
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 Ababhali: 
 
 
 
 
 
 
 
 
 
 
 In Hyuk Son Jong Hwan Park Seongyong Park Kwangjin Park Sangil Han Jaeho Shin Seok-Gwang Doo Yunil Hwang Hyuk Chang Jang Wook Choi Isishweshwe Ukuphucula ipropati enye ngaphandle kokuyeka ezinye kunzima kwiibhetri ze-lithium-ion ngenxa yesiphumo sokulinganisa phakathi kweeparameter eziphambili. Apha sibika inkqubo yokufudumeza ngokusebenzisa umphunga ukuvelisa indibaniselwano ye-graphene–silica, ebizwa ngokuba yi-graphene ball. Isakhiwo sayo esihleli-ntathu esinombane wesithili sesilicon oxide nanoparticle sivumela i-1% kuphela ye-graphene ball ukuba ihlanganiswe ngokulinganayo kwikhatode enebhodi engqonge i-nickel-rich ngeNobilta milling enokubuyiselwa. Isikhewu se-graphene-ball siphucula ubomi besekethe kunye nokukwazi ukutshaja ngokukhawuleza ngokunciphisa iziphumo ezibi kunye nokubonelela ngeendlela ezisebenzayo zokudibanisa. I-graphene ball ngokwayo ikwasebenza njengemateriali ye-anode enomthamo omkhulu we-716.2 mAh g−1. Iseli epheleleyo ebandakanya ii-graphene balls yonyusa idensity yamandla evolumetric ngo-27.6% xa ithelekiswa neseli yolawulo ngaphandle kwama-graphene balls, ibonisa ukubakho kokufumana i-800 Wh L−1 kwisethingi yeseli eshishinayo, kunye nokukwazi ukugcina i-78.6% yamandla emva kwesekethe ezingama-500 kwi-5C kunye ne-60 °C. Intshayelelo Ukuqhubela phambili kophuhliso lweebhetri ze-lithium-ion (LIBs) kuye kwabonisa ukuphucuka okumangalisayo kwiinkalo ezahlukeneyo zokusebenza kwazo, kubandakanya idensity yamandla, idensity yamandla, ubomi besekethe, kunye nokhuseleko. Ngoku, izixhobo ze-IT eziphathekayo zibonelela ngoluhlu olukhulu lwezicelo ze-LIB, apho iinkonzo zokusebenza ze-LIB ezisemgangathweni zigqibelele , , . Nangona kunjalo, njengoko izithuthi zombane (EVs) ziye zangena kwiimarike ze-LIB, iipropati eziphambili zamakhemikhali zibeke imigangatho enzima; ngelixa iidensity eziphezulu zamandla zifunwa ukwandisa ibanga lokuhamba, i-kinetics yokuphendula eyongeziweyo ifunwa ukutshaja ngokukhawuleza kunye nokusebenza okuphezulu. Ukhuseleko ngokuqinisekileyo yinto ebalulekileyo kwizicelo ze-EV. Ingxaki enkulu ikwintshukumo yobudlelwane phakathi kwezi properties ziphambili; kunzima ukonyusa ipropati enye ngaphandle kokubeka enye esichengeni. 1 2 3 Ubuhlobo obunjalo buchazwa ngokukodwa phakathi kwedensity yamandla kunye nokutshaja ngokukhawuleza (okanye amandla aphezulu). Ngelixa ukusetyenziswa kwezinto ezincinci njengezinto ezisebenzayo ,  kunye nokudibanisa izinto ezincinci ze-carbon , ,  njengeearhente zokudibanisa zibonise ukutshaja ngokukhawuleza ngokunciphisa ibanga lokuhamba kwe-ion kunye nokumelana kwangaphakathi, uninzi lwezi ndlela lisafuna ukuphuculwa ngaphambi kokuba lusetyenziswe kwiteknoloji ye-LIB yangoku. I-tap-densities zezinto ezincinci ziphantsi kakhulu kunezecashu