The differences between lithium iron phosphate batteries, polymer lithium batteries and ternary lithium batteries. All applications such as battery life, charging and discharging of electric vehicles are inextricably linked to the performance of the battery. The most commonly used batteries on the market today are lithium iron phosphate batteries, lithium polymer batteries, and ternary lithium batteries. Each of the three batteries has its own characteristics.
1. Polymer lithium battery
Polymer lithium batteries generally refer to polymer lithium-ion batteries. The positive and negative electrode materials used in polymer lithium batteries are the same as liquid lithium ions. The positive electrode materials are divided into lithium cobalt oxide, lithium manganate, ternary materials and lithium iron phosphate materials. The negative electrode is graphite. The working principle of the battery is also basically the same. . The principle of polymer lithium battery is the same as that of liquid lithium. The main difference is that the electrolyte is different from liquid lithium. The main structure of a battery includes three elements: positive electrode, negative electrode and electrolyte. The so-called polymer lithium-ion battery means that at least one or more of the three main structures use polymer materials as the main battery system. In the polymer lithium-ion battery system currently developed, polymer materials are mainly used in the positive electrode and electrolyte.
Benefits of polymer lithium batteries:
1. The operating voltage of a single battery is as high as 3.6v~3.8v, which is much higher than the 1.2V voltage of nickel metal hydride and nickel cadmium batteries.
2. High capacity density, its capacity density is 1.5 to 2.5 times that of nickel metal hydride batteries or nickel cadmium batteries, or perhaps higher.
3. The self-discharge is small and the capacity loss is very small after being left for a long time.
4. Long life, its cycle life can reach more than 500 times under normal use.
5. There is no memory effect, and there is no need to drain the remaining power before charging, making it easy to use.
6. With good safety performance, polymer lithium batteries use aluminum-plastic soft packaging in structure, which is different from the metal casing of liquid batteries. Once a safety hazard occurs, liquid batteries are easy to explode, while polymer batteries will only Air drum.
7. The thickness is small and can be made thinner. Ultra-thin, the battery can be built into a credit card. Ordinary liquid lithium batteries adopt the method of customizing the casing first and then plugging the positive and negative electrode materials. There is a technical bottleneck when the thickness is less than 3.6mm. This problem does not exist with polymer batteries. The thickness can be less than 1mm, which is in line with the current mobile phone Mitsubishi Chemical. Resin demand direction.
8. Light weight, batteries using polymer electrolytes do not require a metal shell as a protective outer packaging. Polymer batteries are 40% lighter than standard steel-cased lithium batteries of the same capacity and 20% lighter than aluminum-cased batteries.
9. Large capacity. Polymer batteries have a capacity 10-15% higher than steel-shell batteries of the same standard and 5-10% higher than aluminum-shell batteries. They have become the first choice for color screen mobile phones and MMS mobile phones. Now there are new ones on the market. Most of the color screen and MMS mobile phones use polymer batteries.
10. Small internal resistance
The internal resistance of polymer batteries is smaller than that of ordinary liquid batteries. Now the internal resistance of domestic polymer batteries can even be below 35mΩ, which greatly reduces the battery’s self-consumption and extends the standby time of mobile phones. It can fully reach the level of international standards. This kind of polymer lithium battery that supports large discharge current is an ideal choice for remote control models and has become the most promising product to replace nickel-metal hydride batteries.
11. The shape can be customized
Manufacturers are not limited to standard shapes and can be economically made into suitable sizes. Polymer lithium batteries can be added or reduced according to customer needs, and new cell types can be developed. They are cheap and have a short mold opening cycle. Some can even be customized according to the shape of mobile phones to make full use of the battery casing space and improve the quality of the battery. battery capacity.
12. Simple protection board design
Due to the use of polymer materials, the battery core does not catch fire or explode, and the battery core itself has sufficient safety. Therefore, the protection circuit design of polymer batteries can consider omitting PTC and fuses, thereby saving battery costs.
2. Lithium iron phosphate battery
Lithium iron phosphate battery refers to a lithium-ion battery using lithium iron phosphate as the cathode material. The cathode materials of lithium batteries mainly include lithium cobalt oxide, lithium manganate, lithium nickel oxide, ternary materials, lithium iron phosphate, etc. Among them, lithium cobalt oxide is the cathode material used in most lithium-ion batteries today. Regarding the cathode material of LiFePO4, its material sources are relatively wide, the number of cycles is long, the safety index is also high, it has less environmental pollution, and it shows very strong comprehensive functions in many cathode materials.
When LiFePO4 lithium iron phosphate battery is charging, the lithium ions Li in the positive electrode move to the negative electrode through the polymer separator; during the discharge process, the lithium ions Li in the negative electrode move to the positive electrode through the separator. Lithium-ion batteries are named because lithium ions move back and forth during charging and discharging.
Benefits of lithium iron phosphate batteries:
1. Lithium iron phosphate batteries have a long life and the number of cycles is more than 2,000 times. Under the same conditions, lithium iron phosphate batteries can be used for 7 to 8 years.
2. Use safely. Lithium iron phosphate batteries have undergone rigorousThe safety inspection ensures that no explosion will occur even in a traffic accident.
3. Fast charging. Using a special charger, the battery can be fully charged at 1.5C in 40 minutes.
4. Lithium iron phosphate batteries are resistant to high temperatures, and the hot air value of lithium iron phosphate batteries can reach 350 to 500 degrees Celsius.
5. Lithium iron phosphate battery has a large capacity.
6. Lithium iron phosphate batteries have no memory effect.
7. Lithium iron phosphate battery ACE liquid calcium zinc pool is green, environmentally friendly, non-toxic, non-polluting, has wide sources of raw materials and is cheap.
Three, ternary lithium battery
Ternary lithium battery refers to a lithium battery that uses lithium nickel cobalt manganate as the positive electrode material and graphite as the negative electrode material. Unlike lithium iron phosphate, ternary lithium batteries have a high voltage, which means that under the same volume or weight, ternary lithium batteries have greater specific energy and specific power. In addition, ternary lithium batteries also have great advantages in terms of high-rate charging and low-temperature resistance. Compared with lithium iron phosphate batteries, ternary lithium batteries are more suitable for current and future household electric vehicles.
Ternary lithium batteries have better low-temperature resistance and are the main technical process for manufacturing low-temperature lithium batteries. At minus 20°C, ternary lithium batteries can release 70.14% of their capacity, while lithium iron phosphate batteries can only release 54.94% of their capacity. % capacity, and because under low temperature conditions, the discharge path of ternary lithium batteries is much higher than the voltage path of lithium iron phosphate batteries and starts faster.
Lithium iron phosphate batteries are better than ternary lithium batteries. The theoretical cycle number of ternary lithium batteries is 2,000 times, but basically at 1,000 cycles, the capacity decays to 60%; even the best brand in the industry, Tesla , it can only maintain 70% of its power after 3,000 times, while lithium iron phosphate batteries still have 80% of their capacity after the same cycle.
The above are the differences between lithium iron phosphate batteries, polymer lithium batteries, and ternary lithium batteries. As for which battery to choose, you still need to compare it yourself and choose the appropriate lithium battery according to the actual situation.
