Is LiFePO4 Battery Really Safe?
Nowadays, people who buy power station objectively have to choose between LiFePO4 battery and lithium battery. Insiders tell us: now power station pays more attention to safety, and it is best to choose to work at high temperatures. And LiFePO4 power station with overcharge protection. In this regard, consumers eagerly hope that industry insiders can give practical answers from a technical point of view: Are lithium iron phosphate batteries safe? This question should be answered from three aspects: material/structure stability, production process, and charge and discharge characteristics.
1. LiFePO4 is currently the safest cathode material for lithium-ion batteries. It does not contain any heavy metal elements harmful to the human body. Oxygen is difficult to precipitate in its olivine structure, which improves the stability of the material.
2. The production process of LiFePO4 battery is roughly the same as that of other lithium battery types. Its core processes are: batching, coating, rolling, sheeting, and winding. In the batching process, the conductivity of LiFePO4 material is relatively poor. Therefore, the particles are generally made smaller. The objective effect of this is: the internal arrangement is more uniform, which promotes the formation of a balanced voltage platform, which can maintain the battery during work. The state is stable.
3. Charging and discharging are the two basic working states of LiFePO4 battery. When the LiFePO4 battery is charged and discharged, the iron ion has a weak oxidation ability and will not release oxygen. Naturally, it is difficult to undergo a redox reaction with the electrolyte. This makes the LiFePO4 battery charging and discharging process in a safe environment. Not only that, it is difficult for LiFePO4 batteries to undergo violent oxidation-reduction reactions during high-rate discharge, even during overcharge and discharge. At the same time, after lithium is deintercalated, the crystal lattice changes to reduce the final volume of the unit cell (the smallest constituent unit of the crystal), which just offsets the increase in the volume of the carbon anode during the reaction. Therefore, the LiFePO4 battery can be maintained during charging and discharging. The stability of the physical structure eliminates the hidden danger of battery explosion caused by the increase in volume.
The battery safety mentioned above is explained by using a single unit as an example for convenience. When putting into use, LiFePO4 battery needs to provide rated voltage and capacity suitable for electrical appliances. At this time, LiFePO4 battery matching work is required. That is, the single LiFePO4 battery is equipped into a practical LiFePO4 battery pack through series/parallel/series-parallel methods. The most important thing to pay attention to in this kind of grouping work is the consistency of the individual cells. Usually, it also comes with a balance management system to ensure the safety of the LiFePO4 battery pack through the control of key parameters, which is a common feature of all types of battery packs.