Li-ion batteries also have certain fundamental advantages over traditional battery chemistries like Ni-Cd, Ni-Mh and Pb-acid. Lithium has the lowest reduction potential among all of the elements, this in turn results in Li-ion batteries having the highest cell potential. Lithium is the third lightest element and has a small ionic radius. This results in Li-ion batteries having high gravimetric and volumetric capacity and power density. Other advantages include a slow selfdischarge rate, high columbic efficiency, fast charging and discharging, and a long life cycle. Figure shows that LIBs have the highest energy density (150-200Wh/kg) and high power density (10-104 W/kg) among all the available battery chemistries. Today imagining a world without Li-ion batteries is almost impossible. Li-ion batteries are currently used in multiple domains including mobility applications such as electric vehicles and storage applications like electrical grids and energy harvesting from renewable sources like wind, solar and geothermal. They also find applications in niche domains such as portable electronics and wireless communications.