Introduction to lithium ion batteries
Lithium-ion batteries are secondary (rechargeable) batteries that rely on the movement of lithium ions between the positive and negative electrodes.In the process of discharge, Li ⁺ embedded back and forth between the two electrodes and embedded off;When charged, Li + falls from the positive pole and is embedded in the negative pole via an electrolyte. The anode is in a state rich in lithium;Television is the opposite.Lithium ion battery has a broad application prospect, which is mainly used in mobile phones and laptop computers, and is the representative of modern high-performance battery.
Lithium polymer batteries are different from lithium ion batteries
The anode and cathode materials used in polymer lithium ion batteries are the same as liquid lithium ions. The anode materials are divided into lithium cobalt acid, lithium manganese acid, ternary materials and lithium iron phosphate materials, and the cathode graphite. The working principle of the battery is basically the same.
The main difference is in electrolytes. Liquid lithium-ion batteries use liquid electrolytes, while polymer lithium-ion batteries use solid polymer electrolytes, which can be "dry" or "colloidal".
Lithium polymer batteries and lithium ion batteries which good
Lithium polymer batteries are good.
Lithium polymer battery is the upgrade product of lithium ion battery.Compared with the popular lithium-ion batteries, they have the advantages of large capacity, small size (thin) and safety (no explosion).However, due to the upgrading of the whole industrial chain takes some time, its cost is still relatively high at present, and it is only used in high-end digital products (ultra-thin laptop, etc.).
The advantages of lithium polymer battery mainly include the following aspects:
1. The working voltage of single lithium polymer battery is as high as 3, 6v~3 and 8v, which is much higher than the voltage of 1 and 2V of nickel metal hydride and nickel-cadmium battery.
2, lithium polymer battery capacity density, the capacity density is 1, 5~2, 5 times of nickel metal hydride battery or nickel cadmium battery, or higher.
3, lithium polymer battery self-discharge is small, after being placed for a long time, its capacity loss is small.
4, lithium polymer battery life is long, the normal use of its cycle life can reach more than 500 times.
5, lithium polymer battery has no memory effect, before charging will not necessarily empty the remaining power, easy to use.
6. Good safety performance
Polymer lithium batteries in the structure of the aluminum and plastic flexible packaging, different from the metal shell of the liquid battery, once a safety hazard occurs, the liquid battery is prone to explosion, and the polymer battery will only gas drum at most.
7, small thickness, can be made thinner
Lithium-polymer batteries are so thin that they can be assembled into credit CARDS.Ordinary liquid lithium battery adopts the method of customizing the shell first, and then plugging the anode and cathode materials. There is a technical bottleneck when the thickness is less than 3 or 6mm, while there is no such problem with the polymer battery. The thickness can be less than 1mm, which is in line with the current direction of mobile phone demand.
8. Light weight
Lithium-polymer batteries that use polymer electrolytes do not need metal shells as protective packaging.Polymer batteries are 40% lighter than steel - based lithium batteries of the same capacity and 20% lighter than aluminum - based batteries.
9. Large capacity
Polymer lithium battery is 10 ~ 15% higher than the steel shell battery capacity of the same size specification, 5 ~ 10% higher than the aluminum shell battery, become the first choice of color screen mobile phone and MMS mobile phone, the new color screen and MMS mobile phone on the market is also mostly used polymer battery.
10, small internal resistance
Polymer lithium battery internal resistance of batteries is less than liquid batteries, the current domestic internal resistance of the polymer batteries can even do below 35 m Ω, greatly reduced the battery power consumption, extend the standby time of mobile phone, can reach with international level.This kind of polymer lithium battery, which supports large discharge current, is an ideal choice for remote control model and has become the most promising product to replace nickel metal hydride battery.
11. Shape can be customized
Manufacturers are not limited to standard shapes, but can be economically made to the right size.Polymer lithium battery can increase or reduce the thickness of the battery according to customer demand, develop new battery models, the price is cheap, the mold cycle is short, and some can even be customized according to the shape of the phone, to make full use of the battery shell space, improve the battery capacity.
12. Good discharge performance
Polymer lithium battery USES colloidal electrolyte, compared with liquid electrolyte, colloidal electrolyte has stable discharge characteristics and higher discharge platform.
13. Simple design of protection plate
Due to the use of polymer materials, polymer lithium battery cells do not fire, do not explode, the battery itself has enough safety, so polymer battery protection circuit design can consider to omit PTC and fuse, so as to save battery cost.