Editing Lithium polymer battery (section)

== Electrolyte types ==
[[File:Schematic of a lithium polymer battery based on GPEs.jpg|thumb|Schematic of a lithium polymer battery based on GPEs<ref>{{Cite journal |last1=Hoang Huy |first1=Vo Pham |last2=So |first2=Seongjoon |last3=Hur |first3=Jaehyun |date=2021-03-01 |title=Inorganic Fillers in Composite Gel Polymer Electrolytes for High-Performance Lithium and Non-Lithium Polymer Batteries |journal=Nanomaterials |volume=11 |issue=3 |pages=614 |doi=10.3390/nano11030614 |pmid=33804462 |pmc=8001111 |issn=2079-4991|doi-access=free }}</ref>]]

Polymer electrolytes can be divided into two large categories: dry solid polymer electrolytes (SPE) and gel polymer electrolytes (GPE).<ref name=":0">{{Cite journal |last=Mater |first=J |date=2016 |title=Polymer electrolytes for lithium polymer batteries |url=https://pubs-rsc-org.turing.library.northwestern.edu/en/content/articlelanding/2016/ta/c6ta02621d |journal=Journal of Materials Chemistry A |volume=4 |issue=26 |pages=10038–10069 |doi=10.1039/C6TA02621D |via=Royal Society of Chemistry|url-access=subscription }}</ref>

Solid polymer electrolyte was initially defined as a polymer matrix swollen with lithium salts, now called dry solid polymer electrolyte.<ref name=":0" /> Lithium salts are dissolved in the polymer matrix to provide ionic conductivity. Due to its physical phase, there is poor ion transfer, resulting in poor conductivity at room temperature. To improve the ionic conductivity at room temperature, gelled electrolyte is added resulting in the formation of GPEs. GPEs are formed by incorporating an organic liquid electrolyte in the polymer matrix. Liquid electrolyte is entrapped by a small amount of polymer network, hence the properties of GPE is characterized by properties between those of liquid and solid electrolytes.<ref>{{Cite journal |last1=Cho |first1=Yoon‐Gyo |last2=Hwang |first2=Chihyun |last3=Cheong |first3=Do Sol |last4=Kim |first4=Young‐Soo |last5=Song |first5=Hyun‐Kon |date=May 2019 |title=Gel Polymer Electrolytes: Gel/Solid Polymer Electrolytes Characterized by In Situ Gelation or Polymerization for Electrochemical Energy Systems (Adv. Mater. 20/2019) |journal=Advanced Materials |volume=31 |issue=20 |pages=1970144 |doi=10.1002/adma.201970144 |bibcode=2019AdM....3170144C |issn=0935-9648|doi-access=free }}</ref> The conduction mechanism is similar for liquid electrolytes and polymer gels, but GPEs have higher thermal stability and a low volatile nature which also further contribute to safety.<ref>{{Citation |last1=Naskar |first1=Anway |title=Polymer-Ceramic Composite Electrolyte for Li-Ion Batteries |date=2022 |pages=1031–1039 |url=http://dx.doi.org/10.1016/b978-0-12-820352-1.00123-1 |access-date=2022-11-22 |publisher=Elsevier |doi=10.1016/b978-0-12-820352-1.00123-1 |isbn=9780128232910 |s2cid=241881975 |last2=Ghosh |first2=Arkajit |last3=Roy |first3=Avinava |last4=Chattopadhyay |first4=Kinnor |last5=Ghosh |first5=Manojit |url-access=subscription |encyclopedia=Encyclopedia of Materials: Plastics and Polymers}}</ref>