Editing Lithium polymer battery

{{short description|Lithium-ion battery using a polymer electrolyte}}
{{Redirect2|Li-Po|LiPo||Li Po (disambiguation)}}
{{ infobox battery
| image = File:Li-Po Battery from an iPhone 4.jpg
| EtoW  = {{nowrap|100–265 [[Watt hour|W·h]]/[[kg]]}} {{nowrap|(0.36–0.95 MJ/kg)}}<ref name="Lithium-Ion Battery">{{Cite web|title=Lithium-Ion Battery|url=https://www.cei.washington.edu/education/science-of-solar/battery-technology/|access-date=2022-01-06|website=Clean Energy Institute|language=en-US}}</ref>
| EtoS  = {{nowrap|250–670 [[Watt hour|W·h]]/[[Liter|L]]}} {{nowrap|(0.90–2.63 MJ/L)}}<ref name="Lithium-Ion Battery"/>|caption=A lithium polymer battery used to power a [[smartphone]].
}}

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 battery|lithium-ion]] and [[lithium-metal battery]] technology. The primary difference is that instead of using a liquid [[Lithium salt]] (such as [[lithium hexafluorophosphate]], LiPF<sub>6</sub>) held in an [[organic solvent]] (such as [[Ethylene carbonate|EC]]/[[Dimethyl carbonate|DMC]]/[[Diethyl carbonate|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 [[Polyvinylidene fluoride|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.<ref name="Nature_01">{{cite journal |last1=Tarascon |first1=Jean-Marie |author-link1 =Jean-Marie Tarascon |last2=Armand |first2=Michele |date=2001 |title=Issues and challenges facing rechargeable lithium batteries |journal=Nature |volume=414 |issue=6861 |pages=359–367|doi=10.1038/35104644 |pmid=11713543|bibcode=2001Natur.414..359T |s2cid=2468398 }}</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>

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 computer]]s, [[tablet computer|tablets]], [[smartphone]]s, [[radio-controlled aircraft]], and some [[electric vehicle]]s.<ref>Bruno Scrosati, K. M. Abraham, Walter A. van Schalkwijk, Jusef Hassoun (ed), ''Lithium Batteries: Advanced Technologies and Applications'', John Wiley & Sons, 2013 {{ISBN|1118615395}},page 44</ref>

== History ==
{{main|Lithium-ion battery#History}}

The dry SPE was the first used in prototype batteries, around 1978 by [[Michel Armand]],<ref name="Armand">{{cite book| chapter=Extended Abstracts |author1=M. B. Armand |author2=J. M. Chabagno |author3=M. Duclot |title=Second International Meeting on Solid Electrolytes |place=St. Andrews, Scotland |date=20–22 September 1978}}</ref><ref name="Armand_2">{{cite book| chapter=Poly-ethers as solid electrolytes |author1=M. B. Armand, J. M. Chabagno |author2=M. Duclot |name-list-style=amp|title=Fast ion Transport in Solids. Electrodes and Electrolytes |editor1=P. Vashitshta |editor2=J.N. Mundy |editor3=G.K. Shenoy |publisher=North Holland Publishers, Amsterdam |date=1979}}</ref> and 1985 by ANVAR and Elf Aquitaine of France, and [[Hydro-Québec]] of Canada.<ref name="poly_history">{{cite journal |journal=Electrochimica Acta |volume=45 |issue=8–9 |date=3 January 2000 |pages=1501–1508 |title=An overview of the research and development of solid polymer electrolyte batteries |last1=Murata |first1=Kazuo |last2=Izuchi |first2=Shuichi |last3=Yoshihisa |first3=Youetsu |doi=10.1016/S0013-4686(99)00365-5}}</ref>

