How much do you know about the "lithium-ion battery" of new energy vehicles?
Why use lithium-ion batteries for electric vehicles? What are the advantages of lithium-ion batteries?
Advantages of lithium-ion batteries: no heavy metals, no heavy metals will pollute the soil; no memory effect can be charged and discharged at any time; high energy density is expected to reach 500wh/kg in 2020; long cycle life, cycle charge and discharge can reach more than 1000 times; The self-discharge rate is low, less than 2% per month; the energy conversion rate is as high as 96%. These advantages of lithium-ion batteries are the reason why lithium-ion batteries are in full swing in the field of electric vehicles.
Next, we understand the four critical raw materials of lithium-ion batteries: 1. Cathode material; 2. Anode material; 3. Electrolyte; 4. Separator. Among them, the cathode material is the carrier of lithium element (mainly lithium cobalt oxide, lithium manganate, lithium iron phosphate, ternary lithium, etc.); the anode material plays the role of storing and transferring lithium ions, and the primary material is graphite (silicon composite material It is the future development direction); electrolyte is the solvent for chemical reactions, mainly lithium salt and organic water; the function of the diaphragm is to isolate electrons, but it must also allow ions to pass through to prevent short circuits. The primary materials are polyethylene and polypropylene.
Ternary lithium currently mainly refers to ternary nickel-cobalt-manganese batteries. Nickel is the main electrochemically active element. Its content determines the cruising range of the vehicle to a certain extent; the content of cobalt determines the charging rate and cycle life; The content of elements determines the structural stability and thermal stability of the battery.