Nickel-cobalt-manganese ternary khoom yog ib qho ntawm cov khoom tseem ceeb ntawm cov roj teeb tam sim no. Peb lub ntsiab lus muaj cov ntsiab lus sib txawv rau cov khoom siv cathode, ntawm cov khoom siv nickel yog txhawm rau txhim kho lub peev xwm ntawm lub roj teeb. Qhov siab dua cov ntsiab lus nickel, ntau dua cov khoom siv tshwj xeeb muaj peev xwm. NCM811 muaj lub peev xwm tshwj xeeb ntawm 200mAh / g thiab lub tshuab tso tawm ntawm li 3.8V, uas tuaj yeem ua rau lub zog ceev ceev. Txawm li cas los xij, qhov teeb meem ntawm NCM811 roj teeb muaj kev nyab xeeb tsis zoo thiab lub neej voj voog ceev ceev. Dab tsi yog vim li cas cuam tshuam rau nws lub voj voog lub neej thiab kev nyab xeeb? Yuav daws qhov teeb meem no li cas? Cov hauv qab no yog ib qho kev ntsuam xyuas tob:

NCM811 tau tsim rau hauv pob roj teeb (NCM811 / Li) thiab hloov pauv pob roj teeb (NCM811 / graphite), thiab nws lub peev xwm gram thiab lub peev xwm roj teeb tau raug kuaj raws li. Lub roj teeb muag muag tau muab faib ua plaub pawg rau ib qho kev sim. Qhov sib txawv parameter yog txiav tawm voltage, uas yog 4.1V, 4.2V, 4.3V thiab 4.4V, feem. Ua ntej, lub roj teeb tau cycled ob zaug ntawm 0.05c thiab tom qab ntawd ntawm 0.2C ntawm 30 ℃. Tom qab 200 lub voj voog, lub pob muag roj teeb lub voj voog nkhaus yog qhia hauv daim duab hauv qab no:

Nws tuaj yeem pom los ntawm daim duab uas nyob rau hauv cov xwm txheej ntawm kev txiav tawm hluav taws xob siab, lub peev xwm gram ntawm cov teeb meem nyob thiab roj teeb yog ob qho tib si siab, tab sis lub peev xwm gram ntawm cov roj teeb thiab cov khoom siv kuj lwj sai dua. Ntawm qhov tsis sib xws, ntawm qhov kev txiav tawm qis dua (qis dua 4.2V), lub peev xwm roj teeb qis qis thiab lub neej voj voog ntev dua.

Hauv qhov kev sim no, cov tshuaj tiv thaiv kab mob tau kawm los ntawm isothermal calorimetry thiab cov qauv thiab morphology degradation ntawm cathode cov ntaub ntawv thaum lub caij tsheb kauj vab tau kawm los ntawm XRD thiab SEM. Cov lus xaus yog raws li nram no:

Daim duab

Ua ntej, kev hloov ntawm cov qauv tsis yog qhov ua rau lub roj teeb lub neej poob qis

Cov txiaj ntsig ntawm XRD thiab SEM tau pom tias tsis muaj qhov sib txawv ntawm qhov sib txawv ntawm cov qauv morphology thiab atomic qauv ntawm lub roj teeb nrog electrode thiab txiav tawm voltage ntawm 4.1V, 4.2V, 4.3V thiab 4.4V tom qab 200 cycles ntawm 0.2c. Yog li ntawd, kev hloov pauv sai ntawm cov teeb meem nyob hauv lub sijhawm them thiab tawm tsis yog qhov laj thawj tseem ceeb rau kev poob ntawm lub roj teeb lub neej. Hloov chaw, cov kab mob parasitic tshwm sim ntawm qhov sib cuam tshuam ntawm cov electrolyte thiab cov khoom muaj zog heev ntawm cov teeb meem nyob hauv lub xeev delithium yog lub ntsiab ua rau txo roj teeb lub neej ntawm 4.2V high voltage voj voog.

