Rechargeable Li-Po Battery 3.7V 1000mAh in Pakistan Lithium-ion Battery more correctly lithium-ion battery is a rechargeable battery of lithium-ion technology using a polymer electrolyte instead of a liquid one. High conductivity semisolid (gel) polymers form this electrolyte. These batteries provide higher specific energy than other lithium battery types and are being used in applications where weight is a critical feature – like tablet computers, cellular telephone handsets or radio-controlled aircraft.