Abstract
Cov roj teeb lithium-ion (LIBs) tau suav tias yog ib qho tseem ceeb tshaj plaws ntawm lub zog cia technologies.Raws li lub zog ceev ntawm cov roj teeb nce ntxiv, kev nyab xeeb ntawm roj teeb yuav tseem ceeb dua yog tias lub zog tso tawm tsis txhob txwm ua.Cov xwm txheej cuam tshuam nrog hluav taws kub thiab tawg ntawm LIBs tshwm sim ntau zaus thoob ntiaj teb.Qee qhov tau ua rau muaj kev hem thawj rau tib neeg lub neej thiab kev noj qab haus huv thiab tau ua rau ntau cov khoom lag luam rov qab los ntawm cov tuam txhab.Cov xwm txheej no yog ceeb toom tias kev nyab xeeb yog qhov yuav tsum tau ua ua ntej rau cov roj teeb, thiab cov teeb meem loj yuav tsum tau daws ua ntej yuav siv lub tshuab roj teeb uas muaj zog heev.Qhov Kev Ntsuam Xyuas no yog lub hom phiaj los sau cov ntsiab lus ntawm lub hauv paus chiv keeb ntawm LIB cov teeb meem kev nyab xeeb thiab qhia txog cov kev vam meej tseem ceeb tsis ntev los no hauv cov ntaub ntawv tsim los txhim kho LIB kev nyab xeeb.Peb cia siab tias qhov Kev Ntsuam Xyuas no yuav txhawb nqa kev txhim kho ntxiv hauv kev nyab xeeb ntawm roj teeb, tshwj xeeb tshaj yog rau LIBs uas muaj zog txaus.
LUB SIJ HAWM NTAWM LIB SAIB XYUAS
Cov organic kua electrolyte hauv LIBs yog intrinsically flammable.Ib qho kev puas tsuaj loj tshaj plaws ntawm LIB system yog qhov kev tshwm sim cascading thermal runaway, uas yog suav tias yog lub ntsiab ntawm kev txhawj xeeb txog kev nyab xeeb ntawm roj teeb.Feem ntau, thermal runaway tshwm sim thaum cov tshuaj tiv thaiv exothermic tawm ntawm kev tswj.Raws li qhov kub ntawm lub roj teeb nce siab tshaj ~ 80 ° C, cov tshuaj tiv thaiv exothermic nyob rau hauv cov roj teeb nce ntxiv thiab ua kom sov ntxiv rau lub xov tooj ntawm tes, ua rau muaj kev tawm tswv yim zoo.Qhov ntsuas kub tsis tu ncua tuaj yeem ua rau hluav taws kub thiab tawg, tshwj xeeb tshaj yog rau cov roj teeb loj.Yog li ntawd, kev nkag siab txog qhov ua rau thiab cov txheej txheem ntawm thermal runaway tuaj yeem coj tus qauv tsim cov khoom siv los txhim kho kev nyab xeeb thiab kev ntseeg siab ntawm LIBs.Cov txheej txheem thermal runaway tuaj yeem muab faib ua peb theem, raws li tau piav qhia hauvDaim duab 1.
Fig. 1 Peb theem rau cov txheej txheem thermal khiav.
Theem 1: Qhov pib ntawm overheating.Cov roj teeb hloov ntawm qhov qub mus rau lub xeev tsis zoo, thiab qhov kub ntawm sab hauv pib nce.Theem 2: Thaum tshav kub kub tsub zuj zuj thiab tso pa tawm txheej txheem.Qhov kub thiab txias sab hauv tau nce sai, thiab lub roj teeb ua rau muaj kev kub ntxhov.Theem 3: combustion thiab tawg.Cov nplaim hluav taws xob hluav taws xob hluav taws xob, ua rau hluav taws kub thiab txawm tias tawg.
Qhov pib ntawm overheating (theem 1)
Thermal runaway pib los ntawm overheating ntawm lub roj teeb system.Qhov pib overheating tuaj yeem tshwm sim vim yog lub roj teeb tau them dhau qhov tsim hluav taws xob (overcharging), raug rau qhov kub thiab txias, sab nraud luv Circuit Court vim yog qhov tsis zoo ntawm cov xaim hluav taws xob, lossis cov hluav taws xob luv luv vim yog cov xov tooj ntawm tes.Ntawm lawv, sab hauv luv luv yog qhov tseem ceeb tshaj plaws rau thermal runaway thiab yog qhov nyuaj rau tswj.Internal shorting tuaj yeem tshwm sim nyob rau hauv cov xwm txheej ntawm cov xovtooj ntawm tes xws li sab nraud hlau khib nyiab nkag;tsheb sib tsoo;lithium dendrite tsim nyob rau hauv high tam sim no ceev them, nyob rau hauv overcharging tej yam kev mob los yog nyob rau hauv qis kub;thiab flawed separators tsim thaum lub sij hawm sib dhos roj teeb, rau npe rau ob peb.Piv txwv li, thaum lub Kaum Hli Ntuj xyoo 2013, lub tsheb Tesla nyob ze Seattle tau tsoo cov hlau khib nyiab uas tau tho lub thaiv thiab cov roj teeb pob.Cov khib nyiab nkag mus rau cov khoom sib cais polymer thiab txuas ncaj qha rau cathode thiab anode, ua rau lub roj teeb luv luv thiab ntes hluav taws;Nyob rau hauv 2016, Samsung Note 7 roj teeb hluav taws yog vim lub aggressively ultrathin separator uas tau yooj yim puas los ntawm sab nraud siab los yog vuam burrs ntawm qhov zoo electrode, ua rau lub roj teeb luv luv.
Thaum lub sij hawm theem 1, lub roj teeb ua hauj lwm hloov ntawm ib txwm mus rau ib tug txawv txav lub xeev, thiab tag nrho cov teeb meem teev saum toj no yuav ua rau lub roj teeb overheat.Thaum qhov kub ntawm sab hauv pib nce, theem 1 xaus thiab theem 2 pib.
Thaum tshav kub kub thiab cov txheej txheem tso pa tawm (theem 2)
Raws li theem 2 pib, qhov kub thiab txias sab hauv tau nce sai, thiab lub roj teeb tau txais cov kev tshwm sim hauv qab no (cov kev cuam tshuam no tsis tshwm sim hauv qhov kev txiav txim kom meej; qee qhov ntawm lawv yuav tshwm sim ib txhij):
(1) Cov khoom electrolyte interphase (SEI) decomposition vim overheating los yog lub cev nkag mus rau hauv lub cev.SEI txheej feem ntau muaj qhov ruaj khov (xws li LiF thiab Li2CO3) thiab metastable [xws li polymers, ROCO2Li, (CH2OCO2Li)2, thiab ROLi] cov khoom.Txawm li cas los xij, cov khoom siv metastable tuaj yeem decompose exothermically ntawm kwv yees> 90 ° C, tso cov pa taws thiab cov pa oxygen.Siv (CH2OCO2Li)2 ua piv txwv
(CH2OCO2Li)2→Li2CO3+C2H4+CO2+0.5O2
(2) Nrog rau qhov decomposition ntawm SEI, qhov kub thiab txias tsim, thiab cov lithium hlau los yog intercalated lithium nyob rau hauv lub anode yuav hnov mob nrog cov organic solvents nyob rau hauv cov electrolyte, tso cov nplaim hluav taws xob hydrocarbon gases (ethane, methane, thiab lwm yam).Qhov no yog cov tshuaj tiv thaiv exothermic uas ua rau qhov kub thiab txias nce ntxiv.
