
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 
 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 Isishwawulo Ukuphucula omnye umsebenzi ngaphandle kokugxeka abanye kunzima kubathengi bebhetri be-lithium-ion ngenxa yendlela yokurhweba phakathi kwezinto eziphambili. Apha sibika inkqubo yokufudumala ngomphunga ukukhulisa umhlanganiso we-graphene–silica, obizwa ngokuba yi-graphene ball. Isakhiwo sayo esinobukhulu obuthathu kunye neziko le-silicon oxide nanoparticle likuvumela ukuba i-graphene ball enye eyi-1 wt% igaleleke kakuhle kwikhatodi elihamba phambili eligxile kwi-nickel nge-Nobilta milling enokukhula. Ukugaleleka kwe-graphene-ball kuphucula ubomi bebhetri kunye nokukwazi ukutshaja ngokukhawuleza ngokunciphisa ukusabela okubi kunye nokubonelela ngeendlela zokuhambisa izinto ngendlela efanelekileyo. I-graphene ball ngokwayo ikwasebenza njengento yokuhlawula i-anode enomthamo omkhulu we-716.2 mAh g−1. I-full-cell efaka i-graphene balls yonyusa ubuninzi bamandla nge-27.6% xa ithelekiswa ne-cell elawulayo ngaphandle kwe-graphene balls, ibonisa ukwenzeka kokufumana i-800 Wh L−1 kwisetingi ye-cell yokuthengisa, kunye nokuhlangana okuphezulu kwe-78.6% yokugcinwa komthamo emva kwe-500 cycles kwi-5C kunye ne-60 °C. Intshayelelo Ukuqhubeka kophuhliso lweebhetri ze-lithium-ion (LIBs) kuye kwabangela ukuphucuka okukhulu kwezinto ezahlukeneyo zokusebenza, kubandakanya ubuninzi bamandla, ubuninzi bamandla, ubomi bebhetri, kunye nokhuseleko. Ngoku, izixhobo ze-IT eziphathwayo zibonelela ngengxenye ebalulekileyo yezicelo ze-LIB, apho imilinganiselo yokusebenza ye-LIBs yangoku ihlangatyezwana kakuhle , , . Nangona kunjalo, njengoko izithuthi zombane (EVs) zingene kwiimarike ze-LIB, izinto eziphambili zombane zibeke imigangatho enzima ngakumbi; ngelixa ubuninzi bamandla aphezulu bufuna ukwandiswa kokuhamba kweekhilomitha, i-kinetics yokusabela eyonyusiweyo ifunwa ukutshaja ngokukhawuleza kunye nokusebenza okuphezulu kwesantya. Ukhuseleko ngokuqinisekileyo yenye into ebalulekileyo kwizicelo ze-EV. Umceli mngeni omkhulu ulele ekoyiseni ubudlelwane bokutshatisa phakathi kwezi mpawu ziphambili; ngokuqhelekileyo akulula ukwenza ngcono umsebenzi omnye ngaphandle kokugxeka abanye. 1 2 3 Olu budlelwane bokutshatisa bubonakala ngokukodwa phakathi kobuninzi bamandla kunye nokutshaja ngokukhawuleza (okanye amandla amandla). Ngelixa ukusetyenziswa kwezinto eziphilayo njengezinto eziphambili ,  kunye nokufakwa kwezinto eziphilayo ezine-carbon , ,  njengeearhente zokuhambisa nazo zibonise ukutshaja okungcono ngokunciphisa umgama wokusasazeka kwe-ion kunye nobuchule bangaphakathi, uninzi lwezi ndlela zisefuna ukuphuculwa ngaphambi kokuba