CMC siv hauv Kev Lag Luam Roj Teeb

Dab tsi yog sodium carboxymethyl cellulose?

Sodium Carboxymethyl cellulose, (tseem hu ua: Carboxymethyl cellulose sodium ntsev, Carboxymethyl cellulose, CMC, Carboxymethyl, CelluloseSodium, SodiumsaltofCaboxyMethylCellulose) yog lub ntiaj teb siv ntau hom fiber ntau, ntau npaum li cas.

Cmc-na yog cellulose derivative nrog ib tug polymerization degree ntawm 100 ~ 2000 thiab molecular hnyav ntawm 242.16. Dawb fibrous los yog granular hmoov. Tsis muaj ntxhiab, tsis qab, tsis qab, hygroscopic, insoluble hauv cov kuab tshuaj organic. Daim ntawv no tsuas yog nkag siab txog daim ntawv thov ntawm sodium carboxymethyl cellulose hauv lithium ion roj teeb cov ntsiab lus.

Kev nce qib hauv kev siv Sodium carboxymethyl cellulose CMChauv cov roj teeb lithium ion

Tam sim no, polyvinylidene fluoride [pVDF, (CH: A CF:)] yog siv dav hauv kev tsim cov roj teeb lithium ion. . PVDF tsis yog tsuas yog kim, kuj yuav tsum tau siv nyob rau hauv tus txheej txheem ntawm daim ntawv thov ntawm tawg, tus phooj ywg rau ib puag ncig ntawm organic solvents, xws li N methyl uas cov alkane ketone (NMp) thiab huab cua humidity yuav tsum tau rau cov txheej txheem ntau lawm nruj me ntsis, kuj yooj yim nrog embedded. hlau lithium, lithium graphite theem nrab cov tshuaj tiv thaiv, tshwj xeeb tshaj yog nyob rau hauv cov xwm txheej ntawm kub siab, ib tug spontaneous kev pheej hmoo ntawm thermal runaway. Sodium carboxymethyl cellulose (CMC), cov dej-soluble binder, yog siv los hloov pVDF rau cov khoom siv electrode, uas tuaj yeem zam kev siv NMp, txo cov nqi thiab txo cov pa phem ib puag ncig. Nyob rau tib lub sijhawm, cov txheej txheem tsim khoom tsis tas yuav muaj cov av noo ib puag ncig, tab sis kuj tuaj yeem txhim kho lub peev xwm ntawm lub roj teeb, ua kom lub neej ntev. Hauv daim ntawv no, lub luag haujlwm ntawm CMC hauv kev ua haujlwm ntawm lithium ion roj teeb tau raug tshuaj xyuas, thiab cov txheej txheem ntawm CMC txhim kho cov roj teeb kev ua tau zoo tau sau los ntawm cov yam ntxwv ntawm thermal stability, hluav taws xob conductivity thiab electrochemical yam ntxwv.

1. Cov qauv thiab kev ua haujlwm ntawm CMC

1) CMC qauv

CMC feem ntau yog cais los ntawm ntau qib kev hloov pauv (Ds), thiab cov khoom lag luam morphology thiab kev ua tau zoo cuam tshuam los ntawm Ds. LXi et al. kawm CMC nrog Ds sib txawv H khub ntawm Na. SEM tsom xam cov txiaj ntsig tau pom tias CMC-Li-1 (Ds = 1.00) nthuav tawm cov qauv granular, thiab CMC-Li-2 (Ds = 0.62) nthuav tawm cov qauv linear. Kev tshawb fawb ntawm M. E thiab al ua pov thawj tias CMC. Styrene butadiene roj hmab (SBR) tuaj yeem cuam tshuam cov agglomeration ntawm Li: O thiab stabilize lub interface qauv, uas muaj txiaj ntsig zoo rau kev ua haujlwm ntawm electrochemical.

