Cov ntsiab lus ntawm qhov tseeb tshawb nrhiav kev kawm tshiab hauv graphite-based lithium battery anode cov ntaub ntawv!

Cov khoom siv graphite raug suav hais tias yog cov khoom siv anode zoo rau cov roj teeb lithium vim tias lawv lub siab ruaj khov, kev coj zoo, thiab cov khoom siv dav. Txawm li cas los xij, qhov muaj peev xwm tshwj xeeb thiab cov kev ua tau zoo ntawm ntuj graphite anode tsis tuaj yeem ua tau raws li qhov xav tau ntawm cov khoom siv anode siab. Txhawm rau daws qhov teeb meem no, cov kws tshawb nrhiav tau ua tiav kev tshawb fawb ntawm kev hloov kho ntawm nws.

Tsab xov xwm no piav qhia txog kev tshawb nrhiav kev vam meej ntawm graphite anode cov ntaub ntawv rau lithium-ion roj teeb los ntawm cov txheej txheem hloov ntawm graphite anodes, thiab taw qhia qhov zoo thiab qhov tsis zoo ntawm ntau hom kev hloov kho. Nws ntseeg tias kev hloov kho synergistic los ntawm ntau txoj kev yog ib txoj hauv kev zoo rau kev nkag siab txhim kho graphite anode cov ntaub ntawv. Cov.

I. Taw Qhia

Cov pa roj carbon anode cov ntaub ntawv uas tau kawm txog tam sim no suav nrog cov roj carbon graphite (ntuj flake graphite, graphiteized mesophase carbon microspheres, thiab lwm yam) thiab cov tsis muaj graphitized carbon (mos carbon, roj carbon tawv, thiab lwm yam). Ntawm lawv, graphite muaj qhov zoo ntawm cov nqi them tsawg thiab tawm hluav taws xob platform, muaj kev ruaj khov lub voj voog thiab tsis tshua muaj nqi, thiab raug txiav txim siab ua qhov zoo tshaj plaws tsis zoo electrode hauv cov khoom siv roj teeb lithium-ion tam sim no. Tam sim no, kev tshawb fawb hloov kho ntawm graphite ntuj tau ua qee qhov kev nce qib thiab tau ua lag luam.

Cov duab hluav taws xob tsis zoo Graphite feem ntau siv cov tshuaj pleev ib ce graphite, tab sis muaj ob peb qhov tsis zoo:

1 Cov flake graphite hmoov muaj qhov tshwj xeeb loj hauv cheeb tsam, uas muaj qhov cuam tshuam ntau dua rau thawj zaug kev them nyiaj thiab kev ua haujlwm tawm ntawm qhov tsis zoo electrode;

2 Lub txheej txheej qauv ntawm graphite txiav txim siab tias Li + tuaj yeem tsuas yog los ntawm sab npoo kawg ntawm cov khoom thiab maj mam mus rau hauv cov lus. Vim lub anisotropy ntawm flake graphite, Li + diffusion kev yog ntev thiab tsis xwm yeem, uas ua rau lub peev xwm tshwj xeeb qis;

3. Qhov sib xyaw ua ke me ntawm cov kab graphite tsub kom qhov sib txawv tsis haum ntawm Li +, thiab tus nqi ua haujlwm tsis zoo. Li + yog qhov yooj yim tso rau ntawm graphite nto los tsim lithium dendrites thaum them sai, uas ua rau muaj kev phom sij txaus ntshai.

Txhawm rau daws qhov teeb meem saum toj no qhov tsis txaus ntawm flake graphite, nws yog qhov yuav tsum tau hloov kho graphite thiab ua kom zoo ntawm kev ua haujlwm ntawm cov khoom tsis zoo electrode. Cov kev hloov kho tam sim no feem ntau suav nrog spheroidization, kho saum npoo thiab doping kev hloov kho.

