Litšobotsi tsa Libetri tsa Lithium-ion ke Efe?
Capacity le Electromotive Force of Lithium-ion Battery Materials
Ka nako ya ho tjhaja-libetri tsa lithium-ioni, ke feela lisebelisoa tse sebetsang tsa li-electrode tse positive le negative tse bang teng ka lithium-ion intercalation/deintercalation reactions, athe electrolyte le lisebelisoa tse ling li sa sebelisoe. Ka hona, bokhoni boo lisebelisoa tsa elektrode tse ntle le tse mpe li kenellang ka morao/ho thella li-ion tsa lithium li etsa qeto ea hore na betri e bulehile hakae, 'me boholo ba li-ion tsa lithium tse kenellang/ho timana li etsa qeto ea hore na sesebelisoa se sebetsa ke sefe. Baetsi ba libeteri tsa lithium-ion ba bangata lefatšeng ka bophara le bafani ba libeteri tsa lithium{7}} ba itšetlehile ka litšobotsi tsena ho fumana tlhahiso ea bongata bo tsitsitseng le ts'ebetso e tsitsitseng ea sehlahisoa.
Bakeng sa electrode e mpe, karabelo e etsahala ho latela Equation (1.2). Ka molek'hule ea carbon (12g), boholo ba 1/6 mol ea lithium ion bo ka kopanngoa. Ka hona, theoretical itseng bokgoni ba carbon negative eleketrode lintho tse bonahalang ke
1/6(mol)×96485(Faraday constant,C/mol)/12(g)=3400C/g=372(mA·h/g) (1.5)
Tšebelisong ea letsatsi le letsatsi, ho nahanoa ka tahlehelo ea lithium ka lebaka la adsorption le ho thehoa ha filimi e tiileng ea electrolyte interphase (SEI), bokhoni ba sebele bo ka finyelloang ba lisebelisoa tsa carbon ke 300-345 mA·h / g. Batsweletsi ba ka sehloohong ba pakete ya betri ya lithium-ion ba fihlella boemo bona ka ho etsa graphite e ntlafaditsweng le mekgwa e nepahetseng ya ho roala.
Bakeng sa lisebelisoa tse ntle tsa electrode, matla a eona a itšetlehile ka boholo ba li-ion tsa lithium tse ka ntšoang / ho kenngoa. Ho nka LiCoO₂ e le mohlala, ho fihlela ho 1 mol ea lithium ion ka mole ea LiCoO₂ e ka kenya letsoho karabelong. Ka hona, bokhoni bo khethehileng ba khopolo-taba ea LiCoO₂ (boima bo amanang le molek'hule 97.86) ke
1(mol)×96485(C/mol)/97.86(g)=985.95C/g=273.9(mA·h/g) (1.6)
Ha e le hantle, ho boloka botsitso ba kristale ea thepa ea LiCoO₂, ka kakaretso ke 30% -60% feela ea li-ion tsa lithium tse kenyang letsoho ho arabela. Ka hona, matla a sebele a khethehileng a thepa ea LiCoO₂ ke 137-164 mA·h/g. Baetsi ba OEM ba betri ea lithium e kholo- ba laola botebo ba ho tjhaja le ho tjhaja ka BMS ho ntlafatsa bophelo ba nako le nako ha ba ntse ba netefatsa polokeho.
Bakeng sa lithium iron phosphate, 1 mol ea lithium ion ka mole ea lithium iron phosphate e ka kenya letsoho ka botlalo karabelong. Ka hona, matla a theoretical le a 'nete a matla a lithium iron phosphate material (boima ba molek'hule 157.8) ke
1(mol)×96485(C/mol)/157.8(g)=611.44C/g=169.8(mA·h/g) (1.7)
Ka tlhaho, matla a tloaelehileng a redox a Li/Li⁺ ke a tlase, a fihlang ho -3.04 V (ha e bapisoa le electrode e tloaelehileng ea hydrogen). Bakeng sa lisebelisoa tsa carbon negative electrode, monyetla oa ho ntša lithium-ion le ho kenngoa ho haufi le matla a ho lekana Li/Li⁺. Ho ea ka khopolo ea electrochemical, mocheso oa kamore, motlakase oa motlakase oa E oa electrode ea carbon negative ke
E=E℃+ 0.02567 · ln[C(Li⁺)/C(Li,C₆)] (1.8)
moo
Tekanyo ya E - bokgoni bo tlwaelehileng ba electrode;
C(Li⁺) - mahloriso a li-ion tsa lithium mothapong oa electrolyte;
C(Li,C₆) - mahloriso a li-ion tsa lithium ka har'a khabone ea electrode e mpe.