Nishi mentions that [[Sony]] started research on lithium-ion cells with gelled polymer electrolytes (GPE) in 1988, before the commercialisation of the liquid-electrolyte lithium-ion cell in 1991.<ref name="book_6">{{cite book |editor-last1=Yoshio |editor-first1=Masaki |editor-last2=Brodd |editor-first2=Ralph J. |editor-last3=Kozawa |editor-first3=Akiya |title=Lithium-ion batteries |publisher=Springer |date=2009 |isbn=978-0-387-34444-7 |doi=10.1007/978-0-387-34445-4|bibcode=2009liba.book.....Y }}</ref> At that time, polymer batteries were promising, and it seemed polymer electrolytes would become indispensable.<ref name="book_5">{{cite book |last=Nishi |first=Yoshio |title=Advances in Lithium-ion batteries |editor-last1=van Schalkwijk |editor-first1=Walter A. |editor-last2=Scrosati |editor-first2=Bruno |publisher=Kluwer Academic Publishers |date=2002 |chapter=Chapter 7: Lithium-Ion Secondary batteries with gelled polymer electrolytes |isbn=0-306-47356-9}}</ref> Eventually, this type of cell went into the market in 1998.<ref name="book_6"/> However, Scrosati argues that, in the strictest sense, gelled membranes cannot be classified as "true" polymer electrolytes but rather as hybrid systems where the liquid phases are contained within the polymer matrix.<ref name="book_3">{{cite book |last=Scrosati |first=Bruno |title=Advances in Lithium-ion batteries |editor-last1=van Schalkwijk |editor-first1=Walter A. |editor-last2=Scrosati |editor-first2=Bruno |publisher=Kluwer Academic Publishers |date=2002 |chapter=Chapter 8: Lithium polymer electrolytes |isbn=0-306-47356-9}}</ref> Although these polymer electrolytes may be dry to the touch, they can still include 30% to 50% liquid solvent.<ref name="book_4">{{cite book |last=Brodd |first=Ralf J. |title=Advances in Lithium-ion batteries |editor-last1=van Schalkwijk |editor-first1=Walter A. |editor-last2=Scrosati |editor-first2=Bruno |publisher=Kluwer Academic Publishers |date=2002 |chapter=Chapter 9: Lithium-Ion cell production processes |isbn=0-306-47356-9}}</ref>

Since 1990, several organisations, such as Mead and Valence in the United States and [[GS Yuasa]] in Japan, have developed batteries using gelled SPEs.<ref name="poly_history"/>

In 1996, [[Bellcore]] in the United States announced a rechargeable lithium polymer cell using porous SPE,<ref name="poly_history"/><ref>{{cite journal |last1=Tarascon |first1=J.-M.|author-link1 =Jean-Marie Tarascon |last2=Gozdz |first2=A. S. |last3=Schmutz |first3=C. |last4=Shokoohi |first4=F. |last5=Warren |first5=P. C. |date=July 1996 |title=Performance of Bellcore's plastic rechargeable Li-ion batteries |journal=Solid State Ionics |volume=86-88 |issue=Part 1 |pages=49–54 |publisher=Elsevier |doi=10.1016/0167-2738(96)00330-X}}</ref> which was called a "plastic" lithium-ion cell (PLiON) and subsequently commercialised in 1999.<ref name="Nature_01"/>

== Working principle ==
{{main|Lithium-ion battery#Electrochemistry}}

Like other lithium-ion cells, LiPos operate based on the intercalation and de-intercalation of lithium ions between a positive and a negative electrode. However, instead of a liquid electrolyte, LiPos typically use a gelled or solid polymer-based electrolyte as the conductive medium. A microporous polymer separator is used to prevent direct contact between the electrodes, while still allowing lithium-ion transport.<ref>{{Cite web |last=Zhou |first=Xiaoyan |last2=Zhou |first2=Yifang |last3=Yu |first3=Le |last4=Qi |first4=Luhe |last5=Oh |first5=Kyeong-Seok |last6=Hu |first6=Pei |last7=Lee |first7=Sang-Young |last8=Chen |first8=Chaoji |date=2024-04-18 |title=Gel polymer electrolytes for rechargeable batteries toward wide-temperature applications |url=https://pubs.rsc.org/en/content/articlelanding/2024/cs/d3cs00551h |url-status=live |access-date=2025-05-24 |page=5291–5337 |language=en |doi=10.1039/D3CS00551H |quote=Gel polymer electrolytes (GPEs) are composed of a polymer matrix that immobilizes liquid electrolyte components to form a semi-solid structure. GPEs combine the safety and mechanical advantages of solid electrolytes with the high ionic conductivity of liquid electrolytes.}}</ref>
== Components ==