2. Kev Sib Raug Zoo

Ua rau qhov teeb meem ntawm qhov tsis tshua muaj peev xwm ntawm qhov tsis zoo electrode ntawm lithium ion roj teeb tshwm sim los ntawm anisotropy ntawm flake graphite, morphology ntawm flake graphite yuav tsum tau hloov kho kom nws ua isotropic li sai tau.

Kev tsim khoom ntawm spherical graphite tau muaj kev lag luam. Hauv kev tsim khoom hauv kev lag luam, cua kev hloov kho tshuab tshuab yog siv dav rau spheroidize flake graphite. Ntawm lawv, airflow vortex pulverizer yog cov khoom siv siv tas. Txoj kev no muaj tsawg dua impurities thaum lub sijhawm txheej txheem spheroidization, tab sis nws cov cuab yeej muaj qhov loj me, thiab qhov nyiaj ntawm graphite yog qhov loj, thiab cov txiaj ntsig yog tsawg, uas yog qhov txwv tsawg hauv kev npaj kuaj.

Xyoo tsis ntev los no, qee cov kws tshawb fawb tau siv lub pob feem cuam tshuam me me rau kev npaj mus kuaj. Los ntawm kev txheeb xyuas qhov hloov pauv ntawm porosity thaum lub sijhawm txheej txheem spheroidization, lawv pom tias qhov nce ntawm lub zog thaum lub sijhawm txheej txheem spheroidization nce qhib qhov porosity ntawm graphite hais thiab txo lawv cov porosity. , Uas yuav cuam tshuam nws cov electrochemical kev ua tau zoo. Ntxiv rau qhov tau hais los ntawm kev sib tsoo qhuav saum toj no, qee tus kws tshawb fawb kuj tseem siv agitated sib tsoo ntub txoj kev sib tsoo, siv dej ua qhov nruab nrab, ntxiv cov carboxymethyl cellulose ua rau cov khoom sib kis kom tiv thaiv graphite los ntawm agglomerating hauv dej, txoj kev sib tsoo no tuaj yeem Graphite hais tau zoo. de-angularized; tom qab cov khoom lag luam raug faib los ntawm cov cua daj cua dub thiab cov kev loog, cov khoom loj nrog cov nqaim loj tau txais. Kev tshawb fawb qhia tau tias tom qab spheroidization thiab kev faib tawm, nws lub peev xwm thim rov qab yog qhov nce txog li 20mAh / g.

Ntxiv nrog rau kev teeb tsa cov graphite hais lawv tus kheej, ultrafine graphite hmoov kuj tseem tuaj yeem sib raug zoo rau hauv cov duab kheej kheej los ntawm phau ntawv binder. Cov graphite spheres npaj los ntawm hom no muaj isotropy zoo heev. Xyoo tsis ntev los no, qee tus kws tshawb fawb tau siv cov piam thaj ua ib lub cim ntawm cov pa roj carbon monoxide thiab ua cov ntawv, thiab tshuaj tsuag kom qhuav kom zoo rau nano-silicon hais thiab graphite hais ua ke, thiab agglomerate ultrafine graphite hais ua ntu zus, kom lub peev xwm tshwj xeeb tuaj yeem ncav cuag 600mAh / Tshaj sau g, lub peev xwm ploj ntawm silicon thaum them nyiaj tawm thiab tawm mus yog kov yeej rau qee yam, thiab lub peev xwm tuav tus nqi tom qab 100 mus yog ≥90%.

Wu li al. siv lub viscosity ntawm polyvinyl cawv rau kev sib khi thiab qhuav cov ultrafine graphite hmoov rau isotropic tsis tu ncua kheej kheej qee qhov los ntawm txau kom qhuav. Vim tias qhov khoob me me ntawm cov graphite zoo, lub voj voog kev nyab xeeb tau nce. Tom qab 105 mus ncig Lub peev xwm tshwj xeeb tseem nyob ntawm 367mAh / g, tab sis vim tias muaj cov micropores, qhov pib ua haujlwm tau tsawg dua ntawm 77%; tom qab ntxiv cov roj carbon citrate txheej, kev pib ua kom tau nce mus rau 80%. Txoj kev no tsis muaj qhov xav tau siab ntawm kev coj tus yam ntxwv ntawm cov khoom siv graphite, thiab cov isotropy ntawm cov ntawv tsim tau yog qhov zoo. Nws muaj lub voj voog ruaj khov dua kev ua haujlwm zoo dua li graphite hmoov thiab lub zog muaj peev xwm kom ze rau 372mAh / g.

