ESM: Hoʻokomo ʻia i loko o ka ultra-conformal interface o perfluorinated electrolyte no nā ʻenekini lithium ikaika kiʻekiʻe.

Kahua ʻImi

I loko o nā pākahi lithium-ion, e hoʻokō i ka pahuhopu o 350 Wh Kg-1, hoʻohana ka mea cathode i ka nickel-rich layered oxide (LiNixMnyCozO2, x+y+z=1, i kapa ʻia ʻo NMCxyz). Me ka piʻi ʻana o ka ikaika o ka ikehu, ʻo nā pōʻino e pili ana i ka holo ʻana o ka wela o nā LIB ua hoʻohuli i ka manaʻo o ka poʻe. Mai kahi hiʻohiʻona waiwai, loaʻa i nā electrodes maikaʻi ka waiwai nickel i nā pilikia palekana. Eia kekahi, hiki i ka oxidation/crosstalk o nā mea pākaukau ʻē aʻe, e like me nā wai organik a me nā electrodes maikaʻi ʻole, hiki ke hoʻoulu i ka holo ʻana i ka wela, i manaʻo ʻia ke kumu nui o nā pilikia palekana. ʻO ka hoʻokumu ʻana i loko o kahi kikowaena electrode-electrolyte paʻa ka hoʻolālā mua no ka hanauna e hiki mai ana o nā pākahi lithium-density kiʻekiʻe. ʻO kahi kikoʻī, hiki i kahi cathode-electrolyte interphase (CEI) paʻa a paʻa me nā ʻāpana inorganic ʻoi aʻe ka thermal stability hiki ke hoʻonā i ka pilikia palekana ma ke kāohi ʻana i ka hoʻokuʻu ʻana o ka oxygen. I kēia manawa, nele ka noiʻi ʻana i nā mea i hoʻololi ʻia e ka cathode CEI a me ka palekana pae pākaukau.

Hōʻike hoʻokō

I kēia mau lā, ua paʻi ʻo Feng Xuning, Wang Li, a me Ouyang Minggao o ke Kulanui ʻo Tsinghua i kahi pepa noiʻi i kapa ʻia ʻo "In-Built Ultraconformal Interphases Enable High-Safety Practical Lithium Batteries" ma ka Energy Storage Materials. Ua loiloi ka mea kākau i ka hana palekana o ka pākaukau NMC811/Gr i hoʻopaʻa ʻia i ka palupalu a me ke kūpaʻa wela o ka electrode kūpono CEI. Ua aʻo piha ʻia ke ʻano hana hoʻopau ʻana i ka wela ma waena o ka mea a me ka puʻupuʻu palupalu. Ma ka hoʻohana ʻana i ka electrolyte perfluorinated non-flammable, ua hoʻomākaukau ʻia kahi pahu pahu piha ʻano NMC811/Gr. Ua hoʻomaikaʻi ʻia ke kūpaʻa wela o NMC811 e ka papa pale CEI i hoʻokumu ʻia i loko o ka wahi i waiwai i ka LiF inorganic. Hiki i ka CEI o LiF ke hoʻohaʻahaʻa maikaʻi i ka hoʻokuʻu ʻana o ka oxygen ma muli o ka hoʻololi ʻana o ka pae a keʻakeʻa i ka hopena exothermic ma waena o ka NMC811 hauʻoli a me ka fluorinated electrolyte.

alakaʻi kiʻi

Kiʻi 1 Ka hoʻohālikelike ʻana i nā hiʻohiʻona holo wela o ka NMC811/Gr pouch-type piha pākahi me ka hoʻohana ʻana i ka electrolyte perfluorinated a me ka electrolyte maʻamau. Ma hope o hoʻokahi pōʻaiapuni o ka kuʻuna (a) EC/EMC a me (b) perfluorinated FEC/FEMC/HFE electrolyte pouch ʻano pahu piha. (c) EC/EMC electrolysis maʻamau a me (d) perfluorinated FEC/FEMC/HFE electrolyte pouch-type piha pākaukau ma hope o 100 pōʻai.