zeqhekeza le-micro, nto leyo eyonakalisa idensity yamandla evolumetric, into ebalulekileyo kwiisicelo ezininzi ze-LIB kune-gravimetric counterpart. Ngokufanayo, ukunciphisa ukumelana kwangaphakathi, ukudibanisa izinto ezincinci ze-carbon ezifana ne-graphene kubonise ukuba kuyasebenza ekwandiseni ukudibanisa kombane kwii-electrodes zesayensi. Nangona kunjalo, ukufezekisa ukusasazeka okulinganayo komxholo omncinci (oko kukuthi, <3 wt%) wezinto ezincinci ze-carbon kwinkqubo yokuxuba enkulu ayikaboniswa. Ukuguqulwa kwezinto ezisebenzayo ezikhoyo ngokudibanisa ii-elementi zangaphandle ,  okanye ulawulo lwe-stoichiometric , ,  >ngokubonelela ngcono kwikhono lokugcwalisa izinto ezisebenzayo ziqhekeza zemicro. Uninzi lwezi ndlela, nangona kunjalo, lusebenza ngenxa yombane omkhulu. 4 5 6 7 8 9 10 11 12 13 Ngaphezu koko, ngaphandle kwedensity yamandla kunye nokutshaja ngokukhawuleza, ukufumana ubomi obude besekethe, ngakumbi kubushushu obuphezulu (oko kukuthi, 60 °C), kusengumngeni kwi-LIBs ezihlaziyiweyo ezibandakanya izinto zekhatodi ezinomthamo ophezulu. Ngelixa izinto ezisebenzayo ezinika-nickel (Ni) kunye ne-lithium-rich layered oxide zithathwa njengezinto zekhatodi ezizayo ngenxa yee-capacities zazo ezizodwa ezinkulu kunezecashu ze-classical LiCoO2, kuyaziwa ukuba ukuxubana kwe-cation okungaphethwayo ngexesha lokutshaja kuyonakalisa isakhiwo se-layered ukuya kwi-spinel okanye i-rock-salt structures, kunye neziphumo ezibi kwindawo ye-electrode. Ukubhekisisa imizamo eyenziweyo ukuza kuthi ga ngoku, enye yezona zixazululo zibalulekileyo zokufumana ngokukhawuleza ukutshaja izinto zekhatodi ezinenqanaba elincinci lamandla kunye nobomi besekethe yile yokufumana izinto zokukhusela ezidibanayo ezinokubonelelwa ngokulinganayo kwizinto ezisebenzayo ngomxholo omncinci. Apha sibika indibaniselwano ye-graphene–silica (SiO   ), ebizwa ngokuba yi-graphene ball (GB), njengento yokubonelela ngeekhatodi ezine-nickel-rich ezinomthamo omkhulu kunye nemateriali ye-anode ye-LIB. I-GB nganye ibandakanya isithili sesilicon oxide nanoparticle kunye nemilambo ye-graphene ejikelezileyo, edibanisa isakhiwo esihleli-ntathu (3D) esifana ne-popcorn. Izithili ze-SiO   nanoparticle zidlalwa indima ebalulekileyo kwiinkalo ezininzi, njengokuphepha ukudala umaleko we-silicon carbide (SiC) kumaleko we-SiO   –graphene ngexesha lokukhula kwe-graphene, ukuqinisekisa ukubonelelwa okulinganayo kwe-GB kwimateriali yekhatodi, kunye nokubonelela nge-capacity enkulu xa i-GB isetyenziswa njengemateriali ye-anode. Ukubonelelwa okulinganayo kwe-GB kwikhatodi enebhodi engqonge i-nickel-rich kuphucula ukuzinza kwendawo kunye ne-electrolyte kunye nokudibanisa kombane kwi-electrode, kuphucula kakhulu ukugcinwa kwe-cyclability kunye nokukwazi ukutshaja ngokukhawuleza kwekhatodi. Ukuthatha izibonelelo ezizodwa ze-GB, iseli epheleleyo