2) CMC kev ua haujlwm

2.1)Thermal stability

Zj Han et al. kawm cov thermal stability ntawm txawv binders. Qhov kub tseem ceeb ntawm pVDF yog li 4500C. Thaum ncav cuag 500 ℃, sai decomposition tshwm sim thiab qhov loj yog txo los ntawm 70%. Thaum qhov kub thiab txias mus txog 600 ℃, qhov loj tau ntxiv los ntawm 70%. Thaum qhov kub txog 300oC, qhov loj ntawm CMC-Li raug txo los ntawm 70%. Thaum kub txog 400 ℃, qhov loj ntawm CMC-Li raug txo los ntawm 10%. CMCLi yog yooj yim decomposed dua pVDF thaum kawg ntawm roj teeb lub neej.

2.2)Hluav taws xob conductivity

S. Chou et al. Cov txiaj ntsig kev xeem tau pom tias qhov kev tiv thaiv ntawm CMCLI-1, CMC-Li-2 thiab pVDF yog 0.3154 Mn·m thiab 0.2634 Mn, raws li. M thiab 20.0365 Mn·m, qhia tias qhov kev tiv thaiv ntawm pVDF yog siab dua li ntawm CMCLi, qhov conductivity ntawm CMC-LI zoo dua li ntawm pVDF, thiab cov conductivity ntawm CMCLI.1 yog qis dua CMCLI.2.

2.3)Electrochemical kev ua tau zoo

FM Courtel et al. tau kawm txog cyclic voltammetry curves ntawm poly-sulfonate (AQ) raws li electrodes thaum sib txawv binderswere siv. Cov binders sib txawv muaj qhov sib txawv oxidation thiab txo cov tshuaj tiv thaiv, yog li lub ncov muaj peev xwm sib txawv. Ntawm lawv, lub peev xwm oxidation ntawm CMCLi yog 2.15V, thiab qhov txo qhov peev xwm yog 2.55V. Lub peev xwm oxidation thiab txo qhov peev xwm ntawm pVDF yog 2.605 V thiab 1.950 V feem. Piv nrog rau lub voj voog voltammetry nkhaus ntawm ob zaug dhau los, lub ncov muaj peev xwm sib txawv ntawm oxidation-txo ncov thaum CMCLi binder tau siv me dua li thaum siv pVDF, qhia tias cov tshuaj tiv thaiv tsis tshua muaj kev cuam tshuam thiab CMCLi binder tau zoo dua rau qhov tshwm sim ntawm oxidation-txo cov tshuaj tiv thaiv.

2. Kev siv cov nyhuv thiab cov txheej txheem ntawm CMC

1) Cov nyhuv siv

Pj Suo et al. tau kawm cov electrochemical kev ua tau zoo ntawm Si / C cov ntaub ntawv sib xyaw thaum pVDF thiab CMC tau siv los ua cov ntawv khi, thiab pom tias lub roj teeb uas siv CMC muaj peev xwm thim rov qab ntawm 700mAh / g thawj zaug thiab tseem muaj 597mAh / g tom qab 4O cycles, uas yog superior rau lub roj teeb siv pVDF. Jh Lee et al. tau kawm txog kev cuam tshuam ntawm Ds ntawm CMC ntawm kev ruaj ntseg ntawm graphite ncua kev kawm ntawv thiab ntseeg hais tias cov kua zoo ntawm kev ncua yog txiav txim los ntawm Ds. Thaum qis DS, CMC muaj zog hydrophobic zog, thiab tuaj yeem ua rau cov tshuaj tiv thaiv nrog graphite nto thaum dej siv los ua xov xwm. CMC kuj muaj qhov zoo hauv kev tswj xyuas kev ruaj ntseg ntawm cov khoom siv hluav taws xob ntawm silicon - tin alloy anode cov ntaub ntawv. Cov NiO electrodes tau npaj nrog ntau qhov sib txawv (0.1mouL, 0.3mol / L thiab 0.5mol / L) CMC thiab pVDF binder, thiab them thiab tawm ntawm 1.5-3.5V nrog rau tam sim no ntawm 0.1c. Thaum thawj lub voj voog, lub peev xwm ntawm pVDF binder cell yog siab dua li ntawm CMC binder cell. Thaum tus naj npawb ntawm cov voj voog mus txog lO, lub peev xwm tawm ntawm pVDF binder txo qis. Tom qab 4JD cycles, qhov tshwj xeeb tso tawm muaj peev xwm ntawm 0.1movL, 0.3MOUL thiab 0.5MovLPVDF binders txo mus rau 250mAh / g, 157mAtv 'g thiab 102mAh / g, ntsig txog: Qhov tso tawm tshwj xeeb ntawm cov roj teeb nrog 0.1 moL / liter thiab 0.5 moL / LCMC binder tau khaws cia ntawm 698mAh / g, 555mAh / g thiab 550mAh / g, feem.

