1. Mechanism ntawm thermal runaway txheej txheem nyob rau hauv lithium-ion roj teeb
Cov roj teeb lithium yog tsim los ntawm embedding lithium ions rau hauv cov pa roj carbon (petroleum coke thiab graphite) los tsim cov electrode tsis zoo. LixCoO2 feem ntau yog siv los ua cov khoom siv hluav taws xob zoo, thaum LixNiO2 thiab LixMnO4 kuj tseem siv. LiPF6+diethylene carbonate (EC) + dimethyl carbonate (DMC) yog siv los ua cov electrolyte. Lub ntsiab ua rau thermal runaway muaj xws li txhua yam kev puas tsuaj, overcharging, nyob rau hauv luv luv circuits, thiab lwm yam. Nyob rau hauv lub cuam tshuam ntawm ntau yam, cov active cov ntaub ntawv nyob rau hauv lithium-ion roj teeb muaj kev kub ntxhov exothermic tshua, thiab nyob rau hauv lub kub ntawm lub roj teeb nyob rau hauv lub controllable ntau yam. , thaum kawg ua rau thermal runaway. Cov tshuaj tiv thaiv exothermic tshwm sim hauv lub lithium-ion roj teeb suav nrog kev puas tsuaj ntawm cov khoom electrolyte interface lub ntsej muag daim npog ntsej muag SEI, cov tshuaj tiv thaiv ntawm cov khoom siv tsis zoo thiab cov electrolyte, cov tshuaj tiv thaiv ntawm cov khoom siv tsis zoo thiab cov ntaub qhwv, thiab cov tshuaj tiv thaiv oxidation decomposition. ntawm electrolyte.
Thaum lub sij hawm them thiab tso tawm cov txheej txheem ntawm lithium-ion roj teeb, vinyl carbonate ntawm cov khoom-theem cuam tshuam ntawm cov khoom siv hluav taws xob yuav hnov mob nrog cov tsis zoo electrode lithium, tsim ib txheej ntawm SEI zaj duab xis ntawm graphite adhesion nto. Cov membrane no tuaj yeem ua rau qeeb qeeb lossis txawm tias tiv thaiv cov tshuaj tiv thaiv ntawm cov electrolyte thiab cov khoom nquag ntawm ob sab ntawm cov electrode, txo nws cov exothermic tus nqi thiab txhim kho kev ruaj ntseg ntawm cov khoom zoo thiab tsis zoo electrode.
Raws li qhov kub nce mus rau 90-120 degree, SEI zaj duab xis pib decompose, ua raws li cov tshuaj tiv thaiv exothermic ntawm cov electrolyte thiab cov khoom siv tsis zoo electrode. Noj vinyl carbonate ua piv txwv, cov txheej txheem tshuaj tiv thaiv tau qhia hauv qhov sib npaug (1) thiab (2):
Thaum lub sij hawm exothermic cov tshuaj tiv thaiv, lub internal kub ntawm lub roj teeb maj mam nce. Raws li kev siv cov khoom sib txawv diaphragm, lawv cov ntsiab lus melting kuj txawv. Feem ntau cov polypropylene diaphragm muaj qhov melting point ntawm 165 degree thiab cov khoom siv polyethylene muaj qhov melting point ntawm 135 degree. Tom qab ncav cuag lub melting point kub ntawm cov khoom separator, lub internal separator undergoes lub zos contraction, ua rau ncaj qha kev sib cuag ntawm qhov zoo thiab tsis zoo electrode cov ntaub ntawv nyob rau hauv lub roj teeb, ua rau ib tug luv luv Circuit Court thiab tsim ib tug loj npaum li cas ntawm tshav kub. Qhov loj ntawm cov cua sov uas tsim los ntawm luv luv Circuit Court ua rau lub diaphragm mus rau daim ntawv cog lus sai, ntxiv exothermic cov tshuaj tiv thaiv.