(3) ThaumT> ~ 130 ° C, polyethylene (PE) / polypropylene (PP) separator pib yaj, uas ntxiv deteriorates qhov teeb meem thiab ua rau ib tug luv luv Circuit Court ntawm cathode thiab anode.
(4) Thaum kawg, cua sov ua rau cov khoom siv lithium hlau oxide cathode decomposition thiab ua rau tso pa tawm.Siv LiCoO2 ua piv txwv, uas tuaj yeem decompose pib ntawm ~ 180 ° C raws li hauv qab no
Kev tawg ntawm cov cathode kuj yog exothermic heev, ntxiv rau qhov kub thiab txias thiab, yog li ntawd, ntxiv ceev cov tshuaj tiv thaiv.
Thaum lub sij hawm theem 2, kub nce thiab oxygen accumulates nyob rau hauv cov roj teeb.Thermal runaway txheej txheem pib los ntawm theem 2 mus rau theem 3 sai li sai tau raws li cov pa oxygen txaus thiab cua sov tau sau rau roj teeb combustion.
combustion thiab tawg (theem 3)
Nyob rau theem 3, combustion pib.Cov electrolytes ntawm LIBs yog cov organic, uas yuav luag universal ua ke ntawm cyclic thiab linear alkyl carbonates.Lawv muaj volatility siab thiab yog intrinsically heev flammable.Kev siv cov carbonate electrolyte nrov [qhov sib xyaw ntawm ethylene carbonate (EC) + dimethyl carbonate (DMC) (1: 1 los ntawm qhov hnyav)] ua piv txwv, nws nthuav tawm lub vapor siab ntawm 4.8 kPa ntawm chav tsev kub thiab lub teeb nyem tsis tshua muaj. ntawm 25 ° ± 1 ° C ntawm huab cua siab ntawm 1.013 bar.Qhov tso pa tawm thiab cua sov hauv theem 2 muab cov xwm txheej uas yuav tsum tau ua rau cov hluav taws kub nyhiab ntawm cov organic electrolytes, yog li ua rau hluav taws kub lossis tawg.
Hauv theem 2 thiab 3, cov exothermic cov tshuaj tiv thaiv tshwm sim nyob rau hauv ze-adibatic mob.Yog li, ceev tus nqi calorimetry (ARC) yog ib tug dav siv cov txheej txheem uas simulates ib puag ncig nyob rau hauv lub LIBs, uas ua rau peb nkag siab txog cov thermal runaway cov tshuaj tiv thaiv kinetics.Daim duab 2qhia tau hais tias tus qauv ARC nkhaus ntawm LIB tau kaw thaum lub sij hawm ntsuas kev tsim txom thermal .Simulating qhov kub nce nyob rau theem 2, ib qho chaw sab nraud ntawm cov cua sov ua rau lub roj teeb kub nce mus rau qhov pib kub.Saum toj no qhov kub thiab txias, SEI decomposes, uas yuav ua rau ntau exothermic tshuaj tiv thaiv.Thaum kawg, lub separator yuav yaj.Cov cua kub ntawm tus kheej yuav nce ntxiv tom qab, ua rau thermal khiav (thaum tus nqi cua sov ntawm tus kheej yog> 10 ° C / min) thiab electrolyte combustion (theem 3).
Lub anode yog mesocarbon microbead graphite.Cov cathode yog LiNi0.8Co0.05Al0.05O2.Cov electrolyte yog 1.2 M LiPF6 hauv EC / PC / DMC.Celgard 2325 trilayer cais tau siv.Hloov kho nrog kev tso cai los ntawm Electrochemical Society Inc.
Nws yuav tsum raug sau tseg tias cov kev tshwm sim uas tau piav qhia saum toj no tsis nruj me ntsis tshwm sim ib qho tom qab lwm qhov hauv qhov kev txiav txim.Lawv yog, theej, complex thiab systematic teeb meem.
Cov khoom siv nrog kev txhim kho roj teeb kev nyab xeeb
Raws li kev nkag siab ntawm roj teeb thermal runaway, ntau txoj hauv kev tau kawm, nrog rau lub hom phiaj ntawm kev txo qis kev nyab xeeb los ntawm kev tsim qauv tsim ntawm cov roj teeb.Hauv seem ua tiav, peb sau cov ntaub ntawv sib txawv los txhim kho kev nyab xeeb ntawm roj teeb, daws cov teeb meem sib txawv ntawm cov txheej txheem thermal khiav.
Txhawm rau daws cov teeb meem hauv theem 1 (qhov pib ntawm overheating)
Txhim khu kev qha cov ntaub ntawv anode.Li dendrite tsim rau ntawm anode ntawm LIB pib thawj theem ntawm thermal runaway.Txawm hais tias qhov teeb meem no tau txo qis hauv anodes ntawm kev lag luam LIBs (piv txwv li, carbonaceous anodes), Li dendrite tsim tsis tau tag nrho inhibited.Piv txwv li, nyob rau hauv kev lag luam LIBs, dendrite deposition tshwm sim nyiam tshaj ntawm graphite electrode npoo yog cov anodes thiab cathodes tsis zoo ua ke.Tsis tas li ntawd, kev ua haujlwm tsis raug ntawm LIBs tuaj yeem ua rau Li hlau tso nyiaj nrog kev loj hlob ntawm dendrite.Nws paub zoo tias dendrite tuaj yeem tsim tau yooj yim yog tias lub roj teeb raug them (i) ntawm qhov ceev tam sim no qhov chaw tso nyiaj ntawm Li hlau sai dua li qhov sib txawv ntawm Li ions hauv cov graphite ntau;(ii) nyob rau hauv cov xwm txheej overcharge thaum graphite yog overlithiated;thiab (iii) ntawm qhov kub tsis tshua muaj [piv txwv li, qhov kub thiab txias (~ 0 ° C)], vim yog cov viscosity ntawm cov kua electrolyte thiab nce li-ion diffusion tsis kam.
Los ntawm qhov pom ntawm cov khoom siv, lub hauv paus keeb kwm txiav txim siab qhov pib ntawm Li dendrite txoj kev loj hlob ntawm lub anode yog qhov tsis ruaj tsis khov thiab nonuniform SEI, uas ua rau cov khoom tsis sib xws hauv zos tam sim no.Electrolyte Cheebtsam, tshwj xeeb tshaj yog additives, tau raug soj ntsuam los txhim kho SEI uniformity thiab tshem tawm Li dendrite tsim.Cov additives xws li inorganic compounds [piv txwv li, CO2 , LiI , thiab lwm yam.] thiab cov organic tebchaw uas muaj unsaturated carbon bonds xws li vinylene carbonate thiab maleimide additives;tsis ruaj tsis khov cyclic molecules xws li butyrolactone, ethylene sulfite, thiab lawv cov derivatives;thiab fluorinated compounds xws li fluoroethylene carbonate, thiab lwm yam.Txawm tias nyob rau theem-ib lab, cov molecules no tseem tuaj yeem txhim kho SEI morphology, yog li homogenizing Li-ion flux thiab tshem tawm qhov muaj peev xwm ntawm Li dendrite tsim.
