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Kumabhethri e-lithium-ion, ukuze kuzuzwe umgomo ongu-350 Wh Kg-1, i-cathode material isebenzisa i-nickel-rich layered oxide (LiNixMnyCozO2, x+y+z=1, ebizwa nge-NMCxyz). Ngokukhula kokuminyana kwamandla, izingozi ezihlobene nokubaleka okushisayo kwama-LIB kudonse ukunaka kwabantu. Ngokombono wezinto ezibonakalayo, ama-electrode ane-nickel positive anezinkinga ezinkulu zokuphepha. Ngaphezu kwalokho, i-oxidation/crosstalk yezinye izingxenye zebhethri, ezifana noketshezi oluphilayo nama-electrode angalungile, kungase futhi kubangele ukubaleka okushisayo, okubhekwa njengembangela ehamba phambili yezinkinga zokuphepha. Ukwakheka okulawulekayo kwe-in-situ kwesixhumi esibonakalayo se-electrolyte esizinzile kuyisu eliyinhloko lesizukulwane esilandelayo samabhethri e-lithium asekelwe kumandla aphezulu. Ngokukhethekile, i-solid and dense cathode-electrolyte interphase (CEI) enezingxenye ze-inorganic eziqinile eziphakeme zingaxazulula inkinga yokuphepha ngokuvimbela ukukhululwa komoyampilo. Kuze kube manje, kukhona ukushoda kocwaningo mayelana nezinto eziguqulwe i-cathode ze-CEI kanye nokuphepha kwezinga lebhethri.
Muva nje, u-Feng Xuning, u-Wang Li, no-Ouyang Minggao baseNyuvesi yaseTsinghua bashicilele iphepha locwaningo elinesihloko esithi "In-Built Ultraconformal Interphases Enable High-Safety Practical Practical Lithium Batteries" Ezimpahleni Zokugcina Amandla. Umbhali uhlole ukusebenza kokuphepha kwebhethri eligcwele elithambile le-NMC811/Gr kanye nokuzinza kokushisa kwe-electrode ehambisanayo ye-CEI. Indlela yokucindezelwa kwe-thermal runnaway phakathi kwe-material nebhethri ye-soft pack icutshungulwe ngokuphelele. Kusetshenziswa i-electrolyte ene-perfluorinated engashi, ibhethri eligcwele lohlobo lwesikhwama se-NMC811/Gr lalungiselelwa. Ukuzinza okushisayo kwe-NMC811 kwathuthukiswa ungqimba oluvikelayo lwe-CEI olunothe nge-inorganic LiF. I-CEI ye-LiF ingadambisa ngempumelelo ukukhululwa komoyampilo okubangelwa ukushintsha kwesigaba futhi ivimbele ukusabela kwe-exothermic phakathi kwe-NMC811 ejabulile kanye ne-electrolyte eyi-fluorinated.
Umfanekiso 1 Ukuqhathaniswa kwezimpawu zokubaleka ezishisayo zebhethri eligcwele lohlobo lwe-NMC811/Gr lwesikhwama lisebenzisa i-electrolyte ene-perfluorinated kanye ne-electrolyte evamile. Ngemva komjikelezo owodwa wamabhethri agcwele esikhwama se-electrolyte (a) EC/EMC kanye (b) ne-perfluorinated FEC/FEMC/HFE electrolyte. (c) I-electrolysis evamile ye-EC/EMC kanye (d) nebhethri egcwele isikhwama se-electrolyte ye-FEC/FEMC/HFE efakwe i-electrolyte emdala ngemva kwemijikelezo engu-100.
