ESM: Ua-nyob rau hauv ultra-conformal interface ntawm perfluorinated electrolyte rau cov tswv yim siab-zog lithium roj teeb

Kev tshawb fawb keeb kwm

Hauv cov roj teeb lithium-ion, kom ua tiav lub hom phiaj ntawm 350 Wh Kg-1, cov khoom siv cathode siv cov nickel-nplua nuj txheej oxide (LiNixMnyCozO2, x + y + z = 1, hu ua NMCxyz). Nrog rau qhov nce ntawm lub zog ceev, cov kev piam sij cuam tshuam nrog thermal runaway ntawm LIBs tau nyiam cov neeg mloog. Los ntawm cov khoom xaav, nickel-nplua nuj zoo electrodes muaj teeb meem kev nyab xeeb loj. Tsis tas li ntawd, oxidation/crosstalk ntawm lwm yam roj teeb, xws li cov organic kua thiab tsis zoo electrodes, kuj tuaj yeem ua rau thermal runaway, uas yog suav tias yog qhov ua rau muaj teeb meem kev nyab xeeb. Lub hauv-situ controllable tsim ntawm ruaj khov electrode-electrolyte interface yog thawj lub tswv yim rau tiam tom ntej ntawm high-zog-density lithium-based roj teeb. Tshwj xeeb, cov khoom thiab ntom cathode-electrolyte interphase (CEI) nrog ntau dua thermal stability inorganic Cheebtsam tuaj yeem daws qhov teeb meem kev nyab xeeb los ntawm inhibiting tso pa tawm. Txog tam sim no, tsis muaj kev tshawb fawb txog CEI cathode-hloov cov ntaub ntawv thiab roj teeb-theem kev nyab xeeb.

Achievement zaub

Tsis ntev los no, Feng Xuning, Wang Li, thiab Ouyang Minggao ntawm Tsinghua University tau luam tawm cov ntaub ntawv tshawb fawb hu ua "In-Ultraconformal Interphases Enable High-Safety Practical Lithium Batterys" ntawm Cov Khoom Siv Hluav Taws Xob. Tus sau tau soj ntsuam kev nyab xeeb kev ua tau zoo ntawm cov tswv yim NMC811 / Gr mos-packed tag nrho roj teeb thiab thermal stability ntawm CEI zoo electrode. Lub thermal runaway suppression mechanism ntawm cov khoom siv thiab cov roj teeb muag muag tau kawm tiav. Siv lub tshuab hluav taws xob tsis zoo perfluorinated electrolyte, NMC811 / Gr hnab-hom roj teeb puv tau npaj. Lub thermal stability ntawm NMC811 tau txhim kho los ntawm in-site tsim CEI tiv thaiv txheej nplua nuj nyob rau hauv inorganic LiF. CEI ntawm LiF tuaj yeem txo cov pa oxygen tso tawm los ntawm cov theem hloov thiab inhibit qhov exothermic cov tshuaj tiv thaiv ntawm NMC811 zoo siab thiab fluorinated electrolyte.

Daim duab qhia

Daim duab 1 Kev sib piv ntawm thermal runaway yam ntxwv ntawm cov tswv yim NMC811/Gr hnab-hom roj teeb puv siv perfluorinated electrolyte thiab cov pa electrolyte. Tom qab ib lub voj voog ntawm ib txwm siv (a) EC / EMC thiab (b) perfluorinated FEC / FEMC / HFE electrolyte hnab hom roj teeb puv. (c) Pa EC / EMC electrolysis thiab (d) perfluorinated FEC / FEMC / HFE electrolyte hnab-hom roj teeb puv hnub nyoog tom qab 100 cycles.

Rau NMC811 / Gr roj teeb nrog ib txwm electrolyte tom qab ib lub voj voog (Daim duab 1a), T2 yog ntawm 202.5 ° C. T2 tshwm sim thaum qhov qhib-circuit voltage poob. Txawm li cas los xij, T2 ntawm lub roj teeb uas siv cov perfluorinated electrolyte nce mus txog 220.2 ° C (Daim duab 1b), uas qhia tau hais tias perfluorinated electrolyte tuaj yeem txhim kho qhov kev nyab xeeb ntawm lub roj teeb rau qee yam vim nws cov thermal stability ntau dua. Raws li lub hnub nyoog roj teeb, T2 tus nqi ntawm cov tsoos electrolyte roj teeb poob rau 195.2 ° C (Daim duab 1c). Txawm li cas los xij, cov txheej txheem kev laus tsis cuam tshuam rau T2 ntawm lub roj teeb uas siv perfluorinated electrolytes (Daim duab 1d). Tsis tas li ntawd, qhov siab tshaj plaws dT / dt tus nqi ntawm lub roj teeb uas siv cov tshuaj electrolyte thaum lub sij hawm TR yog siab li 113 ° C s-1, thaum lub roj teeb uas siv cov perfluorinated electrolyte tsuas yog 32 ° C s-1. Qhov sib txawv ntawm T2 ntawm cov roj teeb uas muaj hnub nyoog tuaj yeem raug ntaus nqi los ntawm cov khoom siv thermal stability ntawm zoo siab NMC811, uas yog txo qis hauv cov pa electrolytes, tab sis tuaj yeem tswj tau zoo nyob rau hauv perfluorinated electrolytes.

