Kev cuam tshuam los ntawm qib kub ntawm kev lag luam hluav taws xob tsheb,lithium-ion roj teeb, raws li ib tug ntawm cov tseem ceeb Cheebtsam ntawm hluav taws xob tsheb, tau hais txog mus rau ib tug zoo npaum li cas. Tib neeg tau cog lus los tsim lub neej ntev, lub zog siab, kev nyab xeeb zoo lithium-ion roj teeb. Ntawm lawv, lub attenuation ntawmlithium-ion roj teebmuaj peev xwm tsim nyog rau txhua tus neeg mloog, tsuas yog kev nkag siab tag nrho ntawm cov laj thawj rau kev txo qis ntawm lithium-ion roj teeb lossis cov txheej txheem, thiaj li yuav tau sau cov tshuaj zoo los daws qhov teeb meem, cov roj teeb lithium-ion muaj peev xwm yog vim li cas. attenuation?
Yog vim li cas rau lub peev xwm degradation ntawm lithium-ion roj teeb
1.Positive electrode khoom
LiCoO2 yog ib qho ntawm cov khoom siv cathode uas nquag siv (3C qeb yog dav siv, thiab cov roj teeb fais fab feem ntau nqa ternary thiab lithium hlau phosphate). Raws li tus naj npawb ntawm cov voj voog nce, qhov poob ntawm cov khoom siv lithium ions ua rau muaj peev xwm ua kom tawg ntau dua. Tom qab 200 lub voj voog, LiCoO2 tsis dhau mus rau theem hloov pauv, tab sis qhov hloov pauv ntawm cov qauv lamellar, ua rau muaj teeb meem hauv Li + de-embedding.
LiFePO4 muaj kev ruaj ntseg zoo, tab sis Fe3 + nyob rau hauv lub anode dissolves thiab txo rau Fe hlau ntawm graphite anode, ua rau muaj zog anode polarization. Feem ntau Fe3+ kev sib cais yog tiv thaiv los ntawm txheej txheej ntawm LiFePO4 hais los yog kev xaiv ntawm electrolyte.
NCM ternary cov ntaub ntawv ① Hloov pauv hlau ions hauv kev hloov pauv hlau oxide cathode cov khoom yog yooj yim rau yaj ntawm qhov kub thiab txias, yog li tso rau hauv cov electrolyte los yog tso rau ntawm qhov tsis zoo ua rau muaj peev xwm attenuation; ② Thaum qhov hluav taws xob siab dua 4.4V vs Li + / Li, kev hloov pauv ntawm cov khoom siv ternary ua rau muaj peev xwm degradation; ③ Li-Ni cov kab sib xyaw ua ke, ua rau muaj kev cuam tshuam ntawm Li+ raws.
Lub ntsiab ua rau muaj peev xwm degradation nyob rau hauv LiMnO4-raws lithium-ion roj teeb yog 1. irreversible theem los yog structural hloov, xws li lub Jahn-Teller aberration; thiab 2. dissolution ntawm Mn nyob rau hauv lub electrolyte (muaj HF nyob rau hauv lub electrolyte), disproportionation tshwm sim, los yog txo nyob rau hauv lub anode.
2.Cov ntaub ntawv tsis zoo electrode
Lub cim ntawm lithium nag lossis daus nyob rau sab anode ntawm graphite (ib feem ntawm lithium dhau los ua "lithium tuag" lossis tsim cov lithium dendrites), thaum qhov kub thiab txias, lithium ion diffusion qeeb qeeb yooj yim ua rau lithium nag lossis daus, thiab lithium nag lossis daus kuj tshwm sim. thaum N/P ratio tsawg dhau lawm.
Kev puas tsuaj rov qab thiab kev loj hlob ntawm SEI zaj duab xis ntawm sab anode ua rau lithium depletion thiab nce polarization.
Kev rov ua cov txheej txheem ntawm lithium embedding / de-lithium tshem tawm hauv silicon-raws li anode tuaj yeem yooj yim ua rau ntim ntim thiab tawg tsis ua haujlwm ntawm silicon hais. Yog li ntawd, rau silicon anode, nws yog ib qho tseem ceeb tshwj xeeb los nrhiav txoj hauv kev los inhibit nws qhov ntim nthuav dav.
3.Electrolyte
Cov yam ntxwv ntawm cov electrolyte uas ua rau muaj peev xwm degradation ntawmlithium-ion roj teebsuav nrog:
1. Kev puas tsuaj ntawm cov kuab tshuaj thiab cov electrolytes (qhov tsis ua haujlwm loj lossis teeb meem kev nyab xeeb xws li cov khoom siv roj), rau cov kuab tshuaj organic, thaum lub peev xwm oxidation ntau dua 5V vs. Li + / Li lossis txo qhov peev xwm qis dua 0.8V (qhov sib txawv electrolyte decomposition voltage yog txawv), yooj yim rau decompose. Rau electrolyte (xws li LiPF6), nws yog ib qho yooj yim rau decompose ntawm qhov kub thiab txias (dhau 55 ℃) vim tsis zoo stability;
2. Raws li tus naj npawb ntawm cov voj voog nce, cov tshuaj tiv thaiv ntawm cov electrolyte thiab qhov zoo thiab tsis zoo electrodes nce, ua rau lub zog hloov pauv tsis muaj zog.
