Ekintu kya katodi kye nsibuko enkulu eya lithium ions mu abbaatule ya lithium-ion. Mu kiseera ky’okucaajinga, amasannyalaze ga lithium gaggyibwa mu kisenge kya kirisitaalo ky’ekintu kya katodi ne gayingira mu kintu kya anode; eky’okudda emabega kibaawo mu kiseera ky’okufulumya. Obusobozi obukyukakyuka n’obuwanvu bwa vvulovumenti y’ekintu kya katodi mu kiseera ky’okucaajinga n’okufulumya okusinga bye bisalawo obungi bw’amasoboza ga bbaatule ya lithium-ion. Ekirala, olw’okuba ekintu kya katodi kirimu ebyuma nga lithium, cobalt, ne nickel, kye kikola ekitundu ekisinga obukulu mu nsaasaanya ya bbaatule ya lithium-ion.
Okukola ebintu bya katodi ebirina amaanyi amangi, vvulovumenti y’okufulumya enkulu, obulamu obuwanvu obw’okuweereza, n’obwangu bw’okukola kikulu nnyo. Ekintu kya katodi ekituufu kirina okutuukiriza embeera zino wammanga.
(1) Possess a high redox potential, okukakasa nti voltage efuluma waggulu eri bbaatule.
(2) Asobola okuyingiza ion za lithium nnyingi nga bwe kisoboka, okukakasa nti bbaatule erina obusobozi bwa waggulu.
(3) Mu kiseera ky’okuyingiza n’okuggyamu ayoni za lithium, ekintu kya katodi kisobola okukuuma obutebenkevu bwakyo mu nsengekera, bwe kityo ne kikakasa obulamu bw’enzirukanya empanvu eri ekiwujjo.
(4) Possesses excellent electronic ne ion conductivity, effectively ekendeeza ku kufiirwa kw’amasoboza okuva ku polarization effects, bwe kityo okukakasa bbaatule okucaajinga amangu n’okufulumya obusobozi.
(5) Voltage ya bbaatule ekola erina okuba mu bbanga ly’obutebenkevu bw’amasannyalaze ag’obusannyalazo, bwe kityo ne kikendeeza ku nkolagana ya kemiko eziteetaagisa wakati w’ekintu ky’obusannyalazo n’obusannyalazo.
(6) Tekirina kuba na ssente ntono yokka n’enkola ennyangu ey’okugatta, naye era erina okwolesa omukwano ogw’amaanyi eri obutonde bw’ensi.
Ekirala, ekintu kya katodi nakyo kisaana okulaga okutebenkera okw’amasannyalaze n’ebbugumu okulungi ennyo.
Ebintu bya katodi ebiriwo okusinga bisobola okwawulwamu ebika bisatu okusinziira ku njawulo zaabyo mu nsengekera ya kirisitaalo: 1 ensengekera ya layeri, nga lithium cobalt oxide (LiCoO2) n’ebintu eby’ekika kya ternary (LiNiCo, Mni-x-yO2); 2 ensengekera ya olivine, nga lithium iron phosphate (LiFePO4); 3 okisayidi z’ensengekera ya spinel, nga lithium manganese oxide (LiMn2O4) ne lithium nickel manganese oxide (LiNi10.5Mn1.5O4). Ebika bya katodi eby’enjawulo birina densite z’amasoboza ez’enjawulo, engeri z’amasannyalaze, n’ebisale, okukkakkana nga biba bisaanira ennimiro ez’enjawulo n’embeera z’okukozesa. Ebintu bya katodi eby’ensengekera ya layeri bitegeeza ebintu bya katodi ebirina ensengekera ya microcrystalline eya layeri, okusinga nga mulimu lithium cobalt oxide, lithium nickel cobalt manganese oxide, ne lithium-rich manganese oxide. Mu byo, lithium cobalt oxide ne lithium nickel cobalt manganese oxide mu kiseera kino bye bintu ebisinga okukozesebwa mu cathode ku bbaatule za lithium-ion mu bintu eby’amasannyalaze ebya digito ne bbaatule za lithium-ion ez’amaanyi. Zimanyiddwa olw’amasoboza amangi, okukola obulungi ennyo mu nsengekera, n’okukola obulungi okutwalira awamu, naye ekitundu ekinene eky’ebyuma nga nikele, kobalti, ne manganise kivaako ssente ennyingi.
