Kodi LiFePO4 mu mabatire a lithiamu ndi chiyani?
Mau oyamba a Lithium Iron Phosphate Materials
Lithium iron phosphate (molecular formula LiFePO₄, lithiamu iron phosphate, LFP, yomwe imadziwikanso kuti lithiamu iron phosphate kapena ferrous lithium phosphate) ndi zinthu za cathode zomwe zimagwiritsidwa ntchito mu mabatire a lithiamu-ion. Makhalidwe ake ndikuti alibe zinthu zamtengo wapatali monga cobalt kapena nickel, mtengo wamtengo wapatali ndi wotsika; ndipo mpweya, lithiamu, ndi chitsulo n’zochuluka m’nthaka ya dziko lapansi, zomwe zingakwaniritse zofuna za msika zoposa matani miliyoni imodzi pachaka. Monga zinthu za cathode, lithiamu iron phosphate imakhala ndi mphamvu yogwira ntchito yocheperako (3.2 V), mphamvu yeniyeni yeniyeni (170 mA·h/g), mphamvu yotulutsa kwambiri, kutha kwachangu, komanso moyo wautali wozungulira, wokhala ndi kukhazikika kwapamwamba{5}}kutentha ndi -malo otentha kwambiri.
Lifiyamu iron phosphate crystal ndi ya mtundu umodzi wa olivine. Mu mineralogy, amatchedwa triphylite, kuchokera ku liwu lachi Greek lakuti "root" ndi "lylon". Mu ore, mtundu ukhoza kukhala wotuwa, wofiira{2}}bulauni, bulauni, kapena wakuda, pamene zinthu zenizeni zimakhala zakuda kapena zotuwa{3}}zakuda. Zina zachilengedwe zamchere zamchere zimakhala ndi lithiamu iron phosphate, koma kalasiyo ndi yotsika ndipo sichifika pamlingo wogwiritsa ntchito. Lifiyamu chitsulo mankwala ndi gulu gulu phosphate, ndi chilinganizo ake ambiri mankhwala ayenera LiMPO₄, kumene M akhoza kukhala zitsulo aliyense divalent, kuphatikizapo Fe, Co, Mn, Ti, etc. Chifukwa kampani yoyamba kugulitsa LiMPO₄ opangidwa lifiyamu chitsulo mankwala, anthu anazolowera kuchitira phosphate chitsulo mankwala monga cathode zinthu yekha gulu. Komabe, pophatikiza ndi kapangidwe ka olivine, lithiamu iron phosphate si yokhayo yomwe ingagwiritsidwe ntchito ngati cathode material mu lithiamu{8}}mabatire a ion. Malinga ndi chidziwitso chapano, palinso LiMnPO₄, LiMnFePO₄, LiVPO₄, LiCoPO₄, ndi zida zina zambiri.
Magwero a zipangizo za lithiamu chitsulo mankwala akhoza kubwera ku 1996, pamene Japan kampani yolumikizirana foni NTT poyamba anapeza kuti AMPO₄ (A ndi alkali zitsulo, M ndi Co kapena Fe) ndi kapangidwe olivine, osakaniza LiFeCoPO₄, angagwiritsidwe ntchito ngati lifiyamu -ion batire cathode chuma. Pambuyo pake, gulu lofufuza la Goodenough ku Massachusetts Institute of Technology ku United States, pophunzira za framework compounds, kuti lithiamu iron phosphate zili ndi katundu wosinthika wa lithiamu{3}}ion (Li⁺) intercalation ndi deintercalation. Pa April 23, 1997, University of Texas ku Austin ada mangala patent lotchedwa "Zida Cathode kwa rechargeable lithiamu sekondale mabatire" (WO1997010541), chosonyeza chiyambi cha patent monopoly pa lithiamu chitsulo phosphate zipangizo.
Kufalitsidwa munthawi yomweyo kwa olivine-structured phosphate (LiMPO₄) cathode materials by United States ndi Japan kudachititsa chidwi, kudayambitsa kafukufuku wambiri, ndipo kupititsa patsogolo ntchito zama mafakitale. Poyerekeza ndi zinthu zakale za lithiamu-ion secondary battery cathode materials-spinel-structured lithium manganese oxide (LiMn₂O₄) and layered{5}}structured lithium cobalt oxide (LiCoO₂){6}}LiMPO₄ ili ndi zopangira zowononga zachilengedwe komanso zotsika mtengo. Makamaka, chitetezo chawongoleredwa kwambiri, ndikudzutsa chidwi chachikulu kuchokera kwa ofufuza ndi mafakitale.
Malinga ndi zotsatira za kafukufuku m'zaka zaposachedwa, zinthu za lithiamu iron phosphate zili ndi chitsime{{0}chopangidwa ndi olivine, ndipo mayendedwe ake a lithiamu{1}}amasiyana ndi ma cathode akale. Zipangizo zamakono za cathode zimakhala ndi zigawo zozungulira kapena za spinel, zomwe zimalola kuti lithiamu ions zisunthike mofulumira pakati pa zigawo kapena muzitsulo zazikulu, motero zimapatsa zipangizozo ndi ntchito yabwino yotulutsa. Mosiyana, njira zoyatsira lithiamu-ion diffusion mu lithiamu iron phosphate ndi imodzi-dimensional, kutanthauza kuti mkati mwa krustalo muli "tunnel" yokha ya lithiamu{6}}ion diffusion, kotero kuti lifiyamu{7}}kusuntha kwa ion kumakhala kocheperako ndipo mtunda wofalikira ndi waufupi. Makamaka pansi pa-kuthamanga kwambiri, ma ion lifiyamu amkati sangathe kutuluka munthawi yake, zomwe zimapangitsa kuti ma electrochemical polarization ayambe.
Mabatire amatha kupangidwa pogwiritsa ntchito zida za lithiamu iron phosphate kuti zitsimikizire zomwe zili pamwambapa. Kuyesera kwawonetsa kuti mphamvu yogwiritsira ntchito zinthu zoyera za lithiamu iron phosphate ndizochepa kwambiri, ndipo batire imawola mwachangu pakuyendetsa njinga. Chithunzi 2.1 chikuwonetsa kayendesedwe ka selo la lifiyamu-lopangidwa ndi wolemba pogwiritsa ntchito lithiamu iron phosphate yopangidwa ndi hydrothermally (popanda zokutira kaboni). Zitha kuwoneka kuti patatha pafupifupi maulendo 15 otulutsa, mphamvu ya batri yawonongeka ndi 20%. Chifukwa chake, zinthu zowona za lithiamu iron phosphate sizoyenera kugwiritsa ntchito mabatire a lithiamu-ion.
Mu 2000, Hydro-Québec (H-Q), Canada wa dziko lonse zofunikira pagulu, anali woyamba filelo zovomerezeka pa ❖ kuyanika lifiyamu chitsulo mankwala ndi zipangizo conductive, kuphatikizapo ntchito mpweya ❖ kuyanika pa lithiamu chitsulo phosphate zipangizo. Izi zinapangitsa kuti lithiamu iron phosphate ikwanitse kukwanilitsa kuchuluka kwapadera ndikukulitsa moyo wake wozungulira mpaka kupitilira 2000. Ichi chinali chiyambi cha mafakitale ndondomeko ya lithiamu chitsulo mankwala monga zakuthupi cathode.
