Umthombo: inkokeli entsha yamandla, ngu
Ubungqina obucacileyo: okwangoku, iityuwa ze-lithium kwi-electrolyte yebhetri ye-lithium-ion ikakhulu i-LiPF6 kunye ne-LiPF6 zinike ukusebenza kwe-electrolyte okugqwesileyo kwe-electrochemical, kodwa i-LiPF6 inozinzo olubi lwe-thermal kunye neekhemikhali, kwaye inovelwano kakhulu emanzini.
Okwangoku, iityuwa ze-lithium kwi-electrolyte yebhetri ye-lithium-ion ikakhulu yi-LiPF6 kunye ne-LiPF6 zinike ukusebenza kakuhle kwe-electrolyte ye-electrochemical.Nangona kunjalo, i-LiPF6 inozinzo olulambathayo lwe-thermal kunye neekhemikhali, kwaye inochuku kakhulu emanzini.Ngaphantsi kwesenzo sesixa esincinci se-H2O, izinto ze-asidi ezifana ne-HF ziya kuchithwa, kwaye ke izinto ezilungileyo ziya kugqwala, kwaye izinto zetsimbi zenguqu ziya kuchithwa, kwaye umphezulu we-electrode engalunganga iya kufuduswa ukutshabalalisa ifilimu ye-SEI. , Iziphumo zibonisa ukuba ifilimu ye-SEI iyaqhubeka ikhula, ekhokelela ekuhlahleni okuqhubekayo kwamandla ebhetri ye-lithium-ion.
Ukuze boyise ezi ngxaki, abantu banethemba lokuba iityuwa ze-lithium ze-imide kunye ne-H2O ezinzile ngakumbi kunye nokuzinza okungcono kwe-thermal kunye neekhemikhali, ezifana neetyuwa ze-lithium ezifana ne-LiTFSI, i-lifsi kunye ne-lifsi, zilinganiselwe yindleko kunye nee-anions ze-lithium salts. njengeLiTFSI ayinakusonjululwa ngenxa ye-corrosion ye-Al foil, njl., iLiTFSI lithium ityuwa ayizange isetyenziswe ekusebenzeni.Kungekudala, i-VARVARA sharova yebhubhoratri yaseJamani ye-HIU ifumene indlela entsha yokusetyenziswa kwe-imide i-lithium salts njengezongezo ze-electrolyte.
Ukubanakho okuphantsi kwegraphite negative electrode kwibhetri ye-Li-ion kuya kukhokelela ekuboleni kwe-electrolyte kumphezulu wayo, yenze umaleko wokudlula, obizwa ngokuba yifilimu ye-SEI.Ifilimu ye-SEI inokuthintela ukubola kwe-electrolyte kwindawo engafanelekanga, ngoko ukuzinza kwefilimu ye-SEI kunempembelelo ebalulekileyo kumjikelezo wokuzinza kweebhetri ze-lithium-ion.Nangona iityuwa ze-lithium ezifana ne-LiTFSI ayinakusetyenziswa njenge-solute ye-electrolyte yorhwebo okwethutyana, isetyenziswe njengezongezo kwaye ifumene iziphumo ezilungileyo kakhulu.Uvavanyo lwe-VARVARA sharova lufumanise ukuba ukongeza i-2wt% ye-LiTFSI kwi-electrolyte kunokuphucula ngokusebenzayo ukusebenza komjikelo we-lifepo4/ibhetri yegraphite: imijikelo engama-600 kuma-20 ℃ kwaye ukuhla kwamandla kungaphantsi kwe-2%.Kwiqela lolawulo, i-electrolyte ene-2wt% ye-VC additive iyongezwa.Ngaphantsi kweemeko ezifanayo, ukuhla kwamandla ebhetri kufikelela malunga ne-20%.
Ukuze kuqinisekiswe umphumo wezongezo ezahlukeneyo ekusebenzeni kweebhetri ze-lithium-ion, iqela elingenanto lp30 (EC: DMC = 1: 1) ngaphandle kwezongezo kunye neqela lokulinga kunye ne-VC, i-LiTFSI, i-lifsi kunye ne-lifsi yalungiswa ngu-varvarvara sharova. ngokulandelelanayo.Ukusebenza kwezi electrolyte kwavavanywa ngeqhosha lesiqingatha seli kunye neseli epheleleyo.
