Why Do Electric Cars Use Lithium-Ion Batteries? Because 'Lithium' Carries Cargo

At present, most pure electric vehicle batteries for passenger vehicles have given up lithium iron phosphate as the positive electrode material and switched to ternary lithium materials nmp. The main reason is that the requirements for battery performance are higher, that is, the requirements for cruising range are higher.

Why is the active ingredient of the battery "lithium"? What is the purpose and significance of the positive electrode material in different product formulations?

The development of chemical batteries has a history of more than 200 years 1 methyl 2 pyrrolidone. Lithium-ion batteries have become mainstream. You may wonder, there are more than 100 elements on the periodic table, why must it be lithium?

How Lithium-Ion Batteries Work

The new energy vehicle lithium-ion battery is a rechargeable battery that mainly relies on lithium ions to move between the positive and negative electrodes to generate current. There are many cathode materials for lithium-ion batteries, all of which exist in the form of embedded lithium compounds nmp solvent. At present, the cathode materials for automotive power batteries include lithium iron phosphate, ternary lithium (divided into nickel-cobalt-manganese system and nickel-cobalt-aluminum system), etc. The current mainstream of negative electrode material is graphite.

During the discharge process of Li-ion batteries, lithium ions are intercalated into the cathode, while during the charging process, lithium ions are deintercalated into the cathode. During charge and discharge, lithium ions move from cathode to cathode through the electrolyte and separator.

This is like a logistics vehicle driving at point A and point B in a city. The non-stop shuttle between them brings "current" to the city of this country, and one of the lithium elements is through which work efficiency Reach the highest level, the logistics vehicle with the strongest carrying capacity.

Why can lithium element be a material for rechargeable batteries?

Before the application of lithium, people have been looking for suitable battery materials as a device for storing electrical energy. People have tried a variety of battery materials, such as copper, iron, zinc, lead, mercury, magnesium, etc. The main improvement direction of the battery is to improve the capacity and discharge performance, and finally choose lithium as the latest generation of battery material.

Why is the active ingredient of the battery "lithium" instead of gold, silver, copper, iron and tin?

It is clear from the periodic table that lithium is the third and highest metal.

Lithium itself is six atomic mass units, each carrying a charge;

Compared with zinc, which was widely used in early battery technology, its atomic service quality is 66, and each zinc carries 2 charges. Obviously, using lithium as a battery research material can bring more obvious and higher energy density . That is to say, lithium, as a main battery material, has a higher specific capacity requirement.

In addition, the lithium-ion battery has the advantages of no memory effect, high charge-discharge rate, low self-discharge rate, and high energy conversion rate.

To transport materials from the earth to the space station, although the light rocket has less load, it needs to be launched several times, and the cost is lower than that of the heavy rocket. Lithium is like this light rocket, much more efficient.

Why are ternary lithium batteries replacing lithium iron phosphate and becoming the mainstream?

At present, most pure electric vehicle batteries for passenger vehicles have given up lithium iron phosphate as the positive electrode material and switched to ternary lithium materials. The main reason is that the requirements for battery performance are higher, that is, the requirements for cruising range are higher.

For example, for a company, the same cost and motorcycle technology can run much faster than a car, but the safety of our two wheels of meat-clad iron will be worse, which is very similar to lithium iron phosphate and ternary lithium batteries Develop comparative differences between characters.

The advantages and disadvantages of lithium iron phosphate and lithium ternary alloys are obvious. The disadvantage of lithium iron phosphate is low capacity density, but better security. The energy density of lithium ternary batteries is obviously higher, but the safety is relatively common. In order to pursue higher durability, lithium ternary batteries have become the mainstream.

It is precisely because of the energy density that lithium iron phosphate is gradually replaced by "ternary lithium battery" for the following reasons:

The energy density of the ternary lithium battery is significantly higher, and the most direct benefit is to expand the range;

Subsidy policies in and before 2018 directly encouraged high energy density batteries;

The new positive electrode structure material of ternary lithium battery has a greater potential to provide energy distribution density, such as NCM811 (the ratio of nickel, cobalt and manganese is 8:1:1).

Why is it called a triple lithium battery? What is the purpose of the different formulations of cathode materials?

The social title of "ternary lithium battery" is actually very simple.

This lithium-ion battery uses an intercalated lithium compound as the cathode material. In order to improve battery performance, people try to use different material combinations to improve battery performance. It has been found that the positive electrode materials of "NCM" and "NCA" systems have better performance, because these two positive electrode materials have three active components, so they are called "Ternary Lithium" battery.