Ngebhethri le-NMC811/Gr eline-electrolyte evamile ngemva komjikelezo owodwa (Umfanekiso 1a), i-T2 iku-202.5°C. I-T2 yenzeka lapho i-voltage ye-open-circuit yehla. Nokho, i-T2 yebhethri esebenzisa i-electrolyte ene-perfluorinated ifinyelela ku-220.2°C (Umfanekiso 1b), okubonisa ukuthi i-electrolyte ene-perfluorinated ingathuthukisa ukuphepha okungokwemvelo kokushisa kwebhethri ngezinga elithile ngenxa yokuqina kwayo okushisayo okuphakeme. Njengoba ibhethri likhula, inani le-T2 lebhethri le-electrolyte evamile lehla laya ku-195.2 °C (Umfanekiso 1c). Nokho, inqubo yokuguga ayithinti i-T2 yebhethri isebenzisa i-electrolyte ene-perfluorinated (Umfanekiso 1d). Ukwengeza, inani eliphakeme le-dT/dt lebhethri elisebenzisa i-electrolyte evamile phakathi ne-TR liphezulu njengo-113°C s-1, kuyilapho ibhethri elisebenzisa i-electrolyte ene-perfluorinated lingu-32°C s-1 kuphela. Umehluko ku-T2 yamabhethri aguga ungabalelwa ekuzinzeni okungokwemvelo kokushisa kwe-NMC811 ejabulile, encishiswa ngaphansi kwama-electrolyte avamile, kodwa angagcinwa ngempumelelo ngaphansi kwama-electrolyte ane-perfluorinated.
Umfanekiso 2 Ukuzinza okushisayo kwe-delithiation ye-NMC811 i-electrode ephozithivu kanye nengxube yebhethri ye-NMC811/Gr. (A,b) Amamephu we-Contour we-C-NMC811 kanye ne-F-NMC811 synchrotron high-energy XRD kanye nezinguquko ezihambisanayo (003) zokuhluka kwe-diffraction. (c) Ukuziphatha kokushisisa nokukhishwa komoyampilo kwe-electrode ephozithivu ye-C-NMC811 ne-F-NMC811. (d) Ijika le-DSC lengxube yesampula ye-electrode ejabulisayo, i-electrode eyi-lithiated negative, ne-electrolyte.
Izibalo 2a kanye no-b zibonisa amajika e-HEXRD e-NMC81 ejabulile enezendlalelo ze-CEI ezihlukene lapho kukhona ama-electrolyte avamile kanye naphakathi nenkathi esukela kuzinga lokushisa legumbi ukuya ku-600°C. Imiphumela ibonisa ngokucacile ukuthi lapho kukhona i-electrolyte, ungqimba oluqinile lwe-CEI luhambisana nokuzinza kokushisa kwe-lithium-deposited cathode. Njengoba kuboniswe kuMfanekiso 2c, i-F-NMC811 eyodwa ibonise ukuphakama okuhamba kancane kwe-exothermic ku-233.8°C, kanti i-C-NMC811 exothermic yavela ku-227.3°C. Ngaphezu kwalokho, ukushuba nezinga lokukhishwa komoyampilo okubangelwa ukushintshwa kwesigaba se-C-NMC811 kubi kakhulu kunalezo ze-F-NMC811, futhi kuqinisekisa ukuthi i-CEI eqinile ithuthukisa ukuzinza okungokwemvelo kwe-F-NMC811. Umfanekiso 2d wenza ukuhlolwa kwe-DSC kwingxube ye-NMC811 ejabulile nezinye izingxenye zebhethri ezihambisanayo. Kuma-electrolyte avamile, iziqongo ze-exothermic zamasampuli ezinomjikelezo ongu-1 no-100 zibonisa ukuthi ukuguga kwesixhumi esibonakalayo esivamile kuzonciphisa ukuzinza okushisayo. Ngokuphambene, ku-electrolyte ene-perfluorinated, imidwebo ngemva komjikelezo ongu-1 no-100 ibonisa iziqongo ze-exothermic ezibanzi nezithambile, ngokuhambisana nezinga lokushisa le-TR trigger (T2). Imiphumela (Umfanekiso 1) iyahambisana, okubonisa ukuthi i-CEI eqinile ingathuthukisa ngempumelelo ukuzinza kokushisa kwe-NMC811 asebekhulile nabajabulile nezinye izingxenye zebhethri.