Zuag qhia tag nrho, Li dendrite cov kev cov nyom tseem muaj nyob rau hauv graphite los yog carbonaceous anodes thiab silicon/SiO uas muaj lwm tiam anodes.Kev daws qhov teeb meem ntawm Li dendrite txoj kev loj hlob yog ib qho kev sib tw uas yog ib qho tseem ceeb rau kev hloov pauv ntawm cov khoom siv hluav taws xob siab Li-ion chemistry nyob rau yav tom ntej.Nws yuav tsum raug sau tseg tias, tsis ntev los no, kev siv zog ntau tau mob siab rau los daws qhov teeb meem ntawm Li dendrite tsim nyob rau hauv ntshiab Li hlau anodes los ntawm homogenizing Li-ion flux thaum lub sij hawm Li deposition;Piv txwv li, kev tiv thaiv txheej txheej, khoom siv SEI engineering , thiab lwm yam. Hauv qhov no, qee txoj hauv kev tuaj yeem ua teeb pom kev zoo rau kev daws qhov teeb meem ntawm carbonaceous anodes hauv LIBs thiab.
Multifunctional kua electrolytes thiab separators.Cov kua electrolyte thiab separator ua lub luag haujlwm tseem ceeb hauv lub cev sib cais lub zog cathode thiab anode.Yog li, tsim tau zoo tsim cov khoom siv hluav taws xob ntau thiab cov khoom sib cais tuaj yeem tiv thaiv cov roj teeb thaum ntxov ntawm cov roj teeb thermal runaway (theem 1).
Txhawm rau tiv thaiv cov roj teeb los ntawm kev sib tsoo, lub shear thickening kua electrolyte tau txais los ntawm qhov yooj yim ntxiv ntawm fumed silica rau carbonate electrolyte (1 M LiFP6 hauv EC / DMC).Raws li cov neeg kho tshuab siab los yog kev cuam tshuam, cov kua ua kom pom cov nyhuv shear thickening nrog kev nce hauv viscosity, yog li dissipating lub zog cuam tshuam thiab ua kom pom kev ua siab ntev rau crushing (Fig. 3 A)
Fig. 3 Cov tswv yim los daws cov teeb meem hauv theem 1.
(A) Shear thickening electrolyte.Sab saum toj: Rau cov electrolyte ib txwm muaj, kev cuam tshuam rau txhua yam tuaj yeem ua rau lub roj teeb hauv lub sijhawm luv, ua rau hluav taws kub thiab tawg.Hauv qab: Cov tshiab ntse electrolyte nrog shear thickening nyhuv nyob rau hauv lub siab los yog kev cuam tshuam qhia tau zoo heev kam rau ua crushing, uas yuav ho txhim kho cov neeg kho tshuab kev nyab xeeb ntawm roj teeb.(B) Bifunctional separators rau kev tshawb pom ntxov ntawm lithium dendrites.Dendrite tsim nyob rau hauv ib txwm lithium roj teeb, qhov twg ua tiav kev nkag mus ntawm lub separator los ntawm ib tug lithium dendrite tsuas yog kuaj tau thaum lub roj teeb tsis ua hauj lwm vim yog ib tug luv luv Circuit Court.Nyob rau hauv kev sib piv, ib tug lithium roj teeb nrog ib tug bifunctional separator (suav nrog ib tug txheej txheej sandwiched ntawm ob pa sib cais), qhov twg cov overgrown lithium dendrite nkag mus rau hauv lub separator thiab ua rau kev sib cuag nrog cov txheej tooj liab, uas ua rau ib tug poob rau hauv.VCu-Li, uas ua haujlwm ceeb toom ntawm kev ua tsis tiav vim muaj kev cuam tshuam sab hauv.Txawm li cas los xij, lub roj teeb tag nrho tseem muaj kev nyab xeeb ua haujlwm nrog tsis muaj peev xwm.(A) thiab (B) raug hloov kho lossis rov tsim dua nrog kev tso cai los ntawm Springer Nature.(C) Trilayer cais kom haus Li dendrites txaus ntshai thiab ua kom lub roj teeb ntev.Sab laug: Lithium anodes tau yooj yim tsim dendritic deposits, uas yuav maj mam loj hlob thiab nkag mus rau inert polymer cais.Thaum cov dendrites thaum kawg txuas cov cathode thiab anode, lub roj teeb luv luv thiab tsis ua haujlwm.Txoj Cai: Ib txheej ntawm silica nanoparticles yog sandwiched los ntawm ob txheej ntawm cov khoom lag luam polymer cais.Yog li ntawd, thaum lithium dendrites loj hlob thiab nkag mus rau hauv lub separator, lawv yuav hu rau silica nanoparticles nyob rau hauv lub sandwiched txheej thiab yuav siv electrochemically.(D) Scanning electron microscopy (SEM) duab ntawm silica nanoparticle sandwiched separator.(E) Hom voltage piv rau lub sij hawm profile ntawm Li / Li roj teeb nrog cov pa sib cais (liab nkhaus) thiab silica nanoparticle sandwiched trilayer separator (dub nkhaus) sim nyob rau hauv tib lub sijhawm.(C), (D), thiab (E) raug tsim tawm nrog kev tso cai los ntawm John Wiley thiab Cov Tub.(F) Schematic illustration ntawm lub mechanisms ntawm redox shuttle additives.Ntawm qhov chaw overcharged cathode, redox additive yog oxidized rau hauv daim ntawv [O], uas tom qab ntawd yuav raug txo rov qab mus rau nws thawj lub xeev [R] nyob rau saum npoo ntawm lub anode los ntawm diffusion los ntawm electrolyte.Lub voj voog hluav taws xob hluav taws xob ntawm oxidation-diffusion-txo-diffusion tuaj yeem khaws cia tsis tu ncua thiab yog li xauv lub peev xwm cathode los ntawm kev phom sij overcharging.(G) Cov qauv tshuaj lom neeg ntawm redox shuttle additives.(H) Cov txheej txheem ntawm kev kaw cov khoom siv nyiaj ntau dhau uas tuaj yeem electrochemically polymerize ntawm qhov muaj peev xwm siab.(I) Cov qauv tshuaj lom neeg ntawm kev kaw cov khoom siv nyiaj ntau dhau.Lub peev xwm ua haujlwm ntawm cov tshuaj ntxiv tau teev tseg hauv txhua tus qauv molecular hauv (G), (H), thiab (I).
Separators tuaj yeem siv hluav taws xob insulate lub cathode thiab anode thiab ua lub luag haujlwm tseem ceeb hauv kev saib xyuas kev noj qab haus huv ntawm lub roj teeb hauv qhov chaw kom tsis txhob muaj kev puas tsuaj ntxiv dhau los ntawm theem 1. Piv txwv li, "bifunctional separator" nrog lub polymer-hlau-polymer trilayer configuration (Fig. 3B) tuaj yeem muab lub zog tshiab-sensing muaj nuj nqi.Thaum lub dendrite loj hlob tuaj thiab ncav cuag cov txheej txheem nruab nrab, nws yuav txuas cov hlau txheej thiab cov anode xws li qhov tam sim no qhov hluav taws xob poob ntawm lawv tuaj yeem tshawb pom tam sim ntawd raws li qhov tso tawm.
