Kev soj ntsuam ntawm CATL phosphate them lithium roj teeb kub cia kev ua haujlwm attenuation ua rau

著者：Iflowpower – ຜູ້ຜະລິດສະຖານີພະລັງງານແບບພົກພາ

Catlcatl siv nws txoj kev lag luam lithium hlau phosphate ion roj teeb los tshawb txog nws cov laj thawj rau kev cia lub peev xwm poob hauv qhov chaw hluav taws xob, 60 ° C. Mechanism ntawm roj teeb muaj peev xwm attenuation los ntawm roj teeb thiab ncej theem system los ntawm lub cev characterization thiab electrochemical kev ntsuam xyuas. I.

Kev sim txheej txheem kev sim siv CATL tsim cov square phosphate ion roj teeb nrog 86AH. Lub roj teeb yog cov khoom siv hluav taws xob zoo hauv LifePO4, graphite yog cov khoom siv tsis zoo electrode, siv cov polyethylene separator thiab LiPF6 electrolyte. Xaiv 20 lub roj teeb nyob ze rau tib batch thiab kev ua haujlwm hluav taws xob los khaws cia, sim ntsuas hluav taws xob ntawm lub roj teeb.

100% SOC roj teeb 60 ° C yog khaws cia hauv xovxwm ntawm 2.50 txog 3.65V, tawm ntawm 0.

5C magnification - them lub voj voog. Tom qab ntawd lub roj teeb uas muaj peev xwm rov qab tau khaws cia ntawm 60 ° C. Xws li rov ua dua, kaw lub peev xwm attenuation txheej txheem ntawm lub roj teeb.

Thaum txhua qhov kev sim muaj peev xwm, DC sab hauv tsis kam (DCR) ntawm lub roj teeb 5C / 30S raug kuaj. Siv lub roj teeb los ntawm ntau lub sijhawm cia thiab nyob rau hauv lub xeev tawm tag nrho, disassembled hauv AR gas hnab looj tes. Siv daim teb emission scanning electron microscope los soj ntsuam lub ncov qaumteb qabteb morphology, siv ib tug tshwj xeeb deg analyzer los ntsuam xyuas qhov chaw deg.

Hauv lub hnab looj tes, cov khoom siv hluav taws xob tau muab khi nrog daim kab xev pob tshab, thiab cov khoom siv hluav taws xob raug tshuaj xyuas siv X-ray diffractometer. Lub ncov qaumteb qabteb tom qab lub roj teeb tawg yog cov electrode ua haujlwm, daim ntawv lithium yog lub txee electrode, thiab tau nruab rau hauv CR2032 buckle roj teeb, thiab cov khoom siv hluav taws xob ntawm cov yin thiab cov phaj tsis zoo. Electrochemical impedance spectrum ntawm buckle roj teeb nrog electrochemical workstation.

Kev tshuaj xyuas cov ntsiab lus ntawm cov ntawv electrode siv ib qho inductive coupling plasma emission spectrometer. Qhov thib ob, cov txiaj ntsig tau sib tham 1. Kev ntsuam xyuas roj teeb Daim duab 1 yog lub roj teeb muaj peev xwm attenuation thiab them thiab tawm kev ua haujlwm.

Nrog rau ncua sij hawm cia, roj teeb muaj peev xwm maj mam lwj. Thaum lub sij hawm cia mus txog 575d, lub roj teeb muaj peev xwm attenuation yog 85.8% ntawm thawj lub peev xwm.

Lub roj teeb tau them thiab tawm ntawm 0.02 C, thiab cov roj teeb nruab nrab ntawm qhov hluav taws xob muaj cov lithium ions kos los ntawm ntau lub platforms tshwm sim los ntawm graphite, qhia tias 0.02c magnification tau muab rau cov qauv graphite hauv cov qauv graphite thaum lub sij hawm txheej txheem ntawm lithium ion.

Nws txaus. , Zoo tshem tawm cov teebmeem ntawm polarization ntawm cov voj voog. Daim duab 1 Lub roj teeb muaj peev xwm attenuation thiab them thiab tso tawm kev ua tau zoo yog piv nrog 0.

5 magnification, tus nqi thiab tso tawm piv yog txo rau 0.02c, uas tsuas yog nce lub peev xwm khaws cia piv ntawm 181 thiab 575d roj teeb rau 0.8% thiab 1.

