Lithium-ion roj teeb Anode cov ntaub ntawv

Raws li ib qho ntawm cov ntaub ntawv tseem ceeb rau cov roj teeb lithium-ion, cov ntaub ntawv anode yuav tsum tau ua kom tau raws li ntau yam kev mob.

• Li intercalation thiab deintercalation cov tshuaj tiv thaiv muaj qhov tsis tshua muaj peev xwm redox kom txaus siab rau qhov tso zis hluav taws xob siab ntawm lithium-ion roj teeb.
• Thaum lub sij hawm tus txheej txheem ntawm Li intercalation thiab deintercalation, lub electrode tej zaum yuav hloov me ntsis, uas yog zoo rau lub roj teeb kom tau ib tug ruaj khov kev khiav hauj lwm voltage.
• Loj reversible peev xwm kom tau raws li lub zog siab ceev ntawm lithium-ion roj teeb.
• Kev ruaj ntseg zoo thaum lub sij hawm Li deintercalation txheej txheem, kom lub roj teeb muaj lub neej voj voog siab.
• Ib puag ncig tus phooj ywg, tsis muaj ib puag ncig muaj kuab lom lossis lom hauv kev tsim khoom thiab pov tseg roj teeb.
• Cov txheej txheem kev npaj yog yooj yim thiab tus nqi qis, cov peev txheej muaj ntau thiab yooj yim kom tau, thiab lwm yam.

Nrog kev txhim kho thev naus laus zis thiab kev txhim kho kev lag luam, cov khoom siv anode kuj tseem nce ntxiv, thiab cov ntaub ntawv tshiab tau tshawb pom tas li.

Cov khoom siv anode tuaj yeem muab faib ua cov pa roj carbon thiab tsis yog carbon. Carbon muaj xws li ntuj graphite, dag graphite, mesophase carbon microspheres, nyuaj carbon, mos carbon, thiab lwm yam. Tsis yog-carbon pawg muaj xws li silicon-raws li cov ntaub ntawv, titanium-raws li cov ntaub ntawv, tin-raws li cov ntaub ntawv, lithium hlau, thiab lwm yam.

1. Ntuj graphite

Ntuj graphite feem ntau muab faib ua flake graphite thiab microcrystalline graphite. Flake graphite nthuav tawm ntau dua rov qab muaj peev xwm thiab thawj lub voj voog Coulombic efficiency, tab sis nws lub voj voog ruaj khov me ntsis. Microcrystalline graphite muaj lub voj voog zoo ruaj khov thiab kev ua haujlwm zoo, tab sis nws cov Coulombic efficiency tsawg nyob rau thawj lub lim tiam. Ob lub graphites ntsib teeb meem ntawm lithium nag lossis daus thaum lub sijhawm them ceev.

Rau flake graphite, txheej, compounding thiab lwm txoj kev yog tsuas yog siv los txhim kho lub voj voog stability thiab thim rov qab muaj peev xwm ntawm phosphorus flake graphite. Tsis tshua muaj kub ua rau Li + diffuse maj mam nyob rau hauv phosphorus flake graphite, uas ua rau tsawg reversible peev xwm ntawm phosphorus flake graphite. Pore ​​creation tuaj yeem txhim kho nws qhov kub thiab txias lithium cia kev ua haujlwm.

Qhov tsis zoo crystallinity ntawm microcrystalline graphite ua rau nws lub peev xwm qis dua li ntawm flake graphite. Compounding thiab txheej yog feem ntau siv txoj kev hloov kho. Li Xinlu thiab lwm tus coated nto ntawm microcrystalline graphite nrog phenolic resin thermally tawg carbon, ua rau Coulombic efficiency ntawm microcrystalline graphite los ntawm {{0}}.2% mus rau 89.9%. Ntawm qhov ceev tam sim no ntawm 0.1C, nws qhov kev tso tawm tshwj xeeb tsis tuaj yeem lwj tom qab 30 lub voj voog them nqi. Sun YL et al. embedded FeCl3 ntawm cov khaubncaws sab nraud povtseg ntawm microcrystalline graphite kom nce lub peev xwm thim rov qab ntawm cov khoom mus rau ~ 800 mAh g-1. Lub peev xwm thiab kev ua tau zoo ntawm microcrystalline graphite yog qhov phem dua li ntawm phosphorus flake graphite, thiab muaj cov kev tshawb fawb tsawg dua piv rau phosphorus flake graphite.

2. Artificial graphite

Artificial graphite yog tsim los ntawm cov khoom siv raw xws li roj av coke, koob coke, thiab pitch coke los ntawm crushing, granulation, kev faib tawm, thiab kev ua haujlwm kub graphitization. Artificial graphite muaj qhov zoo hauv kev ua haujlwm ntawm lub voj voog, kev ua haujlwm zoo, thiab kev sib raug zoo nrog cov electrolytes, tab sis nws lub peev xwm feem ntau qis dua li ntuj graphite, yog li qhov tseem ceeb uas txiav txim siab nws tus nqi yog lub peev xwm.

