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Lithium iron phosphate battery refers to a lithium-ion battery that uses lithium iron phosphate as the positive electrode material. The positive electrode materials of lithium-ion batteries mainly include lithium cobalt oxide , lithium manganese oxide, lithium nickel oxide, ternary materials, lithium iron phosphate, etc. Among them, lithium cobalt oxide is the positive electrode material used by most lithium-ion batteries at present. From the principle of materials, lithium iron phosphate is also an embedding and de-embedding process, and this principle is exactly the same as that of lithium cobalt oxide and lithium manganese oxide.

Ternary lithium battery classification Ternary lithium batteries, that is, lithium batteries that use nickel cobalt manganese oxide ( NCM ) or nickel cobalt aluminum oxide (NCA) as the positive electrode material, have various classification methods according to different classification standards. 

  Introduction to Lithium-ion Batteries (LIB) Lithium-ion batteries are mainly composed of four parts: positive electrode materials, negative electrode materials, separators, and electrolytes . The positive electrode materials must participate in chemical reactions and also provide Li+ as a lithium ion source; the negative electrode materials are also an important component of the battery, generally carbon, lithium titanate, and silicon-based alloy materials; the main function of the separator is to prevent the positive and negative electrode materials from directly contacting each other and causing a short circuit, and it is generally a porous membrane material such as polyethylene or polypropylene; the role of the electrolyte is to provide a channel for the transmission of lithium ions and promote the reversible reaction of the electrode. It is mainly composed of electrolyte lithium salts, non-aqueous organic solvents, and necessary additives. Figure 1. Applications of lithium-io...

Lithium cobalt oxide is the first commercialized cathode material for lithium-ion batteries. Its theoretical gram capacity after complete delithiation is 274 mAh/g, its true density is as high as 5.1 g/cm  3  , and its actual compacted density can reach 4.2  g/cm  3.  It has an extremely high volume energy density (the advantage is prominent under high voltage) and is still the most widely used cathode material for consumer batteries.In fact, lithium cobalt oxide has three crystal structures, namely high-temperature phase HT-  LiCo  O  2  , low-temperature phase LT  - LiCo  O  2  , and rock salt phase LiCo  O  2.  Among them, the synthesis temperature of low-temperature phase lithium cobalt oxide is relatively low, and the crystal structure characteristics are between the layered structure and the spinel structure. The Li layer contains about 25% Co atoms, and the Co layer contains about 25% Li ato...

  3 2.What is the IEC standard cycle life test?   IEC stipulates that the standard cycle life test for NiMH batteries is:   After the battery is discharged at 0.2C to 1.0V/piece 01) Charge at 0.1C for 16 hours, then discharge at 0.2C for 2 hours and 30 minutes (one cycle)   02) Charge at 0.25C for 3 hours and 10 minutes, discharge at 0.25C for 2 hours and 20 minutes (2-48 cycles)   03) Charge at 0.25C for 3 hours and 10 minutes, discharge at 0.25C to 1.0V (49th cycle)   04) Charge at 0.1C for 16 hours, leave for 1 hour, and discharge at 0.2C to 1.0V (50th cycle). For NiMH batteries, repeat 1-4 for a total of 400 cycles, and the 0.2C discharge time should be greater than 3 hours; for NiCd batteries, repeat 1-4 for a total of 500 cycles, and the 0.2C discharge time should be greater than 3 hours.

  I. Some important concepts Lithium iron phosphate battery (LFP) and ternary lithium battery (NCM/NCA) are two mainstream lithium-ion battery technologies. The following are their main differences:

Lithium-ion battery overview Lithium-ion battery is a secondary battery. Its working principle is: during the charge and discharge process, lithium ions are in a state of movement from positive electrode → negative electrode → positive electrode. During the charge and discharge process, lithium ions are intercalated and deintercalated back and forth between the two electrodes. That is, during charging, lithium ions are deintercalated from the positive electrode and intercalated into the negative electrode through the electrolyte, and the negative electrode is in a lithium-rich state. The opposite is true during discharge. Lithium-ion batteries are complex systems consisting of positive electrode materials, negative electrode materials, electrolytes , separators, conductive agents, binders and packaging materials. Due to their high operating voltage, high specific energy density, long cycle life and wide operating temperature range, lithium-ion batteries have been widely used in new ene...

