Preparation and treatment method and device of lithium-rich manganese-based positive electrode material and lithium battery
By analyzing voltage drop data and doping concentration during the preparation of lithium-rich manganese-based cathode materials, and optimizing the calcination temperature range and doping concentration, the problem of voltage window decay caused by cation doping was solved, and the stability and quality assurance of the materials were achieved.
Patent Information
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- XINXIANG ZHONGTIAN NEW ENERGY TECH CO LTD
- Filing Date
- 2026-03-05
- Publication Date
- 2026-05-29
AI Technical Summary
In existing methods for preparing lithium-rich manganese-based cathode materials, the concentration of doped cations such as Al³⁺ and Mg²⁺ affects the working voltage window, which cannot guarantee the stability of the material.
By analyzing voltage drop data at different calcination temperature ranges, the matching temperature range and doping concentration were determined. Combined with temperature control adjustment range, the preparation process was optimized to ensure material stability.
This enables reliable monitoring within the temperature control range, ensuring the quality of cathode material preparation, reducing the difficulty of temperature control, and improving material stability.
Smart Images
Figure CN122117889A_ABST
Abstract
Description
Technical Field
[0001] This invention belongs to the field of lithium battery technology, and particularly relates to a method and equipment for preparing lithium-rich manganese-based cathode materials, as well as lithium batteries. Background Technology
[0002] Lithium-rich manganese-based cathode materials are considered ideal for next-generation commercial high-energy-density lithium-ion batteries due to their high specific capacity (approximately 250 mAh / g), low cost, and good environmental friendliness. With the increasing demands for energy density in electric vehicles, portable electronic products, and energy storage devices, the application prospects of lithium-rich manganese-based cathode materials are promising.
[0003] Existing methods for preparing lithium-rich manganese-based cathode materials include solid-state methods, co-precipitation methods, sol-gel methods, hydrothermal methods, solvothermal methods, and spray drying methods. However, the above technical solutions have the following technical defects: When preparing lithium-rich manganese-based cathode materials, the attenuation of the working voltage window of the lithium-rich manganese-based cathode materials is affected by the doping concentration of cations such as Al³⁺ and Mg²⁺ in the transition metal layer. Therefore, if the influence of the above factors is ignored during the preparation process, the stability of the lithium-rich manganese-based cathode materials cannot be guaranteed.
[0004] To address the aforementioned technical problems, this application provides a method and apparatus for preparing lithium-rich manganese-based cathode materials, as well as a lithium battery. Summary of the Invention
[0005] To achieve the objectives of this invention, the following technical solution is adopted: Specifically, this application provides a method for preparing lithium-rich manganese-based cathode materials, which includes: S1 uses the preparation and processing data of lithium-rich manganese-based cathode material as a basis to determine the consistency of voltage drop data in various calcination temperature ranges. Based on the consistency, it determines the matching temperature range of the calcination temperature range. Using the doping concentration data corresponding to different matching temperature ranges and the variation of voltage drop data under different doping concentrations, it determines the usable doping concentration in the doping concentration. S2 determines the temperature control adjustment range in the matching temperature range based on the deviation between the available doping concentrations and the matching temperature range data corresponding to the available doping concentrations. S3 uses the consistency of the voltage drop data between the temperature control adjustment range data and the available doping concentration corresponding to the temperature control adjustment range to determine the adjustment scheme for the doping concentration in the temperature control adjustment range.
[0006] Furthermore, the calcination temperature range is determined based on the temperature control range of the lithium-rich manganese-based cathode material during the calcination stage. Specifically, the temperature control range is evenly divided into multiple calcination temperature ranges with a 1-degree Celsius interval.
[0007] Furthermore, the consistency of the voltage drop data is determined based on the consistency of the voltage drop in different cycle intervals during the use of the lithium battery constructed with the lithium-rich manganese-based cathode material, wherein the cycle intervals are divided into multiple cycle intervals with 100 cycles as the dividing interval.
[0008] Furthermore, the method for determining the matching temperature range of the calcination temperature range is as follows: Based on the consistency within the calcination temperature range, determine the consistency of voltage drop in lithium batteries constructed with lithium-rich manganese-based cathode materials within the calcination temperature range during use across different cycle number ranges. Using the aforementioned consistency, the deviation of the voltage drop within different cycle number intervals is determined; Based on the deviation, it is determined whether the calcination temperature range is a matching temperature range.
[0009] Furthermore, the method for determining the doping concentration adjustment scheme within the temperature control adjustment range is as follows: Based on the temperature control adjustment range data, determine the number of temperature control adjustment ranges, use the available doping concentration corresponding to the temperature control adjustment range as the matching concentration, use the deviation between each matching concentration to determine the matching concentration whose deviation from other matching concentrations meets the requirements, and use it as the adjacent matching concentration, and divide the matching concentrations that are adjacent to each other into the same group. Based on the consistency of voltage drop data among the matched concentrations in the combination, the similarity of voltage drop among the matched concentrations in the combination within different cycle number intervals is determined, and based on the similarity, a matching combination in the combination is determined; Based on the similarity between the matching concentration of the matching combination of the temperature control adjustment range and other temperature control adjustment ranges, a general combination in the matching combination is determined. Based on the number of temperature control adjustment ranges and the general combination data in the temperature control adjustment range, an adjustment scheme for the doping concentration in the temperature control adjustment range is determined.
[0010] In a second aspect, the present invention provides a computer device, comprising: a memory and a processor connected in communication, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the above-described method for preparing a lithium-rich manganese-based cathode material when running the computer program.
[0011] Thirdly, the present invention provides a lithium battery, wherein the positive electrode material of the lithium battery is prepared by the above-mentioned method for preparing a lithium-rich manganese-based positive electrode material.
[0012] The beneficial effects of this invention are as follows: Based on the matching temperature range data corresponding to the available doping concentration, the temperature control adjustment range in the matching temperature range is determined. This enables the screening of temperature control adjustment ranges with a large number of available doping concentrations and small deviations between different available doping concentrations. This ensures that even if the monitoring reliability of the doping concentration is poor within the temperature control adjustment range, the preparation quality of the cathode material within the temperature control adjustment range can still be guaranteed.