zisebenze kwi-LIB technology yangoku. Ii-tap-densities zezinto eziphilayo ngaphantsi kakhulu kunezi zeekhonkco zemicro-particle, eziyimfuneko kubuninzi bamandla omthamo, nto leyo ebalulekileyo kwezinye izicelo ze-LIB kune-gravimetric counterpart. Kwisimo esifanayo sokunciphisa ubuchule bangaphakathi, ukudityaniswa kwezinto eziphilayo ze-carbon ezinjenge-graphene kubonakale kusebenza ekwandiseni ukuhanjiswa kombane kwe-electrode ze-lab-scale. Nangona kunjalo, ukufezekisa ukuhanjiswa okufanayo komxholo omncinci wesantya (oko kukuthi, <3 wt%) wezinto eziphilayo ze-carbon kwinkqubo enkulu yokuxutywa ayikaboniswa. Ukulungiswa kwezinto ezichanekileyo ezichanekileyo ngokudibanisa izinto ezahlukeneyo ,  okanye ulawulo lwe-stoichiometric , ,  ngokunjalo inokwandisa ukusasazeka kwe-Li ions kwaye ngaloo ndlela isantya sokutshaja sezinto eziqhelekileyo ezinobubanzi be-micrometer. Uninzi lwezi ndlela, nangona kunjalo, lusebenza ngexabiso lobuninzi bomthamo. 4 5 6 7 8 9 10 11 12 13 Ngaphezu koko, ngaphandle kobuninzi bamandla kunye nokutshaja ngokukhawuleza, ukufumana ubomi obude bebhetri, ngakumbi kubushushu obuphezulu (oko kukuthi, 60 °C), kuseyindawo yomngeni kuma-LIBs aphambileyo afaka izinto zokuhlawula ezine-capacity ephezulu. Ngelixa izinto ze-oxide ezihamba phambili ezine-nickel (Ni) kunye ne-Li ziqwalaselwa njengezinto zokuhlawula ezizayo ngenxa yemithamo yazo ephezulu xa kuthelekiswa nezo ziqhelekileyo ze-LiCoO2, kuyaziwa ukuba ukudibanisa kwe-cation okungalindelekanga ngexesha lokutshaja kuyonakalisa isakhiwo esihambelanayo sibe yi-spinel okanye i-rock-salt structures, kunye nokusabela okubi kumphezulu we-electrode. Ukujonga imizamo eyenziweyo ukuza kuthi ga ngoku, enye yeendlela zokwenyani zokufumana ngokukhawuleza ukutshaja izinto zokuhlawula ngokuphulukana komthamo wamandla kunye nobomi bebhetri libandakanya ukufumana izinto zokhuselo ezihambisa izinto ezinokuthi zihanjiswe kakuhle kwiizinto ezichanekileyo ngomxholo omncinci. Apha sibika i-graphene–silica (SiO x ) assembly, ebizwa ngokuba yi-graphene ball (GB), njengento yokugaleleka kwizinto zokuhlawula ezine-capacity ephezulu ezithanda i-nickel ezikunye ne-LIB anode material. Nganye i-GB iqulunqwe yiziko le-SiO x nanoparticle kunye nemiqolo ye-graphene ejikelezileyo, edala isakhiwo esinobukhulu obuthathu (3D) esinjenge-popcorn. Ii-SiO x nanoparticles zidlala indima ebalulekileyo kwiimicimbi ezininzi, njengokuphelisa ukubunjwa komqolo we-silicon carbide (SiC) kwi-SiO x –graphene interface ngexesha lokukhula kwe-graphene, ukuqinisekisa ukugaleleka okufanayo kwe-GB kwizinto zokuhlawula, kunye nokubonelela ngomthamo omkhulu xa i-GB isetyenziswa njengento yokuhlawula i-anode. Ukugaleleka