Many people who buy new energy vehicles will be confused about the battery type. The difference between ternary lithium and lithium iron phosphate batteries mainly lies in the cathode material. Among them, the cathode material of ternary lithium battery is "nickel salt, cobalt salt, manganese salt/lithium aluminate", while the cathode material of lithium iron phosphate battery uses "phosphate of lithium iron”. In addition, electrolytes and negative electrode materials use lithium hexafluorophosphate and graphite.
To decide which is better, a ternary lithium battery or a lithium iron phosphate battery, you need to determine the advantages and disadvantages between the two. But in general, if the local climate is relatively cold, it is better to choose ternary lithium batteries. If it's not so cold, comme in Guangdong, it is better to choose lithium iron phosphate batteries.
Why specifically, we need to clearly understand the pros and cons between the two. Let's look at lithium iron phosphate batteries first:
Advantages
1. It does not contain precious metal elements such as cobalt, and the raw materials are easy to obtain and the cost is low;
2. The battery has resistance to high temperature, thermal runaway. the temperature can reach about 800 degrees and has good safety performance;
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3. The battery cycle life can reach more than 3500 times, and some can even reach 5000 times, which has a long service life. lifespan;
4. The working voltage of the battery is 3.2-3.4V, which can meet the basic requirements of vehicle batteries;
5. It's always 80% ofstored energy and recycling value is high.
Disadvantages
1. Poor performance at low temperatures At around minus 20 degrees, the battery will decompose to about 55%;
2, the energy density is low. Every time it reaches 150wh/kg, the volume/weight of the battery will be larger.
3. The battery has a long life, but the battery has a short life, usually about 500 times
4. ;
5, The performance of the battery process is unstable and the consistency is poor.
Ternary lithium battery
Advantages
1. The battery output voltage reaches 3.7V, which is large energy, higher specific power;
2. Good high rate charging performance and fast charging speed
3. Good low temperature performance, battery heating performance is still good;at minus 20 degrees Reaching more than 70%;
4. The energy density is high, up to more than 200 Wh per kilogram, and the battery size and weight will be smaller.
5. High discharge voltage and good output power.
Disadvantages
1. Low lifespan, basically about 2500 times
2 Not resistant to high temperatures, thermal runaway; temperature At about 200 degrees, the safety performance is poor;
3. The battery contains precious metals such as cobalt and the material cost is high
4. is high.
Lithium-ion batteries are harmful to the human body.
The most harmful thing is the electrolyte solution. The electrolyte is a volatile organic liquid and is obviously corrosive. Long-term inhalation of volatile gases can cause damage to the respiratory tract. Cause respiratory illness.
Lithium-i batteriesthey emit certain radiation because they contain cadmium, which can cause osteoporosis.
The work environment can contain many harmful elements. Some mercury elements are relatively common, and there are other lead elements. Causes heavy metal-related illnesses.
Like all chemical batteries, lithium-ion batteries are made up of three parts: a positive electrode, a negative electrode and an electrolyte. The electrode materials are all lithium ions which can be intercalated (inserted)/deintercalated (deintercalated).
Lithium-ion battery electrolyte solution
Solute: Lithium salts are often used, such as lithium perchlorate (LiClO4), lithium hexafluorophosphate (LiPF6) and lithium tetrafluoroborate (LiBF4). Solvent: Since the operating voltage of the battery is much higher than the decomposition voltage of water, the batteriesLithium ion batteries often use organic solvents, such as ether, ethylene carbonate, propylene carbonate, diethyl carbonate, etc.
Organic solvents often destroy the structure of graphite during charging, causing it to delaminate and form a solid electrolytic interphase (SEI) on its surface, leading to passivation of the electrodes. Organic solvents also pose safety concerns such as flammability and explosiveness.
The positive electrode materials of lithium batteries include lithium cobalt oxide LiCoO2, ternary material Ni+Mn+Co, lithium manganate LiMn2O4 as well as a conductive agent and an adhesive, which are coated on an aluminum foil to form a positive electrode, and the negative electrode is layered with graphite plus a conductive agent and an adhesive are coated on the copper foil base tape. So far, graphit particlesThe most advanced negative electrode layers have adopted nanocarbon.
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