Nyob rau tib lub sij hawm, nyob rau hauv qhov kub thiab txias qhov twg SEI zaj duab xis decomposes thiab undergoes exothermic cov tshuaj tiv thaiv, lithium ntsev kuj raug mob hnyav exothermic tshua nrog cov electrolyte. Cov khoom siv nquag siv rau cov roj teeb lithium-ion muaj xws li lithium hexafluorophosphate (LiPF6), lithium tetrafluoroborate (LiBF4), thiab lwm yam. Lithium hexafluorophosphate decomposes ntawm qhov kub thiab txias los tsim PF5, uas ntxiv reacts nrog cov kuab tshuaj mus nqa cov pa atoms ntawm CO. daim ntawv cog lus thiab undergo ib tug nruj exothermic tshuaj tiv thaiv, ntxiv accelerating lub decomposition ntawm electrolyte. Tib lub sijhawm, oxidation-txo cov tshuaj tiv thaiv ntawm lithium hexafluorophosphate thiab hnyav kuj tso tawm cov pa roj hydrofluoric acid (HF). Cov txheej txheem tshuaj tiv thaiv tshwj xeeb tau qhia hauv qhov sib npaug (3) txog (5):
Nyob rau hauv tib qhov kub thiab txias, cov electrolyte nws tus kheej tau txais cov tshuaj tiv thaiv decomposition thiab tso tawm ib qho me me ntawm cov pa roj. Thaum siv tus nqi calorimetry los txheeb xyuas cov txheej txheem thermal khiav, nws tau pom tias cov roj hluav taws xob tsim los ntawm electrolyte decomposition yog tsim los ntawm C2H4, CO, thiab H2. Cov electrolyte yog vaporized sai thiab ua rau lub siab sab hauv ntawm lub roj teeb. Thaum lub siab sab hauv mus txog qhov kev txwv ntawm lub siab nyem valve, ntau cov roj combustible yuav raug ejected, ntxiv exacerbating kev sib kis ntawm thermal runaway. Cov cua sov uas tsim los ntawm kev ua kom tiav ntawm electrolyte yog ntau dua li cov cua sov tso tawm los ntawm cov tshuaj tiv thaiv decomposition. Noj ethylene carbonate (EC) thiab propylene carbonate (PC) ua piv txwv, cov txheej txheem tshuaj tiv thaiv ntawm electrolyte oxidation (6) ~ (7) thiab tsis tiav oxidation (8) ~ (9) yog raws li nram no:
Raws li qhov kub thiab txias ntawm lub roj teeb maj mam nce, cov khoom siv ntawm qhov zoo electrode pib decompose. Raws li kev siv cov khoom siv sib txawv, qhov kub ntawm qhov kev tawm tsam exothermic kuj txawv. Lub decomposition ntawm qhov zoo electrode active khoom tsim oxygen, uas tom qab ntawd koom nrog cov tshuaj tiv thaiv nrog cov khoom siv sab hauv, tsim cov roj ntau hauv lub roj teeb. Cov txheej txheem tshuaj tiv thaiv yog raws li nram no:
Thaum qhov kub siab tshaj 136 degree, lub binder polyvinylidene fluoride (PVDF) yuav hnov mob nrog lithium los tsim cov roj hydrogen. Cov txheej txheem tshuaj tiv thaiv yog raws li nram no:
Tsuas yog SEI zaj duab xis melting thiab absorbing tshav kub, cov tshuaj tiv thaiv saum toj no yog tag nrho cov exothermic tshua. Thaum tshav kub kub tso tawm ntawm electrolyte decomposition, cais, roj teeb cov khoom siv, thiab cov nplaum tso nyiaj rau 43.5%, 30.3%, 20.1%, thiab 6.2% ntawm tag nrho cov cua sov tso tawm, feem. Cov tshuaj tiv thaiv ntawm cov khoom siv zoo thiab tsis zoo ntawm lub roj teeb thiab cov electrolyte yog qhov kub tshaj plaws.
2. Inducing yam ntawm thermal runaway nyob rau hauv lithium-ion roj teeb
Cov teeb meem tshwm sim ntawm thermal runaway nyob rau hauv lithium-ion roj teeb tuaj yeem muab faib ua peb pawg: kev tsim txom txhua yam (kab koob puncture, compression deformation, sab nraud kev sib tsoo), hluav taws xob tsim hluav taws xob (overcharge thiab tshaj tawm, luv luv Circuit Court), thiab thermal quab yuam (tso tswj qhov system. ua tsis tiav). Kev tsim txom txhua yam tuaj yeem yooj yim induces sab hauv luv luv hauv cov roj teeb lithium, ua rau thermal runaway; Nyob rau hauv kev tsim txom ntawm hluav taws xob, overcharging thiab tso tawm ntawm cov roj teeb tuaj yeem ua rau muaj kev cuam tshuam sab hauv, ua rau lub zos overheating ntawm cov roj teeb hlwb thiab ua rau thermal runaway; Sab nraud luv luv Circuit Court yog lub xeev txaus ntshai ntawm kev tso tawm sai ntawm cov roj teeb, qhov uas tsis tshua muaj siab tam sim no ua rau kub ceev thiab txawm tias fuse lub roj teeb terminals; Nyob rau hauv lub xeev ntawm thermal tsim txom, tsis ua hauj lwm ntawm lub thermal tswj system feem ntau ua rau lub contraction thiab decomposition ntawm sab hauv diaphragm, thaum kawg ua rau sab hauv luv circuits thiab thermal runaway.
