Rechargeable lithium-ion batteries have a variety of configurations, physical sizes and capacity levels. There are three basic configurations for the lithium chemical industry.
The first is a circular configuration similar to a small barrel, called a cylindrical battery/battery. Typical dimensions are 18×65 mm, 21×50 mm and 26×65 mm.
The second common configuration is flat and rectangular, similar to a small box called a prismatic battery. Typical sizes are 5×34×50 mm and 10×34×50 mm, as well as various other standard sizes.
The third configuration is a flat foil bag, very similar to a chewing gum package, and is commonly referred to as a lithium polymer battery/battery. The typical size is each prismatic unit, but there are various additional sizes on the market.
Industrial terms typically refer to cylindrical and prismatic batteries as traditional lithium ion batteries and pouch batteries, as lithium polymer or lithium polymer or pouch batteries. For the purpose of this article, we will use lithium ion traditional batteries and lithium polymer as the bag nomenclature.
Compare from manufacturing cost
Traditional lithium ion and lithium polymer manufacturing are very different. Regarding lithium-ion batteries, a large number of expensive automation equipment and tools are required to produce batteries. Cylindrical battery configuration has become the main force in the industry and has become the most commonly used configuration in various applications. As the rechargeable lithium chemistry technology matures, this is also the most advanced technology.
The manufacturing of prismatic batteries also requires intensive capital equipment expenditures. However, technological progress in the field of prismatic batteries/batteries has become less and less. From a manufacturing point of view, the manufacturing cost of cylindrical batteries is the lowest, followed by the prism configuration.
This is different from the case of Li Duo cells. As a pouch battery, the manufacturing cost of tools and equipment is low. The overall investment cost of establishing the battery assembly process is also low. Manufacturing lithium polymer foil bags is much more intensive than traditional lithium ion can batteries. Moreover, because the overall mold and equipment costs are much lower, designers can choose more bag unit sizes. The lithium polymer structure allows the manufacture of oddly shaped and even bendable batteries. The design and development of lithium polymer batteries will cover all internal spaces within a given battery case; this is equivalent to the maximum capacity that can be supplied in the battery pack.
From the chemical composition comparison
From a chemical point of view, traditional lithium ions are the same/similar to lithium polymers. Both have various formulas to improve life, energy density, safety and overall performance characteristics. All well-known lithium-ion battery and lithium-ion battery manufacturers have undergone a series of certification tests to confirm the safety of design and manufacturing. The meaning of these tests is UL1642 and UL62133. In these standards, the battery is subjected to short circuit, temperature shock, low pressure, abnormal charging, forced discharge, squeeze, shock, shock, vibration, heating and projectile tests.
However, with regard to Li-poly batteries, there is an abnormal compliance due to the foil bag configuration. In the absence of a metal structure, the specific requirements of extrusion, impact and projectiles are not considered. This does not mean that lithium polymers are not as safe as traditional lithium-ion products; it just means that current test methods cannot be applied to sachet products.
Since there is no supporting external structure around the internal active material, the configuration of the battery pack using the Li-poly battery must be different from the conventional Li ion. The battery must be fixed or assembled in a way that prevents movement inside the battery pack.
Traditional lithium-ion batteries use metal cans as the casing to provide external support. However, this sealed metal can can act as a pressure vessel under abuse conditions. Although the unit design usually includes a venting mechanism, the vents cannot always operate fast enough during catastrophic events to prevent the full rupture of the tank. Regarding Lipoly, the aluminum foil bag does not have an exhaust device, so it cannot contain internal pressure buildup. The seam of the bag will usually rupture and discharge any excessive pressure. Please refer to the table for a comparison between the two chemicals.
Since all the internal space (cylindrical voids) in the battery box (or plastic case) is not used, the use of cylindrical batteries may not provide the highest capacity. Depending on the real estate, prismatic and LiPoly batteries can sometimes use all the available internal space in the battery pack. Professional-sized LiPoly batteries can be manufactured to completely fill the internal space. From a weight point of view, due to the lighter weight of aluminum foil bags, traditional can-type batteries are heavier than lithium polymers in specific applications.
In terms of environmental issues, all lithium-ion batteries and lithium-ion batteries/batteries must be recycled properly and should be disposed of in the normal waste stream. As with any battery, it is recommended to encourage participation in a formal recycling program.
Are lithium polymer batteries a better choice?
Finally, lithium polymer batteries have several advantages over lithium ion batteries in portable applications:
The charging and discharging process is very safe, good system, and excellent thermal stability.
Light weight and high power density.
Better low temperature performance, limited voltage suppression and higher capacity delivery.
The manufacturing investment is less in a larger range of cell sizes.
Battery real estate is not limited to the size of industrial batteries specified for consumer use and device applications; that is, the battery shape is ideally suited to the device it will power.
The cycle life of commercial lithium-ion products is excellent.
The product cost in many applications is comparable to Li-ion, but this depends largely on the battery configuration and volume.
Due to the size, lighter weight, higher energy density, safety, consumer safety and flexible assembly into the device, the consumer market is ready to use more lithium ion batteries than lithium ion.
