
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Ababhobi: 
 
 
 
 
 
 
 
 
 
 
 In Hyuk Son Jong Hwan Park Seongyong Park Kwangjin Park Sangil Han Jaeho Shin Seok-Gwang Doo Yunil Hwang Hyuk Chang Jang Wook Choi Isishwankathelo Ukuphuculwa kwempahla enye ngaphandle kokudela ezinye kunzima kwiibhetri ze-lithium-ion ngenxa yendlela yokurhweba phakathi kweeparameter eziphambili. Apha singcamla inkqubo yokufudumala komphunga ukuvelisa indibaniselwano ye-graphene–silica, ebizwa ngokuba yi-graphene ball. Isakhiwo sayo esihleliyo semilinganiselo emithathu enemichibi ye-silicon oxide nanoparticles ivumela i-1% ye-graphene ball ukuba igqunywe ngokulinganayo kwikhatod i-nickel-rich layered ngokusebenzisa iNobilta milling. Ukugquma kwe-graphene-ball kuphucula ubomi besangqa kunye nokukwazi ukutshaja ngokukhawuleza ngokucinezela iingongoma ezibi kunye nokubonelela ngeendlela zokuqhuba. I-graphene ball ngokwayo ikwaqhuba njengezinto ze-anode ezinekhono eliphakamileyo le-716.2 mAh g−1. Isangqa esigcweleyo esine-graphene balls sandisa ubuninzi bamandla e-27.6% xa kuthelekiswa nesangqa solawulo ngaphandle kwe-graphene balls, sibonisa ithuba lokufumana i-800 Wh L−1 kwisetingi yesangqa esentengiso, kunye nokugcinwa kwamandla okuchanekileyo kwe-78.6% emva kwesangqa esi-500 kwi-5C kunye no-60 °C. Intshayelelo Ukuqhubeka kophuhliso lweebhetri ze-lithium-ion (LIBs) kuye kwazisa ukuphucuka okumangalisayo kwiinkalo ezahlukeneyo zokusebenza kwazo, kubandakanywa ubuninzi bamandla, ubuninzi bamandla, ubomi besangqa, kunye nokhuseleko. Ngoku, izixhobo ze-IT eziphathwayo zibonelela ngesiqingatha esikhulu sezicelo ze-LIB, apho iinkcukacha zokusebenza ze-LIBs zangoku zidla ngokwanelisa , , . Nangona kunjalo, njengoko izithuthi zombane (EVs) zifikelele kwiimarike ze-LIB, iimpawu eziphambili zombane zibeke imigangatho enzima ngakumbi; ngelixa ubuninzi bamandla aphezulu bufuna ukwandiswa komgama wokuhamba, iikinetiki zokuphendula ezibuyiselweyo zifunwa ukutshaja ngokukhawuleza kunye nokusebenza okuphezulu. Ukhuseleko ngokuqinisekileyo yinto ebalulekileyo kwizicelo ze-EV. Ingxaki enkulu ikukoyisa ubudlelwane bokuthathelana phakathi kwezi mpawu ziphambili; kudla akunakwenzeka ukuphucula impahla enye ngaphandle kokudela ezinye. 1 2 3 Ububudlelwane bokuthathelana bubonakala ngakumbi phakathi kobuninzi bamandla kunye nokutshaja ngokukhawuleza (okanye ubuninzi bamandla). Ngelixa ukusetyenziswa kwezinto ezincinci njengezinto ezisebenzayo ,  kunye nokudibanisa izinto ezincinci ze-carbon , ,  njengezixhobo zokudibanisa zibonise ukwanda kwezinga lokutshaja ngokunciphisa ibanga lokudibanisa kunye nokuchasana kwangaphakathi, uninzi lwezi zinto azikafikeleli kumgangatho wokwenza kwiteknoloji ye-LIB yangoku. Iimilo zokucofa kwezinto ezincinci ziphantsi kakhulu kunezo zomlinganiselo omkhulu, nto leyo eyonakalisayo kubuninzi bamandla, into ebalulekileyo kwizicelo ezininzi ze-LIB kunomlinganiselo