Benzo Battery News

Different types of batteries have different internal resistances. The same type of battery has different internal resistance due to the inconsistency of internal chemical characteristics. The internal resistance of the battery is very small, we generally use the unit of milliohm to mean it. Internal resistance is an important technical indicator to measure battery performance. Under normal circumstances, a battery with a small internal resistance has a strong high-current discharge capacity, and a battery with a large internal resistance has a weak discharge capacity. In terms of the schematic diagram of the discharge circuit, we can consider the battery and the internal resistance separately, and divide it into a power supply with no internal resistance at all and connect it with a small resistance in series. At this time, if the external load is light, then the voltage distributed to this small resistor is small. On the contrary, if the external load is very heavy, then the voltage distributed to this small resistor is relatively large, and part of the power will be consumed in this Internal resistance (may be converted into heating, or some complex reverse electrochemical reaction). The internal resistance of a rechargeable battery when it leaves the factory is relatively small, but after long-term use, due to the exhaustion of the battery’s internal electrolyte and the decrease in the activity of the internal chemical substances in the battery, this internal resistance will gradually increase until the internal resistance is large enough. The power inside the battery cannot be released normally, and the battery is dead at this time. The vast majority of aging batteries are useless due to excessive internal resistance and have to be scrapped. Therefore, we should pay more attention to the discharged capacity of the battery rather than the charged capacity.

At present, major lithium battery manufacturers have designed various types of lithium battery protection chips for different types of lithium-ion battery overcharge, overdischarge, and overcurrent protection requirements to ensure battery safety performance and avoid deterioration of battery characteristics. Most of these lithium battery protection chips are suitable for lithium-ion batteries with 1-4 cells in series, and very few new products, such as Texas Instruments' BQ77PL900 chip, are suitable for lithium-ion batteries with 5-10 cells in series, and their protection functions Perfect and widely used in many lithium battery protection circuits. However, for many serial numbers, such as battery packs with more than 10 strings of lithium batteries in series or the number of protection chips are different from the actual number of lithium battery packs in series, if the current integrated circuit chips on the market are used to make the protection circuit, there will be no The disadvantage of not being flexible enough to achieve protection or use.

Low-temperature lithium-ion batteries are classified according to their discharge performance: energy storage low-temperature lithium-ion batteries, rate-type low-temperature lithium-ion batteries.

Lithium-ion batteries often have certain failure phenomena during use or storage, including capacity decay, internal resistance increase, rate performance reduction, gas production, liquid leakage, short circuit, deformation, thermal runaway, lithium evolution, etc., which seriously reduce lithium ion The performance, reliability and safety of the battery. These failure phenomena are caused by the interaction of a series of complex chemical and physical mechanisms inside the battery.

Lithium-ion battery has a high energy density, its capacity is 1.5 to 2 times that of a nickel-hydrogen battery of the same weight, and it has a very low self-discharge rate. In addition, lithium-ion batteries have almost no "memory effect" and do not contain toxic substances. These advantages of lithium-ion batteries make it widely used in the field of new energy vehicles.

Lithium-ion batteries and lead-acid batteries are currently the two most widely used batteries. So what is the difference between these two batteries and which one is better? The following will focus on the difference between lithium-ion batteries and lead-acid batteries.

For lithium batteries, our focus is often on capacity and energy density. These data can usually directly reflect the length of the battery's cruising range. But what we should note is that most lithium batteries are the products of electrochemistry. Since they are related to chemistry, their performance has a great relationship with temperature.

Ternary lithium ion battery refers to a lithium ion battery that uses three transition metal oxides of nickel, cobalt, and manganese as the positive electrode material. Because it combines the advantages of lithium cobalt oxide, lithium nickel oxide and lithium manganate, it has excellent performance for any of the above single-component cathode materials.

The 18650 type lithium battery is a more commonly used lithium battery in electronic products, and is often used as a cell in the battery pack of a notebook computer. When we use it, we find that sometimes the 18650 lithium battery cannot be charged. Let's analyze the reason below.

The lithium battery protection circuit board is mainly composed of protection IC (overvoltage protection) and MOS tube (overcurrent protection), and is a device used to protect the safety of lithium battery cells. Lithium batteries are widely used by people for their large discharge current, low internal resistance, long life, and no memory effect. Lithium-ion batteries are strictly prohibited from overcharging, overdischarging, and short-circuiting during use, otherwise it will cause the battery to catch fire and explode. Therefore, when using rechargeable lithium batteries, there will be a protective circuit board to protect the safety of the batteries.