No ka pila NMC811/Gr me ka electrolyte kuʻuna ma hope o hoʻokahi pōʻai (Figure 1a), aia ʻo T2 ma 202.5°C. Hana ʻia ʻo T2 i ka wā e hāʻule ai ka uila kaapuni hāmama. Eia naʻe, hiki i ka T2 o ka pākaukau e hoʻohana ana i ka electrolyte perfluorinated a hiki i 220.2 ° C (Figure 1b), e hōʻike ana e hiki i ka electrolyte perfluorinated ke hoʻomaikaʻi i ka palekana thermal inherent o ka pā i kekahi ʻano ma muli o kona kūpaʻa wela kiʻekiʻe. E like me nā makahiki o ka pākaukau, hāʻule ka waiwai T2 o ka pā uila electrolyte maʻamau i 195.2 °C (Figure 1c). Eia naʻe, ʻaʻole pili ke kaʻina hana ʻelemakule i ka T2 o ka pākaukau me ka hoʻohana ʻana i nā electrolytes perfluorinated (Figure 1d). Eia kekahi, ʻo ka nui o ka dT/dt waiwai o ka pākaukau e hoʻohana ana i ka electrolyte kuʻuna i ka wā TR he kiʻekiʻe e like me 113°C s-1, aʻo ka pākaukau e hoʻohana ana i ka electrolyte perfluorinated he 32°C s-1 wale nō. Hiki ke hoʻohālikelike ʻia ka ʻokoʻa o ka T2 o nā ʻenekini kahiko i ke kūpaʻa wela o ka NMC811 hauʻoli, i hoʻemi ʻia ma lalo o nā electrolytes maʻamau, akā hiki ke mālama pono ʻia ma lalo o nā electrolytes perfluorinated.

Kiʻi 2 Thermal paʻa o delithiation NMC811 maikaʻi electrode a me NMC811/Gr hui puolo. (A,b) Nā palapala 'āina Contour o C-NMC811 a me F-NMC811 synchrotron high-energy XRD a me nā hoʻololi kiʻekiʻe o ka diffraction (003). (c) ʻO ka hana mehana a me ka hoʻokuʻu oxygen o ka electrode maikaʻi o C-NMC811 a me F-NMC811. (d) Pihi DSC o ka laʻana hui ʻana o ka electrode maikaʻi ʻoliʻoli, lithiated negative electrode, a me electrolyte.

Hōʻike nā kiʻi 2a a me b i nā pihi HEXRD o ka NMC81 hauʻoli me nā papa CEI like ʻole i ke alo o nā electrolytes maʻamau a i ka wā mai ka lumi wela a 600 ° C. Hōʻike maopopo nā hualoaʻa i ke alo o kahi electrolyte, kahi papa CEI ikaika e kūpono i ka paʻa wela o ka cathode i waiho ʻia i ka lithium. E like me ka mea i hōʻike ʻia ma ka Figure 2c, ua hōʻike ʻia kahi F-NMC811 hoʻokahi i kahi kiʻekiʻe exothermic lohi ma 233.8°C, aʻo ka C-NMC811 exothermic peak i ʻike ʻia ma 227.3°C. Eia kekahi, ʻoi aku ka koʻikoʻi o ka ikaika a me ka wikiwiki o ka hoʻokuʻu ʻana o ka oxygen ma muli o ka hoʻololi ʻana o ka māhele o C-NMC811 ma mua o ka F-NMC811, e hōʻoia hou ana e hoʻomaikaʻi ka CEI ikaika i ka paʻa wela o F-NMC811. Hana ʻo Figure 2d i kahi hoʻāʻo DSC ma kahi hui ʻana o ka NMC811 hauʻoli a me nā ʻāpana pākahi like ʻole. No nā electrolytes maʻamau, ʻo nā kiʻekiʻe exothermic o nā laʻana me nā pōʻai 1 a me 100 e hōʻike ana i ka ʻelemakule o ka interface kuʻuna e hōʻemi i ka paʻa wela. ʻO ka hoʻohālikelike, no ka electrolyte perfluorinated, hōʻike nā kiʻi ma hope o 1 a me 100 cycles i nā piko exothermic ākea a mālie, e like me ka TR trigger temperature (T2). Kūlike nā hopena (Figure 1), e hōʻike ana e hiki i ka CEI ikaika ke hoʻomaikaʻi maikaʻi i ka paʻa wela o ka NMC811 ʻelemakule a hauʻoli a me nā mea ʻē aʻe.

