Liquid injection amount evaluation method, liquid injection system, evaluation device, electronic device, and storage medium
Patent Information
- Application Number
- CN202610579088.X
- Authority / Receiving Office
- CN · China
- Patent Type
- Applications(China)
- Current Assignee / Owner
- Filing Date
- 2026-04-29
- Publication Date
- 2026-09-11
AI Technical Summary
当前，生产端注液量通常基于最大注液量进行经验折减或直接沿用设计值，然而，实际生产工艺中注液设备的注液速度、真空度、保压时间等工艺参数决定了电解液能否在有限时间内充分浸润，直接采用最大注液量往往会导致注液后电解液外溢，密封钉焊接污染，增加清洗成本，造成电解液浪费
本申请的技术方案对新电池体系仅需输入其最大注液量mmax和拟采用的工艺参数（v、P1、P2、t），即可直接输出实际注液量mact，可适应不同工艺条件下的注液需求，避免了固定经验值导致的浸润不充分或溢液风险，且无需进行大量梯度实验或破坏性测试，大幅缩短新产品导入周期，降低研发和试制成本。最大注液量mmax中V孔隙的计算采用烘干后极片和隔膜实际测试出的孔隙率，计算结果更接近真实值，为后续修正提供了准确基准。本专利方法确定的注液量恰好位于“浸润充分且不溢液”的临界点，避免了电解液外溢、密封钉焊接污染和清洗成本增加，同时减少了电解液浪费。
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Abstract
Description
Technical Field
[0001] This invention relates to the field of battery technology, and in particular to a method for evaluating the amount of electrolyte injected, an electrolyte injection system, an evaluation device, an electronic device, and a storage medium. Background Technology
[0002] Lithium-ion battery electrolyte, as a key carrier of ion transport in the battery, is composed of organic solvents, lithium salts, and additives. It conducts ions between the positive and negative electrodes of the lithium battery, ensuring its superior performance. The amount of electrolyte used plays a decisive role in battery reliability. The optimal amount of electrolyte injected into a lithium-ion battery to meet performance requirements without waste or adverse effects has been a subject of ongoing discussion. Currently, the electrolyte injection volume in production is usually based on empirical reduction of the maximum injection volume or directly adopted from the design value. However, in actual production processes, process parameters such as injection speed, vacuum level, and holding time determine whether the electrolyte can fully impregnate the battery within a limited time. Directly using the maximum injection volume often leads to electrolyte overflow after injection, contamination of the sealing nail welding, increased cleaning costs, and electrolyte waste. Summary of the Invention
[0003] The purpose of this invention is to overcome the shortcomings and defects of the prior art and to provide a method for evaluating the injection volume, an injection system, an evaluation device, an electronic device, and a storage medium.
[0004] To achieve the above objectives, this application adopts the following solution: A method for evaluating injection volume, which uses the injection efficiency coefficient η to evaluate the theoretical maximum injection volume m. max After correction, we obtain m; act =m max ·f(η) ;m act Actual injection volume, m max Theoretical maximum injection volume m max f(η) is a correction function; where the injection efficiency coefficient η is related to the injection rate v, the injection vacuum degree P1, the positive pressure P2, and the injection time t.
[0005] η = k1·P1 / P0 + k2·P2 / P0 + k3·v / v0 + k4·t / t0; where η is the injection efficiency coefficient, P0 is the standard atmospheric pressure, v0 is the baseline injection rate, t0 is the baseline injection time, v is the injection rate, P1 is the injection vacuum degree, P2 is the positive pressure, and t is the injection time; k1, k2, k3, and k4 are weighting coefficients, obtained by fitting historical production data.
[0006] Maximum injection volume m max =(V 空余 +V 孔隙 )×ρ 电解液 V空余 =V 壳内 -V 正极 -V 负极 -V 隔膜 -V 结构件 V 孔隙 =V 正极孔隙 +V 负极孔隙 +V 隔膜孔隙 Among them, V 正极孔隙 =V 正极 × Measured porosity of the positive electrode sheet after drying; V 负极孔隙 =V 负极 × Measured porosity of the negative electrode sheet after drying; V 隔膜孔隙 =V 隔膜 × Measured porosity of the diaphragm after drying.
