What are the classifications of lithium batteries? Detailed explanation of the mainstream technology of power lithium batteries -Lithium - Ion Battery Equipment
Power lithium batteries for new energy vehicles can be divided into secondary batteries (including lead-acid batteries, nickel-cadmium batteries, nickel-metal hydride batteries, and lithium-ion batteries) and fuel power batteries.
We will refine it, starting from the classification of lithium-ion batteries, and analyze the mainstream technical routes of power lithium batteries currently on the market.
working principle
First of all, correct a concept. Lithium-ion batteries are usually divided into two categories according to the materials used in the positive and negative electrodes:
Lithium metal batteries are batteries that use manganese dioxide as the positive electrode material and metallic lithium or its alloy metal as the negative electrode material; lithium ion batteries use lithium alloy metal oxide as the positive electrode material and graphite as the negative electrode material.(Lithium - Ion Battery Equipment)
Lithium metal batteries are not stable enough and cannot be recharged, so they are not secondary batteries. Regarding new energy vehicles, the lithium-ion battery we usually refer to refers to the lithium-ion battery.
Lithium-ion batteries are mainly composed of four parts: positive electrode (lithium-containing compound), negative electrode (carbon material), electrolyte, and separator:
When the battery is charging, lithium atoms on the positive electrode are ionized into lithium ions and electrons (deintercalation). The lithium ions move to the negative electrode through the electrolyte, obtain electrons, and are reduced to lithium atoms and embedded in the micropores of the carbon layer (insertion);
When the battery is discharged, the lithium atoms embedded in the carbon layer of the negative electrode lose electrons (deintercalation) and become lithium ions, which pass through the electrolyte and move back to the positive electrode (intercalation);
The charging and discharging process of lithium-ion batteries is the process of continuous embedding and deintercalation of lithium ions between the positive and negative electrodes, accompanied by the embedding and deintercalation of equivalent amounts of electrons. The greater the number of lithium ions, the higher the charge and discharge capacity.
Classification
Due to different cathode materials, lithium-ion batteries are mainly divided into: lithium iron phosphate (LFP), lithium nickel oxide (LNO), lithium manganate (LMO), lithium cobalt oxide (LCO), and lithium nickel cobalt manganate (NCM). ), ternary lithium nickel cobalt aluminate (NCA), and the negative electrode material mainly uses graphite carbon material.
The chemical composition, structure and important properties of each type are compared as follows:
Technical route
Based on the above table, let’s take a look at the application of different types of lithium-ion batteries in the market.
Let’s talk about lithium cobalt oxide first. As the originator of lithium-ion batteries, of course, it may also be used as a power lithium battery to try the water first. It was first used in Tesla Roadster. However, due to its low cycle life and safety, the fact It proves that it is not suitable as a power lithium battery. In order to make up for this shortcoming, Tesla uses what is known as the world's best battery management system to ensure battery stability. Lithium cobalt oxide currently has a large market share in the 3C field.
The second is lithium manganate batteries, which were first proposed by the battery company AESC. This AESC has a big background and is a joint venture between Nissan and Nippon Electric Co., Ltd. (NEC). The representative model of lithium manganate is the Nissan Leaf. Due to its low price, medium energy density, average safety, and so-called good overall performance. The so-called success or failure is also a failure. It is precisely because of this tepid characteristic that it is gradually replaced by new technologies.
Next is lithium iron phosphate. As BYD's flagship product, it has good stability, long life, and cost advantages. It is especially suitable for plug-in hybrid vehicles that require frequent charging and discharging. However, its disadvantage is that the energy density is average.
Finally, there is the ternary lithium-ion battery. As a rising star, it has the highest energy density, but its safety is relatively poor. Regarding pure electric vehicles with required cruising range, they have broader prospects and are the current mainstream direction of power lithium batteries.
We will refine it, starting from the classification of lithium-ion batteries, and analyze the mainstream technical routes of power lithium batteries currently on the market.
working principle
First of all, correct a concept. Lithium-ion batteries are usually divided into two categories according to the materials used in the positive and negative electrodes:
Lithium metal batteries are batteries that use manganese dioxide as the positive electrode material and metallic lithium or its alloy metal as the negative electrode material; lithium ion batteries use lithium alloy metal oxide as the positive electrode material and graphite as the negative electrode material.(Lithium - Ion Battery Equipment)
Lithium metal batteries are not stable enough and cannot be recharged, so they are not secondary batteries. Regarding new energy vehicles, the lithium-ion battery we usually refer to refers to the lithium-ion battery.
Lithium-ion batteries are mainly composed of four parts: positive electrode (lithium-containing compound), negative electrode (carbon material), electrolyte, and separator:
When the battery is charging, lithium atoms on the positive electrode are ionized into lithium ions and electrons (deintercalation). The lithium ions move to the negative electrode through the electrolyte, obtain electrons, and are reduced to lithium atoms and embedded in the micropores of the carbon layer (insertion);
When the battery is discharged, the lithium atoms embedded in the carbon layer of the negative electrode lose electrons (deintercalation) and become lithium ions, which pass through the electrolyte and move back to the positive electrode (intercalation);
The charging and discharging process of lithium-ion batteries is the process of continuous embedding and deintercalation of lithium ions between the positive and negative electrodes, accompanied by the embedding and deintercalation of equivalent amounts of electrons. The greater the number of lithium ions, the higher the charge and discharge capacity.
Classification
Due to different cathode materials, lithium-ion batteries are mainly divided into: lithium iron phosphate (LFP), lithium nickel oxide (LNO), lithium manganate (LMO), lithium cobalt oxide (LCO), and lithium nickel cobalt manganate (NCM). ), ternary lithium nickel cobalt aluminate (NCA), and the negative electrode material mainly uses graphite carbon material.
The chemical composition, structure and important properties of each type are compared as follows:
Technical route
Based on the above table, let’s take a look at the application of different types of lithium-ion batteries in the market.
Let’s talk about lithium cobalt oxide first. As the originator of lithium-ion batteries, of course, it may also be used as a power lithium battery to try the water first. It was first used in Tesla Roadster. However, due to its low cycle life and safety, the fact It proves that it is not suitable as a power lithium battery. In order to make up for this shortcoming, Tesla uses what is known as the world's best battery management system to ensure battery stability. Lithium cobalt oxide currently has a large market share in the 3C field.
The second is lithium manganate batteries, which were first proposed by the battery company AESC. This AESC has a big background and is a joint venture between Nissan and Nippon Electric Co., Ltd. (NEC). The representative model of lithium manganate is the Nissan Leaf. Due to its low price, medium energy density, average safety, and so-called good overall performance. The so-called success or failure is also a failure. It is precisely because of this tepid characteristic that it is gradually replaced by new technologies.
Next is lithium iron phosphate. As BYD's flagship product, it has good stability, long life, and cost advantages. It is especially suitable for plug-in hybrid vehicles that require frequent charging and discharging. However, its disadvantage is that the energy density is average.
Finally, there is the ternary lithium-ion battery. As a rising star, it has the highest energy density, but its safety is relatively poor. Regarding pure electric vehicles with required cruising range, they have broader prospects and are the current mainstream direction of power lithium batteries.