Dhau li ntawm kev kuaj pom, lub trilayer cais tau tsim los siv cov Li dendrites txaus ntshai thiab ua rau lawv txoj kev loj hlob qeeb tom qab nkag mus rau qhov sib cais.Ib txheej ntawm silica nanoparticles, sandwiched los ntawm ob txheej ntawm kev lag luam polyolefin separators (Daim duab 3, C thiab D), tuaj yeem haus txhua yam kev phom sij Li dendrites, yog li txhim kho lub roj teeb kev nyab xeeb.Lub neej ntawm lub roj teeb tiv thaiv tau txuas ntxiv los ntawm kwv yees li tsib zaug piv nrog rau qhov muaj cov pa sib cais (Fig. 3 E).
Kev tiv thaiv overcharge.Overcharging txhais tau tias yog them lub roj teeb dhau ntawm nws qhov hluav taws xob tsim.Overcharging yuav ua rau muaj cov nqi tshwj xeeb tam sim no, thiab lwm yam, uas tuaj yeem coj cov roj ntsha ntawm lub roj teeb electrochemical thiab kev nyab xeeb;(ii) decomposition ntawm cov khoom cathode, tso pa oxygen;thiab (iii) decomposition ntawm cov organic electrolyte, tso cua sov thiab gaseous khoom (H2, hydrocarbons, CO, thiab lwm yam), uas yog lub luag hauj lwm rau thermal runaway.Cov tshuaj tiv thaiv electrochemical thaum lub sij hawm decomposition yog qhov nyuaj, qee qhov ntawm cov npe hauv qab no.
Lub hnub qub (*) txhais tau hais tias cov roj hydrogen pib los ntawm cov protic, tawm hauv cov pab pawg tsim tawm thaum lub sij hawm oxidation ntawm carbonates ntawm cathode, uas tom qab ntawd diffuse rau lub anode kom txo tau thiab tsim H2.
Raws li qhov sib txawv ntawm lawv txoj haujlwm, cov khoom siv tiv thaiv overcharge tuaj yeem raug cais raws li redox shuttle additives thiab kaw cov khoom ntxiv.Tus qub tiv thaiv lub xov tooj ntawm tes los ntawm overcharge reversibly, thaum lub sij hawm tom kawg terminates cell ua hauj lwm mus tas li.
Redox shuttle additives ua haujlwm los ntawm electrochemically shunting tus nqi tshaj tawm rau hauv lub roj teeb thaum overcharge tshwm sim.Raws li qhia hauvFig. 3 F, lub tshuab yog ua raws li redox additive uas muaj peev xwm oxidation qis dua li ntawm cov electrolyte anodic decomposition.Nyob rau hauv lub overcharged cathode nto, lub redox additive yog oxidized rau hauv daim ntawv [O], uas tom qab ntawd yuav raug txo rov qab mus rau nws thawj lub xeev [R] nyob rau saum npoo ntawm lub anode tom qab diffusion los ntawm electrolyte.Tom qab ntawd, qhov txo qis ntxiv tuaj yeem rov qab mus rau cathode, thiab lub voj voog hluav taws xob ntawm "oxidation-diffusion-reduction-diffusion" tuaj yeem khaws cia tsis tu ncua thiab yog li xauv lub peev xwm cathode los ntawm kev phom sij ntxiv.Cov kev tshawb fawb tau pom tias lub peev xwm redox ntawm cov khoom siv ntxiv yuav tsum yog li 0.3 txog 0.4 V siab tshaj qhov peev xwm ntawm cov cathode.
Cov tshuaj ntxiv nrog cov qauv tsim tshuaj zoo thiab cov peev txheej redox tau tsim, suav nrog organometallic metallocenes, phenothiazines, triphenylamines, dimethoxybenzenes thiab lawv cov derivatives, thiab 2-(pentafluorophenyl)-tetrafluoro-1,3,2-benzodioxaborole (Fig. 3 G).Los ntawm kev tsim cov qauv molecular, qhov muaj peev xwm oxidation ntxiv tuaj yeem hloov mus rau saum toj 4 V, uas yog tsim rau cov khoom siv hluav taws xob cathode sai sai thiab cov electrolytes.Lub hauv paus ntsiab lus tsim los txo qis qhov siab tshaj plaws nyob hauv molecular orbital ntawm cov khoom ntxiv los ntawm kev ntxiv cov khoom siv hluav taws xob rho tawm, ua rau muaj peev xwm oxidation ntxiv.Dhau li ntawm cov organic additives, qee cov ntsev inorganic, uas tsis tsuas yog tuaj yeem ua haujlwm raws li cov ntsev electrolyte, tab sis kuj tuaj yeem ua haujlwm ua lub tsheb thauj mus los, xws li perfluoroborane pawg ntsev [uas yog, lithium fluorododecaborates (Li2B12F).xH12-x)], kuj tau pom tias muaj txiaj ntsig redox shuttle additives .
Shutdown overcharge additives yog ib chav kawm ntawm irreversible overcharge tiv thaiv additives.Lawv ua haujlwm los ntawm kev tso pa tawm ntawm qhov muaj peev xwm siab, uas, dhau los, ua kom muaj kev cuam tshuam tam sim no, lossis los ntawm kev mus tas li electrochemically polymerizing ntawm qhov muaj peev xwm los txiav tawm lub roj teeb ua haujlwm ua ntej muaj kev puas tsuaj tshwm sim (Fig. 3 H).Piv txwv ntawm yav dhau los muaj xws li xylene , cyclohexylbenzene , thiab biphenyl , thaum piv txwv ntawm cov tom kawg muaj xws li biphenyl thiab lwm cov tshuaj tsw qab hloov pauv (Fig. 3 I).Qhov cuam tshuam tsis zoo ntawm kev kaw cov tshuaj ntxiv yog tseem ua haujlwm ntev thiab kev cia khoom ntawm LIBs vim yog qhov tsis tuaj yeem oxidation ntawm cov tebchaw.