Ekintu kya katodi ekya lithium cobalt oxide
Lithium cobalt oxide (LiCoO2) yazuulibwa munnasayansi Omumerika era eyawangudde engule ya Nobel mu Chemistry, J. B. Goodenough, era yasooka kutundibwa kkampuni ya Sony Corporation of Japan mu myaka gya 1990. Ne leero, lithium cobalt oxide esigala nga kye kimu ku bintu bya katodi ebisinga okuba n’amasoboza ag’obunene (volumetric energy density). Olw’ensonga eno, ekozesebwa nnyo mu bintu bya digito ebiyitibwa digital pouch cell ebyetaaga amaanyi amangi aga volumetric, gamba ng’amasimu, essaawa entegefu, n’ebyuma ebikozesebwa mu matu ebya 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) nga bwe kiri. Ekirala. Okusinziira ku mpisa zino, LiCoO2 esigala nga y’emu ku bintu bya katodi ebisinga obulungi okutuusa kati.
Enkola enkulu ez’okusengejja lithium cobalt oxide mulimu okusengejja ekikalu eky’ebbugumu eringi-, okusengejja sol-gel, n’okutonnya awamu okw’ebbugumu eritono-. Okusengejja ekikalu-mu bbugumu erya waggulu kuzingiramu okutabula eminnyo gya lithium ne cobalt-erimu okisayidi oba hayidirokisayidi mu mugerageranyo ogw’enjawulo ogwa stoichiometric, olwo n’okwokya omutabula ku bbugumu erisaanira okumala ekiseera ekigere, ne kigobererwa okunyogoza, okufuumuula, n’okusengejja okusobola okufuna sampuli. Newankubadde enkola ya high-temperature solid-state synthesis ekozesebwa nnyo mu kukola amakolero, etwala obudde-, yeetaaga ebbugumu ery’okusengejja erya waggulu, era efulumya obuwunga obunene, obutali bwenkanya obutafaanagana nga bulina okukyama okunene mu stoichiometric, ekivaamu okweyongera okw’amaanyi mu nsaasaanya.
Ebintu ebikozesebwa mu katodi ya phosphate
Mu 1997, Goodenough ne banne. yasooka kuteesa ku lithium iron phosphate (LiFePO4) nga ekintu kya katodi ekya bbaatule za lithium-ion.
Olw’ebbeeyi yaakyo entono, ensengekera ennywevu, n’obukuumi obw’amaanyi, ekintu kino kifuuse mpolampola ekimu ku bintu bya katodi ebisinga okwettanirwa bbaatule za lithium-ion mu bbaasi z’amasannyalaze n’enkola z’okutereka amaanyi.
Lithium iron phosphate (LiFePO4) egabana ensengekera ya kirisitaalo n’enkola ya kirisitaalo ezifaanagana ne iron phosphate (FePO4). Kino kitegeeza nti ekintu kifuna enkyukakyuka entono mu bunene mu kiseera ky’okuyingiza/okuggyamu lithium-ion, mu ngeri ennungi ne kiziyiza okwonooneka kwa lattice okuva mu kugaziwa oba okukonziba kwa voliyumu. Ekirala, engeri eno ekakasa okukwatagana okulungi kw’amasannyalaze wakati w’obutundutundu n’ebirungo ebitambuza, ekivaamu okutebenkera kw’enzirukanya ennungi ennyo n’obulamu obuwanvu. Okugatta ku ekyo, lithium iron phosphate emanyiddwa nnyo olw’obulungi bwayo eri obutonde bw’ensi, okukendeeza ku ssente-, obukuumi obulungi ennyo, obusobozi obw’enjawulo obw’amaanyi (nga 170 mA·h/g), n’omukutu ogutebenkedde ogw’okusasula/okufulumya. Okusinziira ku birungi bino, lithium iron phosphate etwalibwa ng’okulonda okulungi eri ebintu bya katodi mu nkola ennene-okutereka amaanyi.
