Thepa ea cathode ke mohloli o ka sehloohong oa li-ion tsa lithium kalithium{0}}betri ea ion. Nakong ea ho tjhaja, li-ion tsa lithium li ntšoa ka lesela la kristale la cathode ebe li kenya lisebelisoa tsa anode; se fapaneng se etsahala nakong ea ho tsoa. Bokhoni bo ka khutlisoang morao le sebaka sa motlakase sa cathode nakong ea ho tjhaja le ha ho chafatsoa, haholo-holo, ho laola boholo ba matla a betri ea lithium{2}}abone. Ho feta moo, kaha thepa ea cathode e na le tšepe e kang lithium, cobalt, nickel, e etsa karolo ea bohlokoa ka ho fetisisa ea theko ea betri ea lithium{4}}ion.
Ho nts'etsapele lisebelisoa tsa cathode tse nang le matla a phahameng a matla, matla a phahameng a tsoang, bophelo bo bolelele ba ts'ebeletso le boiketlo ba ho qapa ho bohlokoa haholo. Lintho tse ntle tsa cathode li lokela ho finyella maemo a latelang a motheo.
(1) E na le matla a phahameng a redox, e netefatsang matla a phahameng a tlhahiso bakeng sa betri.
(2) E ka amohela li-ion tsa lithium tse ngata kamoo ho ka khonehang, e netefatsa hore betri e na le matla a holimo.
(3) Nakong ea ho kenngoa le ho ntšoa ha lithium ion, thepa ea cathode e ka boloka botsitso ba eona ba sebopeho, kahoo e tiisa bophelo ba nako e telele bakeng sa electrode.
(4) E na le conductivity e ntle ea elektroniki le ion, e fokotsang tahlehelo ea matla e bakoang ke litlamorao tsa polarization, ka hona e netefatsa hore betri e tjhaja ka potlako le bokhoni ba ho lahla.
(5) Matla a ho sebetsa a betri a lokela ho ba ka har'a sebaka sa botsitso ba electrochemical ea electrolyte, ka ho etsa joalo e fokotse karabelo e sa hlokahaleng ea lik'hemik'hale lipakeng tsa lisebelisoa tsa eleketrode le electrolyte.
(6) Ha ea lokela ho ba le litšenyehelo tse tlaase feela le mokhoa o bonolo oa ho kopanya, empa hape e lokela ho bontša botsoalle bo phahameng ba tikoloho.
Ho feta moo, thepa ea cathode e lokela ho bonts'a botsitso bo botle ba electrochemical le mocheso.
Lisebelisoa tse teng tsa cathode li ka aroloa haholo ka mekhahlelo e meraro ho latela phapang ea sebopeho sa kristale: ① sebopeho sa layered, joalo ka lithium cobalt oxide (LiCoO2) le lisebelisoa tsa ternary (LiNiCo, Mni-x-yO2); ② sebopeho sa olivine, joalo ka lithium iron phosphate (LiFePO4); ③ spinel structure oxides, tse kang lithium manganese oxide (LiMn2O4) le lithium nickel manganese oxide (LiNi10.5Mn1.5O4). Mefuta e fapaneng ea li-cathode e na le matla a fapaneng a matla, litšoaneleho tsa electrochemical le litšenyehelo, qetellong li etsa hore li tšoanelehe bakeng sa masimo a fapaneng le maemo a ts'ebeliso. Lisebelisoa tsa cathode tse entsoeng ka lera li bua ka lisebelisoa tsa cathode tse nang le sebopeho sa microcrystalline, haholo-holo ho kenyelletsa lithium cobalt oxide, lithium nickel cobalt manganese oxide, le lithium{12}manganese oxide e ruileng. Har'a tsona, lithium cobalt oxide le lithium nickel cobalt manganese oxide hajoale ke lisebelisoa tse sebelisoang haholo tsa cathode bakeng sa libeteri tsa lithium{14}}lihlahisoa tsa elektroniki tsa dijithale le libeteri tsa matla tsa lithium{15}}ion. Li khetholloa ka matla a mangata a matla, ts'ebetso e ntle ea potoloho, le ts'ebetso e ntle ka kakaretso, empa karolo e phahameng ea tšepe e kang nickel, cobalt le manganese e lebisa litšenyehelong tse phahameng.
