Kev tsim ntawm yav tom ntejlithium{0}} ion roj teebyuav tsum muaj peev xwm ua tau raws li qhov xav tau ntawm siab -zog- siv cov khoom siv, xws li cov tsheb hluav taws xob ntshiab, ntsaws- hauv tsheb hluav taws xob hybrid, thiab lub zog ruaj khov. Rau cov ntaub ntawv tshiab anode nyob rau hauv txoj kev loj hlob, muaj peev xwm yog ib qho ntawm cov kev qhia tseem ceeb. Raws li cov txheej txheem sib txawv, qee cov neeg sib tw cov ntaub ntawv uas muaj peev xwm theoretical muaj xws li silicon (Si), germanium (Ge), silicon monoxide (SiO), tin (Sn), thiab nws cov oxide (SnOz), uas muaj peev xwm ntawm 783 mA·g (rau SnOz) txog 4211 mA·h / Sih. Txawm hais tias cov ntaub ntawv alloy no muaj peev xwm ua tau zoo dua qub piv rau cov graphite ib txwm muaj (372 mA·bg) thiab lithium titanate (LTO, 175 mA·Ng), qhov ntim hloov pauv thiab qhov pib tsis muaj peev xwm poob lawv tau txais thaum lub sij hawm them nqi thiab tso tawm txwv lawv lub neej. Txhawm rau kov yeej cov teeb meem no, cov kws tshawb fawb tau tshawb nrhiav ntau lub tswv yim, xws li txo qhov loj me me rau nanoscale thiab sim tsim cov khoom siv sib xyaw uas muaj cov khoom siv hluav taws xob lossis tsis muaj zog lithium. Ntawm cov txheej txheem no, kev sib txuas cov khoom siv lithium kub nrog cov ntaub ntawv alloy los tsim cov khoom siv hluav taws xob tsis zoo tau pom tias muaj peev xwm txhim kho kev ua haujlwm ntawm lub voj voog. Tsis tas li ntawd, kev siv cov morphologies sib txawv ntawm nanostructures, xws li nanowires lossis nanotubes, kuj tau ua pov thawj tias yog ib txoj hauv kev zoo rau kev ua tiav cov khoom siv zoo tagnrho anode uas sib xyaw ua haujlwm siab, kev ua haujlwm zoo, thiab lub neej ntev.
Si--Silicon-raws li cov khoom siv anode
Silicon-raws li cov ntaub ntawv anode yog tsim los ntawm cov ntshiab silicon, silicon oxide, thiab silicon/carbon composites. Vim lawv lub peev xwm theoretical siab, kev phooj ywg ib puag ncig, thiab ntau cov kev cia siab ntawm ntuj, lawv tau pom tias yog qhov kev xaiv zoo tshaj plaws rau yav tom ntej - tiam siab - zog- ntom ntom lithium - ion roj teeb anodes. Cov kws tshawb fawb Suav yog thawj zaug hauv ntiaj teb los tawm tswv yim ntawm kev siv nanoscale silicon rau lithium- ion roj teeb. Muab Tuam Tshoj cov khoom siv silicon ntau thiab lub ntiaj teb- ua lub peev xwm tsim tawm ntawm cov khoom siv silicon, nce kev tshawb fawb thiab kev tsim kho ntawm silicon-raws li cov ntaub ntawv anode thiab lawv daim ntawv thov hauv lithium{11}} ion roj teeb yog qhov tseem ceeb heev rau kev paub txog cov thev naus laus zis tseem ceeb ntawm yav tom ntej siab -{12}.
