Battery cell ke Eng?
Sebopeho sa Lisele
Betri e le 'ngoe, e tsejoang hape e le "sele", ke karolo e nyane ka ho fetisisa ea sistimi ea betri. Haholo-holo e entsoe ka cathode (Cathode Electrode), anode (Anode Electrode), electrolyte (Electrolyte), separator (Separator), le nyeoe (Nyee), joalokaha ho bontšitsoe Figure 7-1.
Letlapa la elektrode la lithium-lisele tsa ion le ka aroloa e le thepa e kopaneng, haholo-holo e nang le likarolo tse nne:
1) Likaroloana tsa lisebelisoa tse sebetsang tse kopanyang kapa tse senyang li-ion tsa lithium; likaroloana tsa cathode li fana ka mohloli oa lithium, ha likaroloana tsa anode li amohela li-ion tsa lithium.
2) Mokhahlelo oa conductive (mohato oa gel ea carbon) o entsoeng ke motsoako oa conductive agent le mokelli oa hona joale, le binder e sebetsang mosebetsi oa ho kopanya; ho roala ho tsamaisa lielektrone ka mokelli oa hona joale le moemeli oa conductive.
3) Maroba a tlatsitsoe ka electrolyte, e sebetsang e le likanale tsa lipalangoang tsa lithium{1}}ka har'a letlapa la eleketrode.
4) 'Mokelli oa hona joale.
Nakong ea ts'ebetso ea electrochemical, ho roala ha elektrode ho kenyelletsa haholo lits'ebetso tse 4 tse latelang:
1) Lipalangoang tsa elektronike.
2) Lipalangoang tsa ion.
3) Phapanyetsano ea tefiso ho sebopeho sa likaroloana tsa electrolyte / electrode, ke hore, karabelo ea electrochemical.
4) Phapang ea li-ion tsa lithium ka har'a mohato o tiileng. Ho sebopeho sa microstructure ea letlapa la eleketrode, boholo ba karoloana le kabo e ama lithium-tsela ea phallo ea ion le sebaka se ikhethileng sa tšebetso ea electrochemical; boholo ba pore le ho ajoa ho ama mokhoa oa ho tsamaisa electrolyte; porosity e ama palo ea lintho tse sebetsang le sebaka se itseng sa karabelo ea electrochemical. Litšobotsi tsena tsohle tsa microstructural qetellong li susumetsa ts'ebetso ea betri.
Sebopeho sa Cathode
The cell cathode haholo-holo e entsoe ka thepa ea cathode e kang LiCoO₂, conductive agent, binder (PVDF), le mokelli oa hona joale (aluminium foil), joalokaha ho bontšitsoe setšoantšong sa 7-2.
Bakeng sa libeteri tsa lithium-ion, pokello ea hajoale ea cathode hangata ke foil ea aluminium 'me pokello ea hona joale ea anode kefoil ea koporo. Ho netefatsa botsitso ba pokello ea hona joale ka hare ho betri, bohloeki ba bobeli bo tlameha ho ba ka holimo ho 98%. Mabaka a etsang hore libeteri tsa lithium-ion li sebelise foil ea aluminium bakeng sa cathode le foil ea koporo bakeng sa anode ke lintlha tse 3 tse latelang:
1) Koporo le aluminium li na le conductivity e ntle ea motlakase, sebopeho se bonolo, le theko e tlase. Molao-motheo oa ts'ebetso oa betri ea lithium{2}}ion ke sesebelisoa sa electrochemical se fetolelang matla a lik'hemik'hale ho matla a motlakase. Ts'ebetsong ena, ho hlokahala seaplane ho fetisetsa matla a lik'hemik'hale ho matla a motlakase, a hlokang thepa e tsamaisang. Har'a lisebelisoa tse tloaelehileng, litšepe li na le motlakase o motle ka ho fetisisa, 'me har'a tšepe, koporo le aluminium li fana ka conductivity e ntle haholo le theko e tlaase ka mokhoa oa foil ea koporo le foil ea aluminium. Libetring tsa lithium-ion, ho na le mekhoa e 'meli ea ho sebetsa: li- winding le stacking. Ha ho bapisoa le stacking, matsoelintsoeke a hloka lipampiri tsa electrode tse sebelisetsoang ho lokisa betri ho ba le phetoho e itseng ho etsa bonnete ba hore lipampiri tsa elektrode ha li fetohe brittle kapa ho senya nakong ea ho phunya. Har'a lisebelisoa tsa tšepe, lifolakha tsa koporo le aluminium li bonolo, li batla li le thata ka koporo / aluminium li theko e boima, likopi tsa koporo le tsa aluminium li batla li le theko e tlaase, 'me mehloli ea koporo le ea aluminium e ngata lefatšeng ka bophara.