Enkola zino mulimu enkola za sol-gel, obukodyo bw’okutonnya awamu, n’okusengejja amazzi. Okusingira ddala, okusengejja okw’amazzi mu bbugumu kukola butereevu ekintu ekigendererwa mu autoclave nga kwongera ebbugumu ne puleesa, nga tukozesa ebirungo by’ekyuma, lithium, ne phosphorus ebifunibwa amangu ng’ebintu ebisookerwako. Enkola eno emanyiddwa olw’enkola yaayo ennyangu, obunene bw’obutundutundu obutono era obw’enjawulo, n’okukozesa amaanyi amatono. Naye, erina obuzibu ku kukola mu makolero, okusinga olw’obwetaavu bw’ebintu ebikoleddwa mu ngeri ey’enjawulo ebigumira puleesa-. Ate okutonnya awamu kukolebwa mu nkola ya solution, nga enkula y’ekisookerwako ekosebwa ensonga ez’enjawulo nga okusengejja, okufuga ebbugumu, okutereeza pH, n’omutindo gw’okutabula. Kubanga omulimu ogusalawo parameters zino ze zikola mu kukola ekintu ekisembayo ekya sintered LiFePO, okulonda n’obwegendereza embeera z’okugezesa kikulu nnyo. Ebintu ebitegekebwa mu nkola eno tebikoma ku kuba na mpisa za microstructure ennungi ennyo (kwe kugamba, obunene bw’obutundutundu obutono era obw’enjawulo) naye era biraga eby’obugagga eby’amasannyalaze eby’ekika ekya waggulu; wabula kirungi okumanya nti enkola yonna ey’okukola nzibu nnyo, era okusoomoozebwa mu kusengejja n’ensonga z’okuddukanya kasasiro kuyinza okuvaayo nga balongoosa.
Lithium manganese oxide ne lithium-ebintu ebingi ebya manganese-ebikozesebwa mu katodi
Ekirungo kya lithium manganese oxide
Mu kunoonyereza ku bintu bya lithium-ion battery cathode materials, ekintu ekirala ekikulu era ekitundibwa mu katodi kye kintu kya spinel-structured lithium manganese oxide (LiMn2O4) cathode material ekyateesebwa Thackeray et al. mu 1983. Spinel-structured lithium manganese oxide eri mu nsengekera ya cubic crystal. Ekirungo kyayo eky’eddagala ekimanyiddwa ye LiMn2O4. Mu nsengekera ya kirisitaalo ya LiMn2O4, okisigyeni ali mu nsengekera ya kiyuubi okumpi-erimu ffeesi-centered cubic close-packed structure, ate manganese ne oxygen zikola ensengekera ya octahedral, nga bwe kiragibwa mu kifaananyi wansi.
Manganese mungi mu butonde, era obukodyo bw’okuteekateeka spinel-ekika kya lithium manganese oxide (LiMn2O4) bulaga engeri ez’enjawulo. Ekkubo ly’okusengejja ne tekinologiya w’okulongoosa ekintu kikwata butereevu ku microstructure n’enkula y’empeke y’ekintu ekisembayo. N’olwekyo, okulongoosa enkola zino ez’okusengejja kikulu nnyo mu kulongoosa omulimu gw’amasannyalaze ogw’ebintu eby’obusannyalazo mu nkola ey’omugaso. Mu kiseera kino, amakolero n’abasomesa bakozesa nnyo ebika bibiri ebikulu eby’enkola okuteekateeka LiMn2O4: emu yeesigamiziddwa ku nkolagana wakati w’ebintu ebibisi ebikalu, gamba nga enzirukanya y’embeera enkalu ey’ebbugumu eringi-ensengekera y’embeera, microwave-assisted synthesis, n’okulongoosa okufukirira mu mikutu gy’omunnyo ogusaanuuse.
Ekika ekirala kizingiramu enkyukakyuka y’eddagala mu mbeera y’amazzi, nga waliwo ebyokulabirako ebimanyiddwa omuli tekinologiya wa sol-gel, okusengejja amazzi ag’ebbugumu, n’obukodyo bw’okutonnya awamu. LiMnzO4 efunye okufaayo okunene olw’enkizo yaayo ey’ebbeeyi, okunyweza ebbugumu okulungi, okugumira okusasula okusukkiridde okw’amaanyi, n’emigaso emirungi eri obutonde bw’ensi. Wabula ekintu kino kirina obusobozi bw’okuvuga obugaali n’okutereka naddala ku bbugumu eringi, ng’omutindo gwakyo ogw’okuvuga obugaali gwonooneka nnyo, ekivaako okufiirwa obusobozi obutakyuka.
lithium-erimu manganese omungi-esinziira
Ng’oggyeeko lithium manganese oxide, ebintu ebikolebwa mu layeri lithium-rich manganese-ebisikiriza abantu bangi ng’ekintu kya katodi ekigenda okuvaayo ku bbaatule za lithium-ion.