Tsis tas li ntawd, lub roj teeb tus kheej lub xeev kuj yog ib qho tseem ceeb ua rau thermal runaway. Nrog rau kev nce ntawm cov roj teeb them thiab tawm mus thiab qhov induction ntawm impurities sib xyaw thaum lub sij hawm dendrite ntau lawm, cov kev phiv tshwm sim xws li hlau dendrites yog generated, uas yog ib qho yooj yim rau tho lub separator thiab ua rau lub zos luv luv Circuit Court nyob rau hauv lub roj teeb.
2.1 Kev tshawb fawb txog roj teeb thermal khiav tawm los ntawm kev tsim txom thermal
Raws li cov electrochemical thermal coupling overcharge tshav kub khiav qauv ntawm lithium-ion roj teeb tsim nyob rau hauv cov ntaub ntawv, lithium-ion roj teeb feem ntau pib nws tus kheej thaum kub txog 80 degree. Thaum lub roj teeb kub dhau lawm thiab tsis tuaj yeem tso tawm tau zoo, kev tswj xyuas thermal ntawm lub roj teeb yuav ua rau lub roj teeb kub tsis txaus, uas yuav cuam tshuam los ntawm cov neeg hauv zos mus rau lub hwj chim roj teeb pob, ua rau muaj kev cuam tshuam sab nraud thiab thermal runaway.
Kev tsim txom thermal tsis tshwm sim nyob rau hauv lub roj teeb. Feem ntau, vim yog kev tsim txom los yog lwm yam laj thawj, qhov kub thiab txias ntawm lub roj teeb tau nce mus rau qhov pib, thiab cov cheeb tsam hauv cheeb tsam ntawm lub roj teeb tau ua kom sov, ua rau muaj kev tsim txom thermal thiab ua rau muaj kev kub ntxhov thiab tiv thaiv tus kheej ntawm lub roj teeb.
Nyob rau tib lub sijhawm, thermal runaway kuj tau siv los ua ib txoj hauv kev tshawb fawb rau kev sim cov txheej txheem roj teeb khiav tawm thiab kuaj xyuas cov yam ntxwv kev nyab xeeb thaum lub roj teeb thermal runaway. Xyoo 1999, KITOH et al. ua kev tshawb fawb txog kev saib xyuas cov thermal runaway kev nyab xeeb yam ntxwv ntawm lub zog tshwj xeeb lub zog hluav taws xob roj teeb raws li cov txheej txheem cua sov sab nraud. Txij thaum ntawd los, txoj kev siv hluav taws xob adiabatic tau siv dav los ntsuas qhov ntsuas kub ntawm qhov ntsuas kub ntawm lithium-ion roj teeb. Kev tshawb fawb tam sim no ntawm kev tsim txom thermal feem ntau yog ua raws li cov hluav taws xob hluav taws xob sab nraud ntawm cov roj teeb. Liu Mengmeng tau tsim cov qauv tsim hluav taws xob hloov hluav taws xob ntau endogenous thiab cov qauv electrochemical thermal coupling. Raws li cov txheej txheem hluav taws xob cua sov, cov yam ntxwv kev nyab xeeb ntawm cov roj teeb tom qab nws tus kheej ignition tshwm sim los ntawm kev tsim txom thermal. Nws tau pom tias lub roj teeb combustion tuaj yeem muab faib ua peb theem, xws li kev txhaj tshuaj combustion, ruaj khov combustion, thiab kev txhaj tshuaj thib ob. LI et al. tau kawm txog cov txiaj ntsig ntawm qhov hluav taws xob tam sim no ntawm qhov kub thiab txias hauv qab ntawm thermal runaway tshwm sim los ntawm kev tsim txom thermal. Nws tau pom tias thaum qhov tso tawm tam sim no tsis tu ncua, qhov tsis zoo, cov yam ntxwv ntawm kev nyab xeeb, thermal runaway pib kub, thiab qhov kub siab tshaj plaws thaum lub sij hawm thermal runaway tag nrho yog nyob ntawm lub roj teeb muaj peev xwm.
2.2 Kev tshawb fawb txog roj teeb thermal runaway tshwm sim los ntawm kev tsim txom hluav taws xob
Feem ntau ua rau lub roj teeb thermal runaway muaj xws li overcharging thiab tso tawm, sab hauv luv circuits, sab nraud luv luv, thiab lwm yam.