[0007] The measured porosity of the dried positive electrode, the measured porosity of the dried negative electrode, and the measured porosity of the dried separator were independently determined by a true density meter using the gas displacement method.
[0008] Specifically, the following steps are included: Step S1: Calculate the maximum injection volume m max Step S2: Establish a correlation model between process parameters injection rate v, injection vacuum degree P1, positive pressure P2, injection time t, and injection efficiency coefficient η; Step S3: Determine the actual injection volume m in the injection process. act .
[0009] f(η) = a·η + b; a and b are correction coefficients, which are obtained by collecting actual liquid injection volume data of batteries with different capacities under different process parameters and calculating the maximum liquid injection volume.
[0010] The present invention also includes an electrolyte injection system, comprising: an electrolyte injection pump for injecting electrolyte into the battery based on the electrolyte injection volume obtained by the evaluation method.
[0011] The present invention also includes an evaluation apparatus, the apparatus comprising: The acquisition module is used to acquire the injection rate v, injection vacuum P1, positive pressure P2, and injection time t, respectively. The determining module is used to determine the injection volume of the injection pump based on the values obtained by the acquiring module.
[0012] The present invention also includes an electronic device comprising: a processor and a memory storing computer program instructions; wherein the processor executes the computer program instructions to implement the injection volume assessment method.
[0013] The present invention also includes a storage medium storing computer program instructions, which, when executed by a processor, implement the injection volume assessment method.
[0014] Compared with the prior art, the beneficial effects of the present invention are as follows: The technical solution of this application only requires inputting the maximum electrolyte injection volume m for the new battery system. max Given the proposed process parameters (v, P1, P2, t), the actual injection volume m can be directly output. act It can adapt to the injection requirements under different process conditions, avoiding the risks of insufficient wetting or overflow caused by fixed experience values, and eliminates the need for extensive gradient experiments or destructive testing, significantly shortening the new product introduction cycle and reducing R&D and trial production costs. Maximum injection volume m max The porosity of the medium-sized V-shaped electrode is calculated using the porosity actually measured by the dried electrode and diaphragm. The calculated result is closer to the true value, providing an accurate benchmark for subsequent corrections. The injection volume determined by this patented method is precisely at the critical point of "sufficient wetting without overflow," avoiding electrolyte overflow, sealing nail welding contamination, and increased cleaning costs, while also reducing electrolyte waste. Attached Figure Description
[0015] Figure 1 This is a diagram illustrating the injection volume gradient verification of an embodiment of the present invention; Figure 2 This is a disassembly diagram of the interface of an embodiment of the present invention; Figure 3 This is a diagram showing the disassembly results of an embodiment of the present invention. Detailed Implementation
[0016] The present invention will be further described in detail below with reference to the accompanying drawings and specific embodiments. It should be understood that the specific embodiments described herein are merely illustrative of the invention and are not intended to limit the invention.
[0017] Example 1: Taking a square aluminum-cased lithium-ion battery (design capacity 237Ah, positive electrode lithium iron phosphate, negative electrode graphite system) as an example, with a casing length of 30.4cm, casing thickness of 4.2cm, and casing height of 13.1cm, the actual liquid injection process liquid injection volume was evaluated.
[0018] A method for evaluating injection volume, which uses the injection efficiency coefficient η to evaluate the theoretical maximum injection volume m. max After correction, we obtain m; act =m max ·f(η) ;m act Actual injection volume, m max Theoretical maximum injection volume m max f(η) is a correction function; where the injection efficiency coefficient η is related to the injection rate v, the injection vacuum degree P1, the positive pressure P2, and the injection time t.
