MOF / Poly (Ethylene Oxide) Composite Polymer Electrolyte rau Solid-state Lithium Battery
LIANG Fengqing, WEN Zhaoyin
1. CAS tseem ceeb Laboratory ntawm cov ntaub ntawv rau lub zog hloov, Shanghai lub koom haum ntawm Ceramics, Suav Academy ntawm Sciences, Shanghai 200050, Tuam Tshoj
2. Center of Materials Science thiab Optoelectronics Engineering, University of Suav Academy ntawm Sciences, Beijing 100049, Suav
Abstract
Cov khoom siv polymer electrolytes (SPEs) nrog kev hloov pauv tau yooj yim thiab kev ua tau zoo pab kom tsim cov roj teeb uas tsis muaj hluav taws xob hauv lub xeev nrog ntau yam geometries. Txawm li cas los xij, SPEs feem ntau raug kev txom nyem los ntawm qhov tsis tshua muaj ionic conductivity thiab kev ruaj ntseg tsis zoo nrog lithium hlau anodes. Ntawm no, peb tawm tswv yim nano-sized hlau-organic moj khaum (MOF) khoom (UiO-66) raws li muab tub lim rau poly (ethylene oxide) (PEO) polymer electrolyte. Kev sib koom ua ke ntawm UiO-66 nrog cov pa oxygen hauv PEO saw thiab kev sib cuam tshuam ntawm UiO-66 thiab lithium ntsev txhim kho cov ionic conductivity (3.0×10 -5 S/cm ntawm 25 degree , 5.8 × 10 -4 S/cm ntawm 60 degree ntawm Li 1 ) thiab hloov pauv ({ence electron) ntawm 2. .9 V (vs Li ntxiv / Li), txhim khu kev ruaj ntseg nrog lithium hlau anode. Raws li qhov tshwm sim, cov li npaj Li symmetrical hlwb tuaj yeem ua haujlwm tsis tu ncua rau 1000 h ntawm 0.15 mA∙cm -2, 60 degree . Cov txiaj ntsig tau pom tias UiO-66 muab tub lim muaj txiaj ntsig los txhim kho kev ua haujlwm ntawm electrochemical ntawm polymer electrolyte.
Ntsiab lus:electrolyte sib xyaw; poly (ethylene oxide); cov khoom siv hlau-organic; lithium hlau roj teeb
Lithium-batteries thev naus laus zis tuaj yeem txhim kho los ntawm kev hloov cov kua electrolytes tam sim no siv nrog cov khoom siv polymer electrolytes (SPEs), ua kom cov ntaub ntawv hloov tau yooj yim, compact, laminated solid-state structures dawb los ntawm kev xau thiab muaj nyob rau hauv ntau yam geometries. Cov SPEs tshawb nrhiav rau cov hom phiaj no yog ionically ua cov ntaub ntawv polymer uas tsim los ntawm cov complexes ntawm lithium ntsev (LiX) thiab siab molecular hnyav polymer uas muaj Li ntxiv rau kev koom tes pab pawg, xws li poly (ethylene oxide) (PEO). Nyob rau hauv PEO polymer electrolytes, nrog rau cov polymer nyob rau hauv amorphous xeev, Li ntxiv yog ceev thauj nrog rau lub zos so thiab segmental segmental motion ntawm polymer saw, tab sis lub PEO nyhav crystallize hauv qab no 6 {{10}} degree . Yog li cov conductivity ntawm PEO polymer electrolytes ncav cuag qhov muaj txiaj ntsig zoo (ntawm qhov kev txiav txim ntawm 10-4 S / cm) tsuas yog ntawm qhov kub siab tshaj 6 {{20}} degree . Ntau qhov kev sim ua kom txo qis cov polymer crystallinity tau tsim los txhim kho cov conductivity ntawm cov polymer electrolytes, nrog rau kev sib xyaw nrog lwm cov co-polymers, ntxiv plasticizers thiab doping inorganic hais. Inorganic cov ntaub ntawv inorganic rau hauv polymer matrix yog txoj kev vam meej tshaj plaws, uas txhim kho ionic conductivity nrog rau electrochemical stability thiab mechanical zog. Cov ntaub ntawv inorganic no feem ntau suav nrog cov khoom siv tsis zoo, xws li SSZ-13, Al2O3, SiO2, thiab cov khoom siv hluav taws xob, xws li Li0.33La0.57TiO3, Li6.75La3Zr1.75Ta0.25O12, thiab Li1.5Al0.5Ge1.5(PO4)3. Kev tshawb fawb pom tau tias nanoparticles nrog Lewis acidic nto zog tuaj yeem ua kom muaj txiaj ntsig zoo ntawm kev sib cais ntawm lithium ntsev thiab txo cov crystallinity ntawm PEO, yog li txhim kho cov ionic conductivity. Txawm li cas los xij, kev sib cuag tsis zoo ntawm inorganic nanoparticle thiab PEO rau qhov sib txawv ntawm lub zog saum npoo feem ntau ua rau tsis sib haum xeeb. Ceramic fillers grafted nrog molecular txhuam thiab hloov nrog dopamine yog endowed nrog inorganic-organic zog. Lawv cia siab tias yuav txhim kho cov miscibility nrog PEO, yav tom ntej txhim kho cov ionic conductivity thiab stability ntawm polymer electrolytes.
