Lithium Battery Knowledge

Ternary lithium-ion batteries refer to lithium-ion batteries that use three transition metal oxides of nickel, cobalt, and manganese as cathode materials. Compared with lithium iron phosphate batteries, ternary lithium-ion batteries have more average overall performance and higher energy density. high, the volume specific energy is also higher. Because it combines the advantages of lithium cobaltate, lithium nickelate and lithium manganate, its performance is better than any of the above single-component cathode materials.

Lithium manganese iron phosphate (LiMnxFe1-xPO4) is a new type of phosphate lithium-ion battery cathode material formed by doping a certain proportion of manganese (Mn) on the basis of lithium iron phosphate (LiFePO4). Through the doping of manganese element, on the one hand, the advantageous characteristics of iron and manganese can be effectively combined, and on the other hand, manganese and iron are both located in the fourth periodic subgroup and adjacent to the periodic table, and have similar ions Radius and some chemical properties, so doping will not significantly affect the original structure.

LiFePO4 battery is one of the Lithium battery, Because the cathode materials of LiFePO4 batteries are mainly compounds of phosphorus, acid, iron and lithium. Generally speaking, the voltage range of LiFePO4 battery is basically between 3.2V-3.6V. Among them, the nominal voltage is 3.2V, and the high-level termination charging voltage is 3.6V. However, the positive and negative materials, electrolytes, and production processes used by various manufacturers are different, so there will be differences in performance.

Many people will be entangled in the type of battery when purchasing new energy vehicles. In fact, the difference between ternary lithium battery and lithium iron phosphate battery mainly lies in the positive electrode material. Among them, the positive electrode material of ternary lithium battery is nickel salt, cobalt salt, manganese salt, and the positive electrode material of lithium iron phosphate battery is lithium iron phosphate. In addition, the electrolyte and anode materials of both use lithium hexafluorophosphate and graphite.

Lithium manganate battery refers to a battery whose positive electrode uses lithium manganate material. The nominal voltage of lithium manganate battery is 2.5~4.2v. Lithium manganate battery is widely used because of its low cost and good safety. Lithium manganate battery is a cathode material with low cost, good safety and low temperature performance, but the material itself is not very stable, and it is easy to decompose to generate gas, so it is mostly used in combination with other materials to reduce the cost of the cell, but its cycle The lifespan decays rapidly, bulging easily occurs, the high temperature performance is poor, and the lifespan is relatively short. It is mainly used for large and medium-sized batteries. In terms of power batteries, its nominal voltage is 3.7V.

With the development of lithium battery technology, there are more and more types of cylindrical lithium batteries. Cylindrical lithium ion batteries are divided into lithium cobalt oxide, lithium manganate, and ternary materials. The three material system batteries have different advantages. Let's take a look at the models and specifications of cylindrical lithium batteries.

A slight swelling of the polymer lithium battery will affect the use, reduce the battery performance, and in severe cases will burst the packaging aluminum foil, causing leakage and corrosion. Next, let's analyze the reasons for the inflation of polymer lithium batteries.

Lithium-ion batteries are widely used because of their light weight, large capacity, and no memory effect—many digital devices today use lithium-ion batteries as power sources, although they are relatively expensive. Lithium-ion batteries have high energy density, their capacity is 1.5 to 2 times that of nickel-metal hydride batteries of the same weight, and they have a very low self-discharge rate. In addition, lithium-ion batteries have almost no "memory effect" and the advantages of no toxic substances are also important reasons for their widespread use.

Commonly used conductive agents for lithium-ion batteries can be divided into traditional conductive agents (such as carbon black, conductive graphite, carbon fiber, etc.) and new conductive agents (such as carbon nanotubes, graphene and their mixed conductive pastes, etc.). The types of conductive agents on the market are SPUERLi, S-O, KS-6, KS-15, SFG-6, SFG-15, 350G, acetylene black (AB), Ketjen black (KB), vapor grown carbon fiber (VGCF) , carbon nanotubes (CNTs), etc.

In the structure of lithium batteries, the separator is one of the key inner layer components. The performance of the lithium-ion battery separator determines the interface structure and internal resistance of the battery, which directly affects the capacity, cycle and safety performance of the battery. The separator with excellent performance plays an important role in improving the overall performance of the battery.