Cov roj teeb lithium muaj qhov zoo ntawm kev txav mus los thiab them ceev, yog li vim li cas cov roj teeb txhuas-acid thiab lwm cov roj teeb nruab nrab tseem nyob hauv khw?
Ntxiv nrog rau cov teeb meem ntawm tus nqi thiab daim ntawv thov sib txawv, lwm qhov laj thawj yog kev ruaj ntseg.
Lithium yog cov hlau nquag tshaj plaws hauv ntiaj teb.Vim tias nws cov yam ntxwv ntawm cov tshuaj muaj zog heev, thaum cov hlau lithium raug rau saum huab cua, nws yuav muaj cov tshuaj tiv thaiv oxidation hnyav nrog oxygen, yog li nws muaj feem cuam tshuam rau kev tawg, tawg thiab lwm yam tshwm sim.Tsis tas li ntawd, cov tshuaj tiv thaiv redox tseem yuav tshwm sim hauv cov roj teeb lithium thaum lub sijhawm them thiab tawm.Kev tawg thiab spontaneous combustion yog tshwm sim los ntawm tsub zuj zuj, diffusion thiab tso tawm ntawm lithium roj teeb tom qab cua sov.Hauv luv luv, cov roj teeb lithium yuav tsim kom muaj cua sov ntau thaum lub sijhawm them thiab tawm, uas yuav ua rau qhov kub thiab txias ntawm lub roj teeb thiab qhov kub tsis sib xws ntawm cov roj teeb ib leeg, yog li ua rau lub roj teeb tsis ruaj khov.
Kev coj tus cwj pwm tsis zoo ntawm cov roj teeb lithium-ion thermal (nrog rau cov roj teeb overcharge thiab overdischarge, ceev ceev thiab tso tawm, luv luv Circuit Court, kev tsim txom cov neeg kho tshuab, kub thermal shock, thiab lwm yam) yuav ua rau muaj kev phom sij txaus ntshai hauv lub roj teeb thiab tsim kom muaj cua sov, ncaj qha ua rau cov zaj duab xis passive ntawm qhov tsis zoo electrode thiab zoo electrode nto.
Muaj ntau ntau yam ua rau ua rau muaj kev kub ntxhov ntawm cov roj teeb lithium ion.Raws li cov yam ntxwv ntawm triggering, nws tuaj yeem muab faib ua kev tsim txom kev tsim txom, kev tsim txom hluav taws xob thiab kev tsim txom thermal.Kev tsim txom txhua yam: hais txog kev siv tshuaj acupuncture, extrusion thiab hnyav khoom cuam tshuam los ntawm kev sib tsoo tsheb;Kev tsim txom hluav taws xob: feem ntau tshwm sim los ntawm kev tswj hluav taws xob tsis raug lossis hluav taws xob tsis ua haujlwm, suav nrog luv luv Circuit Court, overcharge thiab overdischarge;Kev tsim txom thaum tshav kub kub: tshwm sim los ntawm overheating tshwm sim los ntawm kev tswj kub tsis raug.
Peb txoj hauv kev ua rau muaj kev cuam tshuam.Kev tsim txom txhua yam yuav ua rau deformation lossis rupture ntawm lub roj teeb diaphragm, uas ua rau muaj kev sib cuag ncaj qha ntawm tus ncej zoo thiab tsis zoo ntawm lub roj teeb thiab luv luv Circuit Court, ua rau muaj hluav taws xob tsim txom;Txawm li cas los xij, nyob rau hauv qhov xwm txheej ntawm kev tsim hluav taws xob, cov hluav taws xob tsim hluav taws xob xws li Joule kub nce, ua rau lub roj teeb kub nce, uas ua rau muaj kev kub ntxhov, ua rau cov saw hlau hom hluav taws xob tsim hluav taws xob sab hauv lub roj teeb, thiab thaum kawg ua rau qhov tshwm sim. ntawm roj teeb cua sov khiav.
Lub roj teeb thermal runaway yog tshwm sim los ntawm qhov tseeb tias qhov hluav taws xob tsim hluav taws xob ntawm lub roj teeb muaj ntau dua li cov cua sov dissipation tus nqi, thiab cov cua sov tau sau ntau heev tab sis tsis dissipated nyob rau hauv lub sij hawm.Nyob rau hauv qhov tseeb, "thermal runaway" yog ib tug zoo lub zog tawm tswv yim voj voog txheej txheem: qhov nce kub yuav ua rau lub cev kub, thiab qhov kub yuav nce tom qab lub cev kub, uas nyob rau hauv lem yuav ua rau lub cev kub.
Cov txheej txheem ntawm thermal runaway: thaum lub roj teeb sab hauv kub nce, SEI zaj duab xis nyob rau saum npoo ntawm SEI zaj duab xis decomposes nyob rau hauv qhov kub thiab txias, lithium ion embedded nyob rau hauv graphite yuav hnov mob nrog cov electrolyte thiab cov binder, ntxiv thawb lub roj teeb kub. mus txog 150 ℃, thiab cov tshuaj tiv thaiv exothermic tshiab yuav tshwm sim ntawm qhov kub thiab txias.Thaum lub roj teeb kub siab tshaj 200 ℃, cov khoom cathode decomposes, tso tawm ntau cov cua sov thiab roj, thiab lub roj teeb pib bulge thiab tsis tu ncua heats li.Lub lithium embedded anode pib teb nrog cov electrolyte ntawm 250-350 ℃.Cov khoom siv cathode tau pib ua rau cov tshuaj tiv thaiv decomposition hnyav, thiab cov electrolyte tau dhau los ua cov tshuaj tiv thaiv oxidation, tso tawm ntau cov cua sov, ua kom kub thiab muaj roj ntau, ua rau combustion thiab tawg ntawm lub roj teeb.