A typical cell has four main components: a positive [[electrode]], a negative electrode, a separator, and an [[electrolyte]]. The separator itself may be a [[polymer]], such as a microporous film of [[polyethylene]] (PE) or [[polypropylene]] (PP); thus, even when the cell has a liquid electrolyte, it will still contain a "polymer" component. In addition to this, the positive electrode can be further divided into three parts: the lithium-transition-metal-oxide (such as LiCoO<sub>2</sub> or LiMn<sub>2</sub>O<sub>4</sub>), a conductive additive, and a polymer binder of [[Polyvinylidene fluoride|poly(vinylidene fluoride)]] (PVdF).<ref name="book_1"/><ref name="book_2"/> The negative electrode material may have the same three parts, only with [[carbon]] replacing the lithium-metal-oxide.<ref name="book_1">{{cite book |last=Yazami |first=Rachid |editor-last=Ozawa |editor-first=Kazunori |title=Lithium ion rechargeable batteries |publisher=Wiley-Vch Verlag GmbH & Co. KGaA |date=2009 |chapter=Chapter 5: Thermodynamics of Electrode Materials for Lithium-Ion Batteries |isbn=978-3-527-31983-1}}</ref><ref name="book_2">{{cite book |last=Nagai |first=Aisaku |editor-last1=Yoshio |editor-first1=Masaki |editor-last2=Brodd |editor-first2=Ralph J. |editor-last3=Kozawa |editor-first3=Akiya |title=Lithium-ion batteries |publisher=Springer |date=2009 |chapter=Chapter 6: Applications of Polyvinylidene Fluoride-Related Materials for Lithium-Ion Batteries |isbn=978-0-387-34444-7 |doi=10.1007/978-0-387-34445-4|bibcode=2009liba.book.....Y }}</ref> The main difference between lithium-ion polymer cells and lithium-ion cells is the physical phase of the electrolyte, such that LiPo cells use dry solid, gel-like electrolytes, whereas Li-ion cells use liquid electrolytes.

== 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>

== Voltage and state of charge ==
{{main|Lithium-ion battery#Charge and discharge}}

The voltage of a single LiPo cell depends on its chemistry and varies from about 4.2&nbsp;V (fully charged) to about 2.7–3.0&nbsp;V (fully discharged). The nominal voltage is 3.6 or 3.7 volts (about the middle value of the highest and lowest value) for cells based on lithium-metal-oxides (such as LiCoO<sub>2</sub>). This compares to 3.6–3.8&nbsp;V (charged) to 1.8–2.0&nbsp;V (discharged) for those based on lithium-iron-phosphate (LiFePO<sub>4</sub>).

The exact voltage ratings should be specified in product data sheets, with the understanding that the cells should be protected by an electronic circuit that won't allow them to overcharge or over-discharge under use.

LiPo [[battery pack]]s, with cells connected in series and parallel, have separate pin-outs for every cell. A specialized charger may monitor the charge per cell so that all cells are brought to the same state of charge (SOC).

== Applications ==
{{main|Lithium-ion battery#Uses}}
[[File:Custom Cells Itzehoe GmbH free form factor battery for Unmanned Underwater Vehicle (UUV AUV).png|thumb|Hexagonal lithium polymer battery for underwater vehicles]]
[[File:Lithium polymer battery (11.1 volts).jpg|thumb|Three-cell LiPo battery for [[Radio-controlled model|RC models]]]]