2) Lisebelisoa tsa koporo le aluminium le tsona li batla li tsitsitse moeeng. Aluminium e sebetsa habonolo ka lik'hemik'hale le oksijene moeeng ho etsa filimi e teteaneng ea oxide e holim'a metsi, e thibelang ts'ebetso e eketsehileng ea aluminium. Filimi ena ea oxide ea koporo / aluminium e boetse e fana ka phello e itseng ea tšireletso ho aluminium ka electrolyte. Koporo ka boeona e batla e tsitsitse moeeng 'me ha e le hantle ha e kenelle lik'hemik'hale moeeng o omileng.
3) The cathode and anode potentials of lithium-ion libettery li etsa qeto ea hore aluminium foil e sebelisoa bakeng sa cathode le copper foil bakeng sa anode, 'me li ke ke tsa fetoloa. Monyetla oa cathode o phahame, 'me foil ea koporo e na le oxidized habonolo ka matla a phahameng, ha aluminium e na le matla a phahameng a oxidation le filimi e teteaneng ea oxide e holim'a eona, e leng eona e fanang ka tšireletso e ntle bakeng sa aluminium e ka hare.
Ka har'a kristale lattice ea tšepe ea aluminium, koporo le aluminium li na le boholo bo ts'oanang le Li mme li ka theha metsoako ea intermetallic habonolo le Li joalo ka LiAl. Li le Al ha li khone ho theha alloy feela ka foromo ea lik'hemik'hale LiAl, empa li ka boela tsa theha Li₉Al₄, Li₃Al₂, Li₅Al le Li₂Al alloy layers. Li-alloy layers tsena li ja palo e kholo ea Li 'me li senya sebopeho le morphology ea Al ka boeona, kahoo e ke ke ea sebelisoa e le pokello ea hona joale ea anode ea libeteri tsa lithium{2}}ion; ha Cu e senyeha hanyane haholo ha betri e tjha-e ntsha le ho boloka sebopeho le botsitso ba electrochemical, e leng se etsang hore e tshwanelehe ho ba pokello ya jwale ya anode bakeng sa dibetri tsa lithium{4}}ion. Bakeng sa foil ea koporo ho 3.5V, hona joale polarization e qala ho eketseha haholo 'me e phahama ka mokhoa o ts'oanang, e nang le oxidation e matla, e bontšang hore Cu le eona e qala ho qhibiliha ka betri; ha e ntse e le bakeng sa foil ea aluminium ho pholletsa le mefuta eohle e ka bang teng ea polarization, hona joale polarization e nyenyane ebile e tsitsitse, ha ho na liketsahalo tse totobetseng tsa kutu tse hlokometsoeng, ho boloka botsitso ba electrochemical. Kaha chelete ea ho qhibiliha ea Al in cathode e ka bang teng ea libeteri tsa lithium-ion e nyane haholo 'me electrochemical stability e ka lula e tsitsitse, e loketse joalo ka pokello ea hajoale ea cathode bakeng sa libeteri tsa lithium{9}}ion.