Umfanekiso wesi-3 Ukwenziwa kwe-electrode ejabulile ye-NMC811 ku-electrolyte ene-perfluorinated. (ab) Izithombe ze-SEM ezihlukene ze-F-NMC811 endala ye-electrode kanye nemephu ye-EDS ehambisanayo. (ch) Ukusatshalaliswa kwe-elementi. (ij) Isithombe se-SEM esihlukanisayo se-F-NMC811 endala ye-electrode ku-xy ebonakalayo. (km) Ukwakhiwa kabusha kwesakhiwo se-3D FIB-SEM nokusabalalisa kwendawo kwama-elementi F.
Ukuqinisekisa ukwakheka okulawulekayo kwe-Fluorinated CEI, i-morphology ye-cross-sectional kanye nokusatshalaliswa kwesici se-electrode ephozithivu ye-NMC811 endala etholwe kubhethri le-soft-pack yangempela ibonakala nge-FIB-SEM (Umfanekiso 3 ah). Ku-electrolyte ene-perfluorinated, kwakheka ungqimba lwe-CEI olufana ne-fluorinated ebusweni be-F-NMC811. Ngokuphambene, i-C-NMC811 ku-electrolyte evamile ayinayo u-F futhi yakha ungqimba lwe-CEI olungalingani. Okuqukethwe kwesici sika-F esigabeni esiphambanayo se-F-NMC811 (Umfanekiso 3h) kungaphezulu kwalokho kwe-C-NMC811, okufakazela futhi ukuthi ukwakheka kwe-in-situ kwe-mesophase e-inorganic fluorinated kuyisihluthulelo sokugcina ukuzinza kwe-NMC811 ejabulile. . Ngosizo lwe-FIB-SEM kanye nemephu ye-EDS, njengoba kukhonjisiwe kuMfanekiso 3m, ibone izici eziningi zika-F kumodeli ye-3D ebusweni be-F-NMC811.
Umfanekiso 4a) Ukusabalalisa ukujula kwe-elementi ebusweni be-electrode ephozithivu ye-NMC811 ejabulile. (ac) I-FIB-TOF-SIMS iphazamisa ukusatshalaliswa kwezinto ezingu-F, O, kanye ne-Li ku-electrode ephozithivu ye-NMC811. (df) Ukwakheka komhlaba nokusatshalaliswa okujulile kwe-elementi F, O, kanye ne-Li ye-NMC811.
I-FIB-TOF-SEM iphinde yembula ukujula kokusabalalisa kwezakhi endaweni ye-electrode ephozithivu ye-NMC811 (Umfanekiso 4). Uma kuqhathaniswa namasampula oqobo kanye ne-C-NMC811, ukwanda okuphawulekayo kusiginali ka-F kutholwe kungqimba olungaphezulu lwe-F-NMC811 (Umfanekiso 4a). Ngaphezu kwalokho, izimpawu ze-O ezibuthakathaka neziphezulu ze-Li ebusweni zibonisa ukwakheka kwezingqimba ze-F- ne-Li-rich CEI (Umfanekiso 4b, c). Le miphumela yonke iqinisekise ukuthi i-F-NMC811 inongqimba lwe-LiF-rich CEI. Uma kuqhathaniswa ne-CEI ye-C-NMC811, isendlalelo se-CEI se-F-NMC811 siqukethe ama-elementi amaningi ka-F kanye ne-Li. Ngaphezu kwalokho, njengoba kuboniswe ku-FIGS. 4d-f, ngokombono wokujula kwe-ion etching, isakhiwo se-NMC811 yasekuqaleni siqine kakhulu kunaleso se-NMC811 ejabulile. Ukujula kwe-Etch ye-F-NMC811 endala kuncane kune-C-NMC811, okusho ukuthi i-F-NMC811 inokusimama okuhle kakhulu kwesakhiwo.