LiPo cells provide manufacturers with compelling advantages. They can easily produce batteries of almost any desired shape. For example, the space and weight requirements of [[mobile device]]s and [[notebook computers]] can be met. They also have a low self-discharge rate of about 5% per month.<ref>{{cite web|title=Lithium Polymer Battery Technology|url=http://www.manoonpong.com/Other/main_page=page_2.pdf|access-date=14 March 2016}}</ref>

LiPo batteries are now almost ubiquitous when used to power commercial and hobby drones ([[unmanned aerial vehicle]]s), [[radio-controlled aircraft]], [[radio-controlled car]]s, and large-scale model trains, where the advantages of lower weight and increased capacity and power delivery justify the price. Test reports warn of the risk of fire when the batteries are not used per the instructions.<ref name="Dunn">{{cite web |url=http://www.tested.com/tech/502351-rc-battery-guide-basics-lithium-polymer-batteries/ |title=Battery Guide: The Basics of Lithium-Polymer Batteries |last=Dunn |first=Terry |date=5 March 2015 |website=Tested |publisher=Whalerock Industries |access-date=15 March 2017 |quote=I’ve not yet heard of a LiPo that burst into flames during storage. All of the fire incidents that I’m aware of occurred during charge or discharge of the battery. Of those cases, the majority of problems happened during charge. Of those cases, the fault usually rested with either the charger or the person who was operating the charger... but not always. |archive-date=16 March 2017 |archive-url=https://web.archive.org/web/20170316024420/http://www.tested.com/tech/502351-rc-battery-guide-basics-lithium-polymer-batteries/ |url-status=dead }}</ref> The voltage for long-time storage of LiPo battery used in the R/C model should be 3.6~3.9&nbsp;V range per cell, otherwise it may cause damage to the battery.<ref>{{cite web|title=A LIPO BATTERY GUIDE TO UNDERSTAND LIPO BATTERY|url=https://www.genstattu.com/bw/|access-date=3 September 2021}}</ref>

LiPo packs also see widespread use in [[airsoft]], where their higher discharge currents and better energy density than traditional [[NiMH]] batteries have very noticeable performance gain (higher rate of fire).{{or|date=May 2025}}

LiPo batteries are pervasive in [[mobile device]]s, [[power bank]]s, [[subnotebook|very thin laptop computers]], [[portable media players]], wireless controllers for video game consoles, wireless PC peripherals, [[electronic cigarette]]s, and other applications where small form factors are sought. The high energy density outweighs cost considerations.

The battery used to start a vehicle's [[internal combustion engine]] is typically 12&nbsp;V or 24&nbsp;V, so a portable jump starter or battery booster uses three or six LiPo batteries in series (3S1P/6S1P) to start the vehicle in an emergency instead of the [[Jump start (vehicle)|other jump-start methods]]. The price of a lead-acid jump starter is less but they are bigger and heavier than comparable lithium batteries. So such products have mostly switched to LiPo batteries or sometimes lithium iron phosphate batteries.

[[Hyundai Motor Company]] uses LiPo batteries in some of its [[Battery electric vehicle|battery-electric]] and [[hybrid electric vehicle|hybrid vehicles]]<ref>{{cite news|last=Brown|first=Warren|title=2011 Hyundai Sonata Hybrid: Hi, tech. Bye, performance|url=https://www.washingtonpost.com/business/2011/08/18/gIQAWh0uPJ_story.html|newspaper=Washington Post|access-date=25 November 2011|date=3 November 2011}}</ref> and [[Kia Motors]] in its [[Kia Soul EV|battery-electric Kia Soul]].<ref>{{Cite web|url=http://www.kia.com/worldwide/about-kia/company/corporate-news-view.aspx?idx=718|title = Sustainability &#124; Kia Global Brand Site}}</ref> The [[Bolloré Bluecar]], which is used in car-sharing schemes in several cities, also uses this type of battery.

