Metallurgy hauv Lithium Ion roj teeb tsim khoom
Cov roj teeb lithium-ion tau dhau los ua lub hauv paus ntawm cov thev naus laus zis niaj hnub, los ntawm cov xov tooj ntse thiab cov laptops mus rau cov tsheb fais fab thiab cov chaw khaws cia hluav taws xob loj. Tom qab kev ua haujlwm zoo dua ntawm cov roj teeb - sib dua, muaj zog dua, thiab siv tau ntev dua - yog lub luag haujlwm tseem ceeb ntawm metallurgy. Metallurgy tsis yog hais txog kev smelting hlau xwb, tab sis suav nrog tag nrho cov txheej txheem ntawm kev rho tawm, kev ntxuav, kev tsim kho cov khoom siv, kev tswj hwm qhov tsis zoo, thiab kev siv rov qab. Hauv cov ntsiab lus ntawm cov roj teeb lithium-ion, metallurgy ua lub luag haujlwm hauv kev xaiv thiab ua cov khoom siv raw, kev tsim cov khoom siv cathode thiab anode, kev tsim cov khoom, thiab kev tswj hwm lub roj teeb thaum kawg ntawm lub neej.
1. Lub luag haujlwm ntawm metallurgy hauv cov saw hlau muab roj teeb
Cov roj teeb lithium-ion pib nrog kev khawb cov khoom siv hauv qab no: lithium (Li), nickel (Ni), cobalt (Co), manganese (Mn), hlau (Fe), txhuas (Al), tooj liab (Cu), thiab graphite (C). Metallurgy ua lub luag haujlwm tseem ceeb hauv kev hloov cov hlau mus rau hauv cov tshuaj lom neeg thiab cov khoom siv hlau uas muaj cov khoom ntshiab siab. Piv txwv li, tooj liab thiab txhuas yog qhov xav tau ua cov khoom sau tam sim no, thaum nickel, cobalt, manganese, thiab hlau yog cov ntsiab lus tseem ceeb ntawm cov khoom siv cathode. Lithium nws tus kheej yuav tsum tau ua tiav rau hauv cov tshuaj sib xyaw tsim nyog (piv txwv li, Li2CO3 lossis LiOH) rau kev tsim cathode.
Hauv lub ntiaj teb roj teeb, qhov yuav tsum tau ua kom huv si yog siab heev. Cov khoom tsis huv xws li hlau dawb, chloride, lossis qee yam khoom me me tuaj yeem cuam tshuam kev ruaj khov ntawm electrochemical, ua rau muaj kev puas tsuaj, thiab txawm tias ua rau muaj kev pheej hmoo ntawm kev ua tsis tiav ntawm thermal. Yog li ntawd, metallurgy ua lub luag haujlwm hauv kev ua kom huv si, kev tswj hwm kev ua qias tuaj, thiab kev kho cov ntaub ntawv lub cev - los ntawm cov hmoov zoo mus rau cov ntawv ci hlau.
2. Kev rho tawm thiab ua kom cov roj teeb lithium: los ntawm qhov chaw mus rau cov khoom siv roj teeb
Cov chaw tseem ceeb ntawm lithium yog brine (cov dej ntsev uas muaj ntau yam minerals) thiab cov pob zeb tawv xws li spodumene. Hauv brine, lithium raug concentrated los ntawm kev evaporation thiab cov tshuaj lom neeg reactions los tsim lithium carbonate. Hauv spodumene, cov ore feem ntau yog roasted kom hloov cov crystal theem kom ua rau lithium yooj yim dua rho tawm, ua raws li leaching thiab precipitation.
