Device and method for detecting pressure-bearing stability of electrode paste

Abstract

The invention discloses an electrode paste pressure-bearing stability detection device and method, and the device comprises a liquid accumulation disc, a positioning table is arranged at the center of the liquid accumulation disc, a circle of annular liquid accumulation groove is formed along the edge of the positioning table, and liquid flow grooves which are distributed in a central symmetry manner are formed in the positioning table; a testing cylinder is installed on a positioning table of the liquid accumulation disc, liquid flow holes are symmetrically distributed in the side wall of the testing cylinder, and a liquid flow groove and an annular boss are arranged at the bottom of the testing cylinder; a circular bottom plate is placed on the annular boss, a vertical liquid flow hole is formed in the bottom plate, and a vertical liquid flow notch is formed in the edge of the bottom plate; and a piston rod type pressure applying piece is arranged in the testing cylinder. The method solves the technical problem of detection of the pressure-bearing stability of the electrode paste, is reliable, is simple and easy to operate, and can be applied to battery technology research and quality control in the product manufacturing process.

Description

TECHNICAL FIELD

[0001] The application belongs to the technical field of battery manufacturing, and relates to an electrode paste pressure stability detection device and an electrode paste pressure stability detection method. BACKGROUND

[0002] In the battery manufacturing process, the positive electrode or negative electrode material is mixed with a dispersant according to a certain formula and process to form a positive electrode paste or a negative electrode paste, and then the positive electrode paste or the negative electrode paste is coated on the corresponding positive grid or negative grid to form the corresponding positive electrode or negative electrode after curing and drying. During the electrode paste coating process, the electrode paste pressure stability is different, which causes the difference in the dispersant precipitation amount from the electrode paste. Due to the difference in the dispersant precipitation amount, the porosity and material structure of the positive or negative active material of the battery change, thereby causing the consistency of the battery performance to fluctuate, and finally causing the service life of the battery pack to be shortened. On the other hand, when the dispersant precipitation amount is large, the lug in the corresponding positive grid or negative grid can be contaminated or oxidized, which affects the reliability of the subsequent battery assembly process welding. In order to overcome the adverse effects of the contamination or oxidation of the lug, physical polishing is usually used to remove the contaminants or oxides on the lug before assembly, which not only increases the manufacturing cost, but also causes resource waste and environmental pollution. Therefore, the dispersant pressure stability in the electrode paste is a key technical index in the field of battery manufacturing technology.

[0003] Through retrieval, no related electrode paste pressure stability detection method and detection device are found in the prior art. In view of this, how to solve the problem of electrode paste pressure stability detection has become a technical problem to be solved. SUMMARY

[0004] The purpose of the present application is to provide an electrode paste pressure stability detection device to solve the problem of poor consistency of battery performance, short actual service life of the battery pack, and low safety in the prior art.

[0005] The first technical solution adopted by the present application is an electrode paste pressure stability detection device, which comprises a liquid accumulation disc, a positioning table is arranged at the center of the liquid accumulation disc, a circular ring-shaped liquid accumulation groove is arranged along the edge of the positioning table, and liquid flow grooves are symmetrically arranged on the positioning table; a test cylinder is installed on the positioning table of the liquid accumulation disc, liquid flow holes are symmetrically arranged on the side wall of the test cylinder, a liquid flow groove and an annular boss are arranged at the bottom of the test cylinder; a circular bottom plate is placed on the annular boss, vertical liquid flow holes are arranged on the bottom plate, and vertical liquid flow notches are arranged at the edge of the bottom plate; a piston rod type pressure applying part is arranged in the test cylinder.

[0006] The present application is characterized in that, Further, the positioning table is a conical boss, and the longitudinal section is a trapezoid; the taper in the positioning table is 40:1.

[0007] Further, the liquid flow hole on the test cylinder side wall is 2-3mm in diameter; the height of the annular boss at the lower part of the test cylinder is 5-8mm.

[0008] Further, the vertical liquid flow hole in the bottom plate is 2-3mm in diameter; the vertical liquid flow gap at the edge of the bottom plate is a circular arc with the center at the point on the circumference of the edge of the bottom plate and the diameter of 3-4mm, and is evenly distributed on the circumference.

[0009] Further, the pressure applying part comprises a lower pressing plate and an upper contact plate, and the pressing plate and the contact plate are connected through a connecting rod; the circular pressing plate is adapted to the shape of the inner surface of the test cylinder.

