```html
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
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 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 Ukulungisa ipropati enye ngaphandle kokubeka esichengeni ezinye kuyinselele kumabhetri e-lithium-ion ngenxa yendalo yokutshintshiselana phakathi kweeparamitha eziphambili. Apha sixela inkqubo yokudala igraphene–silica assembly, ebizwa ngokuba yi-graphene ball. Isakhiwo sayo esinemilinganiselo emithathu enesitshizi se-silicon oxide nanoparticle esembindini sivumela ukuba i-1 wt% kuphela ye-graphene ball ihlanganiswe ngokulinganayo kwi-cathode ye-layered enobutyebi kwi-nickel nge-Nobilta milling ekhoyo. Ukugquma kwe-graphene-ball kuphucula ubomi besekethe kunye namandla okutshaja ngokukhawuleza ngokunciphisa iinkqubo ezingalunganga kunye nokubonelela ngeendlela ezisebenzayo zokudibanisa. I-graphene ball ngokwayo ikwanokusebenza njenge-anode material enomthamo omkhulu wokukwazi kwe-716.2 mAh g−1. I-full-cell equka i-graphene balls yonyusa ubungakanani bamandla ezi-27.6% xa ithelekiswa ne-cell elawulayo ngaphandle kwe-graphene balls, ibonisa amathuba okufumana i-800 Wh L−1 kuhlobo lwe-commercial cell, kunye nokugcinwa kwekhono eliphezulu le-78.6% emva kwesekethe ezingama-500 kwi-5C kunye ne-60 °C. Intshayelelo Ukuqhubeka kophuhliso lwe-lithium-ion batteries (LIBs) kukhokelele ekuphuculeni okumangalisayo kwiinkalo ezahlukeneyo zokusebenza kwazo, kubandakanya amandla ombane, amandla ombane, ubomi besekethe, kunye nokhuseleko. Ngoku, izixhobo eziphathwayo ze-IT zibonelela ngohlobo olukhulu lwezicelo ze-LIB, apho iinkcukacha zokusebenza ze-LIB zamva nje zanele , , . Nangona kunjalo, njengoko izithuthi zombane (EVs) zingene kwiimarike ze-LIB, iipropati eziphambili zombane zibeke imilinganiselo enzima ngakumbi; ngelixa amandla ombane aphezulu afunwa ukuze kunyuswe ibanga lokuhamba, ukunyusa i-kinetics yempendulo kufunwa ukutshaja ngokukhawuleza kunye nokusebenza komlinganiselo ophezulu. Ukhuseleko kunene yinto ebalulekileyo kwizicelo ze-EV. Inqanaba elikhulu libandakanya ukoyisa ubudlelwane bokutshintshiselana phakathi kwezi propati ziphambili; ngokuqhelekileyo akulula ukulungisa ipropati enye ngaphandle kokubeka esichengeni ezinye. 1 2 3 Ubuhlobo bokutshintshiselana obunjalo bubonakala kakhulu phakathi kwamandla ombane kunye nokutshaja ngokukhawuleza (okanye amandla ombane). Ngelixa ukusetyenziswa kwe-nanomaterials njengezithako ezisebenzayo ,  kunye nokudibanisa i-carbon nanomaterials , ,  njengeearhente zokudibanisa ziye zabonisa ukutshaja ngokukhawuleza ngokunciphisa umgama wokuhanjiswa kwe-ion kunye nokuchasana kwangaphakathi, uninzi lwezo zindlela lusefuna ukuphuculwa ngaphambi kokuba luqaliswe kwi-LIB technology yangoku. Iingxubeko ze-tap ze-nanomaterials ziphantsi kakhulu kunezo zeenqaku ezikhoyo, nto leyo eyenzakalisayo kumandla ombane, nto leyo