Lera la oxide holim'a koporo / aluminium ke la li-semiconductors le ho tsamaisa li-electrone; haeba lera la oxide le teteaneng haholo, impedance e kholo; ha aluminium oxide layer holim'a aluminium e le insulator 'me ha e khone ho tsamaisa motlakase, empa hobane e le tšesaane haholo, conduction ea elektronike e finyelloa ka phello ea tunneling; haeba oxide layer e teteaneng, conductivity ea koporo / aluminium foil e futsanehile kapa e bile e sireletsa. Ka kakaretso, foil ea koporo / aluminium e hloka ho hloekisoa ka lera la oxide pele e sebelisoa ho tlosa oli ka lehlakoreng le leng le likarolo tse teteaneng tsa oxide ho tse ling. Monyetla oa cathode o phahame, 'me lesela la aluminium oxide le teteaneng haholo, le ka thibelang oxidation ea mokelli oa hona joale. Likarolo tsa oxide tsa koporo / nickel joalo-joalo li batla li hlephile, li thibela habonolo mokelli oa hona joale le ho fana ka ts'ebetso e ntle ea betri. Ka nako e ts'oanang, matla a anode a libeteri tsa lithium{5}}a tlase, 'me koporo/nickel e tla kopana le oxidation, ka oxidation/copper/de-lithiation reactions e etsahalang bokaholimo ba koporo/nickel, ha aluminium e sebelisa LiAl alloying ka matla a holimo.
Mokelli oa hona joale o hloka sebopeho se hloekileng. Litšila ho Al li tla etsa hore filimi e ka holimo e fokotsehe 'me e bake kutu ea likoti,' me le ho feta, ho timetsoa ha filimi ea holim'a metsi ho lebisa ho thehoa ha LiAl alloy.
Mokelli oa hona joale o hloka sebopeho se hloekileng. Litšila ho Al li tla etsa hore filimi ea holim'a metsi e se ke ea e-ba le boima bo fokolang, e lebisang ho corrosion ea likoti, 'me ho hobe le ho feta, ho timetsoa ha filimi ea holim'a metsi ho fella ka ho thehoa ha LiAl alloy.
Bakeng sa libeteri tsa lithium-ion, foil ea aluminium ea cathode e fokotsoe ho tloha ho 16μm ho ea ho 14μm, joale ho ea ho 12μm, 'me hona joale 10μm aluminium foil e se e ntse e hlahisoa ka bongata, ba bang ba bile ba sebelisa 8μm; bakeng sa foil ea koporo ea anode, ka lebaka la ho tenyetseha ha eona hantle, botenya ba eona bo fokotsehile ho tloha ho 12μm ho isa ho 10μm, ho ea ho 8μm, 'me hajoale karolo e kholo ea libeteri li boima-li hlahisoa ka 6μm, athe bahlahisi ba bang ba etsa 5μm/4μm tseo le tsona li ka sebetsang. Kaha libeteri tsa lithium{14}}li na le litlhoko tse phahameng tsa ho hloeka bakeng sa foil ea koporo e sebelisitsoeng, boima ba 'mele bo maemong a tšoanang. Ha botenya bo ntseng bo ntlafatsoa bo ntse bo fokotseha, boima ba aalal density boa fokotseha, 'me boima ba betri bo ntse bo ntlafala le ho feta, e leng se khotsofatsang tlhoko ea libeteri tsa lithium{16}}.
Bakeng sa likoleke tsa hajoale, ho kenyelletsa botenya le boima ba tsona bo amang libeteri tsa lithium-ion, boleng ba bokaholimo ba pokello ea hona joale bo na le tšusumetso e kholo tlhahisong le tšebetsong ea betri. Haholo-holo bakeng sa pokello ea hona joale ea anode, ka lebaka la bofokoli ba theknoloji ea ho lokisa, lifola tsa koporo 'marakeng li na le mefuta e le 'ngoe-ea mahlakoreng a mabeli,{3}}e khorofalitsoe ka mahlakoreng a mabeli, le{4}}mefuta e mahoashe ka mahlakoreng a mabeli. Sebopeho sena sa mahlakore a mabeli a asymmetric{6}} se tla lebisa ho hanyetsanang le ho kopana ha asymmetric ka mahlakoreng ka bobeli, ka tsela eo ho thibela ho lokolloa ka mokhoa o ts'oanang oa matla a anode mahlakoreng ka bobeli; Ka nako e ts'oanang, asymmetry mahlakoreng ka bobeli e tla baka matla a sa tsitsang a "anode coating", e leng se tla fella ka ho se leka-lekane ho matla -bophelo ba nako ea ho ntša metsi a anode mahlakoreng ka bobeli, e leng ho potlakisang ho bola ha betri.