Piv nrog rau cov khoom siv graphite anode ib txwm muaj, silicon nthuav tawm ntau dua theoretical tshwj xeeb muaj peev xwm (4211 mA·h / g) thiab qhov muaj peev xwm qis dua (0.5V). Qhov tseem ceeb, silicon lub zog ua haujlwm yog me ntsis siab dua li ntawm graphite. Daim duab 5-9 qhia txog qhov tshwj xeeb atomic kev npaj hauv silicon siv lead ua. Thaum lub sij hawm them nyiaj, siv silicon raws li cov anode tuaj yeem txo qhov chaw lithium plating, yog li txhim kho roj teeb kev nyab xeeb. Tsis tas li ntawd, silicon muaj ntau thiab pheej yig. Txawm li cas los xij, kev siv silicon rau lithium{11}}ion roj teeb anodes kuj muaj qee qhov kev nyuaj. Raws li cov khoom siv semiconductor, silicon muaj cov conductivity tsis zoo. Tom qab ntau qhov kev them nqi- tawm mus, qhov hloov pauv loj tshwm sim los ntawm lithium{14}}ion ntxig thiab tso tawm tuaj yeem ua rau cov khoom tawg, cuam tshuam rau cov qauv kev ruaj ntseg thiab ua rau muaj kev sib cais ntawm cov khoom siv los ntawm cov khoom siv tam sim no, cuam tshuam rau lub roj teeb lub voj voog lub neej. Tsis tas li ntawd, qhov kev nthuav dav no tseem cuam tshuam rau kev tsim cov khoom ruaj khov thiab siv tau zoo-state electrolyte interface (SED) zaj duab xis ntawm silicon nto. Uniformly dispersing ntshiab silicon los yog nws cov tebchaw nyob rau hauv ib tug carbon matrix yuav alleviate cov teeb meem no rau ib txhia qhov chaw: ntawm ib sab, nws txhim kho tag nrho cov hluav taws xob conductivity ntawm composite khoom; ntawm qhov tod tes, muaj cov pa roj carbon monoxide pab txo qhov kev ntxhov siab los ntawm silicon ntim hloov, txo kev puas tsuaj rau cov qauv electrode; ib txhij, carbon tuaj yeem txhawb kev ruaj khov ntawm SEI zaj duab xis. Yog li ntawd, cov khoom siv sib xyaw ua ke sib xyaw ua ke zoo ntawm silicon thiab carbon yog suav tias yog ib qho ntawm cov neeg sib tw zoo tshaj plaws rau kev sib tw tom ntej - tiam siab - zog- roj teeb lithium-ion ceev.
SiO
Dhau li ntawm silicon, silicon monoxide (SiO) kuj tseem suav tias yog cov khoom siv anode rau lithium{0}} ion roj teeb vim nws muaj peev xwm theoretical tshaj 1600 mA·h / g. Tsis tas li ntawd, lithium- kev sib koom ua ke ntawm cov pa oxygen cuam tshuam qhov kev hloov pauv me me thiab txo qis kev ua kom lub zog thaum lub sijhawm them thiab tawm. Cov tshuaj muaj peev xwm electrochemical thaum lub sijhawm txheej txheem no suav nrog kev hloov pauv ntawm SiO rau Si thiab LiO, tom qab ntawd los ntawm kev tsim cov silicon-lithium alloy nrog Li; los yog kev tsim ncaj qha ntawm silicon-lithium alloy thiab LixSiO2. Nws yog ib qho tseem ceeb uas cov khoom ntshiab SiO yog thermodynamically tsis ruaj khov ntawm txhua qhov kub thiab muaj peev xwm decompose rau Si thiab SiO2 nyob rau hauv tej yam kev mob los ntawm ib tug disproportionation cov tshuaj tiv thaiv. Zoo ib yam li silicon, SiO tau txais cov ntim loj loj lossis kev cog lus thaum lub sij hawm lithium tso thiab rho tawm. Tsis tas li ntawd, SiO muaj cov conductivity tsis zoo, ua rau qeeb lithium{11}}ion ingress thiab egress tus nqi. Txhawm rau daws cov teeb meem no, txhim kho lub peev xwm thim rov qab, thiab txhim kho lub voj voog ruaj khov, cov kws tshawb fawb tau tshawb nrhiav ntau yam tswv yim. Ntawm cov no, cov txheej txheem carbon txheej, electrochemical txo ntawm lithium hauv SiO, thiab txo SiO particle loj yog suav tias yog qhov tshwj xeeb tshaj yog txoj hauv kev. Tshwj xeeb, thaum ua ke nrog cov khoom me me thiab cov pa roj carbon coatings, txoj kev diffusion ntawm lithium ions tuaj yeem ua kom luv luv, thaum txhim kho electron thiab ion conduction efficiency, yog li kov yeej cov teeb meem uas tau hais tseg.