Lithium cobalt oxide cathode lintho tse bonahalang
Lithium cobalt oxide (LiCoO2) e ile ea sibolloa ke rasaense oa Moamerika le mohapi oa Nobel ho Chemistry, JB Goodenough, mme ea qala ho rekisoa ke Sony Corporation ea Japane ka bo-1990. Le kajeno, lithium cobalt oxide e ntse e le e 'ngoe ea lisebelisoa tsa cathode tse nang le matla a phahameng ka ho fetisisa a matla. Ka lebaka lena, e sebelisoa haholo lihlahisoa tsa selefouno tsa dijithale tse hlokang matla a phahameng a molumo, joalo ka mehala ea cellular, li-smartwatches, le li-headsets tsa 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). Ho feta moo, LiCoO2 e bonts'a tšebetso e batlang e phahame ea elektroniki le ea ionic, ts'ebeliso e ntle ea matla, le litšobotsi tsa ho tjhaja-ka potlako, e fihlelang litlhoko tsa libeteri tsa hajoale tsa lisebelisoa tsa elektroniki, kahoo e na le mefuta e mengata ea lits'ebeliso. E ipapisitse le thepa ena, LiCoO2 e ntse e le e 'ngoe ea lisebelisoa tse ntle ka ho fetisisa tsa cathode ho fihlela joale.
Mekhoa ea mantlha ea ho kopanya lithium cobalt oxide e kenyelletsa-mocheso o tiileng-state synthesis, sol-gel synthesis, le{3}}tlaase coprecipitation. Mocheso o phahameng-o tiileng{6}}motsoako oa naha o kopanyelletsa ho kopanya letsoai la lithium le cobalt{7}}e nang le oxides kapa hydroxides ka tekanyo e itseng ea stoichiometric, ebe ho calcining motsoako ka mocheso o loketseng ka nako e itseng, ho lateloe ke ho pholisa, ho phunya, le ho sefa ho fumana sampole. Le hoja mokhoa o phahameng-mokhoa o tiileng{10} o sebelisoang haholo tlhahisong ea liindasteri, o ja nako{11}}o hloka nako, o hloka lithempereichara tse phahameng, 'me o hlahisa phofo e kholo, e sa leka-lekaneng e nang le liphapang tse kholo tsa stoichiometric, e leng se bakang keketseho e kholo ea theko.
Lisebelisoa tsa cathode tsa phosphate
Ka 1997, Goodenough et al. pele ho sisintsweng lithium iron phosphate (LiFePO4) e le sesebediswa sa cathode bakeng sa dibetri tsa lithium-ion.
Ka lebaka la theko ea eona e tlase, sebopeho se tsitsitseng, le polokeho e phahameng, thepa ena butle-butle e fetohile e 'ngoe ea lisebelisoa tsa cathode tse ratoang bakeng sa libeteri tsa lithium-ion libese tsa motlakase le mekhoa ea ho boloka matla.
Lithium iron phosphate (LiFePO4) e arolelana sebopeho se tšoanang sa kristale le tsamaiso ea kristale e nang le tšepe ea phosphate (FePO4). Sena se bolela hore thepa e na le phetoho e fokolang ea molumo nakong ea lithium-ea ho kenya/ho ntša, ho thibela ka katleho tšenyo e bakoang ke ho atolosoa ha molumo kapa ho honyela. Ho feta moo, tšobotsi ena e tiisa kamano e ntle ea motlakase pakeng tsa likaroloana le li-additives tsa conductive, tse hlahisang botsitso bo botle ba potoloho le nako e telele ea bophelo. Ho feta moo, lithium iron phosphate e tumme ka ho baballa tikoloho, litšenyehelo- tse sebetsang hantle, polokeho e babatsehang, matla a khethehileng a holimo (hoo e ka bang 170 mA·h/g), le sethala se tsitsitseng sa tefiso/ho ntša metsi. Ka lebaka la melemo ena, lithium iron phosphate e nkuoa e le khetho e nepahetseng bakeng sa lisebelisoa tsa cathode libakeng tse kholo{9}} tsa polokelo ea matla.
