Introduction to the battery ear
The polar ear is a raw material for lithium ion polymer battery products. For example, the mobile phone batteries used in our lives, Bluetooth batteries, laptop batteries, etc. need to use the ear. The battery is divided into positive and negative poles. The ear is the metal conductor that leads the positive and negative poles from the battery. It is common to say that the ears of the positive and negative poles of the battery are the contact points when charging and discharging.
This point of contact is not the copper piece that we see on the outside of the battery, but a connection inside the battery. The ear is divided into three materials, the anode of the battery is made of aluminum (Al) material, the negative electrode is made of nickel (Ni) material, and the negative electrode is also made of nickel-plated nickel (Ni-Cu) material, which are both made of film and metal strip. Into, as shown in Figure 1.
The film is a part of the ear insulator, which prevents the short circuit between the metal strip and the aluminum plastic film when the battery is packaged, and is sealed by heat-sealing with the aluminum plastic film by heating (about 140 ° C). Leakage. One of the tabs is sandwiched between two strips of metal tape.
Currently used in the market are three kinds of film: black glue, white glue and single layer glue. The commonly used black film is a three-layer structure: melanin, melting point 66 ° C; PE, melting point 105 ° C; PP, melting point 137 ° C. The finished product package of the ear is divided into a disc type (the whole metal strip is wound into a disc after passing the equipment plus the film) and a plate type (the metal strip is cut into a single piece after the film is attached, and then placed in a row with two A thin transparent plastic sheet is sandwiched in the middle.
Polar production process
1. Cut the metal strip of the base material into segments according to the specified length.
2, ultrasonic cleaning
4. Surface treatment of the metal strip treatment solution
5, wash with deionized water
7. Fix the size of the ear rubber and metal tape with PET and double-sided tape.
8, hot pressing
9, room temperature cooling
10, cutting edge material
11. The solvent for ultrasonic cleaning is acetone.
12. The drying temperature is 70~80°C for 3 hours.
13. Composition of treatment liquid: NaF 0.8~2g/L, Cro3 4~6g/L, K2Cr2O7 0.8~2g/L Solvent is deionized water
14, surface treatment time 60 seconds
15, deionized water needs to be rinsed 4 times
16, the second drying temperature of 90 ~ 100 ° C, time 4 hours
17. The above process is suitable for nickel stripping. If the above metal is an aluminum strip, it is necessary to increase the pretreatment process after one drying.
18. The pretreatment step is to clean the aluminum strip after washing with a concentration of 0.2 mol/L potassium hydroxide for 3 to 5 minutes.
19. If the treated metal is a copper strip, the following pretreatment process is added before the first drying and surface treatment with the treatment liquid: the washed copper strip is washed with 0.1~0.3 mol of dilute hydrochloric acid for 3 to 10 minutes, and then Rinse with deionized water.
After adopting the above solution, the manufacturing process of the lithium battery tab of the present invention is effective for removing the surface of the metal strip by adding pretreatment and surface treatment of the metal strip of the tab substrate or surface treatment of the metal strip of the tab substrate. Oxide, and increase the surface activity of the metal strip, so that the bonding strength of the metal surface and the sealant is improved, so that the anti-electrolyte attack ability is enhanced, thereby improving the sealing performance of the battery core, and the service life of the lithium battery is improved. 3 to 6 months extended to 3 years.
The manufacturing process of the lithium battery tab of the present invention is as follows:
A. First, the aluminum strip of the tab substrate is cut into sections;
B. Ultrasonic cleaning of the cut aluminum strip in an acetone solvent;
C. Dry the cleaned aluminum strip for 3 hours in an environment with a temperature of 30-80 °C.
D, pretreatment, the cleaned aluminum strip is washed with 0.1-0.3mol of water for 30~5min,
E, treatment solution: NaF 0.8~2g/L, Cro3 4~6g/L, K2Cr2O7 0.8~2g/L solvent for deionized water surface treatment surface treatment time 60 seconds
F.deionized water needs to be rinsed 4 times
G. secondary drying temperature 90~100°C, time 4 hours
Sealing agent (Sealant) with PET and double-sided tape and pre-treated and surface-treated aluminum tape to ensure the size meets the requirements;
Then use a flat press to hot-press the fixed half-finished product, the hot-pressing temperature is controlled between 120~200, the time is between 30S~3min, and the surface pressure of the flat press is controlled at 30~50Mpa. Ear final thickness reference value = initial thickness of the ear gel x85% + metal ear thickness)
The semi-finished product after hot pressing is cooled at room temperature for 30~90 minutes.