Dab tsi yog npau suav phem tshaj plaws rau engineers txheej lithium roj teeb electrodes? Tej zaum pom freshly qhuav electrodes poob hmoov hnyav heev ntawm lub teeb kov. Ntug chipping thaum lub sij hawm slitting, roller sticking thaum lub sij hawm calendering, thiab txawm electrode snapping thaum winding -tag nrho cov teeb meem no taug qab mus rau ib lub hauv paus ua rau:CNTs tau "scavenged" lub binder.
CNTs muaj kev ua tau zoo heev, tab sis lawv muaj ob qho -edged zoo: ib qho chaw loj loj tshwj xeeb. Ib leeg-walled CNTs ncav cuag 800–1300 m²/g, thiab ntau-walled CNTs nyob ib ncig ntawm 180–210 m²/g. Xws li qhov chaw siab saum npoo tsim ntau qhov chaw adsorption, ua haujlwm zoo li daim txhuam cev muaj zog uas voraciously adsorbs nyob ze cov ntaub ntawv molecules -PVDF, SBR, CMC, tag nrho raug ntes.
Nrog rau cov ntaub qhwv los ntawm CNTs, cov ntaub ntawv tseem ceeb tsis tuaj yeem sib cog lus ruaj khov, yog li cov hmoov nplej thiab cov khoom poob ua yam tsis muaj. Niaj hnub no peb tau piav qhia meej txog cov txheej txheem thiab qhia txog yuav ua li cas kho qhov teeb meem los ntawm kev kho cov ntsiab lus binder thiab optimizing cov khoom noj kom zoo.
1. Cov nyhuv "Binder Black Hole" ntawm Carbon Nanotubes
Txhawm rau kom nkag siab cov hmoov nplej, koj yuav tsum xub nkag siab tias thaj chaw tshwj xeeb ntawm CNTs loj npaum li cas.
Raws li 1D nanomaterials, CNTs muaj ib txoj kab uas hla ntawm tsuas yog ob peb mus rau kaum nanometers tab sis ib tug ntev ntawm lub micron nplai, nrog ib tug nam piv feem ntau tshaj 1,000. Cov qauv no muab rau lawv qhov chaw siab heev. Kev tshawb fawb qhia tau hais tias vertically aligned CNT arrays muaj ib thaj tsam ntawm thaj tsam ntawm 600 m² / g, thaum dispersed ib leeg -walled CNTs yog ntau dua ntawm 800-1300 m² / g.
Kev sib piv: cov pa roj carbon dub muaj qhov tshwj xeeb ntawm thaj chaw ntawm ~ 60-80 m² / g, lub ntsiab lus CNTs adsorb10-20 npaug ntau dua binder moleculeslos ntawm qhov hnyav.
Thaum cov binder ntxiv rau slurry, kev sib tw tshwm sim: ob qho tib si cov khoom siv thiab CNT qhov chaw xav tau binder. CNTs yeej qhov kev sib tw no vim lawv qhov chaw tshwj xeeb loj thiab lub zog saum npoo av, khov kho adsorbing ntau cov ntaub ntawv rau hauv txheej txheej. Qhov tshwm sim:Cov ntaub ntawv tsis txaus txaus rau kev sib txuas cov khoom siv.
Cov kev tshawb fawb pom tias nanoparticles yooj yim re-agglomerate thaum lub sij hawm dispersion vim lawv cov morphology tshwj xeeb, uas tsis tsuas yog impairs conductivity tab sis kuj cuam tshuam kev sib raug zoo ntawm binders thiab active khoom. Qhov no yog lub physicochemical essence ntawm hmoov shedding.
2. Cov nyhuv Domino ntawm hmoov shedding
Binder adsorption los ntawm CNTs ua rau muaj kev sib txuas ntawm cov teeb meem:
Tsis txaus binder zoo: Cov khoom ua haujlwm tsis txaus "kua nplaum", txo cov electrode zog.
Tsis ruaj tsis khov conductive network: Binder adsorbed ntawm CNTs tsis muaj zog tiv tauj ntawm CNTs thiab lwm yam hais.
Nqaim txheej txheej txheem qhov rais: Hmoov-txiav electrodes muaj kev pheej hmoo siab ntawm kev txiav thiab tuag- txiav ntug.
