With the promotion of energy conservation and environmental protection, more and more environmentally friendly products are applied to the market. In the battery industry, ternary lithium batteries occupy the market rapidly with many advantages, and gradually replace the traditional lead-acid battery. For traditional batteries, ternary lithium batteries have long life, energy saving, environmental protection, no pollution, low maintenance cost, complete charge and discharge, light weight and so on. It is always said that ternary lithium batteries have long life, to what extent?
Ternary lithium battery
What are ternary lithium batteries?
In nature, lithium is the lightest and smallest metal with an atomic weight of 6.94g/mol, ρ=0.53g/cm3. Lithium has active chemical properties and is easy to lose electrons and be oxidized to Li+. Therefore, the standard electrode potential is * negative, which is -3.045V, and the electrochemical equivalent is * small, which is 0.26g/Ah. These characteristics of lithium determine that it is a material with very high specific energy. Ternary lithium battery refers to lithium secondary battery with ni, Co and Mn transition metal oxides as cathode materials. It fully integrated the good cycling performance of lithium cobalate, high specific capacity of lithium nickelate, high safety and low cost of lithium manganese, and synthesized the synergistic composite lithium embedded oxides of nickel, cobalt and manganese by means of molecular level mixing, doping, coating and surface modification. It is a kind of lithium ion rechargeable battery which is widely studied and applied at present.
Ternary lithium battery life
The so-called lithium battery life refers to the battery after a period of use, capacity attenuation to 70% of the nominal capacity (room temperature 25℃, standard atmospheric pressure, and 0.2c discharge battery capacity), can be regarded as the end of life. In the industry, the cycle life of lithium battery is calculated by the cycle times of full discharge. In the process of use, irreversible electrochemical reactions will occur in the lithium battery to reduce the capacity, such as the decomposition of electrolyte, the inactivation of active materials, and the collapse of positive and negative electrode structures to reduce the number of lithium ions embedded and unembedded. Experiments show that higher discharge rate will lead to faster capacity decay, if the discharge current is low, the battery voltage will be close to equilibrium voltage, can release more energy.
The theoretical life of ternary lithium battery is about 800 cycles, which is in the middle of commercial rechargeable lithium battery. Lithium iron phosphate is about 2,000 cycles, while lithium titanate is said to reach 10,000 cycles. At present, the mainstream battery manufacturers in its production of three core specifications committed more than 500 times (under standard conditions of charge and discharge), but the core in the battery pack, due to consistency problems, mainly voltage and internal resistance can not be exactly the same, its cycle life is about 400 times. The manufacturer recommends that the SOC use window be 10%~90%. It is not recommended to carry out deep charge and discharge, otherwise it will cause irreversible damage to the positive and negative electrode structure of the battery. If calculated by shallow charge and shallow discharge, the cycle life will be at least 1000 times. In addition, if lithium-ion batteries are frequently charged at high power rates and high temperatures, their battery life drops to less than 200 times.
The life cycle times of lithium batteries are determined according to battery quality and battery materials:
1. The cycle times of ternary materials are about 800 times.
2. The cycle times of lithium iron phosphate battery are about 2500 times.
3, there is a difference between the number of genuine battery and defective battery cycle. The genuine battery is designed and produced according to the cycle number of battery manufacturer specifications, and the number of defective battery cycle may sometimes be less than 50 times.
Ternary lithium battery life
The so-called lithium battery life refers to the battery after a period of use, capacity attenuation to 70% of the nominal capacity (room temperature 25℃, standard atmospheric pressure, and 0.2c discharge battery capacity), can be regarded as the end of life. In the industry, the cycle life of lithium battery is calculated by the cycle times of full discharge. In the process of use, irreversible electrochemical reactions will occur in the lithium battery to reduce the capacity, such as the decomposition of electrolyte, the inactivation of active materials, and the collapse of positive and negative electrode structures to reduce the number of lithium ions embedded and unembedded. Experiments show that higher discharge rate will lead to faster capacity decay, if the discharge current is low, the battery voltage will be close to equilibrium voltage, can release more energy.
The theoretical life of ternary lithium battery is about 800 cycles, which is in the middle of commercial rechargeable lithium battery. Lithium iron phosphate is about 2,000 cycles, while lithium titanate is said to reach 10,000 cycles. At present, the mainstream battery manufacturers in its production of three core specifications committed more than 500 times (under standard conditions of charge and discharge), but the core in the battery pack, due to consistency problems, mainly voltage and internal resistance can not be exactly the same, its cycle life is about 400 times. The manufacturer recommends that the SOC use window be 10%~90%. It is not recommended to carry out deep charge and discharge, otherwise it will cause irreversible damage to the positive and negative electrode structure of the battery. If calculated by shallow charge and shallow discharge, the cycle life will be at least 1000 times. In addition, if lithium-ion batteries are frequently charged at high power rates and high temperatures, their battery life drops to less than 200 times.
In a relatively balanced capacity and safety of materials, good cycle performance in normal cobalt acid lithium, early due to technical reasons the nominal voltage is only 3.5 3.6 V, limited in scope, but so far, as incremental improvements were made in the formulation and perfect structure, nominal voltage of battery is 3.7 V, on the capacity has been reached or exceed cobalt acid lithium battery level.
1. High voltage platform. Voltage platform is an important index of battery energy density, which determines the basic efficiency and cost of battery, so it is of great significance to the selection of battery materials. The higher the voltage platform, the greater the specific capacity, certainly the same volume, weight, and even the same hour of the battery, the voltage platform is higher than the ternary material lithium battery longer mileage. The ternary material has a significantly higher voltage platform than lithium iron phosphate, with a high line of 4.2 VOLTS and a discharge platform of 3.6 or 3.7 volts.
2. High energy density
3. High vibration density