eyinto ebalulekileyo kwizicelo ezininzi ze-LIB kune-gravimetric counterpart. Kwisimo esifanayo sokunciphisa ukuchasana kwangaphakathi, ukudibanisa i-carbon nanomaterials ezifana ne-graphene kubonise ukuba kusebenza ekunyeni ukudibanisa kwe-elektroni ye-electrodes ezisezingeni lelebhu. Nangona kunjalo, ukufezekisa ukusasazwa okulinganayo kwemali encinci (oko kukuthi, <3 wt%) ye-carbon nanomaterials kwinkqubo enkulu ye-slurry ayikabonakali. Ukuguqulwa kwezinto ezisebenzayo ezikhoyo ngokudibanisa izinto zangaphandle ,  okanye ulawulo lwe-stoichiometric , ,  inokunyusa ukusasazwa kwe-Li ions kwaye ke ngoko umgangatho wokutshaja wezinto ezisebenzayo ezikhoyo ezinobukhulu be-micrometer. Uninzi lwezo zindlela, nangona kunjalo, lusebenza ngexabiso lomthamo wokukwazi. 4 5 6 7 8 9 10 11 12 13 Ngaphandle kwamandla ombane kunye nokutshaja ngokukhawuleza, ukufezekisa ubomi obude besekethe, ngakumbi kubushushu obuphezulu (oko kukuthi, 60 °C), kuseyinjongo ye-LIBs ephuculweyo edibanisa izinto ze-electrode ezinomthamo omkhulu. Ngelixa izinto ze-oxide ezi-layered ezibutyebi kwi-nickel (Ni) kunye ne-Li zithathwa njengezinto zekhathode ezizayo ngenxa yomthamo wazo omkhulu wokukwazi xa kuthelekiswa nezo ze-LiCoO2 ezikhoyo, kuyaziwa ukuba ukuxubana kwe-cation okungaphethweyo ngexesha lokutshaja konakalisa isakhiwo esihleliyo sibe zi-spinel okanye ii-rock-salt structures, kunye neempendulo ezibi ezenzekayo kumphezulu we-electrode. Ngokuthathela ingqalelo imizamo eyenziwe ukuza kuthi ga ngoku, enye yezona zisisombululo zokwenyani ukuze kufumaneke ngokukhawuleza ukutshaja izinto zekhathode ezinomthamo omkhulu ngokusalahleka okuncinci kwamandla ombane kunye nobomi besekethe libandakanya ukufumana izinto zokukhusela ezidibanayo ezinokugqunywa ngokulinganayo kwizinto ezisebenzayo ngomthamo omncinci. Apha sixela i-graphene–silica (SiO   ) assembly, ebizwa ngokuba yi-graphene ball (GB), njenge-coating material yezinto zekhathode ezibutyebi kwi-nickel ezinomthamo omkhulu kunye ne-LIB anode material. Uninzi lwe-GB luquka isitshizi se-SiO   nanoparticle kunye neengqimba ezijikelezileyo ze-graphene, zidala isakhiwo esinobujikelezo obuthathu (3D) esifana ne-popcorn. Ii-nanoparticles ze-SiO   dlala indima ebalulekileyo kwiinkalo ezininzi, njengokuphepha ukwakheka komgca we-silicon carbide (SiC) kwi-interface ye-SiO   –graphene ngexesha lokukhula kwe-graphene, ukuqinisekisa ukugqunywa okulinganayo kwe-GB kwimathiriyeli ye-cathode, kunye nokubonelela ngomthamo omkhulu wokukwazi xa i-GB isetyenziswa njenge-anode material. Ukugqunywa okulinganayo kwe-GB kwi-Ni-rich layered cathode kuphucula ukhuseleko lwe-interfacial nge-electrolyte kunye nokudibanisa kwe-elektroni kuyo yonke i-electrode, kuphucula ubuchule besekethe kunye namandla okutshaja ngokukhawuleza kwe-cathode. Ukuthatha iingenelo ezizodwa ze-GB, i-full-cell equka i-cathode egqunywe yi-GB kunye