Lithium roj teeb kom them ceev

Txais daim duab no ua piv txwv qhia tus txheej txheem roj teeb, qhov abscissa yog lub sijhawm thiab kev teem caij yog qhov hluav taws xob. Yuav muaj cov txheej txheem them ua ntej tam sim no thaum pib ntawm lub roj teeb lithium, uas yog, CC Ua Ntej Them, lub hom phiaj yog tswj lub zog cov khoom zoo thiab tsis zoo. Tom qab ntawd, tom qab lub roj teeb lub xeev tau ruaj khov, nws tuaj yeem hloov kho rau cov kev them nqi tam sim no, uas yog, CC Fast Charge. Thaum kawg, sau hom hluav taws xob tas li them hom (CV). Rau cov roj teeb lithium, lub kaw lus pib qhov hluav taws xob tas mus li them nqi tom qab pom tias qhov hluav taws xob ncav cuag 4.2V, lub txim them tam sim no maj mam txo, thiab lub txim them tas thaum nws qis dua tus nqi.

Hauv tag nrho cov txheej txheem, cov roj teeb sib txawv nyias muaj nyias cov roj teeb sib xws. Piv txwv, cov roj teeb txheem rau 3C cov khoom siv feem ntau 0.1C-0.5C, thiab rau cov roj teeb hluav taws xob muaj zog, cov qauv them tseem muaj feem ntau 1C. Xaiv lub qis them hluav taws xob tam sim no kuj xav txog kev nyab xeeb ntawm lub roj teeb. Yog li no, kev niaj hnub them ceev ceev yog hais txog qhov them tawm tam sim no uas yog ob peb zaug txog kaum zaus ntawm qhov siab dua li cov qauv them tam sim no.

Qee tus neeg hais tias them lub roj teeb lithium yog zoo li hliv npias. Nws' s nrawm thiab nqa nrog npias, tab sis nws muaj npuas dej ntau dua. Cov ncuav yog qeeb thiab qeeb, tab sis muaj npias ntau, uas yog tiag tiag. Thaum lub sijhawm them ceev ceev txuag lub sijhawm them, nws tseem yuav ua kev puas tsuaj ntau dua rau lub roj teeb nws tus kheej. Vim muaj qhov tshwm sim pom tseeb hauv lub roj teeb, qhov siab tshaj plaws them nyiaj tam sim no uas nws tuaj yeem lees txais yuav txo nrog qhov nce ntawm qhov them nyiaj thiab tawm mus los. Thaum lub txim them txuas txuas ntxiv thiab qhov tam sim no lub txim loj, qhov ion siab ntawm qhov hluav taws xob yuav nce ntxiv, thiab qhov kev hloov pauv rau ntau dua. Lub davhlau taws xob voltage tsis tuaj yeem ncaj qha ncaj ncaj rau cov nqi raug hluav taws xob / lub zog. Nyob rau tib lub sijhawm, thaum them nrog lub siab tam sim no, qhov nce ntawm kev tawm tsam sab hauv yuav ua rau Joule cua sov ua haujlwm (Q=I2Rt), thiab ua rau cov kev tawm sab, xws li cov tshuaj tiv thaiv hluav taws xob tsis zoo ntawm electrolyte, kev tsim cov khoom siv roj thiab cov teeb meem teeb meem. Qhov kev pheej hmoo tshwm sim sai dua, uas yuav cuam tshuam kev nyab xeeb ntawm lub roj teeb. Kev muaj peev xwm, lub neej ntawm roj teeb tsis muaj hluav taws xob yuav dhau los ua luv luv.