Los ntawm spheroidizing flake graphite, qhov muaj peev xwm tshwj xeeb (≥350mAh / g), thawj lub voj voog ua haujlwm (≥85%) thiab kev ua haujlwm ntawm qhov tsis zoo ntawm cov khoom siv electrode tsis zoo tuaj yeem hloov kho (qhov muaj peev xwm tuav tau zoo tom qab 500 mus yog ≥80%) Cov. Raws li qhov tsis zoo electrode cov khoom siv rau cov roj ntsha lithium ion, cov particle loj d50 yog qhov tsim nyog tshaj ntawm 16 txog 18 .m. Yog tias qhov me me qhov loj me me, qhov tshwj xeeb hauv thaj chaw yog qhov loj dua, ua rau cov electrode tsis zoo noj ntau ntawm Li + thaum thawj lub voj voog, yog li tsim cov khoom siv dielectric interfacial zaj duab xis (SEI zaj duab xis), ua rau thawj lub txim thiab tawm efficiency qis; yog tias qhov loj me qhov loj me, qhov tshwj xeeb ntawm thaj chaw yog qhov loj me. Me me, thaj chaw tiv tauj nrog cov electrolyte yog me me, uas cuam tshuam rau qhov muaj peev xwm tshwj xeeb ntawm cov tsis zoo electrode.

Peb, kho saum npoo

1 Hloov pore qauv

Qhov txheej txheem pore saum npoo ntawm graphite yog qhov tseem ceeb uas txiav txim siab lub peev xwm ntawm cov roj teeb los ntxig lithium. Lub xub ntiag ntawm cov micropores nyob rau saum npoo ntawm cov khoom siv graphite tuaj yeem ua kom muaj qhov sib txawv ntawm cov channel ntawm Li + thiab txo qhov diffusion tsis kam ntawm Li +, yog li ua kom zoo dua tus nqi kev ua tau zoo ntawm cov khoom siv.

Cheng li al. tso graphite rau hauv lub zog alkali (KOH) aqueous tov rau etching, thiab tom qab ntawd annealed nws ntawm 800 ° C hauv ib qho chaw huab cua nitrogen los tsim nanopores rau saum npoo. Cov nanopores no tuaj yeem siv ua kev nkag ntawm Li +, yog li ntawd Li + tsis tuaj yeem nkag los ntawm qhov kawg ntawm sab kawg nkaus xwb ntawm graphite, tab sis kuj tuaj yeem txuas los ntawm lub hauv paus nto, luv luv txoj kev tsiv teb tsaws. Cov. Tom qab kuaj, them nyiaj thiab tawm ntawm tus nqi ntawm 3C, KOH-etched graphite anode muaj kev tuav cia txog 93%, uas yog siab dua li ntawm qhov graphite qub (85%); ntawm tus nqi ntawm 6C, qhov muaj peev xwm tuav tau nce ntawm 74% tuaj yeem ua tiav.

Shim li al. piv cov peev txheej khaws cia ntawm graphite nyoos, KOH etched-annealed graphite, thiab KOH etched graphite ntawm 80 ° C, thiab ua pov thawj tias qhov muaj peev xwm tuav tus nqi ntawm etched graphite ntawm 80 ° C yog qhov zoo tshaj plaws, thiab uas ntawm etching-annealed graphite yog ob. Yog vim li cas rau qhov no yog tias kub-kub annealing rhuav tshem cov qauv siv lead ua. Los ntawm kev cuam tshuam kev cuam tshuam, tom qab 50 cycles, Li + diffusion tsis kam ntawm cov duab graphite tsuas yog 60% ntawm qhov ntawm cov graphite qub, uas qhia ntxiv txog kev ua kom zoo ntawm nws cov kev ua tau zoo npaum li cas.