Txoj kev hloov kho ntawm cov khoom graphite sib txawv ntawm cov graphite ntuj. Feem ntau, lub hom phiaj ntawm kev txo cov graphite grain orientation (OI tus nqi) yog ua tiav los ntawm kev hloov kho ntawm cov qauv particle. Feem ntau, ib rab koob coke precursor nrog txoj kab uas hla ntawm 8 mus rau 10 μm yog xaiv, thiab cov ntaub ntawv yooj yim graphitizable xws li suab yog siv los ua cov pa roj carbon monoxide, thiab tau ua tiav hauv lub tshuab ziab khaub ncaws. Ob peb rab koob coke yog sib koom ua ke los tsim cov khoom sib txuas nrog cov particle loj D50 txij li 14 mus rau 18 μm, thiab tom qab ntawd graphitization tiav, txo qis OI tus nqi ntawm cov khoom.

3. Mesophase carbon microspheres

Thaum asphalt tebchaw raug kho cua sov, cov tshuaj tiv thaiv thermal polycondensation tshwm sim los tsim cov anisotropic mesophase spheres me me. Cov khoom siv micron-loj spherical carbon tsim los ntawm kev sib cais cov hlaws mesophase los ntawm asphalt matrix hu ua mesophase carbon microspheres. Txoj kab uas hla feem ntau yog nruab nrab ntawm 1 thiab 100 μm. Txoj kab uas hla ntawm kev lag luam mesophase carbon microspheres feem ntau yog nruab nrab ntawm 5 thiab 40 μm. Lub pob saum npoo yog du thiab muaj lub siab compaction ceev.

Qhov zoo ntawm mesophase carbon microspheres:

(1) Spherical particles yog tsim los ntawm high-density stacked electrode coatings, thiab muaj ib tug me me qhov chaw deg, uas yog conducive rau txo cov kev xav ntawm sab.

(2) Cov pa roj carbon atomic txheej hauv lub pob yog txheej txheem radially, Li + yog ib qho yooj yim rau intercalation thiab deintercalation, thiab cov nqi tam sim no loj thiab kev ua haujlwm tawm tau zoo.

Txawm li cas los xij, rov qab intercalation thiab deintercalation ntawm Li + ntawm cov npoo ntawm mesocarbon microspheres tuaj yeem yooj yim ua rau tev thiab deformation ntawm cov pa roj carbon txheej, ua rau muaj peev xwm fading. Cov txheej txheem txheej txheej saum npoo tuaj yeem cuam tshuam qhov tshwm sim ntawm tev tawm. Tam sim no, feem ntau kev tshawb fawb ntawm mesophase carbon microspheres tsom rau kev hloov kho saum npoo, sib xyaw nrog lwm cov ntaub ntawv, txheej txheej, thiab lwm yam.

4. Mos carbon thiab hard carbon

Mos carbon yog yooj yim graphitizable carbon, uas yog hais txog amorphous carbon uas yuav graphitized ntawm kub siab tshaj 2500 degree. Mos carbon muaj crystallinity tsawg, me me grain loj, loj interplanar spacing, zoo compatibility nrog electrolyte, thiab zoo npaum li cas. Cov pa roj carbon monoxide muaj qhov muaj peev xwm hloov tsis tau thaum lub sij hawm thawj zaug thiab tso tawm, qhov tso zis hluav taws xob tsawg, thiab tsis muaj peev xwm them nqi thiab tawm platform. Yog li ntawd, feem ntau nws tsis yog siv nws tus kheej raws li cov khoom siv tsis zoo electrode, tab sis feem ntau yog siv los ua cov txheej los yog cov khoom siv tsis zoo electrode.

Hard carbon yog carbon uas nyuaj rau graphitize thiab feem ntau yog tsim los ntawm thermal tawg ntawm cov ntaub ntawv polymer. Cov pa roj carbon zoo xws li cov roj carbon resin, organic polymer pyrolytic carbon, carbon dub, biomass carbon, thiab lwm yam. Cov khoom siv carbon no muaj cov qauv ntxeem tau, thiab tam sim no ntseeg tias nws tsuas yog khaws cov lithium los ntawm Li + reversible adsorption / desorption hauv micropores thiab nto. adsorption / tshem tawm.