01 Cathode khoom siv

Cov txheej txheem ntawm kev them ceev ceev ntawm cov roj teeb lithium yog txheej txheem ntawm kev tsiv sai ntawm Li + hauv cov khoom siv electrode zoo rau hauv qhov tsis zoo electrode. Lub particle qhov loj ntawm cov khoom siv zoo electrode tuaj yeem cuam tshuam rau lub sijhawm teb ntawm cov roj teeb electrochemical txheej txheem, txoj kev tsis sib xws ntawm ions, thiab lwm yam Raws li kev tshawb fawb, raws li cov noob nplej loj ntawm cov khoom poob, lub diffusion coefficient ntawm lithium ions nce. Txawm li cas los xij, thaum lub particle loj ntawm cov khoom txo, yuav muaj teeb meem loj hauv cov khoom tsim khoom lag luam, ua rau muaj qhov tsis sib xws. Nyob rau tib lub sijhawm, nanoparticles yuav txo qhov ceev kev sib xyaw ntawm cov ncej daim thiab tiv tauj lub tshuab hluav taws xob thaum lub sijhawm them thiab tawm txheej txheem. Qhov chaw nce thiab qhov tshwm sim cuam tshuam cuam tshuam rau kev ua haujlwm ntawm lub roj teeb.

Ib txoj hauv kev ntxiv kom zoo dua yog txheej thiab hloov kho qhov zoo ntawm cov khoom siv electrode. Piv txwv li, qhov conductivity ntawm LFP nws tus kheej tsis zoo heev. Tom qab saum npoo yog coated nrog cov khoom siv carbon lossis lwm yam khoom siv, nws txoj kev coj ua tau zoo tuaj, uas tau txais txiaj ntsig los txhim kho qhov them ceev ntawm lub roj teeb. kev ua tau zoo.

02 Cov khoom siv Anode

Kev them nyiaj sai ntawm lithium roj teeb txhais tau tias lithium ions tau sai sai thiab" ua luam dej" rau qhov tsis zoo electrode. Lub sijhawm no, cov khoom siv tsis zoo electrode yuav tsum muaj lub peev xwm los ntxig lithium. Cov khoom siv anode siv rau kev them nrawm ntawm cov roj teeb lithium suav nrog cov khoom siv carbon, lithium titanate thiab lwm cov ntaub ntawv tshiab.

Rau cov khoom siv carbon, vim tias qhov muaj peev xwm ntawm lithium kev tso tawm zoo ib yam li lub peev xwm ntawm lithium nag lossis daus, nyob rau hauv cov ntaub ntawv ntawm cov pa hluav taws xob, lithium ions feem ntau nyiam tso rau hauv graphite, tab sis nyob rau hauv ceev ceev them lossis tsis kub muaj peev xwm, lithium ions yuav los nag nyob rau ntawm nto rau tsim dendritic lithium. Dendrite lithium thiav cov SEI, ua rau kom poob ntawm Li + thiab txo cov roj teeb muaj peev xwm. Thaum cov roj ntsha lithium ncav cuag ib qho nyiaj, nws yuav loj hlob los ntawm qhov hluav taws xob tsis zoo mus rau lub tshuab cais tawm, ua rau muaj kev pheej hmoo ntawm luv luv hauv lub roj teeb.

Rau LTO, nws yog" xoom mas" cov pa oxygen muaj cov khoom siv hluav taws xob tsis zoo, uas tsis tsim cov khoom siv SEI thaum lub roj teeb ua haujlwm, thiab muaj lub zog sib khi nrog cov roj ntsha lithium, uas tuaj yeem ua tau raws li qhov yuav tsum tau ua kom ceev thiab ceev nrawm. Nyob rau tib lub sijhawm, nws yog qhov tseeb vim tias SEI tsis tuaj yeem tsim, cov khoom siv tsis zoo electrode yuav ncaj qha mus rau electrolyte, uas txhawb nqa qhov tshwm sim ntawm kev tsis haum. Cov roj teeb meem ntawm LTO cov roj teeb tsis tuaj yeem daws tau ntev thiab tsuas yog kho tau los ntawm kev hloov kho saum npoo.

03 Cov hluav taws xob tov

Raws li tau hais ua ntej, vim muaj qhov tsis sib haum ntawm lithium ion tsiv teb tsaws khiav ceev thiab hluav taws xob sib kis tau thaum lub sij hawm them ceev, lub roj teeb yuav muaj ntau qhov sib txawv. Yog li yuav kom txo qis cov kev tsis zoo tshwm sim los ntawm roj teeb kev sib tsoo, peb lub ntsiab lus hauv qab no yuav ua qhov kev taw qhia ntawm kev tshawb fawb electrolyte thiab kev txhim kho: 1. Muaj kev sib cais siab kawm electrolyte ntsev; 2. Hnyav hnyav recombination-qis viscosity; 3. Kev sib cuam tshuam tswj-membrane impedance qis dua.

