Lithium ferrous phosphate and lithium ion batteries: comparison of voltage characteristics and safety

Lithium ferrous phosphate and lithium ion batteries are one of the most widely used battery types. In this paper, the voltage characteristics and safety comparison of these two batteries will be discussed in depth to help readers better understand their advantages and disadvantages.

Voltage characteristic

The typical voltage of lithium iron phosphate monomer is 3.2V, while the typical voltage of lithium ion battery is 3.7V V. ..

Security comparison

Lithium ferrous phosphate is stable in puncture experiment and will not catch fire or explode. Relatively speaking, lithium-ion batteries have potential safety hazards under similar conditions.

Overcharging safety

Lithium ferrous phosphate has excellent overcharge resistance, even if it is charged to 100%, it will not catch fire and explode. However, when the voltage of lithium-ion battery exceeds 4.35V, there is a risk of outgassing.

Overdischarge recovery

Lithium ferrous phosphate has the characteristics that it can still recover more than 80% capacity after short-term overdischarge to 0V; In contrast, lithium-ion batteries may be irreversibly damaged when overdischarged to 2.6V.

Brief introduction of battery materials

Lithium ferrous phosphate is used as the cathode material of lithium iron phosphate battery, and the cathode materials of lithium ion battery include lithium cobaltate, lithium manganate, lithium nickelate and ternary materials. Among them, lithium cobalt oxide is the most commonly used material at present.

Safety performance improvement

The P-O bond in LiFePO4 crystal is stable and difficult to decompose, and it will not cause the structure to collapse and heat or form strong oxidizing substances at high temperature or overcharge. Although combustion occurred under some extreme experimental conditions (such as acupuncture or short circuit), no explosion occurred. In the overcharge experiment, the safety of lithium cobaltate battery with liquid electrolyte has been greatly improved compared with the traditional lithium cobaltate battery, even if it is charged at a high voltage far exceeding its discharge voltage.