Mekhoa ena e kenyelletsa -mekhoa ea sol, mekhoa ea ho kopanya, le hydrothermal synthesis. Haholo-holo, motsoako oa hydrothermal o hlahisa sehlahisoa se lebisitsoeng ka ho toba ho autoclave ka ho eketsa mocheso le khatello, ho sebelisa metsoako ea tšepe, lithium le phosphorus tse fumanehang habonolo e le lisebelisoa tse tala. Mokhoa ona o tsebahala ka ts'ebetso ea ona e bonolo, boholo ba likaroloana tse nyane le tse ts'oanang, le tšebeliso e tlase ea matla. Leha ho le joalo, e na le meeli bakeng sa tlhahiso ea indasteri, haholo-holo ka lebaka la tlhoko ea likhatello tse entsoeng ka mokhoa o ikhethileng{4}} Coprecipitation, ka lehlakoreng le leng, e etsoa ka mokhoa oa tharollo, moo morpholoji ea pele e amehang ke lintlha tse sa tšoaneng tse kang ho tsepamisa mohopolo, ho laola mocheso, ho fetola pH, le sekhahla se susumetsang. Ha ho nahanoa ka karolo ea makhaola-khang e bapaloang ke likarolo tsena ts'ebetsong ea lisebelisoa tsa ho qetela tsa LiFePO, khetho e hlokolosi ea maemo a liteko ke ea bohlokoa. Lihlahisoa tse lokiselitsoeng ka mokhoa ona ha li na feela litšobotsi tse ntle tsa microstructure (ke hore, boholo ba likaroloana tse nyenyane le tse lekanang) empa hape li bontša litšobotsi tse phahameng tsa electrochemical; leha ho le joalo, ke habohlokoa ho hlokomela hore ts'ebetso eohle ea ts'ebetso e batla e rarahane, 'me mathata a ho hloekisa le mathata a tsamaiso ea litšila a ka hlaha nakong ea ts'ebetso.
Lithium manganese oxide le lithium-manganese e ruileng{1}thepa ea cathode
Lithium manganese oxide
Lipatlisisong tsa lithium{0}}ion battery cathode material, e 'ngoe ea bohlokoa le e fumanehang khoebong ea cathode ke spinel{1}}structured lithium manganese oxide (LiMn₂O₄) cathode material e sisintsweng ke Thackeray et al. ka 1983. Spinel{4}}structured lithium manganese oxide ke karolo ea cubic crystal system. Sebopeho sa eona se tloaelehileng sa lik'hemik'hale ke LiMn₂O₄. Ka har'a sebopeho sa kristale sa LiMn₂O₄, oksijene e ka har'a sefahleho{7}}ka sebopeho se bohareng sa cubic{8}e pakileng, ha manganese le oksijene li etsa sebopeho sa octahedral, joalo ka ha ho bonts'itsoe setšoantšong se ka tlase.
Manganese e ngata ka tlhaho, 'me mekhoa ea ho lokisa bakeng sa spinel-mofuta oa lithium manganese oxide (LiMn2O4) e bontša litšobotsi tse fapaneng. Tsela ea ho kopanya le theknoloji ea ts'ebetso ea thepa e ama ka ho toba microstructure le nts'etsopele ea lijo-thollo tsa sehlahisoa sa ho qetela. Ka hona, ho ntlafatsa ts'ebetso ena ea ho kopanya ho bohlokoa bakeng sa ho ntlafatsa ts'ebetso ea electrochemical ea lisebelisoa tsa elektrode lits'ebetsong tse sebetsang. Hajoale, indasteri le barutehi ba sebelisa mefuta e 'meli ea mantlha ea ho lokisa LiMn2O4: e 'ngoe e ipapisitse le tšebelisano lipakeng tsa lisebelisoa tse tiileng, joalo ka -mocheso o tiileng{9}}ka boemo bo phahameng, motsoako oa microwave{10}} le kalafo ea ho kenngoe mecheng ea letsoai e qhibilihisitsoeng.
Mokhahlelo o mong o kenyelletsa phetoho ea lik'hemik'hale tikolohong ea mokelikeli, ka mehlala e tloaelehileng e kenyeletsang theknoloji ea sol-gel, hydrothermal synthesis, le mekhoa ea coprecipitation. LiMnzO4 e hohetse tlhokomelo e atileng ka lebaka la molemo oa theko ea eona, botsitso bo botle ba mocheso, khanyetso e matla ea tefiso, le melemo e metle ea tikoloho. Leha ho le joalo, thepa ena e na le mefokolo ts'ebetsong ea libaesekele le polokelo, haholo-holo mocheso o phahameng, moo ts'ebetso ea eona ea libaesekele e senyehang haholo, e lebisang ho tahlehelo e ke keng ea fetoloa ea bokhoni.
lithium-manganese e ruileng{{1}e thehiloeng
Ntle le lithium manganese oxide, lithium{0}e nang le manganese e ngata{1}e khahlileng batho ba bangata joalo ka lisebelisoa tse hlahang tsa cathode bakeng sa libeteri tsa lithium{2}}ion.
