Izinto ze-cathode ngumthombo oyintloko we-lithium ion kwi-alithium -ibhetri ye-ion. Ngexesha lokutshaja, i-lithium ion ikhutshwe kwi-crystal lattice ye-cathode kwaye ifake izinto ze-anode; umva kwenzeka ngexesha lokukhupha. Umthamo obuyiselwa umva kunye neplateau yombane wemathiriyeli yecathode ngexesha lokutshaja kunye nokukhupha ubukhulu becala kumisela ukuxinana kwamandla ebhetri ye-lithium{2}}yeion. Ngaphaya koko, ngenxa yokuba i-cathode iqulethe iintsimbi ezifana ne-lithium, i-cobalt, kunye ne-nickel, yenza eyona nxalenye ibalulekileyo yexabiso lebhetri ye-lithium-.
Ukuphuhliswa kwemathiriyeli yecathode enoxinano lwamandla aphezulu, amandla ombane aphezulu, ubomi benkonzo ende, kunye nokulula kokwenziwa kubaluleke kakhulu. Isixhobo esifanelekileyo se-cathode kufuneka sihlangabezane nale miqathango ilandelayo.
(1) Inamandla aphezulu e-redox, eqinisekisa amandla ombane aphezulu ebhetri.
(2) Iyakwazi ukwamkela i-lithium ion ezininzi kangangoko kunokwenzeka, iqinisekisa umthamo webhetri ophezulu.
(3) Ngethuba lokufakwa kunye nokukhutshwa kwee-ion ze-lithium, izinto ze-cathode ziyakwazi ukugcina ukuzinza kwayo kwesakhiwo, ngaloo ndlela iqinisekisa ubomi bomjikelezo omude we-electrode.
(4) Iphethe i-electronic kunye ne-ion conductivity egqwesileyo, inciphisa ngokufanelekileyo ilahleko yamandla ebangelwa yimiphumo ye-polarization, ngaloo ndlela iqinisekisa ukutshaja ngokukhawuleza kwebhetri kunye nokukhupha amandla.
(5) Uluhlu lwamandla ombane osebenzayo lwebhetri kufuneka lube kuluhlu lokuzinza kwe-electrochemical ye-electrolyte, ngokwenjenjalo kuncitshiswe ukusabela kweekhemikhali okungeyomfuneko phakathi kwemathiriyeli ye-electrode kunye ne-electrolyte.
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Ngapha koko, imathiriyeli ye-cathode kufuneka ibonise i-electrochemical egqwesileyo kunye nokuzinza kwe-thermal.
Izinto ezikhoyo ze-cathode zinokwahlulwa ikakhulu zibe ziindidi ezintathu ezisekelwe kumahluko wesakhiwo sekristale: ① ulwakhiwo olunemaleko, njenge-lithium cobalt oxide (LiCoO2) kunye nezixhobo ze-ternary (LiNiCo, Mni{1}}x{2}}yO2); ② isakhiwo se-olivine, njenge-lithium iron phosphate (LiFePO4); ③ i-spinel structure oxides, njenge-lithium manganese oxide (LiMn2O4) kunye ne-lithium nickel manganese oxide (LiNi10.5Mn1.5O4). Iindidi ezahlukeneyo ze-cathode zinoxinzelelo oluhlukeneyo lwamandla, iimpawu ze-electrochemical, kunye neendleko, ekugqibeleni zizenza zilungele imimandla eyahlukeneyo kunye neemeko zesicelo. Ulwakhiwo olumaleko lwemathiriyeli ye-cathode lubhekiselele kwimathiriyeli ye-cathode enobume be-microcrystalline enemaleko, ingakumbi i-lithium cobalt oxide, i-lithium nickel cobalt manganese oxide, kunye ne-lithium{12}}i-manganese oxide etyebileyo. Phakathi kwazo, i-lithium cobalt oxide kunye ne-lithium nickel cobalt manganese oxide okwangoku zezona zinto zisetyenziswa kakhulu kwicathode yelithium{14}}ibhetri zeion kwiimveliso zombane zedijithali kunye namandla e-lithium{15}}ibhetri zeion. Ziphawulwa kukuxinana kwamandla aphezulu, ukusebenza komjikelo okugqwesileyo, kunye nokusebenza kakuhle kukonke, kodwa umlinganiselo ophezulu wesinyithi njenge-nickel, i-cobalt, kunye ne-manganese ikhokelela kwiindleko eziphezulu.
