Yintoni i-electrolyte kwibhetri ye-lithium?

Yintoni i-electrolyte kwibhetri ye-lithium?

i-electrolyte

I-electrolyte ekwibhetri ye-lithium -ingumthuthi wee-ion ebhetrini. Ngokuqhelekileyo iqulunqwe ngeetyuwa ze-lithium, izinyibilikisi zezinto eziphilayo, kunye nezongezo, njengoko kubonisiwe kuMfanekiso 7{3}}4. I-electrolyte idlala indima ebalulekileyo ekuqhubeni ii-ion phakathi kwee-electrode ezilungileyo nezingalunganga ze-lithium -ibhetri ye-ion, iqinisekisa iingenelo zayo ezifana nombane ophezulu kunye namandla athile aphezulu. I-Electrolytes idla ngokulungiswa phantsi kweemeko ezithile kwaye ngokwemilinganiselo ethile ukusuka phezulu{8}}kucoceko lwezinyibilikisi zezinto eziphilayo, iityuwa zelithium, kunye nezongezo eziyimfuneko. Ngelixa izixhobo ze-electrode zimisela ubuninzi bamandla ebhetri, i-electrolyte imisela ngokusisiseko ubomi bayo bomjikelezo, ukusebenza okuphezulu kunye nobushushu obuphantsi, kunye nokhuseleko. Ukubunjwa okusisiseko kwe-electrolyte kuhlala kungatshintshi; i-innovation ikakhulu ilele ekuphuhlisweni kweetyuwa ze-lithium zenoveli kunye nezongezo, kunye nokuqonda okunzulu kweenkqubo zemichiza ye-interfacial kunye neendlela ezibandakanyekayo kwiibhetri ze-lithium-ion.

Kukho iintlobo ezininzi zeetyuwa ze-lithium, njengoko kubonisiwe kuMfanekiso 7{1}}5, kodwa zimbalwa kakhulu ezisetyenziswa kwiibhetri ze-lithium-ion ezithengiswayo. Ityuwa ye-lithium efanelekileyo kufuneka ibe nezi zinto zilandelayo:

I-1) Idigri yobudlelwane obuphantsi, i-soluble ngokulula kwi-solvents ye-organic, iqinisekisa ukuhanjiswa kwe-ionic ephezulu ye-electrolyte.

2) I-Anions ene-antioxidant kunye nokunciphisa ukuchasana; iimveliso ezincitshisiweyo ziququzelela ukwakhiwa kwefilimu ezinzileyo, ephantsi ye-SEI enokuxhathisa.

I-3) Uzinzo oluhle lweekhemikhali, ngaphandle kokubangela ukuphendulwa kwecala eliyingozi kunye nezixhobo ze-electrode, i-electrolytes, okanye i-separators.

4) Inkqubo elula yamalungiselelo, ixabiso eliphantsi, {1}engenatyhefu kunye nongcoliseko{2}}simahla.

I-LiPF6 yeyona tyuwa yelithium isetyenziswa kakhulu. Ngelixa iipropathi zayo ezizimeleyo zingeyiyo eyona ibalaseleyo, ibonisa ukusebenza ngokugqibeleleyo ngokubanzi kwi-carbonate exubeneyo ye-solvent electrolytes. I-LiPF6 inezi zibonelelo ziphambili zilandelayo:

1) Ukunyibilika okufanelekileyo kunye nokuhanjiswa okuphezulu kwe-ionic kwizinyibilikisi ezingezizo{1}}ezimanzi.

2) Iyakwazi ukwenza ifilimu ezinzileyo ye-passivation ebusweni be-aluminium foil abaqokeleli bangoku.

I-3) I-synergistically yenza ifilimu ye-SEI ezinzileyo kwi-graphite electrode surface kunye ne-carbonate solvents.

Nangona kunjalo, i-LiPF6 inozinzo olulambathayo lwe-thermal kwaye ithanda ukubola. I-Byproducts inokonakalisa ifilimu ye-SEI kwindawo ye-electrode, inyibilikise i-electrode esebenzayo amacandelo asebenzayo, kwaye ikhokelele ekuboleni kwamandla ngexesha lokuhamba ngebhayisikili.