Lub peev xwm thim rov qab tshwj xeeb ntawm cov roj carbon nyuaj tuaj yeem ncav cuag 300 ~ 500mAhg -1, tab sis qhov nruab nrab redox voltage siab li ~ 1Vvs.Li + / Li, thiab tsis muaj qhov pom tseeb voltage platform. Txawm li cas los xij, cov pa roj carbon monoxide muaj qhov muaj peev xwm ua kom tsis muaj peev xwm rov qab tau zoo, lagging voltage platform, qis compaction ceev, thiab cov roj tsim tau yooj yim, uas kuj yog nws qhov tsis zoo uas tsis tuaj yeem tsis quav ntsej. Kev tshawb fawb nyob rau xyoo tas los no tau tsom mus rau kev xaiv cov khoom sib txawv ntawm cov pa roj carbon monoxide, kev tswj cov txheej txheem, kev sib xyaw nrog cov khoom muaj peev xwm, thiab txheej txheej.

5. Cov khoom siv silicone

Txawm hais tias graphite anode cov ntaub ntawv muaj qhov zoo ntawm kev ua haujlwm siab thiab ruaj khov, lawv txoj kev loj hlob ntawm lub zog ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom ntom (372mAh / g). Silicon yog suav hais tias yog ib qho ntawm cov khoom siv zoo tshaj plaws anode, nrog rau qhov theoretical gram muaj peev xwm txog li 4200mAh / g, uas yog ntau dua 10 npaug ntau dua li cov khoom siv graphite. Nyob rau tib lub sijhawm, lub peev xwm ntawm lithium insertion ntawm Si yog siab dua li cov khoom siv carbon, yog li qhov kev pheej hmoo ntawm lithium nag lossis daus thaum them nyiaj yog me me thiab nyab xeeb dua. Txawm li cas los xij, cov khoom siv silicon anode yuav dhau los ua qhov ntim ntawm ze li ntawm 300% thaum lub sij hawm txheej txheem ntawm intercalation thiab deintercalation lithium, uas zoo heev txwv kev lag luam daim ntawv thov ntawm silicon anodes.

Silicon-raws li anode cov ntaub ntawv feem ntau muab faib ua ob pawg: silicon-carbon anode cov ntaub ntawv thiab silicon-oxygen anode cov ntaub ntawv. Cov kev taw qhia tseem ceeb tam sim no yog siv graphite ua cov matrix, suav nrog 5% mus rau 10% pawg ntawm nano-silicon lossis SiOx los tsim cov khoom sib xyaw, thiab coated nrog cov pa roj carbon monoxide los tiv thaiv cov khoom hloov pauv thiab txhim kho lub voj voog stability.

Kev txhim kho lub peev xwm tshwj xeeb ntawm cov khoom tsis zoo electrode yog qhov tseem ceeb rau kev ua kom lub zog ceev. Tam sim no, daim ntawv thov tseem ceeb yog graphite-raws li cov ntaub ntawv, nws lub peev xwm tshwj xeeb tau tshaj nws qhov peev xwm theoretical siab txwv (372mAh / g). Silicon cov ntaub ntawv ntawm tib tsev neeg muaj lub siab tshaj plaws theoretical lub peev xwm (txog 4200mAh / g), uas yog ntau tshaj 10 npaug ntawm graphite. Nws yog ib qho ntawm cov lithium roj teeb anode cov ntaub ntawv nrog rau daim ntawv thov kev cia siab.

Tam sim no, silicon-raws li anode thev naus laus zis uas tuaj yeem ua lag luam tau muab faib ua ob pawg. Ib qho yog silica, uas feem ntau muab faib ua peb tiam: 1st tiam silica (silicon oxide), 2nd tiam pre-magnesium silica, thiab 3rd tiam pre-lithium silica. Qhov thib ob yog silicon carbon, uas feem ntau muab faib ua ob tiam: thawj tiam yog xuab zeb-av nano silicon tov nrog graphite. Generation 2: CVD txoj kev tso nyiaj nano-silica mus rau cov pa roj carbon monoxide.

6. Lithium titanate

Lithium titanate (LTO) yog cov khoom sib xyaw oxide tsim los ntawm cov hlau lithium thiab tsis tshua muaj peev xwm hloov pauv hlau titanium. Nws belongs rau spinel hom khoom tov ntawm AB2X4 series. Lub peev xwm theoretical gram ntawm lithium titanate yog 175mAh / g, thiab qhov tseeb gram muaj peev xwm ntau dua 160mAh / g. Nws yog ib qho ntawm cov khoom siv anode tam sim no. Txij li thaum lithium titanate tau tshaj tawm hauv xyoo 1996, cov kev kawm hauv zej zog tau zoo siab txog nws txoj kev tshawb fawb. Cov ntawv tshaj tawm ntxov tshaj plaws ntawm kev lag luam tuaj yeem taug qab mus rau 4.2Ah lithium titanate anode fais fab roj teeb tso tawm los ntawm Toshiba hauv xyoo 2008, nrog rau qhov nominal voltage ntawm 2.4V thiab lub zog ceev ntawm 67.2Whkg-1 (131.6WhL{{16} }).

