Cov laj thawj rau lub roj teeb deformation thiab nthuav dav tom qab caij tsheb kauj vab
Ntiaj teb no renowned lithium polymer roj teeb tuam txhab-JXBT
Tom qab kev caij tsheb kauj vab, cov laj thawj rau roj teeb deformation thiab nthuav dav:
Cov ncej ncej nthuav dav yog muab faib ua lub cev thiab tshuaj lom neeg nthuav dav;
1. Lub cev nthuav dav:
Yog vim li cas tsom xam ntawm winding cell:
Tom qab ua grating los yog caij tsheb kauj vab ob peb lub lis piam, qhov nruab nrab - thiab - me me winding lithium polymer roj teeb deforms nyob rau hauv txoj kev tuab. Tom qab lub roj teeb raug them thiab tso tawm, vim yog qhov deformation ntawm cov khoom siv (feem ntau yog cov ncej ncej thiab cov yeeb yaj kiab sib cais), cov txheej txheem sab hauv ntawm lub xov tooj ntawm tes me dhau ntawm lub ces kaum, thiab qhov kev ntxhov siab yog tsim los ntawm qhov dav ntawm lub xov tooj ntawm tes, uas ua rau lub xov tooj ntawm tes sib tw thiab lub xov tooj ntawm tes kom khoov thiab deform;
2. Tshuaj expansion:
Cov tshuaj lom neeg yog tshwm sim raws li kev nthuav dav ntawm tus ncej;
Lithium{0}} ion roj teeb ntawm tes tuab yog nce thaum them nyiaj, uas yog vim qhov nthuav dav ntawm qhov tsis zoo electrode. Qhov zoo electrode expansion tus nqi tsuas yog 2 ~ 4%, thiab qhov tsis zoo electrode feem ntau yog tsim los ntawm graphite, binder, thiab conductive carbon. Tus nqi nthuav dav ntawm cov khoom siv graphite nws tus kheej nce mus txog 10%. Lub ntsiab tseem ceeb cuam tshuam rau kev hloov pauv ntawm graphite tsis zoo electrode expansion tus nqi suav nrog: SEI zaj duab xis tsim, Lub Xeev Tus Nqi (SOC) thiab lwm yam.
(a). SEI zaj duab xis tsim: Thaum lub sij hawm thawj tus nqi thiab tso tawm ntawm lithium ion roj teeb, cov electrolyte undergoes ib tug txo cov tshuaj tiv thaiv ntawm cov graphite hais ntawm cov khoom -kua interface, tsim ib tug passivation txheej (SEI zaj duab xis) npog lub nto ntawm cov khoom siv electrode. Cov tiam ntawm SEI zaj duab xis ua rau cov anode thickness Qhov tseem ceeb nce, thiab vim yog SEI zaj duab xis, lub thickness ntawm lub xov tooj ntawm tes nce li ntawm 4%. Los ntawm qhov kev xav ntawm lub sij hawm ntev - lub sij hawm voj voog txheej txheem, raws li cov qauv ntawm lub cev thiab qhov chaw tshwj xeeb ntawm cov graphite sib txawv, cov txheej txheem voj voog yuav tshwm sim qhov kev sib cais ntawm SEI thiab cov txheej txheem dynamic ntawm SEI tshiab. Piv txwv li, flake graphite muaj qhov nthuav dav ntau dua li cov graphite kheej kheej.
(b). Thaum lub sij hawm lub voj voog ntawm lub xeev them nqi, qhov ntim nthuav dav ntawm graphite anode thiab cell SOC muaj kev sib raug zoo nrog lub sijhawm ua haujlwm, uas yog, raws li lithium ions tau txuas ntxiv mus rau hauv graphite (lub cell SOC nce), lub ntim maj mam nthuav thaum lithium ions raug tso tawm los ntawm graphite anode, cell SOC maj mam txo, thiab cov graphite sib thooj.
(c). (3) Los ntawm qhov kev xav ntawm qhov compaction ceev ntawm cov khoom, lub compaction ceev muaj ib tug ntau dua ntawm cov graphite anode. Thaum lub sij hawm txias nias ntawm tus ncej, ib tug loj compressive kev nyuaj siab yog generated nyob rau hauv lub graphite anode zaj duab xis txheej. Qhov kev ntxhov siab no yog ci ntawm qhov kub thiab txias hauv cov ncej tom ntej Nws yog qhov nyuaj rau kev tso tawm tag nrho cov txheej txheem. Thaum lub roj teeb raug them thiab tawm mus cyclically, vim muaj kev sib cuam tshuam ntawm lithium ion ntxig thiab rho tawm, electrolyte o ntawm cov nplaum, thiab lwm yam, qhov kev ntxhov siab ntawm daim nyias nyias raug tso tawm thaum lub voj voog thiab qhov nthuav dav nce. Ntawm qhov tod tes, lub compaction ceev txiav txim qhov loj ntawm lub pore ntim ntawm anode membrane txheej. Lub pore ntim nyob rau hauv lub membrane txheej yog loj, uas muaj peev xwm nqus tau qhov nthuav ntim ntawm tus ncej. Lub pore ntim yog me me. Thaum tus ncej nthuav dav, tsis muaj qhov chaw txaus los nqus qhov nthuav dav. Lub generated ntim, nyob rau lub sij hawm no, tsuas yog nthuav mus rau sab nraud ntawm lub membrane txheej, uas yog qhia raws li lub ntim expansion ntawm lub anode daim ntawv.
(d). Other factors: the adhesive strength of the adhesive (adhesive strength of the interface between the adhesive, graphite particles, conductive carbon and current collector), charge and discharge rate, the swelling ability of the adhesive and the electrolyte, the shape of the graphite particles Its bulk density and the increase in volume of the pole piece caused by the failure of the adhesive during the cycle have a certain effect ntawm lub anode expansion.
Kev suav ntawm expansion rate:
(Cov roj teeb tuab tom qab nthuav dav- Roj teeb tuab ua ntej nthuav dav) / Roj teeb tuab ua ntej nthuav * 100%
Lub expansion coefficient yog lub cev yam ntxwv ntawm lub roj teeb, thiab lub voj voog lub neej yog cov yam ntxwv electrochemical. Tsis muaj kev sib raug zoo ntawm ob leeg. Lub voj voog lub neej yog hais txog lub sijhawm uas lub roj teeb tuaj yeem siv tau ntau zaus.
Cov kev xeem uas yuav tsum tau ua rau lub voj voog: 1C them thiab tso tawm tam sim no, 300 lub voj voog, lub roj teeb tsis xau, tsis muaj hluav taws, tsis tawg, thiab lub roj teeb muaj peev xwm ntau dua lossis sib npaug li 80%, uas qhia tau tias tsim nyog.
Xav txog cov khoom kawg, yog tias lub roj teeb nthuav dav tsis cuam tshuam rau kev siv cov khoom (piv txwv li, lub roj teeb nthuav dav tsis ua rau lub tsev ntawm cov khoom nthuav dav / deform lub rooj plaub), thiab tom qab lub voj voog ua tau raws li ntau yam kev qhia, lub roj teeb tuaj yeem siv tau ib txwm;
