1, 18650 battery is cylindrical, internal liquid, because battery design and materials, 18650 is suitable for high current, so almost all notebooks are designed with 18650 batteries, electric vehicles ;Only super notebook, because energy saving, so cannot use 18650 batteries and to use polymer lithium battery, especially the tablet PC, etc; Digital camera flash for charging and discharging need big voltage and instantaneous electric current, so can only use 18650 similar battery, the volume is a little small;2 advantages, polymer lithium battery, small size, large capacity, the disadvantage is that life is shorter than the 18650, because of using different design and material, some internal liquid, some are dry or is colloid, and large current discharge performance is better than 18650 cylindrical battery, so I need the large capacity electric equipment of small volume, often use lithium polymer batteries, the most typical is the performance of the mobile phone, tablets and other devices.