Kev ruaj ntseg thiab dispersibility ntawm roj teeb slurry muaj ib qho tseem ceeb cuam tshuam rau cov khoom ntawm electrodes thiab tiav cov khoom roj teeb. Yog li yuav ua li cas ua tus yam ntxwv ntawm stability thiab dispersibility ntawm roj teeb slurry?
Tus cwj pwm txoj kev ntawm roj teeb slurry stability
1. Txheej txheem txheej txheem
Txoj kev xeem cov ntsiab lus yog ib qho uas tsis muaj nqi thiab yooj yim rau kev xeem. Nws lub hauv paus ntsiab lus yog muab cov slurry tso rau hauv ib lub thawv thiab coj cov qauv ntawm tib qhov chaw nyob rau ib ntus mus kuaj thiab tshuaj xyuas cov ntsiab lus. Los ntawm kev txiav txim qhov sib txawv ntawm cov ntsiab lus, qhov ruaj khov ntawm lithium roj teeb slurry tuaj yeem txiav txim siab seb puas muaj sedimentation, stratification thiab lwm yam tshwm sim.
2. Txoj kev viscosity
Txoj kev ntsuas viscosity kuj tseem tuaj yeem cuam tshuam qhov kev ruaj ntseg ntawm slurry. Nws lub hauv paus ntsiab lus yog muab cov slurry tso rau hauv ib lub thawv thiab sim cov viscosity ntawm ib ntus. Kev ruaj ntseg ntawm slurry tuaj yeem txiav txim siab los ntawm kev hloov hauv viscosity.
3. Stability Analyzer
Kev siv cov ntsuas kev ruaj ntseg tuaj yeem hais nrog cov ntaub ntawv. Piv txwv li, Sung et al. siv lub ntsuas kev ruaj ntseg los saib xyuas lub teeb xa hluav taws xob hloov pauv ntawm pH slurries sib txawv siv PAA ua cov ntawv khi hauv 12 teev. Thawj lub teeb xa hluav taws xob thiab 12- teev hloov pauv qhov tseem ceeb ntawm qhov nruab nrab slurry tsawg dua. Vim tias cov khoom siv roj carbon dub muaj lub teeb pom kev zoo, lub teeb xa hluav taws xob qis qhia tau tias muaj kev cuam tshuam zoo dua ntawm cov pa roj carbon dub, thiab cov micro-agglomerates me me muaj cov cheeb tsam loj dua, yog li txhim kho lub teeb pom kev zoo. Nyob rau tib lub sijhawm, qhov kev hloov me me ntawm lub teeb xa hluav taws xob ntawm cov slurry hauv 12 teev qhia tias cov slurry muaj kev ruaj ntseg zoo thaum lub sijhawm txheej txheem zoo li qub, raws li qhia hauv daim duab hauv qab no.
4. Tus cwj pwm ntawm Zeta muaj peev xwm
Zeta muaj peev xwm hais txog lub peev xwm ntawm Shear Plane, tseem hu ua electrokinetic peev xwm lossis electromotive quab yuam, thiab yog qhov taw qhia tseem ceeb rau kev ua kom muaj kev ruaj ntseg ntawm colloidal dispersions. Qhov me me ntawm cov molecules los yog dispersed hais, qhov siab dua tus nqi ntawm Zeta muaj peev xwm (zoo lossis tsis zoo), thiab qhov system ruaj khov dua, uas yog, qhov tawg lossis tawg tuaj yeem tiv thaiv kev sib sau. Hloov pauv, qhov qis dua Zeta muaj peev xwm (qhov zoo lossis qhov tsis zoo), qhov ntau nws nyiam coagulate lossis sib sau ua ke, uas yog, qhov kev nyiam tshaj qhov kev tawm tsam, qhov tawg tau raug rhuav tshem thiab coagulation lossis kev sib sau tshwm sim.