Kiʻi 3 ʻO ke ʻano o ka hauʻoli NMC811 electrode maikaʻi i ka electrolyte perfluorinated. (ab) Nā kiʻi SEM cross-sectional o ka F-NMC811 electrode maikaʻi a me ka palapala palapala EDS pili. (ch) Māhele māhele. (ij) Ke kiʻi SEM cross-sectional o ka elemakule F-NMC811 electrode maikaʻi ma ka xy virtual. (km) Ka hana hou ʻana o ka hoʻolālā 3D FIB-SEM a me ka hoʻokaʻawale ʻana o nā mea F.

No ka hōʻoia ʻana i ka hoʻokumu ʻia ʻana o ka CEI fluorinated, ua hōʻike ʻia ka morphology cross-sectional a me ka māhele ʻana o ka electrode maikaʻi NMC811 kahiko i hoʻihoʻi ʻia i loko o ka pahu pahu palupalu maoli e FIB-SEM (Figure 3 ah). I loko o ka electrolyte perfluorinated, ua ho'okumu 'ia kahi papa CEI fluorinated like 'ole ma ka ili o F-NMC811. ʻO ka mea ʻē aʻe, C-NMC811 i ka electrolyte maʻamau ʻaʻole F a hana i kahi papa CEI ʻole. ʻOi aku ka kiʻekiʻe o ka maʻiʻo F element ma ka ʻāpana keʻa o F-NMC811 (Figure 3h) ma mua o ka C-NMC811, kahi e hōʻoia hou ai i ka hoʻokumu ʻana o ka mesophase fluorinated inorganic ke kī i ka mālama ʻana i ka paʻa o ka NMC811 hauʻoli. . Me ke kōkua o ka palapala palapala FIB-SEM a me EDS, e like me ka mea i hōʻike ʻia ma ke Kiʻi 3m, ua ʻike ʻo ia i nā mea F he nui i ke kumu hoʻohālike 3D ma ka ʻili o F-NMC811.

Kiʻi 4a) Māhele hohonu ʻeleʻele ma ka ʻili o ka electrode maikaʻi NMC811 kumu a hauʻoli. (ac) FIB-TOF-SIMS e sputtering i ka puunaue ana o F, O, a me Li i loko o ka pono electrode o NMC811. (df) Ka morphology ili a me ka mahele hohonu o F, O, a me Li o NMC811.

Ua hōʻike hou aku ʻo FIB-TOF-SEM i ka māhele hohonu o nā mea ma ka ʻili o ka electrode maikaʻi o NMC811 (Figure 4). Hoʻohālikelike ʻia me nā kumu kumu a me C-NMC811 laʻana, ua ʻike ʻia kahi piʻi nui o ka hōʻailona F ma ka papa luna o luna o F-NMC811 (Figure 4a). Eia kekahi, ʻo nā hōʻailona nāwaliwali O a me Li kiʻekiʻe ma ka ʻili e hōʻike ana i ka hoʻokumu ʻana o nā ʻāpana F- a me Li-rich CEI (Figure 4b, c). Ua hōʻoia kēia mau hopena i loaʻa iā F-NMC811 kahi ʻāpana CEI waiwai LiF. Ke hoʻohālikelike ʻia me ka CEI o C-NMC811, ʻo ka papa CEI o F-NMC811 ka nui o nā mea F a me Li. Eia hou, e like me ka mea i hōʻike ʻia ma FIGS. 4d-f, mai ka manaʻo o ka ion etching hohonu, ʻoi aku ka ikaika o ke ʻano o ka NMC811 kumu ma mua o ka NMC811 hauʻoli. ʻOi aku ka liʻiliʻi o ka hohonu etch o F-NMC811 kahiko ma mua o C-NMC811, ʻo ia hoʻi, ʻo F-NMC811 ka paʻa paʻa.