Ha motsoako oa lithium ion ka tharollo le ka har'a carbon electrode negative li le haufi, matla a electrode a electrode e mpe e lekana le tekanyo e tloaelehileng ea ho fokotsa tekanyo ea E. Ka kakaretso, lithium ion concentration ka electrolyte e tsitsitse, kahoo liphetoho tsa lithium ion concentration ka har'a carbon electrode negative li tla baka liphetoho ho matla a motlakase a fosahetseng. Hajoale ha ho na mokhoa o akaretsang oa ho bala bokhoni bo nepahetseng ba tekano ea Li/C₆ ka boleng bo fapaneng ba x. Ka kakaretso e khethoa ka liteko. Liteko li bonts'a hore bokhoni ba ho senyeha ha lisebelisoa tsa graphite{4}ka kakaretso bo fapana pakeng tsa 0–0.4 V (ha e bapisoa le Li/Li⁺), e leng se etsang hore e be lisebelisoa tse nepahetseng tsa li-electrode tse nepahetseng bakeng sa ts'ebeliso. Setšoantšo sa 1.2 se bonts'a tefiso e tloaelehileng{10}}mokhoa oa ho ntša motlakase oa graphite negative electrode.
Bakeng sa lisebelisoa tsa li-electrode tse ntle tsa LiCoO₂, lithium intercalation/deintercalation process ke -mohato o le mong. Ha motsoako oa lithium ion linthong tse ntle tsa electrode o fetoha, bokhoni ba electrode e ntle le bona boa fetoha. Ha ho nahanoa ka khokahanyo ea lithium ion ho electrolyte ke 1 mol/L, bakeng sa karabelo ho Equation (1.1), e ka bang electrode e ntle e ka bang teng.
E=E℃+ 0.02567 · ln[C(Li⁺,CoO₂)/C(LiCoO₂)] (1.9)
moo
Tekanyo ya E - bokgoni bo tlwaelehileng ba electrode;
C(LiCoO₂) - mahloriso a LiCoO₂ ka thepa e ntle ea electrode;
C(Li⁺,CoO₂) - mahloriso a Li⁺ le CoO₂ ka har'a lisebelisoa tse ntle tsa elektrode;
Ha li-ion tsa lithium li ntšoa, monyetla o motle oa elektrode o bonts'a mokhoa o tlase.
Tefiso-mokhoa oa ho ntša lithium iron phosphate material ke phetoho ho tloha ho lithium iron phosphate ho ea ho iron phosphate ka mor'a ho senyeha.
Karabelo ho electrode ea lithium iron phosphate ke
LiFePO₄ ↔ FePO₄ + Li⁺ + e⁻ (1.10)
Lithium{0}}ion intercalation/deintercalation process ke{1}}mekhahlelo e 'meli. Ka hona, liphetoho tsa lithium ion concentration ka thepa e ntle ea electrode ha e ame phetoho e ka bang teng ea electrode e ntle. Bokhoni ba eona ba ho lekana ke
E=E℃+ 0.02567 · ln[C(FePO₄)/C(LiFePO₄)] (1.11)
Motsoako oa lintho tse tiileng tse hloekileng ke 1. Ho itšetlehile ka litekanyo tsa eona tsa thermodynamic, tekano ea tekano ea theoretical ke 3.4 V.
Tefiso e tloaelehileng-e hlahisoang ke curve ea lithium iron phosphate material e bonts'oa setšoantšong sa 1.3.