okufanayo kwe-GB kwikhatodi elihamba phambili eligxile kwi-nickel kuphucula uzinzo lwe-interfacial kunye ne-electrolyte kunye nokuhanjiswa kombane kwi-electrode, ukuphucula ubomi bebhetri kunye nokukwazi ukutshaja ngokukhawuleza kwekhathodi kakhulu. Ukuthatha iingenelo ezizodwa ze-GB, i-full-cell equkethe ikhatodi egalelekileyo ye-GB kunye ne-anode ye-GB ibonisa ukwenzeka kobuninzi bamandla omthamo osondeleyo kwi-800 Wh L−1 kwimeko ye-cell yokuthengisa, kunye nokugcinwa komthamo ophezulu kwe-78.6% emva kwe-500 cycles kwi-5C kunye ne-60 °C. Iziphumo Ukufakwa kwe-graphene ball Ukufaka i-GB enjenge-popcorn, siphuhlise inkqubo ye-chemical vapor deposition (CVD) yokukhula kwe-graphene. Igasa le-CH4 langena efundini kwindawo ye-SiO2 nanoparticle enemibini ye-20–30 nm kwi-1000 °C. Kule mbasa, i-CH4 iyakwahlulwa ivelise ii-athomu zegesi yohydrogen, ezingabuyisela i-SiO2 ibe yi-SiO x (x < 2). I-OH− nayo iveliswa ngaxeshanye ngokusebenzisa le nxibelelwano ilandelayo: Umyalezo obalulekileyo kule nxibelelwano yile yokuba i-SiO x evelisiweyo ibonelela ngeendawo zokukhuthaza ukukhula kwe-graphene, kwaye i-OH− isebenza njenge-oxidant ethambileyo yokwenza kube lula ukubunjwa kwe-carbon engagqwalanga kwi-graphene , . Indima yee-oxidants ezithambileyo ekubunjweni kwe-carbon engagqwalanga ichazwe kutshanje  ngokuba, ngaphandle kwe-oxidant ethambileyo, ukubunjwa kwe-carbon engagqwalanga kuyalawula. Nangona kunjalo, xa kukho i-oxidant ethambileyo, kwafunyaniswa ukuba i-nxibelelwano ejolise ekubunjweni kwe-CO okanye i-CO2 ikhethwa kwi-athomu zekhonkco ezingeke zibe yi-carbon engagqwalanga. Ngokwenyani, ukukhula okubalulekileyo kwe-graphene kusetyenziswa iikhatalisti zemitha kuyaziwa ukuba kwenzeka ngendlela efanayo , , , apho i-oxygen eseleyo kwindawo yemitha ibangela ukhetho lwe-nxibelelwano ejolise ekubunjweni kwe-carbon engagqwalanga. Ubukho be-oxidant ethambileyo buthintele ukubunjwa komqolo we-silicon carbide (SiC) kumphezulu we-SiO x kuba i-oxidant ithintela ukuncitshiswa kwe-Si ukuba ibe yi-SiC formation . 14 15 16 17 18 19 19 Kwisikimu sethu senxibelelwano esekelwe ekusetyenzisweni okukodwa kwe-CH4, kwiimbasa ezingezantsi kwe-900 °C, i-graphene yayingakhuli kancinci. Ngokwahlukileyo, kwi-1050 °C nangaphezulu, ukukhula kwe-graphene kwaye kwaba yinto egqithiseleyo ejolise ekubunjweni kwe-graphite (Supplementary Fig. 1). Ngokukodwa, umbasa wokukhula we-1000 °C ungezantsi kunezo (1100–1400 °C) zidla zisetyenziselwa ukukhula kwe-graphene esekelwe kwi-CVD esekelwe kwi-Si kunye ne-SiO2 substrates ngaphandle kweekhatalisti zemitha , , . Indima ebalulekileyo yendawo yokukhula ichazwe ngovavanyo lolawulo (Supplementary Fig. 2); ngokulandela