Pacific Automotive Network uses copper foil for blade batteries. When producing blade batteries, graphite and some auxiliary materials are first mixed and mixed into a slurry, and then applied to the copper foil. The copper foil unfolds quickly. of 70 meters per minute, after coating, it is sent to the oven for drying and then rolled.
Why do lithium batteries use copper foil for the negative electrode and aluminum foil for the positive electrode?
1. Both are used as current collectors because they have good conductivity, have a relatively soft texture (perhaps this will also be beneficial for bonding), are relatively common and cheap, and both surfaces can be formed. protective oxide film.
2. The oxide layer on the copper/nickel surface is a semiconductor, and electrons are conductive if the layerhe oxide is too thick, the resistance is large while the oxide layer on the surface of the aluminum. Aluminum oxide is an insulator and the oxide layer cannot conduct electricity, but due to its very fine electronic conductivity it is achieved by tunneling. If the oxide layer is thicker, the conductivity of the aluminum foil is poor or even mediocre. isolated. Generally, it is better to clean the surface of current collectors before use, on the one hand, the oil stains can be removed, and at the same time the thick oxide layer can be removed.
3. The positive electrode potential is high, and the thin aluminum oxide layer is very dense, which can prevent the current collector from oxidizing. The oxide layer of the copper/nickel foil is relatively loose. In order to avoid oxidation, it is preferable to have a lower potential. At the same time, it is difficult for the Lito form an alloy inlaid with lithium with Cu/nickel. low potential However, if the copper/nickel surface is heavily oxidized, the potential will be lower at a slightly higher potential. The Li will react with the copper/nickel oxide to insert lithium at the potential. Aluminum foil cannot be used as a negative electrode because the LiAl alloy will perform at low potential.
4. The current collector requires pure components. The impure composition of Al will make the surface film non-dense and cause pitting corrosion. Additionally, damage to the surface film will result in the formation of LiAl alloy.
(Images/Text/Photos: Pacific Automotive Network Q&A)
What other secrets don't we know about lithium batteries?
Under normal circumstances, lithium iron phosphate batteries will not explode. To be more extreme, batteries are generally equisafety valves (cylindrical and aluminum shells) to release pressure. Flexible packaging is more likely to deflate and release pressure, making it less likely to explode. Therefore, the explosion of lithium iron phosphate batteries under extreme circumstances is an unlikely event. Of course, there will always be unexpected situations, such as violent impact during an accident, which can cause spontaneous combustion and explosion. Of course, compared to other types of lithium batteries, they will be relatively "soft", so you need one. cork. Fire-resistant shell (iron box, aluminum shell or flame-retardant rubber shell) requires a reliable protection panel, and flame-retardant materials are used for internal wiring harness/filler fixing accessories.
When it comes to lithium batteries, I think all monde knows them very well. After all, everyone must carry a mobile phone with a lithium battery when going out. This is already an essential element. of the equipment. Lithium batteries play an important role in electronic products such as cell phones and computers, but how much do you know about lithium batteries? Today we're going to talk about the secrets you don't know about lithium-ion batteries.
Lithium battery is a secondary battery (rechargeable battery) that primarily relies on the movement of lithium ions between positive and negative electrodes to function. During the charging and discharging process, Li+ is integrated between the two electrodes.And deintercalation: During charging, Li+ is deintercalated from the positive electrode and integrated into the negative electrode through the electrolyte. The negative electrode is in a lithium-rich state; the opposite is true duringdump. That is to say, the lithium battery may appear calm on the surface during use, but in fact the small lithium ions inside have been moving back and forth desperately to achieve our charging and discharging. Additionally, the constant current and constant voltage charging characteristics of lithium-ion batteries determine that their deep charging time does not require 12 hours.
Lithium batteries are mainly made of a positive electrode - the active material is usually lithium cobalt oxide separator - PP or PE composite film; a negative electrode - the active material is an organic carbon electrolyte; cinema, etc. The production process includes pulping/coating/assembly/forming, etc. In recent years, the design of electronic products has become thinner and lighter, screens have become larger, power consumption has increased,the charging speed has become faster and faster, and the shrinking of space has imposed higher and higher energy density requirements on lithium. Lithium batteries need to be constantly updated. To meet everyone's needs, batteries are evolving in the direction of small, light and thin. Topics related to lithium batteries have always been a hot research topic. scientific research groups and industrialized lithium batteries, such as laboratory active material charging, are still about 80%, while industrial batteries can already reach 95% or even more, there is not much research on battery auxiliary materials in the laboratory, resulting in the non-use of suitable materials, which affects battery performance; Battery materials and processes vary widely.
Lithium batteries have the cafollowing characteristics:
1. Have a higher weight-to-energy ratio and volume-to-energy ratio; , single-cell lithium battery The voltage is 3.6V, which is equal to the series voltage of three nickel-cadmium or nickel-metal hydride rechargeable batteries;
3. It has low self-discharge and can be stored for a long time, which is the most important advantage of this battery;
4. Lithium batteries do not have the so-called memory effect of nickel-cadmium batteries, so lithium batteries do not need to be discharged before being charged;
5. Long life expectancy. Under normal working conditions, the number of charge/discharge cycles of lithium batteries is more than 500 times;
6. Lithium batteries can generally be charged with a current of 0.5 to 1 times the capacity, reducing the charging time to 1 to 2 hours
7. They can be usedin parallel at will
<; p>8. Due to the fact that it does not contain heavy metal elements such as cadmium, lead and mercury, and does not pollute the environment, it is the most advanced green battery in the world; . High cost. Compared to other rechargeable batteries, lithium batteries are more expensive.With the rapid development of technology, in the near future, the lithium-ion battery you use may be so transparent that it cannot be seen. Our screen can become an additional battery when exposed to the sun. device and never have to deal with the embarrassment of a low battery again!