Chii chinonzi Battery cell?
Sero Maumbirwo
Bhatiri rimwechete, rinozivikanwawo se "sero", ndiro diki diki rebhatiri system. Inonyanya kuumbwa ne cathode (Cathode Electrode), anode (Anode Electrode), electrolyte (Electrolyte), separator (Separator), uye nyaya (Nyaya), sezvinoratidzwa mumufananidzo 7-1.
Pepa re electrode re lithium-ion cell rinogona kuiswa muchikamu sechinhu chakaumbwa, kunyanya chinosanganisira zvikamu zvina:
1) Active zvinhu zvimedu zvinopindirana kana deintercalate lithium ions; cathode particles inopa iyo lithium sosi, nepo anode particles anogamuchira lithium ions.
2)Iyo conductive phase (carbon gel phase) yakaumbwa nemusanganiswa we conductive agent uye ikozvino muunganidzi, ine binder inoshanda basa rekubatanidza; iyo yekupfekedza inoitisa maerekitironi kuburikidza neazvino muunganidzi uye conductive agent.
3)Maburi anozadzwa neelectrolyte, ayo anoshanda sematanho ekutakura lithium-ion mukati mepepa re electrode.
4) Iye zvino muunganidzi.
Munguva ye electrochemical process, iyo electrode coating inonyanya kusanganisira 4 maitiro anotevera:
1)Kutakurwa kwemagetsi.
2)Ion kutakura.
3) Charge exchange at the electrolyte/electrode particle interface, kureva, iyo electrochemical reaction.
4) Kupararira kwe lithium ions mukati mechikamu chakasimba. Mune microstructure ye electrode sheet, particle size uye kugovera kunobata lithium-ion diffusion nzira uye nzvimbo chaiyo ye electrochemical reaction; pore saizi uye kugovera kunokanganisa nzira yekufambisa ye electrolyte; porosity inokanganisa huwandu hwezvinhu zvinoshanda uye iyo chaiyo nzvimbo ye electrochemical reaction. Ese aya ma microstructural maitiro anozopesvedzera kuita kwebhatiri.
Cathode Structure
Iyo sero cathode inonyanya kuumbwa nezvinhu zvecathode seLiCoO₂, conductive agent, binder (PVDF), uye iye zvino muunganidzi (aluminium foil), sezvinoratidzwa mumufananidzo 7-2.
Kumabhatiri e lithium-ion, cathode current collector inowanzova aluminium foil uye anode current collectorfoil yemhangura. Kuti uone kugadzikana kwemuunganidzi aripo mukati mebhatiri, kuchena kwezvose zviri zviviri kunofanira kunge kuri pamusoro pe98%. Zvikonzero zvinoita kuti mabhatiri e lithium-ion ashandise foiri yealuminium kufoiri yecathode necopper foil yeanode ndezvipoinzi zvitatu zvinotevera:
1) Copper nealuminium zvine yakanaka conductivity yemagetsi, yakapfava magadzirirwo, uye yakaderera mutengo. Mashandiro ebhatiri relithium-ion is electrochemical device inoshandura simba remakemikari kuita simba remagetsi. Mukuita uku, svikiro inodiwa kuendesa simba remakemikari musimba remagetsi, iro rinoda conductive material. Pakati pezvinhu zvakajairika, simbi dzine akanakisa emagetsi conductivity, uye pakati pesimbi, mhangura nealuminium zvinopa zvese zvakanakisa conductivity uye mutengo wakaderera muchimiro chemhangura foil uye aluminium foil. Mumabhatiri e lithium-ion, pane nzira mbiri dzekugadzirisa: kumonereka nekuturikidzana. Kuenzaniswa nekuturikidzana, kupeta kunoda masheti e electrode anoshandiswa kugadzirira bhatiri kuti ive neimwe shanduko kuti ive nechokwadi chekuti mashizha e electrode haaite brittle kana kuputsika panguva yemhepo. Pakati pezvinhu zvesimbi, mapepi emhangura nealuminium akapfava, akaomarara emhangura/aruminiyamu mafoiri anodhura, mhangura nealuminium foil zvakachipa, uye zviwanikwa zvemhangura nealuminium zvakawandisa pasi rose.