Txhawm rau daws cov teeb meem hauv theem 2 (kev sib sau ua ke thiab cov roj tso tawm)
Cov khoom siv cathode ntseeg tau.Lithium hloov pauv hlau oxides, xws li txheej oxides LiCoO2, LiNiO2, thiab LiMnO2;spinel-type oxide LiM2O4;thiab polyanion hom LiFePO4, yog cov khoom siv cathode, uas, txawm li cas los xij, muaj teeb meem kev nyab xeeb tshwj xeeb tshaj yog thaum kub kub.Ntawm lawv, olivine-structured LiFePO4 kuj muaj kev nyab xeeb, uas ruaj khov mus txog 400 ° C, thaum LiCoO2 pib decompose ntawm 250 ° C.Yog vim li cas rau kev txhim kho kev nyab xeeb ntawm LiFePO4 yog tias tag nrho cov pa oxygen ions tsim muaj zog covalent daim ntawv cog lus nrog P5 + los ua PO43- tetrahedral polyanions, uas ruaj khov rau tag nrho peb-seem lub moj khaum thiab muab kev ruaj ntseg zoo dua piv nrog rau lwm cov ntaub ntawv cathode, txawm tias tseem muaj. tau qee lub roj teeb hluav taws xob tau tshaj tawm.Qhov kev txhawj xeeb txog kev nyab xeeb loj yog tshwm sim los ntawm qhov decomposition ntawm cov khoom siv cathode ntawm qhov kub thiab txias ib txhij tso tawm, uas ua ke tuaj yeem ua rau combustion thiab tawg, ua rau muaj kev puas tsuaj loj ntawm roj teeb.Piv txwv li, cov qauv siv lead ua ntawm txheej txheej oxide LiNiO2 tsis ruaj khov vim tias muaj Ni2 +, qhov loj me me uas zoo ib yam li Li +.Tus txiv tsev LixNiO2 (x< 1) zoo li hloov mus rau qhov ruaj khov spinel-hom theem LiNi2O4 (spinel) thiab rocksalt-type NiO, nrog oxygen tso rau hauv cov kua electrolyte ntawm ib ncig ntawm 200 ° C, ua rau electrolyte combustion.
Kev siv zog ntau dua tau ua los txhim kho thermal stability ntawm cov ntaub ntawv cathode los ntawm atom doping thiab cov txheej tiv thaiv nto.
Atom doping tuaj yeem ua rau kom muaj kev ruaj ntseg ntawm cov khoom siv oxide txheej vim qhov ua kom ruaj khov siv lead ua.Lub thermal stability ntawm LiNiO2 los yog Li1.05Mn1.95O4 tuaj yeem txhim kho tau zoo los ntawm kev hloov ib nrab ntawm Ni lossis Mn nrog lwm cov hlau cations, xws li Co, Mn, Mg, thiab Al .Rau LiCoO2, kev qhia txog doping thiab alloying cov ntsiab lus xws li Ni thiab Mn tuaj yeem ua rau kom qhov kub thiab txias.Tdec, thaum tseem tsis txhob muaj kev cuam tshuam nrog electrolyte ntawm qhov kub thiab txias.Txawm li cas los xij, kev nce hauv cathode thermal stability feem ntau tuaj nrog kev txi hauv lub peev xwm tshwj xeeb.Txhawm rau daws qhov teeb meem no, cov khoom siv cathode concentration-gradient rau rechargeable lithium roj teeb raws li txheej txheej lithium nickel cobalt manganese oxide tau tsim (Fig. 4 A) .Nyob rau hauv cov ntaub ntawv no, txhua particle muaj ib tug Ni-nplua nuj central bulk thiab ib tug Mn-nplua nuj txheej txheej, nrog txo Ni concentration thiab nce Mn thiab Co concentrations raws li cov nto mus txog (Fig. 4B).Lub qub muab lub peev xwm siab, whereas tom kawg txhim kho thermal stability.Cov khoom siv cathode tshiab no tau pom los txhim kho kev nyab xeeb ntawm cov roj teeb yam tsis muaj kev cuam tshuam lawv cov kev ua haujlwm electrochemical (Fig. 4 C).
Fig. 4 Cov Tswv Yim los daws cov teeb meem hauv theem 2: Kev ntseeg siab cathodes.
(A) Schematic daim duab ntawm ib tug zoo electrode particle nrog ib tug Ni-nplua nuj core surrounded los ntawm ib tug concentration-gradient txheej txheej.Txhua qhov khoom muaj Ni-nplua nuj hauv nruab nrab Li (Ni0.8Co0.1Mn0.1)O2 thiab Mn-nplua nuj txheej txheej [Li(Ni0.8Co0.1Mn0.1)O2] nrog txo Ni concentration thiab nce Mn thiab Co concentrations raws li qhov saum npoo yog ze.Lub qub muab lub peev xwm siab, whereas lub tom kawg txhim kho cov thermal stability.Qhov nruab nrab muaj pes tsawg leeg yog Li(Ni0.68Co0.18Mn0.18)O2.Ib tug scanning electron micrograph ntawm ib tug raug particle kuj qhia nyob rau sab xis.(B) Electron-probe x-ray microanalysis cov txiaj ntsig ntawm qhov kawg lithiated oxide Li(Ni0.64Co0.18Mn0.18)O2.Qhov kev hloov pauv me ntsis ntawm Ni, Mn, thiab Co nyob rau hauv lub interlayer yog pom tseeb.Ni concentration txo qis, thiab Co thiab Mn concentrations nce mus rau saum npoo.(C) Differential scanning calorimetry (DSC) cov kab uas qhia tias kub ntws los ntawm cov tshuaj tiv thaiv ntawm cov electrolyte nrog concentration-gradient khoom Li (Ni0.64Co0.18Mn0.18) O2, Ni-nplua nuj central khoom Li (Ni0.8Co0.1Mn0. 1) O2, thiab Mn-nplua nuj txheej txheej [Li(Ni0.46Co0.23Mn0.31)O2].Cov ntaub ntawv raug them rau 4.3 V. (A), (B), thiab (C) raug tsim tawm nrog kev tso cai los ntawm Springer Nature.(D) Sab laug: Transmission electron microscopy (TEM) bright-field duab ntawm AlPO4 nanoparticle-coated LiCoO2;lub zog dispersive x-ray spectrometry paub meej txog Al thiab P Cheebtsam hauv txheej txheej.Txoj Cai: High-resolution TEM duab qhia cov AlPO4 nanoparticles (~ 3 nm inch) nyob rau hauv nanoscale txheej txheej;cov xub qhia qhov cuam tshuam ntawm AlPO4 txheej thiab LiCoO2.(E) Sab laug: Ib daim duab ntawm lub xov tooj ntawm tes uas muaj LiCoO2 cathode liab qab tom qab 12-V overcharge test.Lub cell hlawv thiab tawg ntawm qhov voltage.Txoj Cai: Daim duab ntawm lub xov tooj ntawm tes uas muaj AlPO4 nanoparticle-coated LiCoO2 tom qab 12-V overcharge test.(D) thiab (E) raug luam tawm nrog kev tso cai los ntawm John Wiley thiab Tub.
Lwm lub tswv yim los txhim kho kev ruaj ntseg thermal yog los npog cov khoom siv cathode nrog kev tiv thaiv nyias txheej ntawm thermally ruaj khov Li + kev sib txuas, uas tuaj yeem tiv thaiv kev sib cuag ncaj qha ntawm cov ntaub ntawv cathode nrog electrolyte thiab yog li txo cov kev cuam tshuam sab nraud thiab tsim hluav taws xob.Cov coatings tuaj yeem yog cov yeeb yaj kiab uas tsis muaj tshuaj lom [piv txwv li, ZnO, Al2O3, AlPO4, AlF3, thiab lwm yam], uas tuaj yeem coj Li ions tom qab lithiated (Daim duab 4, D thiab E), los yog cov yeeb yaj kiab organic, xws li poly (diallyldimethylammonium chloride), cov yeeb yaj kiab tiv thaiv tsim los ntawm γ-butyrolactone additives, thiab multicomponent additives (muaj vinylene carbonate, 1,3-propylene sulfite, thiab dimethylacetamide).