CMC binder yog siv rau ntawm LiTI0. : thiab SnO2 nanoparticles hauv kev tsim khoom. Siv CMC li binder, LiFepO4 thiab Li4TI50l2 raws li cov ntaub ntawv zoo thiab tsis zoo, raws li, thiab siv pYR14FS1 raws li nplaim hluav taws xob electrolyte, lub roj teeb tau cycled 150 zaug ntawm qhov tam sim no ntawm 0.1c ntawm 1.5v ~ 3.5V ntawm qhov kub thiab txias, thiab qhov zoo tshwj xeeb capacitance tau khaws cia ntawm 140mAh / g. Ntawm ntau cov ntsev ntsev hauv CMC, CMCLi qhia txog lwm cov hlau ions, uas tuaj yeem cuam tshuam "kev sib pauv tshuaj tiv thaiv (vii)" hauv electrolyte thaum ncig.

2) Mechanism ntawm kev txhim kho kev ua haujlwm

CMC Li binder tuaj yeem txhim kho kev ua haujlwm ntawm electrochemical ntawm AQ puag electrode hauv lithium roj teeb. M. E et al. -4 tau ua qhov kev tshawb fawb ua ntej ntawm lub tshuab thiab tau npaj cov qauv ntawm kev faib tawm ntawm CMC-Li hauv AQ electrode. Qhov kev ua tau zoo ntawm CMCLi los ntawm kev sib koom ua ke muaj zog ntawm hydrogen bonds tsim los ntawm OH, uas ua rau muaj txiaj ntsig zoo ntawm cov qauv mesh. Lub hydrophilic CMC-Li yuav tsis yaj nyob rau hauv cov organic electrolyte, yog li nws muaj ib tug zoo stability nyob rau hauv lub roj teeb, thiab muaj zog adhesion rau lub electrode qauv, uas ua rau lub roj teeb muaj ib tug zoo stability. Cmc-li binder muaj Li conductivity zoo vim tias muaj ntau pawg ua haujlwm ntawm cov saw molecular ntawm CMC-Li. Thaum tso tawm, muaj ob qhov chaw ntawm cov tshuaj muaj txiaj ntsig zoo nrog Li: (1) Li hauv electrolyte; (2) Li ntawm cov saw molecular ntawm CMC-Li nyob ze ntawm qhov chaw zoo ntawm cov khoom siv.