(1) Overcharge thiab tshaj tawm
Thaum lub sij hawm ua tiav ntawm lub voj voog tawm hauv lub roj teeb lithium-ion, BMS roj teeb tswj system yuav nquag thaiv cov nqi them tam sim no raws li lub xeev tus nqi. Thaum BMS system tsis ua haujlwm, overcharge lub roj teeb tuaj yeem ua rau muaj kev sib tsoo loj ntawm tus kheej. Tom qab ncav cuag qhov pib ntawm SOC thaum lub sij hawm them nyiaj, lithium hlau yuav ua raws li qhov chaw ntawm cov khoom siv hluav taws xob tsis zoo, thiab cov lithium txuas nrog yuav hnov mob nrog cov electrolyte ntawm qhov kub thiab txias, tso tawm ntau cov roj kub kub. Nyob rau tib lub sijhawm, cov khoom siv hluav taws xob zoo electrode pib yaj vim kev tshem tawm lithium ntau dhau thiab muaj peev xwm sib txawv loj nrog qhov tsis zoo electrode. Thaum qhov zoo electrode muaj peev xwm tshaj qhov kev nyab xeeb ntawm cov electrolyte, cov electrolyte tseem yuav raug oxidation cov tshuaj tiv thaiv nrog cov khoom zoo electrode active khoom. Thaum lub sij hawm overcharging txheej txheem, ib tug series ntawm sab kev xav xws li Ohmic cua sov thiab cov pa roj overflow yuav tshwm sim, exacerbating tshwm sim ntawm thermal runaway.
Cov roj tso tawm thaum lub sij hawm them nyiaj ntau dhau ntawm cov roj teeb lithium-ion feem ntau yog tsim los ntawm CO2, CO, H2, CH4, C2H6, thiab C2H4, thiab cov roj ntim thiab cov cua kub nce nrog qhov nce ntawm kev them tam sim no. Los ntawm kev siv cov calorimeter nrawm thiab lub roj teeb lub voj voog ntsuas rau kev sib koom ua ke, qhov kev sim qhia tau hais tias qhov txaus ntshai ntawm overcharging raws li qhov tam sim no qhov hluav taws xob tsis tu ncua yog ntau dua li ntawm overcharging ncaj qha nrog qhov tsis tu ncua tam sim no. Raws li qhov kev ua tau zoo tshaj ntawm kev sib xyaw zoo electrode thiab graphite tsis zoo electrode nyob rau hauv ib puag ncig kev sim sib txawv, Ren li al. Kev txiav txim siab tag nrho cov teebmeem ntawm kev them nyiaj tam sim no, cov khoom sib cais, thiab cov cua sov dissipation system. Txoj kev tshawb nrhiav pom tias cov cua sov tso tawm thaum lub sij hawm overcharging ntawm NCM roj teeb tsis zoo sib xws rau qhov loj ntawm kev them tam sim no. Lub melting point ntawm cov ntaub ntawv sib txawv thiab deformation thiab o ntawm lub roj teeb yog lub ntsiab yam tseem ceeb ua rau thermal runaway ntawm lithium-ion roj teeb. Wang et al. txheeb xyuas txoj kev thermal nthuav tawm thiab cov roj kub kub dhau ntawm cov roj teeb lithium overcharged, thiab pom tias cov cua sov tsim los ntawm cov tshuaj tiv thaiv ntawm lithium deposition thiab electrolyte thaum lub roj teeb overcharge accounted rau ntau tshaj 43%. Zhang et al. tau kawm txog cov txheej txheem degradation ntawm cov roj teeb pob muaj peev xwm raws li qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv ntawm qhov sib txawv thiab pom tias ib qho overcharge muaj qhov cuam tshuam me ntsis ntawm lub roj teeb muaj peev xwm, tab sis tom qab overcharging mus txog rau qhov zoo electrode active khoom delithiated, nws yuav cuam tshuam rau thermal stability ntawm lub roj teeb pob.
Qhov teeb meem tshwm sim los ntawm kev tso tawm ntau dua yog me dua. Thaum ntxov tshaj tawm yog qhov nyuaj ua rau thermal runaway ntawm lub roj teeb, tab sis nws tuaj yeem cuam tshuam lub peev xwm ntawm lub roj teeb. Zhou Ping et al. Kawm txog cov yam ntxwv tawm ntawm nickel cobalt manganese NCM ternary lithium roj teeb tom qab overdischarging. Thaum lub sij hawm tus txheej txheem static tawm, lub degree ntawm luv luv Circuit Court nyob rau hauv lub NCM lithium roj teeb txo, lub kuj nce, thiab cov paug tam sim no txo. Cov kev sim tau pom tias qhov tob ntawm qhov tso tawm ntau dua, qhov ntau dua qhov kev txo qis ntawm tus kheej lub hlwb hauv lub pob roj teeb. Ma et al. pom nyob rau hauv cov kev sim overdischarge ntawm lithium roj teeb uas overdischarge tsis hloov cov qauv ntawm lub roj teeb lub active cov ntaub ntawv, tab sis yuav ua rau lub dissolution ntawm lub tsis zoo electrode tam sim no collector, nce lub thickness ntawm SEI zaj duab xis, thiab accelerate lub aging ntawm lub roj teeb. Cov yam ntxwv ntawm tus cwj pwm ntawm lithium-ion roj teeb tshaj tawm cov txheej txheem yog qhia hauv daim duab.
