ESM: Mawonekedwe opangidwa ndi ma electrolyte a perfluorinated pamabatire a lithiamu amphamvu kwambiri

Mbiri Yofufuza

Mu mabatire a lithiamu-ion, kuti akwaniritse cholinga cha 350 Wh Kg-1, zinthu za cathode zimagwiritsa ntchito nickel-rich layered oxide (LiNixMnyCozO2, x+y+z = 1, yotchedwa NMCxyz). Ndikuchulukirachulukira kwamphamvu, zowopsa zokhudzana ndi kuthawa kwa ma LIBs zakopa chidwi cha anthu. Kuchokera pamalingaliro azinthu, ma elekitirodi olemera a nickel ali ndi zovuta zazikulu zachitetezo. Kuphatikiza apo, ma oxidation / crosstalk ya zida zina za batri, monga zakumwa za organic ndi ma electrode olakwika, amathanso kuyambitsa kuthawa kwamafuta, komwe kumawerengedwa kuti ndizomwe zimayambitsa zovuta zachitetezo. Mapangidwe osinthika a in-situ a mawonekedwe okhazikika a electrode-electrolyte ndiyo njira yoyamba yam'badwo wotsatira wa mabatire a lithiamu-omwe ali ndi mphamvu zambiri. Mwachindunji, cholimba ndi wandiweyani cathode-electrolyte interphase (CEI) ndi apamwamba matenthedwe kukhazikika zigawo za inorganic angathe kuthetsa vuto la chitetezo poletsa kutuluka kwa mpweya. Pakadali pano, pali kusowa kwa kafukufuku pazinthu zosinthidwa za cathode za CEI komanso chitetezo cha batri.

Chiwonetsero chakuchita bwino

Posachedwapa, a Feng Xuning, Wang Li, ndi Ouyang Minggao a ku yunivesite ya Tsinghua adasindikiza pepala lofufuzira lotchedwa "In-Built Ultraconformal Interphases Enable High-Safety Practical Lithium Batteries" pa Zida Zosungira Mphamvu. Wolembayo adawunika momwe chitetezo cha batri yodzaza ndi NMC811/Gr yodzaza ndi kukhazikika kwamafuta ofananirako ndi ma elekitirodi a CEI. Thermal runaway kupondereza makina pakati pa zinthu ndi soft pack batire yaphunziridwa mozama. Pogwiritsa ntchito electrolyte yosayaka, batire lathunthu lamtundu wa NMC811/Gr linakonzedwa. Kukhazikika kwamafuta a NMC811 kudasinthidwa ndi in-situ yomwe idapangidwa ndi CEI yoteteza wosanjikiza wolemera mu LiF yachilengedwe. CEI ya LiF imatha kuchepetsa kutulutsa kwa okosijeni komwe kumachitika chifukwa cha kusintha kwa gawo ndikuletsa kuchitapo kanthu kwamphamvu pakati pa NMC811 yosangalatsa ndi electrolyte ya fluorinated.

Kalozera wazithunzi

Chithunzi 1 Kuyerekeza kwa mawonekedwe amtundu wa NMC811/Gr pouch-mtundu wa batri wathunthu pogwiritsa ntchito electrolyte perfluorinated electrolyte ndi electrolyte wamba. Pambuyo mkombero umodzi wa chikhalidwe (a) EC/EMC ndi (b) perfluorinated FEC/FEMC/HFE electrolyte thumba mtundu mabatire athunthu. (c) EC/EMC electrolysis wamba ndi (d) perfluorinated FEC/FEMC/HFE electrolyte pouch-mtundu batire lathunthu zaka pambuyo 100 mizungu.

Kwa batire ya NMC811/Gr yokhala ndi electrolyte yachikhalidwe pambuyo pa kuzungulira kumodzi (Chithunzi 1a), T2 ili pa 202.5°C. T2 imachitika pamene magetsi otseguka atsika. Komabe, T2 ya batire yogwiritsira ntchito electrolyte perfluorinated ikufika ku 220.2 ° C (Chithunzi 1b), zomwe zimasonyeza kuti electrolyte ya perfluorinated ikhoza kupititsa patsogolo chitetezo chamtundu wa batri kumlingo wina chifukwa cha kukhazikika kwake kwa kutentha. Pamene batire ikukalamba, mtengo wa T2 wa batire yachikhalidwe ya electrolyte umatsika kufika pa 195.2 °C (Chithunzi 1c). Komabe, kukalamba sikumakhudza T2 ya batri pogwiritsa ntchito electrolytes perfluorinated (Chithunzi 1d). Kuonjezera apo, mtengo wapamwamba wa dT/dt wa batire yogwiritsira ntchito electrolyte yachikhalidwe nthawi ya TR ndi yokwera kufika 113 ° C s-1, pamene batire yogwiritsira ntchito electrolyte perfluorinated ndi 32 ° C s-1 yokha. Kusiyana kwa T2 ya mabatire okalamba kungabwere chifukwa cha kukhazikika kwachilengedwe kwamafuta osangalatsa a NMC811, omwe amachepetsedwa pansi pa ma electrolyte wamba, koma amatha kusungidwa bwino pansi pa ma electrolyte a perfluorinated.