I-LiBF ikwasisongezo setyuwa se-lithium esisetyenziswa ngokuqhelekileyo. Xa kuthelekiswa ne-LiPF6, i-LiBF inoluhlu olubanzi lobushushu lokusebenza, olungcono{2}}nozinzo lobushushu obuphezulu, kunye nokusebenza okuphezulu{3}} kobushushu obuphantsi. I-LiBF ine-conductivity ephezulu, ifestile ebanzi ye-electrochemical, kunye nokuzinza okuhle kwe-thermal. Olona ncedo lwayo lukhulu lukwifilim{6} zokwenza iipropati, njengoko inokuthatha inxaxheba ngokuthe ngqo ekuyilweni kwefilimu ye-SEI.

Ngokwesakhiwo, i-LiDFOB yenziwe ngesiqingatha-imolekyuli ze-LiBOB kunye ne-LiBF, idibanisa iingenelo zefilimu elungileyo{1}}ekukwenza iipropathi ze-LiBOB kunye nomgangatho olungileyo osezantsi{2}}ukusebenza kwe-LiBF4. Xa kuthelekiswa ne-LiBOB, i-LiDFOB ine-solubility ephezulu kwi-linear carbonate solvents kunye ne-electrolyte conductivity ephezulu. Ubushushu bayo obuphezulu-kunye{6}}nobushushu obuphantsi{6}}intsebenzo yayo ingcono kune-LiPF4, kwaye iyahambelana kakuhle necathode yebhetri, yenze ifilimu yokudlula kwifoyile yealuminiyam kwaye inqanda i-electrolyte oxidation.

Amaqela e-CF₃SO₂ kulwakhiwo lwe-LiTFSI ane-electron eyomeleleyo{0}}isiphumo sokurhoxisa, esenza mandundu ukuchithwa kwentlawulo embi kunye nokunciphisa ukubhanqa kombutho we-ion, okukhokelela ekunyibilikeni okuphezulu kwetyuwa. Ngapha koko, i-LiTFSI ine-conductivity ephezulu yombane, iqondo lobushushu eliphezulu lokubola kwe-thermal, kwaye ayifakwanga lula i-hydrolyzed; nangona kunjalo, iya kutshabalalisa kakhulu abaqokeleli be-aluminium yangoku kumbane ongaphezulu kwe-3.7V.

Iiathom zefluorine kwimolekyuli ye-LiFSI zineepropathi ezomeleleyo ze-electron{0} zokurhoxisa, ezisusa intlawulo engalunganga kwi-N, ekhokelela kumanyano lwe-ion olubuthathaka kunye nokwahlulwa lula kwe-Li+, nto leyo ekhokelela ekuqhubeni okuphezulu.

I-LiPO2F2 ibonisa ukusebenza kakuhle okusezantsi{2}}kweqondo lobushushu kwaye iphucula nokusebenza okuphezulu{3}}kobushushu be-electrolyte. Njengokongeza, inokwenza ifilimu ye-SEI etyebileyo kwi-LixPOyFz kunye ne-LiF kumphezulu we-electrode engalunganga, enceda ukunciphisa i-impedance yebhetri kunye nokuphucula ukusebenza komjikelo webhetri. Nangona kunjalo, i-LiPO2F2 ikwanengxaki yokunyibilika okuphantsi.

Icandelo eliphambili lei-electrolyte engamanzisisinyibilikisi se-organic, esinyibilikisa iityuwa ze-lithium kwaye ibonelela nge-carrier ye-lithium ion. Isinyibilikisi esifanelekileyo se-lithium{1}}ye-electrolyte yebhetri yeion kufuneka sihlangabezane nezi meko zilandelayo:

I-1) I-dielectric ephezulu engaguqukiyo kunye nokukwazi ukunyibilika okunamandla kwiityuwa ze-lithium.

