Analysing the Causes of Lithium Battery Aging

Aging generally refers to the placement of the battery after the first charge after assembly, which can be normal temperature aging or high temperature aging, all functions are to make the performance and composition of the SEI film formed after the first charge stable.

The normal temperature aging temperature is 25℃, and the high temperature aging facilities are different, some have 38℃ and 45℃. Between 48 and 72 hours

Aging, sealing two cases:

For batteries that form holes, the relative humidity is controlled below 2% at room temperature, and the sealing effect is better after aging.

For high temperature aging, the sealing aging effect is better.

However, it is certain that there are electrochemical dynamic changes in the ageing process, which are of great help to the stability of the SEI and can promote the stability of the electrochemical system.

The purpose of ageing

In fact, one of the reasons is to make the electrolyte fully infiltrated, the other is the living cathode material some active ingredients through some inactivation reaction, make the whole battery performance more stable performance, many companies in order to make this process faster, using high temperature aging, high temperature aging should pay attention to control the time and temperature, However, due to high temperature aging may occur over normal temperature aging life The degradation effect of the substance, good control, full reflection of the active component, stable battery characteristics and performance, poor control, so the electrical performance decline, low yield, infrared additives, and even leakage and other conditions are very possible.

Battery performance is more stable after high temperature ageing. High temperature ageing is used in the production process of most lithium-ion battery manufacturers. The temperature ranges from 45°C to 50°C and the battery is aged for 1 to 3 days. After high-temperature aging, the potential adverse phenomena of the battery are exposed: such as voltage changes, thickness changes, internal resistance changes, etc., are comprehensive indicators that directly test the safety and electrochemical performance of this batch of batteries.

At present, most battery companies use domestic low-quality diaphragms for mass production, and high-temperature aging has become an unwritten requirement for safety testing of battery internal structures.

High temperature aging is only to shorten the entire production cycle of the battery, the player only enters the battery at high temperature to accelerate the chemical reaction, the battery is not more than the benefits may damage the battery, it is best to incubate at room temperature for more than three weeks, we are negative, the separator, enough electrolyte balance and other chemical reactions, and then the battery performance is more real.

This is often the case with lithium-ion batteries because they can only be charged and discharged a limited number of times, so you should try to fully charge your phone's battery. However, I did find an experimental chart on the charge/discharge cycle of lithium-ion batteries, and the cycle life data is as follows:

Cycle life :10%DOD> 1000 times, 100%DOD cycle life :> 200 times, where DOD is an abbreviation for depth of discharge. As you can see from the table, the rechargeable time is related to the depth of discharge, and the cycle life of 10%DOD is much longer than that of 100%DOD. Of course, when reduced to the actual total charge capacity: 10%*1000=100,100%*200=200.

The latter is still relatively good for full charge and discharge, but there are some corrections to be made: in normal circumstances, you should have a date to recharge the battery when the remaining charge is used up, according to the principle, but if your battery is not expected to last the whole day on the second day, you should start charging in time.