Izinto ze-lithium cobalt oxide cathode
I-Lithium cobalt oxide (i-LiCoO2) yafunyanwa ngusosayensi waseMelika kunye neNobel laureate kwiKhemistry, uJB Goodenough, kwaye yaqala ukuthengiswa nguSony Corporation yaseJapan kwi-1990s. Nanamhla oku, i-lithium cobalt oxide ihlala iyenye yezixhobo ze-cathode ezinobuninzi be-volumetric energy density. Ngesi sizathu, isetyenziswa kakhulu kwiimveliso zeeselfowuni zedijithali ezifuna uxinaniso lwamandla aphezulu, njengeefowuni eziphathwayo, ii-smartwatches, kunye nee-headsets zeBluetooth.
Lithium cobalt oxide (LiCoO2), as one of the earliest commercially available cathode materials, possesses a volumetric energy density unmatched by other cathode materials. Electrodes prepared from LiCoO2 can achieve a compaction density exceeding 4.2 g/cm², and a specific capacity of 185 mA·h/g at high voltage (>4.45V). Ngaphaya koko, i-LiCoO2 ibonisa ukusebenza kakuhle kwe-elektroniki kunye ne-ionic, ukusebenza kakuhle kwamandla, kunye neempawu zokutshaja ezikhawulezayo-, ukuhlangabezana neemfuno zangoku zeebhetri ze-electronics zangoku kwaye zibenoluhlu olubanzi lwezicelo. Ngokusekwe kwezi propati, i-LiCoO2 ihlala iyenye yezona zinto zibalaseleyo ze-cathode ukuza kuthi ga ngoku.
Ezona ndlela zokudityaniswa kwe-lithium cobalt oxide ziquka phezulu-ubushushu obuqinileyo{1}}ubume bemeko, i-sol-i-gel synthesis, kunye{3}}nobushushu obuphantsi. Umgangatho ophezulu-oluqilima lobushushu{6}}ukwenziwa kwelizwe kubandakanya ukuxuba iityuwa zelithium kunye necobalt{7}}equlathe iioksidi okanye iihydroxides kumlinganiselo othile we-stoichiometric, emva koko kufakwe umxube kwiqondo lobushushu elifanelekileyo ixesha elithile, kulandelwa kukupholisa, ukucolwa, kunye nokuhluzwa ukufumana isampuli. Nangona iqondo eliphezulu{9}}iqondo lobushushu eliqinileyo{10}}indlela yokwenziwa kwelizwe isetyenziswa kakhulu kwimveliso yemizi-mveliso, lixesha{11}}elityayo, lifuna amaqondo obushushu ahlanganisiweyo aphezulu, kwaye livelisa umgubo omkhulu, ongalinganiyo one-homogeneous kunye nokunxaxha okubalulekileyo kwe-stoichiometric, okukhokelela ekonyukeni okukhulu kweendleko.
Izinto ze-phosphate cathode
Ngowe-1997, uGoodenough et al. i-lithium iron phosphate yokuqala ecetywayo (LiFePO4) njengesixhobo se-cathode se-lithium -ibhetri ze-ion.
Ngenxa yeendleko eziphantsi, isakhiwo esizinzile, kunye nokhuseleko oluphezulu, le nto iyancipha ngokuthe ngcembe enye yezinto ezikhethiweyo ze-cathode ze-lithium- iibhetri ze-ion kwiibhasi zombane kunye neenkqubo zokugcina amandla.
