During charge, the ions move in the direction of the negative electrode and during discharge, they move in the direction of the positive electrode.
Lithium-ion batteries are lighter and offer far more energy density that their predecessors, nickel-cadmium batteries.
Lithium-ion is, essentially, live chemistry inside your phone.
Every lithium-ion battery is made of sheets of positive (lithium cobalt oxide) and negative electrodes (carbon), with perforated separators between them, wound in tight, overlapping spirals.
Apple won’t comment about what’s going on with the i Phone's rechargeable lithium-ion batteries or the i OS software that manages them, and it hasn't acknowledged any issue beyond unexpected shutdowns on some i Phones. Top 1 after I barely used my i Phone6, bottom a min after plugging into a charger. pic.twitter.com/0n Sc Zmkqy T — Lance Ulanoff (@Lance Ulanoff) January 24, 2017 However, late last year Apple did reveal that a small number of i Phone 6S devices manufactured between September and October 2015 had a battery issue and were eligible for free battery replacement.
Then in December, and only on the Chinese version of its support site, Apple announced that there were some phones “outside the affected range” of phones that they knew had a battery defect that were also shutting down.
Going back to the i Phone 5S and i OS 7.1, users recounted rapid battery drains.
How you drain and recharge the battery also impacts battery life.Lithium-ion batteries will last longer if they're never fully charged or recharged (this is why, when you buy a battery-powered gadget like a smartphone, it typically ships with about 50% charge, plus or minus 20%).Side reactions in the chemistry increase when you drain the battery to 0% and constantly recharge to 100%.They include battery-percentage free falls, where you can watch your battery life drain from, say, 30% to zero in the space of a few minutes or suddenly shut down with 20-30% battery life remaining.There's also the perplexing sudden supercharge, like I described at the outset: The battery demands to be charged only to show hearty available battery life as soon as you plug it in.