[0013] By utilizing the consistency of voltage drop data between the available doping concentrations corresponding to the temperature control adjustment ranges, an adjustment scheme for the doping concentration within each temperature control adjustment range is determined. This approach considers the varying difficulty of adjustment across different temperature control adjustment ranges due to the number of ranges. Furthermore, by combining the consistency of voltage drop data between the available doping concentrations corresponding to the temperature control adjustment ranges, the system effectively screens temperature control adjustment ranges with a high degree of overlap between the available doping concentrations and other temperature control adjustment ranges. Reliable adjustment within these temperature control adjustment ranges ensures the quality of the cathode material preparation even if temperature control anomalies occur during the calcination stage.
[0014] Other features and advantages will be set forth in the description which follows, and will be apparent in part from the description, or may be learned by practicing the invention. The objects and other advantages of the invention are realized and obtained through the structures particularly pointed out in the description and the drawings.
[0015] To make the above-mentioned objects, features and advantages of the present invention more apparent and understandable, preferred embodiments are described below in detail with reference to the accompanying drawings. Attached Figure Description
[0016] The above and other features and advantages of the present invention will become more apparent from a detailed description of exemplary embodiments thereof with reference to the accompanying drawings.
[0017] Figure 1 This is a flowchart of a method for preparing lithium-rich manganese-based cathode materials; Figure 2 This is a flowchart illustrating the method for determining the matching temperature range within a calcination temperature range. Figure 3 This is a flowchart illustrating the method for determining the temperature control adjustment range within a matching temperature range. Detailed Implementation
[0018] Exemplary embodiments will now be described more fully with reference to the accompanying drawings. However, these exemplary embodiments can be implemented in many forms and should not be construed as limited to the embodiments set forth herein; rather, they are provided so that the invention will be thorough and complete, and the concept of the exemplary embodiments will be fully conveyed to those skilled in the art. The same reference numerals in the drawings denote the same or similar structures, and therefore their detailed description will be omitted.
[0019] The terms “a,” “one,” “the,” and “the” are used to indicate the existence of one or more elements / components / etc.; the terms “including” and “having” are used to indicate an open-ended meaning of inclusion and that other elements / components / etc. may exist in addition to the listed elements / components / etc.
[0020] Example 1 To solve the above problems, according to one aspect of the present invention, such as Figure 1 As shown, a method for preparing a lithium-rich manganese-based cathode material is provided, specifically including: S1 uses the preparation and processing data of lithium-rich manganese-based cathode material as a basis to determine the consistency of voltage drop data in various calcination temperature ranges. Based on the consistency, it determines the matching temperature range of the calcination temperature range. Using the doping concentration data corresponding to different matching temperature ranges and the variation of voltage drop data under different doping concentrations, it determines the usable doping concentration in the doping concentration. Furthermore, the calcination temperature range is determined based on the temperature control range of the lithium-rich manganese-based cathode material during the calcination stage. Specifically, the temperature control range is evenly divided into multiple calcination temperature ranges with a 1-degree Celsius interval.
[0021] Furthermore, the consistency of the voltage drop data is determined based on the consistency of the voltage drop in different cycle intervals during the use of the lithium battery constructed with the lithium-rich manganese-based cathode material, wherein the cycle intervals are divided into multiple cycle intervals with 100 cycles as the dividing interval.
[0022] Specifically, such as Figure 2As shown, the method for determining the matching temperature range of the calcination temperature range is as follows: From a number of finely divided calcination temperature ranges, a matching temperature range was selected that can produce lithium-rich manganese-based cathode materials with excellent voltage decay characteristics.
[0023] The core logic lies in conducting long-cycle tests on lithium batteries constructed from lithium-rich manganese-based cathode materials prepared at different calcination temperatures, analyzing their voltage drop behavior at various cycle stages (i.e., different cycle count ranges). Based on the consistency of voltage drop, the deviation in voltage decay between different batteries is quantitatively evaluated. If the voltage decay deviation between batteries is controlled within a qualified range at all cycle stages within a calcination temperature range, then this temperature range is considered a suitable temperature range for stably producing high-quality materials.
[0024] Based on the consistency within the calcination temperature range, determine the consistency of voltage drop in lithium batteries constructed with lithium-rich manganese-based cathode materials within the calcination temperature range during use across different cycle number ranges. Using the aforementioned consistency, the deviation of the voltage drop within different cycle number intervals is determined; Based on the deviation, it is determined whether the calcination temperature range is a matching temperature range.
[0025] It is understood that the deviation is determined based on the maximum value of the voltage deviation between the specified cycle number range for lithium batteries constructed with different lithium-rich manganese-based cathode materials.
[0026] It should be noted that when there is no cycle number range where the deviation of voltage drop does not meet the requirements, the calcination temperature range is determined to be the matching temperature range.
[0027] In one possible embodiment, if the deviation of the voltage drop within the cycle interval is less than 0.01V, then the deviation of the voltage drop within the cycle interval is determined to meet the requirement.
[0028] A research and development project on lithium-rich manganese-based cathode materials aims to find the optimal calcination temperature for achieving consistent battery voltage decay. Researchers divided the calcination temperature range of 800℃ to 900℃ into 1℃ intervals, resulting in 100 calcination temperature ranges. Within each temperature range, five identical coin cells were fabricated for long-term cycle testing, with a total of 2000 cycles.
[0029] Preset acceptable threshold: The deviation of voltage drop must be less than 0.01V for the battery to be considered to be of acceptable consistency in this cycle stage.
[0030] Step 1: For each calcination temperature range, record the voltage drop data within each cycle count range. Taking the temperature range T=820℃ as an example, in the cycle count range N=[0,100], the voltage drops of the five batteries are 0.15V, 0.16V, 0.15V, 0.17V, and 0.15V, respectively, showing some dispersion. In N=[100,200], the data are 0.28V, 0.29V, 0.28V, 0.30V, and 0.28V. This continues until N=[1900,2000]. These data reflect the consistency of voltage decay at different life stages of the battery at this temperature.
[0031] Step 2: Based on the above data, calculate the voltage drop deviation for each cycle interval.