I-2) Indawo encibilikayo ephantsi kunye neqondo eliphezulu lokubilisa, ukugcina i-liquid state phezu kweqondo lokushisa elibanzi.

3) I-viscosity ephantsi, iququzelela i-lithium - yothutho lwe-ion.

I-4) Ukuzinza kweekhemikhali ezilungileyo, akulonakalisi isakhiwo se-electrode esilungileyo okanye esibi okanye ukuchithwa kwezinto ezilungileyo kunye nezibi.

5) Indawo yeflash ephezulu, ukhuseleko olulungileyo, ixabiso eliphantsi,-elingenatyhefu kwaye{2}}lingangcolisi.

Izinyibilikisi eziqhelekileyo eziphilayo ezisetyenziswa kwi-lithium -i-electrolyte yebhetri yeion zahlulwe ikakhulu kwizinyibilikisi zecarbonate kunye nezinyibilikisi ze-organic ether, njengoko kubonisiwe kuMfanekiso 7{2}}6. Ukufumana ukusebenza okuphezulu - kwe-electrolyte yebhetri ye-lithium-ion, isinyibilikisi esixubeneyo esiqulethe izinyibilikisi ezimbini okanye ngaphezulu ze-organic ngokuqhelekileyo sisetyenziswa, esibavumela ukuba bancedisane kwaye bafezekise ukusebenza kakuhle ngokubanzi. Iimpawu ezibonakalayo ze-carbonate solvents eziqhelekileyo ziboniswa kwiThebhile 7-1.

Itheyibhile 7-1 iiPropati zoMzimba zeZinyibilikisi zeCarbonate eziqhelekileyo

Izinyibilikisi ze-ether ze-Organic ziquka i-ethers ze-chain ezifana ne-1,2 - i-dimethoxypropane (DMP), i-dimethoxymethane (DMM), kunye ne-ethylene glycol dimethyl ether (DME), kunye ne-ethers ye-cyclic efana ne-tetrahydrofuran (THF) kunye ne-2 - i-methyltetra-Methyl-furan (2-). Kwizinyibilikisi ze-ether chain, ixesha elide i-carbon chain, ngcono ukuzinza kweekhemikhali, kodwa iphezulu i-viscosity kunye nezantsi izinga lokufuduka kwe-lithium-ion. I-Ethylene glycol dimethyl ether inokwenza i-chelate ezinzileyo (LiPF6 · DME) kunye ne-lithium hexafluorophosphate, ebonisa amandla anamandla okunyibilika kwiityuwa ze-lithium kunye nesiphumo esiphezulu se-electrolyte conductivity. Nangona kunjalo, i-DME inozinzo olubi lweekhemikhali kwaye ayikwazi ukwenza ifilimu ezinzileyo ye-passivation kumphezulu wezinto ezimbi ze-electrode.

Izinyibilikisi zeCarbonate ziquka i-cyclic carbonates ezifana nepropylene carbonate (PC) kunye ne-ethylene carbonate (EC), kunye ne-carbonates ye-chain ezifana ne-dimethyl carbonate (DMC), i-diethyl carbonate (DEC), kunye ne-methyl ethyl carbonate (EMC). I-Cyclic carbonates ine-dielectric engaguqukiyo ephezulu, yenza ukuba iityuwa ze-lithium zinyibilike ngakumbi, kodwa zine-viscosity ephezulu, ekhokelela kwizinga elisezantsi le-lithium -yezinga lokufuduka kwe-ion. I-Chain carbonates ine-dielectric ephantsi kunye ne-lithium ebuthathaka yokunyibilika kwetyuwa, kodwa i-viscosity ephantsi kunye nokuhamba kakuhle, iququzelela ukufuduka kwe-lithium -.