iinkqubo eziqhelekileyo ze-CVD ezisebenzisa iikhatalisti zemitha, i-CH4 kunye ne-H2 zangeniswa kwi-3:7 volumetric flow ratio kwi-1000 °C. Kuba ukwahlulwa kwe-CH4 kuye kwathintelwa bubungakanani obukhulu be-H2, ukukhula kwe-graphene kuye kwab pincinci kakhulu, kubonisa ukubaluleka kokusetyenziswa okukodwa kwe-CH4 ekukhuleni okusebenzayo kwe-graphene kwiprothokholi yethu yokufakwa. Ngokubanzi, ukhetho lwezinto ezisetyenziswayo kunye nombasa wokukhula kwisikimu senxibelelwano sangoku sijonge kude kwiindawo ezikhoyo ze-CVD ezisebenzisa iikhatalisti zemitha kwaye idlala indima ephambili ekwenzeni i-graphene–SiO x assembly enesakhiwo esinobukhulu obuthathu. 20 21 22 Uhlalutyo oluchungechunge lwe-scanning electron microscope (SEM) (Supplementary Fig. 3a–f) kunye ne-transmission electron microscope (TEM) (Fig. 1a–g) olwenziwa ngexesha lenkqubo ye-CVD lubonisa utshintsho ekukhuleni nasekuhambeni kwe-graphene. Emva kwemizuzu emi-5 yenkqubo ye-CVD, ifilimu ye-graphene ene-2–3 layer-thick ibonwe kancinci kumphezulu we-SiO2 (Fig. 1b, e), kunye nombala womgubo uguqukele ebomnyama (Supplementary Fig. 3g). Ukukhula kwe-graphene kube namandla ngakumbi emva kwemizuzu emi-30 yenkqubo ye-CVD, apho isakhiwo sephepha esinobukhulu obuthathu sibonakala ngokucacileyo (Fig. 1c, f). Umfanekiso we-TEM ophezulu (Fig. 1g) ubanda ulungelelwaniso lwe-athomu ye-hexagonal kwinxalenye ye-graphene, ebonisa iphepha layo eliphambili. Emva kwemizuzu emi-30, kwakubuye kwabonakala ukuba ubungakanani be-SiO2 nanoparticle bancipha ukusuka kwi-28.2 ukuya kwi-15.3 nm ngokomyinga (Supplementary Fig. 4). Oku kwenzeka kuba ukukhula kwe-graphene kubandakanya ukuncitshiswa kwe-SiO2 okubizwa ngentla kunye nokubunjwa kwe-OH−. Ngoko ke, ukukhula okupheleleyo kwe-graphene kufana kakhulu ne-popcorn enwebeka kwisimo esikhulu sobukhulu obuthathu, esenziwa ngexabiso leenkozo zokuqala (Fig. 1h).   Ukukhula kwe-Graphene kusuka kwi-SiO2 nanoparticles.  –  Uhlalutyo lwe-TEM   ngaphambi kokukhula kwe-CVD,   emva kwemizuzu emi-5 yokukhula, kunye   emva kwemizuzu emi-30 yokukhula (imilinganiselo yomgca, i-50 nm).  –  Imifanekiso yabo ephuculweyo ngokulandelelanayo (imilinganiselo yomgca, i-10 nm).   Umboniso ophezulu wokukhula kwe-graphene emva kwemizuzu emi-30 kunye nombono wayo onomgangatho we-athomu ukusuka ebhoneni elimhlophe (inset) (umlinganiselo womgca, i-2 nm).   