Are Lithium Iron Phosphate Batteries Safe?
The answer is safety. Lithium iron phosphate is currently the safest cathode material for lithium-ion batteries. It does not contain any heavy metal elements that are harmful to the human body. The oxygen in its olivine structure is difficult to precipitate, which improves the stability of the material. Next, we describe the safety of lithium iron phosphate batteries from three aspects: material/structural stability, production process, and charge-discharge characteristics.
- Materials of lithium iron phosphate battery
Lithium iron phosphate is the safest cathode material for lithium-ion batteries at present. It does not contain any heavy metal elements that are harmful to the human body. It is difficult to precipitate oxygen in its olivine structure, which improves the stability of the material.
- The production process of lithium iron phosphate battery
The production process of lithium iron phosphate battery is roughly the same as that of other lithium battery varieties. Its core processes are: batching, coating, rolling, filming, and winding.
In the batching process, the conductivity of lithium iron phosphate materials is relatively poor. Therefore, the particles are generally made smaller. The objective effect of this is that the internal arrangement is more uniform, which promotes the formation of a balanced voltage platform and can maintain the battery during operation. Status is stable.
- Charge and discharge characteristics of lithium iron phosphate battery
Charging and discharging are the two basic working states of C-rate lithium battery. When the lithium iron phosphate battery is charged and discharged, due to the weak oxidation ability of iron ions, it will not release oxygen, so it is naturally difficult to have a redox reaction with the electrolyte, which makes lithium iron phosphate The battery charging and discharging process is in a safe environment.
Not only that, it is difficult for lithium iron phosphate batteries to undergo severe redox reactions during high-rate discharge or even overcharge and discharge.
At the same time, after the lithium is deintercalated, the lattice change makes the final volume of the unit cell (the smallest constituent unit of the crystal) shrink, which just offsets the increased volume of the carbon anode during the reaction.
Therefore, the lithium iron phosphate battery can maintain the stability of the physical structure during charging and discharging, and eliminates the hidden danger of the battery bursting phenomenon caused by the increase in volume.
The safety of the battery is explained by taking a single cell as an example for the sake of convenience. When put into use, the lithium iron phosphate battery needs to provide the rated voltage and capacity suitable for electrical appliances.
At this time, it is necessary to carry out the lithium iron phosphate battery matching work, that is, the single lithium iron phosphate battery is equipped with a series/parallel/series-parallel method into a usable lithium battery pack. The most important thing for this matching work is that each Consistency of single cells.
Usually, it also has a balanced management system, which ensures the safety of the use of lithium batteries through the control of key parameters, which is a common feature of all kinds of lithium battery packs.