Knock- ntawm cov teebmeem hauv cov txheej txheem hauv qab: Muaj kev pheej hmoo siab ntawm electrode breakage nyob rau hauv winding, degraded voj voog lub neej, thiab cuam tshuam lub roj teeb kev nyab xeeb.
Cov pa roj carbon monoxide tsis zoo txo cov electrode adhesion, ua rau cov hmoov ua kom muaj kev pheej hmoo ntawm kev txiav thiab tuag- txiav ntug, uas cuam tshuam cov electron conduction thiab nce electrochemical polarization.
Kev ua hmoov hmoov tsis yog qhov teeb meem zoo nkauj xwb- nws ncaj qha txiav txim siab qhov ua tau zoo ntawm cov roj teeb zaum kawg.
3. Tshuaj 1: Kho Cov Tshuaj Kho Mob
Txij li thaum CNTs haus cov ntaub ntawv ntxiv, qhov kho ncaj tshaj plaws yog losntxiv ntxiv.
Ntau npaum li cas? Kev lag luam kev paub qhia tau hais tias thaum CNT loading yog 0.5% -1.5%, binder ntau npaum yuav tsum tau nce los ntawm10%–30%. Qhov tseeb nce yog nyob ntawm CNT hom (ib zaug - lossis ntau-walled), thaj chaw tshwj xeeb, thiab cov khoom siv ua haujlwm.
Hauv kev tsim khoom, peb pom zoo rau kev kuaj gradient: kho CNT ntau npaum, kuaj electrode tev lub zog thiab hmoov los ntawm 5%, 10%, 15%, 20%, 25% siab dua binder qib, thiab nrhiav tus nqi zoo- taw tes ua haujlwm.
Qee cov tswv yim ntxiv cov pa roj carbon monoxide rau cov khoom siv slurry, uas txhim kho electrode electrolyte wettability, boosts cathode compaction thiab cheeb tsam ntom ntom, thiab tiv thaiv cov menyuam sticking thiab hmoov shedding. Qhov no kuj yog ib txoj hauv kev ua tau.
4. Kev daws 2: Txhim kho kev noj zaub mov kom zoo
Ntxiv binder yog ib qho "ntxiv ntxiv", thaum optimizing noj ib theem zuj zus yog "ntse ntxiv".
Kev xyaum ua ke sib xyaw tag nrho cov ntaub ntawv ib zaug lossis ntxiv CNTs ua ntej khi. Qhov no tso cai rau CNTs adsorb binder ua ntej, tawm hauv tsis muaj binder rau tom qab - ntxiv cov khoom siv.
Txoj kev raug yog muscia cov khoom siv "tau puv" ua ntej. Kev pom zoo stepwise pub mis yog raws li nram no:
Roj-raws li System (PVDF–NMP)
Ntxiv tag nrho PVDF rau hauv NMP thiab yaj tag nrho rau 2-3 teev.
Ntxiv cov roj carbon dub (yog tias siv) thiab sib tov sib xyaw.
Ntxiv cov khoom siv (piv txwv li, LiFePO₄, NCM) thiab tawg ntawm kev kub ceev.
Ntxiv CNT muab tshuaj txhuam zaum kawg thiab sib tov sib xyaw ntawm qhov nrawm.
Aqueous System (CMC-SBR)
Sib tov CMC nrog dej los npaj premix thiab do rau 3-5 teev.
Ntxiv cov khoom nquag thiab tawg ntawm kev kub ceev.
Ntxiv cov pa roj carbon dub thiab CNTs, ces disperse uniformly.
Ntxiv SBR kawg thiab do uniformly ntawm tsawg ceev.
Lub hauv paus ntsiab lus tseem ceeb: Cia cov binders tag nrho hu rau cov ntaub ntawv nquag ua ntej los tsim ib qho kev sib txuas ua ntej. Ntxiv CNTs kawg- feem ntau cov binder twb khi rau cov ntaub ntawv nquag, yog li CNT adsorption raug txwv thiab dispersion yuav yooj yim dua.
Lub tshuab patented siv cov hmoov tsis siv neeg pub mis ntxiv rau CNTs hauv ntau cov kauj ruam, txo qis cov viscosity ntawm siab -khoom CNT slurry thiab txhim kho kev ua haujlwm. Qhov no tsim nyog kawm los ntawm.