[0032] For T=820℃: When N=[0,100], the maximum value is 0.17V, the minimum value is 0.15V, and the deviation is 0.02V.
[0033] When N=[100,200], the maximum value is 0.30V, the minimum value is 0.28V, and the deviation is 0.02V.
[0034] When N=[1900,2000], the maximum value is 0.85V, the minimum value is 0.83V, and the deviation is 0.02V.
[0035] Calculations showed that for T=820℃, the deviation was stable at around 0.02V in almost all cyclic intervals.
[0036] Step 3: Based on the deviation of each cycle interval, determine whether the temperature interval is a matching temperature interval.
[0037] The deviation of each cycle interval is compared with the acceptable threshold of 0.01V. For T=820℃, the deviation (0.02V) of all cycle intervals is greater than 0.01V, meaning there are "cycle intervals where the voltage drop deviation does not meet the requirement" (in fact, none of the intervals meet this requirement). Therefore, according to the judgment logic of "when there is no cycle interval where the voltage drop deviation does not meet the requirement, the calcination temperature interval is determined to be a matching temperature interval," there are a large number of intervals at T=820℃ that do not meet the requirement, and thus they are judged as unmatched temperature intervals.
[0038] Next, we examined another temperature range, T=845℃. The deviation across all 20 cycle intervals was less than 0.01V. This means that the voltage decay behavior of the batteries prepared at T=845℃ was highly consistent across all five batteries at any stage of their 2000-cycle lifespan. Therefore, this calcination temperature range of T=845℃ was ultimately determined as the matching temperature range, serving as the preferred process parameter for subsequent pilot-scale production and industrial-scale manufacturing.
[0039] In another embodiment, the method for determining the matching temperature range of the calcination temperature range is as follows: Based on the consistency within the calcination temperature range, determine the consistency of voltage drop in lithium batteries constructed with lithium-rich manganese-based cathode materials within the calcination temperature range during use across different cycle number ranges. Using the aforementioned consistency, the deviation of the voltage drop within different cycle number intervals is determined; Based on the deviation, the average value of the voltage drop deviation is determined within different cycle number intervals, and based on the average value, it is determined whether the calcination temperature range is a matching temperature range.
[0040] It should be noted that when the average value is less than the preset deviation threshold, the calcination temperature range is determined to be the matching temperature range.
[0041] It should be noted that the doping concentration refers to the concentration of aluminum ions doped during the co-precipitation stage before calcination.
[0042] It should be noted that the doping concentration corresponding to the matching temperature range is the aluminum ion doping concentration when the deviation of the voltage drop within the matching temperature range meets the requirements, that is, the aluminum ion doping concentration when the deviation of the voltage drop in each cycle range meets the requirements.
[0043] Specifically, the method for determining the available doping concentration in the doping concentration is as follows: Based on the doping concentration data corresponding to different matching temperature ranges, the matching temperature range corresponding to the doping concentration is determined and used as the matching range of the doping concentration. Based on the variation of voltage drop data between each matching interval, the similarity of voltage drop in different cycle number intervals between each matching interval is determined. By utilizing the similarity of voltage drop across different cycle number ranges in each matching interval, it is determined whether the doping concentration is a usable doping concentration.
[0044] It should be noted that the matching interval is the matching temperature interval of the doping concentration that belongs to the matching temperature interval.
[0045] It is understood that the voltage drop is determined based on the voltage drop of the positive electrode voltage of the lithium battery within the cycle number range.
[0046] Specifically, if the number of matching intervals for the doping concentration is too small, i.e. less than the preset interval number threshold, then if the temperature control accuracy during the calcination process is not good, the overall quality may be affected. Therefore, it is determined that the doping concentration is not a usable doping concentration.
[0047] In one possible embodiment, if the number of matching intervals for the doping concentration is less than 3, then the doping concentration is determined not to be an available doping concentration.
[0048] Preset interval number threshold: A pre-set minimum number used to measure whether there are enough available temperature windows (e.g., 3) for a certain doping concentration. If the number of matching intervals is less than this threshold, it means that the doping concentration is extremely sensitive to temperature and can only produce qualified materials within a very narrow temperature range. The process window is too narrow, which is not conducive to temperature control in industrial production. Therefore, it is determined to be an unusable doping concentration.
[0049] This is the first screening step, quickly eliminating doping concentrations with excessively narrow process windows to ensure that the concentrations examined later have a certain degree of process tolerance.
[0050] The preset threshold for the number of intervals is 3. There is only one matching interval for a doping concentration of 1.0% (e.g., [842, 843)℃), which is less than 3, and is therefore directly determined not to be a usable doping concentration. There are two matching intervals for a doping concentration of 1.5%, which is also less than 3, and are similarly excluded. There are four matching intervals for a doping concentration of 2.0%, so the process proceeds to the next step.
[0051] Additionally, it is understood that if the number of matching intervals for the doping concentration is not less than a preset interval number threshold, it is necessary to further determine the interval between the endpoints of the matching intervals. If there are no adjacent matching intervals for the doping concentration, that is, if the maximum value of the endpoint of one matching interval belongs to the minimum value of the endpoint of another matching interval, then it is determined that the doping concentration does not belong to the available doping concentration.
[0052] Furthermore, if there are adjacent matching intervals for the doping concentration, but there are no matching intervals where the voltage drop is similar across different cycle number intervals, then the doping concentration is determined not to be a usable doping concentration.
[0053] Adjacent matching intervals: These refer to two matching intervals that are consecutive on the temperature axis, meaning the maximum temperature of one interval is exactly equal to the minimum temperature of the other. For example, the intervals [840, 841) and [841, 842) are adjacent. If no such adjacent relationship exists between any matching intervals, and they are separated from each other (with temperature gaps in between), it indicates that the usable temperature window for that doping concentration is discrete and discontinuous, making process control difficult, and thus it is determined to be an unusable doping concentration.
[0054] A continuous temperature window means that the doping concentration is less sensitive to temperature, allowing for continuous temperature adjustment within a certain range while still obtaining acceptable products. Discrete windows, on the other hand, indicate that success is only possible at a few specific, isolated temperature points, resulting in smaller process tolerances and making them unsuitable for actual production.
