Search

CN-122016564-A - Battery powder material wettability testing system and method

CN122016564ACN 122016564 ACN122016564 ACN 122016564ACN-122016564-A

Abstract

The application provides a system and a method for testing wettability of a battery powder material, which relate to the technical field of battery material testing and comprise a sample storage device, a liquid injection assembly, a conductor and a resistance tester, wherein the sample storage device is provided with a sample storage cavity and a liquid injection channel communicated with the sample storage cavity, the two ends of the sample storage cavity along a first direction are opened and are suitable for being filled with test powder, and the liquid injection channel extends along a second direction and is communicated with the liquid injection assembly; the two conductors are connected with the sample storage cavity in a sliding mode along the first direction, the two conductors correspond to openings at two ends of the sample storage cavity one by one to seal the openings, the conductors are suitable for being connected with an external pressure device to press test powder into a sample, and the conductors are abutted to the sample and are electrically connected with the resistance tester. According to the application, the compacted mixed powder is subjected to the infiltration performance test, so that the test process is closer to the actual use state of the powder, whether the powder is completely infiltrated or not can be accurately judged, the whole structure is simple, the test error is small, and the test cost is low.

Inventors

  • WANG HONGHU

Assignees

  • 万华化学集团电池科技有限公司
  • 万华化学(烟台)电池产业有限公司
  • 万华化学(烟台)电池材料科技有限公司

Dates

Publication Date
20260512
Application Date
20241031

Claims (10)

  1. 1. A battery powder material wettability testing system, comprising: The sample storage device (1) is provided with a sample storage cavity (11) and a liquid injection channel (12) communicated with the sample storage cavity (11), the two ends of the sample storage cavity (11) along a first direction are open and are suitable for being filled with test powder, and the liquid injection channel (12) extends along a second direction and is communicated with the liquid injection component (2) so as to be filled with electrolyte to infiltrate the test powder, and the second direction forms an included angle with the first direction; the conductors (3) are connected with the sample storage cavity (11) in a sliding way along the first direction, the two conductors (3) are in one-to-one correspondence with openings at two ends of the sample storage cavity (11) so as to block the openings, the conductors (3) are suitable for being connected with an external pressure device so as to press test powder into a sample, and And the electric conductor (3) is abutted with the sample and is electrically connected with the resistance tester (4) so as to measure the internal resistance of the sample.
  2. 2. The battery powder material wettability test system according to claim 1, wherein the number of the liquid injection channels (12) is plural, and the liquid injection components (2) are plural and are in one-to-one correspondence with the liquid injection channels (12); Or the liquid injection component (2) is provided with one liquid distribution pipe, the liquid distribution pipe is provided with a liquid inlet end and a plurality of liquid outlet ends, the liquid outlet of the liquid injection component (2) is communicated with the liquid inlet end of the liquid distribution pipe, and a plurality of liquid injection channels (12) are communicated with the liquid outlet ends of the liquid distribution pipe in a one-to-one correspondence manner.
  3. 3. The battery powder material wettability testing system according to claim 1 or 2, further comprising a negative pressure bin (5), wherein the negative pressure bin (5) is provided with a negative pressure cavity (51), and the sample storage device (1) is located in the negative pressure cavity (51) so as to test the wettability of the sample in a negative pressure state.
  4. 4. A battery powder material wettability test system according to claim 3, characterized in that the liquid injection assembly (2) comprises a liquid injection device (21) and a liquid injection funnel (22), the liquid injection device (21) is detachably connected with the negative pressure bin (5), a liquid outlet end of the liquid injection device (21) is located in the negative pressure cavity (51) and is communicated with a liquid inlet of the liquid injection funnel (22), the liquid injection funnel (22) is located in the negative pressure cavity (51), and a liquid outlet of the liquid injection funnel (22) is communicated with the liquid injection channel (12).
  5. 5. A method for testing wettability of a battery powder material based on the battery powder material wettability testing system according to any one of claims 1 to 4, comprising the steps of: filling a sample storage cavity (11) with a test powder with a preset weight, and plugging an opening of the sample storage cavity (11) by an electric conductor (3); Applying pressure to the conductor (3) by an external pressure device, wherein the conductor (3) slides along a first direction and extrudes the test powder so as to press a sample; The electric conductor (3) is electrically connected with the resistance tester (4), electrolyte is injected into the sample through the liquid injection channel (12) by the liquid injection component (2), and the change condition of the internal resistance of the sample along with the liquid injection amount and the infiltration time is obtained; and calculating the total liquid absorption, infiltration rate, compaction density and liquid injection coefficient of the test powder.
  6. 6. The method according to claim 5, wherein, before the step of electrically connecting the electrical conductor (3) with the resistance tester (4), the electrolyte is injected into the sample through the liquid injection channel (12) by the liquid injection assembly (2), and the internal resistance of the sample is obtained as a function of the amount of injected liquid and the time of infiltration, the method further comprises: The sample storage device (1) is placed in the negative pressure cavity (51), and the air pressure of the negative pressure cavity (51) is kept to be set negative pressure.
  7. 7. The method for testing wettability of a battery powder material according to claim 5, wherein the total liquid absorption of the test powder is calculated by the following formula: G=G′-G 0 Wherein G is the total liquid absorption amount of the test powder, G' is the total weight of the sample storage device (1), the sample and the two conductors (3) when the sample is completely infiltrated, and G 0 is the total weight of the sample storage device (1), the sample and the two conductors (3) before the sample is infiltrated.
  8. 8. The method of claim 7, wherein calculating the infiltration rate of the test powder comprises: and calculating the infiltration time of the test powder by the following formula: Δt=t 1 -t 0 Wherein Δt is the infiltration time of the test powder, t 1 is the complete infiltration time when the internal resistance of the sample no longer changes with time, and t 0 is the initial time of injecting the electrolyte into the sample; Based on the infiltration time of the test powder and the total liquid absorption amount of the test powder, calculating the infiltration rate of the test powder by the following formula: wherein v is the infiltration rate of the test powder, and G is the total liquid absorption of the test powder.
  9. 9. The method of claim 7 or 8, wherein the calculating the compacted density of the test powder comprises: The volume of the sample was calculated by the following formula: V=S·(L-2l) Wherein V is the volume of the sample, S is the cross-sectional area of the projected outer contour of the sample storage cavity (11) on a projection plane perpendicular to a first direction, L is the distance between the ends of the two conductors (3) extending out of the sample storage cavity (11) along the first direction, and L is the length of the conductors (3) along the first direction; based on the volume of the sample and the predetermined weight of the test powder, the compacted density of the test powder is calculated by the following formula: Where ρ is the compacted density of the test powder and a is the predetermined weight of the test powder.
  10. 10. The method for testing wettability of a battery powder material according to claim 9, wherein the calculating the liquid injection amount coefficient of the test powder includes: Based on the volume of the sample, the porosity of the sample is calculated by the following formula: δ=V-V Conductive agent -V Adhesive agent -V Main material Wherein δ is the pore of the sample, V Conductive agent is the true volume of the conductive agent in the test powder, V Adhesive agent is the true volume of the binder in the test powder, and V Main material is the true volume of the main material in the test powder; Based on the pores of the sample and the total liquid absorption of the test powder, the liquid injection amount coefficient of the test powder is calculated by the following formula: Wherein epsilon is the liquid injection amount coefficient of the test powder, and G is the total liquid absorption amount of the test powder.