Characterization txoj kev ntawm roj teeb slurry dispersion
1. Kev zoo
Fineness yog ib qho tseem ceeb ntawm kev ua tau zoo ntawm cov roj teeb slurry, uas tuaj yeem cuam tshuam cov ntaub ntawv xws li slurry particle loj thiab dispersion. Tus nqi zoo tuaj yeem siv los nkag siab seb cov khoom hauv slurry puas tau tawg thiab seb cov agglomerates puas yog deagglomerated.
2. Membrane impedance
Lithium roj teeb slurry yog ib qho khoom siv-kua sib xyaw ua ke tsim los ntawm cov khoom siv hluav taws xob dispersing thiab cov khoom siv hluav taws xob hauv cov kua nplaum. Raws li lub hauv paus ntsiab lus ntawm plaub-kev sojntsuam membrane impedance kuaj, slurry membrane impedance raug kuaj. Lub xeev kev faib khoom ntawm tus neeg sawv cev conductive hauv slurry tuaj yeem txheeb xyuas ntau los ntawm kev tiv thaiv los txiav txim qhov cuam tshuam ntawm cov slurry. Cov txheej txheem kev sim tshwj xeeb yog: siv cov ntawv thov zaj duab xis kom sib npaug ntawm cov slurry ntawm cov zaj duab xis insulating, tom qab ntawd kub thiab ziab nws, ntsuas lub thickness ntawm txheej tom qab ziab, txiav cov qauv, thiab qhov loj me raws li qhov yuav tsum tau ua. Thaum kawg, siv plaub qhov kev sojntsuam los ntsuas cov electrode membrane impedance thiab xam cov resistivity raws li thickness.
3. Scanning electron microscopy/Energy spectrum tsom xam/cryo-electron microscopy
Scanning electron microscopy (SEM) tuaj yeem siv ncaj qha rau kev soj ntsuam morphology ntawm roj teeb slurry, thiab koom tes nrog lub zog spectrum tsom xam (EDS) txhawm rau txheeb xyuas qhov tawg ntawm txhua yam. Txawm li cas los xij, thaum npaj cov qauv, kev ziab ntawm slurry thaum lub sijhawm txheej txheem no yuav ua rau rov ua dua ntawm nws cov khoom. Cryo-electron microscopy (Cryo-SEM) tuaj yeem tswj tau qhov kev faib tawm thawj zaug ntawm cov khoom slurry, yog li nws tau pib siv tsis ntev los no hauv kev tshuaj xyuas cov khoom slurry.
4. Electrode CT duab
Electrode CT duab tuaj yeem saib ncaj qha rau lub xeev dispersion ntawm cov khoom hauv electrode. Raws li pom nyob rau hauv daim duab nram qab no, muaj ntau qhov loj me me agglomerated nyob rau hauv lub electrode nyob rau hauv daim duab a, cov agglomerated hais nyob rau hauv lub electrode nyob rau hauv daim duab b yog ho txo, thiab yuav luag tsis muaj agglomerated loj hais nyob rau hauv lub electrode nyob rau hauv daim duab c.
5. Laser diffraction ntsuas tshuab
Laser diffraction ntsuas tshuab siv Fresnel scattering theory thiab Fraunhofer txoj kev xav kom tau txais qhov loj me thiab kev faib tawm. Lub laser particle loj analyzer raws li cov thev naus laus zis no muaj qhov ntsuas qhov tseeb, qhov rov ua tau zoo, thiab lub sijhawm ntsuas luv luv. Nws tau siv dav hauv cov chaw tsim khoom roj teeb los kuaj qhov me me ntawm slurry hauv cov roj teeb.