[0055] There are four matching intervals for a doping concentration of 2.0%: [840, 841), [841, 842), [845, 846), and [846, 847) °C. The first two are adjacent, and the last two are adjacent, but there is a gap between the two groups (no matching interval between 842 and 845 °C), so overall there are cases where they are not adjacent. According to the logic of this sub-step, if no pair of adjacent intervals exists, it is directly excluded. However, there are adjacent pairs here, so it is necessary to further determine that "if there are no matching intervals with similar voltage drops across different cycle count intervals, then it is determined that it is not a usable doping concentration." In fact, the complete logic of sub-step 3.2 is: if there are no adjacent matching intervals for the doping concentration, it is directly determined to be unusable; if there are adjacent matching intervals, then proceed to the next step to determine if there are similar matching intervals. Therefore, in this example, there are adjacent intervals, and the next sub-step needs to be performed.
[0056] Similar voltage drop across different cycle count ranges: This means that the difference in voltage drop between batteries prepared in two matching ranges is less than a preset similarity threshold (e.g., 0.003V) across all cycle count ranges from initial setup to aging. Two ranges that meet this condition are called similar matching ranges.
[0057] Adjacent temperature windows may be continuous in temperature, but their electrochemical aging behaviors may not be consistent due to factors such as material phase transitions. Only those windows that are not only adjacent in temperature but also highly consistent in performance throughout the entire life cycle can truly demonstrate that the process at that doping concentration has high repeatability and robustness.
[0058] For a doping concentration of 2.0%, we examine adjacent interval pairs: A = [840, 841) and B = [841, 842). We calculate the difference in voltage drop between the two intervals across all cycles (e.g., every 100 cycles). Assuming the difference is less than 0.003V across all cycles, A and B are considered similarly matched intervals. Examining another pair of adjacent intervals, C = [845, 846) and D = [846, 847), we find that the difference exceeds 0.003V in some cycles; therefore, C and D do not constitute similarly matched intervals.
[0059] In one possible embodiment, if the voltage drop of the two matching intervals in different cycle number intervals is less than 0.003V, then the voltage drop of the two matching intervals in different cycle number intervals is determined to be similar.
[0060] It should be noted that when there are matching intervals where the voltage drop is similar in different cycle number intervals, the matching intervals where the voltage drop is similar in different cycle number intervals are taken as similar matching intervals. Based on the sum of the number of similar matching intervals and matching intervals, it is determined whether the doping concentration is a usable doping concentration.
[0061] It is understood that when the sum of the number of similar matching intervals and the number of matching intervals is greater than a preset number threshold, the doping concentration is determined to be an available doping concentration.
[0062] In one possible embodiment, when the sum of the number of similar matching intervals and the number of matching intervals is greater than 5, the doping concentration is determined to be an available doping concentration.
[0063] The sum of similar matching intervals and the number of matching intervals: This is a comprehensive indicator. In specific calculations, matching intervals that constitute a similar relationship are treated as a whole, and then the number of other isolated (but potentially qualified) matching intervals is added. Clusters of similar matching intervals are considered, and the number of intervals within these clusters is counted. This number is then added to the number of other matching intervals that are not similar to any other interval, resulting in a sum. This sum is then checked to see if it exceeds a preset threshold (e.g., 5). If it does, the doping concentration is determined to be a usable doping concentration.
[0064] Preset quantity threshold: A pre-set value used to measure whether the total number of temperature windows with high consistency at this doping concentration is sufficient to ensure the tolerance and stability of the process.
[0065] This is the final decision-making stage. If, at a given doping concentration, multiple temperature windows are not only continuous in temperature but also highly similar in performance, then these windows together constitute a "process stability region." The larger this stability region (i.e., the more intervals there are), the higher the tolerance of the doping concentration to temperature fluctuations, and the more suitable it is for large-scale production.
[0066] By quantifying the size of the stability region, usable doping concentrations with wide process windows and good performance consistency are finally selected, providing the optimal combination of process parameters for industrial production.
[0067] Continuing with the previous example, a doping concentration of 2.0% has four matching intervals: A, B, C, and D. A and B are similar matching intervals (forming a similar pair), while C and D are dissimilar (and C is also dissimilar to A / B). Therefore, there are two similar matching intervals (A and B), and the total number of matching intervals is 4. The number of intervals covered by the similar matching intervals (2) plus the total number of matching intervals (4) equals 6. Assuming the preset threshold is 5, then 2 + 4 = 6 > 5, which is considered a usable doping concentration. However, in this example, the sum is 6, which is greater than 5, therefore, a doping concentration of 2.0% is considered a usable doping concentration.
[0068] S2 determines the temperature control adjustment range in the matching temperature range based on the deviation between the available doping concentrations and the matching temperature range data corresponding to the available doping concentrations. Specifically, such as Figure 3 As shown, the method for determining the temperature control adjustment range within the matched temperature range is as follows: Using the matching temperature range data corresponding to the available doping concentration, determine the available doping concentration in the matching temperature range and use it as the matching concentration; Based on the deviation between the matched concentrations, determine the amount of deviation between each matched concentration; By using the deviation between each matched concentration, it is determined whether the matched temperature range is a temperature control adjustment range.
[0069] It should be noted that the deviation between each matched concentration is used to determine whether the matched temperature range is a temperature control adjustment range, specifically including: Based on the deviation between each matching concentration, determine the matching concentration whose deviation from other matching concentrations meets the requirements, and use it as the nearest matching concentration. Using the nearest matching concentration, determine whether the matching temperature range is a temperature control adjustment range.
[0070] It should be noted that the nearest matching concentration is a matching concentration whose deviation from other matching concentrations is less than 0.1 g / L.
[0071] In another embodiment, the nearest matching concentration is a matching concentration with a deviation rate of less than 1% from other matching concentrations, wherein the deviation rate is determined based on the ratio of the absolute value of the deviation between the matching concentration and other matching concentrations to the matching concentration.
[0072] Deviation meets requirements: The deviation between two matched concentrations is less than a preset threshold, such as less than 0.1 g / L (when expressed as mass concentration), or the deviation rate is less than 1% (when expressed as a relative proportion).
