Li-poly

Lithium polymer battery

A lithium-ion polymer battery used to power a mobile phone
Specific energy	100–265 W·h/kg(0.36–0.95 MJ/kg)
Energy density	250–730 W·h/L(0.90–2.63 MJ/L)

A lithium polymer battery, or more correctly lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly and others), 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 a 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.

LiPo cells follow the history of lithium-ion and lithium-metal cells which underwent extensive research during the 1980s, reaching a significant milestone with Sony's first commercial cylindrical Li-ion cell in 1991. After that, other packaging forms evolved, including the pouch format now also called "LiPo".

Lithium polymer cells have evolved from lithium-ion and lithium-metal batteries. The primary difference is that instead of using a liquid lithium-salt electrolyte (such as LiPF₆) held in an organic solvent (such as EC/DMC/DEC), the battery uses a solid polymer electrolyte (SPE) such as poly(ethylene oxide) (PEO), poly(acrylonitrile) (PAN), poly(methyl methacrylate) (PMMA) or poly(vinylidene fluoride) (PVdF).