Inquiry, what are the reasons for affecting the lithium battery pack cycle life?

　　Author ：Iflowpower – Portable Power Station Supplier

What is the cause of the lithium-ion battery pack cycle life? Lithium-ion battery is a new battery that can extend the battery capacity in recent years, but after multiple cycle charge and discharge cycles, the battery capacity will decrease in performance. The faster the battery capacity at the same conditions, the battery quality is relatively poor. The cycle performance of lithium-ion battery packs is an important indicator of its quality.

Many of the standards related to the lithium-ion battery packs have cycle life. The lithium-ion battery pack charging circulation process is a complex physical chemical reaction process, which affects the factors of cycle life. The following is an analysis of factors affecting the life of lithium ion battery pack.

1. Design and manufacturing processes in battery design, material choice is the most important factor. Different material performance characteristics are different, and the performance of the battery developed has a gap.

The cycle performance of the positive and negative material matches is good, and the battery's cycle life will be long. In general, the design assembly process generally requires the negative electrode capacity to relatively excessively excessive, if not, the negative electrode will precipitate lithium during charging, forming a lithium branch crystal to affect safety. The negative electrode is too much relative to the positive electrode, and the positive electrode may excessively deepen, resulting in structural collapse.

The types and stocks of the electrolyte also affect battery life. The manufacturing process flow of lithium-ion battery packs is important to: positive and negative ingredients, coating, production, winding, housing, niche, sealing, chemical formation. During battery production, the process of each step is very strict.

Any process is not controlled, it is possible to affect battery cycle performance. 2, the process of aging the lithium-ion battery material aging decline the lithium ion battery pack charging circulation is a process of retreating, moving between the lithium ion through the electrolyte in the positive and negative material. In the lithium-ion battery pack circulation, there is still a large number of side reactions in addition to the redox reaction in the positive and negative electrode.

If the side reactions of the lithium ion battery can be lowered to a low level, the lithium ions can always be smoothly traveling to and from the positive and negative material through the electrolyte, and the cycle life of the lithium ion battery can be added. The nature of the positive and negative concentration fluid can also affect the capacity of the battery and the life of the cycle. Lithium-ion battery pack is positive, and the general electrode commonly used current collective material is aluminum and copper, both are easy to corrode metal materials.

The collective body is formed to form a passivation film, the adhesiveness, and local corrosion (pixabograph) and comprehensive corrosion will increase the internal resistance of the battery, resulting in reduced capacity loss and discharge efficiency. It can enhance its adhesion and corrosion resistance by acid-alkaline etching, conductive coating, etc. 3.

The process of charging and discharge system, the process of charge and discharge system, the process of charge and discharge cycle, the size of the charge and discharge current, the selection of charge and discharge cutout voltage and the use of a charge and discharge method such as charging and discharge system, for the lithium ion battery The cycle life also has a very important impact. Anyone who blindly increases the operating current of the battery, adding charging cutoff voltage, reducing discharge cutoff, etc., will reduce lithium ion battery pack performance.

The charge and discharge shut-off voltage of the lithium-ion battery of different electrochemical systems is different. In the charging process of the lithium-ion battery, the ultra-charge shutdown voltage is considered to be overcharge. When the lithium ion battery is overcharge, excess lithium ions from the positive electrode will deposit or embedded onto the negative electrode, the deposited active lithium is easily reacted, and the heat is released to increase the temperature of the battery.

When the discharge voltage of the lithium ion battery is below the discharge cutoff voltage, an over-discharge is formed. During over-discharge, lithium ions will overrun from the negative electrode, and then embedded in the next charging. The discharge capacity of the lithium-ion battery after over-discharge is over-discharged, and the charge and discharge efficiency is reduced.

In addition, the lithium-ion battery may be blown under large current conditions, and the device element may be damaged. 4. The use of lithium-ion batteries use environmental lithium-ion battery packs is also very important for its cycle life.

Among them, ambient temperature is very important factor. The ambient temperature is too low or too high will affect the cycle life of the lithium-ion battery. Conventional lithium-ion battery operating temperature: -20 ¡ã C ~ 60 ¡ã C, but generally lower than 0 ¡ã C, the lithium ion battery performance will decrease, and the discharge capacity will reduce it, so the lithium ion battery performance is completely working temperature, common is 0 ~ 40 ¡ã C.

Some special environmental requirements of the lithium-ion battery temperature is different, and also pay attention to the ventilation, facilitating heat dissipation, and maintaining the clean environment. The charge and discharge cycle of the lithium-ion battery is unstable, high temperature results in the electrode electrochemical polarization of the battery and the emergence of the gas, causing the blocked phenomenon, and the new charge transmission resistance is added, and the kinetic performance of ion transmission is lowered. The constant pressure charging time is added, and charging performance is also deteriorated.

Using a lithium-ion battery in the case of transportation or normal operation, it is possible to experience the test of vibration, impact, collision and other conditions. Some lithium ion batteries are charged and discharged when communicating with the system and receives data information according to a certain frequency. Factors affecting the lithium-ion battery pack cycle life is multifaceted.

The application of lithium-ion batteries is increasing, and the demand for lithium-ion batteries has higher requirements in quantity and quality. The cycle life directly affects the use time and quality of the lithium-ion battery, so the manufacturer's research on its influencing factors is necess.