Qee cov kws tshawb fawb kuj siv vapor deposition kom loj siab-cov pa roj carbon nanotubes rau ntawm graphite nto hauv situ, yog li thawj zaug them nyiaj thiab tawm kev ua haujlwm ntawm graphite yog> 95%, thiab tus nqi rov qab ceev ceev tom qab 528 cycles yog> 92%.

Nws tuaj yeem pom tias qhov kev txhim kho ntawm pore kev teeb tsa ntawm graphite nto tuaj yeem ua kom ntau qhov sib txawv ntawm cov channel ntawm Li + thiab txo qhov tsis txaus siab ntawm Li +, uas yog cov txhais tau tias muaj txiaj ntsig zoo los txhim kho tus nqi kev ua haujlwm. thiab lub voj voog ruaj khov ntawm graphite.

2 Sab oxidation

Oxidation tuaj yeem tshem tawm qhov tsis sib haum ntawm cov pa roj carbon atom saum npoo ntuj, kom qhov oxidation-txo cov tshuaj tiv thaiv ntawm graphite nto tuaj yeem ua kom zoo ib yam. Tib lub sijhawm, cov pawg ua haujlwm xws li -COO- thiab -OH yog tsim nyob rau saum npoo ntawm oxidized ntuj graphite. Cov pawg ua haujlwm tau khi rau saum npoo ntawm ntuj graphite nyob rau hauv daim ntawv ntawm covalent daim ntawv cog lus, thiab tsim cov txheej txheem tshuaj khov kho SEI nyob rau saum npoo ntawm ntuj graphite thaum them thiab tawm mus, yog li txhim kho thawj nqi them ua haujlwm ntawm ntuj graphite thiab lub hlis txhim kho lub neej ntawm graphite. Cov oxidant feem ntau xaiv O2, HNO3 thiab H2O2.

Cov tshuaj oxidation siv cov roj theem oxidant feem ntau yuav tsum tau kho cov kub kom kho qhov teeb meem saum npoo ntawm graphite hais. Shim li al. siv huab cua ua tus oxidant los oxidize ntuj graphite ntawm 550 ° C. Txoj kev tshawb no pom tias qhov hnyav poob thaum lub sijhawm oxidation txheej txheem muaj feem ntsig txog qhov txo qis hauv thaj chaw tshwj xeeb; tom qab oxidation, nto txoj kab uas hla ntawm ntuj graphite yog 40 ～ 400A. Thaj chaw thaj chaw tau raug txo qis, thiab nws cov kev ua haujlwm hauv lub voj voog thiab thawj qhov ua haujlwm tawm ntawm lub zog ua haujlwm tau zoo dua, tab sis nws lub peev xwm thim rov qab thiab tus nqi kev ua tau zoo tsis hloov.

Ib qho ntxiv, qee qhov cov roj ntsha tsis muaj zog xws li H2O thiab CO2 ntxiv rau cov roj inert rau oxidize graphite ntawm qhov kub. Cov kev sim pom tau hais tias kev qhia ntawm Ni, Co, Fe thiab lwm yam catalysts hauv cov txheej txheem oxidation tuaj yeem txhim kho cov tshuaj tiv thaiv oxidation, thiab Li kuj tuaj yeem tsim cov alloys nrog cov hlau siv los ua oxidation catalysts, thiab cov alloys no kuj tseem tuaj yeem pab ua lub zog thim rov qab.