2) Copper nealuminium foils zvakare yakagadzikana mumhepo. Aluminium inopindirana nekemikari zviri nyore pamwe neokisijeni mumhepo kuti igadzire dense oxide firimu pamusoro, kudzivirira kumwe kuita kwealuminium. Iyi oxide firimu yemhangura / aluminium inopawo imwe yekudzivirira maitiro paaluminium mu electrolyte. Mhangura pachayo inodzikama mumhepo uye haina kuita zvemakemikari mumhepo yakaoma.
3)Cathode uye anode zvinogoneka zvelithium-mabhatiri eion anoona kuti foil yealuminium inoshandiswa pacathode necopper foil yeanode, uye haikwanise kuchinjwa. Iyo cathode inogoneka yakakwirira, uye foil yemhangura inonyoreswa nyore nyore pakukwanisa kwepamusoro, nepo aluminium ine yakakwirira oxidation inogona uye dense oxide firimu pamusoro wayo layer, iyo inopawo kudzivirira kwakanaka kwearuminiyamu yemukati.
Mune crystal lattice yesimbi yealuminium, mhangura nealuminium zvine saizi yakafanana neLi uye inogona kuumba zviri nyore intermetallic compounds neLi seLiAl. Li naAl havangogone kuumba alloy nemakemikari formula LiAl, asi vanogonawo kugadzira Li₉Al₄, Li₃Al₂, Li₅Al uye Li₂Al alloy layers. Aya alloy layers anodya yakawanda yeLi uye anokuvadza chimiro uye morphology yeAl pachayo, saka haigone kushandiswa seanode ikozvino muunganidzi we lithium-ion mabhatiri; uku Cu ichiparara zvishoma panguva yekuchaja bhatiri-kubuda uye kuchengetedza chimiro uye electrochemical kugadzikana, zvichiita kuti ikwane seanode inounganidza mabhatiri e lithium-ion. Kune foil yemhangura pa 3.5V, iyo polarization ikozvino inotanga kuwedzera zvakanyanya uye inokwira mutsara, nekuwedzera oxidation, zvichiratidza kuti Cu zvakare inotanga kunyungudika mubhatiri; nepo kune aruminiyamu foil mhiri kwese kwepolarization inogona siyana, iyo polarization ikozvino idiki uye yakagadzikana, isina pachena corrosion phenomena inocherechedzwa, kuchengetedza electrochemical kugadzikana. Sezvo huwandu hwekunyungudika kweAl mu cathode inogona siyana yelithium-mabhatiri eion idiki zvakanyanya uye kugadzikana kwe electrochemical kunogona kuchengetedzwa, yakakodzera secathode inounganidza mabhatiri e lithium-ion.
Iyo oxide layer pamhangura/aluminum inotarisana ndeye semiconductors uye inoitisa maerekitironi; kana iyo oxide layer yakanyanyisa, iyo impedance yakakura; nepo aluminium oxide layer iri pamusoro pealuminium insulator uye haigone kuitisa magetsi, asi nekuti yakanyanya kutetepa, electron conduction inowanikwa kuburikidza nekuita tunneling; kana iyo oxide layer yakakora, conductivity yemhangura / aluminium foil haina kunaka kana kutodzivirira. Kazhinji, mhangura / aluminium foil inoda kucheneswa kweiyo oxide layer isati yashandiswa kubvisa mafuta kune rimwe ruoko uye gobvu oxide layer kune rimwe. Iyo cathode inogoneka yakakwira, uye iyo aluminium oxide layer yakanyanya kusimba, iyo inogona kudzivirira oxidation yemuunganidzi aripo. Oxide layers yemhangura/nickel etc. yakasununguka, inodzivirira zviri nyore muunganidzi aripo uye inopa kuita kurinani kwebhatiri. Panguva imwecheteyo, anode inode yelithium-mabhatiri eion yakaderera, uye mhangura/nickel ichaita oxidation reactions, ine oxidation/copper/de-lithiation reactions inoitika pamhangura/nickel surface, ukuwo aruminiyamu ichiita LiAl alloying pakukwanisa kukuru.
Ikozvino muunganidzi inoda kuumbwa kwakachena. Kusvibiswa muAl kuchaita kuti firimu repamusoro rive shoma uye rinokonzera gomba gorosi, uye kunyanya zvakanyanya, kuparadzwa kwefirimu yepamusoro kunotungamirira pakuumbwa kweLiAl alloy.
Ikozvino muunganidzi inoda kuumbwa kwakachena. Kusachena muAl kuchaita kuti firimu repamusoro rive shoma, zvichiita kuti gomba rive nekuora, uye zvakatonyanya kuipa, kuparadzwa kwemufirimu wepamusoro kunokonzera kuumbwa kweLiAl alloy.