I-Lithium iron phosphate (LiFePO4) yabelana ngesakhiwo esifanayo se-crystal kunye nenkqubo ye-crystal kunye ne-iron phosphate (FePO4). Oku kuthetha ukuba izinto eziphathekayo zifumana utshintsho oluncinci ngexesha le-lithium - yokufakwa kwe-ion / ukukhutshwa, ngokufanelekileyo ukuthintela umonakalo we-lattice obangelwa ukwandiswa komthamo okanye ukuchithwa. Ngaphezu koko, olu phawu luqinisekisa unxibelelwano olulungileyo lombane phakathi kwamasuntswana kunye nezongezo eziqhubayo, okukhokelela ekuzinzeni komjikelo ogqwesileyo kunye nobomi obude. Ukongeza, i-lithium iron phosphate idume ngokusebenzelana nokusingqongileyo, iindleko -ezisebenzayo, ukhuseleko olugqwesileyo, umthamo othe ngqo ophezulu (malunga ne-170 mA·h/g), kunye neqonga elizinzileyo lokuhlawulisa/lokukhupha. Xa kujongwa olu ncedo, i-lithium iron phosphate ithathwa njengokhetho olufanelekileyo kwimathiriyeli ye-cathode kusetyenziso olukhulu logcino lwamandla.
Iindlela ziquka isol-iinkqubo zejeli, ubuchule bokufumana icoprecipitation, kunye ne-hydrothermal synthesis. Ngokukodwa, i-hydrothermal synthesis ivelisa ngokuthe ngqo imveliso ekujoliswe kuyo kwi-autoclave ngokunyusa izinga lokushisa kunye noxinzelelo, usebenzisa i-iron efumaneka ngokulula, i-lithium, kunye ne-phosphorus compounds njengezinto ezibonakalayo. Le ndlela yaziwa ngokusebenza kwayo okulula, ubungakanani bamasuntswana amancinci kunye afanayo, kunye nokusetyenziswa kwamandla aphantsi. Nangona kunjalo, inemida kwimveliso yemizi-mveliso, ngenxa yesidingo soxinzelelo oluyilwe ngokukodwa{4}}izikhongozeli ezixhathisayo. I-Coprecipitation, ngakolunye uhlangothi, iqhutyelwa kwinkqubo yesisombululo, apho i-morphology ye-precursor ichaphazelekayo yizinto ezahlukeneyo ezifana nokugxininiswa, ukulawulwa kweqondo lokushisa, ukulungiswa kwe-pH, kunye nezinga lokuvuselela. Ukunikezelwa kwendima eqinisekileyo ezi pharamitha zidlalayo ekusebenzeni kwemathiriyeli ye-sintered ye-LiFePO yokugqibela, ukukhetha ngononophelo kweemeko zovavanyo kubalulekile. Iimveliso ezilungiselelwe ngale ndlela azinakuba neempawu ezibalaseleyo ze-microstructure kuphela (oko kukuthi, ubungakanani bamasuntswana amancinane kunye nobunye) kodwa zikwabonisa iimpawu eziphezulu ze-electrochemical; nangona kunjalo, kubalulekile ukuqaphela ukuba yonke inkqubo yokusebenza inzima kakhulu, kwaye imingeni yokucoca kunye nemiba yokulawula inkunkuma inokuvela ngexesha lokucubungula.