Chithunzi 2 Kukhazikika kwa kutentha kwa delithiation NMC811 electrode positive ndi NMC811/Gr batire losakaniza. (A,b) Mamapu ozungulira a C-NMC811 ndi F-NMC811 synchrotron yamphamvu kwambiri ya XRD ndi kusintha kofananirako (003) pachimake cha diffraction. (c) Kutentha ndi kutulutsa mpweya kwa ma elekitirodi abwino a C-NMC811 ndi F-NMC811. (d) DSC yokhotakhota yachitsanzo chosakanikirana cha electrode yabwino, lithiated negative electrode, ndi electrolyte.

Zithunzi 2a ndi b zikuwonetsa ma curve a HEXRD osangalatsa a NMC81 okhala ndi magawo osiyanasiyana a CEI pamaso pa ma electrolyte wamba komanso munthawi ya kutentha mpaka 600 ° C. Zotsatira zikuwonetseratu kuti pamaso pa electrolyte, chingwe cholimba cha CEI chimapangitsa kuti kutentha kwa cathode kusungidwe kwa lithiamu-deposited cathode. Monga momwe chithunzi 2c chikusonyezera, F-NMC811 imodzi inawonetsa pang'onopang'ono nsonga ya kutentha kwa 233.8 ° C, pamene C-NMC811 nsonga ya exothermic inawonekera pa 227.3 ° C. Kuphatikiza apo, mphamvu ndi kuchuluka kwa mpweya wotuluka chifukwa cha kusintha kwa gawo la C-NMC811 ndizowopsa kuposa za F-NMC811, kutsimikiziranso kuti mphamvu ya CEI imapangitsa kukhazikika kwamafuta a F-NMC811. Chithunzi 2d chimapanga mayeso a DSC pamitundu yosangalatsa ya NMC811 ndi zida zina zofananira za batri. Pakuti electrolytes ochiritsira, nsonga exothermic zitsanzo ndi 1 ndi 100 m'zinthu zimasonyeza kuti kukalamba mawonekedwe chikhalidwe kuchepetsa matenthedwe bata. Mosiyana ndi izi, ma electrolyte a perfluorinated, mafanizo pambuyo pa 1 ndi 100 akuwonetsa nsonga zazikuluzikulu ndi zofatsa, mogwirizana ndi kutentha kwa TR trigger (T2). Zotsatira (Chithunzi 1) ndizogwirizana, kusonyeza kuti CEI yolimba imatha kupititsa patsogolo kukhazikika kwa kutentha kwa okalamba ndi okondwa a NMC811 ndi zigawo zina za batri.

Chithunzi 3 Mawonekedwe a ma elekitirodi abwino a NMC811 mu perfluorinated electrolyte. (ab) Zithunzi za SEM zodutsamo za ma elekitirodi okalamba a F-NMC811 komanso mapu ogwirizana a EDS. (ch) Kugawa zinthu. (ij) Chithunzi cha SEM chodutsana ndi ma elekitirodi okalamba a F-NMC811 pa xy. (km) Kumanganso mawonekedwe a 3D FIB-SEM ndi kugawa kwapamalo kwa F element.

Kuti atsimikizire kutheka kupangidwa kwa fluorinated CEI, mawonekedwe amtundu wapakatikati ndi kugawa kwa ma elekitirodi okalamba a NMC811 omwe adapezeka mu batire yapaketi yofewa yeniyeni adadziwika ndi FIB-SEM (Chithunzi 3 ah). Mu electrolyte perfluorinated, yunifolomu fluorinated CEI wosanjikiza amapangidwa pamwamba F-NMC811. M'malo mwake, C-NMC811 mu electrolyte wamba ilibe F ndipo imapanga wosanjikiza wosagwirizana wa CEI. Zomwe zili patsamba la F-NMC811 (Chithunzi 3h) ndizokwera kuposa za C-NMC811, zomwe zimatsimikiziranso kuti mapangidwe a in-situ a mesophase ya inorganic fluorinated mesophase ndiye chinsinsi chothandizira kukhazikika kwa NMC811 yosangalatsa. . Mothandizidwa ndi mapu a FIB-SEM ndi EDS, monga momwe chithunzi 3m chikuwonera, idawona zinthu zambiri za F mumtundu wa 3D pamwamba pa F-NMC811.