ne-anode ye-GB ibonisa amathuba ombane ombane omkhulu osondele ku-800 Wh L−1 kwi-condition ye-commercial cell, kunye nokugcinwa kwekhono lama-78.6% emva kwesekethe ezingama-500 kwi-5C kunye ne-60 °C. x x x x Iziphumo Ukudala i-graphene ball Ukudala i-GB efana ne-popcorn, saphuhlisa inkqubo ye-chemical vapor deposition (CVD) yokukhula kwe-graphene. Igazi le-CH4 lalitsalwa kwi-furnace phambi kwe-SiO2 ii-nanoparticles ezinobubanzi obuyi-20–30 nm kwi-1000 °C. Kubushushu obu, i-CH4 iyahlulwa ukuvelisa ii-atom ze-hydrogen, ezinokuqalisa ukunciphisa i-SiO2 ibe yi-SiO   (  < 2). I-OH− ikwanemveliso ngokufanayo ngokusebenzisa le ngxaki ilandelayo: x x Impawu ephambili kule ngxaki kukuba i-SiO   emvelisayo ibonelela ngeendawo zokukhuthaza ukukhula kwe-graphene, kwaye i-OH− isebenza njenge-oxidant ephilileyo yokwenza lula ukwakheka kwe-graphitic carbon ukuya kwi-graphene , . Indima ye-oxidants ephilileyo ekwakheni i-graphitic carbon iye yachazwa kutsha nje  ngendlela yokuba, ngaphandle kwe-oxidant ephilileyo, ukwakheka kwe-carbon engabonakaliyo kubaluleke kakhulu. Ngokwenene, ukukhula okungekhawulezayo kwe-graphene kusetyenziswa ii-catalysts zemichiza kuyaziwa ukuba kwenzeka ngendlela efanayo , , , apho i-oksijeni eseleyo kumphezulu we-metal ibangela impendulo ekhethekayo ukuya ekwakheni i-graphitic carbon. Ubukho be-oxidant ephilileyo bukwenza ukuphephe ukwakheka komgca we-silicon carbide (SiC) kumphezulu we-SiO   kuba i-oxidant ithintela ukuncitshiswa kwe-Si ukuya ekwakheni i-SiC . x 14 15 16 17 18 19 x 19 Kuhlobo lwethu lwemichiza olusekelwe ekusetyenzisweni okupheleleyo kwe-CH4, kubushushu obuphantsi kune-900 °C, i-graphene yayingakhuli kakhulu. Ngokuchaseneyo, kwi-1050 °C nangaphezulu, ukukhula kwe-graphene kwaba nkulu kakhulu ukuya ekwakheni i-graphite (Supplementary Fig.  ). Ngokukodwa, ubushushu bokukhula obu-1000 °C bungaphantsi kunezo (1100–1400 °C) zihlala zisetyenziselwa ukukhula kwe-graphene okusekelwe kwi-CVD okusekelwe kwi-Si kunye ne-SiO2 substrates ngaphandle kwe-metal catalysts , , . Indima ebalulekileyo yendawo yokukhula yachazwa ngovavanyo lolawulo (Supplementary Fig.  ); kulandela iinkqubo eziqhelekileyo ze-CVD ezisebenzisa ii-catalysts zemichiza, i-CH4 kunye ne-H2 zalitsalwa kumlinganiselo wokuhamba ngevolumu we-3:7 kwi-1000 °C. Ngokuba ukuhlakuka kwe-CH4 kwathintelwa bubuninzi be-H2, ukukhula kwe-graphene kwakucaphukisa kakhulu, kubonisa ukubaluleka kokusetyenziswa okupheleleyo kwe-CH4 ekukhuleni okusebenzayo kwe-graphene kwinqanaba lethu lokudala. Ngokubanzi, ukukhethwa kwezinto eziphendulayo kunye nobushushu bokuphendula kuhlobo lwangoku lwemichiza yahlukile kwi-counterparts ezisekelwe kwi-CVD ezisebenzisa ii-catalysts zemichiza kwaye idlala indima ephambili ekudaleni i-graphene–SiO   assembly enesakhiwo esinemilinganiselo emithathu. 