Lithium Battery Knowledge

Overcharge refers to the behavior of continuing to charge the battery after it has been fully charged in a certain charging process. Over-discharge means that the battery has discharged the internally stored power, after the voltage reaches a certain value, continuing to discharge will cause over-discharge.

Can lithium battery packs do not need a protection circuit board? Is it necessary for protection circuit board of a lithium iron phosphate battery pack to be useful? What happens if the lithium battery does not have a protection circuit board? Generally, batteries have a protection circuit board, and the use of the protection circuit board is also for battery safety. But different types of battery protection circuit boards have different functions. I heard that lithium iron phosphate battery packs are not afraid of overcharging or over-discharging, so some people think that lithium batteries do not need a protective circuit board. Today we will answer these questions for you.

The consistency of lithium-ion battery packs should be judged by using special tools to measure capacity, internal resistance, and charge and discharge curves.

If the remaining capacity/initial capacity=80% is used as the end point of the test, the current 1C cycle life of the lithium iron phosphate battery laboratory is more than 3500 times, and some reach 5000 times, while the 1C cycle life of the ternary lithium ion battery laboratory is 2500 times about. In terms of the true cycle life, the lithium iron phosphate battery pack has a much longer true cycle life than the ternary lithium ion battery. Under the same number of cycles, the remaining capacity of the lithium iron phosphate battery is much more than that of the ternary lithium ion battery.

Lithium-ion polymer batteries are widely used due to their long life and high capacity. However, there are some issues that can arise, such as swelling, unsatisfactory safety performance, and accelerated cycle life attenuation.

Lithium polymer battery ( Li-polymer battery ), is a chemical battery. Compared with the previous battery, it has the characteristics of high energy, miniaturization and light weight. Lithium polymer batteries have ultra-thin features, and can be made into batteries of different shapes and capacities to meet the needs of some products. The theoretical minimum thickness can reach 0.5mm.

What's UL1642 certification? What's UL1642 standard for polymer lithium-ion battery? What's the test items of UL1642 certification?

Since the lithium-ion battery entered the market, it has been widely used due to its advantages such as long life, large specific capacity and no memory effect. Low-temperature use of lithium-ion batteries has problems such as low capacity, severe attenuation, poor cycle rate performance, obvious lithium evolution, and unbalanced lithium extraction. However, with the continuous expansion of application areas, the restrictions brought by the low-temperature performance of lithium-ion batteries have become more and more obvious.

Safety comparison of lithium cobaltate, lithium iron phosphate and polymer lithium batteries. Many customers have a lot of disputes about the safety performance of lithium batteries. Compared with lithium cobalt oxide batteries and polymer lithium batteries, the most obvious advantage of lithium iron phosphate batteries is the extremely high safety factor and support for fast charging (high current charging). And a wider operating temperature range.

The use of lithium batteries is restricted in low temperature environments. Except for the severe deterioration of discharge capacity, lithium batteries cannot be charged at low temperatures. During low-temperature charging, the intercalation of lithium ions on the graphite electrode of the battery and the lithium plating reaction coexist and compete with each other. Under low temperature conditions, the diffusion of lithium ions in graphite is inhibited, and the conductivity of the electrolyte decreases, resulting in a decrease in the intercalation rate and the lithium plating reaction on the graphite surface is more likely to occur. The main reasons for the decrease in the life of lithium-ion batteries when used at low temperatures are the increase in internal impedance and the degradation of the capacity due to the precipitation of lithium ions.