Intelligent rolling adjustment method

Abstract

The invention discloses an intelligent rolling adjustment method which comprises the following steps: establishing a rolling database, and converting parameters of a battery pole piece which is being produced into coefficient codes corresponding to the parameters of the pole piece; matching the coefficient code corresponding to the pole piece parameter with a rolling database, and outputting rolling data; the roller press is automatically adjusted according to the output rolling data, and then the pole piece is rolled; carrying out on-line thickness test and on-line elongation rate test on the rolled pole piece; if the thickness and the elongation both meet the requirements, the roller press continues to roll the pole piece; and if the thickness or the elongation rate does not meet the requirements, the roller press stops automatic rolling, the rolling data is manually adjusted until the thickness and the elongation rate meet the requirements, and the rolling database is corrected into the updated rolling data. According to the intelligent roller press, the problem that the roller press can intelligently adjust the rolling parameters for battery pole pieces of different material systems is solved.

Description

Technical Field

[0001] The present invention belongs to the technical field of power batteries, and in particular relates to an intelligent roller pressure regulating method. Background Art

[0002] With the requirements of electric equipment for lightweight and long battery life, the high energy density of batteries used as power is increasingly required, so the design of battery cells is more extreme. For example, more active materials are required in the shell of the same volume of battery cells, resulting in higher surface density and compaction of battery poles, which means that more slurry and active materials need to be coated per unit area. Not only that, during the rolling process of the pole pieces, more mass of active materials are required per unit volume. In order to achieve the above goals, the rolling process is particularly important. Different material systems correspond to different rolling equipment setting parameters. Even fluctuations in the physicochemical indicators of the materials will affect the adjustment of the rolling equipment parameters, and even approach the threshold of the equipment, affecting the uniformity of the distribution of the pole piece materials. Faced with battery pole pieces of different material systems, there is currently no adjustment method that can enable the roller press to quickly adapt to material switching. Summary of the invention

[0003] The present invention proposes an intelligent rolling adjustment method, which solves the problem that a rolling machine can intelligently adjust rolling parameters for battery pole pieces of different material systems.

[0004] The present invention provides an intelligent roller pressure adjustment method, comprising the following steps:

[0005] S1 establishes a roller pressing database;

[0006] S2 converts the battery pole piece parameters being produced into coefficient codes corresponding to the pole piece parameters;

[0007] S3 matches the coefficient code corresponding to the pole piece parameters with the rolling database and outputs the rolling data;

[0008] S4: the roller press automatically adjusts according to the rolling data outputted in step S3, and then rolls the pole piece;

[0009] S5 performs online thickness test and online elongation test on the pole piece after rolling;

[0010] If the thickness and elongation meet the requirements, the roller press continues to roll the pole piece;

[0011] If the thickness or elongation does not meet the requirements, the roller press will stop rolling automatically;

[0012] S6 When the thickness or elongation does not meet the requirements, the rolling data is manually adjusted until the thickness and elongation meet the requirements, and the rolling database is corrected to the updated rolling data.

[0013] Furthermore, step S1 establishes a rolling database; comprising:

[0014] S11 classifies the material systems of battery pole pieces and combines the codes of the positive and negative electrode material systems as the coefficient code of the pole piece material system;

[0015] S12 marks the particle size, compaction density, surface density, conductive agent mass percentage and binder mass percentage of the same material system according to a preset step size;

[0016] S13 summarizes the recommended values ​​of rolling data when the mass production pole piece performance index PPK>2;

[0017] S14 establishes a rolling database according to the mapping relationship between the pole piece coefficient code and the recommended rolling data value.

[0018] Furthermore, step S11 classifies the material system of the battery electrode, specifically:

[0019] The positive electrode material system includes lithium iron phosphate (code a1), ternary single crystal (code a2), ternary polycrystalline (code a3), lithium cobalt oxide (code a4), phosphoric acid (code a5), and lithium manganese iron (code a6).

