Isishwankathelo sokuHlalutywa kweFail kunye neFault Mechanism yeLithium Ion ibhetri

Umbhali :Iflowpower-UMboneleli weSikhululo saMandla esiphathwayo

Isizukulwana kunye nokukhula kwefilimu ye-1SEI ikwinkqubo yebhetri ye-lithium-ion yorhwebo, kwaye inxalenye yokulahlekelwa kwamandla ebhetri ivela kwimpembelelo yecala phakathi kwegraphite kunye ne-organic electrolyte, kwaye i-graphite iphendulwa ngokulula nge-electrochemically nge-lithium ion organic electrolyte, ngakumbi i-Solvent. yivinyl carbonate (EC) kunye ne-dimethyl carbonate (DMC). Xa ibhetri ye-lithium ion ikwixesha lokuqala lokutshaja (inqanaba), i-electrolyte engalunganga kunye ne-lithium ion electrolyte yenzeka kwaye i-lithium ion electrolyte yenzeka kwaye umaleko wojongano oluluqilima lwe-electrolyte (SEI) ifilimu yenziwa kumphezulu wegraphite, onokubangela inxalenye yomthamo ongenakuguqulwa. Ifilimu ye-SEI iqinisekisa ukuhanjiswa kwee-ion ngelixa ikhusela i-substance esebenzayo, kwaye ikhusela ukuzinza kokusebenza kwezinto ezisebenzayo zebhetri esebenzayo ngelixa likhusela into esebenzayo.

Nangona kunjalo, ngexesha lomjikelo olandelayo webhetri, ekubeni ukwandiswa rhoqo kunye nokucuthwa kwezinto ze-electrode kubangela ukuba indawo entsha esebenzayo iveze, oku kunokubangela ukusilela okuqhubekayo kwelahleko, oko kukuthi, umthamo webhetri uhla ngokuqhubekayo. Le ndlela yokungaphumeleli inokuthi ifakwe kwinkqubo yokunciphisa i-electrochemical ebusweni be-electrode, ebonakaliswa njengokunyuka okuqhubekayo kobunzima befilimu ye-SEI. Ngoko ke, ukufundwa kweefilimu ze-SEI zeekhemikhali zamacandelo kunye ne-morphology ingaba nzulu ngakumbi, imbangela yebhetri ye-lithium-ion kunye nokuncipha kwamandla.

Inkqubo yokwenziwa kwefilimu ye-SEI Kwiminyaka yakutshanje, abaphandi baye bazama ukufunda ubume beembrane ze-SEI ngokudiliza iimvavanyo zeenkqubo ezincinci zebhetri. Inkqubo yokuqhaqha ibhetri iqhutyelwa kwibhokisi yeglavu yegesi ye-aerosolic (<5 ppm). After the battery is disassembled, it can pass a nuclear magnetic resonance technology (NMR), a flight time secondary ion mass spectrometry (TEMS), a scanning electron microscope (SEM), a transmission electron microscope (TEM), an atomic force microscope (AFM), X-ray absorption spectrum (XAF), and Infrared (FTIR) and Raman Spectroscopy and other test methods study the thickness, morphology, composition, growth process and mechanism of SEI membranes.

Nangona iindlela ezininzi zokuvavanya zisetyenziselwe ukubonakalisa ifilimu ye-SEI, imodeli yangempela yefilimu ye-SEI ikhula kwibhetri isetyenziselwa ukubonakalisa iindlela eziphambili kunye nezithe ngqo. Ubunzima kukuba ifilimu ye-SEI iyinkimbinkimbi kunye nezinto ezahlukeneyo ezifana ne-organic and inorganic, kwaye isithako sinzima, kwaye sinobuthathaka kakhulu kwaye kulula ukuphendula kwindalo. Ukuba ayifanelekanga, kunzima ukufumana ulwazi oluyinyani lwefilimu ye-SEI.

Ukuqina kwefilimu ye-SEI yindlela eqhelekileyo ye-electrochemical parasitic side reaction, enobudlelwane obusondeleyo kunye ne-reaction kinetics, inkqubo yokudlulisa ubunzima, kunye nejometri yesakhiwo sebhetri. Nangona kunjalo, utshintsho lwefilimu ye-SEI alukhokeleli ngokuthe ngqo ekungaphumelelini kokutshabalalisa, kwaye ukubola kwayo kuya kubangela ukunyuka kobushushu bangaphakathi bebhetri, nto leyo inokubangela ukubola kwegesi, kunye nobushushu obunzima kuya kubangela ukushisa. ayilawuleki. Kwi-FMMEA, ukubunjwa kunye nokukhula kwefilimu ye-SEI kuthathwa njengendlela yokulahlekelwa, enokubangela ukuba ibhetri inciphise umthamo kunye nokwandisa i-impedance yangaphakathi.