Daim duab 2 Thermal stability ntawm delithiation NMC811 zoo electrode thiab NMC811/Gr roj teeb sib tov. (A,b) Contour maps ntawm C-NMC811 thiab F-NMC811 synchrotron high-energy XRD thiab qhov sib thooj (003) diffraction ncov hloov. (c) Cov cua kub thiab oxygen tso tus cwj pwm ntawm qhov zoo electrode ntawm C-NMC811 thiab F-NMC811. (d) DSC nkhaus ntawm cov qauv sib xyaw ntawm qhov zoo siab electrode, lithiated tsis zoo electrode, thiab electrolyte.

Cov duab 2a thiab b qhia HEXRD nkhaus ntawm zoo siab NMC81 nrog sib txawv CEI khaubncaws sab nraud povtseg nyob rau hauv lub xub ntiag ntawm pa electrolytes thiab lub sij hawm ntawm chav tsev kub mus rau 600 ° C. Cov txiaj ntsig tau pom meej meej tias nyob rau hauv lub xub ntiag ntawm ib qho electrolyte, muaj zog CEI txheej yog qhov zoo rau thermal stability ntawm lithium-deposited cathode. Raws li pom nyob rau hauv daim duab 2c, ib qho F-NMC811 tau pom qhov qis qis qis qis ntawm 233.8 ° C, thaum lub ncov C-NMC811 exothermic tshwm sim ntawm 227.3 ° C. Tsis tas li ntawd, qhov kev siv thiab tus nqi ntawm cov pa oxygen tso tawm los ntawm cov theem hloov ntawm C-NMC811 yog qhov hnyav dua li cov F-NMC811, ntxiv kev lees paub tias CEI muaj zog txhim kho qhov muaj peev xwm thermal stability ntawm F-NMC811. Daim duab 2d ua ib qho kev xeem DSC ntawm kev sib xyaw ntawm kev zoo siab NMC811 thiab lwm yam khoom siv roj teeb. Rau cov pa electrolytes, cov exothermic peaks ntawm cov qauv nrog 1 thiab 100 cycles qhia tias kev laus ntawm cov tsoos interface yuav txo thermal stability. Nyob rau hauv sib piv, rau cov perfluorinated electrolyte, cov duab qhia tom qab 1 thiab 100 cycles qhia broad thiab me ntsis exothermic peaks, nyob rau hauv txoj kab nrog TR trigger kub (T2). Cov txiaj ntsig (Daim duab 1) zoo ib yam, qhia tias CEI muaj zog tuaj yeem txhim kho thermal stability ntawm cov laus thiab zoo siab NMC811 thiab lwm yam roj teeb.

Daim duab 3 Tus cwj pwm ntawm kev zoo siab NMC811 zoo electrode nyob rau hauv perfluorinated electrolyte. (ab) Hla-sectional SEM dluab ntawm cov laus F-NMC811 zoo electrode thiab coj EDS mapping. (ch) Element distribution. (ij) Hla-sectional SEM duab ntawm lub hnub nyoog F-NMC811 zoo electrode ntawm virtual xy. (km) Reconstruction of 3D FIB-SEM structure and spatial distribution of F elements.

Txhawm rau kom paub meej txog kev tsim cov tshuaj fluorinated CEI, cov kab mob sib kis thiab cov khoom faib tawm ntawm cov hnub nyoog NMC811 zoo electrode zoo tu qab tso rau hauv lub pob hluav taws xob tiag tiag yog tus cwj pwm los ntawm FIB-SEM (Daim duab 3 ah). Hauv perfluorinated electrolyte, ib txheej fluorinated CEI txheej yog tsim nyob rau saum npoo ntawm F-NMC811. Ntawm qhov tsis sib xws, C-NMC811 hauv cov pa electrolyte tsis muaj F thiab tsim cov txheej txheem CEI tsis sib xws. Cov ntsiab lus F nyob rau ntawm ntu ntu ntawm F-NMC811 (Daim duab 3h) yog siab dua li ntawm C-NMC811, uas ntxiv ua pov thawj tias qhov tsim ntawm inorganic fluorinated mesophase yog tus yuam sij rau kev tswj xyuas qhov ruaj khov ntawm kev zoo siab NMC811. . Nrog kev pab los ntawm FIB-SEM thiab EDS daim ntawv qhia, raws li qhia hauv daim duab 3m, nws tau pom ntau lub ntsiab lus F hauv 3D qauv ntawm qhov chaw ntawm F-NMC811.

