Advantages and Disadvantages of Lithium Polymer Batteries

Lithium polymer batteries are a type of lithium-ion battery, but compared to liquid lithium batteries (Li-ion), they have many significant advantages, such as higher energy density, smaller size, ultra-thin form, lighter weight, higher safety, and lower cost. They are a new generation of batteries. Below we will detail the advantages and disadvantages of lithium polymer batteries.

Lithium Polymer Batteries

I. Advantages:

Good Safety Performance
Lithium polymer batteries use aluminum-plastic soft packaging, unlike the metal casing used for liquid lithium cells. If there is a safety issue, liquid lithium cells are more likely to explode, while polymer cells will only puff up at most.

Thin and Can Be Made Thinner
These batteries are ultra-thin and can even be assembled into the size of a credit card. Standard liquid lithium batteries require custom casings and then insertion of the positive and negative materials, with a thickness limit of 3.6mm. However, polymer cells do not face this issue and can be made thinner, with thicknesses under 1mm, meeting the current needs for smartphones.

Light Weight
Lithium polymer batteries use a polymer electrolyte, which does not need a metal shell for protection. These batteries are 40% lighter than steel-cased lithium batteries of the same capacity and 20% lighter than aluminum-cased batteries.

Large Capacity
Polymer batteries have a 10-15% higher capacity than steel-cased lithium batteries of the same size and 5-10% higher than aluminum-cased batteries. They are the preferred choice for color screen and MMS phones, and most of the new color screen and MMS phones on the market now use polymer batteries.

Low Internal Resistance
Polymer cells have lower internal resistance than general liquid lithium cells. Currently, some domestic polymer cells can have an internal resistance of less than 35mΩ, greatly reducing the self-discharge rate and extending the standby time of mobile phones, reaching international standards. These polymer lithium batteries, which support large discharge currents, are also ideal for remote-controlled models, making them the most promising product to replace nickel-metal hydride batteries.

Customizable Shape
Manufacturers are not limited to standard shapes, allowing for the economical production of batteries in the appropriate size. Polymer batteries can be customized to increase or decrease the thickness of the cell according to customer needs, and new cell models can be developed. They are inexpensive, have short mold development cycles, and can even be tailored to fit the shape of a phone, fully utilizing the space inside the battery casing to increase the battery’s capacity.

Good Discharge Characteristics
Polymer batteries use gel electrolytes, which, compared to liquid electrolytes, provide stable discharge characteristics and a higher discharge platform.

Simpler Protection Circuit Design
Due to the use of polymer materials, the cells are fireproof and explosion-proof, offering sufficient safety. As a result, the protection circuit design for polymer batteries can omit the PTC and fuses, reducing battery costs.

II. Disadvantages:

Compared to lithium-ion batteries, lithium polymer batteries have lower energy density and fewer charge cycles.

They are expensive to manufacture.

There is no standard shape, and most batteries are designed for the high-capacity consumer market.

Compared to lithium-ion batteries, the price and energy density are higher.