Hlau-organic moj khaum (MOFs) uas muaj cov hlau ion pawg thiab cov organic linkers yog cov khoom siv nanoporous, uas muaj cov cuab yeej inorganic-organic hybrid thiab siab tshwj xeeb ntawm thaj chaw, yog li ua qhov zoo tagnrho rau cov khoom siv hluav taws xob polymer. Nyob rau hauv 2013, Yuan, et al. siv Zn4O(1,4-benzenedicarboxylate)3 hlau-organic moj khaum (MOF-5) ua muab tub lim rau PEO electrolyte tau siab ionic conductivity ntawm 3.16 × 10-5 S∙cm-1 (25 degree) vim muaj kev sib cais tsis sib xws. Tab sis cov hlau tsis muaj zog-organic kev sib koom ua ke ntawm MOF-5 yooj yim raug tawm tsam, ua rau kev hloov pauv siv lead ua lossis cov qauv tawg thiab tsis zoo rau cov roj teeb lithium.
Hauv kev ua haujlwm no, nano-loj UiO-66, ib qho ntawm cov kev tshawb nrhiav dav dav MOFs, tau qhia ua tus muab tub lim rau hauv PEO electrolyte. UiO-66 nrog rau qhov zoo ntawm hydrothermal thiab tshuaj stability tsis muaj cov hlau hloov pauv uas muab cov chaw redox-active, yog li cov hluav taws xob conduction tuaj yeem zam tau thaum sib cuag nrog hlau Li.
1 Kev sim
1.1 Synthesis of nano-loj UiO-66
Nano-loj UiO-66 tau ua ke raws li kev tshaj tawm ob-kauj ruam synthesis. (1) 207 mg ZrCl4 (98 feem pua, Aladdin) tau yaj hauv 40 mL N, N-dimethylformamide (DMF) (99.9 feem pua, Aladdin) nyob rau hauv nplawm, thiab cov tshuaj tau rhuab mus txog 120 degree rau 2 h. Tom qab ntawd 1 mL acetic acid ntxiv thiab nplawm rau ntxiv 0.5 h ntawm 120 degree. (2) 147 mg 1,4-benzenedicarboxylic acid (H2BDC) (99 feem pua, Aladdin) tau ntxiv rau hauv cov tshuaj. Thiab cov txiaj ntsig sib xyaw tau nkag mus rau hauv 50 mL Teflon-lined stainless-steel autoclave thiab muab tso rau hauv qhov cub ntawm 120 degree rau 24 teev. Tom qab txias rau hauv chav tsev kub, lub resulting precipitates tau centrifuged, ntxuav nrog DMF, purified nyob rau hauv methanol thiab ces qhuav ntawm 60 degree nyob rau hauv lub nqus tsev vacuum rau 24 teev.
