How lithium ion batteries work
The definition of the lithium-ion battery: carbon as the negative electrode and lithium-containing compounds as the positive electrode; in the process of charge and discharge, there is no metal lithium, only lithium-ion, which is the origin of the name of lithium-ion battery.
development history
Lithium-ion battery-how it works
In the process of charge and discharge of the lithium ion battery, lithium ion is in the state of movement from the positive pole “negative pole” to the positive pole. It’s like a rocking chair. The two ends of the rocking chair are the poles of the battery, and the lithium ions move back and forth at both ends of the rocking chair. This kind of electrochemical energy storage system is vividly called “rocking chair battery”.
Lithium ion battery-battery structure
Lithium-ion batteries-classified by shell structure
Classified by shell material
Classified by cell structure
Classification by cathode material
| Cathode material | Lithium titanate | NCM | Lithium cobalt | LiMn2O4 | Lithium iron phosphate |
| Nominal voltage | 1.5V | 3.6V | 3.7V | 3.8V | 3.2V |
| Energy ratio | 45-55wh/kg | 170wh/kg | 150-160wh/kg | 100wh/kg | 100-140wh/kg |
| Cycle life / time | ＞9000 | >1000 | >300 | >500 | >2000 |
| Security | Excellent | Better | Poor | Good | Excellent |
| Operating temperature range | -30-60℃ | -20-55℃ | -20-55℃ | -20-55℃ | -20-70℃ |
| Rate discharge performance | ≤10C | ≤5C | ≤100C | ≤10C | ≤10C |
| Possibility of material price reduction | There is a certain amount of space. | There is a certain amount of space. | Small/limited | Small/limited | The price can be reduced a lot. |
| Energy application ratio | 90-95% | 60-70% | 95-98%(applied to 3C products) | 90-95% | 90-95% |
| Advantages | Good cycle performance, high stability, fast charging | Good stability at high temperature and good resistance to dielectric corrosion | Good comprehensive electrical performance and high gram capacity | Manganese is rich in resources, easy to prepare, and safe. | High stability, safety, and reliability, good cycle performance, excellent high-temperature performance, low temperature-20 ℃ can work normally. |
| Shortcoming | The discharge voltage platform is low, the energy density is low, and the price is expensive. | The lattice of the material has been distorted during charge and discharge, and the cycle performance is poor. | Poor security and high cost | The solubility of the material is low, and lattice distortion has occurred in deep charge and discharge, resulting in rapid depletion of battery capacity. | The electrical conductivity is general and the vibrating density is low. |
| Comprehensive price ratio | Low | General | General | Low | High |
Production technology of lithium battery