[0073] Nearest matching concentration: Within a matching temperature range, if a matching concentration meets the requirements in terms of deviation from multiple (or at least one) other matching concentrations within the range, then that concentration is called the nearest matching concentration. It represents the concentration value that is very close to other feasible concentration points at that temperature.
[0074] This is from the perspective of a single concentration point, determining whether it belongs to a certain "concentration cluster". If there are other concentration points very close to a concentration point, it means that at that temperature, even if the concentration fluctuates slightly, it will fall on another acceptable point, which suggests that the region is not sensitive to concentration changes.
[0075] The preset deviation threshold is 0.1 g / L (assuming the concentration unit is g / L, and 1.5% corresponds to 15 g / L, 2.0% corresponds to 20 g / L). For the T1 interval, the two matching concentrations, 15 g / L and 20 g / L, have a deviation of 5 g / L, which is greater than 0.1 g / L. Therefore, neither of them meets the condition of "the deviation from other matching concentrations meets the requirement," meaning there are no adjacent matching concentrations within the T1 interval. Now, assume another temperature interval, T4 = [850, 851)℃, with matching concentrations of 15.0 g / L, 15.1 g / L, and 15.2 g / L. The deviation of 0.1 g / L between 15.1 g / L and 15.0 g / L is equal to the threshold (which can be considered as meeting the requirement), and the deviation of 0.1 g / L between 15.1 g / L and 15.2 g / L is also equal to the threshold. Therefore, 15.1 g / L is an adjacent matching concentration. Similarly, the deviation of 0.1 g / L between 15.0 g / L and 15.1 g / L meets the requirement, therefore 15.0 g / L is also a near-matching concentration.
[0076] It is understood that when the number of adjacent matching concentrations within the matching temperature range meets the requirements, in one possible embodiment, when the number of adjacent matching concentrations within the matching temperature range is not less than 3, the matching temperature range is determined to be a temperature control adjustment range.
[0077] Temperature control adjustment range: This refers to the matching temperature range that is ultimately determined to require fine-tuned temperature control. The criterion for this is that within this temperature range, the number of adjacent matching concentrations meets a preset requirement, such as no fewer than three.
[0078] If multiple feasible concentration points are close to each other within a temperature range, it indicates that the concentration has a certain "adjustable range" at that temperature. This region is the "golden area" for process optimization, and it is worthwhile to conduct precise temperature control during production to ensure that the concentration remains stable within this wide concentration window. Conversely, if there are only isolated concentration points, the requirements for temperature control precision are extremely high, which is detrimental to production.
[0079] The preset requirement is for at least three adjacent matching concentrations. Considering temperature range T4 = [850, 851)℃, there are three matching concentrations: 15.0 g / L, 15.1 g / L, and 15.2 g / L. Calculations show that the deviation between these three concentrations does not exceed 0.1 g / L, therefore they are all adjacent matching concentrations, and the quantity of three meets the requirement. Thus, T4 is determined as the temperature control adjustment range. In contrast, within the T1 range, there are only two matching concentrations with a large deviation, and no adjacent matching concentrations exist, resulting in a quantity of zero, which does not meet the requirement. Therefore, T1 is not a temperature control adjustment range.
[0080] In another embodiment, the method for determining the temperature control adjustment range within the matching temperature range is as follows: Based on the overlap of the matching temperature ranges corresponding to the available doping concentrations, the available doping concentrations in the matching temperature ranges are determined and used as the matching concentrations. Based on the deviations between the matching concentrations, the deviation between each matching concentration is determined. Based on the deviation between each matching concentration, determine the matching concentration whose deviation from other matching concentrations meets the requirements, and use it as the neighboring matching concentration. Then, group the matching concentrations that are neighboring matching concentrations into the same group. By using the matching concentration data from each combination, it is determined whether the matching temperature range is a temperature control adjustment range.
[0081] It is understandable that when there is a combination of matching concentrations that meets the requirements, that is, when there is a combination of matching concentrations that is greater than the preset concentration threshold, the matching temperature range is determined to be the temperature control adjustment range.
[0082] S3 uses the consistency of the voltage drop data between the temperature control adjustment range data and the available doping concentration corresponding to the temperature control adjustment range to determine the adjustment scheme for the doping concentration in the temperature control adjustment range.
[0083] Furthermore, the method for determining the doping concentration adjustment scheme within the temperature control adjustment range is as follows: Within the identified temperature control range, a differentiated doping concentration adjustment scheme is developed to optimize the efficiency and effectiveness of process control.
[0084] First, within each temperature control adjustment range, matching combinations are identified based on the proximity of matching concentrations and the similarity of voltage decay behavior. Then, the similarity of these combinations is compared across ranges to identify common combinations. Next, based on the total number of temperature control adjustment ranges and the distribution of common combinations within each range, a specific adjustment scheme is determined. If the number of ranges is small or the coverage of common combinations is high, a refined preset scheme is applied uniformly to all ranges. If the number of ranges is large and the coverage of common combinations is low, a preset scheme is applied to common combinations, while a more coarse second preset scheme is applied to other combinations, thereby achieving efficient resource allocation.
[0085] Based on the temperature control adjustment range data, determine the number of temperature control adjustment ranges, use the available doping concentration corresponding to the temperature control adjustment range as the matching concentration, use the deviation between each matching concentration to determine the matching concentration whose deviation from other matching concentrations meets the requirements, and use it as the adjacent matching concentration, and divide the matching concentrations that are adjacent to each other into the same group. The number of temperature control adjustment ranges is the first key parameter for subsequent decisions. The number directly affects the complexity and workload of the overall adjustment process and forms the basis for determining whether differentiated processing is needed.
[0086] This provides a quantitative basis for subsequent judgment on whether a unified scheme can be adopted for all intervals.
[0087] Assuming that after preliminary screening, three temperature control adjustment ranges were identified: T1=[850,851)℃, T2=[855,856)℃, and T3=[860,861)℃, then the total number is 3.
[0088] Matching concentration: refers to the usable doping concentration value that can produce qualified materials within a certain temperature control range.
