14.8V 2200mAh 18650 Li ion Rechargeable Batteries

The 18650 lithium-ion battery must have a protective line to prevent the battery from being overcharged and discharged. , Of course, this is a must for lithium ion batteries, which is also a general disadvantage of lithium ion batteries, because the materials used are basic cobalt oxide lithium ion batteries, lithium and lithium cobalt oxide materials for lithium ion batteries cannot be discharged at large currents , Poor safety, from classification, classification 18650 lithium-ion batteries can be classified by the following methods.

1. Classification according to the actual performance of the battery

   Power batteries and energy batteries. Energy type batteries have the characteristics of high energy density and are mainly used for high energy output. Power type batteries have the characteristics of high power density and are mainly used for instantaneous high power output and output batteries. The electric lithium-ion battery is accompanied by the emergence of plug-in hybrid electric vehicles. It requires a large amount of energy stored in the battery, can support a range of pure electric drives, and has good power characteristics, entering hybrid mode when the battery is low.

   A simple understanding is that the energy type is similar to a marathon runner. To have endurance, it requires high capacity, and the high current discharge performance is not high; so the strength is a sprinter, and the battle is an explosion of strength, and endurance is also required, otherwise the ability is too small. can’t run far.
   
   

2. According to the electrolyte material

   Lithium-ion batteries are divided into liquid lithium-ion batteries (LIB) and polymer lithium-ion batteries (PLB).Liquid lithium-ion batteries use a liquid electrolyte (currently used in power lithium batteries). Lithium-ion polymer batteries are replaced by solid polymer electrolytes, which can be either dry or colloidal, most of which are currently polymer gel electrolytes. In a solid-state battery, both the electrodes and the electrolyte are solid.
   
   

3. Classification according to product appearance 

   Divided into: cylinder, softback, square.Steel or aluminium housings in cylindrical and square packages. The flexible packaging packaging is aluminum-plastic film. In fact, the flexible packaging is square. The aluminum-plastic film packaging commonly used in the market is called flexible packaging, and some people call it polymer battery.Regarding cylindrical lithium-ion batteries, the model number is usually 5 digits.The first two digits are the diameter of the battery, and the middle two digits are the height of the battery. It’s in mm. For example, an 18650 lithium-ion battery has a diameter of 18 mm and a height of 65 mm.

4. Classification by pole piece material 

   Cathode materials: Lithium Iron Phosphate (LFP), Lithium Cobalt Oxide (LCO), Lithium Manganese Oxide (LMO), (Binary Battery: Lithium Nickel Oxide / Lithium Nickel Nickel Oxide), (ternary Battery: Nickel oxide nickel manganese lithium-ion battery (NCM), nickel aluminate lithium-ion battery (NCA)).
   

The common faults and causes of lithium batteries are as follows:

• Low battery capacity 

  Causes: a. The amount of attached material is too small; b. The amount of attached material on both sides of the pole piece is quite different; c. The pole piece is broken; d. The electrolyte is less; e. The conductivity of the electrolyte is low; f. Not well prepared; g. The porosity of the diaphragm is small; h. The adhesive is aging → the attached material falls off; i. The winding core is too thick (not dried or the electrolyte is not penetrated) j. The volume is not fully charged; k. Positive and negative electrodes The material has a small specific capacity.

• High internal resistance of battery 

  Causes: a. Welding of negative electrode and tab; b. Welding of positive electrode and tab; c. Welding of positive electrode and cap; d. Welding of negative electrode and shell; e. Large contact resistance between rivet and pressure plate ; f. No conductive agent is added to the positive electrode; g. There is no lithium salt in the electrolyte; h. The battery has been short-circuited; i. The porosity of the separator paper is small.

  
  

• Low battery voltage 

  Causes: a. Side reactions (decomposition of electrolyte; impurities in the positive electrode; water); b. Not well-formed (SEI film is not formed safely); c. Customer’s circuit board leakage (referring to the battery cells returned by the customer after processing ); d. The customer did not spot welding as required (cells processed by the customer); e. Burrs; f. Micro-short circuit; g. The negative electrode produces dendrites.

  
  

• The reasons for over-thickness are as follows: 

  a. Weld leakage; b. Electrolyte decomposition; c. Undrying moisture; d. Poor sealing performance of cap; e. Shell wall too thick; f. Shell too thick; g. ; pole pieces not compacted; diaphragm too thick).

  
  

• Battery exploded 

  a. The sub-container is faulty (causing overcharge); b. The diaphragm closure effect is poor; c. Internal short circuit.

  
  

• Battery short circuita.Material dust; b. Broken when packing; c. Scraping (diaphragm paper is too small or not properly padded); d. Uneven winding; e. Not well wrapped; f. Diaphragm has holes; g. Burrs