Chithunzi 4a) Kugawa kwakuya kwa Elementi pamwamba pa ma elekitirodi abwino a NMC811. (ac) FIB-TOF-SIMS ikusokoneza kugawa kwa F, O, ndi Li element mu elekitirodi yabwino ya NMC811. (df) Maonekedwe a pamwamba ndi kufalikira kwakuya kwa F, O, ndi Li element za NMC811.

FIB-TOF-SEM idawululanso kufalikira kwakuya kwazinthu pamtunda wa elekitirodi yabwino ya NMC811 (Chithunzi 4). Poyerekeza ndi zitsanzo zoyambirira ndi C-NMC811, kuwonjezeka kwakukulu kwa chizindikiro cha F kunapezeka pamtunda wapamwamba wa F-NMC811 (Chithunzi 4a). Kuonjezera apo, zizindikiro zofooka za O ndi zapamwamba za Li pamwamba zimasonyeza mapangidwe a F- ndi Li-rich CEI zigawo (Chithunzi 4b, c). Zotsatira zonsezi zidatsimikizira kuti F-NMC811 ili ndi wosanjikiza wa LiF-rich CEI. Poyerekeza ndi CEI ya C-NMC811, gawo la CEI la F-NMC811 lili ndi zinthu zambiri za F ndi Li. Kuphatikiza apo, monga zikuwonetsedwa mu FIGS. 4d-f, malinga ndi kuya kwa ion etching, kapangidwe ka NMC811 koyambirira ndi kolimba kuposa kosangalatsa kwa NMC811. Kuzama kwa F-NMC811 wakale ndi kocheperako kuposa C-NMC811, zomwe zikutanthauza kuti F-NMC811 ili ndi kukhazikika kwadongosolo.

Chithunzi 5 CEI mankhwala opangidwa pamwamba pa ma elekitirodi abwino a NMC811. (a) XPS sipekitiramu ya NMC811 positive electrode CEI. (bc) XPS C1s ndi F1s mawonekedwe a NMC811 yosangalatsa ya elekitirodi CEI. (d) Cryo-transmission electron microscope: kugawa zinthu kwa F-NMC811. (e) Chithunzi cha TEM chozizira cha CEI chopangidwa pa F-NMC81. (fg) Zithunzi za STEM-HAADF ndi STEM-ABF za C-NMC811. (hi) Zithunzi za STEM-HAADF ndi STEM-ABF za F-NMC811.

Adagwiritsa ntchito XPS kuzindikiritsa kapangidwe kake ka CEI mu NMC811 (Chithunzi 5). Mosiyana ndi C-NMC811 yoyambirira, CEI ya F-NMC811 ili ndi F ndi Li yayikulu koma C yaying'ono (Chithunzi 5a). Kuchepa kwa mitundu ya C kukuwonetsa kuti LiF-rich CEI imatha kuteteza F-NMC811 pochepetsa mayendedwe okhazikika am'mbali ndi ma electrolyte (Chithunzi 5b). Kuphatikiza apo, zocheperako za CO ndi C=O zikuwonetsa kuti solvolysis ya F-NMC811 ndi yochepa. Mu mawonekedwe a F1s a XPS (Chithunzi 5c), F-NMC811 inasonyeza chizindikiro champhamvu cha LiF, kutsimikizira kuti CEI ili ndi kuchuluka kwa LiF yochokera ku zosungunulira za fluorinated. Kujambula kwazinthu za F, O, Ni, Co, ndi Mn m'dera lanu pa F-NMC811 tinthu tating'onoting'ono tikuwonetsa kuti tsatanetsataneyo amagawidwa mofanana (Chithunzi 5d). Chithunzi cha TEM chotsika kutentha mu Chithunzi 5e chikuwonetsa kuti CEI imatha kukhala ngati gawo loteteza kuti liphimbe mofanana ndi ma elekitirodi abwino a NMC811. Pofuna kutsimikiziranso kusinthika kwa mawonekedwe a mawonekedwe, kuyesa kozungulira kozungulira kozungulira kozungulira kamdima kakang'ono (HAADF-STEM) ndi zozungulira zozungulira zowala zowunikira ma electron microscopy (ABF-STEM) zidachitika. -NMC811), Pamwamba pa ma elekitirodi ozungulira ozungulira asintha kwambiri, ndipo gawo la mchere wosasinthika wamwala amaunjikana pamwamba pa ma elekitirodi abwino (Chithunzi 5f). Electrode yabwino imakhala ndi mawonekedwe osanjikiza (Chithunzi 811h), kuwonetsa zovulaza Gawoli limakhala loponderezedwa bwino. CEI wosanjikiza pa ma elekitirodi abwino pamwamba pa NMC5 mu electrolyte perfluorinated.