1 20 21 22 2 x Umgangatho wokukhula kwe-graphene yachazwa ngakumbi ngoluhlu lovavanyo olongezelelweyo. I-scanning electron microscope (SEM) (Supplementary Fig.  ) kunye ne-transmission electron microscope (TEM) analysis (Fig.  ) eyenziwa ngexesha lenkqubo ye-CVD ibonisa utshintsho ekukhuleni nasekukhangelekeni kwe-graphene. Emva kwemizuzu emi-5 yenkqubo ye-CVD, i-film ye-graphene enobubanzi obuyi-2–3 layer yabonakala ngokungacacanga kumphezulu we-SiO2 (Fig.  , e), kunye nombala womgubo ojika ube mnyama (Supplementary Fig.  ). Ukukhula kwe-graphene kwaba ngakumbi emva kwemizuzu engama-30 yenkqubo ye-CVD, apho isakhiwo se-3D sheet sabonakala ngokucacileyo (Fig.  , f). Umfanekiso we-TEM ophezulu (Fig.  ) ubamba ulungelelwaniso lwe-atomic hexagonal kwicandelo le-graphene, elibonisa ipleyini yalo eyintloko. Emva kwemizuzu engama-30, kwakuthathelwa ingqalelo ukuba ubukhulu be-SiO2 ii-nanoparticles buye bancipha ukusuka kwi-28.2 ukuya kwi-15.3 nm ngokomndilili (Supplementary Fig.  ). Oku kwenzeka kuba ukukhula kwe-graphene kubandakanya ukuncitshiswa kwe-SiO2 okuchazwe ngasentla kunye nokwakheka kwe-OH− emva koko. Ngoko ke, ukukhula okupheleleyo kwe-graphene kufana nokukhula kwe-popcorn kwisidenge esinobujikelezo obuthathu, esiveliswe ngenxa yee-kernels zangokuphambili (Fig.  ). 3a–f 1a–g 1b 3g 1c 1g 4 1h   Ukukhula kwe-graphene ukusuka kwi-SiO2 ii-nanoparticles.  –  I-TEM characterization   phambi kokukhula kwe-CVD,   emva kwemizuzu emi-5 yokukhula, kunye   emva kwemizuzu engama-30 yokukhula (iimitha zesikali, ii-nm ezingama-50).  –  Imifanekiso yazo ehambelanayo (iimitha zesikali, ii-nm ezili-10).   Umfanekiso ophezulu we-graphene emva kwemizuzu engama-30 yokukhula kunye nombono wayo wenqanaba le-atom ukusuka kwibhokisi emhlophe (inset) (imitha yesikali, i-2 nm).   Umboniso ografiki wokukhula kwe-graphene okufana ne-popcorn ukusuka kwi-SiO2 ii-nanoparticles a c a b c d f g h Ukukhula kwe-graphene kwachazwa ngakumbi ngoluhlu lovavanyo olongezelelweyo. I-X-ray diffraction (XRD) spectra efunyenwe ngexesha lokukhula ibonisa ukuba njengoko inkqubo ye-CVD iqhubeka, iintsimbi kwi-2  = 26.44° kunye ne-44°, ehambelana ne-planes (002) kunye ne-(101) ze-graphite, zikhule rhoqo (Fig.  ), ibuyisela kwakhona ukwakheka kwe-graphitic carbon , , . Ukukhula kwe-graphene kwabonakala nangent simbini kwi-284.5 kunye ne-291.5 eV kwicandelo le-C 1s le-X-ray photoelectron spectroscopy (XPS) analysis (Fig.  ) , . Intsimbi kwi-284.5 eV inikezelwe kwiibond C–C kunye ne-C = C, ebonakale kakhulu emva kwemizuzu engama-30 yokukhula ngenxa yokwakheka kwe-graphitic carbon. Iintsimbi eziqhubekayo ze-XPS kwicandelo le-Si 1s le-XPS analysis (Fig.  ) ziyaqinisekisa kwakhona  ukuncitshiswa kwe-SiO2 ngexesha lenkqubo ye-CVD. Ngokwanda kwexesha lokukhula, intsimbi ekufutshane ne-103 eV yahanjiswa kwiimbekiselo eziphantsi zokubopha ngenxa yokuncipha kwenqanaba lokunqanda i-Si. Ngokusekelwe kubukho kunye namandla omqondiso we-carbon kwi-energy dispersive X-ray (EDX) mapping (Fig.  ), kwafunyaniswa ukuba nangemva kwemizuzu emi-5, ukukhula kwe-graphene kwenzeke kumphezulu we-SiO   , kwaye emva kwemizuzu engama-30, ukukhula kwabeka kuyo yonke indawo yemifanekiso, ngelixa i-Si kunye ne-O zazisasazeka ngokulinganayo. Isiqingatha sobunzima se-graphene, kunye neziphumo zovavanyo lweRaman, umthamo womphezulu, kunye nokudibanisa kwe-GB kwi-CVD yokukhula ixesha elahlukileyo zishwankathelwe kwiTafile  . Ngokubhekisele kumthamo womphezulu, ukuncipha kwayo ngokwanda kwexesha lokuphendula kunikezelwa ekukhuleni okungapheliyo apho iingqimba ze-graphene zidibanisa kwaye zihlanganiswa. Ukuvavanywa kweRaman kunye ne-thermogravimetric (TG) zokhokho ziboniswa kwi-Supplementary Fig.  . θ 2a 23 24 25 2b 22 23 2c 25 2d–g x 1 5   Uhlalutyo lwe-graphene-ball ngexesha lokukhula kwayo.  –  Ukubeka iliso ekukhuleni kwe-graphene ngexesha lenkqubo ye-CVD kusetyenziswa   XRD,   XPS kwicandelo le-C 1s, kunye   XPS icandelo le-Si 2p.  –  I-EDX elemental mapping ngokubhekisele kwi-C, O, kunye ne-Si emva kwemizuzu emi-5  ,   kunye nemizuzu engama-30  ,   ukukhula kwe-graphene kwi-SiO2 (iimitha zesikali, ii-nm ezingama-50) a c a b c d g d e f g Ukugqunywa kwe-graphene ball kwi-Ni-rich cathode material Ngenxa yesimo sayo semorphology esineengqimba ezimthubi, i-graphene iye yacingwa njengeyona nto ilungileyo yokugquma kwendawo ye-cathode materials ezinomthamo omkhulu we-layered. Nangona kunjalo, kwimeko yeendlela zesisombululo ezaziwayo , , ,  esekelwe kwindlela ka-Hummer, ukufezekisa ukugquma okulinganayo ngomthamo olinganiselweyo we-graphene akulula ngenxa yokuqokelelana, okubangelwa yintsebenziswano enamandla ye-electrostatic phakathi kweengqimba ze-graphene. Ngomzamo wokoyisa ingxaki yokuqokelelana, indlela eyahlukileyo, njengokutyumza i-graphite kusetyenziswa inkqubo ye-ball-milling, iye yaziswa . Nangona kunjalo, le nkqubo idla ngokuba ngocaphulo (>6 h) kwaye, okubaluleke kakhulu, ingalimaza ukuchongwa kwe-host material. Kufanele kwakhona kuphawulwe ukuba ukugquma kwe-carbon okungabonakaliyo ngeenqubo ze-CVD ayisebenzi kwizinto ze-oxide ezinobutyebi kwi-nickel ,  kuba iinkqubo ze-CVD zikhuphela i-transition metals (TMs), ziphazamisa isakhiwo sokuqala se-host material. 26 27 28 29 30 31 32 Ngokuchaseneyo, i-GB edalwe kulo sifundo ingagqunywa kumphezulu we-LiNi0.6Co0.1Mn0.3O2 powder (ubukhulu = ~10 µm) ngomthamo omncinci we-1 wt% nge-Nobilta milling process ephilileyo. Inkqubo yokugquma ikwangokukhawuleza kakhulu (~10 min kwi-3000 rpm). Ii-seeds ze-SiO   dlala indima ebalulekileyo ekwenzeni ukuba esi sigqumi silingane ngomthamo ophantsi. Ii-seeds ze-SiO   zibonelela nge x x

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Ukutshaja Okukhawulezayo, Ubomi Obude: I-Graphene Trick Ephucula iiBhetri zeLithium

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