LiPo batteries are becoming increasingly commonplace in [[Uninterruptible power supply]] (UPS) systems. They offer numerous benefits over the traditional [[VRLA battery]], and with stability and safety improvements confidence in the technology is growing. Their power-to-size and weight ratio is seen as a major benefit in many industries requiring critical power backup, including data centers where space is often at a premium.<ref>{{Cite web|url=https://powercontrol.co.uk/blog/lithium-ion-or-lithium-iron-ups-2/|title=Lithium-ion vs Lithium Iron: Which is the most suitable for a UPS system?}}</ref> The longer cycle life, usable energy (Depth of discharge), and thermal runaway are also seen as a benefit of using Li-po batteries over VRLA batteries.

== Safety and robustness ==
{{main|Lithium-ion battery#Safety}}
[[File:Expanded lithium-ion polymer battery from an Apple iPhone 3GS.jpg|thumb|Apple [[iPhone 3GS]]'s Lithium-ion battery, which has expanded due to a short-circuit failure]]
[[File:NASA Lithium Ion Polymer Battery.jpg|thumb|An experimental lithium-ion polymer battery made by Lockheed Martin for NASA]]

All Li-ion cells expand at high levels of [[state of charge]] (SOC) or overcharge due to slight vaporisation of the electrolyte. This may result in [[delamination]] and, thus, bad contact with the internal layers of the cell, which in turn diminishes the reliability and overall cycle life.<ref name="ageing"/> This is very noticeable for LiPos, which can visibly inflate due to the lack of a hard case to contain their expansion. Lithium polymer batteries' safety characteristics differ from those of [[Lithium iron phosphate battery#Safety|lithium iron phosphate batteries]].

Unlike lithium-ion cylindrical and prismatic cells, with a rigid metal case, LiPo cells have a flexible, foil-type (polymer [[laminate]]) case, so they are relatively unconstrained. Moderate pressure on the stack of layers that compose the cell results in increased capacity retention, because the contact between the components is maximised and [[delamination]] and deformation is prevented, which is associated with increase of cell impedance and degradation.<ref name="ageing">{{cite journal |journal=Journal of Power Sources |volume=147 |issue=1–2 |date=9 September 2005 |pages=269–281 |title=Ageing mechanisms in lithium-ion batteries |last1=Vetter |first1=J. |last2=Novák |first2=P. |last3=Wagner |first3=M.R. |last4=Veit |first4=C. |doi=10.1016/j.jpowsour.2005.01.006|bibcode=2005JPS...147..269V }}</ref><ref name="pressure">{{cite journal |journal=Journal of Power Sources |volume=245 |date=1 January 2014 |pages=745–751 |title=Stress evolution and capacity fade in constrained lithium-ion pouch cells |last1=Cannarella |first1=John |last2=Arnold |first2=Craig B. |doi=10.1016/j.jpowsour.2013.06.165|bibcode=2014JPS...245..745C }}</ref>

== Future developments ==

A solid polymer electrolyte (SPE) is a solvent-free salt solution in a polymer medium. It may be, for example, a compound of lithium bis(fluorosulfonyl)imide (LiFSI) and high molecular weight [[Polyethylene glycol|poly(ethylene oxide)]] (PEO),<ref name="polymer 1">{{cite journal |journal=Electrochimica Acta |volume=133 |date=1 July 2014 |pages=529–538 |title=Lithium bis(fluorosulfonyl)imide/poly(ethylene oxide) polymer electrolyte |last1=Zhang |first1=Heng |last2=Liu |first2=Chengyong |last3=Zheng |first3=Liping |doi=10.1016/j.electacta.2014.04.099}}</ref> a high molecular weight [[poly(trimethylene carbonate)]] (PTMC),<ref name="polymer 2">{{cite journal |journal=Solid State Ionics |volume=262 |date=1 September 2014 |pages=738–742 |title=Polycarbonate-based solid polymer electrolytes for Li-ion batteries |last1=Sun |first1=Bing |last2=Mindemark |first2=Jonas |last3=Edström |first3=Kristina |author-link3=Kristina Edström |last4=Brandell |first4=Daniel |doi=10.1016/j.ssi.2013.08.014}}</ref> polypropylene oxide (PPO), poly[bis(methoxy-ethoxy-ethoxy)phosphazene] (MEEP), ''etc''. PEO exhibits the most promising performance as a solid solvent for lithium salts, mainly due to its flexible ethylene oxide segments and other oxygen atoms that comprise a strong donor character, readily solvating Li<sup>+</sup> cations. PEO is also commercially available at a very reasonable cost.<ref name=":0" /> The performance of these proposed electrolytes is usually measured in a [[half-cell]] configuration against an electrode of metallic [[lithium]], making the system a "[[lithium battery|lithium-metal]]" cell. Still, it has also been tested with a common lithium-ion cathode material such as [[Lithium iron phosphate battery|lithium-iron-phosphate]] (LiFePO<sub>4</sub>).