Umzekeliso wobugcisa wokukhula kwe-graphene enjenge-popcorn ukusuka kwi-SiO2 nanoparticles a c a b c d f g h Ukhula lwe-graphene lwacaciswa ngakumbi ngohlalutyo olongezelelweyo. I-X-ray diffraction (XRD) imiqolo efunyenwe ngexesha lokukhula ibonisa ukuba njengoko inkqubo ye-CVD iqhubeka, imiqolo kwi-2θ = 26.44° kunye ne-44°, ehambelana neziphelo (002) kunye ne-(101) ze-graphite, yakhula ngokuqhubekayo (Fig. 2a), yakhuthaza kwakhona ukubunjwa kwe-carbon engagqwalanga , , . Ukukhula kwe-graphene kwakubonakala kwimiqolo kwi-284.5 kunye ne-291.5 eV kwi-C 1s branch ye-X-ray photoelectron spectroscopy (XPS) analysis (Fig. 2b) , . Umqolo kwi-284.5 eV ubekwe kwi-C–C kunye ne-C=C bonds, eya vela kakhulu emva kwemizuzu emi-30 yokukhula ngenxa yokubunjwa kwe-carbon engagqwalanga. Imiqolo ye-XPS eqhubekayo kwi-Si 1s branch ye-XPS analysis (Fig. 2c) iqinisekisa kwakhona  ukuncitshiswa kwe-SiO2 ngexesha lenkqubo ye-CVD. Ngokwanda komsebenzi wokukhula, umqolo osondele kwi-103 eV uhambile kumandla okubopha aphantsi ngenxa yokuncipha kwe-oxidation state ye-Si. Ngokusekelwe kubukho kunye nobuninzi bomsindo wekhonoko kwi-energy dispersive X-ray (EDX) mapping (Fig. 2d–g), kwafunyaniswa ukuba nangemva kwemizuzu emi-5, ukukhula kwe-graphene kwenzeka kumphezulu we-SiO x , kwaye emva kwemizuzu emi-30, ukukhula kuye kwafikelela kulo lonke ummandla womfanekiso, ngelixa i-Si kunye ne-O zahlala zihanjiswa ngokufanayo. Icandelo lesantya le-graphene, kunye neziphumo zohlalutyo lweRaman, umthamo womphezulu, kunye nokuhanjiswa kwe-GB kwi-CVD yexesha lokukhula elahlukileyo ziqulunqwe kwis Table 1. Ngokubhekisele kumthamo womphezulu, ukuncipha kwayo ngokwanda komsebenzi wokunxibelelana kubangelwa yi-graphitization eqhubekayo apho imiqolo ye-graphene idibene kwaye igqatshelwe. Uhlalutyo oluneenkcukacha lweRaman kunye ne-thermogravimetric (TG) iziphumo ziboniswa kwi-Supplementary Fig. 5. 23 24 25 22 23 25   Uhlalutyo lwe-graphene-ball ngexesha lokukhula kwayo.  –  Ukubeka iliso ekukhuleni kwe-graphene ngexesha lenkqubo ye-CVD kusetyenziswa   XRD,   XPS kwi-C 1s branch, kunye   XPS Si 2p branch.  –  I-EDX elemental mapping ngokubhekisele ku-C, O, kunye ne-Si emva kweminyaka emi-5 kunye neminyaka emi-30 yokukhula kwe-graphene ukusuka kwi-SiO2 (imilinganiselo yomgca, i-50 nm) a c a b c d g Ukugaleleka kwe-graphene ball kwikhatodi enomlinganiselo ophezulu we-Ni Ngenxa yembonakalo yayo enomqolo omnye, i-graphene iye yacinga ukuba yenye yezona zinto zifanelekileyo zokugaleleka kumphezulu kwezinto zokuhlawula ezihamba phambili. Nangona kunjalo, kwimeko yeendlela ezaziwayo zokuxuba , , ,  esekelwe kwindlela kaHummer, ukufezekisa ukugaleleka okufanayo kunye nomxholo olinganiselweyo we-graphene akulula ngenxa ye-agglomeration, evela ekunxibelelaneni okunamandla kwe-electrostatic phakathi kwemiphezulu ye-graphene. Ngomzamo wokoyisa ingxaki ye-agglomeration, indlela eyahlukileyo, njengokugxobhoza kwe-graphite kusetyenziswa inkqubo ye-ball-milling, sele ingene . Nangona kunjalo, le nkqubo idla ngokuba yindawo (ngaphezu kwe-6h) kwaye, okubaluleke kakhulu, ingalimaza ubuchule be-crystal bezinto ezibambeleyo. Kufuneka kuphunqiswe nokuba ukugaleleka kwe-carbon engagqwalanga ngeenkqubo ze-CVD akufanelekanga kwizinto ze-oxide ezinomlinganiselo ophezulu we-Ni ,   kuba iinkqubo ze-CVD zikhuphela iintsimbi ezidlulayo (TMs), ziphazamisa isakhiwo se-crystal sokuqala sezinto ezibambeleyo. 