[0020] The negative electrode material system includes graphite (code 1), silicon carbon (code 2), lithium titanate (code 3), and metallic lithium (code 4).

[0021] Furthermore, step S11 combines the codes of the positive and negative electrode material systems as the coefficient code of the electrode material system, specifically: the lithium iron phosphate-graphite material system code is a11, the ternary polycrystalline silicon carbon material system code is a32, and so on.

[0022] Furthermore, step S12 respectively identifies the particle size, compaction density, surface density, conductive agent mass percentage and binder mass percentage of the same material system according to a preset step length; specifically:

[0023] The particle size of the same material system is marked according to the particle size distribution L1 as a step interval, and the particle size coefficient code is recorded as b;

[0024] The compaction density of the same material system is marked according to the compaction density distribution L2 as a step interval, and the compaction coefficient code is recorded as c;

[0025] The surface density of the same material system is marked according to the surface density distribution L3 as a step interval, and the surface density coefficient code is recorded as d;

[0026] The mass percentage of the conductive agent of the same material system is marked according to the conductive agent mass percentage distribution L4 as a step interval, and the mass percentage code of the conductive agent is recorded as e;

[0027] The binder mass percentage of the same material system is marked according to the binder mass percentage distribution L5 as a step interval, and the binder mass percentage code is recorded as f.

[0028] Furthermore, the battery electrode parameters include material system, material particle size, compaction density, surface density, conductive agent mass percentage and adhesive mass percentage, and the corresponding coefficient codes are a, b, c, d, e, and f, respectively.

[0029] Furthermore, the roller pressure data includes speed, left roller gap, right roller gap, pressure, unwinding tension and winding tension.

[0030] Further, step S5 performs an online elongation test on the rolled pole piece; specifically:

[0031] S51 tests the spacing X before rolling and the spacing Y after rolling of a certain section of battery pole pieces

[0032] The spacing before rolling is X=X2-X1, where X1 is the starting value of the battery pole piece of this section before rolling, and X2 is the end value of the battery pole piece of this section before rolling;

[0033] The spacing after rolling is Y=Y2-Y1, where Y1 is the starting value of the battery pole piece of this section after rolling, and Y2 is the end value of the battery pole piece of this section after rolling;

[0034] S52 calculates the spacing correction value of the battery pole piece after rolling.

[0035] Y correction = (Y + Y') / 2

[0036] Among them, Y'=A° / 180°*πr, A° is the angle formed by the steel roller, and r is the radius of the steel roller;

[0037] S53 calculates the elongation rate of the battery pole piece

[0038] Elongation rate = (correction of the gap Y after rolling - gap X before rolling) / gap X before rolling.

[0039] Furthermore, in step S5, a laser thickness gauge is used to perform an online thickness test on the pole piece after rolling.

[0040] Furthermore, in step S12, L1 is 0.15 um, L2 is 0.1 g / cc, L3 is 20 g / m2, L4 is 0.3, and L5 is 0.2.

[0041] Compared with the prior art, the present invention has the following beneficial effects:

[0042] The present invention converts the parameters of the battery pole piece being produced into coefficient codes corresponding to the pole piece parameters by establishing a rolling database; matches the coefficient codes corresponding to the pole piece parameters with the rolling database, and outputs rolling data; the roller press automatically adjusts according to the output rolling data, and then rolls the pole piece. By performing online thickness testing and online elongation testing on the pole piece after rolling, the roller press can intelligently adjust the rolling parameters for battery pole pieces of different material systems. If both the thickness and elongation meet the requirements, the roller press continues to roll the pole piece; if the thickness or elongation does not meet the requirements, the roller press stops automatic rolling, and manually adjusts the rolling data until the thickness and elongation meet the requirements, and the rolling database is corrected to the updated rolling data. BRIEF DESCRIPTION OF THE DRAWINGS

[0043] In order to more clearly illustrate the technical solutions in the embodiments of the present invention, the drawings required for use in the embodiments will be briefly introduced below. Obviously, the drawings described below are only some embodiments of the present invention. For ordinary technicians in this field, other drawings can be obtained based on these drawings without paying creative work.