Kev siv ntawm cov kua muaj zog oxidizing reagents (xws li H2O2, HNO3, thiab lwm yam) tuaj yeem oxidize graphite ntawm qhov kub tsawg dua. Feem ntau, cov nplaim ntawm graphite hais yog micro-oxidized lossis micro-swelled. Wu li al. siv ntau cov oxidants (ammonium persulfate, H2O2, cerium sulfate, thiab lwm yam) txhawm rau oxidize graphite anode cov ntaub ntawv, thiab tau soj ntsuam nano-pores saum nplaim graphite hais los ntawm kev daws teeb meem kis tau hluav taws xob microscopy (HRTEM), uas yog micro-oxide graphite Qhov peev xwm thim rov qab muab tau lub hauv paus.

Mao li al. npaj micro-oxidized graphite nrog K2FeO4 raws li oxidant, uas tshem tawm qhov tsis sib haum ntawm cov graphite nto, thiab qhia nanopores thiab qee cov ntsiab lus los ua kom muaj peev xwm thim rov qab ntawm graphite los ntawm 244mAh / g rau 363mAh / g.

Tsis tas li ntawd, qee tus neeg siv cov oxidizers thiab intercalants rau micro-nthuav dav graphite, uas ua kom dav dav rau cov roj ntsha lithium-intercalation channel thiab txhim kho cov roj ntsha lithium-intercalation muaj peev xwm thiab kev ua haujlwm tau zoo. Zou li al. siv H2O2 oxidant thiab concentrated sulfuric acid ua tus neeg sawv cev sib xyaw ua ke npaj cov micro-nthuav graphite; tom qab ntawd cov phenolic resin tau siv los ua kev sib txuas ua ntej rau cov pa roj carbon txheej, kom lub peev xwm tshwj xeeb ntawm cov khoom tsis zoo electrode tau mus txog 378mAh / g, thiab tom qab 100 mus los ntawm lub txim thiab tawm, qhov peev xwm tuav tau yog 100%.

Nws tuaj yeem pom tau tias tom qab micro-nthuav dav thiab carbon-txheej sib xyaw kev hloov kho kev kho mob, lub voj voog kev ua tau zoo ntawm cov khoom siv sib xyaw tau zoo heev piv nrog ntuj flake graphite thiab coated ntuj flake graphite. Kev kho oxidation ntawm graphite yog qhov tseem ceeb kom tshem tawm cov pa roj carbon tsis sib haum ntawm cov nplaim graphite lossis nce nanopores, nthuav txoj kev ntawm Li + kev tso tawm thiab tso tawm, uas tuaj yeem txhim kho tus nqi kev ua haujlwm thiab lub voj voog ruaj khov ntawm cov khoom tsis zoo electrode. , thiab cov nyhuv ntawm kev txhim kho ntawm qhov muaj peev xwm sib piv tsis yog loj. Txoj haujlwm no yog tib yam Hloov pore qauv ntawm graphite nto yog tib yam.

3 Cov nplaim fluorination nto

Cov fluorinated graphite yog npaj los ntawm fluorinating saum npoo ntawm ntuj graphite. Los ntawm kev kho tshuaj fluorination, CF txheej txheem tsim nyob rau saum npoo ntawm ntuj graphite, uas tuaj yeem ua kom muaj zog ntawm cov txheej txheem ruaj khov ntawm graphite thiab tiv thaiv graphite flakes los ntog tawm thaum lub voj voog. Nyob rau tib lub sijhawm, nplaim fluorination nto ntawm ntuj graphite kuj tseem tuaj yeem txo qhov tsis kam nyob rau hauv Li + cov txheej txheem kev tshaj tawm, ntxiv qhov muaj peev xwm tshwj xeeb, thiab txhim kho nws lub txim thiab tawm haujlwm.

Wu li al. siv roj av argon uas muaj 5% fluorine los fluorinate ntuj graphite ntawm 550 ° C. Tom qab 5 lub voj voog, lub coulombic efficiency nce ntawm 66% mus rau 93%, thiab qhov muaj peev xwm tshwj xeeb kuj tau siab dua qhov theoretical tshwj xeeb muaj peev xwm ntawm graphite. Matsumoto li al. siv ClF3 ua cov txheej txheem graphite ntuj nrog qhov ntau thiab tsawg qhov loj me. Tom qab kho, nws pom tias muaj F thiab Cl ntsiab ntawm sab graphite, thiab qhov me me qhov loj me ntawm cov graphite ntuj muaj qhov chaw me dua. Los ntawm kev them nyiaj thiab tawm mus kuaj, thawj tus nqi them thiab cov khoom tawm ntawm txhua qhov qauv tau nce los ntawm 5% mus rau 26%.