04 Kev sib raug zoo ntawm kev tsim thev naus laus zis thiab kev them ceev ceev

Yav dhau los, qhov yuav tsum tau thiab qhov tshwm sim ntawm kev them nyiaj ceev tau txheeb xyuas los ntawm peb cov ntaub ntawv tseem ceeb, xws li cov ntaub ntawv zoo thiab tsis zoo electrode thiab cov kua hluav taws xob. Hauv qab no yog cov txheej txheem kev tsim qauv uas muaj qhov cuam tshuam loj. Lub roj teeb txheej txheem tsim cov kev cuam tshuam ncaj qha rau kev tsiv ntawm lithium ions nyob rau ntau qhov chaw ntawm lub roj teeb ua ntej thiab tom qab lub roj teeb tau qhib, yog li cov roj teeb txheej txheem tsim muaj qhov cuam tshuam tseem ceeb rau kev ua haujlwm ntawm lub lithium ion roj teeb.

(1) Slurry

Hais txog cov yam ntxwv ntawm cov slurry, ib qho kev xav yog kom muaj kev sib cais sib npaug ntawm tus neeg saib xyuas tus neeg ua haujlwm. Vim tias tus neeg sawv cev ntawm tus neeg xa xov xwm tseem ceeb faib rau cov khoom sib txuam, qhov sib txuas sib luag ntawm cov khoom sib txuas tau tsim los ntawm cov khoom siv nquag thiab nruab nrab ntawm cov khoom siv nquag thiab tus neeg khaws khoom tam sim no, uas muaj cov haujlwm ntawm kev khaws cov micro tam sim no, txo kev tiv tauj, thiab nce qhov ceev ntawm hluav taws xob. Cov. Lwm cov nam yog los tiv thaiv tshaj-dispersion ntawm tus neeg saib xyuas conductive. Thaum lub sijhawm them tus nqi thiab tawm txheej txheem, cov qauv siv lead ua ntawm cov ntaub ntawv zoo thiab tsis zoo yuav hloov, uas yuav ua rau tus neeg ua hauj lwm conductive nti tawm, ua kom muaj peev txheej sab hauv lub roj teeb, thiab cuam tshuam rau kev ua haujlwm.

(2) Pole daim cheeb tsam ntom ntom

Hauv txoj kev xav, hom roj teeb thiab cov roj teeb muaj peev xwm tsis tuaj yeem muaj ob qho tib si. Thaum cov nplaim ntom ntawm cov ncej zoo thiab qhov tsis zoo yog qhov tsawg, qhov tsis sib haum ntawm lithium ions tuaj yeem nce ntxiv, thiab qhov tsis kam ntawm ion thiab hluav taws xob tsiv tuaj yeem txo. Qhov qis qis qis tshaj ntawm cov leeg, qhov sib txawv me me ntawm qhov seem ncej, thiab qhov kev hloov pauv me me hauv cov qauv ntawm tus ncej uas tshwm sim los ntawm cov kab txuas ntxiv thiab rho tawm ntawm lithium ions thaum them nyiaj thiab tawm. Txawm li cas los xij, yog tias qhov ntsuas hluav taws xob ua kom qis dhau, lub zog hluav taws xob ntawm lub roj teeb yuav raug txo thiab tus nqi yuav nce ntxiv, yog li kev txiav txim siab dav ntawm cov cua sov yuav tsum tau ua. Daim duab hauv qab no yog ib qho piv txwv ntawm 6C them thiab 1C tso tawm ntawm lithium cobalt oxide roj teeb, koj tuaj yeem pom:

(3) Qhov sib txawv ntawm ncej daim txheej

Ib tug phooj ywg nug ua ntej, puas tsis sib xws sab npoo ntawm tus ncej yuav cuam tshuam rau lub roj teeb? Los ntawm txoj kev, rau kev ua kom ceev ntawm kev ua tiav, nws yog qhov tseem ceeb yog qhov sib xws ntawm qhov tsis zoo ncej thooj. Yog tias qhov nplaim deg ntawm cov hluav taws xob tsis zoo yog qhov tsis xwm yeem, tom qab dov, sab hauv porosity ntawm cov khoom siv nquag yuav sib txawv. Qhov sib txawv ntawm qhov porosity yuav ua rau muaj qhov sib txawv ntawm cov khoom xa tawm sab hauv tam sim no, cuam tshuam rau qhov tsim thiab kev ua tiav ntawm SEI hauv cov roj teeb tsim theem, thiab thaum kawg cuam tshuam rau kev them nqi ceev ntawm lub roj teeb.