Qhia txog txheej txheej nrog qhov zoo ntawm qhov kub thiab txias coefficient kuj ua tau zoo rau kev ua kom muaj kev nyab xeeb cathode.Piv txwv li, poly (3-decylthiophene)-coated LiCoO2 cathodes tuaj yeem kaw cov tshuaj tiv thaiv hluav taws xob thiab sab nraud thaum qhov kub thiab txias nce mus txog> 80 ° C, raws li cov txheej txheem polymer tuaj yeem hloov pauv mus rau lub xeev muaj zog heev.Coatings ntawm tus kheej-terminated oligomers nrog hyper-branched architecture kuj tseem ua haujlwm raws li thermally teb thaiv txheej los kaw lub roj teeb ntawm sab cathode.
Thermally switchable tam sim no collector.Kev kaw ntawm cov tshuaj tiv thaiv electrochemical thaum lub roj teeb kub nce ntawm theem 2 tuaj yeem tiv thaiv qhov kub thiab txias kom tsis txhob nce ntxiv.Qhov ceev thiab thim rov qab thermoresponsive polymer switching (TRPS) tau muab tso rau sab hauv rau hauv cov khoom tam sim no (Fig. 5 A) .TRPS nyias zaj duab xis muaj cov conductive graphene-coated spiky nanostructured npib tsib xee (GrNi) hais raws li cov conductive muab tub lim thiab ib tug PE matrix nrog ib tug loj thermal expansion coefficient (α ~ 10-4 K-1).Raws li-fabricated polymer composite films qhia high conductivity (σ) nyob rau hauv chav tsev kub, tab sis thaum kub mus txog rau lub switching kub (Ts), conductivity txo nyob rau hauv 1 s los ntawm xya mus rau yim qhov kev txiav txim ntawm magnitude raws li ib tug tshwm sim ntawm polymer ntim expansion, uas cais cov conductive hais thiab lov cov conductive txoj kev (Fig. 5 B).Cov zaj duab xis instantaneously ua insulating thiab yog li terminates lub roj teeb ua hauj lwm (Fig. 5 C).Cov txheej txheem no yog thim rov qab heev thiab tuaj yeem ua haujlwm txawm tias tom qab ntau qhov xwm txheej overheating yam tsis muaj kev cuam tshuam qhov kev ua tau zoo.
Fig. 5 Cov tswv yim los daws cov teeb meem hauv theem 2.
(A) Schematic illustration ntawm thermal switching mechanism ntawm TRPS tam sim no collector.Lub roj teeb muaj kev nyab xeeb muaj ib lossis ob lub tshuab tam sim no coated nrog ib txheej TRPS nyias.Nws ua haujlwm ib txwm nyob ntawm chav tsev kub.Txawm li cas los xij, nyob rau hauv cov ntaub ntawv ntawm qhov kub thiab txias tam sim no loj, lub polymer matrix nthuav, yog li cais cov conductive hais, uas yuav txo tau nws conductivity, zoo heev ua rau nws tsis kam thiab kaw lub roj teeb.Cov qauv roj teeb tuaj yeem tiv thaiv tsis muaj kev puas tsuaj.Thaum txias, lub polymer shrinks thiab regains tus thawj conductive txoj kev.(B) Kev hloov pauv ntawm cov yeeb yaj kiab TRPS sib txawv raws li kev ua haujlwm ntawm qhov kub thiab txias, suav nrog PE / GrNi nrog qhov sib txawv GrNi loadings thiab PP / GrNi nrog 30% (v / v) loading ntawm GrNi.(C) Cov ntsiab lus muaj peev xwm ntawm LiCoO2 roj teeb muaj kev nyab xeeb kev caij tsheb kauj vab ntawm 25 ° C thiab kaw.Qhov zero muaj peev xwm ntawm 70 ° C qhia tias kaw tag nrho.(A), (B), thiab (C) raug tsim tawm nrog kev tso cai los ntawm Springer Nature.(D) Schematic sawv cev ntawm microsphere-based shutdown tswvyim rau LIBs.Electrodes tau ua haujlwm nrog cov thermoresponsive microspheres uas, siab dua qhov tseem ceeb hauv roj teeb kub, dhau los ntawm kev hloov pauv thermal (melt).Lub molten capsules coated lub electrode nto, tsim ib qho ionically insulating barrier thiab kaw lub roj teeb ntawm tes.(E) Ib daim nyias nyias thiab nws tus kheej-sawv inorganic composite daim nyias nyias muaj li ntawm 94% alumina hais thiab 6% styrene-butadiene roj hmab (SBR) binder tau npaj los ntawm kev daws cov txheej txheem casting.Txoj Cai: Cov duab qhia txog thermal stability ntawm inorganic composite separator thiab PE separator.Cov sib cais tau tuav ntawm 130 ° C rau 40 min.Lub PE tau poob qis los ntawm thaj chaw nrog lub dotted square.Txawm li cas los xij, cov khoom sib xyaw ua ke tsis tau qhia pom tseeb shrinkage.Rov ua dua nrog kev tso cai los ntawm Elsevier.(F) Cov qauv molecular ntawm qee qhov kub-melting polymers ua cov khoom sib cais uas tsis tshua muaj qhov kub thiab txias.Sab saum toj: polyimide (PI).Nruab nrab: cellulose.Hauv qab: poly (butylene) terephthalate.(G) Sab laug: Kev sib piv ntawm DSC spectra ntawm PI nrog PE thiab PP cais;PI cais qhia tau zoo heev thermal stability ntawm qhov kub ntawm 30 ° txog 275 ° C.Txoj Cai: Cov duab digital koob yees duab sib piv cov wettability ntawm cov khoom lag luam sib cais thiab cov khoom sib xyaw PI cais nrog propylene carbonate electrolyte.Rov ua dua nrog kev tso cai los ntawm American Chemical Society.
Thermal shutdown separators.Lwm lub tswv yim los tiv thaiv cov roj teeb los ntawm thermal runaway thaum lub sij hawm theem 2 yog kaw txoj kev conduction ntawm Li ions los ntawm lub separator.Cov khoom sib cais yog cov khoom tseem ceeb rau kev nyab xeeb ntawm LIBs, vim tias lawv tiv thaiv hluav taws xob ncaj qha ntawm cov khoom siv hluav taws xob cathode thiab cov khoom siv anode thaum tso cai rau kev thauj mus los ionic.PP thiab PE yog cov khoom siv feem ntau, tab sis lawv muaj qhov tsis zoo thermal stability, nrog cov ntsiab lus melting ntawm ~ 165 ° thiab ~ 135 ° C, raws li.Rau kev lag luam LIB, cov khoom sib cais nrog PP / PE / PP trilayer qauv twb tau ua lag luam, qhov twg PE yog txheej nruab nrab tiv thaiv.Thaum qhov kub thiab txias ntawm lub roj teeb nce siab tshaj qhov ntsuas kub (~ 130 ° C), PE txheej ntxeem tau ib nrab melts, kaw cov yeeb yaj kiab qhov pores thiab tiv thaiv kev tsiv teb tsaws ntawm ions hauv cov kua electrolyte, thaum PP txheej muab kev txhawb nqa kom tsis txhob sab hauv. luv.Hloov pauv, thermally induced shutdown ntawm LIB kuj tuaj yeem ua tiav los ntawm kev siv cov thermoresponsive PE lossis paraffin wax microspheres ua cov txheej tiv thaiv ntawm lub roj teeb anodes lossis cov khoom sib cais.Thaum lub roj teeb sab hauv qhov ntsuas kub nce mus txog qhov tseem ceeb, cov microspheres yaj thiab coated lub anode/separator nrog ib tug nonpermeable barrier, nres Li-ion thauj thiab kaw lub cell mus tas li (Fig. 5D).