Yin li al. synthesized hauv polythiophene / graphite fluoride cov khoom sib xyaw los ntawm polymerizing thiophene monomers nyob rau sab nrauv ntawm fluorinated graphite ua cov ntaub ntawv raw, thiab pom tias Pth txheej muaj 22.94% tuaj yeem tso tawm ntawm tus nqi siab ntawm 4C, thiab lub zog ceev tuaj yeem ncav cuag 1707Wh / Kg, uas yog siab dua li cov khoom siv graphite zoo.

Los ntawm kev kho fluorination ntawm graphite, qhov ua tau zoo thiab kev voj voog tau txais txiaj ntsig zoo, tab sis lub peev xwm tshwj xeeb tsis zoo heev; tom qab fluorinated graphite raug hloov kho dua, qhov peev xwm tshwj xeeb tuaj yeem hloov kho zoo.

4 Txheej hloov kho

Cov kev hloov kho txheej txheej yog raws cov khoom siv graphite-zoo li" tub ntxhais", thiab txheej txheej ntawm amorphous carbon cov khoom lossis" plhaub" ntawm cov hlau thiab nws cov oxide yog coated rau ntawm nws saum npoo los ua cov nplais ua ke nrog" core-plhaub" qauv. Cov ua ntej ntawm cov khoom siv feem ntau amorphous carbon cov khoom suav nrog cov pa roj carbon monoxide qis-kub pyrolytic cov ntaub ntawv muaj xws li phenolic resin, lub suab, thiab citric acid. Cov ntaub ntawv hlau yog feem ntau yog hlau ntsiab nrog kev coj zoo xws li Ag thiab Cu.

Cov txheej txheej txheej ntawm amorphous carbon cov khoom yog loj dua li ntawm graphite, uas tuaj yeem txhim kho qhov sib txawv ntawm kev ua haujlwm ntawm Li +, uas yog sib npaug los tsim Li + tsis txheej ntawm sab nrauv ntawm graphite, yog li txhim kho lub txim siab tam sim no thiab tawm kev ua haujlwm ntawm graphite cov ntaub ntawv; hlau ntsiab tuaj yeem ua kom zoo dua qub Kev coj ua ntawm cov tsis zoo electrode cov khoom ua rau nws lub txim thiab tawm kev ua haujlwm ntawm qhov kub tsawg. Cov txheej txheem ntawm kev siv lub suab ua lub rooj sib tw ua ntej ntawm amorphous cov pa roj carbon monoxide tau dhau los ua qhov kev paub tab thiab tau hais nyob hauv lub ntsiab lus ntau zaus.

Xyoo tsis ntev los no, Han li al. kawm txog kev cuam tshuam ntawm cov sib txawv ntawm cov sib txawv ntawm cov thee txhaws suab (CTP) (yaj hauv hexane, toluene, thiab tetrahydrofuran) thiab cov ntsiab lus sib txawv (20 ℃, 76 ℃, 145 ℃ thiab 196 ℃) ntawm cov graphite anodes. Cov cawv ntawm lub zog tshuaj. Cov kev kawm tau pom tias kev them nyiaj thiab tawm ntawm 5 ° C thiab txheej nrog hexane insolubles thiab toluene solubles hauv CTP tuaj yeem tswj hwm qhov tshwj xeeb ntawm 263mAh / g ntawm 5C; thiab qhov siab dua CTP softening kis, ntau dua qhov muaj peev xwm tshwj xeeb ntawm cov khoom. Lub peev xwm tshwj xeeb ntawm CTP-cov khoom siv nrog qhov muag muag ntawm 196 ℃ tuaj yeem ncav cuag 278mAh / g, thiab tus nqi hloov pauv kuj tseem qis nrog qhov nce ntawm qhov muag kis.

