Kev siv hluav taws xob siab ceev

soj ntsuam lub zog cia muaj peev xwm, durability thiab nqi cov ntaub ntawv ntawm lub roj teeb. Tam sim no, lub zog siab tshaj plaws lithium roj teeb uas muaj zog tshaj plaws siv cov txheej txheem lithium hloov pauv hlau oxide LiMo2 (M = Ni, Co thiab Mn lossis Al) ua cov ntaub ntawv cathode (≈150? 200mahG-1 muaj peev xwm tawm tau zoo) 1? Graphite (theoretical Lub peev xwm tshwj xeeb yog 372mahG-1) ua cov ntaub ntawv ua haujlwm anode. Ntxiv ib feem ntawm silicon (txog li 15si4, 3579mahgsi? 1) ua pov thawj los ua ib lub tswv yim zoo los ua kom muaj zog ntxiv. Piv txwv li, Yim et al. siv cov ntaub ntawv sib xyaw ntawm graphite thiab silicon hmoov (5% wt%) los npaj thiab kuaj polyvinyl imine nplaum anodes. Tom qab 350 lub voj voog, qhov zoo tshaj plaws electrode muaj peev xwm ntawm 514 mahG-1, uas yog 1.6 npaug ntawm kev lag luam graphite anodes, tus sau tau hais. Txawm li cas los xij, xaus lub voj voog kev nyab xeeb ntawm cov ntsiab lus siab thiab siab load silicon anodes yog qhov nyuaj heev. Qhov tsis xws luag loj tshaj plaws ntawm silicon raws li cov ntaub ntawv kev ua haujlwm anode yog: (I) siab irreversibility, tshwj xeeb tshaj yog nyob rau hauv thawj ob lub voj voog, xws li sab cuam tshuam nrog cov electrolyte; (II) thiab lithium tom qab alloying, lub ntim hloov pauv loj, ua rau cov khoom tawg thiab cov anode self-pulverizes.

Nws yuav tsum raug sau tseg tias tag nrho cov kev cuam tshuam rov qab no yuav tsis tsuas yog ua rau muaj kev cuam tshuam loj ntawm impedance thaum lub sijhawm ua haujlwm roj teeb, tab sis kuj ua rau cov cathode lithium depletion. Tsis tas li ntawd, kev poob ntawm kev sib cuag ntawm silicon hais nyob rau hauv conductive carbon dub / binder network thiab / los yog collector yuav ua rau kom muaj peev xwm degradation. Nyob rau hauv xyoo tas los no, tshiab thiab / lossis txhim kho electrolytes, additives thiab polymer binders tau raug sim los kov yeej cov teeb meem loj ntawm silicon anodes. 11, 13, 15? 17 Tsis tas li ntawd, kev tsom mus rau kev npaj cov ntaub ntawv ua haujlwm zoo ntawm silicon-based redox. Los ntawm qhov kev xav ntawm cov kev tshawb fawb no, tsuas yog qee qhov ntawm lawv tau txiav txim siab ntawm no. Tshwj xeeb, silicon thiab SiOx cov ntaub ntawv thiab lawv cov ntaub ntawv sib xyaw, tshwj xeeb tshaj yog cov pa roj carbon nanoparticles, muaj kev cia siab dav hauv kev siv zog cia yav tom ntej. Piv txwv li, 18-21, Breitung et al. tsim cov khoom sib xyaw ntawm silicon hais thiab carbon nanofibers. Tom qab ntau pua lub voj voog, nws lub peev xwm yog kwv yees li ob zaug ntawm qhov qub silicon particle electrode. Cov txiaj ntsig tau pom tias muaj peev xwm tuav tau cov pa roj carbon-coated silicon hais tau zoo dua tom qab cov piam thaj tau npaj los ntawm txoj kev hydrothermal. Kev tshoov siab los ntawm cov kev tshawb fawb no, lub hom phiaj ntawm txoj kev tshawb no yog siv cov polymer pre-coated silicon particles los npaj nano-si / C composites nrog ib tug core-plhaub qauv. Electron microscopy, X-ray diffraction thiab Raman spectroscopy tau siv los ua cov qauv ntawm cov hmoov carbonized ntawm 700 ~ 900 ℃. Hauv cov txheej txheem siab, qhov sib txawv electrochemical mass spectrometry thiab acoustic emission method tau siv los txheeb xyuas qhov ntim nthuav dav, kev nkag mus rau tus cwj pwm thiab tus cwj pwm deformation / degradation ntawm si / C composite hais ntawm qhov tseeb electrode.