Kiʻi 5 CEI hoʻohui kemika ma ka ʻili o ka electrode maikaʻi o NMC811. (a) XPS spectrum o NMC811 maikaʻi electrode CEI. (bc) XPS C1s a me F1s spectra o ke kumu a me ka hauʻoli NMC811 electrode CEI maikaʻi. (d) Cryo-transmission electron microscope: māhele māhele o F-NMC811. (e) Kiʻi TEM paʻa o CEI i hoʻokumu ʻia ma F-NMC81. (fg) STEM-HAADF a me STEM-ABF kiʻi o C-NMC811. (hi) STEM-HAADF a me STEM-ABF kiʻi o F-NMC811.

Ua hoʻohana lākou i ka XPS e hōʻike i ke ʻano kemika o CEI ma NMC811 (Figure 5). ʻAʻole like me ka C-NMC811 mua, aia i ka CEI o F-NMC811 kahi F nui a me Li akā he C liʻiliʻi (Figure 5a). ʻO ka hōʻemi ʻana o nā ʻano C e hōʻike ana e hiki i ka CEI waiwai nui o LiF ke pale iā F-NMC811 ma ka hōʻemi ʻana i nā hopena ʻaoʻao i hoʻomau ʻia me nā electrolytes (Figure 5b). Eia hou, hōʻike nā helu liʻiliʻi o CO a me C=O i ka palena o ka solvolysis o F-NMC811. Ma ka F1s spectrum o XPS (Figure 5c), ua hōʻike ʻo F-NMC811 i kahi hōʻailona LiF ikaika, e hōʻoia ana aia ka CEI i kahi nui o LiF i loaʻa mai nā solvents fluorinated. ʻO ka palapala 'āina o nā mea F, O, Ni, Co, a me Mn ma ka ʻāpana kūloko ma nā ʻāpana F-NMC811 e hōʻike ana ua puʻunaue like ʻia nā kikoʻī ma ke ʻano holoʻokoʻa (Figure 5d). ʻO ke kiʻi TEM haʻahaʻa haʻahaʻa ma ka Figure 5e e hōʻike ana e hiki i ka CEI ke hana ma ke ʻano he pale pale e uhi like i ka electrode maikaʻi NMC811. No ka hōʻoia hou ʻana i ka hoʻololi ʻana o ka hana, ua hoʻokō ʻia nā hoʻokolohua electron microscopy (HAADF-STEM a me ka microscopy electron microscopy (ABF-STEM). -NMC811), Ka ili o ka circulating maikaʻi electrode ua undergone a koʻikoʻi manawa hoʻololi, a me ka pōhaku disordered wahi paakai ua hoahu ma ka ili o ka maikai electrode (Figure 5f) No ka perfluorinated electrolyte, ka ili o ka F-NMC811 ʻO ka electrode maikaʻi e mālama i kahi ʻano papa (Figure 5h), e hōʻike ana i ka pōʻino Ua hoʻopau maikaʻi ʻia ka māhele. ʻO ka papa CEI ma ka ʻili electrode maikaʻi o NMC811 i ka electrolyte perfluorinated.

Kiʻi 6a) TOF-SIMS spectrum o ka interphase phase ma ka ʻili o ka NMC811 electrode maikaʻi. (ac) Ka hoʻopololei ʻana i nā ʻāpana ion lua ma ka electrode maikaʻi o NMC811. (df) TOF-SIMS kemika kikoo o ka lua o ka ion ma hope o 180 kekona o ka sputtering ma ke kumu, C-NMC811 a me F-NMC811.