[0044] Figure 1 A flow chart of an intelligent roller pressure adjustment method provided by an embodiment of the present invention;

[0045] Figure 2 It is a schematic diagram of intelligently monitoring the elongation rate of a pole piece according to an embodiment of the present invention;

[0046] Figure 3 Schematic diagram of the steel roller angle according to an embodiment of the present invention. DETAILED DESCRIPTION

[0047] The following will be combined with the drawings in the embodiments of the present invention to clearly and completely describe the technical solutions in the embodiments of the present invention. Obviously, the described embodiments are only part of the embodiments of the present invention, not all of the embodiments. Based on the embodiments of the present invention, all other embodiments obtained by ordinary technicians in this field without creative work are within the scope of protection of the present invention.

[0048] See also Figure 1 The embodiment of the present invention provides an intelligent roller pressure adjustment method, comprising the following steps:

[0049] S1 Establishing roller pressing database

[0050] Roller Pressing Database

[0051]

[0052]

[0053]

[0054]

[0055]

[0056]

[0057]

[0058] The process of establishing a roller pressing database includes:

[0059] S11 distinguishes and classifies the material systems of battery electrodes, and combines the codes of the positive and negative electrode material systems as the coefficient code of the electrode material system.

[0060] The material systems of battery poles are classified into:

[0061] The positive electrode material system includes lithium iron phosphate (code a1), ternary single crystal (code a2), ternary polycrystalline (code a3), lithium cobalt oxide (code a4), phosphoric acid (code a5), and lithium manganese iron (code a6).

[0062] The negative electrode material system includes graphite (code 1), silicon carbon (code 2), lithium titanate (code 3), and metallic lithium (code 4).

[0063] The codes of the positive and negative electrode material systems are combined as the coefficient code of the electrode material system, specifically: the lithium iron phosphate-graphite material system code is a11, the ternary polycrystalline silicon carbon material system code is a32, and so on.

[0064] S12 marks the particle size, compaction density, surface density, conductive agent mass percentage and binder mass percentage of the same material system according to a preset step size.

[0065] Specifically:

[0066] The particle size of the same material system is marked according to the particle size distribution L1 as a step interval, and the particle size coefficient code is recorded as b; in this embodiment, L1 is 0.15um. For example, 0.85-1um is b1, 1-1.15um is b2, and 1.15-1.3 is b3.

[0067] The compaction density of the same material system is marked according to the compaction density distribution L2 as a step interval, and the compaction coefficient code is recorded as c; in this embodiment, L2 is 0.1 g / cc.

[0068] The surface density of the same material system is marked according to the surface density distribution L3 as a step interval, and the surface density coefficient code is recorded as d; in this embodiment, L3 is 20g / m2.

[0069] The mass percentage of the conductive agent in the same material system is marked according to the conductive agent mass percentage distribution L4 as a step interval, and the conductive agent mass percentage code is recorded as e; in this embodiment, L4 is 0.3.

[0070] The binder mass percentage of the same material system is marked according to the binder mass percentage distribution L5 as a step interval, and the binder mass percentage code is recorded as f. In this embodiment, L5 is 0.2.

[0071] It should be noted that, in this embodiment, L1 is 0.15um, L2 is 0.1g / cc, L3 is 20g / m2, L4 is 0.3, and L5 is 0.2. These values ​​are only for this embodiment, and in other embodiments, they may be different values.

[0072] S13 summarizes the recommended values ​​of rolling data when the mass production pole piece PPK>2. PPK stands for Performance Index, which means performance index.

[0073] S14 establishes a rolling database according to the mapping relationship between the pole piece coefficient code and the recommended rolling data value.

[0074] Roll pressure data include speed, left roll gap, right roll gap, pressure, unwinding tension and winding tension.