6. Electrochemical impedance spectroscopy tsom xam txoj kev
Piv txwv li, Wang et al. siv cov txheej txheem electrochemical impedance spectroscopy tsom xam (EIS) ncaj qha los soj ntsuam cov impedance spectrum ntawm cov kua slurry thiab tau txais cov yam ntxwv electrochemical ntawm slurry ntawm txawv particle concentrations. Thiab los ntawm cov txiaj ntsig ntawm impedance spectrum haum, ib qho kev ntsuam xyuas rau cov qauv kev faib tawm sab hauv ntawm cov hluav taws xob slurry raws li qhov ntsuas qhov sib npaug ntawm cov qauv hluav taws xob tau tsim, uas muab lub tswv yim tshiab rau kev ntsuas hauv online thiab kev ntsuam xyuas online ntawm cov qauv tsis sib xws. ntawm lithium-ion roj teeb slurry. Lub hauv paus ntsiab lus ntawm kev xeem EIS muaj nyob rau hauv daim duab.
Cov txheej txheem rau characterizing ob slurry stability thiab dispersibility
1. Rheometer
(1) Viscoelasticity xeem
The viscoelastic characteristics of the slurry are characterized by the relative valuesof the storage modulus (G′) and the loss modulus (G″). The storage modulus G′, also known as the elastic modulus, represents the capacity stored when the slurry undergoes reversible elastic deformation and is a measure of the elastic deformation of the slurry. The loss modulus G″, also known as the viscous modulus, represents the energy consumed when the slurry undergoes irreversible deformation and is a measure of the viscous deformation of the slurry. In the frequency scan, based on the relative size of G′and G″and evaluating the sensitivity of G′to the angular frequency, it is possible to reflect whether the slurry is in a fluid state or a solid-like state. In the low-frequency range, G′>G ″ thiab qhov sib txawv loj dua, qhov zoo dua qhov ruaj khov ntawm slurry. Raws li pom hauv daim duab hauv qab no, kev ruaj ntseg ntawm ntuj graphite slurry zoo dua li cov hluavtaws graphite slurry.
(2) Hloov viscosity nrog tus nqi shear
Lub viscosity ntawm slurry feem ntau hloov nrog tus nqi shear. Thaum shear thinning cwj pwm tshwm sim, muaj cov mos agglomerates hauv slurry uas yooj yim puas los ntawm shear stress. Ntawm qhov tsis sib xws, lub xub ntiag ntawm shear thickening feem ntau qhia tau hais tias muaj cov tawv aggregated nyob rau hauv slurry. Feem ntau hais lus, slurries nrog ceev shear thinning tus nqi yuav muaj zoo dispersibility, tsis quav ntsej txog kev puas tsuaj ntawm cov ntaub ntawv los ntawm shear quab yuam. Raws li pom nyob rau hauv daim duab hauv qab no, cov slurry uas sawv cev los ntawm lub voj voog hollow muaj dispersibility zoo dua li lwm cov slurries.
(3) Kev ntsuam xyuas kev nyuaj siab
Cov txiaj ntsig kev ntxhov siab nyob rau hauv rheology yog txhais raws li kev siv kev ntxhov siab ntawm cov yas deformation irreversible yog thawj zaug pom ntawm cov qauv. Raws li txoj cai, qhov kev ntxhov siab tawm los yog qhov kev ntxhov siab tsawg kawg nkaus yuav tsum tau pib ntws. Kev txheeb xyuas cov txiaj ntsig yog qhov tseem ceeb rau tag nrho cov txheej txheem ua kua dej. Nws pab kom nkag siab zoo dua cov khoom lag luam, xws li txee lub neej thiab kev ruaj ntseg tiv thaiv sedimentation lossis theem sib cais. Muaj ntau txoj hauv kev rheological uas tuaj yeem siv los txiav txim siab qhov kev ntxhov siab. Daim duab hauv qab no qhia txog cov txiaj ntsig kev ntxhov siab uas siv cov shear flow ramp-down method. Los ntawm cov txiaj ntsig kev xeem, nws tuaj yeem pom tau tias ntawm qhov nruab nrab ntawm cov nqi shear, qhov kev ntxhov siab shear txo qis thaum lub shear tus nqi txo. Txawm li cas los xij, thaum tus nqi qis dua ntxiv, qhov kev ntxhov siab nkhaus nce mus txog qib ruaj khov thiab tsis muaj kev ywj pheej ntawm tus nqi. Qhov kev ntxhov siab ruaj khov no yog hu ua qhov taw qhia tawm. Nyob rau tib lub sijhawm, qhov ntsuas "pom meej viscosity" nkhaus dhau los ua tsis kawg thiab muaj kev sib raug zoo nrog tus nqi shear thaum txoj kab nqes yog -1.