[0010] The second technical solution adopted by the present application is an electrode paste pressure stability detection method, and the specific operation steps are as follows: Step 1, cut two square filter cloths, so that the side length is 3-4 times the diameter of the bottom plate, and weigh the mass m1 and m2 respectively; Step 2, install the bottom plate in the test cylinder and weigh the mass m3; Step 3, spread the filter cloth with a mass of m1 in the center on the upper part of the bottom plate, and make the center of the filter cloth coincide with the center of the bottom plate; Step 4, take 150-200g of electrode paste, put it into the test cylinder, and accurately weigh the sum m4 of the mass of the test cylinder, the bottom plate, the filter cloth and the electrode paste; Step 5, fold the edge part of the filter cloth to wrap the electrode paste; Step 6, install the test cylinder on the circular positioning table of the liquid accumulation disc; Step 7, place the liquid accumulation disc on the horizontal pressure testing machine workbench, install the pressure applying part, and place the lower pressing plate of the pressure applying part on the filter cloth of the electrode paste to be tested; Step 8, adjust the height of the pressure testing machine test head to make the pressure testing machine test head tightly contact with the upper contact plate of the pressure applying part; Step 9, determine the maximum output pressure of the pressure testing machine according to the pressure requirement of 0.5-1.0MPa and the area of the lower pressing plate of the pressure applying part; Step 10, set the output pressure and speed parameters of the pressure testing machine, turn on the pressure testing machine, and compress the electrode paste downward at a speed of 0.02-0.05mm / min; Step 11, when the output pressure of the pressure testing machine reaches the predetermined value, stop pressing; Step 12, take out the compressed electrode paste together with the filter cloth from the detection device, and weigh the sum m 5； Step 13, the cut filter cloth with a mass of m2 is immersed in a liquid same as the dispersant component in the electrode paste for 10-15 min; Step 14, the filter cloth after immersion of the dispersant is subjected to a blank test from step 2 to step 11 without electrode paste, and the mass m6 of the compressed filter cloth is weighed again after step 11; Step 15, the mass loss rate of the electrode paste before and after compression is calculated, which is the pressure stability of the electrode paste; (m5-m1-m6+m2) ÷ (m4-m3-m1) x 100% The mass loss rate exceeding 5% is considered unstable.

[0011] The filter cloth in step 1 is PP non-woven fabric with a specification of 100-150 g / m 2 .

[0012] The maximum output pressure of step 9 is calculated as follows: F=P x s ÷ 1000000 In the formula, F is the maximum output pressure of the pressure testing machine, unit: N; P is the pressure, unit: MPa; S is the area of the pressure plate, unit: m 2 .

[0013] The beneficial effects of the present application are: The electrode paste pressure stability detection device and method solve the technical problem of electrode paste pressure stability detection, the detection method is reliable, simple and easy to operate, and can be applied to battery technology research and product manufacturing process quality control.

[0014] The core of the detection method is to ensure that the electrode paste can withstand various mechanical stresses without failure in actual application, thereby improving the reliability, safety and life of the product, and providing a scientific basis for process optimization and product innovation. This detection is an indispensable part of the modern high-end battery and electronic equipment manufacturing process, and has important significance for promoting high-quality industrial development. BRIEF DESCRIPTION OF DRAWINGS

[0015] Figure 1 is a structural schematic diagram of the electrode paste pressure stability detection method and device of the present application in the implementation process.

[0016] Figure 2 is a structural front view of the liquid accumulation disc in the electrode paste pressure stability detection device of the present application.

[0017] Figure 3 is a structural top view of the liquid accumulation disc in the electrode paste pressure stability detection device of the present application.

[0018] Figure 4 This is a schematic front view of the test cylinder in the electrode paste pressure stability testing device of the present invention.

[0019] Figure 5 This is a schematic top view of the test cylinder in the electrode paste pressure stability testing device of the present invention.

[0020] Figure 6 This is a schematic diagram of the structure of the base plate in the electrode paste pressure stability testing device of the present invention.

[0021] Figure 7 This is a schematic diagram of the pressure-applying component in the electrode paste pressure-bearing stability testing device of the present invention.