Cov tshuaj tiv thaiv ntawm pawg hydroxyl thiab pawg hydroxyl nyob rau hauv carboxymethyl CMC-Li binder yuav tsim covalent daim ntawv cog lus; Raws li qhov kev txiav txim ntawm lub zog hluav taws xob, U tuaj yeem hloov mus rau ntawm cov saw hlau molecular lossis cov saw hlau uas nyob ib sab, uas yog, cov qauv saw molecular yuav tsis raug puas tsuaj; Thaum kawg, Lj yuav khi rau AQ particle. Qhov no qhia tau hais tias daim ntawv thov ntawm CMCLi tsis tsuas yog txhim kho kev hloov pauv ntawm Li, tab sis kuj txhim kho kev siv tus nqi ntawm AQ. Cov ntsiab lus siab dua ntawm ch: COOLi thiab 10Li hauv cov saw hlau molecular, qhov yooj yim hloov Li. M. Armand et al. ntseeg hais tias cov organic tebchaw ntawm -COOH los yog OH tuaj yeem hnov ​​​​mob nrog 1 Li feem thiab tsim 1 C00Li lossis 1 0Li ntawm lub peev xwm tsawg. Txhawm rau txhawm rau tshawb nrhiav ntxiv cov txheej txheem ntawm CMCLi binder hauv electrode, CMC-Li-1 tau siv los ua cov khoom siv thiab cov lus xaus zoo sib xws tau txais. Li reacts nrog ib tug ch, COOH thiab ib tug 0H los ntawm CMC Li thiab generates cH: COOLi thiab ib tug 0 "feem ntau, raws li qhia nyob rau hauv equations (1) thiab (2)

Raws li tus naj npawb ntawm cH, COOLi, thiab OLi nce, DS ntawm CMC-Li nce. Qhov no qhia tau hais tias cov organic txheej tsim los ntawm AQ particle nto binder ua ntau ruaj khov thiab yooj yim rau hloov Li. CMCLi yog cov khoom siv hluav taws xob uas muab txoj hauv kev thauj mus rau Li kom ncav cuag AQ hais. CMCLi binders muaj cov khoom siv hluav taws xob zoo thiab ionic conductivity, uas ua rau kev ua haujlwm zoo electrochemical thiab lub neej ntev ntawm CMCLi electrodes. JS Bridel et al. npaj cov anode ntawm lithium ion roj teeb siv silicon / carbon / polymer composite cov ntaub ntawv nrog sib txawv binders los kawm txog kev cuam tshuam ntawm silicon thiab polymer ntawm tag nrho cov kev ua tau zoo ntawm lub roj teeb, thiab pom tias CMC muaj qhov zoo tshaj plaws kev ua tau zoo thaum siv los ua binder. Muaj kev sib raug zoo hydrogen ntawm silicon thiab CMC, uas muaj peev xwm kho tus kheej thiab tuaj yeem kho qhov kev ntxhov siab ntawm cov khoom siv thaum lub sij hawm caij tsheb kauj vab kom muaj kev ruaj ntseg ntawm cov khoom siv. Nrog CMC ua binder, lub peev xwm ntawm silicon anode tuaj yeem khaws cia siab tshaj 1000mAh / g hauv tsawg kawg yog 100 cycles, thiab coulomb efficiency yog ze rau 99.9%.

3, xaus

Raws li ib tug binder, CMC cov ntaub ntawv yuav siv tau nyob rau hauv ntau hom electrode cov ntaub ntawv xws li ntuj graphite, meso-phase carbon microspheres (MCMB), lithium titanate, tin raws li silicon raws li anode khoom thiab lithium hlau phosphate anode khoom, uas yuav txhim khu lub roj teeb. muaj peev xwm, voj voog stability thiab lub voj voog lub neej piv nrog pYDF. Nws muaj txiaj ntsig zoo rau thermal stability, hluav taws xob conductivity thiab electrochemical khoom ntawm CMC cov ntaub ntawv. Muaj ob lub ntsiab mechanisms rau CMC los txhim kho kev ua tau zoo ntawm lithium ion roj teeb:

(1) Kev ua haujlwm ruaj khov ntawm CMC tsim qhov tsim nyog yuav tsum tau ua ua ntej kom tau txais cov roj teeb ruaj khov;

(2) CMC muaj cov khoom siv hluav taws xob zoo thiab ion conductivity thiab tuaj yeem txhawb nqa Li hloov