Kumabhatiri e lithium-ion, cathode aluminium foil yakaderedzwa kubva pa16μm kusvika 14μm, ikazosvika pa12μm, uye iko zvino 10μm aruminiyamu foil yatova mukugadzirwa kukuru, vamwe vachitoshandisa 8μm; yeanode copper foil, nekuda kwekushanduka kwayo zviri nani, ukobvu hwayo hwadzikiswa kubva pa12μm kusvika 10μm, kusvika pa8μm, uye parizvino chikamu chikuru chemabhatiri ane huremu-achigadzirwa achishandisa 6μm, ukuwo vamwe vanogadzira vari kugadzira 5μm/4μm ayo anogona kushandiswa zvakare. Sezvo lithium-mabhatiri eion ane hutsanana hwakanyanya hunodiwa pafoiri yemhangura inoshandiswa, hunyoro hwematerial huri padanho rimwe chete. Sezvo kukora kuri kuita kuderera, kuremerwa kwebhatiri kunodzikira zvinoenderana, uye huremu hwebhatiri hunoita hureruke nekureruka, izvo zvinoenderana nezvinodiwa zvemabhatiri elithium{16}}.
Kune vaunganidzi vemazuva ano, pamusoro pekukora uye huremu hwavo hunokanganisa mabhatiri e-lithium-iyoni, zvimiro zvemuunganidzi wazvino zvine simba guru pakugadzira nekushanda kwebhatiri. Kunyanya yeanode inounganidza ikozvino, nekuda kwekukanganisa mukugadzira tekinoroji, mafoil emhangura pamusika anonyanya kuenzana-ane mativi akaomarara, akaomeswa kaviri-pamativi akaomeswa, uye{4}}mativi akakoshwa kaviri. Iyi asymmetric two-yakatarisana chimiro ichaita kuti asymmetric contact resistance yeanode coating kumativi ose, nokudaro kudzivirira kusunungurwa kweyunifomu yeanode simba kumativi ose maviri; panguva imwecheteyo, iyo asymmetry kumativi ese ichaitawo kusaenderana kusimba kwekunamatira kweanode coating, zvichikonzera kusaenzana kwakanyanya kuchaji-kuburitsa hupenyu hweiyo anode coating kumativi ese, izvo zvinozoita kuti kukurumidza kuora kwebhatiri.
Iyo cathode kuumbwa kwesero rimwe chete ndiyo yakakosha tekinoroji yesero. Pazasi pane muenzaniso:
1)LiCoO₂ (10μm): 96.0%.
2) Conductive agent (Carbon ECP): 2.0%.
3)Binder (PVDF 761): 2.0%.
4) Adhesion kukurudzira (NMP): Huremu hwehuremu hwezvinhu zvakasimba hunosvika 810:1496.
Cathode maitiro ekudzivirira:
1) Cathode slurry viscosity control pa 6000cP (1cP=1 mPa · s) (tembiricha 25 degree).
2) Huremu hweNMP hunofanirwa kugadziridzwa nenzira kwayo kuti isangane nezvinodiwa viscosity.
3) Nyatsoteerera kune pesvedzero yekushisa uye humidity pane viscosity.
Cathode zvinhu lithium cobalt oxide: Cathode inoshanda zvinhu, lithium ion sosi, inopa lithium sosi yebhatiri. Zvisiri{{1}zvinhu zvepolar, chimiro chisina kujairika, saizi yechidimbu D50 kazhinji 6-8μm, mwando Zvishoma pane kana kuenzana ne0.2%, kazhinji alkaline, pH 10-11.
Cathode material lithium manganese oxide: Isiri-polar substance, irregular shape, particle size D50 generally 5-7μm, mwando Zviri pasi kana kuenzana ne0.2%, kazhinji isina simba alkaline, pH inenge 8.
Conductive agent: Chain-sechinhu, mwando<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): Zvisiri-zvinhu zvepolar, cheni-se, uremu hwemorekuru hunotangira pa300000 kusvika pa3000000; molecular uremu inodzikira mushure mekutora mvura, zvichikonzera kunamatira kwakashata. Inoshandiswa kubatanidza lithium cobalt oxide, conductive agent, nealuminium foil kana aluminium mesh togetherAdhesion promotioner (NMP): Mvura yepa polar isina simba, inoshandiswa kunyungudutsa / kuzvimba PVDF uye panguva imwe chete kunyungudutsa slurry.
