Polymer batteries are the third generation of lithium-ion batteries, developed from traditional steel-cased and aluminum-cased batteries. Their lighter weight, thinner profile, and higher energy density have made them popular with domestic and international communication terminal manufacturers and design companies. The most fundamental difference between polymer lithium-ion batteries and liquid lithium-ion batteries lies in the electrolytes they use. So, how long is the lifespan of polymer lithium-ion batteries? What are their advantages?
How long is the lifespan of polymer lithium-ion batteries?
Lithium-ion batteries are classified into two types: polymer lithium-ion batteries and liquid lithium-ion batteries. Polymer lithium-ion batteries and liquid lithium-ion batteries use the same positive and negative electrode materials and have similar working principles, but their electrolytes differ. Polymer lithium-ion batteries are lightweight, have high energy storage capacity, good discharge performance, can be manufactured in various shapes, and have a long lifespan.
Under internationally unified standards, battery life is not expressed in terms of time, but rather in terms of the number of cycles, which is the total number of complete discharges. Typical lithium-ion batteries have a lifespan of 500 to 800 cycles, while Grade A polymer batteries can reach 800 cycles. Therefore, choosing a reputable battery supplier ensures battery quality and a longer lifespan.
The lifespan of polymer batteries is highly dependent on their performance. Polymer lithium-ion batteries, also known as polymer batteries, have an aluminum-plastic casing, unlike the metal casing of liquid lithium-ion batteries. The reason for using an aluminum-plastic casing is that polymer batteries utilize colloidal substances to help the battery plates adhere and absorb the electrolyte, thus significantly reducing the amount of liquid electrolyte used.
Structural improvements give polymer batteries advantages such as high energy density, smaller size, and ultra-thin design. Compared to liquid lithium-ion batteries, polymer batteries have a longer lifespan, reaching at least 500 cycles. However, the lifespan of polymer lithium-ion batteries will also decrease if they are not charged for an extended period. Polymer lithium-ion batteries achieve their ideal lifespan only when electrons are continuously flowing.
The lifespan of lithium polymer batteries differs between theory and practice, but their structural characteristics give them a significant advantage over traditional batteries. To address the factors affecting the lifespan of polymer batteries in practical applications, one can focus on shallow charging and discharging, appropriate voltage, and suitable storage temperature to extend the lifespan of polymer lithium-ion batteries.
Currently, polymer lithium-ion batteries are priced higher than liquid lithium-ion batteries. Compared to liquid lithium-ion batteries, they have a longer lifespan and better safety performance, and are expected to see significant price increases in the near future.
Advantages of polymer lithium-ion batteries
Polymer lithium-ion batteries not only offer high safety but also boast advantages such as thinness, versatility in area and shape, and a lighter aluminum-plastic composite film for the casing. However, their low-temperature discharge performance may still have room for improvement.
1. Good safety performance: Polymer lithium-ion batteries use aluminum-plastic soft packaging in their structure, which is different from the metal shell of liquid cells. In the event of a safety hazard, liquid cells are prone to explosion, while polymer cells will at most bulge.
2. Thinner and thinner: Liquid lithium batteries typically use a custom-designed casing followed by the filling of positive and negative electrode materials, which presents a technical bottleneck in achieving a thickness of less than 3.6mm. Polymer cells, on the other hand, do not have this problem and can achieve a thickness of less than 1mm, which meets the current demand for mobile phones.
3. Lightweight: Polymer lithium-ion batteries are 40% lighter than steel-cased lithium batteries of the same capacity and 20% lighter than aluminum-cased batteries.
4. Large capacity: Polymer batteries have a 10-15% higher capacity than steel-cased batteries of the same size and a 5-10% higher capacity than aluminum-cased batteries, making them the preferred choice for color screen and MMS phones. Most of the new color screen and MMS phones on the market today also use polymer cells.
5. Low internal resistance: Polymer cells have lower internal resistance than conventional liquid cells. Currently, the internal resistance of domestically produced polymer cells can even be below 35mΩ, greatly reducing battery self-discharge and extending the standby time of mobile phones, fully meeting international standards. This type of polymer lithium battery, which supports high discharge current, is also an ideal choice for remote control models, becoming the most promising replacement for nickel-metal hydride batteries.
6. Customizable shape: Polymer lithium-ion batteries can have their cell thickness increased or decreased according to customer needs, and new cell models can be developed. They are inexpensive, have a short mold opening cycle, and some can even be custom-made to fit the shape of a mobile phone to make full use of the battery casing space and increase battery capacity.
As a type of lithium-ion battery, polymer batteries have several advantages over liquid lithium-ion batteries, including higher density, smaller size, thinner profile, and lighter weight. At the same time, polymer lithium-ion batteries also have significant advantages in terms of safety and cost utilization, making them a widely recognized new energy battery in the industry.