Cov kauj ruam no yog piv txwv ntawm cov ntawv thov metallurgy rho tawm, suav nrog pyrometallurgy (uas muaj qhov kub siab) thiab hydrometallurgy (uas muaj cov tshuaj). Kev xaiv txoj hauv kev ua haujlwm nyob ntawm qhov chaw, tus nqi zog, kev muaj reagent, thiab kev cuam tshuam rau ib puag ncig. Cov roj teeb niaj hnub no - tshwj xeeb tshaj yog cov uas muaj cathodes nplua nuj nickel - feem ntau xav tau LiOH zoo, ua rau cov txheej txheem refining nruj dua.
3. Cov ntaub ntawv Cathode: kev tsim kho hlau thiab cov qauv siv lead ua
Txawm hais tias lub anode feem ntau yog graphite-based, lub cathode yog lub zog "lub plawv" ntawm lub roj teeb, vam khom ntau rau cov hlau hloov pauv. Cov ntaub ntawv cathode feem ntau suav nrog:
– LFP (LiFePO4): siv hlau thiab phosphate, uas paub tias ruaj khov thiab muaj kev nyab xeeb.
- NMC (LiNixMnyCozO2) thiab NCA (LiNiCoAlO2): nickel nplua nuj rau lub zog ceev ceev.
– LMO (LiMn2O4): ua los ntawm manganese, tus nqi qis dua tab sis muaj kev cov nyom ntawm kev caij tsheb kauj vab thiab kev ruaj khov.
Cov khoom siv metallurgy ua lub luag haujlwm hauv kev tswj cov khoom sib xyaw, qhov loj me ntawm cov khoom me me, morphology, thiab theem siv lead ua. Cathodes feem ntau yog ua los ntawm kev tsim cov khoom siv ua ntej (piv txwv li, Ni-Mn-Co hydroxides lossis carbonates) uas tom qab ntawd raug calcined nrog lub lithium qhov chaw ntawm qhov kub siab. Qhov kub, huab cua (oxygen / inert), lub sijhawm tuav, thiab qhov txias txias txiav txim siab qhov tsim ntawm cov txheej txheem tsim nyog, spinel, lossis olivine qauv.
Qhov no yog qhov uas cov tswv yim metallurgical xws li cov khoom khov kho diffusion, theem hloov pauv, thiab kev tswj cov noob qoob loo ua qhov tseem ceeb. Piv txwv li, NMC cathodes xav tau cov qauv txheej txheem zoo kom cov lithium ions txav mus rau hauv thiab tawm tau zoo. Qhov tsis zoo xws li cation sib xyaw ntawm Ni thiab Li tuaj yeem txo qhov muaj peev xwm thiab ua kom nrawm dua degradation.
4. Cov teeb meem anode, cov khoom siv tam sim no, thiab cov teeb meem xeb
Cov anode feem ntau yog graphite, tab sis muaj kev nce qib mus rau silicon (Si)-based anodes lossis graphite-silicon alloys rau cov peev xwm siab dua. Txawm hais tias silicon tsis yog qhov tseem ceeb ntawm kev ua metallurgy ib txwm muaj, cov ntsiab cai ntawm cov khoom siv metallurgy tseem ceeb: kev tswj qhov loj me ntawm cov khoom me me, kev tawg, thiab kev ruaj khov ntawm qhov interface vim muaj kev nthuav dav ntau thaum lub sijhawm them.
Cov khoom siv hlau uas pom tseeb yog lub tshuab sau tam sim no:
- Tooj liab (Cu) ntawv ci rau lub anode.
- Ntawv ci txhuas (Al) rau cathode.
Qhov zoo ntawm cov ntawv ci yog txiav txim siab los ntawm cov txheej txheem metallurgical xws li dov, annealing, tswj tuab, qhov roughness ntawm qhov chaw, thiab purity. Cov chaw ntxhib lossis muaj kuab paug ntau dhau tuaj yeem cuam tshuam rau qhov lo rau ntawm cov electrode slurry. Ntxiv mus, corrosion kuj yog ib qho teeb meem tseem ceeb. Electrodes ua haujlwm hauv cov organic electrolytes nrog cov ntsev xws li LiPF6, uas tuaj yeem tsim cov tshuaj reactive (piv txwv li, HF nyob rau hauv qee qhov xwm txheej), ua rau kev tiv thaiv corrosion thiab kev ruaj khov ntawm txheej saum npoo yog qhov tseem ceeb rau kev nyab xeeb.
