Basics of Lithium Battery


(1) The classification of lithium-ion battery
Steel Shell Lithium Ion battery
Early-stage lithium-ion batteries are mostly steel shells, more for mobile phone batteries, after the steel shell weight than energy, and security is poor, gradually replaced by aluminum shell and soft packaging lithium-ion battery. There are still some small factories using steel shells to make B-products cell phone batteries and some low value-added MP3, MP4 batteries.
But in the cylindrical lithium battery, there is another scene, the vast majority of manufacturers are steel as the battery shell material, because the physical stability of steel materials, the resistance is much higher than the aluminum shell material, after the design structure of each factory is optimized, the safety device has been placed inside the battery core, the safety of the Steel Shell column battery has reached a new height, and you can’t see the most of the laptop batteries in the notebook are the steel shells as the carrier.

Aluminum Shell Lithium Ion battery
Aluminum shell Lithium-ion battery because of the lighter quality and safer than the steel shell lithium-ion battery, has become the main force of mobile phone batteries. Due to the high cost of aluminum shell open mold, so the model is relatively small, and order quantity requirements are higher, the main models focus on some common cell phone battery models.
 applications of lithium battery
Lithium Ion polymer battery
Soft packaging Lithium-ion battery because of its light weight, low cost of open mold, high security advantages, gradually expanding its market share. Mainly used in digital products, is also gradually to mobile phones, notebook computers, electric tools and other market development. Can be foreseen in the next few years soft packaging lithium-ion battery market share will continue to expand steadily, the scope of application is more extensive, because the outsourcing of aluminum plastic film, resistance is weak, limited to the current domestic packaging plant technology and environmental restrictions, the proportion of the bulge is still relatively high.
(2) Classification of cathode materials for lithium ion batteries
Lithium Cobalt acid cathode material
At present, the largest and most common cathode material of lithium ion battery, its structure is stable, the ratio is high, the comprehensive performance is outstanding, but its security is poor, the cost is very high, mainly uses in medium and small size electric core, nominal voltage 3.7V.

Lithium Manganese oxide cathode material
A low cost, safe and good cathode material, but the material itself is not very stable, it is easy to decompose and produce gas, so it is used to mix with other materials to reduce the cost of the core, but its cycle life attenuation is faster, prone to bulging, life is relatively short, mainly used for large and medium-sized electric core, power battery, its nominal voltage of 3.8V.

Lithium nickel cobalt manganese ternary cathode material

A more balanced material in terms of capacity and safety, with better cycling performance than normal lithium cobalt acid, Due to technical reasons, the nominal voltage is only 3.5-3.6V, Limited in terms of use, but at present, with the formulation of continuous improvement and structural improvement, the battery nominal voltage has reached 3.7V, has reached or exceeded the level of lithium cobalt, global 5 big electric Core brand Sanyo, Panasonic, Sony, LG, Samsung has launched ternary materials of the electric core, a considerable part of the note-type battery line are used ternary materials replacement of the former cobalt acid lithium batteries, Sanyo, Samsung Column Battery is the overall shutdown of the cobalt-acid lithium-ion core steering ternary core system , most of the small high rate power batteries at home and abroad use ternary cathode materials.

Lithium iron phosphate cathode material
At present, a new type of lithium-ion battery material is widely concerned, its prominent feature is the safety is very good, will not explode, the cycle performance is very good to reach 2000 weeks, these characteristics make it very suitable for electric vehicles, electric tools and other fields. Its nominal voltage is only 3. $number. 3V, so the protection line part is also different from the commonly used lithium-ion batteries, but his shortcomings are also more obvious, energy density is far lower than lithium cobalt and ternary materials.

(3) Main structural components of lithium ion batteries
Cathode materials (lithium cobalt, lithium manganese oxide, lithium iron phosphate, nickel cobalt manganese oxide lithium, lithium nickel cobalt acid, etc.)
Anode materials (artificial graphite, modified natural graphite, etc.)
Diaphragm material (polyethylene film, polypropylene film or composite film of both)
Electrolyte (EC, PC, Dec, DMC, EMC and other solvents and six lithium fluoride phosphate solution)
Positive and negative extreme (positive or negative)
Housing (steel shell, aluminum shell, aluminum plastic film)

(4) The working principle of lithium ion battery

Principle of lithium battery

(5) Application of lithium ion battery
Consumer Electronics: Notebook computer batteries, cell phone batteries, digital camera batteries, electric bicycle batteries.
Industrial instruments: Electric tools battery, pos battery, electric cleaner battery, light curing machine battery and so on.