I-lithium manganese oxide kunye ne-lithium-i-manganese etyebileyo{1}esekelwe kwimathiriyeli ye-cathode
Lithium manganese oxide
Kuphando lwe-lithium -i-ion ye-cathode ye-cathode imathiriyeli, enye into ebalulekileyo kunye neyorhwebo ekhoyo ye-cathode yi-spinel{1}}i-lithium manganese oxide eyakhiweyo (LiMn₂O₄) yecathode ecetywa nguThackeray et al. ngo 1983. Ubume bayo beekhemikhali eziqhelekileyo yi-LiMn₂O₄. Kulwakhiwo lwekristale ye-LiMn₂O₄, ioksijini ikubuso{7}}kumbindi we-cubic esondele{8}}isakhiwo esipakishiweyo, ngelixa i-manganese kunye neoksijini zenza ulwakhiwo lwe-octahedral, njengoko kubonisiwe kulo mfanekiso ungezantsi.
IManganese ininzi ngokwendalo, kwaye ubuchule bokulungiselela i-spinel{0}}uhlobo lwe-lithium manganese oxide (LiMn2O4) ibonisa iimpawu ezahlukeneyo. Indlela yokudibanisa kunye neteknoloji yokucubungula izinto ezichaphazela ngokuthe ngqo i-microstructure kunye nophuhliso lwengqolowa yemveliso yokugqibela. Ke ngoko, ukwenziwa ngcono kwezi nkqubo zokudibanisa kubalulekile ekuphuculeni ukusebenza kwe-electrochemical yemathiriyeli ye-electrode kwizicelo ezisebenzayo. Okwangoku, ishishini kunye nemfundo ephakamileyo zisebenzisa iindlela ezimbini eziphambili zokulungiselela i-LiMn2O4: enye isekwe kwintsebenziswano phakathi kwemathiriyeli ekrwada eqinileyo, efana -nobushushu obuphezulu{9}}ukusabela kombuso, ukudityaniswa kwe-microwave{10}}, kunye nonyango lokufakwa kwimithombo yetyuwa etyhidiweyo.
Olunye udidi lubandakanya uguqulo lweekhemikhali kwimeko-bume yolwelo, kunye nemizekelo eqhelekileyo equka i-sol-iteknoloji yejeli, i-hydrothermal synthesis, kunye nobuchule bokufumana i-coprecipitation. I-LiMnzO4 itsale ingqwalaselo ebanzi ngenxa yenzuzo yexabiso layo, uzinzo olubalaseleyo lwe-thermal, ukuxhathisa okunamandla kokuchasa, kunye neenzuzo ezilungileyo zokusingqongileyo. Nangona kunjalo, esi sixhobo sineziphene ekusebenzeni kwebhayisikile kunye nokugcinwa, ngakumbi kumaqondo okushisa aphezulu, apho ukusebenza kwayo kwebhayisikile kuhla kakhulu, okukhokelela ekulahlekelweni kwamandla okungenakuguqulwa.
i-lithium{0}i-manganese etyebileyo{1}esekwe
Ngaphandle kwe-lithium manganese oxide, i-lithium eleleyo -i-manganese etyebileyo{1}}izinto ezisekwe kwimathiriyeli zitsale ingqwalasela ebanzi njengemathiriyeli yecathode esakhulayo yeebhetri ze-lithium{2}}.