Iindidi zedangatye{0}}zongezo ezirhabaxa ze-lithium{1}}i-electrolyte ze-ion zibonisiwe kuMfanekiso 7-}7. Izongezo, ezisetyenziswe kwiimali ezincinci, zineempembelelo ezibalulekileyo kwaye ziyindlela yoqoqosho kunye nesebenzayo yokuphucula ukusebenza kweebhetri ze-lithium - ze-ion. Ngokudibanisa idosi encinci yezongezo kwi-electrolyte ye-lithium -ibhetri ze-ion, iimpawu ezithile zokusebenza kwebhetri zingaphuculwa ngokukodwa, ezifana nomthamo obuyiselwa umva, ukuhambelana kwe-electrode/electrolyte, ukusebenza komjikelo, ukusebenza komgangatho, kunye nokusebenza kokhuseleko, ukudlala indima ebalulekileyo kwiibhetri ze-lithium{8}}. I-lithium-ion ibhetri ye-electrolyte yokongeza ifanele ibe nezi mpawu zilandelayo:

1) Ukunyibilika okuphezulu kwi-solvents eziphilayo.

2) Imali encinci inokuphucula kakhulu enye okanye ngaphezulu kweempawu zokusebenza.

3) Akukho zimpendulo ezinobungozi kunye nezinye izinto zebhetri ezichaphazela ukusebenza kwebhetri.

4) Ixabiso eliphantsi,-ayiyotyhefu okanye ityhefu ephantsi.

Ngokusekwe kumsebenzi wazo, izongezo zingahlelwa ngokwezongezo zokuqhuba, izongezo zokukhusela umrhumo ogqithisileyo, izongezo ze-flame retardant, ifilimu ye-SEI{0}}ezenza izongezo, izikhuseli zezinto ze-cathode, izizinzi ze-LiPF6, kunye nezinye izongezo ezisebenzayo.

Izongezo eziqhubayo ziphucula ukusebenza kwesantya seebhetri ze-lithium -ngokulungelelaniswa nee-ion ze-electrolyte, ukukhuthaza ukunyibilika kwetyuwa ye-lithium, kunye nokwandisa i-electrolyte conductivity. Ngenxa yokuba izongezo ze-conductive zisebenza ngokuphendula kolungelelwaniso, zikwabizwa ngokuba izongezo ze-ligand, kwaye zihlelwa kwii-anionic ligands, i-cationic ligands, kunye ne-neutral ligands esekelwe kwi-ion esebenzisanayo.

Izongezo zokukhusela umrhumo ogqithileyo zibonelela ngokhuseleko lomrhumo ogqithisileyo okanye ziphucula ukunyamezeleka komrhumo. Ziye zahlelwa ngokusebenzayo kwizongezo ze-redox kunye nezongezo ze-monomer. Okwangoku, izongezo ze-redox ubukhulu becala luchungechunge lwe-anisole, olunamandla aphezulu e-redox kunye nokunyibilika okulungileyo. Izongezo ze-Monomer zingena kwi-polymerization reactions phantsi kombane ophezulu, ukukhupha iigesi, kunye ne-polymer coat the surface material cathode, ephazamisa ukutshaja. Izongezo ze-Monomer ikakhulu ziquka iikhompawundi ezinuka kamnandi ezifana nexylene kunye nephenylcyclohexane.

Izongezo ze-flame retardant zisebenza ngokuphakamisa indawo yokutshisa i-electrolyte okanye ukuphelisa ukusabela kwe-radical chain yamahhala evimbela ukutsha. Iindidi zabo ziboniswe kuMfanekiso 7-8. Ukongeza i-flame retardants yenye yeendlela ezibalulekileyo zokunciphisa ukutsha kwe-electrolyte, ukwandisa ubushushu bokusebenza kweebhetri ze-lithium-ion, kunye nokuphucula ukusebenza kwazo. Iindlela zokusebenza zezongezo ezibuyisela idangatye ikakhulu zimbini:

I-1) Ngokudala i-insulating layer phakathi kwesigaba segesi kunye nesigaba esincitshisiweyo, banqanda ukutshisa kwi-condensed and gas phase.

I-2) Babamba ii-radicals zamahhala ngexesha lenkqubo yokuphendula ukutsha, ukuphelisa i-radical chain reaction yamahhala evimbela ukutshiswa kokutsha phakathi kwezigaba zegesi.