Polymer batteries are good.
Lithium polymer batteries are an upgraded replacement for lithium-ion batteries. Compared to the currently popular lithium-ion batteries, they have advantages such as larger capacity, smaller (thinner) size, and safety (no explosion). However, because the entire industry chain requires a certain amount of time to upgrade, their manufacturing cost is currently relatively high, and they are only used in high-end digital products (such as ultra-thin laptops).
The advantages of polymer lithium batteries are mainly as follows:
1. The working voltage of a single cell 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, which is 1.5 to 2.5 times or higher than that of nickel-metal hydride or nickel-cadmium batteries.
3. It has low self-discharge and minimal capacity loss even after prolonged storage.
4. Long lifespan; under normal use, its cycle life can reach more than 500 times.
5. It has no memory effect, so there is no need to completely discharge the remaining power before charging, making it convenient to use.
6. Good safety performance
Polymer lithium batteries use aluminum-plastic soft packaging, unlike the metal casing of liquid cells. In the event of a safety hazard, liquid cells are prone to explosion, while polymer cells will at most bulge.
7. It has a small thickness, allowing it to be made even thinner.
Ultra-thin, the battery can be assembled into a credit card. Conventional liquid lithium batteries use a method of first customizing the casing and then filling in the positive and negative electrode materials, which has a technical bottleneck in achieving a thickness of less than 3.6mm. Polymer cells do not have this problem, and the thickness can be less than 1mm, which meets the current demand for mobile phones.
8. Lightweight
Batteries using polymer electrolytes do not require a metal casing for protection. Polymer batteries are 40% lighter than steel-cased lithium batteries of the same capacity and 20% lighter than aluminum-cased batteries.
9. Large capacity
Polymer batteries have 10-15% higher capacity than steel-cased batteries of the same size and 5-10% higher capacity than aluminum-cased batteries, making them the preferred choice for color screen and MMS phones. Most new color screen and MMS phones on the market now use polymer batteries.
10. Low internal resistance
Polymer cells have lower internal resistance than conventional liquid cells. Currently, domestically produced polymer cells can even achieve internal resistance below 35mΩ, significantly reducing battery self-discharge and extending mobile phone standby time, 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.
11. Shape can be customized
Manufacturers are not limited to standard shapes and can economically produce batteries of suitable sizes. Polymer batteries can increase or decrease cell thickness according to customer needs, develop new cell models, are inexpensive, have short mold-making cycles, 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.
12. Excellent discharge characteristics
Polymer batteries use gel electrolytes, which have more stable discharge characteristics and a higher discharge plateau compared to liquid electrolytes.
13. The protection board has a simple design.
Because polymer materials are used, the battery cells do not catch fire or explode, and the cells themselves have sufficient safety. Therefore, the protection circuit design of polymer batteries can omit PTC and fuses, thereby saving battery costs.
Lithium-ion batteries are rechargeable batteries that primarily function by the movement of lithium ions between the positive and negative electrodes. During discharge, Li⁻ ions repeatedly insert and extract between the two electrodes; during charging, Li⁻ detaches from the positive electrode, passes through the electrolyte, and inserts into the negative electrode, leaving the negative electrode in a lithium-rich state; the reverse occurs during charging. Lithium-ion batteries have a wide range of applications and are currently mainly used in mobile phones and laptops, representing the pinnacle of modern high-performance batteries.
Polymer lithium batteries: Based on the different electrolyte materials used, lithium-ion batteries are divided into liquid lithium-ion batteries (LIB) and polymer lithium-ion batteries (PLB) or plastic lithium-ion batteries (PLB). The positive and negative electrode materials used in polymer lithium-ion batteries are the same as those in liquid lithium-ion batteries: positive electrode materials include lithium cobalt oxide, lithium manganese oxide, ternary materials, and lithium iron phosphate; the negative electrode is graphite. The working principle is also basically the same. Their main difference lies in the electrolyte. Liquid lithium-ion batteries use a liquid electrolyte, while polymer lithium-ion batteries use a solid polymer electrolyte. This polymer can be in a "dry" state or a "gel" state; currently, most use polymer gel electrolytes.
