Kayan cathode shine tushen farko na ions lithium a cikin wanilithium -batir. A lokacin caji, ana fitar da ions lithium daga lattice crystal kayan cathode kuma a shigar da kayan anode; juyawa yana faruwa yayin fitarwa. Ƙarfin jujjuyawar ƙarfi da farantin wutar lantarki na kayan cathode yayin caji da fitarwa suna ƙayyade yawan kuzarin baturin lithium{2}}. Bugu da ƙari, saboda kayan cathode ya ƙunshi ƙarfe kamar lithium, cobalt, da nickel, ya zama mafi mahimmancin ɓangaren farashin batirin lithium{4}}.
Haɓaka kayan cathode tare da ƙarfin ƙarfin ƙarfi, ƙarfin fitarwa mai ƙarfi, tsawon rayuwar sabis, da sauƙin ƙirƙira yana da mahimmanci. Kyakkyawan kayan cathode ya kamata ya dace da yanayin asali masu zuwa.
(1) Yana da babban yuwuwar redox, yana tabbatar da babban ƙarfin fitarwa don baturi.
(2) Zai iya ɗaukar ion lithium da yawa gwargwadon yiwuwa, yana tabbatar da ƙarfin baturi mai girma.
(3) A lokacin shigarwa da cirewar ions na lithium, kayan cathode na iya kula da kwanciyar hankali na tsarinsa, don haka tabbatar da tsawon rayuwar zagayowar lantarki.
(4) Ya mallaki ingantacciyar wutar lantarki da ion conductivity, yadda ya kamata yana rage asarar makamashi ta hanyar tasirin polarization, don haka tabbatar da saurin cajin baturi da iya fitarwa.
(5) Ya kamata kewayon ƙarfin aiki na baturi ya kasance a cikin kewayon kwanciyar hankali na electrolyte, ta yadda za a rage halayen sinadarai marasa mahimmanci tsakanin kayan lantarki da lantarki.
(6) Ba wai kawai ya kamata ya kasance yana da ƙananan farashi da tsari mai sauƙi ba, amma ya kamata ya nuna babban abokantaka na muhalli.
Bugu da ƙari kuma, kayan cathode ya kamata su nuna kyakkyawan yanayin lantarki da kwanciyar hankali na thermal.
Za a iya raba kayan cathode da ke wanzu zuwa kashi uku bisa ga bambance-bambancen tsarin su na crystal: ① tsarin da aka yi da shi, kamar lithium cobalt oxide (LiCoO2) da kayan ternary (LiNiCo, Mni-x-yO2); ② Tsarin olivine, irin su lithium iron phosphate (LiFePO4); ③ tsarin sinadarai oxides, irin su lithium manganese oxide (LiMn2O4) da lithium nickel manganese oxide (LiNi10.5Mn1.5O4). Daban-daban na cathodes suna da nau'ikan makamashi daban-daban, halayen electrochemical, da farashi, a ƙarshe yana sa su dace da filayen daban-daban da yanayin aikace-aikacen. Kayayyakin sifofi na sinadarai suna nufin kayan cathode tare da tsarin microcrystalline mai shimfiɗa, musamman waɗanda suka haɗa da lithium cobalt oxide, lithium nickel cobalt manganese oxide, da lithium{12}} arziƙin manganese oxide. Daga cikin su, lithium cobalt oxide da lithium nickel cobalt manganese oxide a halin yanzu sune mafi amfani da kayan cathode don lithium{14}}batir ion a cikin samfuran lantarki na dijital da batir lithium mai ƙarfi{15}}. Ana siffanta su da ƙarfin ƙarfin ƙarfi, kyakkyawan aikin sake zagayowar, da kyakkyawan aiki gabaɗaya, amma yawan adadin karafa irin su nickel, cobalt, da manganese yana haifar da ƙarin farashi.