(1) SEM

Daim duab

Daim duab

A1 thiab A2 yog SEM cov duab ntawm lub roj teeb uas tsis muaj kev ncig. B ~ E yog SEM cov duab ntawm cov khoom siv hluav taws xob zoo tom qab 200 lub voj voog nyob rau hauv 0.5C mob thiab them nyiaj txiav tawm voltage ntawm 4.1V / 4.2V / 4.3V / 4.4V, feem. Sab laug yog electron microscope duab nyob rau hauv qis magnification thiab sab xis yog electron microscope duab nyob rau hauv siab magnification. Raws li tuaj yeem pom los ntawm daim duab saum toj no, tsis muaj qhov sib txawv tseem ceeb hauv particle morphology thiab breakage degree ntawm cov roj teeb circulating thiab cov roj teeb uas tsis yog circulating.

(2) XRD cov duab

Raws li tuaj yeem pom los ntawm daim duab saum toj no, tsis muaj qhov txawv txav ntawm tsib lub ncov hauv cov duab thiab txoj haujlwm.

(3) Hloov ntawm cov lattice parameter

Daim duab

Raws li tuaj yeem pom los ntawm lub rooj, cov ntsiab lus hauv qab no:

1. Lub lattice constants ntawm uncycled polar daim hlau yog raws li cov NCM811 nyob hmoov. Thaum lub voj voog txiav tawm voltage yog 4.1V, lub lattice tas li tsis sib txawv ntawm ob qho dhau los, thiab C axis nce me ntsis. Lub lattice tas li ntawm C-axis nrog 4.2V, 4.3V thiab 4.4V tsis txawv ntawm cov 4.1V (0.004 angms), thaum cov ntaub ntawv ntawm A-axis txawv heev.

2. Tsis muaj qhov hloov pauv tseem ceeb hauv Ni cov ntsiab lus hauv tsib pawg.

3. Polar daim hlau nrog ib tug circulating voltage ntawm 4.1V ntawm 44.5 ° nthuav dav FWHM, thaum lwm pab pawg tswj pom zoo FWHM.

Nyob rau hauv cov txheej txheem them thiab tso tawm ntawm lub roj teeb, C axis muaj qhov loj me me thiab nthuav dav. Qhov txo qis hauv lub roj teeb lub neej ntawm high voltages tsis yog vim muaj kev hloov pauv ntawm cov teeb meem hauv lub neej. Yog li ntawd, peb lub ntsiab lus saum toj no txheeb xyuas qhov kev hloov pauv ntawm cov qauv tsis yog qhov laj thawj tseem ceeb rau kev poob ntawm lub roj teeb lub neej.

Daim duab

Qhov thib ob, lub voj voog lub neej ntawm NCM811 roj teeb muaj feem xyuam rau cov tshuaj tiv thaiv kab mob hauv lub roj teeb

NCM811 thiab graphite yog tsim rau hauv cov pob txha hloov tau siv cov electrolytes sib txawv. Nyob rau hauv sib piv, 2% VC thiab PES211 tau ntxiv rau electrolyte ntawm ob pawg, raws li, thiab lub peev xwm txij nkawm tus nqi ntawm ob pawg tau pom qhov sib txawv loj tom qab lub roj teeb.

Daim duab

Raws li daim duab saum toj no, thaum txiav tawm hluav taws xob ntawm lub roj teeb nrog 2% VC yog 4.1V, 4.2V, 4.3V thiab 4.4V, lub peev xwm tu tus nqi ntawm lub roj teeb tom qab 70 cycles yog 98%, 98%, 91 % thiab 88%, feem. Tom qab tsuas yog 40 lub voj voog, lub peev xwm tu tus nqi ntawm lub roj teeb nrog ntxiv PES211 txo qis rau 91%, 82%, 82%, 74%. Qhov tseem ceeb, hauv kev sim yav dhau los, lub roj teeb lub neej ntawm NCM424 / graphite thiab NCM111 / graphite systems nrog PES211 yog qhov zoo dua li nrog 2% VC. Qhov no ua rau qhov kev xav tias cov khoom siv electrolyte muaj qhov cuam tshuam loj rau lub roj teeb lub neej hauv cov tshuab nickel siab.