Umzobo ongentla ubonisa i-voltammetric curves ye-electrolytes yeqela elingenanto yokulawula kunye neqela lokulinga.Ngethuba lenkqubo yokunciphisa, siqaphele ukuba i-peak yangoku ebonakalayo ibonakala kwi-electrolyte yeqela elingenanto malunga ne-0.65v, ehambelana nokunciphisa ukuchithwa kwe-solvent ye-EC.Incopho yangoku yokubola yeqela lovavanyo kunye ne-VC additive itshintshelwe kwikhono eliphezulu, okwakungenxa yokuba i-voltage yokubola ye-additive ye-VC yayiphezulu kunaleyo ye-EC, Ngoko ke, ukubola kwenzeka kuqala, okwakukhusela i-EC.Nangona kunjalo, i-voltammetric curves ye-electrolyte eyongezwe kunye ne-LiTFSI, i-lifsi kunye ne-littfsi izongezo azizange zihluke kakhulu kwiqela elingenanto, elibonisa ukuba izongezo ze-imide azikwazi ukunciphisa ukubola kwe-solvent ye-EC.
Lo mzobo ungasentla ubonisa ukusebenza kwe-electrochemical ye-graphite anode kwii-electrolytes ezahlukeneyo.Ukususela ekusebenzeni kakuhle kwentlawulo yokuqala kunye nokukhutshwa, ukusebenza kakuhle kwe-coulomb yeqela elingenanto yi-93.3%, ukusebenza kakuhle kokuqala kwe-electrolytes kunye ne-LiTFSI, i-lifsi kunye ne-lifsi yi-93.3%, 93.6% kunye ne-93.8%, ngokulandelanayo.Nangona kunjalo, ukusebenza kakuhle kokuqala kwe-electrolytes nge-additive ye-VC yi-91.5% kuphela, nto leyo ibangelwa kukuba ngexesha lokuqala lokudibanisa i-lithium ye-graphite, i-VC ibola kumphezulu we-graphite anode kwaye idla i-Li ngaphezulu.
Ukuqulunqwa kwefilimu ye-SEI kuya kuba nefuthe elikhulu kwi-ionic conductivity, kwaye emva koko kuchaphazela izinga lokusebenza kwebhetri ye-Li ion.Kuvavanyo lomgangatho wokusebenza, kufumaniseka ukuba i-electrolyte ene-lifsi kunye ne-lifsi izongezo zinomthamo ophantsi kancinci kunezinye i-electrolyte ekuphumeni okuphezulu kwangoku.Kuvavanyo lomjikelo we-C / 2, ukusebenza komjikelo wazo zonke ii-electrolyte ezinezongezo ze-imide zizinzile, ngelixa amandla e-electrolytes anezongezo ze-VC ayancipha.
Ukuze uvavanye ukuzinza kwe-electrolyte kumjikelezo wexesha elide webhetri ye-lithium-ion, i-VARVARA sharova nayo ilungiselele i-LiFePO4 / i-graphite iseli epheleleyo kunye neseli yeqhosha, kwaye ivavanya ukusebenza komjikelo we-electrolyte ngezongezo ezahlukeneyo kwi-20 ℃ kunye ne-40 ℃.Iziphumo zovavanyo ziboniswe kwitheyibhile engezantsi.Inokubonwa kwitheyibhile ukuba ukusebenza kakuhle kwe-electrolyte kunye ne-LiTFSI additive iphezulu kakhulu kunokongezwa kwe-VC okokuqala, kwaye ukusebenza kwebhayisikile kwi-20 ℃ kungaphezulu.Izinga lokugcinwa komthamo we-electrolyte kunye ne-LiTFSI additive yi-98.1% emva kwemijikelo engama-600, ngelixa izinga lokugcinwa kwe-electrolyte kunye ne-VC additive yi-79.6% kuphela.Nangona kunjalo, le nzuzo iyanyamalala xa i-electrolyte ijikelezwe kwi-40 ℃, kwaye zonke i-electrolyte zinomsebenzi ofanayo wokuhamba ngebhayisikile.