Lithium cobalt oxide cathode abu
Lithium cobalt oxide (LiCoO2) masanin kimiyyar Amurka ne kuma wanda ya sami lambar yabo ta Nobel a Chemistry, JB Goodenough, kuma Sony Corporation na Japan ya fara kasuwa a cikin 1990s. Ko da a yau, lithium cobalt oxide ya kasance ɗayan kayan cathode tare da mafi girman ƙarfin kuzari. Don haka, ana amfani da shi sosai a cikin samfuran jakar salula na dijital waɗanda ke buƙatar ƙarfin ƙarfin ƙarfi mai ƙarfi, kamar wayoyin hannu, smartwatches, da na'urar kai ta Bluetooth.
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). Bugu da ƙari, LiCoO2 yana nuna ingantacciyar haɓakar lantarki da ionic, ingantaccen ƙarfi, da sauri{3}halayen caji, biyan buƙatun baturan lantarki na yanzu kuma don haka yana da aikace-aikace iri-iri. Dangane da waɗannan kaddarorin, LiCoO2 ya kasance ɗayan mafi kyawun kayan cathode har zuwa yau.
Babban hanyoyin haɗakarwa don lithium cobalt oxide sun haɗa da babban -zazzabi mai ƙarfi{1}}haɗin yanayi, sol{2}}gel synthesis, da ƙananan zafin zafi. Babban -ƙarfin zafin jiki{6}haɗin jihar ya ƙunshi haɗakar gishirin lithium da cobalt{7}mai ɗauke da oxides ko hydroxides a cikin ƙayyadadden rabo na stoichiometric, sannan a lissafta cakuda a yanayin da ya dace na wani ɗan lokaci, sannan sanyaya, juyewa, da sieving don samun samfurin. Ko da yake ana amfani da hanyar haɗaɗɗun yanayi mai ƙarfi -ƙarfin zafin jiki a cikin samar da masana'antu, lokaci ya yi{11}}cinyewa, yana buƙatar yanayin zafi mai yawa, kuma yana samar da manyan foda masu kama da juna tare da manyan karkatattun stoichiometric, yana haifar da ƙaƙƙarfan haɓakar farashi.
Phosphate cathode kayan
A cikin 1997, Goodenough et al. na farko da aka fara ba da shawarar lithium iron phosphate (LiFePO4) azaman kayan cathode don batirin lithium{3}}.
Saboda ƙarancin tsadarsa, tsayayyen tsarinsa, da babban aminci, wannan kayan a hankali ya zama ɗaya daga cikin abubuwan da aka fi so na cathode don batirin lithium{0} ion a cikin motocin bas ɗin lantarki da tsarin ajiyar makamashi.
Lithium iron phosphate (LiFePO4) yana raba irin wannan tsarin crystal da tsarin crystal tare da baƙin ƙarfe phosphate (FePO4). Wannan yana nufin cewa kayan suna ɗan ɗanɗano canjin ƙara yayin sakawa/haɗewar lithium, yadda ya kamata yana hana lalacewar lattice ta hanyar faɗaɗa ƙara ko ƙaranci. Bugu da ƙari kuma, wannan sifa tana tabbatar da kyakkyawar hulɗar lantarki tsakanin barbashi da abubuwan haɓakawa, yana haifar da kyakkyawan kwanciyar hankali na sake zagayowar da tsawon rayuwa. Bugu da kari, lithium iron phosphate ya shahara saboda abokantakar muhallinsa, farashi{6} inganci, kyakkyawan aminci, babban takamaiman iya aiki (kimanin 170 mA·h/g), da kuma bargaren caji/shari. Ganin waɗannan fa'idodin, ana ɗaukar lithium iron phosphate a matsayin kyakkyawan zaɓi don kayan cathode a cikin manyan aikace-aikacen ajiyar makamashi mai girma{9}.
