Cov nyhuv ntawm VC Cov ntsiab lus hauv Electrolyte ntawm Lithium Iron Phosphate

Vinylene Carbonate (VC) muaj qhov hloov tau zoo heev rau qhov kub thiab txias. Ntxiv VC rau cov electrolyte tuaj yeem pab tsim ib txheej SEI ruaj khov rau ntawm qhov chaw ntawm cov anode hauv lithium roj teeb. Yog li, cov ntsiab lus ntawm VC muaj qhov cuam tshuam loj rau kev ua haujlwm ntawm lithium hlau phosphate (LiFePO₄) roj teeb. Daim ntawv no tshwj xeeb kawm txog cov txiaj ntsig ntawm VC cov ntsiab lus ntawm kev ua haujlwm electrochemical ntawm LiFePO₄ roj teeb nyob rau hauv qis- qhov kub thiab txias. LiFePO₄ roj teeb tau siv dav hauv cov tsheb tshiab thiab lub zog cia vim lawv txoj kev nyab xeeb siab, lub neej voj voog ntev, kev phooj ywg ib puag ncig, thiab tus nqi qis. Txawm li cas los xij, lawv ntsib teeb meem xws li kev tso tawm muaj peev xwm lwj thiab txo lub zog tuav ntawm qhov kub thiab txias (tshwj xeeb tshaj yog qis dua -20 degree), uas txwv tsis pub lawv siv hauv thaj chaw txias. Txhawm rau daws qhov teeb meem no, cov khoom siv ntxiv zoo li VC feem ntau ntxiv rau cov electrolyte los txhim kho qis -kub ionic conductivity, suppress sab kev xav, thiab stabilize lub electrode interface, yog li txhim kho lub roj teeb qhov kub thiab txias.

Hauv txoj kev tshawb no, plaub hom LiFePO₄ roj teeb electrolytes nrog cov ntsiab lus VC sib txawv (3.0%, 3.2%, 3.5%, 3.8%) tau npaj thiab sib sau ua ke rau hauv lub hnab ntim. Lub cathode siv LiFePO₄, thiab cov anode siv dag graphite. Tag nrho cov roj teeb tau npaj raws li cov txheej txheem tib yam thiab tau tsim thiab muaj peev xwm dispersion. Kev ntsuas hluav taws xob hluav taws xob tau ua rau txhua pawg roj teeb ntawm -30℃kom sib piv cov ntsuas kev ua haujlwm tseem ceeb xws li qhov ntsuas kub qis, qhov hluav taws xob ncaj qha tam sim no (DCR), kev siv hluav taws xob, thiab lub neej voj voog.

1. Tsawg-Tsub Muaj Peev Xwm Tshem Tawm

Los ntawm kev sim CV nkhaus ntawm lub roj teeb nyob rau hauv qis - qhov kub thiab txias thiab xam cov roj teeb muaj peev xwm los ntawm thaj chaw sib xyaw ntawm CV nkhaus.

Thaum cov ntsiab lus VC yog 3.5%, lub roj teeb qhia tau tias muaj peev xwm tawm tau siab tshaj plaws ntawm -30℃(5.6 Ah), zoo dua li lwm pab pawg (3.0%, 3.2%, thiab 3.8% sib haum rau 4.6 Ah, 5.0 Ah, thiab 5.0 Ah, feem). Tus nqi tsim nyog ntawm VC tuaj yeem txo qhov chaw khov ntawm cov electrolyte, nce ion txav mus los, thiab txo cov kuab tshuaj crystallization, yog li txhim kho kev ua haujlwm qis qis.

2. Direct Current Resistance (DCR)

DCR cov kev ntsuam xyuas ntawm lub roj teeb qhia tau hais tias thaum VC cov ntsiab lus yog 3.5%, DCR yog qis tshaj (0.76 mΩ), qhia tau hais tias qis interfacial tsis kam thiab siab dua lithium{2}} ion thauj efficiency. Cov ntsiab lus VC ntau dhau (piv txwv li, 3.8%) ua rau muaj kev nce ntxiv hauv DCR, qhia tias VC ntau dhau tuaj yeem ua rau muaj kev cuam tshuam cuam tshuam.

3. Tsawg-Tsub Zog Zog Efficiency

Thaum cov ntsiab lus VC yog 3.5%, lub roj teeb pom kev ua haujlwm siab tshaj plaws ntawm -30℃(82.0%), tshaj lwm pab pawg (72.5% ~ 79.0%). Qhov no yog ntaus nqi rau VC txhawb kev tsim ntawm ib tug ruaj khov SEI zaj duab xis, txo polarization poob, thiab pab txhawb zog conversion efficiency.

4. Lub neej voj voog

Tom qab 300 lub voj voog, lub roj teeb nrog 3.5% VC cov ntsiab lus qhia tau tias muaj peev xwm tuav tau siab tshaj plaws (97.5%), ua tau zoo dua lwm pab pawg (90.0% ~ 96.1%). VC tuaj yeem txhim kho SEI zaj duab xis tsis xws luag thaum caij tsheb kauj vab, inhibit electrolyte decomposition thiab roj tsim, yog li txuas ntxiv lub roj teeb lub neej ntawm qhov kub thiab txias.

ACEY-BA3040-20roj teeb lub voj voog kuaj khoom sivyog siv los ntsuam xyuas lub neej ntev, kev cia siab, muaj peev xwm thiab lwm yam tsis zoo ntawm lub roj teeb pob los ntawm kev ntsuas hluav taws xob thiab kev ntsuas tawm.

• VC nyiam txo rau ntawm graphite anode nto ua ntej cov kuab tshuaj molecules thaum lub sij hawm pib them thiab tawm cov txheej txheem, tsim ib tug ntom SEI zaj duab xis nplua nuj nyob rau hauv inorganic Cheebtsam xws li Li₂CO₃. Cov yeeb yaj kiab no muaj cov lithium siab heev-ion diffusion coefficient.

• Tus nqi tsim nyog ntawm VC tuaj yeem txhim kho cov qauv kev daws teeb meem ntawm cov electrolyte, txo cov viscosity, thiab txhim kho ionic conductivity ntawm qhov kub thiab txias.

• Ntau dhau VC tuaj yeem ua rau SEI zaj duab xis tuab dhau los lossis nce impedance, uas ua rau muaj kev puas tsuaj rau kev txhim kho kev ua haujlwm.

Txawm hais tias tsab xov xwm tau ua qhov kev sim sib piv sib txawv ntawm VC thiab ua qee qhov kev sim, txheeb xyuas cov ntsiab lus VC zoo hauv qhov kev sim no, nws tsis suav nrog pawg tswj tsis muaj VC. Yog li, nws tsis tuaj yeem txiav txim siab tias ntxiv VC yuav tsum txhim kho lub roj teeb ua haujlwm.