Qhov teeb meem ntawm lithium dendrite nag lossis daus thaum overcharge: Tom qab lub roj teeb lithium cobalate tau them tag nrho, ntau cov lithium ions tseem nyob hauv qhov zoo electrode.Qhov ntawd yog hais tias, lub cathode tsis tuaj yeem tuav ntau lithium ions txuas rau cathode, tab sis nyob rau hauv lub xeev overcharged, cov lithium ions ntau dhau ntawm lub cathode tseem yuav ua luam dej mus rau cathode.Vim tias lawv tsis tuaj yeem ntim tau tag nrho, hlau lithium yuav tsim rau ntawm cathode.Txij li cov hlau lithium no yog cov siv lead ua dendritic, nws hu ua dendrite.Yog tias lub dendrite ntev dhau lawm, nws yooj yim rau tho lub diaphragm, ua rau sab hauv luv luv.Raws li cov ntsiab lus tseem ceeb ntawm electrolyte yog carbonate, nws qhov hluav taws xob thiab qhov kub ntawm qhov kub yog tsawg, yog li nws yuav kub hnyiab lossis tawg ntawm qhov kub thiab txias.
Yog hais tias nws yog ib tug polymer lithium roj teeb, lub electrolyte yog colloidal, uas yog nquag combustion ntau combustion.Yuav kom daws tau qhov teeb meem no, cov kws tshawb fawb sim hloov cov khoom siv cathode zoo dua.Cov khoom siv ntawm lithium manganate roj teeb muaj qee qhov zoo.Nws tuaj yeem ua kom ntseeg tau tias lithium ion ntawm qhov zoo electrode tuaj yeem nkag mus rau hauv cov pa roj carbon qhov ntawm qhov tsis zoo electrode nyob rau hauv tag nrho cov nqi hluav taws xob, es tsis txhob muaj qee yam residues hauv cov electrode zoo li lithium cobalate, uas rau qee qhov kev zam ntawm tiam. dendrites.Cov qauv ruaj khov ntawm lithium manganate ua rau nws qhov kev ua haujlwm oxidation qis dua lithium cobalate.Txawm hais tias muaj ib qho luv luv Circuit Court sab nraud (tshwj tsis yog ib qho luv luv Circuit Court), nws tuaj yeem zam kev sib tsoo thiab tawg los ntawm lithium hlau nag lossis daus.Lithium hlau phosphate muaj ntau dua thermal stability thiab qis oxidation peev xwm ntawm electrolyte, yog li nws muaj kev nyab xeeb siab.
Kev laus attenuation ntawm lithium ion roj teeb yog manifested los ntawm lub peev xwm attenuation thiab internal kuj nce, thiab nws cov kev laus attenuation mechanism muaj xws li poob ntawm zoo thiab tsis zoo active cov ntaub ntawv thiab poob ntawm muaj lithium ions.Thaum cov khoom siv cathode yog hnub nyoog thiab lwj, thiab lub peev xwm ntawm cov cathode tsis txaus, qhov kev pheej hmoo ntawm lithium evolution los ntawm cathode yuav tshwm sim ntau dua.Nyob rau hauv cov xwm txheej ntawm tshaj tawm, lub peev xwm ntawm cathode rau lithium yuav nce mus rau saum toj 3V, uas yog siab tshaj li qhov muaj peev xwm tawg ntawm tooj liab, ua rau cov khoom tawg ntawm tooj liab.Dissolved tooj liab ions yuav precipitate ntawm lub cathode nto thiab tsim tooj liab dendrites.Copper dendrites yuav dhau los ntawm lub diaphragm, ua rau sab hauv luv luv, uas cuam tshuam rau kev nyab xeeb ntawm lub roj teeb.
Tsis tas li ntawd, lub overcharge tsis kam ntawm cov roj teeb kev laus yuav txo qis rau qee qhov, feem ntau yog vim qhov nce ntawm kev tiv thaiv sab hauv thiab txo qis ntawm cov khoom zoo thiab tsis zoo, ua rau muaj qhov nce ntawm joule tshav kub thaum lub sij hawm overcharging txheej txheem ntawm cov roj teeb.Nyob rau hauv tsawg dua overcharging, sab kev tshwm sim yuav tshwm sim, ua rau lub thermal runaway ntawm roj teeb.Nyob rau hauv cov nqe lus ntawm thermal stability, lithium evolution ntawm lub cathode yuav ua rau ib tug ntse poob nyob rau hauv lub thermal stability ntawm lub roj teeb.
Nyob rau hauv ib lo lus, kev nyab xeeb kev ua tau zoo ntawm lub hnub nyoog roj teeb yuav raug txo kom tsawg, uas yuav ua rau mob hnyav rau kev nyab xeeb ntawm lub roj teeb.Qhov kev daws teeb meem tshaj plaws yog txhawm rau txhim kho lub roj teeb lub zog cia nrog lub roj teeb tswj system (BMS).Piv txwv li, 8000 18650 roj teeb uas siv hauv Tesla Model S tuaj yeem paub txog kev saib xyuas lub sijhawm ntawm ntau lub cev ntawm lub roj teeb, ntsuas lub roj teeb siv cov xwm txheej, thiab ua kev kuaj mob online thiab ceeb toom ntxov los ntawm nws cov roj teeb tswj.Nyob rau tib lub sijhawm, nws tseem tuaj yeem ua qhov tso tawm thiab tswj xyuas ua ntej, kev tswj hwm roj teeb thiab kev tswj xyuas thermal.
Post lub sij hawm: Dec-02-2022