Mekhoa ea boitokisetso ea lithium-manganese e humileng{1}lisebelisoa tse thehiloeng ho cathode li kenyelletsa lintho tse tiileng-mekhoa ea boemo, -mekhoa ea gel, le mekhoa ea-ea pula. Mokgwa o tiileng{{6}o akarelletsa ho kopanya metal oxides le metal carbonates kapa metal hydroxides ka tekanyo e itseng, mme ho latelwe{7}}thempereichara e tiileng{8}ya boemo bo hodimo ho fumana disebediswa tse nonneng tsa lithium{9}. Melemo ea{11}}mokhoa oa boemo bo tiileng ke bokhoni ba eona ba ho kopanya bongata bo boholo ba lisebelisoa tse nonneng tsa lithium{12}, mokhoa oa eona o bonolo oa ho lokisa, le theko ea eona e tlase. Litšitiso ke ho fokola ha coefficient ea solidi nakong ea solid{14}}state sintering, le taba ea hore li-transition metal tse fapaneng li na le maemo a fapaneng a pharalletseng ho solid{15}}state reaction, e leng ho etsang hore ho be thata hore likaroloana li hasane ka ho lekaneng. Ka hona, ho ts'oana ha lintho tse entsoeng ka maiketsetso ha li na thuso, tse amang ts'ebetso ea lisebelisoa tsa cathode. Mokgwa wa sol-gel o kenyelletsa ho qala ka ho kenya motsoako wa letswai la letswai ho kopanyo ho etsa sol, ebe o etsa mouwane wa metsi ho a etsa gel, mme qetellong o a omise le ho a etsa calcining ho fumana disebediswa tse nonneng tsa lithium{19}. Mokhoa ona o fana ka lisebelisoa tse nang le kabo e tšoanang le bohloeki bo phahameng, 'me li-electrode tse hlahisoang li bontša ts'ebetso e ntle ea electrochemical. Leha ho le joalo, litšitiso tsa eona li kenyelletsa potoloho e telele ea masela, tlhokahalo ea li-integrator tse ngata (organic acid kapa ethylene glycol), e bakang litšenyehelo tse phahameng. Ho feta moo, lisebelisoa tse entsoeng ka lesela la lithium{23}ke boholo ba likaroloana tsa nano/micron tse fokolang haholo. Ka hona, mokhoa ona ha joale o sebelisoa haholo-holo litlhophisong tsa laboratoring bakeng sa ho etsa lisebelisoa tse nonneng tsa lithium{25}'me ho thata ho li etsa khoebong.
-lisebelisoa tse phahameng tsa nickel cathode
Haesale bafuputsi ba batla ho tsitsisa{0}thempereicha e phahameng le ts'ebetso e ntle haholo e le sepheo sa mantlha ha ho etsoa cathode.
lisebelisoa tsa libeteri tsa lithium{0}}ion. Har'a lisebelisoa tse tharo tse kholo - LiCoO₂, LiNi₁ₓ₋ᵧCoₓMnᵧO₂ (NCM), le LiFePO₄ - NCM e nkoa e le e 'ngoe ea lisebelisoa tse tšepisang ka ho fetisisa tsa cathode ka lebaka la bokhoni ba eona bo itseng bo phahameng, litšenyehelo tse tlaase tsa thepa e tala, molemo o moholo oa tšireletso ea tikoloho, Litšenyehelo tse phahameng tsa tlhaho le ts'ireletseho ea ColiO. lisebelisoa.
Mofuta ona oa thepa o na le mofuta o tšoanang oa -NaFeO₂-mofuta oa kristale oa layered sebopeho 'me ke oa sehlopha sa R{6}}3m sa sebaka. Khopolo ena e ile ea hlahisoa pele ke Liu et al. ka 1999. E kopanya ka bohlale melemo ea lisebelisoa tse tharo tsa cathode - lithium cobalt oxide (LiCoO₂), lithium nickel oxide (LiNiO₂), le lithium manganese oxide (LiMnO₂) - 'me ka katleho e lefella mefokolo e teng ho boitsebiso bo bong le bo bong (5-6). Ka ho lokisa karo-karolelano ea likarolo tsa tšepe tsa phetoho, tekanyo e nepahetseng har'a bokhoni bo itseng, ts'ebetso ea potoloho, polokeho le litšenyehelo li ka finyelloa ka ho eketsehileng.
Sebopeho sa kristale sa lithium nickel cobalt manganese oxide (NCM) ternary cathode material ha e le hantle se ts'oana le sa LiCoO2, ka bobeli ke tsa sebopeho sa hexagonal layered.