GE
Germanium tau txais kev saib xyuas tseem ceeb hauv lithium-ion roj teeb anode cov ntaub ntawv tshawb fawb vim nws lub peev xwm lithium siab (1623 mA·h / g) ntawm Liz2Ge5 stoichiometric piv thiab nws cov txheej txheem thim rov qab lithium thiab cov txheej txheem rho tawm. Txawm hais tias germanium kim dua silicon thiab muaj peev xwm qis dua me ntsis, nws muaj cov txiaj ntsig tseem ceeb, xws li conductivity 10,000 npaug ntawm silicon thiab qhov sib txawv ntawm tsuas yog 0.67 eV. Cov kev tshawb fawb tau pom tias qhov diffusion tus nqi ntawm lithium ions hauv germanium yog 15 npaug sai dua li hauv silicon ntawm 360℃thiab 400 npaug sai dua ntawm chav tsev kub. Cov khoom no muab germanium zoo heev - kev ua haujlwm tawm tam sim no thiab cov nqi thauj khoom ntau dua. Qhov kev ua tau zoo no - fais fab tuag yog qhov tseem ceeb tshwj xeeb rau cov ntawv thov uas xav tau siab - kev ua tau zoo zog, xws li tsheb fais fab. Txawm li cas los xij, zoo ib yam li silicon, germanium kuj ntsib qhov teeb meem ntawm qhov ntim nthuav dav txog li 300%, uas tau dhau los ua teeb meem rau nws txoj kev siv tau hauv lithium - ion roj teeb. Los ntawm kev siv nanostructure tsim xws li nanoparticles, nanowires, lossis nanotubes, qhov cuam tshuam tsis zoo ntawm kev hloov pauv tuaj yeem txo tau zoo, yog li txhim kho coulombic efficiency. Nws yog ib qho tsim nyog sau cia tias kev npaj ntawm germanium nanoparticles -conductive substrate composites siv txoj kev yooj yim xws li cov khoom -state pyrolysis tuaj yeem ua kom zoo dua cov electrochemical kev ua tau zoo ntawm cov electrodes.
SnO2
Tin dioxide (SnO2), thawj zaug tsim los ntawm Fujifilm, tau txais kev saib xyuas thoob plaws raws li cov khoom siv tsis zoo rau lithium- ion roj teeb vim nws lub peev xwm theoretical siab thiab qis ua haujlwm voltage (kwv yees li 0.6 eV, txheeb ze LiLi). Hauv cov txheej txheem tshuaj tiv thaiv electrochemical, nws thawj zaug dhau los ua ib feem ntawm qhov tsis tuaj yeem hloov pauv, qhov twg SnO2 raug txo rau cov hlau tin (Sn) thiab lithium oxide (LiO); Tom qab ntawd, ib theem thim rov qab tshwm sim, suav nrog kev tsim thiab decomposition ntawm tin -lithium alloy. Raws li kev xav, txhua lub mole ntawm SnO2 tuaj yeem hnov mob nrog 8.4 mol ntawm lithium, sib xws rau qhov muaj peev xwm theoretical ntawm 1491 mA·h / g. Txawm li cas los xij, muab qhov rov qab qis dua ntawm qhov kev txo qis thawj zaug, hauv kev siv cov tswv yim, tsuas yog lub peev xwm ua tau zoo los ntawm cov txheej txheem alloying / dealloying tom ntej -kwv yees li 783 mA·h / g- feem ntau suav hais tias, thiab tus nqi no yog siv los ua lub peev xwm theoretical ntawm SnO2 khoom. Tsis tas li ntawd, thaum lub sij hawm them nqi- lub voj voog tawm, cov khoom no tau txais kev nthuav dav loj (tshaj 200%), ua rau poob peev xwm loj. Txog rau qhov kawg no, cov kws tshawb fawb tau mob siab rau kev txhim kho kev caij tsheb kauj vab ntawm SnO2 thiab txo qis kev muaj peev xwm rov qab los ntawm kev hloov pauv los ntawm ntau txoj hauv kev.