Separators nrog siab thermal stability.Txhawm rau txhim kho thermal stability ntawm cov roj teeb cais, ob txoj hauv kev tau tsim nyob rau ntau xyoo dhau los:
(1) Ceramic-txhim kho cov khoom sib cais, tsim los ntawm cov txheej txheem ncaj qha lossis ntawm qhov chaw loj hlob ntawm cov txheej txheem ceramic xws li SiO2 thiab Al2O3 ntawm cov khoom siv polyolefin uas twb muaj lawm lossis los ntawm muaj cov hmoov ceramic hauv cov ntaub ntawv polymeric (Fig. 5 E), qhia cov ntsiab lus melting siab heev thiab siab txhua yam muaj zog thiab kuj muaj cov thermal conductivity siab.Qee cov khoom sib cais uas tau tsim los ntawm lub tswv yim no tau ua lag luam, xws li Separion (lub npe lag luam).
(2) Hloov cov khoom sib cais los ntawm polyolefin mus rau high-melting kub polymers nrog tsawg shrinkage thaum cua sov, xws li polyimide, cellulose, poly (butylene) terephthalate, thiab lwm yam analogous poly (esters), yog ib tug zoo lub tswv yim rau kev txhim kho thermal stability. ntawm separators (Fig. 5 F).Piv txwv li, polyimide yog ib qho thermosetting polymer dav suav hais tias yog ib qho kev cog lus lwm txoj hauv kev vim tias nws cov thermal stability zoo heev (ruaj khov tshaj 400 ° C), tshuaj lom neeg tsis kam, siab tensile zog, zoo electrolyte wettability, thiab nplaim retardancy (Fig. 5 G) .
Cov pob roj teeb nrog kev ua haujlwm txias.Cov cuab yeej ntsuas hluav taws xob ntsuas hluav taws xob tau siv los ntawm kev khiav ntawm huab cua lossis kua txias tau siv los txhim kho cov roj teeb kev ua haujlwm thiab txo qis kub nce.Tsis tas li ntawd, cov khoom siv theem-hloov xws li paraffin wax tau muab tso rau hauv cov khoom siv roj teeb los ua lub dab dej kub kom tswj tau lawv qhov kub thiab txias, yog li tsis txhob muaj kev kub ntxhov.
Txhawm rau daws cov teeb meem hauv theem 3 (combustion thiab tawg)
Thaum tshav kub kub, oxygen, thiab roj, lub npe hu ua "daim duab peb sab hluav taws," yog cov khoom xyaw tsim nyog rau hluav taws kub.Nrog rau kev sib sau ntawm cov cua sov thiab cov pa tawm thaum lub sij hawm theem 1 thiab 2, cov roj (uas yog, cov hluav taws xob hluav taws xob uas muaj hluav taws kub heev) yuav pib tawg.Txo cov nplaim hluav taws xob ntawm cov kuab tshuaj electrolyte yog qhov tseem ceeb rau kev nyab xeeb ntawm roj teeb thiab ntxiv rau kev siv loj ntawm LIBs.
Nplaim-retardant additives.Kev tshawb fawb loj heev tau mob siab rau kev txhim kho cov nplaim hluav taws kub-retardant additives kom txo cov nplaim taws ntawm cov kua electrolytes.Feem ntau ntawm cov nplaim-retardant additives siv nyob rau hauv cov kua electrolytes yog raws li cov organic phosphorus tebchaw los yog organic halogenated tebchaw.Raws li halogens muaj kev phom sij rau ib puag ncig thiab tib neeg kev noj qab haus huv, cov organic phosphorus tebchaw yog cov neeg sib tw zoo dua li cov nplaim hluav taws kub-retardant additives vim lawv cov nplaim hluav taws kub-retarding muaj peev xwm thiab kev phooj ywg ib puag ncig.Cov organic phosphorus compounds xws li trimethyl phosphate, triphenyl phosphate, bis (2-methoxyethoxy)methylallylphosphonate, tris (2,2,2-trifluoroethyl) phosphite, (ethoxy) pentafluorocyclotriphosphazene, ethylene (ethyl.Fig. 6 A).Cov txheej txheem rau cov nplaim hluav taws xob cuam tshuam ntawm cov phosphorus-muaj cov tebchaw no feem ntau ntseeg tau tias yog cov txheej txheem tshuaj lom neeg radical-scavenging.Thaum lub sij hawm combustion, cov phosphorus-muaj cov molecules tuaj yeem decompose rau phosphorus-muaj cov dawb-radical hom, uas tuaj yeem tshem tawm cov radicals (piv txwv li, H thiab OH radicals) generated thaum lub sij hawm saw cov tshuaj tiv thaiv propagation uas yog lub luag hauj lwm rau tas mus li combustion (Daim duab 6, B thiab C).Hmoov tsis zoo, qhov txo qis hauv cov nplaim taws nrog qhov sib ntxiv ntawm cov phosphorus-muaj cov nplaim hluav taws kub nyhiab los ntawm kev siv hluav taws xob ua haujlwm.Txhawm rau txhim kho qhov kev lag luam tawm no, lwm cov kws tshawb fawb tau ua qee qhov kev hloov kho rau lawv cov qauv molecular: (i) ib nrab fluorination ntawm alkyl phosphates tuaj yeem txhim kho lawv cov kev ruaj ntseg txo thiab lawv cov nplaim hluav taws xob ua haujlwm zoo;(ii) kev siv cov khoom sib txuas muaj ob qho tib si tiv thaiv zaj duab xis-tsim thiab nplaim-retarding zog, xws li bis (2-methoxyethoxy)methylallylphosphonate, qhov twg cov allylic pawg muaj peev xwm polymerize thiab tsim ib tug ruaj khov SEI zaj duab xis ntawm graphite nto, yog li zoo tiv thaiv sab txaus ntshai. tshuaj tiv thaiv;(iii) hloov P(V) phosphate mus rau P(III) phosphites, uas pab txhawb SEI tsim thiab muaj peev xwm ntawm deactivating txaus ntshai PF5 [piv txwv li, tris(2,2,2-trifluoroethyl) phosphite];thiab (iv) hloov organophosphorus additives nrog cyclic phosphazenes, tshwj xeeb tshaj yog fluorinated cyclophosphazene, uas tau txhim kho electrochemical compatibility.
Daim duab 6 Cov tswv yim los daws cov teeb meem hauv theem 3.