Umfanekiso 5 CEI ukwakheka kwamakhemikhali endaweni engaphezulu ye-electrode ephozithivu ye-NMC811. (a) I-XPS spectrum ye-NMC811 ye-electrode ephozithivu ye-CEI. (bc) I-XPS C1s kanye ne-F1s spectra ye-NMC811 yoqobo ye-electrode CEI ejabulisayo. (d) I-Cryo-transmission electron microscope: ukusatshalaliswa kwesici se-F-NMC811. (e) Isithombe se-TEM esiqandisiwe se-CEI esakhiwe ku-F-NMC81. (fg) Izithombe ze-STEM-HAADF kanye ne-STEM-ABF ze-C-NMC811. (hi) Izithombe ze-STEM-HAADF kanye ne-STEM-ABF ze-F-NMC811.
Basebenzise i-XPS ukukhombisa ukwakheka kwamakhemikhali kwe-CEI ku-NMC811 (Umfanekiso 5). Ngokungafani ne-C-NMC811 yasekuqaleni, i-CEI ye-F-NMC811 iqukethe u-F no-Li omkhulu kodwa omncane u-C (Umfanekiso 5a). Ukuncishiswa kwezinhlobo ze-C kukhombisa ukuthi i-LiF-rich rich CEI ingavikela i-F-NMC811 ngokunciphisa ukusabela okuseceleni okuqhubekayo ngama-electrolyte (Umfanekiso 5b). Ngaphezu kwalokho, amanani amancane we-CO ne-C=O abonisa ukuthi i-solvolysis ye-F-NMC811 ikhawulelwe. Ku-spectrum ye-F1s ye-XPS (Umfanekiso 5c), i-F-NMC811 ibonise isignali ye-LiF enamandla, eqinisekisa ukuthi i-CEI iqukethe inani elikhulu le-LiF elitholakala kuzincibilikisi ezine-fluorinated. Ukudwetshwa kwezakhi ze-F, O, Ni, Co, kanye ne-Mn endaweni yasendaweni ezinhlayiyeni ze-F-NMC811 kubonisa ukuthi imininingwane isatshalaliswa ngokufanayo iyonke (Umfanekiso 5d). Isithombe se-TEM enezinga lokushisa eliphansi kuMfanekiso 5e sibonisa ukuthi i-CEI ingasebenza njengesendlalelo esivikelayo ukuze imboze ngokufanayo i-electrode ephozithivu ye-NMC811. Ukuze kuqhutshekwe kuqinisekiswe ukuvela kwesakhiwo se-interface, ukuhlolwa kwe-electron microscopy eyindilinga ene-engeli ephezulu eyindilinga eyindilinga emnyama (HAADF-STEM kanye ne-circular bright-field scanning transmission electron microscopy) (ABF-STEM) kwenziwa. -NMC811), Ingaphezulu le-electrode ejikelezayo ephozithivu lishintshe kakhulu esigabeni, futhi isigaba sikasawoti we-rock ophazamisekile sinqwabelana phezu kwe-electrode ephozithivu (Umfanekiso 5f) Nge-electrolyte ene-perfluorinated, ingaphezulu le-F-NMC811 I-electrode eyakhayo igcina isakhiwo esinezingqimba (Umfanekiso 5h), ikhombisa ingozi Isigaba sicindezelwa ngempumelelo Ngaphezu kwalokho, ungqimba lwe-CEI olufaniswayo lwabonwa ebusweni be-F-NMC811 (Umfanekiso 5i-g) Le miphumela iqhubeka ifakazela ukufana kwe Isendlalelo se-CEI endaweni ephozithivu ye-electrode ye-NMC811 ku-electrolyte ene-perfluorinated.
Umfanekiso 6a) Ububanzi be-TOF-SIMS besigaba se-interphase ebusweni be-electrode ephozithivu ye-NMC811. (ac) Ukuhlaziywa okujulile kwezingcezu ze-ion yesibili ku-electrode ephozithivu ye-NMC811. (df) I-TOF-SIMS i-spectrum yamakhemikhali yocezu lwe-ion lwesibili ngemva kwemizuzwana engu-180 yokufafaza kweyokuqala, i-C-NMC811 ne-F-NMC811.