ʻO nā ʻāpana C2F ka mea maʻamau i manaʻo ʻia he mau mea olaola o CEI, a ʻo nā ʻāpana LiF2- a me PO2 i manaʻo pinepine ʻia he ʻano ʻano ʻano. Ua loaʻa nā hōʻailona hoʻonui nui o LiF2- a me PO2- i ka hoʻokolohua (Figure 6a, b), e hōʻike ana i ka papa CEI o F-NMC811 i loaʻa i kahi helu nui o nā ʻano inorganic. ʻOi aku ka nawaliwali o ka C2F-signal o F-NMC811 ma mua o ko C-NMC811 (Figure 6c), ʻo ia hoʻi, ʻo ka papa CEI o F-NMC811 he mau ʻano mea ola palupalu liʻiliʻi. Ua ʻike hou ʻia kahi noiʻi (Figure 6d-f) he nui nā ʻano mea ʻole i loko o ka CEI o F-NMC811, ʻoiai ʻoi aku ka liʻiliʻi o nā ʻano inorganic ma C-NMC811. Hōʻike kēia mau hopena a pau i ke kūkulu ʻia ʻana o kahi papa CEI waiwai waiwai inorganic paʻa i loko o ka electrolyte perfluorinated. Ke hoʻohālikelike ʻia me ka pā uila NMC811/Gr me ka hoʻohana ʻana i ka electrolyte kuʻuna, hiki ke hoʻopili ʻia ka hoʻomaikaʻi ʻana i ka palekana o ka pā palahe e hoʻohana ana i ka electrolyte perfluorinated: ʻO ka mua, ʻo ka hoʻokumu ʻana i loko o kahi papa CEI i waiwai i ka LiF inorganic. ʻO ke kūpaʻa wela maoli o ka electrode maikaʻi NMC811 hauʻoli e hōʻemi i ka hoʻokuʻu ʻana o ka oxygen lattice i hana ʻia e ka hoʻololi ʻana; ʻO ka lua, ʻo ka paʻa paʻa paʻa ʻole CEI e pale aku i ka delithiation reactive NMC811 mai ka hoʻopili ʻana i ka electrolyte, e hōʻemi ana i ka hopena ʻaoʻao exothermic; ʻO ke kolu, ʻO ka electrolyte perfluorinated he kūpaʻa wela kiʻekiʻe ma nā wela kiʻekiʻe.

Hopena a me Outlook

Ua hōʻike kēia hana i ka hoʻomohala ʻana o kahi pahu pahu piha piha Gr/NMC811 me ka hoʻohana ʻana i kahi electrolyte perfluorinated, i hoʻomaikaʻi nui i kāna hana palekana. Paʻa wela intrinsic. He noiʻi hohonu o ka TR inhibition mechanical a me ka pilina ma waena o nā mea a me nā pae pākaukau. ʻAʻole pili ke kaʻina hana ʻelemakule i ka TR trigger temperature (T2) o ka pākahi electrolyte perfluorinated i ka wā o ka ʻino holoʻokoʻa, he ʻoi aku ka maikaʻi ma mua o ka pākaukau kahiko e hoʻohana ana i ka electrolyte kuʻuna. Eia hou, ua kūlike ka peak exothermic me nā hopena TR, e hōʻike ana i ka ikaika o ka CEI i ka paʻa wela o ka electrode maikaʻiʻole lithium a me nā mea'ē aʻe. Hōʻike kēia mau hualoaʻa i ka hoʻolālā mana in-situ o ka papa CEI paʻa he kumu alakaʻi koʻikoʻi koʻikoʻi no ka hoʻohana pono ʻana o nā ʻeke lithium ikaika kiʻekiʻe.

ʻIke palapala

Hiki i nā ʻaoʻao ʻokoʻa Ultraconformal i kūkulu ʻia ke Kiʻekiʻe-Safety Practical Lithium Batteries, nā mea mālama ikehu, 2021.