[0022] In the diagram, 1. Liquid collection tray; 11. Liquid collection trough; 12. Positioning platform; 13. Liquid flow channel; 14. Conical surface; 2. Test cylinder; 21. Liquid flow hole; 22. Liquid flow channel; 23. Annular boss; 3. Base plate; 31. Vertical liquid flow hole; 32. Vertical liquid flow notch; 4. Pressure application component; 41. Pressure plate; 42. Contact plate; 43. Connecting rod; 5. Electrode paste; 6. Filter cloth. Detailed Implementation

[0023] The embodiments of the present invention will now be described in detail with reference to the accompanying drawings.

[0024] Example 1 The electrode paste pressure-bearing stability testing device of the present invention, such as Figures 1-7 As shown, the device includes a liquid collection tray 1, a positioning platform 12 at the center of the liquid collection tray 1, and a circular liquid collection groove 11 along the edge of the positioning platform 12. The positioning platform 12 has symmetrically distributed liquid flow grooves 13. A test cylinder 2 is mounted on the positioning platform 12 of the liquid collection tray 1. The test cylinder 2 has symmetrically distributed liquid flow holes 21 on its sidewalls, liquid flow grooves 13 and annular bosses 23 at its bottom. A circular base plate 3 is placed on the annular boss 23. The base plate 3 has vertical liquid flow holes 31 and vertical liquid flow notches 32 along its edge. A piston rod type pressure device 4 is installed inside the test cylinder 2.

[0025] Example 2 The present invention relates to an electrode paste pressure-bearing stability testing device, comprising a liquid accumulation pan 1, a positioning platform 12 at the center of the liquid accumulation pan 1, a circular liquid accumulation groove 11 along the edge of the positioning platform 12, and a centrally symmetrically distributed liquid flow groove 13 on the positioning platform 12; a test cylinder 2 is mounted on the positioning platform 12 of the liquid accumulation pan 1, the test cylinder 2 has symmetrically distributed liquid flow holes 21 on its side wall, and a liquid flow groove 13 and an annular boss 23 at its bottom; a circular base plate 3 is placed on the annular boss 23, the base plate 3 has vertical liquid flow holes 31 and vertical liquid flow notches 32 at its edge; and a piston rod type pressure application component 4 is provided inside the test cylinder 2.

[0026] The positioning platform 12 is a conical convex platform, and the vertical section is trapezoidal; the inner taper of the positioning platform 12 is 40:1.

[0027] Embodiment 3 On the basis of embodiment 2, the liquid flow hole 21 on the side wall of the test cylinder 2 is symmetrically distributed, and the aperture is 2-3 mm; the height of the annular convex platform 23 at the lower part of the test cylinder 2 is 5-8 mm.

[0028] The vertical liquid flow hole 31 in the bottom plate 3 has an aperture of 2-3 mm; the vertical liquid flow gap 32 at the edge of the bottom plate 3 is a circular arc with the center at the point on the circumference of the edge of the bottom plate and the diameter of 3-4 mm, and is uniformly distributed on the circumference.

[0029] On the basis of embodiment 3, the pressure applying part 4 includes a lower pressure plate 41 and an upper contact plate 42, and the pressure plate 41 and the contact plate 42 are connected through a connecting rod 43; the circular pressure plate 41 is adapted to the shape of the inner surface of the test cylinder.

[0030] Embodiment 4 The electrode paste pressure stability detection method specifically includes the following steps: Step 1, cut two square pieces with the specification of 145 g / m 2 Filter cloth, make the side length 3 times the diameter of the bottom plate, and respectively weigh the mass m1 and m2; Step 2, install the bottom plate in the test cylinder, and weigh the mass m3; Step 3, spread the filter cloth with the mass m1 at the center on the upper part of the bottom plate, and make the center of the filter cloth coincide with the center of the bottom plate; Step 4, take 150 g of electrode paste, put it into the test cylinder, and accurately weigh the sum m4 of the mass of the test cylinder, the bottom plate, the filter cloth and the electrode paste; Step 5, fold the edge part of the filter cloth, and wrap the electrode paste; Step 6, install the test cylinder on the circular positioning platform of the liquid accumulation disc; Step 7, place the liquid accumulation disc on the horizontal pressure testing machine workbench, install the pressure applying part, and place the lower pressure plate of the pressure applying part on the filter cloth of the electrode paste to be tested; Step 8, adjust the height of the pressure testing machine testing head, so that the pressure testing machine testing head is in close contact with the upper contact plate of the pressure applying part; Step 9, determine the maximum output pressure of the pressure testing machine according to the pressure requirement of 0.5 MPa and the area of the lower pressure plate of the pressure applying part; Step 10, set the output pressure and speed parameters of the pressure testing machine, and start the pressure testing machine to compress the electrode paste downward at the speed of 0.02 mm / min; Step 11, stop pressing when the output pressure of the pressure testing machine reaches the predetermined value; Step 12, take out the compressed electrode paste together with the filter cloth from the detection device, and weigh the sum of their masses m 5； Step 13, immerse the cut filter cloth with a mass of m2 in a liquid identical to the dispersant component in the electrode paste for 10 min; Step 14, perform a blank test on the filter cloth after immersion of the dispersant without electrode paste from step 2 to step 11, and weigh the mass of the compressed filter cloth m6 again after step 11 is completed; Step 15, calculate the mass loss rate of the electrode paste before and after compression, which is the pressure stability of the electrode paste; (m5-m1-m6+m2) ÷ (m4-m3-m1) x 100% A mass loss rate exceeding 5% is considered unstable.