[0075] The mapping relationship between the pole piece coefficient code and the recommended rolling data value can be schematically represented as: {a, b, c, d, e, f} → {speed, left roller gap, right roller gap, pressure, unwinding tension, winding tension}. It should be noted that this schematic relationship is not the following mapping: a → speed, b → left roller gap, c → right roller gap, d → pressure, e → unwinding tension, f → winding tension, but input {a, b, c, d, e, f}, and the corresponding roller press outputs {speed, left roller gap, right roller gap, pressure, unwinding tension, winding tension} rolling data recommended values.

[0076] S2 converts the battery electrode parameters being produced into coefficient codes corresponding to the electrode parameters.

[0077] Battery electrode parameters include material system, material particle size, compaction density, surface density, conductive agent mass percentage and adhesive mass percentage, and the corresponding coefficient codes are a, b, c, d, e, and f respectively.

[0078] The lithium iron phosphate used in the positive electrode sheet currently being produced has a coefficient code of a1; the particle D50 (D50 indicates the particle size corresponding to 50% of the cumulative distribution in the particle size system) is 0.9um, and its coefficient code is b2; the compacted density is 2.55g / cc, and its coefficient code is c6; the surface density is 400g / m2, and its coefficient code is d5; the conductive agent is only carbon black with a mass percentage of 2, and its coefficient code is e3; the mass percentage of the binder is 1.8, and its coefficient code is f5. The coefficient codes corresponding to the above electrode parameters are {a1 b2 c6d5 e3 f5}.

[0079] S3 matches the coefficient code corresponding to the pole piece parameters with the rolling database and outputs the rolling data.

[0080] The coefficient codes {a1 b2 c6 d5 e3 f5} corresponding to the above-mentioned pole piece parameters are matched with the rolling database, and it is found that the corresponding rolling data recommendation values ​​have been saved in the rolling machine database. At this time, the rolling machine outputs the following rolling data values: left roller gap -50um, right roller gap -100um, unwinding tension 150N, winding tension 200N, rolling roller force 80t, and roller speed 100m / min.

[0081] S4 The roller press automatically adjusts according to the rolling data outputted in step S3, and then rolls the pole piece.

[0082] After the roller press is automatically adjusted, the pole piece will be automatically rolled within the next minute.

[0083] S5 performs online thickness test and online elongation test on the pole pieces after rolling.

[0084] If the thickness and elongation meet the requirements, the roller press continues to roll the pole piece;

[0085] If the thickness or elongation does not meet the requirements, the roller press will stop automatically rolling.

[0086] Use a laser thickness gauge to perform online thickness testing on the pole piece after rolling. The principle of laser thickness testing is to use a laser beam to pass through the surface of the object to be tested, and after reflection and refraction inside the object, it is received by the detector and the thickness of the object is determined by measuring the degree of laser beam divergence. At present, online thickness measurement technology is relatively mature and will not be described in detail here.

[0087] In the industry, the elongation rate is generally tested by stopping the machine for sampling. The present invention does not require stopping the machine and can be tested directly in the roller press. The spacing after rolling is corrected to make it closer to the actual value.

[0088] See also Figure 2 and Figure 3In the embodiment of the present invention, the electrode in the dressing area is tested for online elongation rate, and the specific operation method is as follows:

[0089] S51 tests the spacing X before rolling and the spacing Y after rolling of a certain section of battery pole pieces

[0090] The spacing before rolling is X=X2-X1, where X1 is the starting value of the battery pole piece of this section before rolling, and X2 is the end value of the battery pole piece of this section before rolling;

[0091] The spacing after rolling is Y=Y2-Y1, where Y1 is the starting value of the battery pole piece of this section after rolling, and Y2 is the end value of the battery pole piece of this section after rolling;

[0092] S52 calculates the spacing correction value of the battery pole piece after rolling.