Izingcezu ze-C2F ngokuvamile zibhekwa njengezinto eziphilayo ze-CEI, kanti izingcezu ze-LiF2- kanye ne-PO2 zivame ukuthathwa njengezinhlobo ze-inorganic. Izimpawu ezithuthukiswe ngokuphawulekayo ze-LiF2- ne-PO2- zitholwe ekuhlolweni (Umfanekiso 6a, b), okubonisa ukuthi ungqimba lwe-CEI lwe-F-NMC811 luqukethe inani elikhulu lezinhlobo ze-inorganic. Ngokuphambene, i-C2F-signal ye-F-NMC811 ibuthakathaka kunaleyo ye-C-NMC811 (Figure 6c), okusho ukuthi ungqimba lwe-CEI lwe-F-NMC811 luqukethe izinhlobo zezinto eziphilayo ezibuthakathaka kancane. Olunye ucwaningo luthole (Umfanekiso 6d-f) ukuthi kunezinhlobo eziningi zezinhlobo ze-inorganic ku-CEI ye-F-NMC811, kuyilapho kunezinhlobo ezimbalwa ze-inorganic ku-C-NMC811. Yonke le miphumela ikhombisa ukwakheka kongqimba lwe-CEI oluqinile lwe-inorganic-rich ku-electrolyte ene-perfluorinated. Uma kuqhathaniswa nebhethri le-softpack ye-NMC811/Gr lisebenzisa i-electrolyte evamile, ukuthuthukiswa kokuphepha kwebhethri le-soft-pack kusetshenziswa i-electrolyte ene-perfluorinated kungase kubangelwe: Okokuqala, ukwakheka kwe-in-situ kongqimba lwe-CEI olucebile lwe-inorganic inorganic LiF kunenzuzo. Ukuzinza okungokwemvelo kokushisa kwe-electrode ejabulisayo ye-NMC811 kunciphisa ukukhululwa komoyampilo we-lattice okubangelwa ukuguquka kwesigaba; okwesibili, ungqimba oluqinile lwe-CEI oluvikelayo lwe-inorganic luphinde luvimbele i-delithiation esebenza kakhulu i-NMC811 ukuthi ingathintani ne-electrolyte, inciphisa ukusabela ohlangothini olushisayo; okwesithathu, I electrolyte perfluorinated has high ukuzinza ezishisayo emazingeni okushisa aphezulu.
Lo msebenzi ubike ukuthuthukiswa kwebhethri eligcwele lohlobo lwesikhwama se-Gr/NMC811 lisebenzisa i-electrolyte ene-perfluorinated, okuthuthukise kakhulu ukusebenza kwalo kokuphepha. Ukuzinza kwe-thermal kwangaphakathi. Ucwaningo olunzulu lwendlela ye-TR inhibition kanye nokuhlobana phakathi kwezinto namaleveli ebhethri. Inqubo yokuguga ayilithinti izinga lokushisa le-TR trigger (T2) yebhethri ye-electrolyte ene-perfluorinated phakathi naso sonke isiphepho, enezinzuzo ezisobala ngaphezu kwebhethri eliguga kusetshenziswa i-electrolyte evamile. Ngaphezu kwalokho, ukuphakama kwe-exothermic kuhambisana nemiphumela ye-TR, okubonisa ukuthi i-CEI eqinile ihambisana nokuzinza okushisayo kwe-electrode e-lithium-free positive kanye nezinye izingxenye zebhethri. Le miphumela ibonisa ukuthi idizayini yokulawula e-in-situ yongqimba oluzinzile lwe-CEI inokubaluleka kokuqondisa okubalulekile ekusetshenzisweni okungokoqobo kwamabhethri e-lithium anamandla aphephile.
I-Ultraconformal Interphases Eyakhelwe Ngaphakathi Inika Amandla Amabhethri E-Lithium Asebenza Ngokuvikeleka Okuphezulu, Izinto Zokugcina Amandla, 2021.
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