4%. Yog li ntawd, lub roj teeb muaj peev xwm attenuation tshwm sim los ntawm lub sij hawm ntev kub cia yog ib qho irreversible peev attenuation. Tsis tas li ntawd, nws tau pom tias lub amplitude ntawm lub roj teeb lub DC sab hauv kuj nce thiab tsis tseem ceeb, uas kuj qhia tau hais tias lub internal polarization ntawm lub roj teeb tsis yog ib qho tseem ceeb ua rau lub calendar cia roj teeb muaj peev xwm irreversible attenuation.

2. Battery Capacity Attenuation Mechanism Analysis Los soj ntsuam lub peev xwm ntawm lub roj teeb, lub roj teeb raug them rau 100% SOC lossis tawm mus rau 100% DOD tom qab 1C magnification. Kev soj ntsuam ntawm tus ncej dismantled los tshuaj xyuas qhov cuam tshuam ntawm qhov kub thiab txias cia ntawm cov qauv, cov khoom muaj pes tsawg leeg thiab cov khoom siv hluav taws xob ntawm cov yin thiab cov khoom siv tsis zoo.

Kev soj ntsuam immersion ntawm qhov sib txawv kub cia lub sij hawm roj teeb cathode swb nyob rau hauv 100% DOD XRD daim ntawv qhia. Piv nrog rau XRD tus qauv spectrum ntawm LifePO4 thiab FEPO4, tag nrho cov diffraction peaks ntawm lub ncov qaumteb qabteb swb sib raug, tsis muaj lwm yam theem. Daim duab 2 XRD spectrum ntawm lub roj teeb cathode ntawm qhov sib txawv cia lub sij hawm kub siab nco qab electrode daim ntawv electrochemical zog txo cov sij hawm sib txawv ntawm 100% SOC, nyob rau hauv uas cov electrode yog siv raws li cov electrode ua hauj lwm roj teeb, tsub nqi thiab paug xeem nrog 0.

1C magnification. Thawj qhov sib piv ntawm cov khoom siv cathode ntawm cov roj teeb sib txawv ntawm lub sijhawm khaws cia yog siab dua 155 mAh / g, thiab lub peev xwm tshwj xeeb ntawm cov khoom siv cathode yam tsis muaj lub roj teeb cia yog ze rau qhov chaw cia ntawm LIFEPO4 qauv yam tsis muaj kev puas tsuaj. Tus nqi hluav taws xob tas li ntawm lub roj teeb buckle hauv daim duab 3 (c) yog ntxiv me ntsis, tab sis tag nrho cov nqi them tseem nyob ze rau lub peev xwm tshwj xeeb ntawm cov khoom siv cathode yam tsis muaj lub roj teeb cia.

Lub polarization ntawm lub roj teeb cathode tom qab 575D tau nce, tab sis lub peev xwm lithium ntawm cov khoom siv cathode tsis cuam tshuam, thiab cov khoom siv electrolyte decomposition deposition hauv cov txheej txheem khaws cia yuav cuam tshuam. Fig. 3 yog lub roj teeb buckle nyob rau hauv uas tus nqi thiab tawm nkhaus ntawm lub roj teeb buckle yog sib sau ua ke los ntawm cov hluav taws xob sab hauv tsev ntawm lub roj teeb uas tsis tau daws yog los ntawm 181 thiab 575d, feem, nrog 335.

6 thiab 327.1 mAh / g, feem. Lub buckle roj teeb ntawm lub roj teeb uas khaws cia anode yog inveracted ua 0.

8% thiab 3.0%, qhia tias qhov kub thiab txias cia ntawm lithium graphite kuj tsawg heev. Rau lub roj teeb kev nyab xeeb kev pom, tag nrho cov nyiaj ntawm anode nyob rau hauv tag nrho cov roj teeb feem ntau tshaj 10% ntawm tag nrho cov cathode tag nrho muaj peev xwm, yog li lub anode irreversible muaj peev xwm attenuation tshwm sim los ntawm kub cia tsis cuam tshuam lub peev xwm ntawm tag nrho cov roj teeb.

Cia 181 thiab 575D Lub anode yog thawj tus nqi piv peev xwm ntawm qhov tsis muaj peev xwm ntawm 90.4% thiab 84.5% ntawm thawj tus nqi piv ntawm anode, raws li, thiab lub peev xwm tuav tus nqi ntawm lub roj teeb tiag tiag yog nyob ze.

Yog li, qhov laj thawj tseem ceeb rau lub roj teeb muaj peev xwm attenuation yog qhov poob ntawm cov lithium ions hauv txhua lub roj teeb. Hauv cov ntsiab lus, qhov kub thiab txias cia yuav tsis cuam tshuam rau qhov deintercalation ntawm LIFEPO4 thiab graphite electrodes. 100% DOD kub cia roj teeb Lub cathode ntawm ib tug pell yog muaj, qhov ua rau ntawm cov lithium ion muaj peev xwm txais tau cov anode tsis yog ib qho tseem ceeb hloov nyob rau hauv lub peev xwm delatically hloov cov active electrode khoom, tab sis vim lub roj teeb nyob rau hauv lub roj teeb.