[0089] Deviation meets requirements: The absolute difference between two matched concentrations is less than a preset threshold (e.g., 0.1 g / L).
[0090] Nearby matching concentrations: Within a temperature control range, if the deviation of a matching concentration from at least one other matching concentration meets the requirements, these concentrations are considered to be near-matching concentrations.
[0091] Combination: Multiple concentration points that are adjacent to each other are grouped into a set, which is called a combination. The concentration points within a combination are very close in value, forming a concentration cluster.
[0092] Within a temperature range, multiple doping concentrations may exist, but not all concentrations are close to each other. By using a deviation threshold, clusters of concentrations that are clustered together can be identified. These clusters have high numerical similarity in concentration and may correspond to similar physicochemical properties.
[0093] Cluster analysis of concentrations within each temperature range was implemented, grouping discrete concentration points into combinations with internal consistency, laying the foundation for subsequent analysis of the similarity of performance within the combinations.
[0094] For T1 = [850, 851)℃, assume the matching concentrations are: 15.0, 15.1, 15.2, 16.0, 16.1 (unit: g / L). Set the deviation threshold to 0.1 g / L. Then, the deviations between 15.0, 15.1, and 15.2 are all ≤ 0.1, forming one combination A; the deviations between 16.0 and 16.1 are 0.1, forming another combination B. The deviation between 15.0 and 16.0 is 1.0 > 0.1, therefore they do not belong to the same combination.
[0095] Based on the consistency of voltage drop data among the matched concentrations in the combination, the similarity of voltage drop among the matched concentrations in the combination within different cycle number intervals is determined, and based on the similarity, a matching combination in the combination is determined; Consistency of voltage drop data: refers to the degree to which the voltage drop of batteries prepared with different matching concentrations within the same combination is similar within the same cycle number range.
[0096] Similarity of voltage drop: If the maximum difference between the voltage drop of all concentration points in the combination is less than the preset similarity threshold (e.g., 0.003V) within each cycle interval under consideration, then these concentration points are considered to be similar in voltage decay behavior.
[0097] Matching combination: A combination is upgraded to a matching combination if the voltage drop at all concentration points within it exhibits similar characteristics across different cycle counts. It represents a set of usable concentrations that not only have similar concentration values but also highly consistent electrochemical aging behavior within a certain temperature range.
[0098] Concentration points with similar numerical values (i.e., the same combination) may exhibit different long-term performance due to differences in microstructure. Therefore, further verification using electrochemical performance data is needed to confirm their true equivalence. Only concentration points with consistent performance throughout their entire lifecycle can be considered interchangeable process parameters.
[0099] By combining the proximity of concentration values with the consistency of electrochemical performance, a true "equivalent concentration window" was screened out, providing a reliable parameter range for subsequent process adjustments.
[0100] For combination A (15.0, 15.1, 15.2) under T1, the voltage drop per 100 cycles was tested in the range of 0-2000 cycles. It was found that the maximum difference in voltage drop at the three concentration points was less than 0.003V in all cycle intervals, therefore combination A was determined to be a matched combination.
[0101] Based on the similarity between the matching concentration of the matching combination of the temperature control adjustment range and other temperature control adjustment ranges, a general combination in the matching combination is determined. Based on the number of temperature control adjustment ranges and the general combination data in the temperature control adjustment range, an adjustment scheme for the doping concentration in the temperature control adjustment range is determined.
[0102] Similarity (across intervals): This refers to two matched combinations under two different temperature control intervals, whose concentration ranges or representative concentrations exhibit similar voltage drop behavior across different cycle number intervals. If the voltage drop curves of the two combinations essentially overlap (with a difference less than a preset threshold) in all cycle stages, then the two matched combinations are considered similar.
[0103] Universal Combination: A combination of materials that performs well across multiple temperature ranges is called a universal combination. It represents a concentration range where similar performance can be achieved at different temperatures, exhibiting cross-temperature universality.
[0104] Available concentrations at different temperature ranges may exhibit similar performance, meaning these temperature-concentration combinations are equivalent. Identifying this equivalence allows for "one adjustment for multiple uses" in subsequent process tweaks, simplifying control strategies.
[0105] Comparing the matching combination A (15.0-15.2) under T1, all of them belong to matching combination A under T2. A is a universal combination.
[0106] It should be noted that when the number of temperature control adjustment ranges meets the requirements, that is, when the number of temperature control adjustment ranges is relatively small, even if the doping concentration is adjusted according to the preset scheme in different temperature control adjustment ranges, the overall adjustment efficiency will not decrease. Therefore, the doping concentration is adjusted according to the preset scheme in different temperature control adjustment ranges.
[0107] The number of temperature control adjustment ranges meets the requirements: this means that the number is less than or equal to a preset threshold (e.g., 5). If the number is small, it means that there are not many temperature points that need to be adjusted. Even if each range is processed with a refined preset scheme, the overall workload is acceptable and will not lead to a decrease in efficiency.
[0108] The preset quantity threshold is 5. If the number of temperature control adjustment intervals is 3 (≤5), the quantity is deemed to meet the requirement, and the process proceeds directly to the "all intervals use the preset scheme" path. If the quantity is 8 (>5), the quantity does not meet the requirement, and the process proceeds to the next step.
[0109] Furthermore, when the number of temperature control adjustment intervals does not meet the requirements, if the number of general combinations within the temperature control adjustment intervals meets the requirements, i.e., is not less than the preset number of general combinations, then the doping concentration is adjusted according to the preset scheme within the temperature control adjustment intervals. In other cases, the doping concentration is adjusted using the preset scheme within the temperature control adjustment intervals of the general combinations. If the combination is not a general combination, the doping concentration is adjusted using the second preset scheme within the temperature control adjustment intervals.
[0110] The number of universal combinations meets the requirement: the total number of matching combinations identified as universal combinations in all temperature control and adjustment ranges is greater than or equal to a preset threshold for the number of universal combinations (e.g., 2). If the number of universal combinations is large, it indicates that the key concentration windows in most temperature ranges are universal, and in this case, applying the preset scheme uniformly to all ranges can still ensure high efficiency.
