Lithium-polymer Li-pol batteries and batteries differ from conventional lithium-ion batteries in the type of electrolyte used. Developed in the 1970s, they use only solid, dry polymer electrolyte. It looks like a plastic film that does not conduct electric current, but provides ion exchange. That is, ions passing through itself – electrically charged atoms or groups of atoms.
Lithium-polymer Li-pol batteries, description, features of the device and design, application, main advantages and disadvantages.
Polymer electrolyte replaces the traditional porous separator impregnated with liquid electrolyte. Dry polymer can simplify production, improve the safety of batteries of this type and achieve their thin-profile geometry. This eliminates the risk of ignition of the batteries, since they do not use liquid or gel electrolyte.
With the advent of lithium-polymer battery cells with a thickness of only 1 mm, equipment designers have opened up new possibilities regarding the final shape and size of new electronic devices. Many restrictions were lifted regarding the micro-miniaturization of electronic devices. New micronutrients for commercial use appeared on the market relatively recently.
Unfortunately, the disadvantage of lithium polymers is their poor conductivity. The internal resistance of lithium-polymer batteries is too large and does not allow to provide the currents necessary for the operation of modern communications and the hard drives of laptop computers. Although heating an element of such batteries to 60 degrees and above increases the conductivity to the required values, this method of reducing their internal resistance is not always suitable for commercial applications.
Research in the field of improving the characteristics of lithium-polymer batteries when operating at temperatures close to room temperature is ongoing. It is expected that lithium-polymer Li-pol batteries will appear capable of maintaining operability when the number of charge / discharge cycles up to 1000 and having a higher energy density than the lithium-ion batteries and batteries currently manufactured.
At the same time, lithium-polymer batteries are currently successfully used in backup power sources in countries with hot climates. Most often, they replace Lead Acid Batteries (VRLA), which are critical for high temperature applications..
Lithium-ion and lithium-polymer gel electrolyte batteries, what is the difference between them.
Sometimes, to reduce the internal resistance of lithium-polymer batteries, they use an addition of gel electrolyte. Most lithium polymer batteries used to power mobile phones are actually hybrid. They are a cross between lithium-ion and lithium-polymer batteries, and they use a gel electrolyte. The correct name for such batteries is lithium-ion polymer batteries. Although for promotional purposes, many manufacturers call them lithium-polymer.
What is the difference between lithium-ion and lithium-polymer gel electrolyte batteries? Although their characteristics are close, in lithium-polymer batteries, solid electrolyte is used instead of separators. The gel electrolyte added to them is intended simply to improve ion-exchange processes. Thus reducing internal resistance.
Technical difficulties in the production of lithium-ion polymer batteries slow down their market advancement. And investors are always quicker to get a return on money invested in research..
Currently, all the potential benefits of lithium polymer batteries have not yet been realized. Not achieved their higher capacity. It is still less than the capacity of lithium-ion batteries. Their production is more expensive than the production of the same lithium-ion batteries..
However, due to the possibility of a significant reduction in the thickness of lithium-polymer batteries, interest in them, especially mobile phone manufacturers, has not disappeared. The design of cases for such batteries is simpler; foil is required for their production, which is used in the food industry.
The advantages of lithium-ion polymer batteries and batteries:
Very small thickness. Comparable to the thickness of a credit card.
Flexible form factor. Manufacturers do not have to be attached to any standard sizes. Lithium Polymer Li-pol batteries can be manufactured in any reasonable size and shape..
Light weight. Gel electrolyte is much lighter than liquid; its use allows to simplify the design of the casing and abandon the metal shell of the cell casing.
Better operation safety. Lithium-polymer Li-pol batteries are overcharge resistant, they cannot leak electrolyte.
Disadvantages of lithium-ion polymer batteries and batteries:
Lower energy density and lower life compared to lithium-ion batteries. Although the possibilities for their improvement are far from exhausted..
The high cost of production. However, with mass production, prices for lithium-polymer Li-pol batteries will drop.
Based on the book Battery.