I-2 ye-lithium dendrites ivelisa, ukuba ibhetri ihlawuliswa ngokukhawuleza kwi-inxinano yangoku ephezulu kunokulinganisa kwayo ngoku, kwaye indawo engafanelekanga yenziwa lula ukwenza i-metal lithium dendride. Le kristale ye-dendritic kulula ukugqobhoza i-diaphragm, ibangela isiphaluka esifutshane ngaphakathi kwebhetri. Le meko inokubangela ukusilela ekutshatyalalisweni kwebhetri, kwaye kunzima ukuyibhaqa phambi kokuba ibhetri ibemfutshane.

Kwiminyaka yakutshanje, abaphandi baye bafunda izinga lokukhula kwe-lithium dendride kunye nobudlelwane phakathi kwezinga lokukhula kwe-lithium dendrites kunye ne-lithium ion diffusion umthamo we-lithium dendrites. Iimvavanyo zibonisa ukuba ukukhula kwe-lithium delegra kunzima ukukubona okanye ukujonga kwinkqubo epheleleyo yebhetri, kwaye imodeli yangoku inqunyelwe ekukhuleni kwe-lithium dendrites phantsi kwenkqubo enye. Kwinkqubo yovavanyo, ibhetri ecacileyo eyakhiwe ngeglasi yequartz inokubona inkqubo yokukhula kwe-lithium dendrites in situ.

Umphandi weZhang Yuegono eSuzhou Nanotechnology kunye neNano Bionic Research Institute kwilizwe lam uye wabonisa inkqubo yokwenziwa kwe-lithium dendrites (njengoko kuboniswe ngevidiyo) iteknoloji kwi-teknoloji ye-electron microscope (SEM) yokuskena. Nangona kunjalo, kwinkqubo yebhetri ye-lithium-ion yorhwebo, kunzima ukufezekisa ukubonwa kwasekuqaleni kwamasebe e-lithium. Imeko yendalo yonke kukuqwalasela iikristale zesebe le-lithium ngokudiliza ibhetri.

Nangona kunjalo, ngenxa yokuba umsebenzi wesebe le-lithium uphezulu kakhulu, kunzima ukuhlalutya iinkcukacha zesizukulwana. Zier et al. Kucetywa ukuzoba i-electrode electron micrograms ngokudaya isakhiwo se-electrode ukumisela indawo yee-dendrites.

Ukuba ngaphambi kokuchithwa kwebhetri, isizukulwana se-lithium branch crystal sibangele ngaphakathi kwisiphaluka esifutshane ngaphakathi, ngoko le nxalenye yekristal ye-dendritic inokuba nzima ukuyiqwalasela ngenxa yokuba i-pulse yangoku yesiphaluka esifutshane sangaphakathi inokubangela ukuba i-lithium branch crystallization. Ukuvalwa kwendawo ye-microporous ye-diaphragm icebisa ukuba indawo enokwenzeka yokukhula ye-lithium dendrites, kodwa ezi ndawo zinokuthi zigqithise ngokuyinxenye okanye zibangelwa ukungcola kwesinyithi. Ke ngoko, uphuhliso olongezelelweyo lweemodeli zokungaphumeleli ukuqikelela ukuvela kwamasebe e-lithium, kwaye kwangaxeshanye, kunentsingiselo enkulu yokufunda ubomi kunye nobudlelwane bokungaphumeleli phantsi kweemeko ezahlukeneyo zokusebenza.

I-3 I-polllization yezinto eziphathekayo ezisebenzayo azilingani ekuhanjisweni kwentlawulo ekhawulezayo kunye nokukhutshwa okanye i-electrode esebenzayo, into esebenzayo ixhomekeke kwipowder okanye ukuhlukana. Ngokuqhelekileyo, njengoko ibhetri isandisiwe, iincinci ze-micron-size, uxinzelelo lwangaphakathi lwe-ion lunokwaphulwa. Ukuqhekeka kokuqala kunokubonwa yi-SEM kumphezulu wezinto eziphathekayo ezisebenzayo.

Njengoko ukubethelwa ngokuphindaphindiweyo kwe-lithium ion, ii-cracks zihlala zikhula, okubangela ukuba iinqununu ziqhekeke. Iingqungquthela eziqhekezayo ziya kuveza indawo entsha esebenzayo, kwaye ifilimu ye-SEI iveliswa kwindawo entsha. Ngophando kunye nohlalutyo lwe-lithium ion yokufaka uxinzelelo, uyilo olungcono lwezixhobo ze-electrode zebhetri.

Christensen kunye noNewman et al. Kuphuhliswe imodeli yokuqala yoxinzelelo lwe-lithium-ion, kunye nabanye abaphandi baye bandisa izinto ezahlukeneyo, kunye ne-geometric morphology yezinto eziphathekayo, kunye nezixhobo. Imodeli yoxinzelelo efakwe kwi-Ion iya kunceda abaphandi ukuba bayile izinto ezisebenzayo ngakumbi.