[0019] Specifically, the following steps are included: Step S1: Calculation of maximum injection volume; m max V 壳内 =1672.6cm 3 V 正极 =726.7cm 3 V 负极 =574.2cm 3 V 隔膜 =119.4cm 3 V 结构件 =32.9cm 3 V 空余 =1672.6-726.7-574.2-119.4-32.9=219.4cm 3 ; After drying, the porosity of the positive electrode sheet was 27.53%, the porosity of the negative electrode sheet was 27.87%, and the porosity of the separator was 53.68%. When calculating the pore volume, the volume of the positive and negative electrode foils is subtracted, resulting in V. 正极孔隙 =184.0cm 3 V 负极孔隙 =152.7cm 3 V 隔膜孔隙 =64.3cm 3 V 孔隙 =184.0 + 152.7 + 64.3 = 401cm 3 Electrolyte density ρ 电解液 It is 1.235 g / cm³ 3 ; Maximum injection volume m max =(V 空余 +V 孔隙 )×ρ 电解液 =(219.4+401)×1.235=766g; Step S2: Determine the process parameters and the injection efficiency coefficient η; Key process parameters (the optimal parameters to ensure sufficient wetting without overflow) for batteries with the same cathode (lithium iron phosphate, graphite anode) but different capacities as the 237Ah system were collected. These parameters included the injection rate v (mL / s), injection vacuum P1 (kPa), positive pressure P2 (kPa), and injection time t (min), as shown in Table 1. Here, P0 is the standard atmospheric pressure of 101.325 kPa, v0 is the baseline injection rate of 2 mL / s, and t0 is the baseline injection time of 20 min. max m is calculated in step 1. act This refers to the actual liquid injection volume required to ensure that batteries of different capacities are fully immersed under different liquid injection process parameters without overflow.
[0020] Table 1 314 1.5 90 570 20 1167.5 1132 200 2 80 400 13 700.3 650 60 2.3 60 400 5 243 215 324 1 90 600 20 1097.5 1040 130 2.1 80 400 7 496 450 Fitting the above 5 sets of data, and setting k1+k2+k3+k4=1, we get k1=0.3730, k2=0.0451, k3=0.3186 and k4=0.2633. The expression for the injection efficiency coefficient η is: η=0.3730·P1 / P0+0.0451·P2 / P0+0.3186·v / v0+0.2633·t / t0 Step S3: Determine the actual injection volume (m) for the injection process. act Table 1 shows the actual electrolyte injection volume data for batteries of different capacities under different process parameters, and calculates the corresponding maximum electrolyte injection volume. The fitted values are a=0.3314, b=0.6092, and the expression for f(η) is 2: f(η) = 0.3314·η + 0.6092 The optimal electrolyte injection process parameters for a 237Ah battery are: injection rate v = 1.8mL / s, injection vacuum P1 = 85kPa, positive pressure P2 = 570kPa, and injection time t = 20min. Substituting these parameters into expression 1, we can obtain η. η=0.3730·85 / 101.325+0.0451·570 / 101.325+0.3186·1.8 / 2+0.2633·20 / 20=1.1166 Substituting η into expression 2, we obtain f(η); f(η)=0.3314·1.1166+0.6092=0.979 Based on the actual injection process, the injection volume evaluation model m act =m max ·f(η), to obtain m act =766·0.979≈750g; Model Validation: Sixteen batteries were used for gradient validation of electrolyte injection volume. Validation was conducted with injection volumes of 750g, 755g, 760g, and 765g under the same process parameters. The results are as follows: Figure 1 As shown. With a 750g electrolyte filling volume, there was no electrolyte residue in the filling hole, and nailing did not damage the electrolyte; with a 755g electrolyte filling volume, there was no electrolyte residue in the filling hole, but nailing resulted in a loss of 1.175g of electrolyte; with a 760g electrolyte filling volume, there was no electrolyte residue in the filling hole, but nailing resulted in a loss of 3.525g of electrolyte; with a 765g electrolyte filling volume, there was electrolyte residue in the filling hole, and nailing resulted in a loss of 8.6g of electrolyte. The 750g electrolyte filling volume battery was disassembled, and the interface is shown below. Figures 2-3 As shown, the interface is good. Therefore, the actual injection volume of 750g obtained using the method of this patent is more suitable, as it not only ensures sufficient wetting but also prevents leakage.
[0022] The present invention also includes an electrolyte injection system, comprising: an electrolyte injection pump for injecting electrolyte into the battery based on the electrolyte injection volume obtained by the evaluation method.
[0023] The present invention also includes an evaluation apparatus, the apparatus comprising: The acquisition module is used to acquire the injection rate v, injection vacuum P1, positive pressure P2, and injection time t, respectively. The determining module is used to determine the injection volume of the injection pump based on the values obtained by the acquiring module.