Hanyoyin sun haɗa da tafiyar matakai na sol{0}gel, dabarun haɗe-haɗe, da haɗin ruwa. Musamman, haɗin hydrothermal kai tsaye yana haifar da samfurin da aka yi niyya a cikin autoclave ta hanyar ƙara yawan zafin jiki da matsa lamba, ta amfani da ƙarfe, lithium, da mahadi na phosphorus da ke samuwa a matsayin albarkatun ƙasa. An san wannan hanyar don sauƙin aiki, ƙanana da girman nau'in ƙwayar cuta, da ƙarancin amfani da makamashi. Koyaya, yana da iyakancewa don samarwa masana'antu, da farko saboda buƙatar ƙira ta musamman matsi{4}} kwantena masu jurewa. Ƙwaƙwalwar ƙira, a gefe guda, ana gudanar da shi a cikin tsarin warwarewa, inda tsarin ilimin halittar farko ya shafi abubuwa daban-daban irin su maida hankali, kula da zafin jiki, daidaitawar pH, da ƙimar motsawa. Ganin muhimmiyar rawar da waɗannan sigogi ke takawa wajen aiwatar da kayan aikin LiFePO na ƙarshe, zaɓin yanayi na gwaji a hankali yana da mahimmanci. Kayayyakin da aka shirya ta wannan hanyar ba wai kawai suna da kyawawan halaye na microstructure ba (watau ƙanana da girman nau'in ƙwayar cuta) amma kuma suna nuna manyan kaddarorin electrochemical; duk da haka, yana da kyau a lura cewa duk tsarin aiki yana da rikitarwa, kuma ƙalubalen tacewa da al'amuran sarrafa sharar gida na iya tasowa yayin sarrafawa.
Lithium manganese oxide da lithium{0}}manganese mai arzikin manganese{1} tushen cathode kayan
Lithium manganese oxide
A cikin binciken kayan cathode na lithium{0}ion baturi, wani muhimmin abu kuma na kasuwanci akwai kayan cathode shine spinel -tsararriyar lithium manganese oxide (LiMn₂O₄) kayan cathode da Thackeray et al suka gabatar. a cikin 1983. Spinel -tsararriyar lithium manganese oxide na cikin tsarin kubik crystal. Tsarin sinadaransa na yau da kullun shine LiMn₂O₄. A cikin tsarin lu'ulu'u na LiMn₂O₄, iskar oxygen yana cikin fuska{7}}tsakiyar kubik kusa -tsari, yayin da manganese da oxygen ke samar da tsarin octahedral, kamar yadda aka nuna a hoton da ke ƙasa.
Manganese yana da yawa a cikin yanayi, kuma dabarun shirye-shiryen don spinel{0} nau'in lithium manganese oxide (LiMn2O4) yana nuna halaye iri-iri. Hanyar haɗakarwa da fasahar sarrafa kayan abu kai tsaye suna shafar microstructure da ci gaban hatsi na samfurin ƙarshe. Don haka, inganta waɗannan hanyoyin haɗin gwiwar yana da mahimmanci don haɓaka aikin lantarki na kayan lantarki a aikace-aikace masu amfani. A halin yanzu, masana'antu da masana kimiyya suna amfani da manyan nau'ikan hanyoyi guda biyu don shirya LiMn2O4: ɗaya yana dogara ne akan hulɗar daɗaɗɗen albarkatun ƙasa, kamar su -ƙarfin zafin jiki{9}halayen yanayi, haɓakar microwave{10}taimakon ƙira, da maganin ciki a cikin narkakkar watsa labarai na gishiri.
Wani nau'in ya haɗa da canjin sinadarai a cikin muhallin ruwa, tare da misalan misalan da suka haɗa da fasahar sol{0}, haɗaɗɗiyar ruwa, da dabarun haɓaka. LiMnzO4 ya ja hankalin jama'a sosai saboda fa'idar farashinsa, kyakkyawan kwanciyar hankali na zafi, juriya mai ƙarfi mai ƙarfi, da fa'idodin muhalli masu kyau. Duk da haka, wannan kayan yana da nakasu a cikin hawan keke da aikin ajiya, musamman a yanayin zafi mai yawa, inda aikin hawan keke ya lalace sosai, yana haifar da asarar ƙarfin da ba za a iya jurewa ba.
lithium -mai arzikin manganese{1}
Bayan lithium manganese oxide, lithium mai lankwasa{0}}manganese{1} tushen kayan sun ja hankalin jama'a a matsayin kayan cathode da ke fitowa don batirin lithium{2}ion.