4. Diaphragm
Lub diaphragm tuaj yeem thaiv cov electrons thiab ua tiav qhov kev sib kis ntawm ions. Txawm li cas los xij, lub peev xwm ntawm lub diaphragm los thauj Li + txo qis thaum lub diaphragm qhov raug thaiv los ntawm cov khoom decomposition ntawm cov electrolyte, thiab lwm yam, los yog thaum lub diaphragm shrinks ntawm kub kub, los yog thaum lub diaphragm muaj hnub nyoog. Tsis tas li ntawd, qhov tsim ntawm lithium dendrites tho lub diaphragm ua rau sab hauv luv luv Circuit Court yog qhov laj thawj tseem ceeb rau nws qhov tsis ua haujlwm.
5. Sau kua
Qhov ua rau muaj peev xwm poob vim yog lub collector feem ntau yog corrosion ntawm lub collector. Copper yog siv los ua cov khoom tsis zoo vim tias nws yooj yim rau oxidize ntawm qhov muaj peev xwm siab, thaum txhuas siv los ua cov khoom zoo vim nws yooj yim los tsim cov lithium-aluminium alloy nrog lithium ntawm qhov muaj peev xwm tsawg. Nyob rau hauv qis voltage (tsawg li 1.5V thiab qis dua, tshaj tawm), tooj liab oxidizes Cu2 + nyob rau hauv cov electrolyte thiab deposits nyob rau saum npoo ntawm cov electrode tsis zoo, cuam tshuam lub de-embedding ntawm lithium, ua rau muaj peev xwm degradation. Thiab ntawm qhov zoo, overcharging ntawm lubroj teebua rau pitting ntawm aluminium collector, uas ua rau muaj kev nce hauv kev ua haujlwm sab hauv thiab muaj peev xwm degradation.
6. Them nqi thiab tso tawm yam
Kev them nyiaj ntau dhau thiab tso tawm ntau dhau tuaj yeem ua rau muaj peev xwm ua kom nrawm ntawm cov roj teeb lithium-ion. Kev nce nqi / tso tawm ntau dua txhais tau hais tias qhov polarization impedance ntawm lub roj teeb nce raws li, ua rau muaj peev xwm txo qis. Tsis tas li ntawd, qhov kev ntxhov siab uas tshwm sim los ntawm kev them nyiaj thiab tawm ntawm qhov sib npaug siab ua rau poob ntawm cov khoom siv cathode thiab ua kom cov roj teeb nrawm nrawm.
Nyob rau hauv cov ntaub ntawv ntawm overcharging thiab overdischarging roj teeb, qhov tsis zoo electrode yog nquag rau lithium nag lossis daus, qhov zoo electrode ntau dhau lithium tshem tawm mechanism tsoo, thiab oxidative decomposition ntawm cov electrolyte (qhov tshwm sim ntawm by-products thiab roj ntau lawm) yog ceev. Thaum lub roj teeb tso tawm ntau dhau, cov ntawv ci tooj liab yuav yaj (txhim kho lithium de-embedding, lossis ncaj qha tsim tooj liab dendrites), ua rau muaj peev xwm degradation lossis roj teeb tsis ua haujlwm.
Cov kev tshawb fawb txog kev them nyiaj tau pom tias thaum lub them hluav taws xob txiav tawm yog 4V, qhov tsim nyog txo qhov kev them nyiaj txiav tawm (xws li 3.95V) tuaj yeem txhim kho lub voj voog lub neej ntawm lub roj teeb. Nws kuj tau pom tias ceev them lub roj teeb rau 100% SOC decays sai dua li them sai sai rau 80% SOC. Tsis tas li ntawd, Li et al. pom tau hais tias txawm tias pulsing tuaj yeem txhim kho qhov kev them nqi, qhov kev tiv thaiv sab hauv ntawm lub roj teeb yuav nce siab, thiab kev poob ntawm cov khoom siv hluav taws xob tsis zoo yog qhov hnyav.
7. Kub
Cov nyhuv ntawm qhov kub thiab txias ntawm lub peev xwm ntawmlithium-ion roj teebkuj tseem ceeb heev. Thaum ua haujlwm ntawm qhov kub siab dua rau lub sijhawm ntev, muaj kev nce ntxiv ntawm cov kev cuam tshuam sab hauv lub roj teeb (xws li, decomposition ntawm electrolyte), ua rau lub peev xwm tsis muaj peev xwm rov qab tau. Thaum ua haujlwm ntawm qhov kub thiab txias rau lub sijhawm ntev, tag nrho impedance ntawm lub roj teeb nce (electrolyte conductivity txo, SEI impedance nce, thiab tus nqi ntawm cov tshuaj tiv thaiv electrochemical txo qis), thiab lithium nag lossis daus los ntawm lub roj teeb yuav tshwm sim.
Cov saum toj no yog qhov laj thawj tseem ceeb rau lithium-ion roj teeb muaj peev xwm degradation, los ntawm cov lus qhia saum toj no Kuv ntseeg tias koj muaj kev nkag siab txog qhov ua rau lithium-ion roj teeb muaj peev xwm degradation.
Post lub sij hawm: Lub Xya hli ntuj-24-2023