[0031] Example 5 The electrode paste pressure stability detection method has the following specific operation steps: Step 1, cut two square filter cloths with a size of 120 g / m 2 The length of the side is 4 times the diameter of the base plate, and their masses m1 and m2 are weighed respectively; Step 2, install the base plate in the test cylinder and weigh its mass m3; Step 3, lay the filter cloth with a mass of m1 flat in the center of the upper part of the base plate, and make the center of the filter cloth coincide with the center of the base plate; Step 4, take 200 g of electrode paste, put it into the test cylinder, and accurately weigh the sum of the masses of the test cylinder, the base plate, the filter cloth, and the electrode paste m4; Step 5, fold the edge part of the filter cloth to wrap the electrode paste; Step 6, install the test cylinder on the circular positioning table of the liquid accumulation disc; Step 7, place the liquid accumulation disc on the horizontal pressure testing machine workbench, install the pressing member, and place the pressing plate at the lower part of the pressing member on the filter cloth of the electrode paste to be tested; Step 8, adjust the height of the pressure testing machine test head to make the pressure testing machine test head tightly contact with the contact plate at the upper part of the pressing member; Step 9, determine the maximum output pressure of the pressure testing machine according to the pressure requirement of 1.0 MPa and the area of the pressing plate at the lower part of the pressing member; Step 10, set the output pressure and speed parameters of the pressure testing machine, and start the pressure testing machine to compress the electrode paste downward at a speed of 0.05 mm / min; Step 11, stop pressing when the output pressure of the pressure testing machine reaches the predetermined value; Step 12, the compressed electrode paste is taken out from the testing device together with the filter cloth, and the total mass m is weighed 5； Step 13, the cut filter cloth with mass m2 is immersed in the same liquid as the dispersant component in the electrode paste for 15 min; Step 14, the filter cloth after being immersed in the dispersant is subjected to a blank test from step 2 to step 11 without electrode paste, and the mass m6 of the compressed filter cloth is weighed again after step 11 is completed; Step 15, the mass loss rate of the electrode paste before and after compression is calculated, which is the pressure stability of the electrode paste; (m5-m1-m6+m2) ÷ (m4-m3-m1) x 100%.

[0032] The mass loss rate exceeding 5% is considered unstable.

[0033] Example 6 On the basis of example 5, the filter cloth in step 1 is PP non-woven fabric with a specification of 100-150 g / m 2 .

[0034] Step 9, the calculation method of the maximum output pressure is as follows: F=P x s ÷ 1000000 In the formula: F is the maximum output pressure of the pressure testing machine, unit: N; Q is the pressure, unit: MPa; S is the area of the pressure plate, unit: m 2 .

Claims

1. An electrode paste pressure stability detection device characterized by comprising: The application relates to a liquid accumulation disc (1) which is provided with a positioning table (12) in the center, a circular ring-shaped liquid accumulation groove (11) is arranged along the edge of the positioning table (12), and a liquid flow groove (13) is symmetrically arranged on the positioning table (12); a test cylinder (2) is arranged on the positioning table (12) of the liquid accumulation disc (1), liquid flow holes (21) are symmetrically arranged on the side wall of the test cylinder (2), a liquid flow groove (13) and an annular boss (23) are arranged at the bottom of the test cylinder (2), a circular bottom plate (3) is arranged on the annular boss (23), vertical liquid flow holes (31) are arranged on the bottom plate (3), and vertical liquid flow notches (32) are arranged at the edge of the bottom plate (3); a piston rod type pressure applying part (4) is arranged in the test cylinder (2).