(2) Sab nraud luv luv Circuit Court
Sab nraud luv circuits kuj yog ib qho tseem ceeb ua rau thermal runaway nyob rau hauv lub hwj chim roj teeb. Chen et al. tsim ib qho tshiab hluav taws xob thermal coupling qauv raws li kev sib xyaw ua ke ntawm kev tsim hluav taws xob, kev faib tawm, thiab kev nthuav tawm qauv. Kev tshawb fawb tau pom tias qhov kub siab tshaj plaws ntawm cov roj teeb lithium-ion nyob rau hauv cov xwm txheej luv luv sab nraud muaj nyob ntawm ntug ntawm pob ntseg electrode. Ma Taixiao et al. pom tias nyob rau hauv lub sab nraud luv luv-circuit xeev ntawm lub hwj chim roj teeb, lub tshav kub generated los ntawm sab kev cuam tshuam yog ntau me dua lub tshav kub generated los ntawm electrochemistry, thiab lub tshav kub generated los ntawm electrochemistry yog zoo correlated nrog thawj SOC, tab sis tsis zoo correlated nrog kub siab. thermal stress.
(3) Internal luv Circuit Court
Internal luv luv Circuit Court, uas tshwm sim nyob rau hauv lub roj teeb thiab yog ib qho nyuaj rau ntes tau los ntawm BMS system, yog lub ntsiab ua rau thermal runaway nyob rau hauv lithium-ion roj teeb. Thaum lub roj teeb yog overcharged los yog overdischarged, lithium dendrites maj mam loj hlob mus rau hauv lub SEI zaj duab xis, ua rau sab hauv short circuits thiab sai ua rau uncontrolled kub nce thiab thermal runaway. Tsis tas li ntawd, kev puas tsuaj lattice lossis cov khoom siv tam sim no tshwm sim los ntawm kev tsim cov txheej txheem ntawm cov roj teeb kuj tuaj yeem ua rau muaj kev cuam tshuam luv luv.
2.3 Kev tshawb fawb txog roj teeb thermal runaway tshwm sim los ntawm kev tsim txom txhua yam
Nyob rau hauv daim ntawv thov ntawm automotive fais fab roj teeb, mechanical failures yog inevitably tshwm sim los ntawm kev huam yuaj. Yog hais tias lub roj teeb pob yog deformed los ntawm sab nraud quab yuam xws li puncture thiab compression, nws tuaj yeem ua rau kev hloov hauv cov qauv thiab txawm tias ua rau thermal runaway vim kev sib cuag ncaj qha ntawm cov ncej zoo thiab tsis zoo nyob rau hauv kev ntxhov siab heev. Yog li ntawd, nws yog ib qho tsim nyog los ua kev tshawb fawb txog roj teeb thermal runaway tshwm sim los ntawm kev tsim txom txhua yam, ntawm cov Fan Wenjie thiab Xu Huiyong tau tshawb fawb txog thermal runaway tshwm sim los ntawm kev tsim txom txhua yam raws li cov qauv tsim qauv thiab kev soj ntsuam cov lej.
Wang et al. tau ua ib txoj kev tshawb fawb txog kev hloov pauv ntawm cov roj teeb pob tom qab sib tsoo raws li cov roj teeb lithium-ion muag muag. Qhov kev sim puncture pom tau tias ntau lub zos deformations thiab shear fracture txheej tshwm sim nyob rau hauv lub roj teeb pob thaum lub sij hawm puncture txheej txheem, thiab lub kua muag ntawm lub tam sim no collector thiab zoo electrode active khoom, nrog rau cov rearrangement ntawm lub internal qauv ntawm lub roj teeb. pob, tshwm sim los ntawm kev sib tsoo ntawm qhov sib cais, yog cov laj thawj tseem ceeb rau qhov luv luv Circuit Court thermal runaway hauv lub roj teeb. Lamb et al. kawm txog lub xeev deformation ntawm 18650 cylindrical lithium-ion roj teeb nyob rau hauv puncture tej yam kev mob raws li computer tomography technology. Qhov kev sim pom tias qhov tshwm sim infiltration ntawm qhov zoo thiab qhov tsis zoo electrodes exacerbates qhov tshwm sim ntawm sab hauv luv circuits. Thaum lub sij hawm luv luv, cov ntawv txuas nrog aluminium ntawv ci yaj, tsim ntau cov hlaws hlau ntawm qhov tawg. Li et al. tsim finite element tsom xam qauv rau ntau lub xeev ntawm mechanical tsim txom raws li puncture, compression, thiab lwm yam., thiab tsim ib tug kev kawm algorithm rau kwv yees lub thermal runaway txheej txheem ntawm cov roj teeb uas tsis siv cov roj teeb pov tseg. Qhov cuam tshuam ntawm kev tsim txom cov neeg siv khoom ntawm kev nyab xeeb ntawm cov roj teeb lithium-ion tau txheeb xyuas raws li yim hom kev txwv, suav nrog kev cuam tshuam quab yuam, kev sib tsoo lub kaum sab xis, thiab deformation ntau yam, txo qis kev suav cov complexity.