[0111] When there are many temperature ranges, if the key concentration windows (i.e., common combinations) in most ranges are similar, then adopting a uniform and refined approach can simultaneously optimize these universal windows, resulting in significant benefits.
[0112] Given a large number of cases, the decision on whether to continue using a unified and refined approach will be further based on the richness of the general combinations.
[0113] The preset threshold for the number of universal combinations is 2. There are currently 8 temperature control adjustment ranges, of which 5 have universal combinations. Since 5 ≥ 2, the requirement is met, and all ranges continue to use the preset scheme. If there is only 1 universal combination, the requirement is not met, and the next step is differentiated processing, resulting in many temperature ranges but few universality windows. At this point, fine-tuning all ranges would be inefficient; using coarse-grained processing would sacrifice opportunities to optimize the universality window. Therefore, a compromise strategy is adopted: fine-tuning (the preset scheme) is applied to the ranges containing universally valuable combinations, while a coarser second preset scheme is used for other ranges, thus achieving a balance between efficiency and effectiveness.
[0114] Specifically, the doping concentration is adjusted using a preset scheme, which includes: Based on the matching concentration in the matching combination, a concentration adjustment range is constructed. Within the concentration adjustment range, the voltage drop rate at different doping concentrations is determined according to a preset step size. Specifically, it is determined based on the voltage drop of the lithium battery constructed from the cathode material at a preset number of cycles. As long as the number of doping concentrations that meet the requirements for voltage drop in the matching combination is met, there is no need to adjust the doping concentration in other temperature control adjustment ranges. That is, the temperature control adjustment range and the doping concentration that meets the requirements for voltage drop are used as control indicators for the preparation process.
[0115] In one possible embodiment, the preset step size is 0.1 g / L. When the voltage decay is 0.002 V every 100 cycles, it is determined that the voltage drop at the doping concentration meets the requirement. If the number of doping concentrations that meet the voltage drop requirement is more than 4, it is determined that the number of doping concentrations that meet the voltage drop requirement in the matching combination meets the requirement.
[0116] Specifically, the second preset scheme is used to adjust the doping concentration, which includes: Based on the matching concentration in the matching combination, a concentration adjustment range is constructed. In the concentration adjustment range, the voltage drop rate at different doping concentrations is determined according to the second preset step size. Specifically, it is determined based on the voltage drop of the lithium battery constructed from the cathode material under a preset number of cycles. If the number of matching combinations in which the voltage drop in the temperature adjustment control range meets the requirements is not less than 2, then the temperature adjustment control range is taken as the target control range. The target control range and the doping concentration in which the voltage drop meets the requirements are used as control indicators for preparation processing.
[0117] It should be noted that the second preset step size is 0.2 g / L.
[0118] Example 2 In a second aspect, the present invention provides a computer device, comprising: a memory and a processor connected in communication, and a computer program stored in the memory and capable of running on the processor, wherein the processor executes the above-described method for preparing a lithium-rich manganese-based cathode material when running the computer program.
[0119] Furthermore, the method for determining the doping concentration adjustment scheme within the temperature control adjustment range is as follows: Based on the temperature control adjustment range data, determine the number of temperature control adjustment ranges, use the available doping concentration corresponding to the temperature control adjustment range as the matching concentration, use the deviation between each matching concentration to determine the matching concentration whose deviation from other matching concentrations meets the requirements, and use it as the adjacent matching concentration, and divide the matching concentrations that are adjacent to each other into the same group. Based on the consistency of voltage drop data among the matched concentrations in the combination, the similarity of voltage drop among the matched concentrations in the combination within different cycle number intervals is determined, and based on the similarity, a matching combination in the combination is determined; Based on the number of temperature control adjustment intervals, the matching combination of the temperature control adjustment intervals, and the similarity between the matching concentration of the matching combination and other temperature control adjustment intervals, an adjustment scheme for the doping concentration in the temperature control adjustment intervals is determined.
[0120] Furthermore, the matching combination is a combination in which the voltage drop between the matching concentrations is similar across different cycle number ranges. Specifically, when the deviation of the voltage drop between the matching concentrations in the combination across different cycle number ranges is less than 0.003V, the combination is determined to be a matching combination.
[0121] Furthermore, the similarity between the matching concentration of the matching combination and other temperature control adjustment ranges is determined based on the number of other temperature control adjustment ranges in which the matching concentration belongs to the matching concentration.
[0122] Furthermore, when the number of temperature control adjustment intervals meets the requirements, that is, when the number of temperature control adjustment intervals is relatively small, even if the doping concentration is adjusted according to the preset scheme in different temperature control adjustment intervals, the overall adjustment efficiency will not decrease. Therefore, the doping concentration is adjusted according to the preset scheme in different temperature control adjustment intervals.
[0123] In one possible embodiment, if the number of temperature control adjustment intervals is less than 3, then the number of temperature control adjustment intervals is determined to meet the requirement.
[0124] Additionally, it is understood that even if the number of temperature control adjustment intervals does not meet the requirements, it is still necessary to determine whether the number of matching combinations within each temperature control adjustment interval meets the requirements. It is understood that when the total number of matching combinations within different temperature control adjustment intervals meets the requirements, i.e., less than 10, then even if the doping concentration is adjusted according to the preset scheme in different temperature control adjustment intervals, the overall adjustment efficiency will not decrease. Therefore, the doping concentration is adjusted according to the preset scheme in different temperature control adjustment intervals.
[0125] Furthermore, it should be noted that when the total number of matching combinations within different temperature control adjustment ranges does not meet the requirements, the number of matching combinations within the temperature control adjustment range is obtained. When the number of matching combinations within the temperature control adjustment range meets the requirements, or when there is a matching combination with a matching concentration that meets the requirements (i.e., the number of matching combinations within the temperature control adjustment range is greater than 2, or there is a matching combination with a matching concentration of not less than 4), the voltage drop data between the doping concentrations within the temperature control adjustment range is relatively consistent, and the temperature control adjustment range matches the actual control requirements relatively well. Therefore, a preset scheme is used to adjust the doping concentration within the temperature control adjustment range.