Nangona kunjalo, ukulahlekelwa kwamandla kunye namandla eengqungquthela zezinto ezisebenzayo kuqhutyelwa phambili, kwaye indlela yokungaphumeleli yokuhlukana kweengqungquthela iqikelelwe ngokubanzi ukuqikelela ubomi beebhetri ze-lithium-ion. Ukutshintshwa komthamo wezinto ze-electrode kunokubangela ukuba into esebenzayo ikhutshwe kunye nomqokeleli wangoku, ukwenzela ukuba le nxalenye yento esebenzayo ayifumaneki. Inkqubo ye-lithium ye-inconed yezinto ezisebenzayo ihamba kunye nokufuduka kwe-ion kunye nokufuduka kwe-electron yangaphandle ngaphakathi kwebhetri.

Ekubeni i-electrolyte ifakwe kwi-electronic insulated, i-ion kuphela inokubonelelwa kuphela. Ukuziphatha kwee-electron kubalulekile kuthungelwano lwe-conductive olwakhiwe yi-electrode surface yi-agent conductive. Ukutshintsha rhoqo kumthamo wezinto ze-electrode kunokubangela ukuba kubekho izinto ezisebenzayo ezisuka kwinethiwekhi yokuqhuba ukwenza inkqubo yodwa, engafumanekiyo.

Olu tshintsho kwisakhiwo se-electrode sinokulinganiswa ngokulinganisa indlela efana ne-porosity okanye indawo ethile. Le nkqubo inokugaywa ngokugaya umphezulu we-electrode usebenzisa i-ion beam (FIB), usebenzisa i-SEM ukwenza i-morphological observation okanye i-X-ray tomography test usebenzisa i-SEM. Izinto ze-electrode ze-Si zihlanjululwe kwaye zikhutshwe kwi-conductor network.

I-electrode esebenzayo ye-electrode esebenzayo ye-electrode esebenzayo yinto eninzi ye-transition metal oxide, njenge-lithium cobaltate (LiMn2O4), okanye i-polyanate Lithium ityuwa, i-lithium iron phosphate (LifePo4). Uninzi lwezinto ezisebenzayo ezisebenzayo ziindlela zokusabela ezizinzisiweyo, kwaye iindlela zabo zoxinzelelo kunye neendlela zokudodobala koqoqosho ikakhulu ngenxa yokuwa kweegranules kunye nenkcazo yezinto ezisebenzayo apha ngasentla. Ifilimu ye-SEI iphinda yenziwe kwaye ichaphazeleke kumphezulu we-electrode efanelekileyo, kodwa indawo ye-electrode efanelekileyo inamandla aphezulu, kwaye ifilimu yayo ye-SEI incinci kakhulu kwaye izinzile.

Ukongeza, izinto ezintle ze-electrode nazo zichaphazeleka kwimpembelelo yokuvelisa ukushisa kwangaphakathi, ngakumbi xa ibhetri ingaphezulu. Ngexesha lokuhlawula, i-electrolyte iyancipha phantsi koxinzelelo oluphezulu, nto leyo ebangela ukuba i-electrolyte kunye ne-electrode esebenzayo isebenze, ebangela ukuba ukushisa kwangaphakathi kwebhetri kuqhubeke nokunyuka, kunye nezinto eziphathekayo ze-electrode zikhupha i-oksijini. Ukuphucula ngakumbi, okukhokelela ekuphumeni kwe-thermal kulawulo, kuya kubangela ukusilela kokutshatyalaliswa kwibhetri.

Izinto ezilungileyo ze-electrode ezenzeka ngexesha lokutshaja kwangaphambili zingahlalutywa nge-chromatography yegesi ukuhlalutya okanye ukufumanisa isakhiwo sezinto ze-electrode nge-X-ray spectrum discovery electrode structure. Nangona kunjalo, okwangoku akukho modeli yokungaphumeleli enokuthi iqikelele ngaphakathi kwebhetri ngokuphuphuma kwegesi egcwele kakhulu. Isishwankathelo: Imowudi yokungaphumeleli kwebhetri ye-lithium-ion ibhetri ebonakalayo kunye ne-electrode engafanelekanga ibalulekile ekuboleni kwe-membrane ye-SEI, ukuveliswa kwe-lithium enikezelwe i-crystal okanye i-crystals ye-copperprine, umgubo wezinto ezisebenzayo kunye negesi yokubola ubushushu, njl.

Phakathi kwabo, isizukulwana se-lithium derivatives okanye i-copper delegths, i-gas yokubola kwezinto eziphathekayo ibangelwa lula yi-thermal ngaphandle kolawulo lweseli, ebangela ukutsha kwebhetri, kunye nokuqhuma. Ukungaphumeleli kweebhetri ze-lithium-ion kuhlalutywa yimodi ephelileyo, kwaye umatshini uphuculwe ngokulungisa izinto zebhetri, ukwakheka, kunye nokuphucula ukulungelelaniswa kwendalo, ukuthembeka kunye nokhuseleko lwebhetri. Ke ngoko, kukho isikhokelo esibaluleke kakhulu sokubaluleka kwemveliso kunye nokusetyenziswa okusebenzayo kwebhetri.