"Lithium-polymer batteries tend to hold a charge better and longer, but at a higher cost. The charging cycles are greater than with lithium-ion, meaning the “wear” on lithium-polymer is less; after a couple of years of use, the drop in battery use time is minimal so the battery life is near the same amount as new. There are conflicting stories about this, though. This may because of using lithium-ion-polymer hybrid batteries instead since it is safer, cheaper, lighter, and can be shaped differently than lithium-ion batteries; they aren’t as flexible or thin as true lithium-polymer batteries, though. Lithium-polymer batteries are known as explosive batteries since some of the iPhones and other devices that use these types of batteries have caught fire, and almost explosively igniting without warning. As long as proper care of any battery is given, neither battery type is really that much safer than another (HTC HD2’s have had similar ignition problems, and they had lithium-ion batteries)."
http://www.makeuseof.com/answers/is...th-4200-mah-equal-to-li-ion-4200-mah-battery/
http://www.makeuseof.com/answers/is...th-4200-mah-equal-to-li-ion-4200-mah-battery/