Polymer lithium batteries generally refer to lithium polymer batteries. Lithium polymer batteries, also known as high-molecular lithium batteries, are a type of chemical battery. Compared to previous batteries, they feature high energy density, miniaturization, and lightweight design.
Lithium polymer batteries use a lithium alloy as the positive electrode and conductive polymer materials, polyacetylene, polyaniline, or poly(p-phenol) as the negative electrode, with an organic solvent as the electrolyte. Lithium-polyaniline batteries can achieve a specific energy of 350 W·h/kg, but a specific power of only 50-60 W/kg. They operate at temperatures ranging from -40 to 70 degrees Celsius and have a lifespan of approximately 330 cycles.
Compared to lithium-ion batteries, lithium polymer batteries have the following characteristics:
1. It relatively improves the battery leakage problem, but does not completely solve it.
2. Can be made into thin batteries: with a capacity of 3.6V 250mAh, its thickness can be as thin as 0.5mm.
3. Batteries can be designed in various shapes.
4. Can be made into a single high-voltage cell: Liquid electrolyte batteries can only achieve high voltage by connecting several cells in series, while polymer batteries, since they do not contain liquid, can be made into multi-layer combinations within a single cell to achieve high voltage.
5. Discharge capacity is theoretically 10% higher than that of lithium-ion batteries of the same size.
Lithium polymer batteries have many advantages, such as high energy density, miniaturization, ultra-thinness, lightweight and high safety. They can be made into batteries of any shape and capacity to meet the needs of various products. Furthermore, they use aluminum-plastic packaging, so any internal problems can be immediately reflected through the outer packaging. Even if there is a safety hazard, they will not explode, but will only swell.
In polymer batteries, the electrolyte serves a dual function as both a separator and a liquid electrolyte: on the one hand, it acts like a separator to isolate the positive and negative electrode materials, preventing self-discharge and short circuits within the battery; on the other hand, it acts like a liquid electrolyte to conduct lithium ions between the positive and negative electrodes. Polymer electrolytes not only possess excellent conductivity but also exhibit the unique properties of polymer materials, such as light weight, good elasticity, and ease of film formation, aligning with the development trend of lightweight, safe, efficient, and environmentally friendly chemical power sources.
