1-3%.

2. The method for detecting the electrolyte density of a gel battery according to claim 1, characterized in that: The semi-colloid is in a state where the electrolyte has free liquid.

3. The method for detecting the electrolyte density of a gel battery according to claim 1, characterized in that: The settling time is 5-30 minutes.

Images