wayo. Ngokufanayo, ukunciphisa ukuchasana kwangaphakathi, ukudibanisa izinto ezincinci ze-carbon ezifana ne-graphene kuye kwaba luncedo ekwandiseni ukhuseleko lombane lwee-electrode zesekeli. Nangona kunjalo, ukufezekisa ukusasazwa okulinganayo kokuqulunqwa okuncinci kobunzima (oko kukuthi, <3 wt%) izinto ezincinci ze-carbon kwinkqubo enkulu yeslurry ayikaboniswa. Ukulungiswa kwezinto ezisebenzayo ezikhoyo ngokudibanisa izinto ezingaphandle ,  okanye ulawulo lwe-stoichiometric , ,  >ngokunjalo kunokwandisa ukudibanisa kweLi ions kwaye ngenxa yoko izinga lokutshaja kwezinto ezisebenzayo zemveli ezineemilinganiselo emikhulu. Uninzi lwezi zinto, nangona kunjalo, lusebenza ngokudela ikhono elithile. 4 5 6 7 8 9 10 11 12 13 Ngaphezu koko, ngaphandle kobuninzi bamandla kunye nokutshaja ngokukhawuleza, ukufumana ubomi obude besangqa, ngakumbi kubushushu obuphezulu (oko kukuthi, 60 °C), kusengumngeni kwi-LIBs eziphambili ezidibanisa izinto zekhatod ezinekhono eliphezulu. Ngelixa izinto ezinje nge-nickel (Ni)-rich kunye ne-Li-rich layered oxide zithathwa njengezinto zekhatod ezizayo ngenxa yeekhono zazo ezikhethekileyo xa kuthelekiswa nezo zemveli ze-LiCoO2, kuyaziwa ukuba ukudibanisa kwe-cation okungaphephekiyo ngexesha lokutshaja kuconsa isakhiwo esilungisiweyo sibe yimidlalo okanye iifom zombutho wokuhlala, kunye neengongoma ezingafunekiyo kumacala ezinto ezisebenzayo. Ukujonga imizamo eyenziwe ukuza kuthi ga ngoku, enye yezona zisisombululo zizizo zokufumana ukutshaja ngokukhawuleza kwezinto zekhatod ezinekhono elincinci lobuninzi bamandla kunye nobomi besangqa ibandakanya ukufumana izinto zokukhusela ezizizo ezingaqinisekisi ukuba ziya kugqunywa ngokulinganayo kwizinto ezisebenzayo ngomlinganiselo omncinci. Apha singcamla i-graphene–silica (SiO x) assembly, ebizwa ngokuba yi-graphene ball (GB), njengezinto zokugquma ezikhatod ezimininzi ezinekhono eliphezulu kunye nezinto ze-anode ze-LIB. I-GB nganye iqulethe i-SiO x nanoparticle centre kunye ne-graphene layers ezijikelezileyo, zidibanisa isakhiwo semilinganiselo emithathu (3D) esinjenge-popcorn. Ii-SiO x nanoparticles zidlala indima ebalulekileyo kwiinkalo ezininzi, njengokuphepha ukwenziwa komaleko we-silicon carbide (SiC) kwi-SiO x –graphene interface ngexesha lokukhula kwe-graphene, ukuqinisekisa ukugquma okulinganayo kwe-GB kwisiphawo sekhathod, kunye nokubonelela ngekhono eliphakamileyo xa i-GB isetyenziswa njengezinto ze-anode. Ukugquma okulinganayo kwe-GB kwikhatod ye-Ni-rich kuphucula ukhuseleko lwesigaba kunye nokudibanisa kombane phezu kwe-electrode, kuphucula kakhulu ukujikeleza kunye nokukwazi ukutshaja ngokukhawuleza kwekhathod. Ukuthatha izibonelelo ezizizo ze-GB, isangqa esigcweleyo esinekhathod egqunywe nge-GB kunye ne-anode ye-GB ibonisa ithuba lobuninzi bamandla obuphezulu obungama-800 Wh L−1 kwimeko yesangqa esentengiso, kunye nokugcinwa kwamandla okujikeleza okungama-78.6% emva kwe-500 cycles kwi-5C