Lithium polymer battery

Lithium polymer battery

A lithium polymer battery used to power a smartphone.
Specific energy	100–265 W·h/kg (0.36–0.95 MJ/kg)[1]
Energy density	250–670 W·h/L (0.90–2.63 MJ/L)[1]

A lithium polymer battery, or more correctly, lithium-ion polymer battery (abbreviated as LiPo, LIP, Li-poly, lithium-poly, and others), is a rechargeable battery derived from lithium-ion and lithium-metal battery technology. The primary difference is that instead of using a liquid Lithium salt (such as lithium hexafluorophosphate, LiPF₆) held in an organic solvent (such as EC/DMC/DEC) as the electrolyte, the battery uses a solid (or semi-solid) polymer electrolyte such as polyethylene glycol (PEG), polyacrylonitrile (PAN), poly(methyl methacrylate) (PMMA) or poly(vinylidene fluoride) (PVdF). Other terms used in the literature for this system include hybrid polymer electrolyte (HPE), where "hybrid" denotes the combination of the polymer matrix, the liquid solvent, and the salt.^[2]

Polymer electrolytes can be divided into two large categories: dry solid polymer electrolytes (SPE) and gel polymer electrolytes (GPE).^[3]

In comparison to liquid electrolytes and solid organic electrolytes, polymer electrolytes offer advantages such as increased resistance to variations in the volume of the electrodes throughout the charge and discharge processes, improved safety features, excellent flexibility, and processability. These batteries provide higher specific energy than other lithium battery types.

They are used in applications where weight is critical, such as laptop computers, tablets, smartphones, radio-controlled aircraft, and some electric vehicles.^[4]