5. Kev daws 3: Siv Pre-paste dispersed
Dhau li ntawm cov qauv thiab cov txheej txheem hloov kho, qhov kev xaiv yooj yim dua yog sivua ntej -dispersed CNT conductive pastees tsis txhob tawg hmoov hauv - tsev.
Vim li cas? Cov txheej txheem hmoov dispersion nws tus kheej yog theem txaus ntshai tshaj plaws rau kev sib khi adsorption. Ib tus neeg muag khoom ua ntej- cov tshuaj nplaum dispersed nrog cov khoom sib xyaw ua ke zoo heev txo qis tshaj - adsorption txaus ntshai.
Raws li cov kws tshaj lij CNT chaw tsim khoom, peb nkag siab tob txog cov teeb meem hmoov ua rau cov neeg siv khoom qis. Yog li ntawd, peb muab tsis tau tsuas yog siab -purity CNT hmoov tab sis kuj ua ntej - dispersed conductive muab tshuaj txhuam. Nrog rau tus kheej- tsim cov tshuab dispersion thiab optimized feeding txheej txheem, peb xyuas kom meej tias CNTs nyob rau hauv txhua txhua batch yog stably dispersed ua ntej xa, txo cov hmoov los ntawm binder adsorption thaum lub sij hawm neeg siv.
Tanfeng Technology muaj tag nrho -kev lag luam- chain technology npog catalysts, hmoov, kua qaub ntxuav, thiab slurry. Rau ib zaug -CNT muab tshuaj txhuam phab ntsa, peb tus kheej- tsim cov tshuaj dispersants xa cov viscosity zoo dua thiab cov ntsiab lus zoo dua li cov khoom lag luam. Cov kws tshaj lij cov tuam txhab tuav cov txiaj ntsig zoo hauv kev xaiv dispersant thiab tswj cov txheej txheem.
Peb cov khoom lag luam suav nrog ntau-walled CNT hmoov, ib qho -walled CNT hmoov, thiab CNT conductive muab tshuaj txhuam. Ua los ntawm cov tshuaj vapor deposition (CVD), peb tswj cov tsis tseem ceeb (inch, nam piv, tshwj xeeb deg cheeb tsam) ntawm qhov chaw los txhawb kev ruaj ntseg daim ntawv thov. Peb kuj muab kev sab laj 24/7 los pab txhim kho cov qauv thiab cov txheej txheem, muab qhov tseeb - nres "khoom siv + kev pabcuam" kev daws teeb meem.
6. Cov lus pom zoo rau cov neeg siv
Yog tias koj tawm tsam nrog electrode hmoov shedding, sim cov kauj ruam no:
Tshawb xyuas CNT loading ntau dhau: CNTs muaj cov khoom siv ntau dua li cov pa roj carbon dub thiab feem ntau xav tau qis dua. Overloading ua rau muaj kev pheej hmoo.
Txheeb xyuas qhov kev noj zaub mov: Puas yog cov binders hu rau cov khoom siv ua ntej? Puas yog CNTs ntxiv kawg?
Test binder increment: Nce binder los ntawm 10% -20% raws li koj cov qauv tam sim no thiab soj ntsuam kev txhim kho.
Hloov mus rau ua ntej-paste dispersed: Yog tias hmoov dispersion tseem tsis ruaj khov, yuav ua ntej-dispersed paste kom tsis txhob muaj cov txheej txheem sim-thiab- yuam kev.
Electrode hmoov shedding zoo nkaus li yog ib qho teeb meem ntawm cov txheej txheem, tab sis hauv paus nws yog hais txog kev txuam CNT khoom nrog cov txheej txheem thov. Nkag siab txog qhov "binder black hole" cov nyhuv thiab kho qhov ntau npaum li cas thiab kev pub mis raws li yuav daws tau cov teeb meem hmoov ntau.
Yog tias koj tab tom nrhiav rau CNT hmoov los yog cov khoom siv tshuaj, lossis xav tau kev pab daws cov teeb meem hmoov av, thov hu rau peb. Raws li cov kws tsim khoom lag luam, peb pab tig qhov siab no - kev ua tau zoo tab sis "siab- tu" cov khoom rau hauv kev tsim khoom ruaj khov rau koj cov kab ntau lawm.