Qhov zoo:

(1) Zero strain, lithium titanate unit cell parameter a =0.836nm, intercalation thiab deintercalation ntawm lithium ions thaum lub sij hawm them thiab tso tawm yuav luag tsis muaj kev cuam tshuam rau nws cov qauv siv lead ua, zam kev hloov pauv ntawm cov khoom siv nthuav dav thiab kev cog lus thaum them nqi thiab tso tawm. Yog li ntawd, nws muaj kev ruaj ntseg electrochemical siab heev thiab lub neej voj voog.

(2) Tsis muaj kev pheej hmoo ntawm lithium nag lossis daus. Lub peev xwm lithium ntawm lithium titanate yog siab li 1.55V. Tsis muaj SEI zaj duab xis yog tsim thaum lub sij hawm thawj tus nqi. Nws muaj kev ua haujlwm siab thawj zaug, zoo thermal stability, tsis tshua muaj kev cuam tshuam impedance, thiab zoo heev uas tsis tshua muaj nqi them nqi. Nws tuaj yeem raug them ntawm -40 degree .

(3) Peb-dimensional ceev ion conductor. Lithium titanate muaj peb-dimensional spinel qauv. Qhov chaw rau lithium insertion yog ntau dua qhov sib nrug ntawm graphite txheej. Lub ionic conductivity yog ib qho kev txiav txim ntawm qhov loj dua li cov khoom siv graphite. Nws yog tshwj xeeb tshaj yog haum rau high-rate them thiab tso tawm. Txawm li cas los xij, nws lub peev xwm tshwj xeeb thiab lub zog tshwj xeeb yog qhov tsawg, thiab cov txheej txheem them nyiaj thiab tso tawm yuav ua rau cov electrolyte decompose thiab tsam plab.

Tam sim no, kev lag luam ntim ntawm lithium titanate tseem tsawg heev, thiab nws cov txiaj ntsig ntawm graphite tsis pom tseeb. Txhawm rau txhawm rau txo qis qhov tshwm sim ntawm qhov tshwm sim ntawm lithium titanate, ntau cov ntaub ntawv tseem tab tom tsom rau kev hloov kho txheej txheej.

7. Hlau lithium

Hlau lithium anode yog qhov ntxov tshaj lithium roj teeb anode kawm. Txawm li cas los xij, vim nws qhov nyuaj, kev tshawb fawb yav dhau los tau qeeb. Nrog rau kev nce qib ntawm thev naus laus zis, kev tshawb fawb ntawm cov hlau lithium anodes kuj tseem txhim kho. Cov hlau lithium anode muaj lub peev xwm theoretical tshwj xeeb ntawm 3860mAhg-1 thiab lub peev xwm ntawm cov hluav taws xob tsis zoo ntawm -3.04V. Nws yog ib qho anode nrog lub zog ceev heev. Txawm li cas los xij, kev ua haujlwm siab ntawm lithium thiab cov txheej txheem tsis sib xws thiab cov txheej txheem desorption thaum lub sij hawm them nyiaj thiab tso tawm ua rau pulverization thiab lithium dendrite kev loj hlob thaum lub voj voog, ua rau muaj kev puas tsuaj sai ntawm cov roj teeb.

Hauv kev teb rau qhov teeb meem ntawm cov hlau lithium, cov kws tshawb fawb tau siv txoj hauv kev los cuam tshuam kev loj hlob ntawm dendrites hauv lithium anode los txhim kho nws txoj kev nyab xeeb thiab lub neej voj voog, suav nrog kev tsim cov khoom siv hluav taws xob hluav taws xob sib txuas (SEI films), lithium anode qauv tsim, Kev hloov kho electrolyte thiab lwm txoj hauv kev.

8. Tin-raws li cov ntaub ntawv

Lub peev xwm theoretical tshwj xeeb ntawm tin-raws li cov ntaub ntawv yog siab heev, thiab theoretical tshwj xeeb muaj peev xwm ntawm cov tin ntshiab tuaj yeem ncav cuag 994mAh / g. Txawm li cas los xij, qhov ntim ntawm cov hlau tin yuav hloov pauv thaum lub sijhawm txheej txheem ntawm intercalation thiab deintercalation lithium, uas ua rau lub ntim nthuav dav ntau dua 300%. Cov khoom deformation tshwm sim los ntawm qhov ntim qhov nthuav dav no yuav ua rau muaj qhov cuam tshuam loj hauv lub roj teeb, ua rau lub roj teeb lub voj voog ua haujlwm tsis zoo thiab lub peev xwm tshwj xeeb kom lwj sai dhau. Cov khoom siv tin-raws li tsis zoo electrode muaj xws li hlau tin, tin-raws li alloys, tin-based oxides, thiab tin-carbon composite cov ntaub ntawv.