Tus naj npawb ntawm ions ua tsawg. Lub active lithium ion nyob rau hauv lub roj teeb yog noj los ntawm lub electrode / electrolyte interface ntawm lub electrode / electrolyte interface, thiab cov hauv paus ntsiab lus ntawm lub active lithium ion poob yuav pab kom tob kev paub txog lub mechanism ntawm cia lub peev xwm poob. Polar micropatological tsom xam ntawm LifePO4 hais nyob rau hauv lub cathode nyob rau hauv lub cathode, particle loj yog hais txog 200 nm; Tom qab 181D cia, qhov tsis muaj qhov loj me ntawm LIFEPO4 hais tsis hloov pauv loj; Tom qab 575D cia, qhov sib txawv ntawm cov khoom yog txo qis.

Nyob rau hauv graphite anode, raws li lub sij hawm cia tau nce, tus nqi ntawm sab reactive khoom kuj hloov [Daim duab. 4 (d), (e), (f)]. Cov khoom siv sub-reactive nyob rau hauv cov txheej txheem kub khaws cia rau hauv tus ncej, thiab cov morphology ntawm tus ncej yog hloov.

Txhawm rau ua kom pom qhov cuam tshuam ntawm cov tshuaj tiv thaiv rau cov lus hais saum toj no active lithium ion poob, Li cov ntsiab lus hauv yin thiab txiv neej lub ntsiab lus tau txheeb xyuas ntxiv los kawm txog lub hauv paus ua rau lub zog lithium ion poob. Daim duab 4 Roj teeb ncej morphology rooj 1 yog ib qho kev xeem ICP-OES ntawm 100% SOC roj teeb yin anode. Kev hloov pauv hauv Li cov ntsiab lus hauv cathode tsis pom tseeb.

Cov ntsiab lus LI ntawm lub anode kuj tseem nyob rau tib theem, yog li tag nrho cov nqi ntawm cov yin thiab cov txwj laus ncej LI nyob rau hauv sib txawv cia lub sij hawm roj teeb yog tsis hloov. Table 1 Cov roj teeb sib txawv ntawm lub sijhawm cia (100% SOC) cov ntsiab lus ntawm cov ntsiab lus txij li 100% SOC roj teeb cathode daim ntawv muaj tsawg heev, qhov poob ntawm cov khoom siv lithium ion tseem ceeb rau kev tso nyiaj hauv anode. Nyob rau hauv 100% SOC siab kub cia, lub anode yog nyob rau hauv ib lub xeev uas lub potium nyob rau hauv lub xeev uas muaj peev xwm tsawg heev, thiab cov electrolyte yog yooj yim reacted ntawm nws nto, thiab lithium ions tau noj, thiab lithium-muaj cov khoom siv reactive.

Txhawm rau txiav txim siab qhov muaj pes tsawg leeg ntawm soluble lithium nto ntawm lub anode, lub dismantling ntawm 100% DOD roj teeb yog titrated, thiab cov txiaj ntsig tau qhia hauv Table 2. Table 2100% DOD roj teeb Anode soluble lithium tsim cov anode nto nyob rau hauv ib tug carbonate morphology, uas yog incremented raws li lub sij hawm cia yog ncua (saib Table 2), qhia hais tias lub roj teeb cia txheej txheem tsim ib tug loj tus naj npawb ntawm inorganic lithium ntsev Cheebtsam. Cov ntsev inorganic yog ib yam khoom tseem ceeb ntawm cov kuab tshuaj txo cov tshuaj tiv thaiv, uas yog tshwm sim los ntawm ntau qhov decomposition ntawm electrolyte thaum lub roj teeb cia.

Electrode Reaction Dynamics Electrochemical Exhaust Spectroscopy (saib daim duab 5), txawm hais tias lub cathode RCT nce nrog lub sij hawm cia kub kub [Daim duab 5. 5 (a)], tab sis lub cathode RCT yog me dua, lub sab hauv ntawm lub roj teeb kuj yog me me. Anode EIS [Fig.