5. Hmoov metallurgy thiab electrode manufacturing
Kev tsim cov electrode suav nrog kev sib tov cov khoom siv nquag (cathode / anode), tus neeg coj (carbon black), thiab cov binder (piv txwv li, PVDF lossis cov dej-based binder) rau hauv cov slurry, tom qab ntawd txheej nws rau ntawm cov hlau ntawv ci. Tom qab ziab, lub electrode raug compacted los ntawm calendaring kom ua tiav qhov ceev tshwj xeeb.
Los ntawm qhov pom ntawm hmoov metallurgy, cov txheej txheem no zoo ib yam li kev tsim cov khoom siv raws li cov khoom me me: kev faib tawm ntawm cov khoom me me, porosity, thiab conductive network txiav txim siab qhov ua tau zoo. Porosity yuav tsum txaus kom tso cai rau electrolyte nkag mus, tab sis tsis ntau dhau kom tswj tau qhov ceev ntawm lub zog siab. Kev tswj hwm ntawm electrode microstructure - feem ntau tshuaj xyuas siv SEM, XRD, thiab lwm yam txheej txheem piav qhia - yog qhov tseem ceeb rau kev ua kom muaj kev tsim khoom tas mus li.
6. Kev sib cuam tshuam thiab kev ua tsis tiav ntawm qhov interface: dendrites, tawg, thiab kev puas tsuaj
Txawm hais tias cov roj teeb lithium-ion tsis yog "hlau" ntshiab, ntau yam ntawm lawv cov teeb meem tsis ua haujlwm yog cuam tshuam nrog tus cwj pwm ntawm cov ntaub ntawv thiab cov interfaces, uas poob rau hauv lub ntiaj teb ntawm metallurgy lub cev. Piv txwv li:
- Kev tsim ntawm SEI (Khoom Siv Electrolyte Interphase) txheej ntawm lub anode: txheej no yog qhov tseem ceeb los tiv thaiv lub anode, tab sis yog tias nws tsis ruaj khov nws tuaj yeem txuas ntxiv loj hlob thiab noj lithium.
- Kev tawg ntawm cov khoom cathode, tshwj xeeb tshaj yog nyob rau hauv cov ntaub ntawv nplua nuj nickel, vim muaj kev ntxhov siab sab hauv thaum lub sijhawm caij tsheb kauj vab.
- Kev plating lithium rau ntawm anode thaum lub sijhawm them ceev lossis qhov kub qis, uas tuaj yeem ua rau muaj dendrite tsim thiab muaj kev pheej hmoo ntawm luv luv circuits.
Kev siv hlau pab txhawb kev tsim kho saum npoo av (txheej txheej), kev sib xyaw nrog cov ntsiab lus tshwj xeeb los ua kom lub qauv ruaj khov, thiab tswj kev ntxhov siab seem. Txoj hauv kev "tsim qauv uas paub txog microstructure" yog ib qho uas siv ntau heev: kev ua kom cov khoom siv zoo tshaj plaws ntawm qib micro kom ua tau zoo tshaj plaws ntawm qib macro.
7. Kev siv roj teeb dua tshiab: kev khawb av hauv nroog thiab kev lag luam ncig
Kev siv roj teeb lithium-ion rov ua dua tshiab yog ib qho kev lag luam uas muaj ntau yam khoom siv hlau. Thaum cov roj teeb siv tau tas, cov Ni, Co, Cu, thiab txawm tias Li yuav dhau los ua ib qho khoom muaj nqis. Cov txheej txheem rov ua dua tshiab feem ntau muaj xws li:
– Kev siv hluav taws xob los ua hluav taws xob: Cov roj teeb raug yaj kom tsim cov hlau sib xyaw (feem ntau yog Ni-Co-Cu) thiab cov slag. Cov txheej txheem no muaj zog thiab yoog tau, tab sis nws siv zog ntau thiab lithium feem ntau nkag mus rau hauv cov slag, xav tau cov kauj ruam ntxiv.