Kev tsim txom txhua yam uas tshwm sim hauv kev siv tswv yim yog qhov nyuaj tshaj li ib qho kev sim xws li puncture thiab compression. Kev cia siab ib leeg ntawm kev sim simulation tsis tuaj yeem kawm tob txog kev nyab xeeb ntawm cov roj teeb kev tsim txom. Cov kev daws teeb meem tseem ceeb yog txhawm rau txhim kho lub roj teeb teeb tsa txoj haujlwm, teeb tsa BMS txhim khu kev qha, thiab txhim kho cov qauv ntawm lub tsheb thav duab thaum tsim lub zog roj teeb pob, txhawm rau txo qis deformation thiab compression ntawm lub hwj chim roj teeb pob thaum muaj kev sib tsoo. .
3. Kev tiv thaiv kev ntsuas thiab cov txheej txheem rau thermal runaway ntawm lithium-ion roj teeb
Nrog rau lub hom phiaj ntawm kev thaiv, ncua, thiab tiv thaiv thermal runaway ntawm cov roj teeb hluav taws xob, ntau tus kws tshawb fawb tau tshawb fawb txog cov roj teeb pob thermal tswj, lub zog siab roj teeb pob qauv tsim, thiab lwm yam.
3.1 Kev ruaj ntseg tsim ntawm tus kheej roj teeb
(1) Kev tshawb fawb txog kev nyab xeeb ntawm Diaphragm Design
Lub hauv paus ntawm kev txhim kho kev nyab xeeb ntawm lub diaphragm yog nyob rau hauv kev nce qhov kub ntawm qhov diaphragm cog lus thiab melts, txhim kho nws lub peev xwm kub-kub cais. Lub peev xwm kub-kub cais tawm ntawm lub diaphragm kom ntseeg tau tias nws cov micropores raug kaw hauv qhov chaw kub kub, thaiv qhov ntws ntawm lithium ions. Cov khoom siv dav siv diaphragm feem ntau yog them nrog ceramic coatings lossis lwm yam ntaub ntawv nrog cov teebmeem ntawm tes kaw.
(2) Kev tshawb fawb txog kev nyab xeeb ntawm cov khoom siv hluav taws xob zoo
Feem ntau cov lithium-ion zoo electrode active khoom siv nyob rau hauv lub hwj chim roj teeb kev lag luam feem ntau yog LiCoO2, LiFePO4, LiMn2O4, LiNixCoyMnzO2 (NCM), thiab lwm yam. thiab thermal stability, xws li ZrO2 thiab AlF3. Zhang et al. tsim ib txheej ternary NCM cov ntaub ntawv raws li gradient faib ntawm atomic concentration, nrog Ni raws li cov tub ntxhais thiab Mn npog txheej txheej ntawm cov khoom txuas. Cov kev ntsuam xyuas tau pom tias nws tuaj yeem tswj tau zoo caij tsheb kauj vab thiab thermal stability txawm tias nyob rau hauv ntau qhov kub thiab txias thiab overcharge.
(3) Kev tshawb fawb txog kev nyab xeeb ntawm cov khoom siv hluav taws xob tsis zoo
Kev txhim kho ntawm qhov tsis zoo electrode kev nyab xeeb yog ua tiav los ntawm cov khoom siv txheej lossis ntxiv cov khoom siv ntxiv rau cov electrolyte los txhim kho cov thermal stability ntawm SEI zaj duab xis. Xu et al. ntxiv kua alloy GaSnIn rau cov electrolyte los txhim kho lub thermal stability ntawm lub roj teeb. Qhov kev sim qhia tau hais tias qhov npaj gradient SEI txheej zoo heev txo qhov voltage polarization thiab txhim kho Coulomb efficiency rau 99.06%. Zheng et al. npaj ib qho ultra-nyias aramid nanofiber (ANF) daim nyias nyias los suppress lithium dendrite kev loj hlob. Nyob rau hauv kev sim, nyob rau hauv ib tug high tam sim no ceev ib puag ncig ntawm 50mA / cm2, lub peev xwm ntawm ANF-Li|LiFePO4 roj teeb tag nrho poob rau 80.2% tom qab 1200 cycles. Thiab thawj zaug, nws cov kev tshawb fawb tau tshawb pom fibrous lithium deposition, thiab ANF membrane npaj nrog nanoscale pores txhawb electrolyte diffusion, ceev lithium thauj efficiency, thiab tshem tawm cov drawbacks ntawm micrometer loj lithium dendrites nkag mus rau hauv daim nyias nyias.