[0126] Specifically, when the number of matching combinations within the temperature control adjustment range does not meet the requirements or there are no matching combinations with the required number of matching concentrations, the matching concentration of the matching combination within the temperature control range is determined to be similar to that of other temperature control ranges. Specifically, if the matching concentration of the matching combination exists in other temperature control ranges, it means that if the matching concentration of the matching combination within the temperature control adjustment range meets the control requirements for voltage drop, then once there is an abnormality in temperature control, it will also be a matching temperature in other temperature control adjustment ranges, thereby enabling effective control of the overall production quality of the cathode material. Therefore, based on this, a preset scheme is used to adjust the doping concentration within the temperature control adjustment range.
[0127] Additionally, it can be understood that if the matching concentration in the matching combination within the temperature control adjustment range does not exist in other temperature control ranges, then a general combination is determined based on the matching concentration in each matching combination belonging to other temperature control ranges. In this general combination, a preset scheme is used to adjust the doping concentration within the temperature control adjustment range. If it does not belong to a general combination, then a second preset scheme is used to adjust the doping concentration within the temperature control adjustment range.
[0128] It should be noted that the general combination is a matching combination that also belongs to the matching combination in other temperature control ranges.
[0129] Example 3 Thirdly, the present invention provides a lithium battery, wherein the positive electrode material of the lithium battery is prepared by the above-mentioned method for preparing a lithium-rich manganese-based positive electrode material.
[0130] The various embodiments in this specification are described in a progressive manner. Similar or identical parts between embodiments can be referred to mutually. Each embodiment focuses on describing the differences from other embodiments. In particular, the embodiments of apparatus, devices, and non-volatile computer storage media are basically similar to the method embodiments, so the descriptions are relatively simple; relevant parts can be referred to the descriptions of the method embodiments.
[0131] The foregoing has described specific embodiments of this specification. Other embodiments are within the scope of the appended claims. In some cases, the actions or steps recited in the claims may be performed in a different order than that shown in the embodiments and may still achieve the desired result. Furthermore, the processes depicted in the drawings do not necessarily require the specific or sequential order shown to achieve the desired result. In some embodiments, multitasking and parallel processing are possible or may be advantageous.
[0132] The above description is merely one or more embodiments of this specification and is not intended to limit this specification. Various modifications and variations can be made to the one or more embodiments of this specification by those skilled in the art. Any modifications, equivalent substitutions, improvements, etc., made within the spirit and principle of one or more embodiments of this specification should be included within the scope of the claims of this specification.
Claims
1. A method for preparing and processing a lithium-rich manganese-based cathode material, characterized in that, Specifically, it includes: Based on the preparation and processing data of lithium-rich manganese-based cathode materials, the consistency of voltage drop data in various calcination temperature ranges is determined. Based on the consistency, the matching temperature range of the calcination temperature range is determined. Based on the doping concentration data corresponding to different matching temperature ranges and the variation of voltage drop data under different doping concentrations, the usable doping concentration in the doping concentration is determined. Based on the deviation between the available doping concentrations, and using the matching temperature range data corresponding to the available doping concentrations as a basis, the temperature control adjustment range in the matching temperature range is determined. By utilizing the consistency of the voltage drop data between the temperature control adjustment range data and the available doping concentrations corresponding to the temperature control adjustment range, an adjustment scheme for the doping concentration in the temperature control adjustment range is determined.
2. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The calcination temperature range is determined based on the temperature control range of the lithium-rich manganese-based cathode material during the calcination stage.
3. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The consistency of the voltage drop data is determined based on the consistency of the voltage drop in different cycle ranges during the use of the lithium battery constructed with the lithium-rich manganese-based cathode material.
4. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The method for determining the matching temperature range of the calcination temperature range is as follows: Based on the consistency within the calcination temperature range, determine the consistency of voltage drop in lithium batteries constructed with lithium-rich manganese-based cathode materials within the calcination temperature range during use across different cycle number ranges. Using the aforementioned consistency, the deviation of the voltage drop within different cycle number intervals is determined; Based on the deviation, it is determined whether the calcination temperature range is a matching temperature range.
5. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 4, characterized in that, The deviation is determined based on the maximum value of the voltage deviation between the specified cycle number range for lithium batteries constructed with different lithium-rich manganese-based cathode materials.
6. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The method for determining the available doping concentration in the doping concentration is as follows: Based on the doping concentration data corresponding to different matching temperature ranges, the matching temperature range corresponding to the doping concentration is determined and used as the matching range of the doping concentration. Based on the variation of voltage drop data between each matching interval, the similarity of voltage drop in different cycle number intervals between each matching interval is determined. By utilizing the similarity of voltage drop across different cycle number ranges in each matching interval, it is determined whether the doping concentration is a usable doping concentration.
7. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 6, characterized in that, The matching interval is the matching temperature interval for the doping concentration that belongs to the matching temperature interval.
8. The method for preparing and processing lithium-rich manganese-based cathode material as described in claim 1, characterized in that, The method for determining the doping concentration adjustment scheme within the temperature control adjustment range is as follows: Based on the temperature control adjustment range data, determine the number of temperature control adjustment ranges, use the available doping concentration corresponding to the temperature control adjustment range as the matching concentration, use the deviation between each matching concentration to determine the matching concentration whose deviation from other matching concentrations meets the requirements, and use it as the adjacent matching concentration, and divide the matching concentrations that are adjacent to each other into the same group. Based on the consistency of voltage drop data among the matched concentrations in the combination, the similarity of voltage drop among the matched concentrations in the combination within different cycle number intervals is determined, and based on the similarity, a matching combination in the combination is determined; Based on the number of temperature control adjustment intervals, the matching combination of the temperature control adjustment intervals, and the similarity between the matching concentration of the matching combination and other temperature control adjustment intervals, an adjustment scheme for the doping concentration in the temperature control adjustment intervals is determined.
9. A computer device, comprising: A memory and processor connected in communication, and a computer program stored in the memory and capable of running on the processor, characterized in that, when the processor runs the computer program, it executes a method for preparing a lithium-rich manganese-based cathode material according to any one of claims 1-7.
10. A lithium battery, characterized in that, The positive electrode material of the lithium battery is prepared using the method for preparing a lithium-rich manganese-based positive electrode material as described in any one of claims 1-7.