Apparently there is some debate about that, but I understand the differences now that you made me do more homework. LOL
Lithium-Ion Batteries began their development in 1912. However, they did not become popular until they were adopted by Sony in 1991. Lithium Ion Batteries have high energy-densities and cost less than lithium-polymer batteries. In addition, they do not require priming when first used and have a low self-discharge. However, lithium-ion batteries do suffer from aging – even when not in use.
Lithium-polymer batteries can be dated back to the 1970’s. Their first design included a dry solid polymer electrolyte that resembled a plastic film. Therefore, this type of battery can result in credit card thin designs while still holding relatively good battery life. In addition, lithium-polymer batteries are very lightweight and have improved safety. However, these batteries will cost more to manufacture and have a worse energy density than lithium-ion batteries.