(4) Kev Tshawb Fawb Txog Kev Nyab Xeeb ntawm Electrolytes
Feem ntau cov xwm txheej thermal khiav mus rau electrolyte, thiab kev txhim kho electrolyte kev nyab xeeb los tiv thaiv thermal runaway yog qhov tseem ceeb. Cov nplaim hluav taws, cov khoom siv polymer, lossis cov kua ionic feem ntau ntxiv rau cov electrolyte ua cov khoom siv tiv thaiv overcharge. Fluorinated ethylene carbonate (FEC) yog cov khoom siv hluav taws xob ntau tshaj plaws, uas muaj qhov zoo ntawm kev txhim kho Coulombic efficiency ntawm reversible lithium tshem tawm hauv qhov tsis zoo electrode los ntawm kev hloov SEI zaj duab xis muaj pes tsawg leeg. Li et al. tsim ob txheej txheej crystalline thiab polymer khoom electrolyte interphase SEI zaj duab xis siv lithium difluoroborate (LiDFOB) ua cov ntsev tseem ceeb hauv cov phosphate electrolyte sib xyaw. Cov nplaim hluav taws kub hnyiab tau pom tias lub sijhawm tua tus kheej ntawm cov nplaim hluav taws xob hluav taws xob yog 6.1 vib nas this, thiab qhov rov qab ua haujlwm ntawm Li yog 98.2%. Tom qab 150 tus nqi tawm mus, nws tseem khaws 89.7% ntawm lub peev xwm roj teeb.
3.2 Kev tiv thaiv kev nyab xeeb thiab kev tsim kho kom zoo ntawm lub zog roj teeb
(1) Optimization tsim ntawm lub roj teeb pob qauv
Kev tsim cov qauv roj teeb pob thiab kev ua kom zoo ntawm lub tsheb teeb tsa txoj haujlwm yog qhov tseem ceeb rau kev txhim kho kev nyab xeeb. Chen et al. tau ua ib qho kev sim cais ntawm qhov cuam tshuam ntawm thermal runaway range raws li 18650 roj teeb layout. Qhov kev sim qhia tau hais tias lub sij hawm ignition luv dua, thiab kev sib kis ceev thiab ntau yam loj dua nyob rau hauv cov cheeb tsam uas muaj cua sov loj dua. Tab sis nws txoj kev sim tsuas yog txiav txim siab tag nrho cov cua sov ntawm lub hwj chim roj teeb module thiab tsis tau coj mus rau hauv tus account lub zos overheating tshwm sim los ntawm sab hauv luv circuits. Liu Zhenjun et al. optimized tus tsim ntawm lub roj teeb pob raws li ib tug peb-dimensional tshav kub dissipation qauv ntawm lub hwj chim roj teeb pob thiab ua tshav kub dissipation simulation. Qhov kev sim tau pom tias qhov kub siab tshaj plaws ntawm lub roj teeb lithium-ion tau zoo tau txo qis los ntawm 46 degree mus rau 34 degree, thiab qhov kub ntawm qhov sib txawv ntawm ib tus neeg lub hlwb raug tswj tsis pub dhau 5 degree.
(2) Tsim cov roj teeb Thermal Management System
Cov roj teeb lithium ion muaj zog thermal rhiab heev, thiab kev txhim kho qis-kub paug efficiency thiab high-temperature kev nyab xeeb yog lub hauv paus ntawm roj teeb thermal tswj systems. Cov kev ua kom txias rau cov pob roj teeb muaj xws li ua kua txias thiab cua txias. Tesla lub tsheb fais fab txhua tus siv cov tshuab ua kua ua kua, thaum lub tsheb npav hluav taws xob feem ntau siv cua txias. Nyob rau hauv xyoo tas los no, xws li aerogels, theem hloov cov ntaub ntawv thiab hybrid cov ntaub ntawv tau siv nyob rau hauv lub roj teeb thermal tswj systems vim lawv zoo heev tshav kub nqus efficiency. Wu et al. tau tsim cov khoom siv tau yooj yim rau cov roj teeb thermal tswj system raws li hydrogel. Tsawg nqi sodium polyacrylate khoom siv. Nws cov plasticity tsis tshua muaj zog tuaj yeem ua rau ntau yam duab thiab muab tso rau hauv lub pob roj teeb, uas tuaj yeem paub txog cov txiaj ntsig ntawm cov cua sov ntawm cov cua txias thiab ua kua txias.