ebandakanya ikhatodi ye-GB-coated kunye ne-anode ye-GB ibonisa ukubakho kwedensity yamandla evolumetric esondeleyo kwi-800 Wh L−1 kwisimo seseli eshishinayo, kunye nokugcinwa kwe-78.6% yamandla emva kweesekethe ezingama-500 kwi-5C kunye ne-60 °C. x x x Iziphumo Ukuveliswa kwe-graphene ball Ukvelisa i-GB efana ne-popcorn, sadala inkqubo yokufudumeza ngomphunga (CVD) yokukhula kwe-graphene. Igsi ye-CH4 yayibonelelwa kwi-furnace ngobukho bezithili ze-SiO2 nanoparticle ezine-diameter ye-20–30 nm kwi-1000 °C. Kubushushu obuyi-1000 °C, i-CH4 iyahlula ukudala ii-atom ze-hydrogen, ezinokuthi kamva zibuyisele i-SiO2 kwi-SiO   (   < 2). I-OH− iyavela kwithuba elilandelayo: x x Isici esiphambili kulempendulo kukuba i-SiO   evelisiweyo ibonelela ngeendawo zokukhuthaza ukukhula kwe-graphene, kwaye i-OH− isebenza njenge-oxidant ethambileyo ukuze kukhuthazwe ukubunjwa kwe-carbon yegraphitic ukuya kwi-graphene , . Indima ye-oxidants ethambileyo ekubunjweni kwe-carbon yegraphitic iye yachazwa kutshanje  ngendlela yokuba, ngaphandle kwe-oxidant ethambileyo, ukubunjwa kwe-carbon engagqibekanga kuye kwanda. Ngapha koko, kubukho be-oxidant ethambileyo, kwafunyaniswa ukuba impendulo eya kwi-CO okanye i-CO2 ifunwa kakhulu kwi-carbon atoms ezabe kungenjalo zivelise i-carbon engagqibekanga. Ngempela, ukukhula okulula kwe-graphene kusetyenziswa ii-catalysts zem allowNull zaziwa ukuba zenzeka ngendlela efanayo , , , apho i-oxygen esele ikumhlaba we-metal ikhuthaza impendulo eya kubunjwa kwe-carbon yegraphitic. Ubukho be-oxidant ethambileyo bukhusela ukubunjwa komaleko we-silicon carbide (SiC) kumhlaba we-SiO   ngenxa yokuba i-oxidant ithintela ukubuyiselwa kwe-Si ekubunjweni kwe-SiC . x 14 15 16 17 18 19 x 19 Kwintshukumo yethu yempendulo esekwe ekusetyenzisweni okukhethekileyo kwe-CH4, kubushushu obungaphantsi kwe-900 °C, i-graphene yayingakhuli kancinci. Ngokungafaniyo, kwi-1050 °C nangaphezulu, ukukhula kwe-graphene kuye kwaba ngathi kunyusa kakhulu ukubunjwa kwe-graphite (Supplementary Fig.  ). Ngokukodwa, ubushushu bokukhula be-1000 °C bungaphantsi kunezo (1100–1400 °C) zihlala zisetyenziselwa ukukhula kwe-graphene esekwe kwi-CVD esekwe kwi-Si kunye ne-SiO2 substrates ngaphandle kwe-metal catalysts , , . Indima ebalulekileyo yendibano yokukhula ichazwe ngovavanyo lolawulo (Supplementary Fig.  ); ukulandela iinkqubo eziqhelekileyo ze-CVD kusetyenziswa ii-catalysts zem allowNull, i-CH4 kunye ne-H2 yayibonelelwa kwi-3:7 volumetric flow ratio kwi-1000 °C. Ngenxa yokuba ukuhlukana kwe-CH4 kuthintelwe kakhulu kwi-H2, ukukhula kwe-graphene kwakukukhula kancinci, kubonisa ukubaluleka kokusetyenziswa okukhethekileyo kwe-CH4 kwisikhululo esisebenzayo sokukhula kwe-graphene kwiprotocol yethu yokuvelisa. Ngokubanzi, ukhetho lwezinto ezisebenzayo kunye nobushushu bempendulo kwintshukumo yempendulo yangoku iyahluka kwiindawo zangaphambili ze-CVD ezisebenzisa ii-catalysts zem allowNull kwaye idlala indima ebalulekileyo ekuveliseni indibaniselwano ye-graphene–SiO   kunye nesakhiwo esihleli-ntathu. 