Source: new energy leader, by
Tanthauzo: panopa, ndi lifiyamu mchere mu malonda lifiyamu-ion batire electrolyte makamaka LiPF6 ndi LiPF6 apereka electrolyte kwambiri electrochemical ntchito, koma LiPF6 ali osauka matenthedwe ndi mankhwala bata, ndipo tcheru kwambiri madzi.
Pakali pano, mchere wa lithiamu mu malonda a lithiamu-ion batire electrolyte makamaka LiPF6 ndi LiPF6 apereka electrolyte kwambiri electrochemical ntchito.Komabe, LiPF6 ilibe kukhazikika kwamafuta ndi mankhwala, ndipo imakhudzidwa kwambiri ndi madzi.Pansi pa zochita za H2O pang'ono, zinthu za asidi monga HF zidzawonongeka, ndiyeno zinthu zabwino zidzawonongeka, ndipo zitsulo zosinthika zidzasungunuka, ndipo pamwamba pa electrode zoipa zidzasamutsidwa kuwononga filimu ya SEI. , Zotsatira zimasonyeza kuti filimu ya SEI ikupitirizabe kukula, zomwe zimabweretsa kuchepa kosalekeza kwa mphamvu ya mabatire a lithiamu-ion.
Pofuna kuthana ndi mavutowa, anthu akuyembekeza kuti mchere wa lithiamu wa imide wokhala ndi H2O wokhazikika komanso kukhazikika kwamafuta ndi mankhwala, monga mchere wa lithiamu monga LiTFSI, lifsi ndi liftfsi, ndizochepa chifukwa cha mtengo ndi anions a mchere wa lithiamu. monga LiTFSI sangathe kuthetsedwa chifukwa cha dzimbiri Al zojambulazo, etc., LiTFSI lithiamu mchere sanagwiritsidwe ntchito.Posachedwapa, VARVARA sharova wa labotale ya Germany HIU yapeza njira yatsopano yogwiritsira ntchito imide ya mchere wa lithiamu monga zowonjezera za electrolyte.
The otsika kuthekera graphite zoipa elekitirodi mu Li-ion batire zidzachititsa kuwonongeka kwa electrolyte pamwamba pake, kupanga passivation wosanjikiza, amene amatchedwa SEI filimu.SEI filimu angalepheretse electrolyte kuwonongeka padziko zoipa, kotero bata la SEI filimu ali ndi chikoka kwambiri pa mkombero bata la lithiamu-ion mabatire.Ngakhale mchere wa lithiamu monga LiTFSI sungagwiritsidwe ntchito ngati solute wa electrolyte yamalonda kwa kanthawi, wakhala ukugwiritsidwa ntchito monga zowonjezera ndipo wapeza zotsatira zabwino kwambiri.Kuyesa kwa VARVARA sharova kunapeza kuti kuwonjezera 2wt% LiTFSI mu electrolyte kungathe kupititsa patsogolo kayendedwe ka batire la lifepo4/graphite: mizungulire 600 pa 20 ℃ ndipo kuchepa kwa mphamvu kumakhala kosakwana 2%.Mu gulu lolamulira, electrolyte yokhala ndi 2wt% VC yowonjezera imawonjezedwa.Pazifukwa zomwezo, kuchepa kwa mphamvu ya batri kumafika pafupifupi 20%.
Pofuna kutsimikizira zotsatira za zowonjezera zosiyanasiyana pa ntchito ya mabatire a lithiamu-ion, gulu lopanda kanthu lp30 (EC: DMC = 1: 1) popanda zowonjezera ndi gulu loyesera ndi VC, LiTFSI, lifsi ndi liftfsi linakonzedwa ndi varvarvara sharova. motsatira.Kuchita kwa ma electrolyte awa kudawunikidwa ndi batani theka la cell ndi cell yathunthu.
Chithunzi pamwambapa chikuwonetsa ma voltammetric curve a ma electrolyte a gulu lolamulira lopanda kanthu komanso gulu loyesera.Panthawi yochepetsera, tinawona kuti chiwongoladzanja chodziwikiratu chikuwonekera mu electrolyte ya gulu lopanda kanthu pafupifupi 0.65v, lolingana ndi kuchepetsa kuwonongeka kwa zosungunulira za EC.Kuwonongeka kwaposachedwa kwa gulu loyesera ndi chowonjezera cha VC chinasunthira ku kuthekera kwakukulu, zomwe makamaka chifukwa chakuti mphamvu yowonongeka ya VC yowonjezera inali yoposa ya EC, Choncho, kuwonongeka kunachitika poyamba, komwe kunateteza EC.Komabe, mipiringidzo ya voltammetric ya electrolyte yowonjezeredwa ndi LiTFSI, zowonjezera za lifsi ndi littfsi sizinali zosiyana kwambiri ndi za gulu lopanda kanthu, zomwe zimasonyeza kuti zowonjezera za imide sizingachepetse kuwonongeka kwa zosungunulira za EC.
Chithunzi pamwambapa chikuwonetsa magwiridwe antchito a electrochemical a graphite anode mu ma electrolyte osiyanasiyana.Kuchokera pakuchita bwino kwa chiwongolero choyamba ndi kutulutsa, mphamvu ya coulomb ya gulu lopanda kanthu ndi 93.3%, mphamvu yoyamba ya electrolyte ndi LiTFSI, lifsi ndi liftfsi ndi 93.3%, 93.6% ndi 93.8%, motsatana.Komabe, mphamvu yoyamba ya electrolyte yokhala ndi zowonjezera za VC ndi 91.5% yokha, yomwe ili makamaka chifukwa panthawi yoyamba ya lifiyamu intercalation ya graphite, VC imawola pamwamba pa graphite anode ndipo imadya kwambiri Li.