– Hydrometallurgy: siv kev leaching los yaj cov hlau, uas tom qab ntawd raug cais los ntawm kev nag lossis daus, kev rho tawm cov kuab tshuaj, lossis kev siv hluav taws xob. Muaj peev xwm tsim tau cov khoom huv siab, tab sis yuav tsum tau muaj kev tswj hwm cov tshuaj thiab cov khib nyiab kom zoo.
– Kev siv rov qab ncaj qha: sim tswj cov qauv cathode kom nws tuaj yeem rov tsim dua yam tsis tau "rhuav tshem" tag nrho cov ntsiab lus mus ua ions. Qhov no muab kev ua haujlwm zoo tab sis nws nyuaj vim muaj kev hloov pauv ntawm kev tsim roj teeb thiab kev puas tsuaj ntawm cov khoom siv.
Los ntawm qhov kev xav ntawm cov hlau, cov teeb meem tseem ceeb yog kev sib cais xaiv, kev tswj hwm qhov tsis huv, thiab kev xyuas kom meej tias cov khoom siv rov ua dua tshiab ua tau raws li cov lus qhia nruj ntawm cov khoom siv roj teeb tshiab.
8. Tej teeb meem thiab tej kev taw qhia yav tom ntej
Mus tom ntej, metallurgy hauv lithium-ion roj teeb yuav dhau los ua qhov tseem ceeb thaum qhov kev thov nce ntxiv thiab cov qauv kev ruaj khov ua kom nruj dua. Cov lus qhia tseem ceeb suav nrog kev txo cov cobalt rau kev ncaj ncees thiab tus nqi, kev siv nickel ntau ntxiv, uas xav tau kev tswj hwm microstructural kom meej dua, kev tsim cov cathodes LFP thiab LMFP rau tus nqi qis dua thiab kev nyab xeeb, thiab kev koom ua ke ntawm kev siv rov qab ua cov khoom siv raw tseem ceeb. Ntxiv mus, cov txheej txheem tsim kho tshiab - xws li kev ua kom zoo dua qub, kev siv cov tshuaj reagents rov ua dua tshiab, thiab txo cov pa roj carbon - yuav yog qhov tseem ceeb rau kev sib tw ntawm kev lag luam.
Xaus
Kev kawm txog hlau yog lub hauv paus zais cia tom qab kev nce qib ntawm cov roj teeb lithium-ion. Txij li kev rho tawm thiab kev ntxuav cov lithium thiab cov hlau hloov pauv, los ntawm kev tsim cov qauv siv lead ua cathode, kev tsim cov ntawv ci tam sim no, thiab kev tswj hwm cov interfaces uas txiav txim siab lub neej ntev, mus rau kev rov ua dua tshiab thiab kev lag luam ncig, txhua yam yuav tsum muaj kev nkag siab tob txog kev kawm txog hlau. Nrog rau kev nce qib ntawm cov tsheb fais fab thiab kev hloov pauv hluav taws xob thoob ntiaj teb, lub luag haujlwm ntawm kev kawm txog hlau yuav dhau los ua qhov tseem ceeb: xyuas kom muaj cov khoom siv raw, cov txheej txheem tsim khoom zoo, kev ua haujlwm zoo tshaj plaws ntawm roj teeb, thiab kev tswj hwm kev cuam tshuam ib puag ncig. Yog tias roj teeb yog lub cim ntawm yav tom ntej ntawm lub zog, ces kev kawm txog hlau yog ib qho ntawm cov cav tseem ceeb ua rau yav tom ntej ntawd ua tau.
