Characteristics and Safety of 18650 Battery.

Characteristics and Safety of 18650 Battery.

18650 lithium battery production requires protective circuits to prevent the battery from being overcharged or discharged. Of course, this is necessary for lithium batteries, and it is also a common disadvantage of lithium batteries, because the materials used in lithium batteries are mostly lithium cobalt oxide materials, and lithium cobalt oxide materials cannot discharge high currents and have poor safety. From a classification perspective, 

18650 lithium batteries can be classified in the following way.

1. Classified by practical performance of batteries
Power type batteries and energy type batteries. Energy type batteries are characterized by high energy density and are mainly used for high-energy output; Power type batteries are characterized by high power density and are mainly used for instantaneous high-power output and output batteries. The power energy type lithium battery emerged with the emergence of plug-in hybrid vehicles. It requires a high amount of energy stored in the battery, which can support pure electric driving for a certain distance, and also has good power characteristics to enter hybrid mode when the battery is low.

Simply put, the energy type is similar to a marathon runner. To have endurance, high capacity is required, and high current discharge performance is not required; So the power type is a sprinter who strives for explosive power, but also needs endurance, otherwise if the capacity is too small, they won't be able to run far.

2. Classified by electrolyte material
Lithium ion batteries are divided into liquid lithium-ion batteries (LIB) and polymer lithium-ion batteries (PLB).

Liquid lithium-ion batteries use liquid electrolytes (currently most power batteries use this type). Polymer lithium ion batteries are replaced by solid polymer electrolytes, which can be either "dry" or "colloidal". At present, most of them use polymer gel electrolytes. Regarding solid-state batteries, strictly speaking, it refers to both electrodes and electrolytes being solid.

3. Classified by product appearance
Cylindrical and square outer packaging are mostly made of steel or aluminum shells. The outer packaging of the soft pack is made of aluminum-plastic film. In fact, the soft pack is also a square shape. It is commonly referred to as a soft pack in the market when packaged with aluminum-plastic film. Some people also refer to soft pack batteries as polymer batteries.
For cylindrical lithium-ion batteries, the model number is generally a 5-digit number. The first two digits are the diameter of the battery, and the middle two digits are the height of the battery. The unit is millimeters. For example, the 18650 lithium battery has a diameter of 18 millimeters and a height of 65 millimeters.