Iindlela zokulungiselela i-lithium-i-manganese etyebileyo-esekelwe kwimathiriyeli ye-cathode iquka iindlela eziqinileyo-iindlela zelizwe, iindlela ze-sol-ijeli, kunye{4}}neendlela zemvula. Indlela eqinileyo -karhulumente ibandakanya ukuxuba ngokuthe ngqo iioksidi zentsimbi kunye nekhabhonithi zentsimbi okanye ihydroxides zetsimbi kumyinge othile, ilandelwa ngumgangatho ophezulu{7}}oluqilima lobushushu{8}}ukusabela kombuso ukufumana umaleko we-lithium{9}}izinto ezityebileyo. Uncedo lwendlela eqinileyo{11}}kukwazi kwayo ukwenza ubungakanani obukhulu be-lithium elayitiweyo{12}}izixhobo ezityebileyo, indlela yayo yokulungisa elula, kunye nexabiso layo eliphantsi. Ububi bubunzima bokusasazwa komlinganiso wesiqina ngexesha eliqinileyo{14}}lokuntywila kwelizwe, kunye nenyani yokuba iintsimbi zotshintsho ezahlukeneyo zinemilinganiselo yosasazo olwahlukileyo kwindawo eqinileyo{15}}impendulo yemeko, isenza kubenzima ukuba amasuntswana asasazeke ngokwaneleyo. Ngoko ke, ukufana kwezinto ezixutywe kakuhle, ezichaphazela ukusebenza kwezinto ze-cathode. Indlela yesol{18}}yejeli ibandakanya kuqala ukongeza isisombululo setyuwa yesinyithi kwisihlanganisi ukwenza isol, emva koko ikhuphe amanzi abe ngumphunga ukuyenza ijeli, kwaye ekugqibeleni uyomise kwaye uyibale ukuze ufumane umaleko we-lithium{19}}izinto ezityebileyo. Le ndlela ivelisa izinto ezinokusabalalisa okufanayo kunye nokucoceka okuphezulu, kwaye i-electrode eveliswayo ibonisa ukusebenza kakuhle kwe-electrochemical. Nangona kunjalo, iintsilelo zayo ziquka umjikelezo omude wokwenza izinto, imfuno yokudibanisa ezininzi (i-organic acids okanye i-ethylene glycol), okubangelwa iindleko eziphezulu. Ngaphaya koko, i-lithium evelisiweyo{23}}yemathiriyeli etyebileyo ubukhulu becala ngamasuntswana e-nano/micron anoxinano oluphantsi. Ke ngoko, le ndlela ngoku isetyenziswa ikakhulu kwizicwangciso zaselabhoratri ukwenza i-lithium elayitiweyo{25}}izixhobo ezityebileyo kwaye kunzima ukuyithengisa.
{0}}Imathiriyeli ye-nickel cathode ephezulu
Abaphandi kudala befuna-uzinzo lobushushu obuphezulu kunye nomgangatho ogqwesileyo wokusebenza njengezona njongo ziphambili xa kusenziwa i-cathode.
imathiriyeli yelithium -ibhetri zeion. Phakathi kwezinto ezintathu eziphambili - iLiCoO₂, iLiNi₁ₓ₋ᵧCoₓMnᵧO₂ (NCM), kunye neLiFePO₄ - iNCM ithathwa njengenye yezona zinto zithembisayo zecathode ngenxa yomthamo wayo othe ngqo, ixabiso eliphantsi kakhulu lezinto eziphathekayo, ixabiso elingcono lezinto eziphathekayo, kunye nexabiso elingcono lokhuseleko lokusingqongileyo, i-Corior yokhuseleko lomhlobo ₂ izixhobo.
Olu hlobo lwemathiriyeli luyafana -NaFeO₂-uhlobo olufanayo lwesakhiwo sekristale kwaye yeyeqela le-R{6}}3m yesithuba. Le ngcamango yacetywa kuqala nguLiu et al. ngo-1999. Idibanisa ngobuchule izibonelelo zezinto ezintathu ze-cathode - i-lithium cobalt oxide (LiCoO₂), i-lithium nickel oxide (i-LiNiO₂), kunye ne-lithium manganese oxide (LiMnO₂) - kwaye ihlawule ngokufanelekileyo iimpazamo ezikhoyo kwi-figure nganye (njengoko kubonisiwe kwi-Figure 6). Ngokulungelelanisa umlinganiselo wezinto zetsimbi zenguqu, ibhalansi efanelekileyo phakathi komthamo othile, ukusebenza komjikelo, ukhuseleko, kunye neendleko zinokufezekiswa ngakumbi.
Ubume bekristale be-lithium nickel cobalt manganese oxide (NCM) izinto ze-ternary cathode ngokusisiseko ziyafana naleyo ye-LiCoO2, zombini ziyinxalenye yesakhiwo esinehexagonal.