1.2 Kev npaj ntawm UiO-66/PEO puas polymer electrolytes (CPEs)
PEO (Mw {{0}}} ~ 600, 000, 99.9 feem pua, Aladdin) tau qhuav ntawm 50 degree, thiab lithium bis (trifluoromethanesulfonyl) imide (LiTFSI) (99 feem pua, Aladdin) tau qhuav ntawm 100 degree rau 24 teev. Ua ntej, LiTFSI tau yaj nyob rau hauv anhydrous acetonitrile, thiab UiO-66 thiab PEO tau ntxiv nyob rau hauv sib nqus nplawm kom them nyiaj homogeneous tov, nyob rau hauv uas molar ratio ntawm EO: Li ntxiv tau khaws cia 16 : 1, thiab cov ntsiab lus ntawm nano-loj UiO -66 0, 2 feem pua ntawm cov fillers, 10% , 25 feem pua, naming cov electrolytes coj li SPE, CPE-(5 feem pua, 10 feem pua, 15 feem pua, 20 feem pua, 25 feem pua). Tom qab ntawd, cov tshuaj tau muab pov rau ntawm polytetrafluoroethylene template kom volatilize cov kuab tshuaj ntawm ambient kub. Thaum kawg, cov daim nyias nyias tau qhuav ntawm 60 degree rau 12 teev nyob rau hauv lub tshuab nqus tsev kom volatilize cov residual hnyav.
1.3 Kev ua piv txwv
Cov qauv crystalline ntawm cov khoom xyaw tau sau los ntawm X-ray diffraction (XRD) nrog Cu-K hluav taws xob (λ=0.1542 nm) ntawm chav tsev kub (2θ=5 degree -50 degree) nrog rau qib ntawm 0.1 (degree)/s. Cov qauv morphologies ntawm UiO-66 thiab CPE tau tshwm sim los ntawm scanning electron microscopy (SEM, Hitachi, S-3400N).
1.4 Kev ntsuas hluav taws xob thiab cov hlwb sib dhos
Lub ionic conductivity yog ntsuas ntawm qhov kub ntawm 25 mus rau 80 degree hauv symmetric cell nrog stainless hlau (SS) electrodes los ntawm AC impedance tsom xam (Autolab, Model PGSTAT302N) nyob rau hauv lub zaus ntawm 1 Hz mus rau 1 MHz thiab ntawm ib tug amplitude ntawm 5 mV. Linear sweep voltammetry (LSV) tau ua haujlwm los tshuaj xyuas lub qhov rai electrochemical hauv SS/electrolyte/Li cells, ua los ntawm 3 txog 5.5 V ntawm tus nqi scan ntawm 10 mV/s. Tus lej hloov pauv ntawm Li plus (t plus) tau sim hauv Li / electrolyte / Li cell thiab xam raws li t plus {{10}} I∞( Δ V−I0R0)I0( Δ V−I∞R∞), qhov twg ΔV yog qhov siv DC polarization voltage (10 mV), I0 thiab I0 tam sim no tus nqi pib R0 thiab R∞ yog qhov tseem ceeb tiv thaiv ua ntej thiab tom qab polarization, feem. Rau inhibition muaj peev xwm ntawm lithium dendrites kev loj hlob test, ib tug symmetric cell nrog cov khoom electrolyte sandwiched ntawm ob lithium hlau electrode tau sib sau ua ke, thiab qhov kev ntsuam xyuas tau ua nyob rau ntawm 60 degree.
2 Cov txiaj ntsig thiab kev sib tham
UiO{{0}} ([Zr6O4(OH)4(BDC)6], qhov twg BDC2- yog 1,4- benzenedicarboxylic acid radical) nrog lub ntsej muag-centered cubic (fcc) lattice qauv (Fig. 1(a)) muaj xws li cov BH) 1 octhocytes (B. edral thiab 0.75nm tetrahedral tawb. Fig. 1(b) yog SEM duab ntawm raws li npaj UiO{19}} qhov twg cov muaju yog kheej kheej nrog 80-150 nm loj. UiO-66 tau muab tso rau hauv PEO-LiTFSI polymer electrolyte los tsim cov khoom siv hluav taws xob los ntawm txoj kev daws teeb meem yooj yim. Ib tug du nto ntawm composite electrolyte yog pom nyob rau hauv daim duab 1(c), qhia tau hais tias cov nano-sized UiO-66 fillers yog uniformly faib nyob rau hauv PEO matrix vim lub inorganic-organic hybrid khoom ntawm UiO{28}}.
Fig. 1 (a) Cov qauv siv lead ua ntawm UiO-66, thiab SEM cov duab ntawm (b) nano-sized UiO-66 thiab (c) UiO-66/PEO composite polymer electrolyte
Cov theem purity ntawm raws li-npaj UiO-66 cov crystals tau lees paub los ntawm XRD qauv uas zoo sib xws nrog cov simulated ib qho raws li cov ntaub ntawv qhia cov ntaub ntawv, raws li qhia hauv daim duab 2(a), qhia txog kev ua tiav ntawm nanostructure ntawm UiO-66. Cov ntsiab lus ntawm UiO-66 nyob rau hauv polymer electrolyte tau optimized kom ua tau siab ionic conductivity. Arrhenius plots rau PEO electrolytes nrog sib txawv UiO-66 cov ntsiab lus tau qhia hauv daim duab 2(b).
