The power battery is called the heart of an electric vehicle; the brand, material, capacity, safety performance, etc. of an electric vehicle's battery have become important "dimensions" and "parameters" for measuring an electric vehicle. Currently, the battery cost of an electric vehicle is generally 30%-40% of the entire vehicle, which can be said to be a core accessory!
Currently, the mainstream power batteries used in electric vehicles on the market are generally divided into two types: ternary lithium batteries and lithium iron phosphate batteries. Next, let me briefly analyze the differences and advantages and disadvantages of the two batteries:
1. Different materials:
The reason why it is called "ternary lithium" and "lithium iron phosphate" mainly refers to the chemical elements of the "positive electrode material" of the power battery;
"Ternary lithium":
The cathode material uses lithium nickel cobalt manganate (Li(NiCoMn)O2) ternary cathode material for lithium batteries. This material combines the advantages of lithium cobalt oxide, lithium nickel oxide and lithium manganate, forming a three-phase eutectic system of the three materials. Due to the ternary synergistic effect, its comprehensive performance is better than any single combination compound.
"Lithium iron phosphate":
refers to lithium-ion batteries using lithium iron phosphate as the cathode material. Its characteristics are that it does not contain precious metal elements such as cobalt, the raw material price is low, and the resources of phosphorus and iron are abundant in the earth, so there will be no supply problems.
summary
Ternary lithium materials are scarce and are rising with the rapid development of electric vehicles. Their prices are high and they are highly restricted by upstream raw materials. This is a characteristic of ternary lithium at present;
Lithium iron phosphate, because it uses a lower ratio of rare/precious metals and is mainly cheap and abundant iron, is cheaper than ternary lithium batteries and is less affected by upstream raw materials. This is its characteristic.
2. Different energy densities:
"Ternary lithium battery": Due to the use of more active metal elements, the energy density of mainstream ternary lithium batteries is generally (140wh/kg~160 wh/kg), which is lower than that of ternary batteries with high nickel ratio (160 wh/ kg～180 wh/kg); some weight energy density can reach 180Wh-240Wh/kg.
"Lithium iron phosphate": The energy density is generally 90-110 W/kg; some innovative lithium iron phosphate batteries, such as blade batteries, have an energy density of up to 120W/kg-140W/kg.
summary
The biggest advantage of "ternary lithium battery" over "lithium iron phosphate" is its high energy density and fast charging speed.
3. Different temperature adaptability:
Low-temperature resistance:
Ternary lithium battery: Ternary lithium battery has excellent low-temperature performance and can maintain about 70%~80% of normal battery capacity at -20°C.
Lithium iron phosphate: Not resistant to low temperatures: When the temperature is below -10°C,
lithium iron phosphate batteries decay very quickly. Lithium iron phosphate batteries can only maintain about 50% to 60% of normal battery capacity at -20°C.
summary
There is a big difference in temperature adaptability between "ternary lithium battery" and "lithium iron phosphate"; "lithium iron phosphate" is more resistant to high temperatures; and the low-temperature-resistant "ternary lithium battery" has better battery life in northern areas or winter.
4. Different life spans:
If the remaining capacity/initial capacity = 80% is used as the test end point, test:
Lithium iron phosphate battery packs have a longer cycle life than lead-acid batteries and ternary lithium batteries. The "longest life" of our vehicle-mounted lead-acid batteries is only about 300 times; the ternary lithium battery can theoretically last up to 2,000 times, but in actual use, the capacity will decay to 60% after about 1,000 times; and the real life of lithium iron phosphate batteries is 2000 times, there is still 95% capacity at this time, and its conceptual cycle life reaches more than 3000 times.
summary
Power batteries are the technological pinnacle of batteries. Both types of lithium batteries are relatively durable. Theoretically speaking, the lifespan of a ternary lithium battery is 2,000 charge and discharge cycles. Even if we charge it once a day, it can last for more than 5 years.
5. Prices are different:
Since lithium iron phosphate batteries do not contain precious metal materials, the cost of raw materials can be reduced very low. Ternary lithium batteries use lithium nickel cobalt manganate as the positive electrode material and graphite as the negative electrode material, so the cost is much more expensive than lithium iron phosphate batteries.
The ternary lithium battery mainly uses the ternary cathode material of "lithium nickel cobalt manganate" or "lithium nickel cobalt aluminate" as the positive electrode, mainly using nickel salt, cobalt salt, and manganese salt as raw materials. The "cobalt element" in these two cathode materials is a precious metal. According to data from relevant websites, the domestic reference price of cobalt metal is 413,000 yuan/ton, and with the reduction of materials, the price continues to rise. At present, the cost of ternary lithium batteries is 0.85-1 yuan/wh, and it is currently rising with market demand; the cost of lithium iron phosphate batteries that do not contain precious metal elements is only about 0.58-0.6 yuan/wh.
summary
Since "lithium iron phosphate" does not contain precious metals such as cobalt, its price is only 0.5-0.7 times that of ternary lithium batteries; cheap price is a major advantage of lithium iron phosphate.
Summarize
The reason why electric vehicles have flourished in recent years and represent the future direction of automobile development, giving consumers an increasingly better experience, is largely due to the continuous development of power battery technology.
Post time: Oct-28-2023
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