Iye zvino muunganidzi (cathode tab): Yakagadzirwa nealuminium foil kana aluminium strip.
Anode Structure
Sero anode chimiro chine graphite zvinhu, conductive agent, thickener (CMC), binder (SBR), uye iyezvino muunganidzi (copper foil), sezvakaratidzwa muFigure 7-3.
Iyo anode kugadzirwa kwesero rimwe zvakare imwe yeakakosha tekinoroji yesero, kazhinji seinotevera:
1) Anode zvinhu (graphite): 94.5%.
2)Conductive agent (Carbon ECP): 1.0% (Ketjenblack).
3)Binder (styrene-butadiene rubber latex, SBR): 2.25%.
4) Thickener (carboxymethyl cellulose, CMC): 2.25%.
5) Mvura: Huremu hwehuremu hwezvinhu zvakasimba ndeye 1600: 1417.5.
Anode maitiro ekudzivirira:
1) Anode slurry viscosity control pa5000-6000cP (tembiricha 25 degree).
2) Huremu hwemvura hunoda kugadziridzwa nenzira kwayo kuti isangane nechinodiwa che viscosity.
3) Nyatsoteerera kune pesvedzero yekushisa uye humidity pane viscosity.
Graphite: Anode inoshanda zvinhu, chinhu chikuru chinoumba anode reaction, inonyanya kukamurwa kuita mapoka maviri makuru: girafu yechisikigo uye yekugadzira graphite. Zvisiri{{1}polar substance, zviri nyore kusvibiswa nezvinhu-zvisiri polar, zvinoparadzirwa zviri nyore mune-zvinhu zvisiri polar; kwete nyore kusveta mvura, kana nyore kupararira mumvura. graphite yakasvibiswa, mushure mekuparadzirwa mumvura, inowanzoita zvakare-agglomerate. Iyo yakawanda particle size D50 inenge 20μm. Maumbirwo emhando dzakasiyana uye kazhinji haana kurongeka, kunyanya spherical, flaky, fibrous, nezvimwe.
Mabasa e conductive agent:
1) Kuvandudza mafambisirwo eanode sheet uye kutsiva iyo yemagetsi conductivity yeanode inoshanda zvinhu.
2) Wedzera kuita kudzika uye chiyero chekushandisa.
3)Dzivisa chizvarwa che dendrites.
4) Shandisa iyo mvura-kunyudza kugona kwezvinhu zvinoitisa kuti uwedzere maitiro ekuita uye kuderedza polarization (inogona kuwedzerwa kana kwete maererano negraphite particle size distribution).
Zvinowedzera: Deredza kusadzoreka maitiro, kuwedzera simba rekubatanidza uye slurry viscosity, uye kudzivirira slurry sedimentation.
Thickener/anti{0}}settling agent (CMC): High molecular compound, inonyungudika zviri nyore mumvura ne polar solvents.
Isopropanol: Weakly polar zvinhu; mushure mekuwedzera, inogona kuderedza polarity yebinder solution, kuvandudza kuwirirana pakati pegraphite uye binder solution; ine simba rekubvisa furo simba; inogadzirisa nyore muchinjiko-kubatanidza kwemabinder network uye inonatsiridza kusimba kwekubatana.
Ethanol: isina simba polar zvinhu; mushure mekuwedzera, inogona kuderedza polarity yebinder solution, kuvandudza kuwirirana pakati pegraphite uye binder solution; ine simba rekubvisa furo simba; inogadzirisa zviri nyore linear cross-kubatanidza bhainda uye inonatsiridza kusimba kwekubatana (mashandiro eisopropanol ne ethanol zvakangofanana; kana uremu-uchigadzirwa, zvinhu zvinodhura zvinogona kutariswa sekusarudza yekuwedzera).
Mvura-based binder (SBR): Mabhondi graphite, conductive agent, additives, uye copper foil kana copper mesh pamwechete; linear chain emulsion molecule, yakanyanya kunyungudika mumvura uye polar solvents.
Mvura yakasvibiswa (kana mvura yakanyungudutswa): Diluent, yakawedzerwa muhuwandu hwakakodzera, inogona kuchinja fluidity yeslurry.
Anode tab: Yakagadzirwa nemhangura foil kana copper strip.