1 20 21 22 2 x Uvavanyo oluthile lwe-scanning electron microscope (SEM) (Supplementary Fig.  ) kunye ne-transmission electron microscope (TEM) (Fig.  ) eyenziwa ngexesha lenkqubo ye-CVD ibonisa utshintsho ekukhuleni kwe-graphene kunye nemorphology. Emva kwemizuzu emi-5 yenkqubo ye-CVD, ifilimu ye-graphene enobubanzi obu-2–3 yabonakala kancinci kumphezulu we-SiO2 (Fig.  , e), kunye nombala womgubo ojika ube ngumnyama (Supplementary Fig.  ). Ukukhula kwe-graphene kwabonakala kakhulu emva kwemizuzu engama-30 yenkqubo ye-CVD, apho imorphology ye-sheet ye-3D ibonakala ngokucacileyo (Fig.  , f). Umfanekiso we-TEM wokwandiswa okuphezulu (Fig.  ) ubamba ukuhlelwa kwe-atomic ye-hexagonal kwicandelo le-graphene, elibonisa imbono yalo eyinhloko. Emva kwemizuzu engama-30, kwaphawulwa kwakhona ukuba ubukhulu bezithili ze-SiO2 nanoparticle banciphe ukusuka kwi-28.2 ukuya kwi-15.3 nm ngokomndilili (Supplementary Fig.  ). Oku kwenzeka kuba ukukhula kwe-graphene kubandakanya ukubuyiselwa kwe-SiO2 kwangaphambili kunye nokubunjwa kwe-OH− emva koko. Ngoko ke, ukukhula okubanzi kwe-graphene kufana nokukhula kwe-popcorn okwandayo kwisakhiwo esinobubanzi obuyi-3D, esiveliswa ngenxa yeziphumo zekernel zoqobo (Fig.  ). 3a–f 1a–g 1b 3g 1c 1g 4 1h   Ukukhula kwe-Graphene ukusuka kwi-SiO2 nanoparticles.  –  Uvavanyo lwe-TEM   ngaphambi kokukhula kwe-CVD,   emva kwemizuzu emi-5 yokukhula, kunye   emva kwemizuzu engama-30 yokukhula (imilinganiselo yomgca, 50 nm).  –  Imifanekiso yabo ephuculiweyo ngokulandelelanayo (imilinganiselo yomgca, 10 nm).   Umbono ophuculweyo kakhulu we-graphene emva kwemizuzu engama-30 yokukhula kunye nombono wayo wenqanaba le-atom ukusuka kwibhokisi emhlophe (inset) (umlinganiselo womgca, 2 nm).   Umzekeliso womfanekiso wokukhula kwe-graphene efana ne-popcorn ukusuka kwi-SiO2 nanoparticles a c a b c d f g h Ukukhula kwe-graphene kuye kwachazwa ngokuphandileyo ngoluhlu lovavanyo olongezelelweyo. Iimilo ze-X-ray diffraction (XRD) ezifunyenwe ngexesha lokukhula zibonisa ukuba njengoko inkqubo ye-CVD iqhubeka, iinqaku kwi-2  = 26.44° kunye ne-44°, ezihambelana neendlela (002) kunye ne-(101) ze-graphite, zakhula ngokuqhubekayo (Fig.  ), ziqinisekisa kwakhona ukubunjwa kwe-carbon yegraphitic , , . Ukukhula kwe-graphene kubonakaliswe kwakhona kwiinqaku kwi-284.5 kunye ne-291.5 eV kubandakanya i-C 1s ye-X-ray photoelectron spectroscopy (XPS) uvavanyo (Fig.  ) , . Inqaku kwi-284.5 eV libhekiswe kwi-C–C kunye ne-C = C bonds, eyavela kakhulu emva kwemizuzu engama-30 yokukhula ngenxa yokubunjwa kwe-carbon yegraphitic. Iinqaku ze-XPS eziqhubekayo kubandakanya i-Si 1s ye-XPS uvavanyo (Fig.  ) ziqinisekisa kwakhona  ukubuyiselwa kwe-SiO2 ngexesha lenkqubo ye-CVD. Ngokukhula kobude bokukhula, inqaku elikufutshane ne-103 eV lahla kwiibinding energies eziphantsi ngenxa yokuncipha kwenqanaba lokubuyisela i-Si. Ngokusekelwe kubukho kunye namandla omqondiso we-carbon kwi-energy dispersive X-ray (EDX) mapping (Fig.  ), kwafunyaniswa ukuba naku emva kwemizuzu emi-5, ukukhula kwe-graphene kwenzeka kumphezulu we-SiO   , kwaye emva kwemizuzu engama-30, ukukhula kuye kwanda kuyo yonke indawo yesithombe, ngelixa i-Si kunye ne-O zihlala zisasazekile. Umxholo wobunzima we-graphene, kunye neziphumo zovavanyo lwe-Raman, ummandla othile osembindini, kunye nokudibanisa kwe-GB kubude obuhlukeneyo bokukhula kwe-CVD kucatshangelwe kwiThebhileyo  . Ngokuphathelele kumandla ommandla osembindini, ukuncipha kwayo ngokukhula kobude kuxhomekeke kwigrapfitization eqhubekayo apho imilambo ye-graphene ihlanganiswa kwaye iqokelelana. Iimilo ze-Raman kunye ne-thermogravimetric (TG) zovavanyo zinikezelwa 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.  –  Ukuqwalasela ukukhula kwe-graphene ngexesha lenkqubo ye-CVD kusetyenziswa   XRD,   XPS kubandakanya i-C 1s, kunye   XPS i-Si 2p branch.  –  I-EDX elemental mapping malunga ne-C, O, kunye ne-Si emva kwemizuzu emi-5  ,   kunye nemizuzu engama-30  ,   ukukhula kwe-graphene ukusuka kwi-SiO2 (imilinganiselo yomgca, 50 nm) a c a b c d g d e f g Ukubonelelwa kwe-graphene ball kwikhatodi enebhodi enebhodi ye-nickel-rich Ngenxa yemorphology yayo enemigangatho enobubanzi obuyibunye, i-graphene iye yacingwa njengeyona nto ifanelekileyo yokubonelela ngeekhatodi ezinomthamo omkhulu onama-layered. Nangona kunjalo, kwimeko yezi nkqubo zesisombululo ezaziwayo , , ,  esekwe kwindlela kaHummer, ukufumana ukubonelelwa okulinganayo kunomxholo olinganiselweyo we-graphene akulula ngenxa yokudibana, okubangelwa kukudibana kweekhemikhali phakathi kwezikhwama ze-graphene. Ngomzamo wokoyisa umba wokudibana, indlela eyahlukileyo, njengokugqobhoza kwe-graphite kusetyenziswa inkqubo ye-ball-milling, liye laboniswa . Nangona kunjalo, le nkqubo ihlala iyacothela (>6h) kwaye, okubaluleke kakhulu, ingonakalisa ukumila kwe-crystal yomathambiso olusingelweyo. Kufanele kuphawulwe kwakhona ukuba ukubonelelwa kwe-carbon engagqibekanga ngeenkqubo ze-CVD akufanelekanga kwizinto ze-nickel-rich oxide ,  ngenxa yokuba iinkqubo ze-CVD zithatha i-metal yeqela (TMs), ziphazamisa imila yoqobo yomathambiso olusingelweyo. 26 27 28 29 30 31 32 Ngokungafaniyo, i-GB egciniweyo kulo sifundo ingabonelelwa kumphezulu womgubo ocacileyo we-LiNi0.6Co0.1Mn0.3O2 (ubukhulu = ~10 µm) kumxholo omncinci we-1% nge-Nobilta milling process ethambileyo. Inkqu

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Ukutshaja Okukhawulezayo, Ubomi Obude: Inkohliso yeGraphene Ephucula iiBatri zeLithium

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