On the left you can see two Lithium Ion Polymer cells. On the right, two packs made of cylindrical Lithium Ion batteries
Lithium Ion cells tend to be either rectangular or cylindrial. They are hard-shelled with a strong casing. They often weigh a little more and come in larger capacity but they are also more sturdy and are hard to puncture. They're often used for laptop batteries and other big packs. These are often called:
- Lithium Ion
- LiCo (lithium cobalt, the anode chemistry)
Lithium Ion Polymer cells tend to be thin rectangles in a silvery bag. They are soft-shelled and have an easy to damage casing. They often weigh a little less and come in smaller capacity. You can fit them into smaller devices such as tiny iPods. These are often called:
- Lithium Ion Polymer
Despite the structural differences, you should treat them similarly and consider them two versions ('gentle and light' 'tough and strong') of the same kind of battery.