What Actually Affect lithium ion battery cyclelife?
--how many cyclelife of 18650 Battery 3.7v 4400mah?
At the beginning of the use of electric vehicles, the obvious performance of the power battery is it's power dynamic ability and it's navigation ability. As time goes on, the other characteristics of the battery will be gradually shown to us, like battery discharge cycle life or shelf life, and battery internal resistance.
take 18650 3.7v 4400mah NCM rechargable lithium ion battery for example.
during the discharging process, NCM battery internal chemistry will have by-side affection and the serve is crystal metal risen. this is a slow reaction process, will not show immediately. before it's rated lifecylce, this 18650 battery will not stop working. it will keep working with gradually getting worse, with it's capacity 4400mAh gradually drop till die.
therefore, what affects the battery discharge cycle life?
take the 3.7v 4400mah lithium battery discharge at 50-60℃. this is the temperature for highest duration for lithium battery working. electrolyte will be very active to react with anode material NCM, that means, lithium ions are errosing by electrolyte. therefore, crystal structure will be broken.lithium ions will get less and less.
to discharge the battery 3.7v 4400mah 18650 battery at a high discharge rate, heat generated thereafter will cause by-side chemistry reaction. on the other hand, discharge with high C rate, that means battery cathod polarity will loose lithium ions at a very fast speed. that will destroy SIE fim and break the stable state of battery.
at the standard nominated battery cyclfe life, battery mihgt have 1000times cyclelife, but when it discharge at DOD40-70%, you will get 2000-2500times cyclelife.