Ho etsoa ha cathode ea sele e le 'ngoe ke theknoloji ea mantlha ea sele. Ka tlaase mona ke mohlala:
1)LiCoO₂ (10μm): 96.0%.
2) Moemeli oa conductive (Carbon ECP): 2.0%.
3)Binder (PVDF 761): 2.0%.
4) Adhesion promoter (NMP): Karo-karolelano ea boima ba lintho tse tiileng e ka ba 810:1496.
Litlhokomelo tsa ho etsoa ha cathode:
1) Cathode slurry viscosity control ho 6000cP (1cP=1mPa · s) (mocheso 25℃).
2) Boima ba NMP bo tlameha ho lokisoa ka nepo ho fihlela tlhoko ea viscosity.
3) Ela hloko ka ho khetheha tšusumetso ea mocheso le mongobo ho viscosity.
Lintho tsa cathode lithium cobalt oxide: Lintho tse sebetsang tsa cathode, mohloli oa lithium ion, li fana ka mohloli oa lithium bakeng sa betri. Seo e seng{{1}sebōpeho se sa tloaelehang, boholo ba karoloana ea D50 ka kakaretso ke 6-8μm, mongobo Ka tlase kapa ho lekana le 0.2%, hangata e le alkaline, pH 10-11.
Cathode material lithium manganese oxide: Ha se-ntho e polar, sebopeho se sa tsitsang, boholo ba karoloana D50 hangata ke 5-7μm, mongobo Ka tlase kapa ho lekana le 0.2%, hangata e le alkaline e fokolang, pH e ka bang 8.
Moemeli ea sebetsang: Ketane-joaloka ntho, mongobo<1%, particle size generally 1~5um.Superconductive carbon black with excellent conductivity is usually used, such as KetjenblackCarbon ECP and ECP600JD. lts function is to improve the conductivity of the cathode material,compensate for the electronic conductivity of the cathode active material; increase the electrolyteabsorption of the cathode sheet, expand the reaction interface, and reduce polarization.
Binder (PVDF): E seng{{0}lintho tse polar, ketane-joaloka, boima ba molek'hule ho tloha ho 300000 ho isa ho 3000000; boima ba limolek'hule bo fokotseha ka mor'a ho kenngoa ha metsi, e leng se bakang ho khomarela ho fokolang. E sebelisoa ho tlamahanya lithium cobalt oxide, conductive agent, le foil ea aluminium kapa aluminium mesh togethAdhesion promoter (NMP): Mokelikeli o fokolang oa polar, o sebelisetsoang ho qhibiliha / ho ruruha PVDF le ho hlapolla seretse ka nako e le 'ngoe.
Moqokeleli oa hajoale (tabo ea cathode): E entsoe ka foil ea aluminium kapa strip ea aluminium.
Sebopeho sa Anode
Sebopeho sa anode ea sele se na le lisebelisoa tsa graphite, conductive agent, thickener (CMC), binder (SBR), le mokelli oa hona joale (foil ea koporo), joalokaha ho bontšitsoe setšoantšong sa 7-3.
Ho hlophisoa ha anode ea sele e le 'ngoe hape ke e' ngoe ea litheknoloji tsa mantlha tsa sele, hangata ka tsela e latelang:
1) Lisebelisoa tsa anode (graphite): 94.5%.
2)Moemeli oa conductive (Carbon ECP): 1.0% (Ketjenblack).
3)Binder (styrene-butadiene rabara latex, SBR): 2.25%.