Fig. 2 (a) XRD qauv ntawm simulated UiO-66, synthesized nano-sized UiO-66, PEO, thiab CPE-10 feem pua ; (b) Arrhenius cov phiaj xwm rau ionic conductivities ntawm PEO electrolytes nrog cov ntsiab lus sib txawv ntawm UiO-66; (c) Nyqiust plots nyob rau hauv zaus ntawm 1 Hz -1 MHz rau CPE -10 feem pua ntawm qhov kub ntawm 25 mus rau 80 degree ; (d) LSV nkhaus ntawm SPE thiab CPE hauv SS/electrolyte/Li hlwb ntawm 60 degree; (e) DC polarization profile ntawm symmetric Li / SPE / Li cell ntawm qhov siv hluav taws xob ntawm 10 mV ntawm 60 degree; (f) DC polarization profile ntawm symmetric Li/CPE-10 feem pua /Li cell ntawm qhov siv hluav taws xob ntawm 10 mV ntawm 60 degree . Insets nyob rau hauv (e,f): AC impedance spectra ntawm cov symmetric cells ua ntej thiab tom qab DC polarization
Nws yog qhov tseeb tias cov ionic conductivity ntau dua tau txais nrog qhov sib ntxiv ntawm nano-loj UiO-66 rau hauv PEO electrolyte. Raws li kev sib koom tes ntawm [Zr6O4(OH)4]12 ntxiv nrog oxygen hauv PEO txo cov crystallinity ntawm PEO saw los txhawb cov segmental motion ntawm polymer saw, uas yog pov thawj los ntawm XRD qauv ntawm CPE-10 feem pua piv nrog PEO (Fig. 2(a)). Ntxiv mus, kev sib cuam tshuam ntawm [Zr6O4(OH)4]12 ntxiv thiab TFSI- txhawb kev sib cais ntawm lithium ntsev. Qhov nce ntawm UiO-66 fillers cov ntsiab lus hauv qab ib qho nqi yog nrog los ntawm kev txhawb nqa ntawm ionic conductivity. Txawm li cas los xij, kev nce ntxiv ntawm cov fillers txo cov ionic conductivity vim yog dilution thiab thaiv cov teebmeem. CPE -10}} ionic conductivity (3} {{{{{ 29}} S / cm ntawm 60 degree. Cov khoom ua haujlwm ntawm CPE-10 feem pua ntawm qhov kub ntawm 25 txog 80 degree kuj tau tshawb xyuas los ntawm AC impedance spectroscopy, thiab Nyqiust cov phiaj xwm tau nthuav tawm hauv daim duab 2(c). Nws qhia tau hais tias tus nqi impedance txo nrog qhov kub thiab txias.
Cov nyhuv ntawm UiO{{0}} ntawm lub qhov rais electrochemical ntawm PEO electrolyte tau tshawb xyuas los ntawm LSV ntawm 60 degree . Raws li tau pom hauv daim duab 2(d), lub platform ruaj khov ntawm CPE-10 feem pua ntawm 4.9 V yog siab dua li ntawm SPE, vim yog kev sib koom ua ke ntawm UiO-66 nrog oxygen uas txhawb nqa oxidation voltage ntawm PEO thiab qhov tseeb tias Zr(IV) hauv UiO-66 yog qhov nyuaj kom txo tau. Yog li, nws xav tias CPE yog qhov tsim nyog rau lub roj teeb lithium sib piv nrog high-voltage zoo cathode. Tus lej hloov pauv ntawm Li ntxiv yog qhov tseem ceeb uas muab cov ntaub ntawv hais txog tus nqi muaj peev xwm ntawm Li ntxiv rau hauv cov khoom hauv lub xeev electrolyte. Lub sij hawm-tam sim no nkhaus tom qab 10 mV ntawm DC polarization rau SPE thiab CPE-10 feem pua yog nthuav tawm hauv daim duab 2(ef). Qhov t ntxiv ntawm CPE-10 feem pua yog 0.36 thiab siab dua li ntawm SPE (0.25). Nws yog vim qhov tseeb tias kev sib koom tes ntawm [Zr6O4 (OH) 4] 12 ntxiv nrog cov pa oxygen ntawm PEO hauv CPEs tsis muaj zog rau kev sib koom tes ntawm oxygen nrog Li ntxiv rau kev hloov pauv ntawm Li ntxiv, thiab ib feem ntawm cov anions yog immobilized los ntawm [Zr6O4(OH)4] 12 ntxiv .
