CN-119092630-B - Battery pole piece for performance test and preparation method thereof

Abstract

The application belongs to the field of pole piece testing, in particular to a battery pole piece for performance testing and a preparation method thereof, wherein the battery pole piece and the preparation method thereof replace the traditional compaction density testing method to roll the pole piece, namely, the target compaction rate is calculated to be 58 percent plus or minus 1 percent according to the target compaction density of active substances, according to the target compaction rate, the target rolling thickness d Target object of the pole piece is calculated, and whether the pole piece is qualified or not can be rapidly judged only by comparing the thickness of the pole piece after rolling with the target rolling thickness d Target object in the process of rolling in the follow-up process, so that the rolling efficiency is effectively improved.

Inventors

• LI LI
• LIU GUANGHAO
• YE WULONG
• LIU XIAOLIN

Assignees

• 湖南林特聚能科技有限公司

Dates

Publication Date

20260512

Application Date

20240827

Claims (5)

1. 1. The preparation method of the battery pole piece for performance test is characterized by comprising the following steps: S1, cutting the coated and dried original pole piece into pole pieces with the specification of 30mm multiplied by 300mm by using a tool knife, respectively measuring the thickness of five different positions of each cut pole piece, selecting the pole piece with the thickness error of <2 mu m, taking the average value of the thicknesses of the five different positions as the thickness d 0 of the original pole piece, and calculating the target rolling thickness d Target object according to the following formula: d 1 ≤d Target object ≤d 2 d 1 =(d 0 - d cf )•(100-（58-1）)%+d cf; d 2 =(d 0 - d cf )•(100-（58+1）)%+d cf; Wherein d 0 is the thickness of the initial pole piece, d cf is the thickness of the current collector, and the target rolling thickness d Target object is an integer; S2, setting the linear speed of the double rollers of the electric pair roller to be 2.0m/min, taking 2Mpa as a rolling pressure starting value, placing the pole pieces selected in the step S1 into the electric pair roller for rolling after the pressure is stable, and sequentially overlapping the rolling pressure in an upward manner at an increment of 0.5Mpa until the pole pieces reach the two sides and are wavy, wherein vertical lines appear in the middle of the pole pieces; S3, measuring the thicknesses of five different positions of the rolled pole piece by using a micrometer, wherein the pole piece which meets the target rolling thickness d Target object and has the thickness value difference of less than 2 mu m at any two positions is a qualified pole piece; S4, recording an average value d Real world of thicknesses of five different positions on the qualified pole piece, and calculating an actual compaction rate R Real world according to the following formula: R Real world =1–{（d Real world - d cf ）÷（d 0 - d cf ）}•100% ; Judging whether R Real world is within 58% +/-1%, if so, judging that the product is qualified, and if not, judging that the product is unqualified.
2. 2. The method for manufacturing a battery pole piece according to claim 1, wherein in the step S1, the drying condition is that the battery pole piece is placed in an oven at 110 ℃ to 130 ℃ for 3 to 5 hours.
3. 3. The method of manufacturing a battery pole piece according to claim 2, wherein in step S1, the drying condition is that the battery pole piece is put into an oven at 120 ℃ for 4 hours.
4. 4. The method for preparing a battery pole piece according to claim 1, wherein the method for preparing a battery pole piece is carried out under the conditions that the temperature is 25+/-1 ℃ and the humidity is less than or equal to 60% RH except for drying in the step S1.
5. 5. A battery pole piece for performance testing, characterized in that the battery pole piece is manufactured by the battery pole piece manufacturing method according to any one of claims 1-4.

Description

Battery pole piece for performance test and preparation method thereof Technical Field The application relates to the technical field of pole piece testing, in particular to a battery pole piece for performance testing and a preparation method thereof. Background The pole piece is an important link in battery production, and the performance of the pole piece directly influences the stability of the following procedures and the performance and safety of the battery core, so the evaluation of the pole piece performance is particularly effective, wherein the resistivity and the peel strength of the pole piece are used as important indexes for evaluating the pole piece performance, and the pole piece takes an irreplaceable position in battery research and development and production. Before resistivity and peel strength are tested, the rolled positive/negative plates are required to be taken, and the plates are cut by a custom-made cutting die. At present, in order to ensure that the electrode plate reaches the required compaction density in the process of rolling the electrode plate, a method for testing the compaction density of the electrode plate of the battery cathode material, disclosed in a patent CN 107655791A, is generally adopted in the process of rolling, the weight of the cut electrode plate and the weight of the current collector are required to be measured, the thicknesses of 3 different positions of the electrode plate rolled under different pressures are also required to be measured, and the thicknesses are calculated through an electrode plate surface density calculation formula and a compaction density calculation formula, so that the operation is difficult, the process is complicated, the rolling efficiency is lower, and the preparation efficiency of the battery electrode plate is influenced. Disclosure of Invention The embodiment of the application provides a battery pole piece for performance test and a preparation method thereof, aiming at improving the preparation efficiency of the battery pole piece. To this end, according to one aspect of the present application, there is provided a battery pole piece manufacturing method for performance testing, comprising the steps of: S1, cutting the coated and dried original pole piece into pole pieces with the specification of 30mm multiplied by 300mm by using a tool knife, respectively measuring the thickness of five different positions of each cut pole piece, selecting the pole piece with the thickness error of <2 mu m, taking the average value of the thicknesses of the five different positions as the thickness d 0 of the original pole piece, and calculating the target rolling thickness d Target object according to the following formula: d1≤d Target object ≤d2 d1＝(d0-dcf)·(100-(58-1))％+dcf d2＝(d0-dcf)·(100-(58+1))％+dcf Wherein d 0 is the thickness of the initial pole piece, d cf is the thickness of the current collector, and the target rolling thickness d Target object is an integer; S2, setting the linear speed of the double rollers of the electric pair roller to be 2.0m/min, taking 2Mpa as a rolling pressure starting value, placing the pole pieces selected in the step S1 into the electric pair roller for rolling after the pressure is stable, and sequentially overlapping the rolling pressure in an upward manner at an increment of 0.5Mpa until the pole pieces reach the two sides and are wavy, wherein vertical lines appear in the middle of the pole pieces; S3, measuring the thicknesses of five different positions of the rolled pole piece by using a micrometer, wherein the pole piece which meets the target rolling thickness d Target object and has the thickness value difference of less than 2 mu m at any two positions is a qualified pole piece. Optionally, after step S3, the method further includes the following steps: S4, recording an average value d Real world of thicknesses of five different positions on the qualified pole piece, and calculating an actual compaction rate R Real world according to the following formula: R Real world ＝1–{(d Real world -dcf)÷(d0-dcf)}·100% Judging whether R Real world is within 58% +/-1%, if so, judging that the product is qualified, and if not, judging that the product is unqualified. Optionally, in step S1, the drying condition is that the oven is placed for 3 to 5 hours at 110-130 ℃. Optionally, in step S1, the drying conditions are set in an oven at 120 ℃ for 4 hours. Optionally, the preparation method of the battery pole piece is carried out under the conditions that the humidity is less than or equal to 60% RH and the temperature is 25+/-1 ℃ except for drying in the step S1. According to another aspect of the present application, there is provided a battery pole piece for performance testing, the battery pole piece being manufactured by the battery pole piece manufacturing method as described above. Compared with the prior art, the battery pole piece for performance test and the preparation method