[0024] The present invention also includes an electronic device comprising: a processor and a memory storing computer program instructions; wherein the processor executes the computer program instructions to implement the injection volume assessment method.
[0025] The present invention also includes a storage medium storing computer program instructions, which, when executed by a processor, implement the injection volume assessment method.
[0026] The foregoing has shown and described the basic principles, main features, and advantages of the present invention. It will be apparent to those skilled in the art that the present invention is not limited to the details of the above exemplary embodiments, and that the present invention can be implemented in other specific forms without departing from the spirit or basic features of the present invention. Therefore, the embodiments should be regarded as exemplary and non-limiting in all respects, and the scope of the invention is defined by the appended claims rather than the foregoing description. Thus, it is intended that all variations falling within the meaning and scope of the equivalents of the claims be included within the invention.
[0027] Furthermore, it should be understood that although this specification describes embodiments, not every embodiment contains only one independent technical solution. This narrative style is merely for clarity. Those skilled in the art should consider the specification as a whole, and 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 evaluating injection volume, characterized in that, The theoretical maximum injection amount m is corrected by the injection efficiency coefficient η max is obtained. m act =m max ·f(η) ;m act Actual injection volume, m max Theoretical maximum injection volume m max , f(η) is a correction function; wherein the injection efficiency coefficient η is associated with the injection rate v, the injection vacuum degree P1, the positive pressure P2, and the injection time t.
2. The method for evaluating the injection volume according to claim 1, characterized in that η = k1·P1 / P0 + k2·P2 / P0 + k3·v / v0 + k4·t / t0; wherein, η is the injection efficiency coefficient, P0 is the standard atmospheric pressure, v0 is the baseline injection rate, t0 is the baseline injection time, v is the injection rate, P1 is the injection vacuum degree, P2 is the positive pressure, and t is the injection time; k1, k2, k3, and k4 are weighting coefficients, which are obtained by fitting historical production data.
3. The method for evaluating injection volume according to claim 1, characterized in that the maximum injection volume m max =(V 空余 +V 孔隙 )×ρ 电解液 V 空余 =V 壳内 -V 正极 -V 负极 -V 隔膜 -V 结构件 V 孔隙 =V 正极孔隙 +V 负极孔隙 +V 隔膜孔隙 Among them, V 正极孔隙 =V 正极 ×Measured porosity of positive electrode sheet after drying; V 负极孔隙 =V 负极 ×Measured porosity of negative electrode sheet after drying; V 隔膜孔隙 =V 隔膜 ×Measured porosity of separator after drying.
4. The method for evaluating the amount of liquid injected according to claim 3, characterized in that the measured porosity of the dried positive electrode, the measured porosity of the dried negative electrode, and the measured porosity of the dried diaphragm are independently determined by a true density meter using the gas displacement method.
5. The method for evaluating injection volume according to claim 1, characterized in that it specifically includes the following steps: Step S1: Calculate the maximum injection volume m max Step S2: Establish a correlation model between process parameters injection rate v, injection vacuum degree P1, positive pressure P2, injection time t, and injection efficiency coefficient η; Step S3: Determine the actual injection volume m in the injection process. act .
6. The method for evaluating the injection volume according to claim 1, characterized in that f(η) = a·η + b; a and b are correction coefficients, obtained by collecting actual injection volume data of batteries with different capacities under different process parameters and calculating the maximum injection volume.
7. A liquid injection system, characterized in that, include: An injection pump is used to inject electrolyte into a battery based on the injection volume obtained by the evaluation method according to any one of claims 1-6.
8. An evaluation device, characterized in that, The device includes: The acquisition module is used to acquire the injection rate v, injection vacuum P1, positive pressure P2, and injection time t, respectively. The determining module is used to determine the injection volume of the injection pump based on the values obtained by the acquiring module.
9. An electronic device, characterized in that, The device includes: a processor and a memory storing computer program instructions; the processor, when executing the computer program instructions, implements the injection volume assessment method according to any one of claims 1-6.
10. A storage medium, characterized in that, The computer storage medium stores computer program instructions, which, when executed by a processor, implement the injection volume evaluation method according to any one of claims 1-6.