Lithium ion roj teeb electrolyte hom

Lithium ion roj teeb electrolyte hom

1.1 kua roj electrolyte

Qhov kev xaiv ntawm electrolyte muaj kev cuam tshuam zoo heev rau kev ua tau zoo ntawm cov roj teeb lithium ion. Nws yuav tsum muaj cov tshuaj ruaj khov zoo, tshwj xeeb tshaj yog qhov siab dua thiab qhov kub siab dua, thiab muaj cov neeg taug lw dua qub (> 10-3). ? S / cm), thiab yuav tsum tsis ncaj ncees rau cov ntaub ntawv anode thiab cathode, tsis tuaj yeem cuam tshuam rau lawv. Txij li cov roj teeb uas muaj lithium ion muaj peev xwm thiab muaj peev xwm thiab cov khoom siv anode yog kos nrog ib hom tshuaj muaj zog, cov electrolyte yuav tsum siv cov organic compound thiab tsis tuaj yeem muaj dej. Txawm li cas los xij, txoj kab xo kab mob ntawm cov organic teeb meem tsis zoo, yog li cov tshuaj ua muaj zog ntsev ntxiv rau cov organic ua kom muaj zog rau cov kab xev. Tam sim no, cov roj lithium-ion yog siv los ua cov electrolytes. Cov kuab tshuaj yog anhydrous organic tshuaj xws li EC, PC, DMC, DEC, thiab feem ntau lawv siv mixed solvents xws li EC / DMC thiab PC / DMC. Cov cwj pwm uas muaj ciaj sia yog LiClO? 4, LiPF6, LiBF6, LiAsF6, thiab lwm yam, thiab lawv cov conductivity yog ib zaug LiAsF6> LiPF6> LiClO? 4> LiBF6. LiClO4 yog ib qho yooj yim rau kev tawg thiab lwm yam teeb meem kev nyab xeeb vim nws qhov siab oxidizing cuab yeej. Nws tsuas yog siv rau kev sim tshawb nrhiav xwb. LiAsF6 muaj siab ion conductivity thiab yog ib qho yooj yim purify thiab muaj stability stability, tab sis muaj tshuaj lom Muaj, uas muaj kev txwv hauv kev siv; LiBF6 Chemistry Thiab lub thermal stability tsis zoo thiab cov conductivity tsis siab. Txawm hais tias LiPF6 yuav ua raws li kev txiav txim siab, nws muaj cov neeg muaj siab coj los ua ke, yog li cov lithium ion roj yeej siv LiPF6. Tam sim no, feem ntau cov electrolytes siv hauv cov roj teeb lithium ion roj teeb siv lub EC / DMC ntawm LiPF6, uas muaj siab ionic conductivity thiab ruaj ntseg zoo electrochemical.

2.2 txheem ntawm electrolyte

Kev siv cov pa roj carbon dioxide ncaj qha raws li ib qho khoom siv anode muaj peev txheej siab, thiab nws qhov peev xim yog li 3862 mAh · g-1, uas yog ntau tshaj kaum lub sij hawm ntawm graphite cov ntaub ntawv, thiab tus nqi tseem tsawg, uas yog poob siab tias kev pom zoo ntawm ib tiam tshiab ntawm lithium ion roj teeb. Cov khoom siv anode yuav tsim cov tshuaj dithritic lithium. Kev siv cov khoom siv electrolyte raws li txoj cai ntawm ions tuaj yeem loj hlob ntawm dithritic lithium, ua rau nws siv tau cov xim hlau lithium ua ib qho anode khoom. Tsis tas li ntawd, kev siv cov tshuaj electrolyte tsis zoo rau qhov tsis zoo ntawm cov roj ntsha ntau dhau lawm, thiab lub roj teeb yuav ua rau thinner (tsuas yog 0.1 hli tuab) cov roj hluav taws xob uas muaj zog dua thiab muaj zog dua. Cov kev puas tsuaj uas ua rau muaj kev puas tsuaj pom tau tias cov roj ntsha-lithium-ion muaj peev xwm ua tau zoo. Tom qab xa dej, cua kub (200 ° C), luv luv thiab ntau dua (600%) thiab lwm yam kev sim, kua roj ntsha kua roj ntsha kua qaub xau yuav tawg thiab tawg. Cov teeb meem ntawm kev sib deev, thaum cov roj teeb muaj lub cev tsis muaj teeb meem ntawm kev nyab xeeb tshwj tsis yog tias muaj kev kub ntxhov hauv qhov kub (<20 °=""> Khoom noj khoom haus polymer electrolytes muaj kev ywj pheej zoo, moldability, stability, thiab luv nqi. Nws tuaj yeem raug siv los ua ib qho zoo thiab tsis zoo ntawm cov hlau electrode spacer zaj duab xis thiab ua ib qho khoom ua electrolyte rau ion thauj.

Khoom siv hluav taws xob polymer electrolytes feem ntau muab cais ua rau hauv lub cev qhuav polymer electrolyte (SPE) thiab ib cov gel polymer electrolyte (GPE). SPE khoom polymer electrolytes yog los ntawm polyethylene oxide (PEO), uas muaj qhov tsis zoo ntawm cov neeg tsis muaj kev xyuam xim thiab tsuas tuaj yeem ncav cuag 10-40 cm ntawm 100 ° C. Hauv SPE, txoj kev xa xov hluav taws xob tshwm sim feem ntau hauv cheeb tsam amorphous, thiab kev thauj yog pauv los ntawm kev txav ntawm txoj kab saw polymer. PEO yog yooj yim crystallized vim lub siab li niaj zaus ntawm nws cov yeeb yaj duab molecular, thiab crystallisation thiaj li ua rau cov neeg muaj keebkwm (conductivity). Yog li, thiaj li yuav ua rau kom cov neeg muaj suab npe zoo, ntawm ib sab tes, nws muaj peev xwm los txo cov neeg muaj keeb kwm zoo. Yog li ntawd, los txhim kho cov teebmeem ionic, ntawm ib tes, los ntawm kev txo cov solubility ntawm lub polymer. Grafting, thaiv, ntoo sib txuas, kev sib txuas sib txuas thiab cov zoo li siv los ua kom muaj kev tshaib plab ntawm lub polymer, thiab txoj kab tshooj ionic yuav ua tau zoo dua. Tsis tas li ntawd, qhov sib ntxiv ntawm ib qho ntsev tsis muaj zog hauv cov ntsev kuj tuaj yeem ua rau cov neeg muaj keeb kwm zoo tuaj. Ntxiv ib lub dielectric siab tsawg molecular nyhav kua organic hnyav xws li PC rau cov khoom polymer electrolyte tau zoo heev txhim kho lub solubility ntawm cov conductive ntsev. Cov khoom siv electrolyte yog ib lub GPE gel polymer electrolyte, uas muaj kev ntsuas kub ntawm chav sov. Ionic conductivity, tab sis liquidation yuav tsis thaum siv. Gel polymer lithium ion roj tau commercialized.