Daim duab 4a) Element tob tis rau saum npoo ntawm tus thawj thiab zoo siab NMC811 zoo electrode. (ac) FIB-TOF-SIMS yog sputtering kev faib ntawm F, O, thiab Li cov ntsiab lus nyob rau hauv zoo electrode ntawm NMC811. (df) Qhov saum npoo morphology thiab qhov tob faib ntawm F, O, thiab Li ntsiab ntawm NMC811.

FIB-TOF-SEM qhia ntxiv qhov tob ntawm cov khoom ntawm qhov chaw ntawm qhov zoo electrode ntawm NMC811 (Daim duab 4). Piv nrog rau cov qauv qub thiab C-NMC811, qhov kev nce ntxiv hauv F teeb liab tau pom nyob rau saum npoo ntawm F-NMC811 (Daim duab 4a). Tsis tas li ntawd, qhov tsis muaj zog O thiab siab Li cov cim ntawm qhov chaw qhia txog kev tsim ntawm F- thiab Li-nplua nuj CEI txheej (Daim duab 4b, c). Cov txiaj ntsig no tau lees paub tias F-NMC811 muaj LiF-nplua nuj CEI txheej. Piv nrog rau CEI ntawm C-NMC811, CEI txheej ntawm F-NMC811 muaj ntau F thiab Li ntsiab. Tsis tas li ntawd, raws li qhia hauv FIGS. 4d-f, los ntawm qhov kev xav ntawm ion etching qhov tob, tus qauv ntawm tus thawj NMC811 yog qhov muaj zog dua li qhov zoo siab NMC811. Qhov tob tob ntawm cov hnub nyoog F-NMC811 yog me dua C-NMC811, uas txhais tau hais tias F-NMC811 muaj kev ruaj ntseg zoo heev.

Daim duab 5 CEI tshuaj muaj pes tsawg leeg nyob rau saum npoo ntawm qhov zoo electrode ntawm NMC811. (a) XPS spectrum ntawm NMC811 zoo electrode CEI. (bc) XPS C1s thiab F1s spectra ntawm thawj thiab zoo siab NMC811 zoo electrode CEI. (d) Cryo-transmission electron microscope: element tis ntawm F-NMC811. (e) Frozen TEM duab ntawm CEI tsim ntawm F-NMC81. (fg) STEM-HAADF thiab STEM-ABF cov duab ntawm C-NMC811. (nyob zoo) STEM-HAADF thiab STEM-ABF cov duab ntawm F-NMC811.

Lawv siv XPS los qhia cov tshuaj muaj pes tsawg leeg ntawm CEI hauv NMC811 (Daim duab 5). Tsis zoo li tus thawj C-NMC811, CEI ntawm F-NMC811 muaj F thiab Li loj tab sis me C (Daim duab 5a). Kev txo qis ntawm C hom qhia tias LiF-nplua nuj CEI tuaj yeem tiv thaiv F-NMC811 los ntawm kev txo cov kev cuam tshuam sab nraud nrog electrolytes (Daim duab 5b). Tsis tas li ntawd, cov nqi me me ntawm CO thiab C = O qhia tias kev daws teeb meem ntawm F-NMC811 tsuas yog txwv. Hauv F1s spectrum ntawm XPS (Daim duab 5c), F-NMC811 tau pom lub teeb liab LiF muaj zog, lees tias CEI muaj ntau LiF tau los ntawm cov kuab tshuaj fluorinated. Daim duab qhia ntawm F, O, Ni, Co, thiab Mn cov ntsiab lus hauv cheeb tsam hauv cheeb tsam ntawm F-NMC811 cov khoom qhia tau hais tias cov ntsiab lus tau muab faib ua ib feem (Daim duab 5d). Daim duab TEM kub qis hauv daim duab 5e qhia tau hais tias CEI tuaj yeem ua raws li cov txheej txheem tiv thaiv kom sib npaug ntawm NMC811 zoo electrode. Txhawm rau kom paub meej ntxiv txog cov qauv kev hloov pauv ntawm qhov sib txuas, lub kaum sab xis ntawm qhov tsaus ntuj-teb scanning kis tau tus mob electron microscopy (HAADF-STEM thiab lub voj voog ci ntsa iab scanning kis tau tus mob electron microscopy (ABF-STEM) thwmsim) tau ua. -NMC811), Qhov saum npoo ntawm cov hluav taws xob zoo electrode tau dhau los ua ib qho kev hloov pauv loj heev, thiab cov theem tsis zoo ntawm pob zeb ntsev yog khaws cia rau saum npoo ntawm qhov zoo electrode (Daim duab 5f). Qhov zoo electrode tswj cov txheej txheem txheej (Daim duab 811h), qhia tias muaj teeb meem Cov theem yuav ua tau zoo suppressed. Tsis tas li ntawd, cov txheej txheem CEI tau pom nyob rau saum npoo ntawm F-NMC5 (Daim duab 811i-g). CEI txheej ntawm qhov zoo electrode nto ntawm NMC5 hauv perfluorinated electrolyte.