Chithunzi 6a) TOF-SIMS sipekitiramu wa interphase gawo pamwamba pa NMC811 zabwino elekitirodi. (ac) Kusanthula mozama kwa zidutswa za ion yachiwiri pa electrode yabwino ya NMC811. (df) TOF-SIMS chemical spectrum ya ion fragment yachiwiri pambuyo pa masekondi 180 a sputtering pa choyambirira, C-NMC811 ndi F-NMC811.

Zidutswa za C2F nthawi zambiri zimatengedwa ngati organic zinthu za CEI, ndipo LiF2- ndi PO2-zidutswa nthawi zambiri zimawonedwa ngati zamoyo zopanda chilengedwe. Zizindikiro zokwezeka kwambiri za LiF2- ndi PO2- zidapezedwa pakuyesako (Chithunzi 6a, b), kuwonetsa kuti gawo la CEI la F-NMC811 lili ndi mitundu yambiri yamitundu yosiyanasiyana. M'malo mwake, C2F-signal ya F-NMC811 ndi yofooka kuposa C-NMC811 (Chithunzi 6c), kutanthauza kuti CEI wosanjikiza wa F-NMC811 uli ndi mitundu yochepa yosalimba. Kafukufuku wowonjezera adapeza (Chithunzi 6d-f) kuti pali zamoyo zambiri za inorganic mu CEI ya F-NMC811, pomwe pali mitundu yocheperako mu C-NMC811. Zotsatira zonsezi zikuwonetsa kupangidwa kwa gawo lolimba la CEI lolimba mu perfluorinated electrolyte. Poyerekeza ndi batire yapaketi yofewa ya NMC811/Gr yogwiritsa ntchito electrolyte yachikhalidwe, kuwongolera kwachitetezo cha batire yofewa pogwiritsa ntchito ma electrolyte opangidwa ndi perfluorinated kungabwere chifukwa cha: Choyamba, kupanga mu-situ kwa CEI wosanjikiza wolemera mu inorganic LiF ndikopindulitsa. Kukhazikika kwachilengedwe kwamafuta a electrode yosangalatsa ya NMC811 kumachepetsa kutulutsa kwa okosijeni wa lattice chifukwa cha kusintha kwa gawo; Kachiwiri, olimba zosawerengeka CEI zoteteza wosanjikiza kumalepheretsa kwambiri zotakasika delithiation NMC811 kukhudzana electrolyte, kuchepetsa exothermic mbali anachita; chachitatu, The perfluorinated electrolyte ali mkulu matenthedwe bata pa kutentha kwambiri.

Kutsiliza ndi Chiyembekezo

Ntchitoyi inanena za kupangidwa kwa batire yamtundu wa Gr/NMC811 ya thumba lathunthu pogwiritsa ntchito electrolyte yopangidwa ndi perfluorinated, yomwe idathandizira kwambiri chitetezo chake. Intrinsic matenthedwe bata. Kafukufuku wozama wa TR inhibition mechanism komanso kulumikizana pakati pa zida ndi milingo ya batri. Kukalamba sikukhudza kutentha kwa TR trigger (T2) ya batire ya electrolyte perfluorinated panthawi yonse ya mkuntho, yomwe ili ndi ubwino woonekera pa batri yokalamba pogwiritsa ntchito electrolyte yachikhalidwe. Kuphatikiza apo, nsonga ya exothermic imagwirizana ndi zotsatira za TR, zomwe zikuwonetsa kuti CEI yamphamvu imathandizira kukhazikika kwamafuta a electrode opanda lifiyamu ndi zida zina za batri. Zotsatirazi zikuwonetsa kuti mawonekedwe owongolera a in-situ a wosanjikiza wokhazikika wa CEI ali ndi tanthauzo lofunikira pakugwiritsira ntchito moyenera mabatire a lithiamu amphamvu kwambiri.

Zambiri zamabuku

Ma Interphase Omangidwa A Ultraconformal Yambitsani Mabatire a Lithium Otetezeka Kwambiri, Zida Zosungira Mphamvu, 2021.