Wu li al. sib xyaw phenolic resin thiab kheej kheej graphite hauv methanol, cov kuab tshuaj evaporated kom qhuav thiab tom qab ntawd annealed ntawm qhov kub siab nyob rau hauv huab cua tsis zoo; los ntawm kev sib tsoo thiab sieving, qhov saum npoo ntawm graphite hais tau tau smoother, uas ua rau nws lub voj voog ruaj khov, thiab tom qab 5 voj voog Nws muaj peev xwm tshwj xeeb yog 172mAh / g siab dua li ntawm cov khoom siv graphite. Ntxiv nrog rau cov nqaj hlau thiab cov phenolic cob, qee cov kws tshawb fawb kuj tau tshawb fawb txog citric acid ua cov amorphous carbon ua ntej hauv xyoo tas los.

Qhov sib xyaw ntawm graphite, hlau thiab hlau oxide tsuas yog ua tiav los ntawm kev nqes rau ntawm nplaim graphite. Cov xim hlau tsis tsuas tuaj yeem txhim kho cov khoom siv hluav taws xob ua kom zoo ntawm graphite, tab sis kuj tseem Sn thiab nws cov oxides thiab alloys tuaj yeem siv los ua cov khoom siv matrix rau lithium cia, uas muaj cov nyhuv synergistic nrog graphite ntxiv rau qhov ua kom zoo ntawm kev ua tau zoo ntawm electrode tsis zoo. Siv NaH los txo SnCl2 lossis SnCl4 hauv n-butanol kom tso nyiaj txheej ntawm nano-Sn nyob rau sab npoo ntawm graphite, qhov ruaj khov muaj peev xwm ntawm 400-500mAh / g tuaj yeem tau txais. Qhov kev tso tawm ntawm cov hlau xws li Ag thiab Cu feem ntau siv cov tshuab hluav taws xob, thiab cov hlau uas tau txais txheej txheej yog du thiab yam. Ntxiv rau, cov nyiaj tsom iav nyiaj kuj yog qhov yooj yim thiab siv tau tus qauv los ua cov txheej xim.

Cov pa roj carbon txheej yog ib txoj hauv kev zoo rau kev ua kom zoo ntawm kev siv lub tshuab hluav taws xob ntawm graphite anodes, tab sis nws cov nyhuv ua kom zoo dua yog txwv. Nws tsuas yog muaj qhov ua kom zoo ib feem ntawm kev ua haujlwm ntawm lub voj voog qhov ruaj khov thiab thawj them nyiaj thiab tawm kev ua haujlwm; hlau txheej tsuas yog txhim kho qhov zoo ntawm kev ua haujlwm thiab kev voj voog ruaj khov ntawm cov khoom siv anode Nws muaj qhov ua kom zoo dua ntawm kev them nyiaj thiab tawm haujlwm ntawm qhov kub tsawg. Yog li no, ob txoj hauv kev ntawm txheej carbon thiab hlau txheej tsis tuaj yeem daws qhov teeb meem ntawm qhov tsis xws li ntawm kev muaj peev xwm ntawm graphite.

Plaub, doping kev hloov kho

Txoj kev hloov kho doping yog qhov hloov tau ntau dua, thiab cov doping hais tau ntau yam. Tam sim no, cov kws tshawb fawb tau mob siab rau hom no. Doping ntawm cov-carbon ntsiab lus rau hauv graphite tuaj yeem hloov kho hluav taws xob lub xeev ntawm graphite, ua kom yooj yim kom tau txais cov khoom siv hluav taws xob, yog li ua kom ntau ntxiv ntawm Li + embedded.