Litšobotsi tsa Ts'ebetso ea Libetri tsa Lithium{0}}ion
Ha ho bapisoa le libeteri tse ling, libeteri tsa lithium-ion li na le litšobotsi tse latelang tse lemohuoang haholo ke baphatlalatsi ba libeteri tsa lithium-ion le bareki ba indasteri:
Matla a phahameng a matla.Matla a matla a libeteri tsa lithium{0}}ion li fihla ho 100 W·h/kg le 200 W·h/L kapa ho feta. Libetri tsa morao tjena tsa ternary cathode lithium{4}}ion li fumane matla a khethehileng a 200 W·h/kg. Ka ho sebelisa-nickel silicon{{8}e thehiloeng ho anode e thehiloeng ho lisebelisoa le lithium{9}}lisebelisoa tse nonneng tsa cathode, matla a khethehileng a lebelletsoe ho fihla ho 400 W·h/kg le boima ba matla a volumetric 900 W·h/L, bo fetang hōle libeteri tsa khale. Ka hona, libeteri tsa lithium{13}}li sebelisoa haholo ho lihlahisoa tsa elektroniki tse nkehang habonolo le likoloing tsa motlakase.
Matla a phahameng a bulehileng-a potoloho.Ka lebaka la ts'ebeliso ea -ea lihlapolli tse nang le metsi, motlakase o le mong-o fihla ho 3.6–3.8 V, e leng makhetlo a 2–3 a nickel{6}}metal hydride kapa nickel{7}}cadmium libetri. Ho sebelisa{9}voltage cathode e phahameng ka matla ho ka eketsa motlakase oa sele e le 'ngoe ho isa ho 4.5–5 V, e leng le leng la mabaka a bohlokoa a ho ba le matla a mangata a matla a betri ea lithium{12}}.
E khona ho-tefiso e phahameng le ho tsoa.Mohlala, libetri tsohle-tse tiileng-lithium tsa state-ion tsa ion tse sebelisang polymer electrolyte li ka fumana litefiso tsa ho tsoa ho feta 10C ka polokeho e ntle; lithium-libetri tsa ion tse sebelisang lithium iron phosphate kaha cathode e khona ho tsoa ka 100C.
Sekhahla se tlase- sa ho itokolla.Mocheso oa kamore, tekanyo ea khoeli le khoeli ea ho ntša libeteri tsa lithium-hang hangata e ka tlase ho 10%, e tlase ho feta libeteri tsa nickel{3}}metal hydride (15%) le halofo ea libeteri tsa nickel{5}}cadmium. Sekhahla sa ho itlhatsoa ha libeteri tsa lithium iron phosphate hangata se ka tlase ho 3%.
E baballa tikoloho,e se nang loto, cadmium, mercury, kapa dintho tse ding tse kotsi, mme ha e silafatse tikoloho.
Ha ho phello ea mohopolo.Matla a memori a bolela ketsahalo eo matla a betri a fokotsehang ha e tjhajwa hape pele e etswa kapa e sebediswa pele e tjhajwa ka botlalo (sephetho sa memori ha se ho bola ha matla). Libetri tsa lithium-ion ha li na matla a ho hopola.
Tšireletseho e ntle.Libetri tsa lithium-hang ka kakaretso li sebelisa lisebelisoa tsa k'habone joalo ka eleketrode e mpe, e nang le monyetla oa eleketrode e haufi le ea metallic lithium. Li-ion tsa lithium li ka kenella ka mokhoa o sa fetoheng 'me tsa kenella ka har'a khabone, tsa fokotsa haholo monyetla oa ho beoa ha tšepe ea lithium le ho ntlafatsa polokeho ea betri haholo. Lilemong tsa morao tjena, lisebelisuoa tse thibelang malakabe-li-retardant,{4}}retardant retardator, PTC (positive temperature coefficient) , explosion{5}valve e thibelang ho phatloha, lisebelisoa tsa ho laola libeteri, le mahlale a mang a netefalitse tšireletso e phahameng haholo ea libeteri tsa lithium{6}}.
Bophelo ba potoloho e telele.Nako ea nako ea libeteri tsa lithium-ion hangata e feta 500. Bophelo ba potoloho ea libeteri tsa lithium iron phosphate hangata ke li-cycle tse 2000-3000. Ha e bapisoa le litsamaiso tsa lisebelisoa tsa anode tse nang le bokhoni bo phahameng ba potoloho (joalo ka lithium titanate), li-cycle tse fetang 10,000 li ka finyelloa. Sena se etsa hore libeteri tsa lithium iron phosphate e be khetho e ntle ka ho fetisisa bakeng sa lisebelisoa tsa betri tsa polokelo ea matla le mesebetsi e meholo-ea ESS.