The zikuchokera SEI filimu adzakhala ndi chikoka chachikulu pa madutsidwe ionic, ndiyeno zimakhudza mlingo ntchito Li ion batire.Pakuyesa kwa magwiridwe antchito, zidapezeka kuti ma electrolyte okhala ndi lifsi ndi zowonjezera za liftfsi ali ndi mphamvu yotsika pang'ono kuposa ma electrolyte ena omwe amatuluka kwambiri.Pakuyesa kwa C / 2, magwiridwe antchito a ma elekitirodi onse okhala ndi zowonjezera zowonjezera amakhala okhazikika, pomwe mphamvu ya ma electrolyte okhala ndi zowonjezera za VC imachepa.
Pofuna kuwunika kukhazikika kwa electrolyte munthawi yayitali ya batire ya lithiamu-ion, VARVARA sharova adakonzekeranso LiFePO4 / graphite cell cell yokhala ndi batani, ndikuwunika magwiridwe antchito a electrolyte ndi zowonjezera zosiyanasiyana pa 20 ℃ ndi 40 ℃.Zotsatira zake zikuwonetsedwa mu tebulo ili m'munsimu.Zitha kuwoneka kuchokera patebulo kuti mphamvu ya electrolyte yokhala ndi zowonjezera za LiTFSI ndizokwera kwambiri kuposa zowonjezera za VC kwa nthawi yoyamba, komanso kuyendetsa njinga pa 20 ℃ ndikokulirapo.Mphamvu yosungira mphamvu ya electrolyte yokhala ndi zowonjezera za LiTFSI ndi 98.1% pambuyo pa mizungu 600, pomwe mphamvu yosungira mphamvu ya electrolyte yokhala ndi zowonjezera za VC ndi 79.6% yokha.Komabe, mwayi umenewu umatha pamene electrolyte yazunguliridwa pa 40 ℃, ndipo ma electrolyte onse ali ndi ntchito yofanana yoyendetsa njinga.
Kuchokera kusanthula pamwambapa, sikovuta kuwona kuti mayendedwe a batire ya lithiamu-ion amatha kusintha kwambiri pamene mchere wa lithiamu imide umagwiritsidwa ntchito ngati chowonjezera cha electrolyte.Pofuna kuphunzira zochita limagwirira wa zina monga LiTFSI mu mabatire lithiamu-ion, VARVARA sharova kusanthula zikuchokera SEI filimu anapanga padziko graphite anode mu electrolyte osiyana XPS.Chithunzi chotsatira chikuwonetsa zotsatira za kusanthula kwa XPS za filimu ya SEI yomwe idapangidwa pamwamba pa anode ya graphite itatha kuzungulira koyamba ndi 50th.Zitha kuwoneka kuti zomwe zili mu LIF mufilimu ya SEI yopangidwa mu electrolyte yokhala ndi zowonjezera za LiTFSI ndizokwera kwambiri kuposa zomwe zili mu electrolyte yokhala ndi zowonjezera za VC.Kusanthula kwina kochulukira kwa kapangidwe ka filimu ya SEI kukuwonetsa kuti dongosolo la zinthu za LIF mu filimu ya SEI ndi lifsi> liftfsi> LiTFSI> VC> gulu lopanda kanthu pambuyo pa kuzungulira koyamba, koma filimu ya SEI sisinthika pambuyo polipira koyamba.Pambuyo pa 50 cycle, LIF zomwe zili mufilimu ya SEI mu lifsi ndi liftfsi electrolyte zidatsika ndi 12% ndi 43%, motsatira, pamene LIF zomwe zili mu electrolyte zowonjezeredwa ndi LiTFSI zidakwera ndi 9%.
Nthawi zambiri, timaganiza kuti mawonekedwe a nembanemba ya SEI amagawidwa m'magulu awiri: wosanjikiza wamkati wamkati ndi wosanjikiza wakunja wachilengedwe.Wosanjikiza wopangidwa ndi inorganic amapangidwa makamaka ndi LIF, Li2CO3 ndi zida zina za inorganic, zomwe zimakhala ndi magwiridwe antchito abwino a electrochemical komanso ma ionic conductivity apamwamba.Kunja organic wosanjikiza makamaka wapangidwa ndi porous electrolyte kuwonongeka ndi polymerization mankhwala, monga roco2li, PEO ndi zina zotero, amene alibe chitetezo champhamvu kwa electrolyte, Choncho, tikukhulupirira kuti SEI nembanemba muli zigawo zambiri inorganic.Zowonjezera za Imide zimatha kubweretsa zigawo zambiri za LIF ku nembanemba ya SEI, zomwe zimapangitsa kuti mawonekedwe a SEI akhale okhazikika, amatha kuteteza kuwonongeka kwa ma electrolyte mumayendedwe a batri, kuchepetsa kugwiritsa ntchito kwa Li, ndikuwongolera kwambiri kayendedwe ka batri.
Monga zowonjezera za electrolyte, makamaka zowonjezera za LiTFSI, mchere wa lithiamu wotsamira ukhoza kupititsa patsogolo kayendedwe ka batri.Izi makamaka chifukwa chakuti SEI filimu anapanga padziko graphite anode ali kwambiri LIF, woonda ndi khola SEI filimu, amene amachepetsa kuwonongeka kwa electrolyte ndi kuchepetsa kukana mawonekedwe.Komabe, kuchokera pamayesero aposachedwa, zowonjezera za LiTFSI ndizoyenera kugwiritsidwa ntchito kutentha kutentha.Pa 40 ℃, zowonjezera za LiTFSI zilibe mwayi wodziwikiratu kuposa zowonjezera za VC.
Nthawi yotumiza: Apr-15-2021