Advantages and disadvantages of Polymer Lithium-Ion Battery

Advantages and disadvantages of Polymer Lithium-Ion Battery 

Polymer Lithium-Ion Battery ( Lipo battery ) are made of the materials as liquid lithium ions, the cathode material is composed of lithium cobalt, lithium manganese, ternary and lithium iron phosphate. The anode material is graphite. 

1. The voltage of single cell is 3.7 V, which is much higher than 1.2 V of NIMH and LiMNO2 Battery. 

2. Capacity density is large, its capacity density is 1.5 ~ 2.5 times than NIMH battery or NICD Battery , or higher. 

3. The self-discharge is small, and the capacity loss is small after a long time. 

4. Long life, the normal use of its cycle life can reach more than 500 times. 

5. No memory effect, no need to empty the remaining power before charging, easy to use. 

6. High safety polymer lithium-ion battery  ( Lipo battery ) are constructed in aluminum-plastic flexible packaging, which is different from the metal shell of a liquid battery. The liquid battery is prone to explosion in case of safety problems, while the polymer battery can only inflate at most. 

7. It's thin, it can be made thinner and thinner, ultra thin battery, and the battery can be assembled into a credit card. The conventional lithium battery adopts the method of custom-made outer shell and back plug of positive and negative electrode material. The thickness can be below 1 mm, in line with the direction of demand for many products. 

8. Light weight. batteries using polymer electrolytes do not require a metal shell for protective packaging. The weight of the polymer battery is 40% lighter than that of the lithium battery of the same capacity, and 20% lighter than that of the aluminum battery, LiSOCL2 battery.

9. The large capacity polymer battery is 10-15% higher than the same size steel shell battery and 5-10% higher than the aluminum shell battery. It is the first choice for mobile phone, most of the new color screens and MMS mobile phones on the market now also use polymer cells. 

10. The internal resistance of a small polymer cell is smaller than that of a normal liquid cell. At present, the internal resistance of a domestic polymer cell can even be less than 35m, greatly reducing the self-consumption of the battery and prolonging the standby time of the cell phone, it can reach the level of international integration. The polymer lithium battery, which supports large discharge current, is an ideal choice for remote control models and is the most promising alternative to ni-mh batteries. 

11. Shape can be customized according to customer needs to add or reduce cell thickness, size, development of new cell models, cheap, die-opening cycle short, and even tailored to the shape of the phone, in order to make full use of the battery shell space, enhance the battery capacity. 

12. Compared with the liquid electrolyte, the colloid electrolyte has the stable discharge characteristic and the higher discharge platform. 

13. Protection Plate design is simple due to the use of polymer materials, the core does not fire, do not explode, the core itself has enough safety, therefore, the polymer battery protection circuit design can consider omitting PTC and Fuse, thus saving the cost of batteries.

Remarks: 

Pay more attention on short circuit polymer lithium-ion battery ( Lipo battery ). Including: Internal Short Circuit, external short circuit and so on. As a result, most of today's lithium-ion battery come with PCM that protect against short circuits. 

Do not overcharge the polymer lithium-ion battery. If the charge time is too long, the possibility of expansion will increase. The lithium chemical property is very active and easy to burn. When the battery is charged and discharged, the internal temperature of the battery continues to rise. The gas generated in the process of activation expands, and the internal pressure of the battery increases to a certain extent, if the case is damaged, it will break, causing leakage, fire and even explosion, such as steel lithium-ion batteries, while polymer lithium-ion battery will only expand.