(4) Kev sib xyaw ua ke ntawm tus ncej

Vim li cas thiaj yuav tsum tau muab cov thooj ncej ua ke? Ib qho yog los txhim kho qhov tshwj xeeb ntawm lub roj teeb, thiab lwm qhov yog los txhim kho lub roj teeb ua haujlwm. Cov khoom siv hluav taws xob sib txawv muaj qhov sib txawv hauv kev pom zoo. Ua kom muaj qhov ua tiav ntawm kev sib xyaw ua ke, qhov me me ntawm qhov ntxeem tau ntawm cov electrode ncej daim, nruj dua qhov kev sib txuas ntawm cov lus, thiab qhov tsawg dua qhov tuab ntawm tus ncej txuas hauv tib qhov kev ntom ntom, yog li txo txoj kev tsiv teb chaws ntawm lithium ions. Thaum lub compaction ceev yog siab dhau lawm, cov electrolyte infiltration effect tsis zoo, uas yuav ua rau cov khoom teeb meem thiab kev xa khoom ntawm tus neeg sawv cev faib tawm, thiab cov teeb meem cua yuav tshwm sim tom qab. Tib yam yog 6C them ntawm lithium cobalt oxide roj teeb 1C kev cuam tshuam, qhov cuam tshuam ntawm kev cog lus tuab ntawm kev tso tawm lub peev xwm tshwj xeeb muaj raws li hauv qab no:

05 Tshuaj lom neeg laus thiab lwm tus

Rau cov pa roj carbon anode roj teeb, tsim-laus yog txheej txheem tseem ceeb rau lithium roj teeb, thiab cov txheej txheem no yuav cuam tshuam rau qhov zoo ntawm SEI. Qhov tsis tuab tuab lossis cov qauv tsis ruaj khov ntawm tus SEI yuav cuam tshuam lub peev xwm ceev ceev them thiab lub neej ntawm lub roj teeb.

Ntxiv nrog rau ntau yam tseem ceeb saum toj no, kev tsim cov xov tooj ntawm tes thiab kev them nqi thiab kev tsim tawm lub tshuab yuav muaj kev cuam tshuam loj dua rau kev ua haujlwm ntawm cov roj teeb lithium. Raws li lub sijhawm siv sijhawm ntev, roj teeb kev them tus nqi yuav tsum txo kom tsawg, txwv tsis pub nws yuav nce polarization.

Xaus

Lub ntsiab lus ntawm kev them sai thiab tshem tawm ntawm cov roj teeb lithium yog tias lithium ions tuaj yeem muab rho tawm sai ntawm cov ntaub ntawv zoo thiab tsis zoo. Cov khoom siv roj teeb lub zog, cov txheej txheem tsim, thiab kev them thiab tawm lub zog yuav txhua qhov cuam tshuam ntawm kev them lub tshuab hluav taws xob tam sim no. Cov txheej txheem ruaj khov ntawm cov ntaub ntawv zoo thiab tsis zoo electrode yuav tsis ua rau cov txheej txheem vau tawg thaum cov txheej txheem tshem tawm cov roj ntsha lithium sai, thiab cov lithium ions diffuse sai dua ntawm cov khoom siv kom tiv qhov siab them tam sim no. Vim muaj qhov tsis sib xws ntawm ion khiav ceev thiab hluav taws xob kis tus nqi, polarization yuav tshwm sim thaum them nyiaj thiab tawm. Nws yog qhov tsim nyog los txo qis polarization ntau li ntau tau los tiv thaiv nag lossis daus ntawm lithium hlau thiab txo qhov muaj peev xwm cuam tshuam rau lub neej.