Description

Battery powder material wettability testing system and method Technical Field The application relates to the technical field of battery material testing, in particular to a system and a method for testing wettability of a battery powder material. Background The battery is a device for converting chemical energy into electric energy, and factors influencing the performance of the battery are more, wherein the infiltration effect of a battery pole piece material on electrolyte is one of important indexes for evaluating the performance of the battery, and poor infiltration can cause the increase of the interface resistance of the battery to influence the multiplying power performance, the discharge capacity and the cycle life of the battery, so that the infiltration of the pole piece material before the battery is manufactured is required to be studied. In the related art, for the test of the pole piece infiltration performance, only the pole piece infiltration rate is often tested, or the pole piece infiltration rate is judged by a long-time infiltration mode, and whether the pole piece is completely infiltrated cannot be determined, so that the test error is large, the limitation is strong, in addition, the powder material is manufactured into the pole piece for testing, and the test method is complex, time and labor are wasted, and the cost is high. Disclosure of Invention The present application aims to solve at least one of the technical problems in the related art to some extent. Therefore, an embodiment of an aspect of the present application provides a battery powder material wettability testing system, which performs wettability testing on compacted mixed powder, so that a testing process is closer to an actual use state of the powder, and whether the powder is completely infiltrated can be accurately judged. An embodiment of another aspect of the present application provides a method for testing wettability of a battery powder material. The battery powder material wettability testing system comprises a sample storage device, a liquid injection assembly, electric conductors and a resistance tester, wherein the sample storage device is provided with a sample storage cavity and a liquid injection channel communicated with the sample storage cavity, the sample storage cavity is opened at two ends along a first direction and is suitable for being filled with test powder, the liquid injection channel extends along a second direction and is communicated with the liquid injection assembly so as to be filled with electrolyte to infiltrate the test powder, the second direction forms an included angle with the first direction, the electric conductors are two and are slidably connected with the sample storage cavity along the first direction, the two electric conductors are in one-to-one correspondence with openings at two ends of the sample storage cavity so as to block the openings, the electric conductors are suitable for being connected with an external pressure device so as to press the test powder into a sample, and the electric conductors are abutted with the sample and are electrically connected with the resistance tester so as to measure the internal resistance of the sample. According to the battery powder material wettability test system provided by the embodiment of the application, the opening of the sample storage cavity in the sample storage device can be used for filling test powder into the sample storage cavity, the conductor can be used for plugging the opening and is matched with the external pressure device, so that the compaction treatment of the test powder in the sample storage cavity is completed, the sample is obtained, then, the connection between the conductor and the external pressure device is released, the conductor is connected with the resistance tester, electrolyte is injected into the sample through the liquid injection channel through the liquid injection component, so that the wettability test is carried out on the sample, in the test process, the conductor is abutted against the sample, a closed loop can be formed among the sample, the two conductors and the resistance tester, the resistance tester can be used for measuring the change condition of the internal resistance of the sample along with the liquid injection quantity and the infiltration time in real time, and the sample can be completely infiltrated when the internal resistance of the sample is not changed any more, so that compared with the related technology, the compacted mixed powder is subjected to the wettability test, the actual use state of the powder is more approximate to the test process, the whole structure is simple, the test error is easy, and the test cost is low. In some embodiments, the liquid injection channels are multiple, and the liquid injection components are multiple and correspond to the liquid injection channels one by one; Or the liquid injection component is provided with one liquid distr