Hanyoyi na shirye-shiryen lithium{0}manganese mai arzikin manganese{1}}ananan kayan cathode sun haɗa da ƙwararrun hanyoyin{2}}hanyoyin jiha, hanyoyin sol-gel, da hanyoyin hazo{4}. Ƙarfin -Hanyar jiha ta ƙunshi haɗakar oxides na ƙarfe kai tsaye da carbonates na ƙarfe ko ƙarfe hydroxides a cikin wani ƙayyadadden ƙayyadaddun ƙayyadaddun ƙayyadaddun ƙayyadaddun yanayi, sannan kuma zazzaɓi mai ƙarfi{{8}hala don samun kayan lithium mai laushi{9}}. Fa'idodin ƙaƙƙarfan hanyar jiha shine ikonsa na haɗa ɗimbin kayan lithium mai laushi, hanyar shiryarsa mai sauƙi, da ƙarancin farashi. Lalacewar ita ce rashin wadataccen ma'auni na ƙaƙƙarfan ƙaƙƙarfan lokacin daɗaɗɗen jaha, da kuma gaskiyar cewa nau'ikan ƙarafa daban-daban suna da ƙimar yaduwa daban-daban a cikin ingantaccen yanayin yanayi, yana da wahala ga barbashi don yaduwa sosai. Sabili da haka, daidaituwar kayan da aka haɗa ba shi da kyau, wanda ke shafar aikin kayan aikin cathode. Hanyar sol -gel ta ƙunshi da farko ƙara maganin gishirin ƙarfe na tsaka-tsaki ga na'ura mai haɗawa don samar da sol, sannan a fitar da ruwan don ya zama gel, sannan a bushe da kuma sanya shi don samun kayan arziƙi na lithium{19}}. Wannan hanyar tana samar da kayan aiki tare da rarraba iri ɗaya da tsafta mai yawa, kuma na'urorin lantarki da aka samar suna nuna kyakkyawan aikin lantarki. Koyaya, abubuwan da ke tattare da shi sun haɗa da sake zagayowar ƙirƙira mai tsayi, buƙatar masu haɗawa da yawa (kwayoyin halitta ko ethylene glycol), wanda ke haifar da tsada mai tsada. Bugu da ƙari, arziƙin lithium ɗin da aka kera{23}} galibin ɓangarorin nano/micron ne masu ƙarancin gaske. Don haka, a halin yanzu ana amfani da wannan hanyar da farko a cikin saitunan dakin gwaje-gwaje don ƙirƙira kayan lithium mai laushi{25}} kuma yana da wahalar kasuwanci.
Babban{0} nickel cathode kayan
Masu bincike sun dade suna neman kwanciyar hankali mai girma{0} da kyakkyawan aiki a matsayin maƙasudin farko lokacin haɓaka cathode
kayan don batirin lithium{0}ion. Daga cikin manyan abubuwa guda uku - LiCoO₂, LiNi₁ₓ₋ᵧCoₓMnᵧO₂ (NCM), da LiFePO₄ - NCM ana ɗaukarsa ɗaya daga cikin mafi kyawun kayan cathode saboda girman takamaiman ƙarfinsa, ƙarancin ƙarancin albarkatun ƙasa, ƙimar muhalli mafi kyau idan aka kwatanta da LiCoO.
Irin wannan nau'in kayan yana da nau'in nau'in nau'in nau'in nau'in nau'in crystal na {{0}NaFeO₂- kuma yana cikin rukunin sararin samaniya na R{6} 3m. Liu et al ne ya fara gabatar da wannan ra'ayi. a cikin 1999. Yana da wayo ya haɗu da fa'idodin kayan cathode guda uku - lithium cobalt oxide (LiCoO₂), lithium nickel oxide (LiNiO₂), da lithium manganese oxide (LiMnO₂) - kuma yana ramawa da kyau ga gazawar da aka nuna a cikin kowane mutum 5. Ta hanyar daidaita ma'auni na abubuwan ƙarfe na canji, mafi kyawun ma'auni tsakanin ƙayyadaddun iya aiki, aikin sake zagayowar, aminci, da farashi za'a iya ƙara samun nasara.
Tsarin lu'ulu'u na lithium nickel cobalt manganese oxide (NCM) ternary cathode abu shine ainihin iri ɗaya da na LiCoO2, duka na cikin tsari mai launi hexagonal.
