How long is the three-way lithium electric life cycle? Theoretical life is only average.

As the range of new energy vehicles is limited, how to improve their endurance has affected the entire market. In the battery industry, ternary lithium batteries quickly occupied the 3C, automotive and other markets with many advantages, and gradually replaced traditional lead-acid batteries. For traditional batteries, lithium ternary batteries have a long life, energy conservation, environmental protection, and no pollution, low maintenance costs, complete charging and discharging, lightweight, and other advantages. In some promotional materials, some people think that lithium ternary batteries have a long life. Is it really so? How many times does it have a life cycle? Let us uncover the truth.

What is a three-way lithium battery?

In nature, lithium is the lightest metal with the smallest atomic mass. Lithium is chemically active and easily loses electrons to be oxidized to Li +. The standard electrode potential is -3.045 V and the electrochemical equivalent is 0.26 g/Ah. These characteristics of lithium determine that it is a material with high specific energy. Lithium ternary batteries refer to lithium secondary batteries that use three transition metal oxides of nickel cobalt manganese as positive electrode materials. It fully integrates the good cyclic performance of lithium cobalt acid, the high specific capacity of lithium nickel acid, and the high security and low cost of lithium manganese acid. The synthesis of multi-element composite lithium inlay oxides such as nickel cobalt manganese by molecular level mixing, doping, coating, and surface modification is a lithium-ion rechargeable battery that has been widely studied and applied.

Theoretical life is only average.

Lithium ternary battery life is calculated after the use to a certain extent, the capacity attenuation ratio, directly to the capacity life is zero termination. In the industry, the algorithm is generally a three-way lithium battery full of electricity after discharge, which is called cycle life. During use, irreversible chemical reactions within a lithium battery can cause a reduction in battery capacities, such as improper use, or use at very high or very low temperatures. For example, the decomposition of the electrolyte, the inactivation of the active material, the collapse of the positive and negative polar structures, and the reduction of the number of lithium ions embedded and deem bedded. Experiments have shown that higher power discharge will lead to faster attenuation of capacity. If the discharge current is low, the battery voltage will be close to the equilibrium voltage and can release more energy.

The theoretical life of the three-part lithium battery is 1200 full charge and discharge, which is the complete cycle life. According to the frequency of use, it is fully charged and discharged once every three days, 120 full charge and discharge times a year, and the service life of the three-part lithium battery reach ten years. Even if there is a loss or reduction in the number of days of charging and discharging during use, it can reach eight years. Note that this refers to capacity life. After eight years, the capacity of the three-part lithium battery will have more than 60 %. This is the standard.

The theoretical life of ternary lithium batteries is medium in commercial rechargeable lithium batteries. lithium iron phosphate is about 2,000 times, while lithium titanate is said to reach 10,000 cycles. At present, mainstream battery manufacturers have promised more than 500 times in their three-way core specifications(charged and discharged under standard conditions), but due to consistency problems, the voltage and internal resistance cannot be completely the same. Its cycle life is about 400 times. The manufacturer recommends that the SOC use a window of 10 % to 90 %. It is not recommended to carry out deep charging and discharging. Otherwise, it will cause irreversible damage to the positive and negative polar structure of the battery. If it is calculated in shallow charge, the cycle life will be at least 1,000 times. In addition, if lithium batteries are often discharged at high magnification and high temperature, the battery life will drop significantly to less than 200 times.

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