[0093] Y correction = (Y + Y') / 2

[0094] Among them, Y'=A° / 180°*πr, A° is the angle formed by the steel roller, and r is the radius of the steel roller;

[0095] S53 calculates the elongation rate of the battery pole piece

[0096] Elongation rate = (correction of the gap Y after rolling - gap X before rolling) / gap X before rolling.

[0097] S6 When the thickness or elongation does not meet the requirements, the rolling data is manually adjusted until the thickness and elongation meet the requirements, and the rolling database is corrected to the updated rolling data.

[0098] In this embodiment, the pole piece design requires a thickness of 110±3um and an elongation of 0.4±0.3%. If both the thickness gauge and the elongation meet the requirements, the rolling process continues, and the rolling machine automatically records the data.

[0099] If the tested thickness is 125um, which does not meet 110±3um, the manual operation interface of the roller press is stopped, and the operation password is entered to switch from automatic mode to manual mode, the roller press pressure is adjusted from 80 tons to 90 tons, the roller press is manually turned on to roll the electrode for a distance, such as 6m, and the automatic thickness gauge data is refreshed to be within the design range of 110±3um. The new parameters of the roller press are manually saved, namely: left roller gap -50um, right roller gap -100um, unwinding tension 150N, winding tension 200N, rolling roller force 90t (originally 80t), roller speed 100m / min, and the database automatically saves the updated data. The next time the same electrode roller press will automatically output the newly adjusted parameters, and then the manual mode will be converted to automatic mode, and the roller press starts rolling. At this time, the roller press tests the thickness and elongation and records the test data online.

[0100] If the tested elongation is 1%um, which does not meet 0.4±0.3%, the manual operation interface of the roller press is stopped, and the operation password is entered to switch from automatic mode to manual mode. The left roller gap of the roller press is adjusted from -50um to -40um, the right roller gap is adjusted from -100um to -80um, and the roller press pressure is adjusted from 80 tons to 90 tons. The roller press is manually turned on to roll the electrode for a distance of 6m, for example, and the automatic thickness gauge data is refreshed to be within the design range of 110±3um. The elongation The rate is 0.4±0.3%, and the new parameters of the roller press are manually saved, namely: left roller gap -40um, right roller gap -80um, unwinding tension 150N, winding tension 200N, roller force 90t (originally 80t), roller speed 100m / min. The database automatically saves the updated data. The next time the same pole piece roller press will automatically output the newly adjusted parameters, and then the manual mode will be converted to automatic mode. The roller press starts rolling. At this time, the roller press tests the thickness and elongation and records the test data online.

[0101] The intelligent roller pressure adjustment method disclosed in the embodiment of the present invention is introduced in detail above. Specific examples are used in this article to illustrate the principle and implementation mode of the present invention. The description of the above embodiments is only used to help understand the core idea of ​​the present invention. At the same time, for those skilled in the art, according to the idea of ​​the present invention, there will be changes in the specific implementation mode and application scope. In summary, the content of this specification should not be understood as a limitation on the present invention.

Claims

1. An intelligent roller pressure adjustment method, characterized in that: The following steps are involved: S1 establishes a roller pressing database; S2 converts the battery pole piece parameters being produced into coefficient codes corresponding to the pole piece parameters; S3 matches the coefficient code corresponding to the pole piece parameters with the rolling database and outputs the rolling data; S4: the roller press automatically adjusts according to the rolling data outputted in step S3, and then rolls the pole piece; S5 performs online thickness test and online elongation test on the pole piece after rolling; If the thickness and elongation meet the requirements, the roller press continues to roll the pole piece; If the thickness or elongation does not meet the requirements, the roller press will stop rolling automatically; S6 When the thickness or elongation does not meet the requirements, the rolling data is manually adjusted until the thickness and elongation meet the requirements, and the rolling database is corrected to the updated rolling data.