(3) Tsim cov cua txias, tua hluav taws, thaiv, thiab kev taw qhia roj rau roj teeb thermal khiav tawm
Thaum lub roj teeb thermal runaway tsis tuaj yeem zam tau, nws yog qhov tseem ceeb tshwj xeeb kom ceev nrooj thaiv thiab ua kom cov cua sov sib kis thiab coj cov roj kub kub kom tsis txhob cuam tshuam cov roj teeb uas tau teeb tsa nyob ze.
Txoj hauv kev tseem ceeb los tiv thaiv kev sib kis ntawm thermal runaway muaj xws li: sau cov nplaim hluav taws xob tawm xov xwm, siv cov ntaub ntawv rwb thaiv tsev kom cais cov roj teeb thermal runaway, lossis coj cov nplaim taws thiab cov roj kub kub tawm ntawm lub roj teeb los ntawm txoj kev. Xu et al. tsim cov roj kub kub dissipation tube nrog cov duab plaub sib dhos ua ke nrog cov roj teeb raws li pom hauv daim duab 5. Txawm hais tias nws tsis tuaj yeem tiv thaiv qhov tshwm sim ntawm thermal runaway nyob rau hauv ib tus neeg cov roj teeb, nws tuaj yeem tiv thaiv kev sib kis ntawm cov thermal runaway hauv zos. roj teeb pob. Li Haoliang et al. tsim lub thermal kis thaiv qhov system thiab kev tswj hwm kev sib koom ua ke raws li cov pa roj tsis zoo thiab cov tub yees sib xyaw. Raws li daim duab tshav kub dispersion thiab cua sov acceleration, ib tug pib yog teem rau lub thaiv system. Qhov kev sim qhia tau hais tias nws tuaj yeem thaiv cov cua kub tawm thaum lub roj teeb pob hauv zos overheated.
4. Cov lus xaus
Cov kab lus piav qhia txog cov ntaub ntawv hais txog kev ua kom muaj zog, ua rau, thiab kev tswj xyuas kev nyab xeeb ntawm thermal runaway nyob rau hauv lithium-ion fais fab roj teeb.
(1) Nyob rau hauv kev tshawb fawb ntawm thermal runaway mechanism, thermal stability thiab tshav kub tso cai txoj cai ntawm lub ntsiab Cheebtsam ntawm lithium-ion roj teeb tau soj ntsuam, thiab cov hauv paus ntsiab lus ntawm cov tshuaj tiv thaiv tshav kub txheej txheem xws li electrolyte decomposition, separator, roj teeb active cov ntaub ntawv, thiab adhesives tau piav qhia.
(2) Hauv kev tshawb fawb txog qhov ua rau muaj kev cuam tshuam ntawm thermal runaway, cov yam ntxwv thiab cov laj thawj ntawm cov xwm txheej sib txawv tau raug cais tawm thiab suav nrog, xws li kev tsim txom cov khoom siv hluav taws xob, kev tsim txom hluav taws xob, thiab roj teeb thermal runaway tshwm sim los ntawm kev tsim txom thermal.
(3) Nyob rau hauv cov nqe lus ntawm kev tiv thaiv thiab saib xyuas thermal runaway, tsab xov xwm no piav qhia txog kev tshawb fawb los txhim kho kev nyab xeeb ntawm lithium-ion fais fab roj teeb thermal runaway los ntawm peb yam: optimization tsim ntawm lithium-ion roj teeb hlwb, optimization ntawm lub hwj chim roj teeb systems, thiab roj teeb thermal tswj thiab saib xyuas cov lus ceeb toom.
Txawm hais tias qhov kev vam meej tseem ceeb tau ua tiav hauv txoj kev tshawb fawb ntawm thermal runaway hauv lithium-ion roj teeb, tseem muaj qhov sib txawv hauv qee qhov kev tshawb fawb. Kev tshawb fawb txog qhov cuam tshuam ntawm kev laus ntawm kev nyab xeeb tshwm sim los ntawm superposition ntawm lub voj voog lub sij hawm ntawm cov roj teeb lithium-ion tsuas yog pib nyob rau xyoo tas los no, tshwj xeeb tshaj yog kev sim kev tshawb fawb ntawm txoj kev laus thiab cov txheej txheem ntawm thermal stability tseem tsis tshua muaj. Nyob rau tib lub sijhawm, tsuas muaj qee qhov kev sim kev tshawb fawb txog kev kwv yees thiab kev ua qauv ntawm cov nplaim hluav taws xob tom qab thermal runaway tshwm sim, thiab tseem tsis muaj cov lej simulation tsom xam ntawm nplaim hluav taws. Nws tuaj yeem pom tias kev tswj hwm kev nyab xeeb ntawm thermal runaway nyob rau hauv lithium-ion fais fab roj teeb tseem nyob rau theem kev txhim kho, tshwj xeeb tshaj yog nyob rau hauv kev taw qhia ntawm kev ceeb toom thiab thaiv, uas yuav tsum tau tshawb fawb ntxiv.