Nws tseem tuaj yeem pom los ntawm cov ntaub ntawv saum toj no tias lub voj voog lub neej nyob rau hauv high voltage yog qhov phem dua li qhov qis qis. Los ntawm kev ua haujlwm haum ntawm polarization, △V thiab lub sijhawm voj voog, cov duab hauv qab no tuaj yeem tau txais:

Daim duab

Nws tuaj yeem pom tias lub roj teeb △V me me thaum caij tsheb kauj vab ntawm qhov hluav taws xob qis qis, tab sis thaum qhov hluav taws xob nce siab tshaj 4.3V, △V nce siab heev thiab lub roj teeb polarization nce, uas cuam tshuam rau lub roj teeb lub neej. Nws kuj tseem tuaj yeem pom los ntawm daim duab uas △V hloov pauv tus nqi ntawm VC thiab PES211 yog qhov sib txawv, uas ntxiv kev tshawb xyuas ntxiv tias cov degree thiab ceev ntawm roj teeb polarization txawv nrog cov khoom siv electrolyte sib txawv.

Isothermal microcalorimetry tau siv los txheeb xyuas cov kab mob parasitic tshwm sim ntawm lub roj teeb. Cov tsis xws li polarization, entropy thiab parasitic heat flow tau muab rho tawm los ua kev sib raug zoo nrog rSOC, raws li qhia hauv daim duab hauv qab no:

Daim duab

Saum toj no 4.2V, cov kab mob parasitic thaum tshav kub kub yog qhia kom nce dheev, vim hais tias lub siab delithium anode nto reacts yooj yim nrog cov electrolyte ntawm high voltage. Qhov no kuj piav qhia tias yog vim li cas tus nqi hluav taws xob ntau dua thiab qhov hluav taws xob tawm, qhov ceev ntawm lub roj teeb tu tus nqi txo.

Daim duab

Iii. NCM811 muaj kev ruaj ntseg tsis zoo

Nyob rau hauv qhov xwm txheej ntawm qhov kub thiab txias, cov tshuaj tiv thaiv ntawm NCM811 hauv lub xeev them nrog electrolyte yog ntau dua li ntawm NCM111. Yog li ntawd, kev siv NCM811 cov roj teeb yog qhov nyuaj kom dhau lub teb chaws yuav tsum tau ntawv pov thawj.

Daim duab

Daim duab yog ib daim duab ntawm tus kheej cua sov tus nqi ntawm NCM811 thiab NCM111 ntawm 70 ℃ thiab 350 ℃. Daim duab qhia tau hais tias NCM811 pib kub txog li 105 ℃, thaum NCM111 tsis txog 200 ℃. NCM811 muaj qhov cua sov ntawm 1 ℃ / min los ntawm 200 ℃, thaum NCM111 muaj cua sov ntawm 0.05 ℃ / min, uas txhais tau hais tias NCM811 / graphite system nyuaj kom tau txais ntawv pov thawj kev nyab xeeb yuav tsum tau ua.

High nickel nyob teeb meem yog khi ua cov khoom tseem ceeb ntawm lub zog siab ceev roj teeb yav tom ntej. Yuav daws qhov teeb meem ntawm kev lwj sai ntawm NCM811 roj teeb lub neej li cas? Ua ntej, qhov seem ntawm NCM811 tau hloov kho los txhim kho nws cov kev ua tau zoo. Qhov thib ob yog siv cov electrolyte uas tuaj yeem txo cov kab mob parasitic ntawm ob, txhawm rau txhim kho nws lub neej voj voog thiab kev nyab xeeb. Daim duab

Ntev nias txhawm rau txheeb xyuas QR code, ntxiv lithium π!

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