Txij li cov hluavtaws graphite muaj qhov loj me me thiab cov duab tsis sib xws ntau dua, cov slurry nthuav tawm cov kev ntxhov siab qis dua thiab cov qauv tsis muaj zog. Yog li ntawd, cov qauv hluavtaws graphite slurry no yuav raug cuam tshuam rau sedimentation thiab theem sib cais. Slurry sedimentation tuaj yeem ua rau tsis sib xws ntawm cov khoom siv hluav taws xob ntawm cov electrode, yog li txo cov roj teeb ua haujlwm.
(4) Thixotropy
Tom qab txheej, lub roj teeb slurry yuav nyob rau hauv qhov kev txiav txim ntawm lub ntiajteb txawj nqus thiab nto nro ntawm cov khoom tam sim no. Nyob rau hauv qhov tsawg shear npaum li cas, nws cia siab tias viscosity yuav maj mam rov qab mus rau siab viscosity ua ntej txheej. Ua ntej nws rov qab mus rau siab viscosity, lub viscosity ntawm slurry yog tseem qis, yooj yim rau theem, thiab txheej txheej yog du thiab uniform nyob rau hauv thickness. Lub sij hawm rov qab yuav tsum tsis txhob ntev los yog luv heev. Yog hais tias lub sij hawm rov qab ntev dhau lawm, lub viscosity ntawm slurry yuav tsawg dhau thaum lub sij hawm leveling txheej txheem, thiab nws yog ib qho yooj yim kom muaj tailing los yog lub thickness ntawm lub qis ntug yog siab tshaj lub thickness ntawm lub sab sauv txheej. Yog tias lub sijhawm luv luv, lub slurry yuav tsis muaj sijhawm rau qib.
2. Slurry resistance meter
Lub slurry resistivity parameter muaj ib qho tseem ceeb correlation nrog lub slurry mis, hom thiab cov ntsiab lus ntawm cov conductive tus neeg saib xyuas, hom thiab cov ntsiab lus ntawm cov ntaub ntawv, thiab lwm yam. tshwm sim, thiab tus nqi resistivity kuj yuav qhia txawv degrees ntawm kev hloov. Yog li ntawd, cov slurry resistivity tuaj yeem siv los ua ib txoj hauv kev los qhia qhov sib xws thiab kev ruaj ntseg ntawm slurry cov khoom hluav taws xob.
Txoj kev kuaj:Muab qee qhov ntim ntawm slurry (txog 80mL) rau hauv lub khob ntsuas, ntxig ib tus cwj mem huv electrode, pib lub software, kuaj qhov kev hloov ntawm slurry resistivity ntawm peb khub ntawm electrodes dhau sij hawm thiab txuag nws rau hauv daim ntawv.
Test tsis:resistivity, kub, sijhawm
Kev suav cov mis:Resistivity (Ω * cm): Ρe=U/I * S/L
Nta:
1. Sib cais cov kab hluav taws xob thiab cov kab tam sim no, tshem tawm cov kev cuam tshuam ntawm inductance ntawm qhov ntsuas hluav taws xob, thiab txhim kho qhov kev tiv thaiv kom pom tseeb.
2. Lub 10mm txoj kab uas hla disk electrode ua kom muaj kev sib cuag loj nrog cov qauv thiab txo qhov kev xeem yuam kev.
3. Lub resistivity hloov ntawm peb txoj hauj lwm nyob rau hauv txoj kab ntsug ntawm slurry nyob rau lub sij hawm tuaj yeem saib xyuas hauv lub sijhawm.
Resistivity ntsuas ntau yam:2.5Ω * cm ~ 50MΩ * cm
Resistivity ntsuas qhov tseeb:±0.5%