2. The intelligent roller pressure adjustment method according to claim 1, characterized in that: Step S1: establishing a rolling database; including: S11 classifies the material systems of battery pole pieces and combines the codes of the positive and negative electrode material systems as the coefficient code of the pole piece material system; S12 marks the particle size, compaction density, surface density, conductive agent mass percentage and binder mass percentage of the same material system according to a preset step size; S13 summarizes the recommended values ​​of rolling data when the mass production pole piece performance index PPK>2; S14 establishes a rolling database according to the mapping relationship between the pole piece coefficient code and the recommended rolling data value.

3. The intelligent roller pressure adjustment method according to claim 2, characterized in that: Step S11 classifies the material system of the battery electrode, specifically: The positive electrode material system includes lithium iron phosphate (code a1), ternary single crystal (code a2), ternary polycrystalline (code a3), lithium cobalt oxide (code a4), phosphoric acid (code a5), and lithium manganese iron (code a6). The negative electrode material system includes graphite (code 1), silicon carbon (code 2), lithium titanate (code 3), and metallic lithium (code 4).

4. The intelligent roller pressure adjustment method according to claim 3, characterized in that: Step S11 combines the codes of the positive and negative electrode material systems as the coefficient code of the electrode material system, specifically including: the lithium iron phosphate-graphite material system code is a11, and the ternary polycrystalline silicon carbon material system code is a32.

5. The intelligent roller pressure adjustment method according to claim 2, characterized in that: Step S12 marks the particle size, compaction density, surface density, conductive agent mass percentage and binder mass percentage of the same material system according to a preset step length; specifically: The particle size of the same material system is marked according to the particle size distribution L1 as a step interval, and the particle size coefficient code is recorded as b; The compaction density of the same material system is marked according to the compaction density distribution L2 as a step interval, and the compaction coefficient code is recorded as c; The surface density of the same material system is marked according to the surface density distribution L3 as a step interval, and the surface density coefficient code is recorded as d; The mass percentage of the conductive agent of the same material system is marked according to the conductive agent mass percentage distribution L4 as a step interval, and the mass percentage code of the conductive agent is recorded as e; The binder mass percentage of the same material system is marked according to the binder mass percentage distribution L5 as a step interval, and the binder mass percentage code is recorded as f.

6. The intelligent roller pressure adjustment method according to claim 1, characterized in that: The battery electrode parameters include material system, material particle size, compaction density, surface density, conductive agent mass percentage and adhesive mass percentage, and the corresponding coefficient codes are a, b, c, d, e, and f, respectively.

7. The intelligent roller pressure adjustment method according to claim 1, characterized in that: The roller pressure data includes speed, left roller gap, right roller gap, pressure, unwinding tension and winding tension.

8. The intelligent roller pressure adjustment method according to claim 1, characterized in that: Step S5 is to perform an online elongation test on the rolled pole piece; specifically: S51 tests the spacing X before rolling and the spacing Y after rolling of a certain section of battery pole pieces The spacing before rolling is X=X2-X1, where X1 is the starting value of the battery pole piece of this section before rolling, and X2 is the end value of the battery pole piece of this section before rolling; The spacing after rolling is Y=Y2-Y1, where Y1 is the starting value of the battery pole piece of this section after rolling, and Y2 is the end value of the battery pole piece of this section after rolling; S52 calculates the spacing correction value of the battery pole piece after rolling. Y correction = (Y + Y') / 2 Among them, Y'=A° / 180°*πr, A° is the angle formed by the steel roller, and r is the radius of the steel roller; S53 calculates the elongation rate of the battery pole piece Elongation ratio = (correction of the gap Y after rolling - gap X before rolling) / gap X before rolling.

9. The intelligent roller pressure adjustment method according to claim 1, characterized in that: In step S5, a laser thickness gauge is used to perform an online thickness test on the rolled pole piece.

10. The intelligent roller pressure adjustment method according to claim 5, characterized in that: In step S12, L1 is 0.15um, L2 is 0.1g / cc, L3 is 20g / m2, L4 is 0.3, and L5 is 0.2.

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