Enkola z’okuteekateeka ebintu bya katodi ebisinziira ku lithium-rich manganese-mulimu enkola za solid-state, enkola za sol-gel, n’enkola za co-precipitation. Enkola y’embeera enkalu- erimu okutabula butereevu okisayidi z’ebyuma ne kaboni z’ebyuma oba haidrokisayidi z’ebyuma mu kigerageranyo ekigere, ne kigobererwa enkola y’embeera enkalu-ey’ebbugumu eringi-okufuna ebintu ebirimu lithium-ebirimu layeri. Ebirungi ebiri mu nkola ya solid-state bwe busobozi bwayo okusengejja ebintu ebingi ebirimu lithium-ebirimu layeri, enkola yaayo ey’okuteekateeka ennyangu ennyo, n’omuwendo gwayo omutono. Ebizibu bye mugerageranyo omubi ogw’okusaasaana kw’ekintu ekikalu mu kiseera ky’okusiba mu mbeera enkalu-, n’okuba nti ebyuma eby’enjawulo eby’enkyukakyuka birina emiwendo gy’okusaasaana egy’enjawulo mu nsengekera y’embeera enkalu-, ekizibuyiza obutundutundu okusaasaana ekimala. N’olwekyo, obumu bw’ekintu ekisengekeddwa bubi, ekikosa omulimu gw’ekintu kya katodi. Enkola ya sol-gel erimu okusooka okussaamu ekisengejjo ky’omunnyo gw’ekyuma ekikyukakyuka mu kiyungo okukola sol, oluvannyuma n’ofuumuula amazzi okugafuula gel, n’okusembayo okukaza n’okugasiimuula okusobola okufuna ebintu ebingi ebirina layeri za lithium-. Enkola eno evaamu ebintu ebirina ensaasaanya y’emu n’obulongoofu obw’amaanyi, era obusannyalazo obukolebwa bulaga omulimu omulungi ogw’obusannyalazo. Naye ebizibu byayo mulimu enzirukanya y’okukola empanvu, obwetaavu bw’ebiyungo ebingi (asidi ez’obutonde oba ethylene glycol), ekivaamu ssente ennyingi. Ekirala, ebintu ebikoleddwa mu layeri ya lithium-rich ebisinga biba butundutundu bwa nano/micron obulungi nga bulina density entuufu entono. N’olwekyo, enkola eno mu kiseera kino okusinga ekozesebwa mu bifo bya laboratory okukola ebintu ebirimu layeri ya lithium-era era nzibu okubisuubula.
Ebintu ebingi-nickel cathode
Abanoonyereza baludde nga banoonya okutebenkera kw’ebbugumu erya waggulu-n’omutindo omulungi ennyo ng’ebigendererwa ebikulu nga bakola katodi
ebikozesebwa mu bbaatule za lithium-ion. Mu bintu ebikulu ebisatu - LiCoO2, LiNi11₋ᵧCo2MnᵧO2 (NCM), ne LiFePO4 - NCM etwalibwa ng’ekimu ku bintu bya katodi ebisinga okusuubiza olw’obusobozi bwayo obw’enjawulo obw’amaanyi, omuwendo gw’ebintu ebisookerwako obutono, obukuumi obw’ekika ekya waggulu bw’ogeraageranya ne LiCoO2, n’obulungi obulungi okukuuma obutonde bw’ensi n’enkizo ku nsaasaanya ku bintu eby’ennono.
Ekika ky’ekintu kino kirina ensengekera ya kirisitaalo ey’ekika kya -NaFeO2-ekika kye kimu era nga kiri mu kibinja ky’ebbanga ekya R-3m. Endowooza eno yasooka kuteesebwako Liu et al. mu 1999. Mu magezi egatta ebirungi by’ebintu bisatu ebya katodi - lithium cobalt oxide (LiCoO2), lithium nickel oxide (LiNiO2), ne lithium manganese oxide (LiMnO2) - era mu ngeri ennungi eliyirira obusobozi obutono obuli mu buli kintu kinnoomu (nga bwe kiragibwa mu kifaananyi 5-6). Nga tutereeza omugerageranyo gw’ebintu by’ebyuma ebikyukakyuka, bbalansi ennungi wakati w’obusobozi obw’enjawulo, omulimu gw’enzirukanya, obukuumi, n’omuwendo esobola okwongera okutuukibwako.
Ensengekera ya kirisitaalo y’ekintu kya lithium nickel cobalt manganese oxide (NCM) ternary cathode material okusinga y’emu n’eya LiCoO2, zombi za nsengekera ya hexagonal layered.