Lub sij hawm ntev electrochemical stability tiv thaiv lithium anode yog ib qho tseem ceeb feature ntawm solid-state electrolyte, uas yuav ntsuas los ntawm galvanostatic lithium plating thiab striping nyob rau hauv symmetric Li / electrolyte / Li hlwb. Fig. 3(a) qhia lub qhov rais voltage nrog qhov ceev tam sim no ntawm 0.15 mA∙cm-2 rau 1 h txhua lub voj voog ntawm 60 degree . Hauv daim duab 3(b), qhov sib luag Li/CPE-10 feem pua /Li cell qhia txog kev them nqi hluav taws xob ntau ntawm -0.058 thiab 0.06 V hauv thawj lub voj voog thiab tom qab ntawd txo qis me ntsis rau -0.048-0.053 V tom qab 900 cycles electroth PE thiab CPE zoo heev, qhia txog kev ruaj ntseg ntawm cov hlau thiab CPE. Dendrite kev loj hlob. Qhov peev xwm no tuaj yeem ua raws li cov hauv qab no: (1) txhim kho txhua yam zog; (2) ib feem ntawm cov anions immobilized los ntawm [Zr6O4(OH)4] 12 ntxiv rau boosting lub uniform Li plating thiab striping. Nyob rau hauv sib piv, lub charge-discharge voltage ntawm symmetric Li/SPE/Li cell ranges ntawm -0.25 mus rau 0.37 V nyob rau hauv thawj lub voj voog (Fig. 3(b)), thiab lub roj teeb qhia luv luv Circuit Court tom qab 104 h. Qhov kev ua haujlwm tsis zoo li no tuaj yeem raug liam rau qhov tsis sib xws Li plating thiab striping, uas tshwm sim los ntawm qhov qis t ntxiv ntawm SPE muaj ntau cov anions dawb.
Fig. 3 (a) Galvanostatic cycles nrog qhov ceev tam sim no ntawm 0.15 mA∙cm-2 rau symmetric Li/CPE-10 feem pua /Li thiab Li/SPE/Li hlwb ntawm 60 degree , (b) magnification ntawm galvanostatic cycles ntawm Li/CPE {6}% thiab{{Li/CPE} thiab{ (c) magnification ntawm galvanostatic cycles ntawm Li/CPE-10 feem pua /Li cell ntawm 895-900 voj voog
3 Kev xaus
Hauv cov ntsiab lus, PEO-raws li electrolyte nrog UiO-66 raws li muab tub lim tau tsim los ntawm cov txheej txheem kev daws teeb meem. Raws li tau txais CPE-10 feem pua pom qhia siab ionic conductivities ntawm 3.0 ×10-5 S / cm ntawm 25 degree thiab 5.8 ×10-4 S / cm ntawm 60 degree , uas yog ntaus nqi rau cov nram qab no yam: (1) lub low crystallinity ntawm PEO 4O4 PE owing rau lub crystallinity ntawm PEO4 12 O saw; (2) kev sib cuam tshuam ntawm TFSI- thiab [Zr6O4(OH)4] 12 ntxiv rau kev txhawb nqa kev sib cais ntawm lithium ntsev. Tus lej hloov pauv siab dua ntawm Li ntxiv (0.36) yog vim qhov tsis tuaj yeem ntawm ib feem ntawm anion uas tseem muaj txiaj ntsig zoo rau kev muaj peev xwm txo qis lithium dendrite kev loj hlob ntawm CPE. Kev txhim kho txhua yam muaj zog thiab zoo heev electrochemical stability ntawm CPE tiv thaiv lithium hlau endow cov kev tiv thaiv zoo ntawm lithium dendrite kev loj hlob, ua rau lub neej ntev rau lithium hlau roj teeb (tshaj 1000 h cycling ntawm 0.15 mA∙cm{29}}, 60 degree ).
Ntau Lithium ion roj teeb cov ntaub ntawv los ntawmTOB New Energy