Los ntawm pyrolyzing H3PO4 thiab H3BO3, Park li al. ntse doped P thiab B mus rau saum npoo graphite thiab tsim kev sib txuas tshuaj lom neeg nrog lawv, uas ua zoo txhim kho lub voj voog ruaj khov thiab tus nqi ua haujlwm ntawm graphite. Vim tias Si thiab Sn muaj peev xwm khaws cov roj ntsha lithium, ntau cov kev tshawb fawb tau ua tiav ntawm qhov sib xyaw ntawm ob yam no nrog graphite. Chaw nres tsheb li al. ntxiv cov tshuaj tiv thaiv muaj oxide yajthem oxide rau cov khoom siv graphite anode. Antimony-tin tin oxide particles thiab graphite particles tau sib txuas ua ke los ntawm citric acid kom nce lub peev xwm tshwj xeeb ntawm cov khoom siv anode rau 530mAh / g, thiab lub peev xwm tshwj xeeb tuaj yeem tswj tau tom qab 50 mus. 100%.

Chen li al. ua ke ntawm nano-silicon hais, suab thiab ya raws graphite los ntawm cov tshuaj tsuag kom qhuav kom tau txais qhov tshwj xeeb ntawm 1141 mAh / g. Nyob rau tib lub sijhawm, lwm tus kws tshawb fawb tau sib xyaw graphite, amorphous carbon cov khoom siv ua ntej thiab nano-Si hauv kev txhim kho organic los ntawm ultrasonic, nplawm lossis pob zeb, thiab tom qab ntawd ua kom qhuav thiab annealed cov khoom sib xyaw, uas ua rau muaj peev xwm nce qhov tshwj xeeb muaj peev xwm ntawm qhov tsis zoo electrode. khoom siv. Nws lees tias cov nyhuv synergistic ntawm Si thiab graphite.

Doping cov ntsiab lus sib txawv hauv cov ntaub ntawv graphite muaj qhov sib txawv ntawm kev ua haujlwm zoo rau nws txoj kev ua haujlwm electrochemical. Ntawm lawv, qhov sib ntxiv ntawm cov khoom (Si, Sn) uas tseem muaj lub peev xwm khaws cov roj ntsha lithium muaj qhov cuam tshuam tseem ceeb rau qhov nce ntawm qhov muaj peev xwm tshwj xeeb ntawm graphite anode cov ntaub ntawv, tab sis vim muaj qhov txwv ntawm qhov tshwj xeeb muaj peev xwm ntawm graphite nws tus kheej, zoo tagnrho cov tseem tsis tau tiav.

Tsib, xaus lus hais

Spheroidization, pore tus qauv hloov pauv, oxidation kev hloov kho, hloov tshuaj fluorination thiab txheej txheem hloov kho tuaj yeem txhim kho thawj zaug them nqi thiab kev ua haujlwm tau zoo ntawm graphite-based anode cov ntaub ntawv, nce tus nqi sib txawv ntawm Li + hauv cov khoom siv anode, thiab ua kom zoo dua rau tus nqi kev ua haujlwm. ntawm cov ntaub ntawv anode. Cov nyhuv yog qhov tseem ceeb ntawm kev ua haujlwm ntawm lub voj voog ruaj khov, tab sis tsis muaj ib qho pom tseeb kev ua haujlwm tau txais txiaj ntsig hauv kev txhim kho tshwj xeeb. Doping kev hloov kho tuaj yeem ua tiav cov khoom siv nrog cov roj ntsha sib txawv ntawm lithium, ua kom lawv cov txiaj ntsig zoo, thiab nce qhov tshwj xeeb muaj peev xwm ntawm cov khoom tsis zoo electrode, tab sis nws cov kev ua tau zoo thiab kev voj voog ruaj khov yuav raug txo kom tsawg. Yog li, siv ntau txoj hauv kev los hloov kho qhov sib xyaw ua ke ntawm graphite thiab Si lossis Sn cov ntsiab lus thiab daws qhov tsis xws ntawm lub voj voog tsis zoo ntawm cov ntaub ntawv sib xyaw ua ke yuav dhau los ua qhov tseem ceeb ntawm kev tshawb fawb yav tom ntej.