Lub hauv paus ntsiab lus ntawm graphitization suav nrog kev kho cua sov kub siab (2300–3000 ° C), uas ua rau muaj kev hloov pauv ntawm cov amorphous, disordered carbon atoms mus rau hauv ib qho thermodynamically ruaj khov peb-dimensional ordered graphite crystal structure. Lub hauv paus ntawm cov txheej txheem no yog nyob rau hauv kev tsim kho dua tshiab ntawm lub hexagonal lattice los ntawm SP² hybridization ntawm carbon atoms, uas tuaj yeem faib ua peb theem:
Theem Kev Loj Hlob Microcrystalline (1000–1800 ° C):
Hauv qhov kub thiab txias no, cov khoom tsis huv hauv cov khoom siv carbon (xws li cov hlau uas tsis tshua muaj melting-point, sulfur, thiab phosphorus) pib ua pa thiab volatilize, thaum cov qauv planar ntawm cov txheej carbon maj mam nthuav dav. Qhov siab ntawm microcrystals nce ntxiv los ntawm qhov pib ~ 1 nanometer mus rau 10 nanometers, tso lub hauv paus rau kev txiav txim tom ntej.
Theem Kev Txiav Txim Peb-Seem (1800–2500°C):
Thaum qhov kub nce siab, qhov sib txawv ntawm cov txheej carbon txo qis, thiab qhov sib nrug ntawm cov txheej sib txawv maj mam nqaim mus rau 0.343–0.346 nanometers (mus txog qhov zoo tagnrho graphite ntawm 0.335 nanometers). Qib graphitization nce ntxiv ntawm 0 txog 0.9, thiab cov khoom siv pib ua kom pom cov yam ntxwv graphite sib txawv, xws li kev ua hluav taws xob thiab thermal conductivity zoo dua.
Theem Siv Crystal Perfection (2500–3000°C):
Thaum kub dua, cov microcrystals raug hloov pauv, thiab cov lattice defects (xws li qhov chaw khoob thiab dislocations) raug kho maj mam, nrog rau qib graphitization ze li ntawm 1.0 (crystal zoo tagnrho). Ntawm lub sijhawm no, cov khoom siv hluav taws xob resistivity tuaj yeem txo qis los ntawm 4-5 zaug, thermal conductivity txhim kho los ntawm kwv yees li 10 zaug, tus coefficient ntawm linear expansion poob qis los ntawm 50-80%, thiab kev ruaj khov tshuaj lom neeg tau txhim kho ntau heev.
Lub zog kub siab yog lub zog tseem ceeb rau kev ua graphitization, kov yeej qhov teeb meem zog rau kev hloov pauv carbon atom thiab ua rau muaj kev hloov pauv ntawm qhov tsis sib haum xeeb mus rau qhov kev teeb tsa. Tsis tas li ntawd, kev ntxiv cov catalysts (xws li boron, hlau, lossis ferrosilicon) tuaj yeem txo qhov kub ntawm graphitization thiab txhawb kev sib kis ntawm carbon atom thiab kev tsim lattice. Piv txwv li, thaum ferrosilicon muaj 25% silicon, qhov kub ntawm graphitization tuaj yeem txo qis ntawm 2500–3000 ° C txog 1500 ° C, thaum tsim cov hexagonal silicon carbide los pab tsim graphite.
Tus nqi ntawm daim ntawv thov ntawm graphitization yog pom tseeb hauv kev txhim kho ntawm cov khoom siv:
- Kev Ua Hluav Taws Xob: Tom qab graphitization, cov khoom siv hluav taws xob resistivity txo qis heev, ua rau nws yog tib yam khoom siv tsis yog hlau uas muaj kev ua hluav taws xob zoo heev.
- Kev Ua Tau Thermal: Kev ua tau thermal zoo dua li ntawm 10 npaug, ua rau nws tsim nyog rau kev siv thermal tswj.
- Kev Ruaj Ntseg Tshuaj: Kev tiv thaiv oxidation thiab kev tiv thaiv corrosion tau txhim kho, ua rau lub neej ua haujlwm ntawm cov khoom ntev dua.
- Cov Khoom Siv Kho Tshuab: Txawm hais tias lub zog yuav txo qis, cov qauv pore tuaj yeem txhim kho los ntawm kev impregnation, ua rau kom ceev thiab hnav tsis kam.
- Kev Txhim Kho Kev Huv Si: Cov khoom tsis huv yuav yaj thaum kub siab, txo cov tshauv ntawm cov khoom lag luam li ntawm 300 npaug thiab ua tau raws li qhov yuav tsum tau ua kom huv si.
Piv txwv li, hauv cov khoom siv roj teeb lithium-ion anode, graphitization yog ib kauj ruam tseem ceeb hauv kev npaj cov graphite anodes. Los ntawm kev kho graphitization, lub zog ceev, lub voj voog ruaj khov, thiab kev ua haujlwm ceev ntawm cov khoom siv anode tau txhim kho zoo heev, cuam tshuam ncaj qha rau kev ua haujlwm ntawm lub roj teeb. Qee cov graphite ntuj kuj raug kho kub siab kom txhim kho nws qib graphitization, yog li ua kom zoo dua qhov ceev ntawm lub zog thiab kev them-tawm efficiency.
Lub sijhawm tshaj tawm: Cuaj hlis-09-2025