kunye no-60 °C. Iziphumo Ukwenziwa kwe-graphene ball Ukufumana i-GB enjenge-popcorn, sakha inkqubo ye-chemical vapor deposition (CVD) yokukhula kwe-graphene. Igsi ye-CH4 yayingena efudumalayo kwindawo yokugquma ubushushu kwindawo ye-SiO2 nanoparticles enobubanzi obungama-20–30 nm kwi-1000 °C. Kubushushu obufanayo, i-CH4 iyakwahlulwa ukuvelisa ii-atom zeselulwelo, ezingakwazi ukunciphisa i-SiO2 ibe yi-SiO x (x < 2). I-OH− ikwaveliswa ngaxeshanye ngokwenkqubo elandelayo: Into ephambili kule nkqubo kukuphuma kwe-SiO x okubonelela ngeendawo zokukhula kwe-graphene, kwaye i-OH− isebenza njenge-oxidant ethambileyo ukuququzelela ukwenziwa kwe-carbon ye-graphitic ukuya kwi-graphene , . Indima ye-oxidants ethambileyo ekwenzeni i-carbon ye-graphitic kuye kwacetyiswa kutshanje  >ngendlela yokuba, ngaphandle kwe-oxidant ethambileyo, ukwenziwa kwe-carbon ye-amorphous kungaphezu kokubaluleka. Ngokwenyani, ukukhula okulula kwe-graphene kusetyenziswa izixhobo zetsimbi kuyaziwa ukuba kwenzeka ngendlela efanayo , , , apho i-oksijini eseleyo phezu komhlaba wetsimbi ibangela inkqubo eyongezelelweyo ukuya ekwenzeni i-carbon ye-graphitic. Ubukho be-oxidant ethambileyo bukhusela ukwenziwa komaleko we-silicon carbide (SiC) phezu komhlaba we-SiO x kuba i-oxidant ikhusela ukuncitshiswa kwe-Si ekwenzeni i-SiC . 14 15 16 17 18 19 19 Kwi-scheme yethu yenkqubo esekelwe kusetyenziso kuphela lwe-CH4, kubushushu obungaphantsi kwe-900 °C, i-graphene kunqabile ukuba ikhule. Ngokungafaniyo, kwi-1050 °C nangaphezulu, ukukhula kwe-graphene kuye kwaba kakhulu kakhulu ekwenzeni i-graphite (Supplementary Fig.  ). Kubalulekile, ubushushu bokukhula be-1000 °C bungaphantsi kunezo (1100–1400 °C) ziqhele ukusetyenziswa kwi-graphene ye-CVD esekelwe kwi-Si kunye ne-SiO2 substrates ngaphandle kwezixhobo zetsimbi , , . Indima ebalulekileyo yendawo yokukhula yachazwa ngesiphumo sokulawula (Supplementary Fig.  ); ukulandela iinkqubo zemveli ze-CVD ezisebenzisa izixhobo zetsimbi, i-CH4 kunye ne-H2 zazingeniswa ngobude bokuhamba komlinganiselo we-3:7 kwi-1000 °C. Ngoba ukwahlulwa kwe-CH4 kuye kwathintelwa yimveliso enkulu ye-H2, ukukhula kwe-graphene kwakucotha kakhulu, kubonisa ukubaluleka kokusetyenziswa kwe-CH4 kuphela ekukhuleni okusebenzayo kwe-graphene kwisicwangciso sethu sokwenziwa. Ngokubanzi, ukukhetha kwezinto ezisetyenziswayo kunye nobushushu benkqubo kwisicwangciso senkqubo yangoku siyahluka kwiinkqubo zangaphambili ze-CVD ezisebenzisa izixhobo zetsimbi kwaye zidlala indima ebalulekileyo ekwenzeni indibaniselwano ye-graphene–SiO x enesakhiwo esihleliyo. 1 20 21 22 2 Ukususela kwinkqubo ye-CVD, iingqungquthela ze-scanning electron microscope (SEM) (Supplementary Fig.  ) kunye ne-transmission electron microscope (TEM) analyses (Fig.  ) zibonisa utshintsho kwisithuthi sokukhula kwe-graphene kunye nemorphology. Emva kwemizuzu emi-5 yenkqubo ye-CVD, ifilimu ye-graphene enobubanzi obu-2–3 iyalungiswa ngokungacacanga phezu komhlaba we-SiO2 (Fig.  , e), kunye nombala womgubo uphendukela emnyama (Supplementary Fig.  ). Ukukhula kwe-graphene kuye kwaba kubonakala kakhulu emva kwemizuzu engama-30 yenkqubo ye-CVD, apho imorphology ye-sheet ye-3D ibonakala kakhulu (Fig.  , f). Umfanekiso we-TEM ophakanyisiweyo (Fig.  ) ubamba iintlobo ezingqukuva kwisithambiso se-graphene, esibonisa umhlaba wayo omkhulu. Emva kwemizuzu engama-30, kwakukwa kwabonwa ukuba ububanzi bee-SiO2 nanoparticles bancipha ukusuka kuma-28.2 ukuya kuma-15.3 nm ngokomndilili (Supplementary Fig.  ). Oku kwenzeka ngenxa yokuba ukukhula kwe-graphene kubandakanya ukuncitshiswa kwe-SiO2 okuthethiweyo kunye nokwenziwa kwe-OH−. Ngenxa yoko, ukukhula okupheleleyo kwe-graphene kufana nokudumba kwe-popcorn kwisakhiwo esikhulu semilinganiselo emithathu, esiveliswe ngokudela iintanga zangoku (Fig.  ). 3a–f 1a–g 1b 3g 1c 1g 4 1h   Ukukhula kwe-Graphene ukusuka kuma-SiO2 nanoparticles.  –  Ukuphathwa kwe-TEM   >ngaphambi kokukhula kwe-CVD,   >emva kwemizuzu emi-5 yokukhula, kunye   >emva kwemizuzu engama-30 yokukhula (iibha zesikali, 50 nm).  –  >Imifanekiso yabo ephakanyisiweyo ngokulandelelanayo (iibha zesikali, 10 nm).   >Umfanekiso ophezulu we-graphene emva kwemizuzu engama-30 yokukhula kunye nembono yayo engozinga ngobukhulu ukusuka ebhotileni elimhlophe (inset) (ibar yesikali, 2 nm).   >Umfanekiso ogqamileyo wokukhula kwe-graphene enjenge-popcorn ukusuka kuma-SiO2 nanoparticles a c a b c d f g h Ukhula lwe-graphene lwacetyiswa ngokuqhubekayo yintlalontle yeengqungquthela ezongezelelweyo. Iingxelo ze-X-ray diffraction (XRD) ezifunyenwe ngexesha lokukhula zibonisa ukuba njengoko inkqubo ye-CVD iqhubeka, iincopho kwi-2θ = 26.44° kunye no-44°, ezihambelana nemigangatho (002) kunye (101) ye-graphite, zikhula ngokuqhubekayo (Fig.  ), zixhasa kwakhona ukwenziwa kwe-carbon ye-graphitic , , . Ukukhula kwe-graphene kwakuboniswa kwiincopho kwi-284.5 kunye no-291.5 eV kwicandelo le-C 1s le-X-ray photoelectron spectroscopy (XPS) analysis (Fig.  ) , . Incopho kwi-284.5 eV inikezelwa kwi-C–C kunye ne-C = C bonds, ezavela kakhulu emva kwemizuzu engama-30 yokukhula ngenxa yokwenziwa kwe-carbon ye-graphitic. Iingxelo ze-XPS ezivelelayo kwicandelo le-Si 1s le-XPS analysis (Fig.  ) ziqinisekisa kwakhona  >ukuncitshiswa kwe-SiO2 ngexesha lenkqubo ye-CVD. Ngokunyuka kwexesha lokukhula, incopho malunga ne-103 eV yafudukela kumandla okubophelela asezantsi ngenxa yokuncipha kwemeko ye-oksijini ye-Si. Ngokusekelwe kubukho kunye nobuninzi besiginali se-carbon kwi-energy dispersive X-ray (EDX) mapping (Fig.  ), kwafunyaniswa ukuba nkqu emva kwemizuzu emi-5, ukukhula kwe-graphene kwenzeka ngempela phezu komhlaba we-SiO x , kwaye emva kwemizuzu engama-30, ukukhula kwadluliselwa kulo lonke ummandla womfanekiso, ngelixa i-Si kunye ne-O zazisasazwe ngokulinganayo. Umzali wobunzima be-graphene, kunye neziphumo zokuhlalutya kweRaman, ubuninzi bomhlaba, kunye nokudibanisa kwe-GB kwi-CVD yokukhula ixesha elahlukileyo zifingqwe kuTafile  . Ngokuphathelele kumhlaba, ukuncipha kwayo ngokunyuka kwexesha lokuphendula kuxhomekeke kwi-graphitization eqhubekayo apho imilawulo ye-graphene idibaniswa kwaye idibaniswa. Ukuhlalutya okuningiliziweyo kweRaman kunye ne-thermogravimetric (TG) analyses ziboniswa kwi-Supplementary Fig.  . 2a 23 24 25 2b 22 23 2c 25 2d–g 1 5   Ukuhlalutya kwe-graphene-ball ngexesha lokukhula kwayo.  –  >Ukuqwalaselwa kokukhula kwe-graphene ngexesha lenkqubo ye-CVD kusetyenziswa   >XRD,   >XPS kwicandelo le-C 1s, kunye   >IC PCS ye-Si 2p branch.  –  >I-EDX elemental mapping ngokubhekiselele kwi-C, O, kunye ne-Si emva kokuba  ,   >imizuzu emi-5 kunye  ,   >imizuzu engama-30 yokukhula kwe-graphene ukusuka kwi-SiO2 (iibha zesikali, 50 nm) a c a b c d g d e f g Ukugquma kwe-graphene ball kwikhatod ye-Ni-rich material Ngenxa yemorphology yayo enomlinganiselo womnwe, i-graphene iye yacingwa njengeyona nto ifanelekileyo yokugquma ukhuselo lwangaphandle lwezinto zekhatod ezinekhono eliphezulu. Nangona kunjalo, kwimeko yeendlela ezaziwayo zesisombululo , , ,  >esekelwe kwindlela kaHummer, ukufezekisa ukugquma okulinganayo kokuqulunqwa okulinganiselweyo kwe-graphene akufani ngenxa yokuqokelelana, okubangelwa yimibutho yombane enamandla phakathi kweentsika ze-graphene. Ngomzamo wokoyisa umba wokuqokelelana, indlela eyahlukileyo, njengokuchochothelwa kwe-graphite kusetyenziswa inkqubo yokucoca ibhola, iye yaziswa . Nangona kunjalo, le nkqubo idla ngokucotha (>6h) kwaye, ngokubaluleke ngakumbi, ingonakalisa i-crystallinity yezinto zomsingathi. Kufanele kuqatshelwe ukuba ukugquma kwe-carbon ye-amorphous ngeenkqubo ze-CVD akufani nezinto ze-Ni-rich oxide ,  >ngenxa yokuba iinkqubo ze-CVD zikhupha izinyitywili zentsimbi (TMs), ziphazamisa isakhiwo sokuqala sesitayile somsingathi. 26 27 28 29 30 31 32 Ngokungafaniyo, i-GB eyenziweyo kulo sifundo ingagqunywa phezu komhlaba we-LiNi0.6Co0.1Mn0.3O2 powder (ububanzi = ~10 µm) kwinqanaba elincinci le-1 wt% ngeendlela zeNobilta milling process. Inkqubo yokugquma ikwakhawuleza (~10 min kwi-3000 rpm). Ii-seeds ze-SiO x zidlala indima ebalulekileyo ekunika olu lugqumo lulinganayo kwiintlobo ezincinci zobunzima. Ii-seeds ze-SiO x ziqulatha i-57.5 wt% ye-GB (isiphumo se-TG kwi-Supplementary Fig.  ) kwaye kwinkqubo yokugquma, ubukho bazo buvumela i-GB ukuba ibenako ukubonelela ngamandla okubamba phezu komhlaba we-LiNi0.6Co0.1Mn0.3O2, idala idibaniso eqinisekileyo kwaye ingena ngaphakathi. Ukubonisa le nto yenzekayo, inkqubo efanayo yokugquma yenziwa kunye nomxube womzimba we-0.5 wt% SiO2 kunye no-0.5 wt% graphene. Lo mzekelo wawufumana umonakalo we-crystalline kw 5b

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Ukutshaja Ngokukhawuleza, Ubomi Obude: Inkohliso yeGraphene iPhucula iiBatere zeLithium

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