Daim duab 6a) TOF-SIMS spectrum ntawm theem interphase ntawm qhov chaw ntawm NMC811 zoo electrode. (ac) Kev tsom xam qhov tob ntawm qhov tshwj xeeb thib ob ion fragments ntawm qhov zoo electrode ntawm NMC811. (df) TOF-SIMS tshuaj spectrum ntawm qhov thib ob ion fragment tom qab 180 vib nas this ntawm sputtering ntawm tus thawj, C-NMC811 thiab F-NMC811.

C2F-fragments feem ntau suav hais tias yog cov organic tshuaj ntawm CEI, thiab LiF2- thiab PO2-fragments feem ntau suav hais tias yog hom kab mob. Kev txhim kho tseem ceeb ntawm LiF2- thiab PO2- tau txais hauv qhov kev sim (Daim duab 6a, b), qhia tias CEI txheej ntawm F-NMC811 muaj ntau hom inorganic. Ntawm qhov tsis sib xws, C2F-cim ntawm F-NMC811 tsis muaj zog dua li ntawm C-NMC811 (Daim duab 6c), uas txhais tau hais tias CEI txheej ntawm F-NMC811 muaj cov kab mob tsis yooj yim dua. Kev tshawb fawb ntxiv pom (Daim duab 6d-f) tias muaj ntau hom inorganic hauv CEI ntawm F-NMC811, thaum muaj tsawg hom inorganic hauv C-NMC811. Tag nrho cov txiaj ntsig no qhia txog kev tsim cov khoom tsis muaj zog-nplua nuj CEI txheej hauv perfluorinated electrolyte. Piv nrog rau NMC811 / Gr cov roj teeb muag muag uas siv cov khoom siv hluav taws xob ib txwm muaj, kev txhim kho kev nyab xeeb ntawm cov roj teeb mos uas siv perfluorinated electrolyte tuaj yeem raug ntaus nqi rau: Ua ntej, qhov tsim ntawm CEI txheej nplua nuj nyob hauv inorganic LiF yog qhov zoo. Lub hauv paus thermal stability ntawm zoo siab NMC811 zoo electrode txo qhov tso tawm ntawm lattice oxygen tshwm sim los ntawm kev hloov theem; Thib ob, cov khoom tsis zoo hauv CEI tiv thaiv txheej ntxiv tiv thaiv qhov ua rau muaj kev cuam tshuam ntau heev NMC811 los ntawm kev tiv tauj cov electrolyte, txo cov exothermic sab cov tshuaj tiv thaiv; thib peb, Cov perfluorinated electrolyte muaj thermal stability ntawm qhov kub thiab txias.

Xaus thiab Outlook

Cov hauj lwm no tau tshaj tawm txog kev txhim kho cov tswv yim Gr/NMC811 hnab-hom roj teeb uas siv cov perfluorinated electrolyte, uas ua rau nws zoo dua nws txoj kev nyab xeeb. Intrinsic thermal stability. Ib qho kev kawm tob ntawm TR inhibition mechanism thiab kev sib raug zoo ntawm cov ntaub ntawv thiab roj teeb. Cov txheej txheem kev laus tsis cuam tshuam rau TR qhov ntsuas kub (T2) ntawm lub roj teeb perfluorinated electrolyte thaum lub caij cua daj cua dub tag nrho, uas muaj qhov zoo ntawm cov roj teeb uas siv cov khoom siv hluav taws xob. Tsis tas li ntawd, lub ncov exothermic yog ua raws li cov txiaj ntsig ntawm TR, qhia tias qhov muaj zog CEI yog qhov tsim nyog rau thermal stability ntawm lithium-dawb zoo electrode thiab lwm yam roj teeb. Cov txiaj ntsig no qhia tau hais tias kev tswj hwm hauv qhov chaw tsim kho ntawm cov txheej txheem CEI ruaj khov muaj cov lus qhia tseem ceeb rau kev siv cov roj teeb lithium roj teeb uas muaj kev nyab xeeb dua.

Cov ntaub ntawv keeb kwm

Nyob rau hauv-Ua Ultraconformal Interphases Ua kom muaj kev nyab xeeb siab siv lithium roj teeb, cov khoom siv hluav taws xob, 2021.