Cells with solid polymer electrolytes have not been fully commercialised<ref>{{cite web |last1=Blain |first1=Loz |title=Solid state battery breakthrough could double the density of lithium-ion cells |url=https://newatlas.com/science/deakin-solid-state-battery-polymer-electrolyte/ |website=New Atlas |date=27 November 2019 |publisher=Gizmag |access-date=6 December 2019}}</ref> and are still a topic of research.<ref>{{cite journal |last1=Wang |first1=Xiaoen |last2=Chen |first2=Fangfang |last3=Girard |first3=Gaetan M.A. |last4=Zhu |first4=Haijin |last5=MacFarlane |first5=Douglas R. |last6=Mecerreyes |first6=David |last7=Armand |first7=Michel |last8=Howlett |first8=Patrick C. |last9=Forsyth |first9=Maria |title=Poly(Ionic Liquid)s-in-Salt Electrolytes with Co-coordination-Assisted Lithium-Ion Transport for Safe Batteries |journal=Joule |date=November 2019 |volume=3 |issue=11 |pages=2687–2702 |doi=10.1016/j.joule.2019.07.008 |doi-access=free }}</ref> Prototype cells of this type could be considered to be between a traditional [[lithium-ion]] battery (with liquid electrolyte) and a completely plastic, [[solid-state lithium-ion battery]].<ref name="book_3"/> The simplest approach is to use a polymer matrix, such as [[polyvinylidene fluoride]] (PVdF) or [[polyacrylonitrile|poly(acrylonitrile)]] (PAN), gelled with conventional salts and solvents, such as [[lithium hexafluorophosphate|LiPF<sub>6</sub>]] in [[Ethylene carbonate|EC]]/[[Dimethyl carbonate|DMC]]/[[Diethyl carbonate|DEC]].

Other attempts to design a polymer electrolyte cell include the use of [[inorganic chemistry|inorganic]] [[ionic liquid]]s such as 1-butyl-3-methylimidazolium tetrafluoroborate ([BMIM]BF<sub>4</sub>) as a plasticizer in a microporous polymer matrix like poly(vinylidene fluoride-co-hexafluoropropylene)/poly(methyl methacrylate) (PVDF-HFP/PMMA).<ref name="polymer 3">{{cite journal |journal=Electrochimica Acta |volume=133 |date=1 July 2014 |pages=623–630 |title=Study of PVDF-HFP/PMMA blended micro-porous gel polymer electrolyte incorporating ionic liquid [BMIM]BF<sub>4</sub> for Lithium ion batteries |last1=Zhai |first1=Wei |last2=Zhu |first2=Hua-jun |last3=Wang |first3=Long |doi=10.1016/j.electacta.2014.04.076}}</ref>

== See also ==

* [[List of battery types]]
* [[Lithium–air battery]]
* [[Lithium iron phosphate battery]]
* [[Research in lithium-ion batteries]]

== References ==

{{refs}}

== External links ==
{{commonscat|Lithium-polymer batteries}}

* [http://www.mpoweruk.com/battery_manufacturing.htm Electropaedia on Lithium Battery Manufacturing]
* [http://www.mpoweruk.com/lithium_failures.htm Electropaedia on Lithium Battery Failures]

{{Galvanic cells}}

{{Use dmy dates|date=June 2020}}
[[Category:Lithium-ion batteries]]