4) Thickener (carboxymethyl cellulose, CMC): 2.25%.
5) Metsi: Karo-karolelano ea boima ba lintho tse tiileng ke 1600: 1417.5.
Litlhokomelo tsa tlhahiso ea anode:
1)Anode slurry viscosity taolo ho 5000-6000cP (mocheso 25 degree).
2) Boima ba metsi bo hloka ho lokisoa ka nepo ho fihlela tlhokahalo ea viscosity.
3) Ela hloko ka ho khetheha tšusumetso ea mocheso le mongobo ho viscosity.
Graphite: Lintho tse sebetsang tsa anode, ntho e ka sehloohong e etsang karabelo ea anode, e arotsoe haholo ka mekhahlelo e 'meli e meholo: graphite ea tlhaho le graphite ea maiketsetso. E seng{{1}lintho tse nang le polar, tse silafalitsoeng ha bonolo ke-lintho tse sa polar, tse qhalakantsoeng ha bonolo ho-lintho tseo e seng tsa polar; ha ho bonolo ho monya metsi, leha e le ho hasana habonolo ka metsing. graphite e silafetseng, ka mor'a hore e qhalakane ka metsing, e atisa ho-agglomerate. Kakaretso ea boholo ba karoloana D50 e ka ba 20μm. Libopeho tsa likaroloana li fapane 'me hangata ha li tloaelehe, haholo-holo li chitja, li matheba, li na le fiber, joalo-joalo.
Mesebetsi ea conductive agent:
1) Ntlafatsa mokhoa oa ho tsamaisa lakane ea anode le ho lefella conductivity ea elektroniki ea lisebelisoa tse sebetsang tsa anode.
2) Eketsa botebo ba karabelo le sekhahla sa ts'ebeliso.
3) Thibela moloko oa dendrites.
4) Sebelisa mokelikeli-mokhoa oa ho monya oa thepa ea conductive ho eketsa sebopeho sa karabelo le ho fokotsa polarization (e ka eketsoa kapa che ho latela kabo ea boholo ba graphite).
Li-additives: Fokotsa ts'ebetso e ke keng ea etsolloa, eketsa matla a tlamahano le viscosity e hlephileng, 'me u thibele ho senyeha ha seretse.
Thickener/anti{0}}settling agent (CMC): Motsoako o phahameng oa molek'hule, o qhibiliha ha bonolo metsing le lihlapolli tsa polar.
Isopropanol: Ntho e fokolang ea polar; ka mor'a ho phaella moo, e ka fokotsa polarity ea tharollo ea binder, ea ntlafatsa ho lumellana pakeng tsa tharollo ea graphite le binder; e na le phello e matla ea defoaming; ha bonolo e etsa hore ho be bonolo-ho hokahana ha marangrang a binder le ho ntlafatsa matla a tlamahano.
Ethanol: Ntho e fokolang ea polar; ka mor'a ho phaella moo, e ka fokotsa polarity ea tharollo ea binder, ea ntlafatsa ho lumellana pakeng tsa tharollo ea graphite le binder; e na le phello e matla ea defoaming; e thusa habonolo linear cross-ho hokahana ha binder le ho ntlafatsa matla a tlamahano (mesebetsi ea isopropanol le ethanol ha e le hantle e ea tšoana; ha boima- bo hlahisoa, lintlha tsa litšenyehelo li ka nahanoa ho khetha hore na u tla eketsa efe).
Metsi-e kopanyang setlamo sa metsi (SBR): Likopano tsa graphite, conductive agent, additives, le foil ea koporo kapa mesh ea koporo hammoho; Molek'hule ea emulsion ea linear, e qhibilihang ka ho fetesisa metsing le li-solvents tsa polar.
Metsi a hloekisitsoeng (kapa metsi a hloekisitsoeng): Diluent, e kentsoeng ka tekanyo e nepahetseng, e ka fetola metsi a slurry.
Anode tab: E entsoe ka foil ea koporo kapa khoele ea koporo.
