Bulging (tseem hu ua o) yog ib qho tshwm sim tshwm sim hauv lithium roj teeb tsis ua haujlwm, ua rau muaj kev phom sij rau kev nyab xeeb (xws li hluav taws kub lossis tawg), thiab feem ntau yuav tsum tsis txhob siv tam sim ntawd.
Lub ntsiab lus ntawm bulging yog tsim cov roj ntau dhau hauv lub roj teeb, ua rau muaj zog ntxiv thiab deformation ntawm cov casing lossis cov hlwb sab hauv. Qhov no tshwm sim nyob rau hauv hnab roj teeb. Kev tsim cov pa roj me ntsis hauv cov roj teeb prismatic tuaj yeem ua rau lub roj teeb tsis zoo, thiab qhov xwm txheej hnyav, tuaj yeem ua rau tawg - pov thawj valve qhib.
Cov laj thawj ntawm cov roj teeb bulging muaj xws li:
I. Cov tshuaj tiv thaiv sab hauv tsim cov pa roj (hauv paus ua rau)
1.1 Electrolyte decomposition
Overcharge:Thaum qhov hluav taws xob siab dhau lawm, cov khoom siv hluav taws xob zoo electrode yuav tsis ruaj khov, tso tawm cov pa oxygen, uas cuam tshuam nrog cov electrolyte, ua kom muaj cua sov thiab roj ntau (xws li CO₂, CO).
Siab - qhov kub thiab txias:Organic kuab tshuaj nyob rau hauv cov electrolyte (xws li carbonates) yooj yim decompose thiab tsim roj thaum kub kub.
1.2 SEI zaj duab xis decomposition thiab regeneration
Thaum caij tsheb kauj vab, cov khoom siv electrolyte interface (SEI zaj duab xis) ntawm qhov tsis zoo electrode nto yuav kho nws tus kheej me ntsis, siv cov electrolyte thiab tsim cov roj me me. Nyob rau hauv overcharging los yog kub kub, SEI zaj duab xis decomposes ho, nthuav tawm qhov tsis zoo electrode (xws li, graphite) uas reacts nrog cov electrolyte los tsim hydrogen thiab alkane gases.
1.3 Moisture Impurity Reaction
Yog hais tias ya raws tau qhia thaum lub sij hawm tsim khoom, lithium ntsev nyob rau hauv cov electrolyte (xws li, LiPF₆) yuav hnov mob nrog dej los tsim HF (corrosive) thiab hydrogen, ua rau o thiab cov khoom puas.
1.4 Tsis zoo Electrode Lithium Plating
Thaum lub sij hawm qis - kub them, siab- tam sim no them, lossis tsis zoo electrode aging, lithium ions yuav raug txo ncaj qha rau cov hlau lithium ntawm qhov tsis zoo electrode nto (lithium plating) es tsis txhob embedding nyob rau hauv graphite txheej.
Nws yog xim hlau lithium reacts nrog cov electrolyte los tsim cov pa roj xws li hydrogen, thiab kuj tseem tuaj yeem ua rau cov khoom sib cais, ua rau luv luv.
Cov saum toj no piav qhia txog cov laj thawj vim li cas cov roj teeb bulge, uas yog cov laj thawj tseem ceeb (mechanisms) ntawm kev tsim roj. Kev tsim roj av yog yam tsis muaj kev zam; Txawm tias muaj kev tsim zoo meej, kev xaiv cov khoom siv zoo tshaj plaws, thiab cov txheej txheem tsim kom zoo, cov roj teeb yuav tsim cov roj. Cov roj av tau txais txiaj ntsig tau, thiab lub roj teeb qhov chaw sab hauv tuaj yeem ua raws li lawv.
Txawm li cas los xij, kev tsim tsis tsim nyog thiab kev tsim khoom tsis raug tuaj yeem ua kom muaj roj av, thiab kev siv roj teeb tsis raug yuav ua rau kom muaj roj ntau ntxiv. Cov hauv qab no feem ntau qhia txog cov teeb meem tsim hluav taws xob los ntawm cov xwm txheej no;
II. Tsim thiab tsim khoom tsis raug
2.1 Cov txheej txheem ntau lawm
Kev tswj tsis zoo ntawm cov av noo nyob rau hauv qhov chaw tsim khoom ua rau cov dej noo ntau dhau hauv cov roj teeb ntawm tes.
Cov txheej txheem electrode tsis sib xws thiab qhov tsis sib xws ntawm winding/stacking tuaj yeem ua rau muaj kev ntxhov siab hauv cheeb tsam lossis luv luv -kev pheej hmoo ntawm Circuit Court.
ACEY-HFC250electrode txheej tshuabyog dav siv nyob rau hauv kev tshawb fawb ntawm ntau yam siab - kub txheej films, xws li ceramics, crystalline lug, roj teeb cov ntaub ntawv, thiab tshwj xeeb nanomaterials.
Tsis zoo encapsulation ua rau roj to lossis sealing tsis zoo.
2.2 Khoom Defects (Separator)
Tsis zoo (tsis sib xws porosity, tsis tshua muaj zog txhua yam) ua rau nws yooj yim rau shrinkage los yog tearing.
Kev tsim cov tshuaj electrolyte tsis raug ua rau cov yeeb yaj kiab tsis zoo- tsim cov khoom.
2.3 Kev nyab xeeb valve tsis ua haujlwm
Qee cov mos- pob lossis cylindrical roj teeb muaj cov qauv tsim tsis zoo uas tsis tuaj yeem tso siab rau lub sijhawm thaum nws nce.
III. Cov xwm txheej siv tsis raug (Common Causes)
3.1 Kev them nyiaj ntau dhau / tso tawm
Overcharge:Cov qauv zoo electrode collapses, ua oxygen thiab ua kom cov electrolyte decomposition.
Tshaj- tawm (tsawg voltage):Cov khoom siv tooj liab tam sim no ntawm qhov tsis zoo electrode dissolves, ua rau luv luv Circuit Court thiab roj ntau lawm.
3.2 Siab -Tsub Ib puag ncig
Ntev raug rau qhov kub thiab txias (xws li lub hnub ncaj qha lossis kub kub hauv lub tsheb) ua rau muaj qhov nce ntxiv ntawm qhov tshwm sim ntawm sab.
Siab -tam sim no them thiab tso tawm ua rau muaj cua sov sab hauv.
3.3 Mechanical puas
Squeezing, puncture, los yog poob tuaj yeem ua rau cov qauv hauv lub cev tsis zoo, ua rau micro- circuits luv lossis electrolyte to.
3.4 Ntev -Lub Sijhawm Tsis Muaj Chaw Cia
Kev khaws cia lub roj teeb rau lub sijhawm ntev ntawm qhov siab tshaj lossis qis qis ua rau muaj kev cuam tshuam sab nraud txuas ntxiv musmaj mam, maj mam ua roj.