The main difference between lithium-ion polymer batteries lies in the electrolyte. Liquid lithium-ion batteries use liquid electrolytes, while polymer lithium-ion batteries use solid polymer electrolytes instead. This polymer can be "dry" or "gel-like," but most currently use polymer gel electrolytes.
I. Classification of Lithium-ion Polymer Batteries
1. Solid polymer electrolyte lithium-ion battery: The electrolyte of a solid polymer electrolyte lithium-ion battery is a mixture of polymer and salt. This type of battery has low ionic conductivity at room temperature and can be used at room temperature.
2. Gel polymer electrolyte lithium-ion battery: Gel polymer electrolyte lithium-ion battery is made by adding plasticizers and other additives to a solid polymer electrolyte, thereby improving the ionic conductivity and allowing the battery to be used at room temperature.
3. Polymer Lithium-ion Batteries: Lithium-ion batteries using polymer cathode materials employ conductive polymers as the cathode material, resulting in a relatively increased specific capacity. Because a solid electrolyte replaces the liquid electrolyte, polymer lithium-ion batteries offer advantages over liquid lithium-ion batteries, including thinner profiles, arbitrary area, and arbitrary shape. Therefore, aluminum-plastic composite films can be used to manufacture the battery casing, further improving the overall specific capacity. Polymer lithium-ion batteries can also use polymers as the cathode material, increasing their specific energy by more than 20% compared to current liquid lithium-ion batteries. Polymer lithium-ion batteries are characterized by miniaturization, thinness, and lightweight design. Therefore, polymer batteries are expected to gradually gain a larger market share.
II. Precautions for using lithium-ion polymer batteries
1. Pay attention to short circuit situations
Polymer lithium-ion batteries are prone to short circuits during charging, including internal and external short circuits. Although most lithium-ion batteries now come with short-circuit protection circuits and explosion-proof wires, these protection circuits may not function under various circumstances, and the explosion-proof wires offer limited protection.
2. Do not overcharge.
Polymer lithium-ion batteries are more prone to expansion if charged for too long. Lithium is chemically very reactive and easily combustible. During charging and discharging, the battery's internal temperature continuously rises, and the gases produced during activation expand, increasing the internal pressure. If the pressure reaches a certain level, and the casing is damaged, the battery can rupture, causing leakage, fire, or even explosion. Polymer lithium-ion batteries, however, will only expand.
When using lithium-ion polymer batteries, everyone must pay attention to safety.