26 27 28 29 30 31 32 Ngokwahlukileyo, i-GB efakiweyo kulo sifundo ingagaleleka kumphezulu womgubo we-LiNi0.6Co0.1Mn0.3O2 wokuthengisa (ubungakanani = ~10 µm) ngomxholo omncinci we-1 wt% nge-Nobilta milling process ethambileyo. Inkqubo yokugaleleka ikwangonxibelelana ngokukhawuleza (~10 min kwi-3000 rpm). Ii-seeds ze-SiO x zidala indima ebalulekileyo ekuvumela ukuba le mgaleleko ifane kwiimxholo ezincinci zesisantya. Ii-seeds ze-SiO x ziqulathe i-57.5 wt% ye-GB (isiphumo se-TG kwi-Supplementary Fig. 5b) kwaye kwinkqubo yokugaleleka, ubukho bazo buvumela i-GB ukuba ibeke uxinzelelo lokutsala kumphezulu we-LiNi0.6Co0.1Mn0.3O2, idala unxibelelwano oluchanekileyo kunye nokungena. Ukucacisa le ntshukumo, inkqubo yokugaleleka efanayo yenziwa nomxube omphysical we-0.5 wt% SiO2 kunye ne-0.5 wt% graphene. Lo mxube ubone ukulimala kwe-crystal kwindawo engaphakathi ye-NCM ngenxa yokungqubana okunamandla phakathi kweziqhekeza ze-LiNi0.6Co0.1Mn0.3O2 kunye nokungqubana phakathi kweziqhekeza ze-LiNi0.6Co0.1Mn0.3O2 kunye nodonga lwesitya (Supplementary Fig. 6). Ezi ntshukumo zanda yi-graphene agglomeration eyenzeka xa kungabikho izakhiwo ezihambelanayo ezine-SiO x nanoparticle centres. Ukugaleleka okufanayo kwe-GB kwacaciswa ngoohlalutyo lwe-SEM kunye ne-TEM. Ukusukela ngoku, i-LiNi0.6Co0.1Mn0.3O2 ngaphambi nangemva kokugaleleka kwe-GB ibizwa ngokuba yi-pristine NCM kunye ne-GB-NCM, ngokulandelanayo. Imifanekiso ye-SEM encinci yokukhula kwe-NCM ngaphambi nangemva kokugaleleka kwe-GB (Fig. 3a, b, Supplementary Fig. 6a, b) yabonisa iimfonomo ezifanayo kakhulu ngenxa yokuhanjiswa okufanayo komxholo ophantsi we-GB. Nangona kunjalo, umboniso we-SEM ophezulu we-GB-NCM ubonisa ukuba i-GB ingenelele kumawonga phakathi kweziqhekeza zangaphakathi ze-NCM (Fig. 3d). Ukungena kwe-GB kwaboniswa ngokucacileyo kwimifanekiso ye-TEM (Fig. 3e, f). KwiFig. 3e, iphepha le-graphene labonakala kwindawo evulekileyo ngaphezu kweqhekeza le-NCM (bona imigca ebomvu echaziweyo). Eminye imiphezulu ye-graphene yalandelelana kumphezulu we-NCM kwaye yabonisa umgama ofanayo ongaphakathi we-3.3 ok

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Ukutshaja Okukhawulezayo, Ubomi Obude: Ubuchwepheshe beGraphene obuhlaziya iiBatri zeLithium

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