Types of Batteries:
Nickel Cadmium ( NiCad ) batteries were being used earlier, and now the Lithium based have taken over.
Lithium-Ion Battery: These were the earliest incarnations of Lithium based batteries, where intercalated lithium compound is used as one of the electrode. These are the most popular ones in rechargeable family and they have high energy density, meaning these batteries run longer, in one charge, than the other conventional ones.
Li-Ion batteries are also low self-discharging – this means that even if you put it away on the shelf for more than a month without using it, it would not loose much energy because of low self discharge and hence longer battery life per charge.
When there is a physical damage to the battery, it poses safety risks since the contained electrolyte is inflammable.
Lithium Polymer Battery: Lithium Polymer, or LiPo in short, could be called as a second generation of Lithium based batteries. These uses a solid polymer electrolyte like poly ethylene oxide or one of the related variants. LiPo are light in weight which makes them a better choice, especially for air borne vehicles, since an amount of payload is one of the crucial parameters for drones.
Just like Li-Ion, LiPo also is very low on self-discharge and also has high energy density. LiPo batteries are safer than their ion counterparts as LiPo comes with protection circuit called PCM and this gives protection against overcharging.
Lithium Metal Battery
: There has been a lot of research in the area of energy storage mechanisms and systems, and batteries are no expection to this. A recent MIT news
suggested that a new Lithium metal batteries could double the storage capacity, for the same size as that of LiPo or ion based ones.
On the same note, a tech startup is on its way to commercialize the Lithium metal batteries and these might hit the stores in few months. So, time is not far when LiPo batteries might fade away into the past too. But until then, we need to stick to these as they are the best in the market as of today.