2. The electrode paste pressure stability detection device according to claim 1, characterized by The positioning table (12) is a conical boss, and the longitudinal section is trapezoidal; the inner taper of the positioning table (12) is 40:

1.

3. The electrode paste pressure stability detection device according to claim 1, characterized by The diameter of the liquid flow holes (21) symmetrically arranged on the side wall of the test cylinder (2) is 2-3 mm; and the height of the annular boss (23) at the lower part of the test cylinder (2) is 5-8 mm.

4. The electrode paste pressure stability detection device according to claim 1, characterized by The diameter of the vertical liquid flow holes (31) in the bottom plate (3) is 2-3 mm; and the vertical liquid flow notches (32) at the edge of the bottom plate (3) are circular arcs with the center being the point on the circumference of the edge of the bottom plate and the diameter being 3-4 mm, and the circular arcs are uniformly distributed on the circumference.

5. The electrode paste pressure stability detection device according to claim 1, characterized by The pressure applying part (4) comprises a lower pressing plate (41) and an upper contact plate (42), the pressing plate (41) and the contact plate (42) are connected through a connecting rod (43), and the pressing plate (41) is matched with the inner surface of the test cylinder.

6. A method for detecting pressure stability of electrode paste, characterized by The specific operation steps are as follows: Step 1, two square filter cloths are cut, the side length is 3-4 times of the diameter of the bottom plate, and the mass m1 and m2 of the filter cloths are respectively measured; Step 2, the bottom plate is installed in the test cylinder, and the mass m3 of the bottom plate is measured; Step 3, the filter cloth with the mass m1 is laid flat on the upper part of the bottom plate, and the center of the filter cloth is coincided with the center of the bottom plate; Step 4, 150-200 g of electrode paste is filled into the test cylinder, and the total mass m4 of the test cylinder, the bottom plate, the filter cloth and the electrode paste is accurately measured; Step 5, the edge part of the filter cloth is folded to wrap the electrode paste; Step 6, the test cylinder is installed on the circular positioning table of the liquid accumulation disc; Step 7, the liquid accumulation disc is placed on the horizontal workbench of a pressure testing machine, the pressure applying part is installed, and the lower pressing plate of the pressure applying part is placed on the filter cloth of the electrode paste to be tested; Step 8, the height of the testing head of the pressure testing machine is adjusted, so that the testing head of the pressure testing machine is in close contact with the upper contact plate of the pressure applying part; Step 9, the maximum output pressure of the pressure testing machine is determined according to the pressure requirement of 0.5-1.0 MPa and the area of the lower pressing plate of the pressure applying part; Step 10, the output pressure and speed parameters of the pressure testing machine are set, the pressure testing machine is started, and the electrode paste is compressed downwards at the speed of 0.02-0.05 mm / min; Step 11, when the output pressure of the pressure testing machine reaches the predetermined value, the pressure applying is stopped; Step 12, the compressed electrode paste is taken out from the detection device together with the filter cloth, and the total mass m is weighed 5； Step 13, the cut filter cloth with the mass m2 is immersed in a liquid which is the same as the dispersant component in the electrode paste for 10-15 min. Step 14, the filter cloth after immersion dispersant in the case without adding electrode paste, from step 2 to step 11, after step 11, the mass of the compressed filter cloth m6 is weighed again; Step 15, the mass loss rate of electrode paste before and after compression is calculated, which is the pressure stability of electrode paste; (m5-m1-m6+m2) ÷ (m4-m3-m1) × 100% The mass loss rate more than 5% is considered unstable.

7. The method according to claim 6, wherein The filter cloth described in Step 1 is PP non-woven fabric with a specification of 100-150 g / m 2 .

8. The method for detecting pressure stability of electrode paste according to claim 6, characterized by, Step 9, the calculation method of maximum output pressure is as follows: F=P×s÷1000000 In the formula: F--- is the maximum output pressure of the pressure testing machine, unit is N; R--- is the pressure, unit is MPa; S— the area of the presser plate in m2 2 .

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