1. Electrolyte It is an important component of lithium batteries. It conducts lithium ions inside the battery and has an important impact on the performance and life of the battery. Lithium battery electrolyte is usually composed of organic solvents, electrolytes and additives.   Organic solvent is the main component of electrolyte, which is usually a flammable, explosive and toxic liquid, such as dimethyl carbonate (DMC), ethyl methyl carbonate (EMC), diethyl carbonate (DEC), etc.  These organic solvents can dissolve electrolytes to form ion conductors, and can also provide a certain electrochemical stability.   Electrolyte is an ion conductor in the electrolyte, which is usually a lithium salt,  such as LiPF6, LiBF4, LiClO4, etc. These lithium salts can dissociate into lithium ions and negative ions in the electrolyte, thereby realizing the conduction of lithium ions.   Additives are some chemical substances added to improve the performance of the electrolyt...

What is electrolyte? The main materials of lithium-ion batteries are: positive electrode, negative electrode, electrolyte, and separator  . As one of the four key materials of lithium-ion batteries, electrolyte is called the "blood" of lithium-ion batteries. From the working principle of lithium ions, lithium-ion batteries are secondary batteries (rechargeable batteries) that mainly rely on the movement of lithium ions between the positive and negative electrodes to work. During the charging and discharging process, Li+ is embedded and de-embedded between the two electrodes: when charging, Li+ is de-embedded from the positive electrode and embedded in the negative electrode through the electrolyte , and the negative electrode is in a lithium-rich state; the opposite is true during discharge.

  1. Composition of electrolyte The basic functions of electrolyte: It transfers lithium ions between the positive and negative electrodes, but insulates electrons to ensure that the battery can be charged and discharged smoothly. Ideal electrolyte requirements: 1) It is an excellent conductor for lithium ions and an insulator for electrons; 2) Except for the migration of lithium ions, no other side reactions occur on the electrode surface; 3) Do not react with other battery components; 4) Good chemical stability; safe and environmentally friendly;

  Lithium-ion battery:   A battery that uses materials that can undergo lithium ion embedding/de-embedding reactions as positive and negative active materials, and uses organic electrolytes or polymer electrolytes containing lithium salts. It is a secondary battery (i.e., a rechargeable battery) that mainly relies on the movement of lithium ions between the positive and negative electrodes to work.

This article introduces the role of lithium battery electrolyte in detail. The electrolyte not only plays a key role in conducting ions to complete the charging and discharging process in the battery, but also has important significance in maintaining the stable performance of the battery, preventing plate corrosion, dissipating heat, controlling temperature, improving energy and power density, providing high voltage and high specific energy, protecting battery safety, and adapting to wide temperature applications. By understanding the role of the electrolyte , it provides a reference for better design and optimization of lithium batteries and improving their performance and safety.

1. Why choose lithium battery? At present, most power batteries are still lithium batteries. Of course, sodium-ion batteries are gradually beginning to be mass-produced, but they are not the main players yet.

1. Classification of battery cells 1.1. Introduction to energy storage Nickel battery: Nickel-metal hydride battery is a good performance battery. The positive active material of nickel-metal hydride battery is Ni(OH)2 (called NiO electrode), the negative active material is metal hydride, also called hydrogen storage alloy (the electrode is called hydrogen storage electrode), and the electrolyte is 6mol/L potassium hydroxide solution. The advantages of nickel battery are: high energy density, fast charge and discharge speed, light weight, long life, no environmental pollution; the disadvantages are slight memory effect, more management problems, and easy formation of monomer battery separator melting.