Ukususela kolu hlalutyo lungentla, akunzima ukubona ukuba ukusebenza komjikelo webhetri ye-lithium-ion kunokuphuculwa kakhulu xa i-lithium imide ityuwa isetyenziswa njenge-electrolyte additive.Ukuze ufunde indlela yokusebenza yezongezo ezifana ne-LiTFSI kwiibhetri ze-lithium-ion, i-VARVARA sharova ihlalutye ukubunjwa kwefilimu ye-SEI eyenziwe kumphezulu we-graphite anode kwii-electrolyte ezahlukeneyo nge-XPS.Lo mzobo ulandelayo ubonisa iziphumo zohlalutyo lwe-XPS zefilimu ye-SEI eyenziwe kumphezulu we-graphite anode emva komjikelo wokuqala nowama-50.Ingabonwa ukuba umxholo we-LIF kwifilimu ye-SEI eyenziwe kwi-electrolyte ene-additive ye-LiTFSI iphezulu kakhulu kunoko kwi-electrolyte ene-additive VC.Uhlalutyo olongezelelweyo lobungakanani bokubunjwa kwefilimu ye-SEI lubonisa ukuba umyalelo we-LIF umxholo kwifilimu ye-SEI lifsi> liftfsi> LiTFSI> VC> iqela elingenanto emva komjikelezo wokuqala, kodwa ifilimu ye-SEI ayinakuguquguquka emva kwentlawulo yokuqala.Emva kwemijikelezo ye-50, umxholo we-LIF wefilimu ye-SEI kwi-lifsi kunye ne-liftfsi electrolyte yehla nge-12% kunye ne-43%, ngokulandelanayo, ngelixa umxholo we-LIF we-electrolyte wongezwa nge-LiTFSI unyuke nge-9%.
Ngokubanzi, sicinga ukuba ulwakhiwo lwe-membrane ye-SEI lwahlulwe lube ngamacandelo amabini: umaleko wangaphakathi we-inorganic kunye nomgangatho ongaphandle we-organic.Umaleko we-inorganic uqulunqwe ikakhulu yi-LIF, i-Li2CO3 kunye nezinye izinto ezingaphiliyo, ezinomsebenzi ongcono we-electrochemical kunye ne-ionic conductivity ephezulu.Umaleko ongaphandle organic iqulathe ikakhulu porous ukubola electrolyte kunye neemveliso polymerization, ezifana roco2li, PEO njalo njalo, engenalo ukhuselo oluqinileyo electrolyte, Ngoko ke, sinethemba lokuba inwebu SEI iqulathe amacandelo inorganic ngaphezulu.Izongezo ze-Imide zinokuzisa amacandelo angaphezulu kwe-LIF kwi-membrane ye-SEI, eyenza ukwakheka kwe-membrane ye-SEI izinze ngakumbi, inokuthintela ngcono ukubola kwe-electrolyte kwinkqubo yomjikelo webhetri, ukunciphisa ukusetyenziswa kwe-Li, kunye nokuphucula kakhulu ukusebenza komjikelo webhetri.
Njengezongezo ze-electrolyte, ngakumbi izongezo ze-LiTFSI, iityuwa ze-lithium zingaphucula kakhulu ukusebenza komjikelo webhetri.Oku ikakhulu ngenxa yokuba ifilimu SEI eyenziwe kumphezulu yegraphite anode ngaphezu LIF, obhityileyo kwaye uzinzile ngakumbi ifilimu SEI, nto leyo enciphisa ukubola electrolyte kunye nokunciphisa ujongano ukumelana.Nangona kunjalo, ukusuka kwidatha yovavanyo yangoku, isongezo se-LiTFSI sikulungele ngakumbi ukusetyenziswa kwiqondo lokushisa.Kwi-40 ℃, isongezelelo se-LiTFSI asinanzuzo icacileyo ngaphezulu kwesongezo seVC.
Ixesha lokuposa: Apr-15-2021