5 (b)] RSEi tsis pom tseeb nrog lub sijhawm khaws cia, tab sis RCT txuas ntxiv nrog lub sijhawm khaws cia. Vim tias qhov tso tawm ntawm cov khoom siv electrolyte sub-reaction thaum lub sij hawm kub cia, qhov anode piv cheeb tsam ntawm qhov chaw txo nrog lub sij hawm cia, thiab cov anode tshwj xeeb nto ntawm 0, 181 thiab 575d roj teeb yog 3.42, 2.

97 thiab 1.84cm2 / g. Qhov anode piv ntawm thaj chaw txo qis cov tshuaj tiv thaiv electrochemical uas tshwm sim ntawm qhov chaw ntawm lub anode, uas ua rau muaj kev nce nqi hloov pauv tsis kam RCT ntawm qhov chaw ntawm anode / electrolyte.

Fig. 5 yog piav nyob rau hauv lub electrochemical impedance spectrum ntawm lub buckle roj teeb. Thaum lub sij hawm kub ceev txheej txheem, lub lithium lub xeev anode nyob rau hauv ib tug tsis tshua muaj peev xwm lub xeev, thiab cov electrolyte txo cov tshuaj tiv thaiv noj active lithium ions, thiab thaum kawg generates ib inorganic lithium ntsev; kub siab ntxiv electrolysis Ua kua txo cov tshuaj tiv thaiv, ua kom muaj ntau ntawm lithium ion (Daim duab 6).

Tsis tas li ntawd, lub anode sab reactive khoom deposits, SEI zaj duab xis yog thickened, uas ua rau deterioration ntawm electrode kinetic kev ua tau zoo. Daim duab 6, lub peev xwm attenuation tshuab tau qhia. 3.

Lub roj teeb kub kub cia kev ua tau zoo Txhim kho vim muaj peev xwm poob hauv lub roj teeb qhov kub thiab txias cia txheej txheem tseem ceeb lithium ion poob los ntawm sab kev cuam tshuam los ntawm qhov chaw ntawm lub anode, Txij li thaum ntxiv SEI zaj duab xis thermally stabilizing additives (ASR) tuaj yeem txhim kho qhov kub siab stability ntawm SEI zaj duab xis, txo cov sab reactivity ntawm lub anode, txo cov active lithium ions. Daim duab 7 Sib txawv electrolyte roj teeb cia nkhaus thiab SEI membrane thermostability infrastructure ntxiv 1% ASR tuaj yeem txhim kho lub siab kub cia lub neej ntawm lub roj teeb. Tom qab ntxiv 1% ASR, 575D peev xwm tuav tau nce los ntawm 85.

8% mus rau 87.5% [Daim duab 7 (a)]. DCR Rolling Rate yog qhov qis dua li ntawm lub hauv paus electrolyte, thiab cov ntsiab lus ntawm cov anode soluble lithium-muaj cov compound kuj tau txo qis (Table 3).

DSC tsom xam yog ua ntawm 100% SOC roj teeb anode [Figs. 7 (b)], kev nqus cua sov siab tshaj 100 ° C rau cov kuab tshuaj residual. Table 3 Ua ntej anode soluble lithium 100% DOD roj teeb, anode soluble lithium ntxiv, thiab anode 90 ° C pib exotherm, uas yog decomposed rau anode nto SEI; Tom qab ntxiv ASR, qhov decomposition kub yog nce mus rau 101 ° C.

Tom qab ntxiv ASR, qhov thermal stability ntawm SEI yog qhov zoo dua, thiab cov lithium ion poob tuaj yeem txo qis, thiab lub roj teeb cia lub neej tuaj yeem txhim kho. Thib peb, qhov kawg kev txiav txim siab soj ntsuam cov khoom siv hluav taws xob electrochemical, polar physics thiab cov khoom siv hluav taws xob ntawm cov khoom lag luam phosphate ion roj teeb kub cia, thiab pom tias lub roj teeb muaj peev xwm poob hauv qhov kub thiab txias yog qhov tseem ceeb los ntawm anode txo electrolyte nyob rau hauv tsis tshua muaj peev xwm. , ua rau muaj zog lithium ion poob.

Lub sub-reactive khoom ntawm anode txo electrolyte yog tso rau hauv ib qho anode, thiab cov inorganic tivthaiv nyob rau hauv cov deposit hinders lithium ion diffusion, thiaj li hais tias cov anode cov tshuaj tiv thaiv kinetics txo. Los ntawm kev ntxiv SEI membrane thermostability nyob rau hauv cov electrolyte zoo txhim kho thermal stability ntawm SEI zaj duab xis, txo qhov txo cov tshuaj tiv thaiv ntawm cov electrolyte, txo cov active lithium ion noj, thiab txhim kho kub cia lub neej.