LiFePO4 yog dab tsi hauv cov roj teeb lithium?
Taw qhia rau Lithium Iron Phosphate Materials
Lithium hlau phosphate (molecular mis LiFePO₄, lithium hlau phosphate, LFP, los yog lithium hlau phosphate los yog ferrous lithium phosphate) yog cov khoom siv cathode siv hauv lithium{0}} ion roj teeb. Nws cov yam ntxwv yog tias nws tsis muaj cov khoom tseem ceeb xws li cobalt lossis npib tsib xee, cov khoom siv raw khoom yog qis; thiab carbon, lithium, thiab hlau muaj ntau nyob rau hauv lub ntiaj teb lub crust, uas muaj peev xwm ua tau raws li kev lag luam xav tau ntau tshaj li ib lab tons hauv ib xyoos. Raws li cov khoom siv cathode, lithium hlau phosphate muaj qhov nruab nrab ua haujlwm voltage (3.2 V), muaj peev xwm tshwj xeeb (170 mA·h / g), lub zog tawm siab, muaj peev xwm them sai sai, thiab lub neej voj voog ntev, nrog kev ruaj ntseg zoo nyob rau hauv siab - kub thiab siab - cua sov ib puag ncig.
Lub lithium hlau phosphate crystal belongs rau ib hom olivine qauv. Hauv mineralogy, nws yog lub npe hu ua triphylite, muab los ntawm Greek lo lus keeb kwm tri thiab lylon. Hauv ores, xim tuaj yeem yog grey, liab doog -xim av grey, xim av, lossis dub, thaum cov khoom siv tiag tiag yog xim dub lossis grey-dub. Qee cov khoom siv ntxhia hauv ntuj muaj lithium hlau phosphate, tab sis qib qis thiab tsis ncav cuag qib ntawm kev siv tswv yim. Lithium hlau phosphate belongs rau pawg phosphate composite, thiab nws cov qauv tshuaj yuav tsum yog LiMPO₄, qhov twg M tuaj yeem yog cov hlau sib txawv, suav nrog Fe, Co, Mn, Ti, thiab lwm yam. cov khoom siv cathode. Txawm li cas los xij, rau cov khoom sib txuas nrog cov qauv olivine, lithium hlau phosphate tsis yog tib qho uas tuaj yeem siv los ua cov khoom siv cathode hauv lithium - ion roj teeb. Raws li kev paub tam sim no, tseem muaj LiMnPO₄, LiMnFePO₄, LiVPO₄, LiCoPO₄, thiab ntau lwm yam ntaub ntawv.
Lub hauv paus chiv keeb ntawm lithium hlau phosphate cov ntaub ntawv tuaj yeem taug qab mus rau xyoo 1996, thaum Nyiv lub tuam txhab kev sib txuas lus NTT thawj zaug pom tias AMPO₄ (A yog cov hlau alkali, M yog Co lossis Fe) nrog cov qauv olivine, hauv kev sib xyaw ntawm LiFeCoPO₄, tuaj yeem siv los ua cov khoom siv lithium{1}. Tom qab ntawd, nws tau tshawb pom los ntawm pawg tshawb fawb Goodenough ntawm Massachusetts Institute of Technology hauv Tebchaws Meskas, thaum kawm txog cov txheej txheem sib txuas, cov khoom siv lithium hlau phosphate muaj cov khoom rov qab ntawm lithium -} ion (Li⁺) intercalation thiab deintercalation. Thaum Lub Plaub Hlis 23, 1997, University of Texas ntawm Austin tau thov daim ntawv pov thawj patent hu ua "Cathode cov ntaub ntawv rau cov roj teeb lithium roj teeb rov qab" (WO1997010541), kos npe rau qhov pib ntawm patent monopoly ntawm lithium hlau phosphate cov ntaub ntawv.
Kev tshaj tawm ib txhij ntawm olivine- qauv phosphate (LiMPO₄) cov ntaub ntawv cathode los ntawm Tebchaws Meskas thiab Nyij Pooj tau txais kev saib xyuas zoo, ua rau muaj kev tshawb fawb dav dav, thiab ua kom cov txheej txheem kev lag luam sai sai. Piv nrog cov lithium lithium-Ion theem nrab roj teeb cathode cov ntaub ntawv-spinel-structured lithium manganese oxide (LiMn₂O₄) thiab txheej txheej-structured lithium cobalt oxide (LiCoO₂)-LiMPO₄ muaj ntau yam raw khoom uas tsis muaj raw khoom. Tshwj xeeb, kev nyab xeeb tau raug txhim kho zoo heev, ua rau muaj kev txaus siab zoo los ntawm cov kws tshawb fawb thiab kev lag luam.
Raws li kev tshawb fawb tau tshwm sim nyob rau hauv xyoo tas los no, lithium hlau phosphate cov ntaub ntawv muaj ib tug zoo -crystallized olivine qauv, thiab nws lithium{1}} ion diffusion channel txawv ntawm cov tsoos cathode cov ntaub ntawv. Cov khoom siv cathode ib txwm muaj txheej txheej lossis cov qauv spinel, tso cai rau lithium ions txav nrawm ntawm cov khaubncaws sab nraud povtseg lossis hauv cov channel loj, yog li muab cov ntaub ntawv pov thawj zoo. Hauv qhov sib piv, cov lithium-ion diffusion channels hauv lithium hlau phosphate cov ntaub ntawv yog ib qho -dimensional, txhais tau hais tias nyob rau hauv cov siv lead ua tsuas muaj "tunnel" rau lithium- ion diffusion, yog li cov lithium - ion migration rate kuj qeeb thiab qhov diffusion nrug yog luv. Tshwj xeeb tshaj yog nyob rau hauv siab - tus nqi paug tawm, cov lithium ions sab hauv tuaj yeem tsis tuaj yeem tawm hauv lub sijhawm, ua rau muaj qhov tseem ceeb ntawm electrochemical polarization.
Cov roj teeb tuaj yeem tsim tau siv cov khoom siv ntshiab lithium hlau phosphate los xyuas cov lus xaus saum toj no. Kev sim tau pom tias lub peev xwm siv cov khoom siv ntshiab lithium hlau phosphate tsawg heev, thiab cov roj teeb muaj peev xwm tawg sai thaum caij tsheb kauj vab. Daim duab 2.1 qhia tau hais tias kev caij tsheb kauj vab ntawm lithium - ion npib cell ua los ntawm tus sau siv hydrothermally synthesized ntshiab lithium hlau phosphate (tsis muaj carbon txheej). Nws tuaj yeem pom tau tias tom qab kwv yees li 15 lub sijhawm them-tso tawm, lub roj teeb muaj peev xwm tau lwj los ntawm ntau dua 20%. Yog li ntawd, cov khoom siv lithium hlau phosphate ntshiab tsis haum rau lithium -Ion roj teeb tshuab.
Xyoo 2000, Hydro-Québec (H-Q), Canada lub teb chaws siv hluav taws xob pej xeem, yog thawj tus ua ntawv patents ntawm txheej lithium hlau phosphate nrog cov khoom siv hluav taws xob, suav nrog kev siv cov pa roj carbon txheej ntawm cov ntaub ntawv lithium hlau phosphate. Qhov no tau ua rau lithium hlau phosphate kom ua tiav lub peev xwm tshwj xeeb thiab txuas ntxiv nws lub neej voj voog mus rau ntau tshaj 2000 lub voj voog. Qhov no tau cim qhov pib ntawm cov txheej txheem kev lag luam ntawm lithium hlau phosphate ua cov khoom siv cathode.
