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With the implementation of environmental protection and energy policies, new energy vehicles have developed rapidly, and a large number of new energy vehicle manufacturers have emerged on the market, and new energy vehicles have gradually become a rookie in the market. At present, for new energy vehicles, the market mainly cares about three issues: battery life, charging And safety, the key to these three problems lies in the core component of new energy vehicles - the battery. Classification of batteries According to the type: chemical, physical and biological batteries, if according to the structure, it can be divided into two categories: battery and fuel cell. In terms of type, the current new energy batteries on the market are all chemical batteries, and there are five common types of power batteries: lead-acid, lithium titanate, lithium cobalt oxide, lithium iron phosphate, nickel-cobalt-manganese, and nickel-cobalt-aluminum. The most widely circulated on the market are lithium iron phosphate and ternary lithium batteries. These two batteries have higher energy density and more stable performance, and are the mainstream choices for new energy vehicles. So let's talk about the difference between the two batteries. 01 Lithium iron phosphate battery It refers to the lithium-ion battery using lithium iron phosphate as the positive electrode material. It was born in the 1990s. Professor John Goodenough of the University of Texas led A.K.Padhi and others to find that lithium iron phosphate has the characteristics of reversibly moving in and out of lithium. It is a relatively mature product. The battery has the advantages of high safety, long service life and low manufacturing cost. At present, BYD, the leading enterprise in the new energy industry, was the first to start with lithium iron phosphate, and it has indeed achieved extraordinary achievements, making it almost far ahead in the field of electric vehicles. 02 Ternary lithium battery It refers to a lithium battery with a ternary positive electrode material using nickel cobalt lithium manganate (Li(NiCoMn)O2) or nickel cobalt aluminum aluminate as the positive electrode material. The ternary composite positive electrode material is made of nickel salt, cobalt salt and manganese salt as raw materials. It is a new type of battery that has been vigorously developed in the recent stage. Compared with lithium iron phosphate batteries, the biggest advantage is high energy density, and energy density is an important indicator for evaluating battery performance. Generally speaking, the higher the energy density, the higher the electric energy contained in the battery per unit weight or volume, and the longer the cruising range can be provided for the vehicle. Because of its inherent chemical properties, lithium iron phosphate batteries have a low voltage and an energy density of about 140Wh/kg; while ternary lithium batteries have a high voltage and an energy density of 240kWh/kg. That is to say, under the same battery weight, the energy density of ternary lithium is 1.7 times that of lithium iron phosphate battery. Lithium iron phosphate is better than ternary lithium battery. Because of material reasons, lithium iron phosphate battery has the best thermal stability. The electric heating peak is greater than 350 °C. When the temperature is 500-600 °C, the internal chemical composition will begin to decompose. The ternary lithium battery material is unstable, and is often prone to decomposition at around 200 degrees, and the electrolyte will burn rapidly under the action of high temperature, causing a chain reaction, and even causing the vehicle to spontaneously ignite. low temperature The performance of ternary lithium battery is better than that of lithium iron phosphate battery, especially in the north where the temperature is low in winter, the performance of ternary lithium battery is even better. Battery Life The number of complete charge and discharge cycles of a lithium iron phosphate battery can reach 3,500 times. After each charge and discharge, the power decays once. The conversion time is about 10 years. The ternary lithium battery has a shorter lifespan than lithium iron phosphate, and the full charge and discharge cycle exceeds more than 10 years. Attenuation will begin to occur after 2000 times, which is about 10 years when converted into time. manufacturing cost The ternary lithium battery is larger than the lithium iron phosphate battery. The ternary lithium battery uses a variety of materials of nickel, cobalt and manganese, and the production of high nickel batteries requires a relatively strict process environment, and the current cost is relatively high. The production of lithium iron phosphate batteries does not require precious metals, so the cost is more advantageous. To sum up, lithium iron phosphate and ternary lithium batteries have their own advantages, and it is difficult to define who is more suitable for future development. Tesla is already researching solid-state batteries. Combining advantages and correcting shortcomings, the future should belong to solid-state batteries. |