(A) Hom qauv molecular ntawm nplaim-retardant additives.(B) Cov txheej txheem rau cov nplaim hluav taws kub nyhiab ntawm cov phosphorus-muaj cov tebchaw no feem ntau ntseeg tau tias yog cov txheej txheem tshuaj lom neeg radical-scavenging, uas tuaj yeem txiav tawm cov kev cuam tshuam ntawm cov saw hluav taws xob ua lub luag haujlwm rau cov tshuaj tiv thaiv combustion hauv cov roj theem.TPP, triphenyl phosphate.(C) Lub sijhawm tua tus kheej (SET) ntawm cov carbonate electrolyte raug txo qis nrog kev sib ntxiv ntawm triphenyl phosphate.(D) Schematic ntawm "ntse" electrospun separator nrog thermal-triggered nplaim-retardant zog rau LIBs.Lub free-standing separator yog tsim los ntawm microfibers nrog ib tug core-plhaub qauv, qhov twg cov nplaim retardant yog cov tub ntxhais thiab cov polymer yog lub plhaub.Thaum lub thermal triggering, lub plhaub polymer melts thiab tom qab ntawd cov nplaim hluav taws kub hnyiab tau tso rau hauv cov electrolyte, yog li muaj txiaj ntsig zoo tiv thaiv hluav taws thiab hlawv ntawm electrolytes.(E) SEM duab ntawm TPP@PVDF-HFP microfibers tom qab etching kom meej meej qhia lawv cov core-plhaub qauv.Scale bar, 5 μm.(F) Cov qauv molecular ntawm chav tsev kub ionic kua siv los ua cov electrolytes nonflammable rau LIBs.(G) Cov qauv molecular ntawm PFPE, ib qho nonflammable perfluorinated PEO analog.Ob pawg methyl carbonate tau hloov kho ntawm cov terminals ntawm polymer chains kom ntseeg tau tias kev sib raug zoo ntawm cov molecules nrog cov roj teeb tam sim no.
Nws yuav tsum raug sau tseg tias ib txwm muaj kev lag luam tawm ntawm qhov txo qis ntawm cov hluav taws xob hluav taws xob thiab kev ua haujlwm ntawm tes rau cov khoom ntxiv uas tau teev tseg, txawm hais tias qhov kev cuam tshuam no tau txhim kho los ntawm cov qauv tsim qauv saum toj no.Lwm lub tswv yim los daws qhov teeb meem no suav nrog kev sib txuas cov nplaim hluav taws hauv lub plhaub tiv thaiv polymer ntawm microfibers, uas tau muab tso ua ke ntxiv los tsim cov khoom sib cais tsis sib xws (Fig. 6D) .Ib qho tshiab electrospun nonwoven microfiber separator nrog thermal-triggered nplaim-retardant zog yog fabricated rau LIBs.Lub encapsulation ntawm cov nplaim retardant nyob rau hauv lub plhaub tiv thaiv polymer tiv thaiv ncaj qha raug hluav taws xob retardant rau electrolyte, tiv thaiv tsis zoo los ntawm cov retardants ntawm lub electrochemical kev ua tau zoo ntawm lub roj teeb (Fig. 6 E).Txawm li cas los xij, yog tias thermal runaway ntawm LIB roj teeb tshwm sim, poly (vinylidenefluoride-hexafluoro propylene) copolymer (PVDF-HFP) plhaub yuav yaj thaum kub nce.Tom qab ntawd lub encapsulated triphenyl phosphate nplaim retardant yuav raug tso tawm rau hauv cov electrolyte, yog li zoo suppressing cov combustion ntawm cov heev flammable electrolytes.
Ib lub tswv yim "salt-concentrated electrolyte" kuj tau tsim los daws qhov teeb meem no.Cov hluav taws tua hluav taws no cov organic electrolytes rau cov roj teeb rechargeable muaj LiN (SO2F) 2 raws li cov ntsev thiab cov nplaim hluav taws nrov ntawm trimethyl phosphate (TMP) ua cov kuab tshuaj ib leeg.Kev tsim tus kheej ntawm qhov muaj zog ntsev-los ntawm inorganic SEI ntawm lub anode yog qhov tseem ceeb rau kev ua haujlwm ruaj khov electrochemical.Lub tswv yim tshiab no tuaj yeem txuas ntxiv mus rau ntau yam ntawm lwm cov nplaim hluav taws thiab tuaj yeem qhib txoj hauv kev tshiab rau kev tsim cov nplaim hluav taws kub nyhiab tshiab rau LIBs nyab xeeb.
Nonflammable kua electrolytes.Ib qho kev daws teeb meem zoo tshaj plaws rau cov teeb meem kev nyab xeeb ntawm electrolyte yuav yog los tsim cov khoom siv hluav taws xob uas tsis muaj hluav taws xob.Ib pawg ntawm nonflammable electrolytes uas tau kawm ntau heev yog ionic kua, tshwj xeeb tshaj yog chav tsev kub ionic kua, uas yog nonvolatile (tsis pom vapor siab tshaj 200 ° C) thiab nonflammable thiab muaj ib tug dav qhov rais qhov rais (Daim duab 6 F) .Txawm li cas los xij, kev tshawb fawb tsis tu ncua tseem yuav tsum tau daws cov teeb meem ntawm qhov muaj peev xwm tsawg uas tshwm sim los ntawm lawv cov viscosity siab, qis Li hloov pauv tus lej, cathodic lossis txo qis qis, thiab cov nqi siab ntawm cov kua ionic.
Tsawg-molecular hnyav hydrofluoroethers yog lwm chav kawm ntawm cov kua electrolytes uas tsis yog-flammable vim lawv qhov siab lossis tsis muaj flash point, nonflammable, tsis tshua muaj qhov nro, tsis tshua muaj viscosity, tsis tshua muaj khov kub, thiab lwm yam.Kev tsim qauv molecular yuav tsum tau ua kom hloov kho lawv cov tshuaj lom neeg kom ua tau raws li cov qauv ntawm cov roj teeb electrolytes.Ib qho piv txwv nthuav uas tau tshaj tawm tsis ntev los no yog perfluoropolyether (PFPE), ib qho perfluorinated polyethylene oxide (PEO) analog uas paub zoo rau nws cov khoom tsis haum (Fig. 6 G) .Ob pawg methyl carbonate raug hloov kho ntawm pawg davhlau ya nyob twg ntawm PFPE chains (PFPE-DMC) kom ntseeg tau tias kev sib raug zoo ntawm cov molecules nrog cov roj teeb tam sim no.Yog li, qhov tsis muaj hluav taws xob thiab thermal stability ntawm PFPEs tuaj yeem txhim kho kev nyab xeeb ntawm LIBs tau zoo thaum nce tus lej hloov hluav taws xob vim yog tus qauv tsim tshwj xeeb molecular.
Theem 3 yog qhov kawg tab sis tshwj xeeb yog theem tseem ceeb rau cov txheej txheem thermal khiav.Nws yuav tsum raug sau tseg tias txawm hais tias kev siv zog loj tau mob siab rau txhawm rau txo cov nplaim taws ntawm lub xeev-ntawm-lub-kos duab ua kua electrolyte, kev siv cov khoom siv hluav taws xob electrolytes uas tsis muaj hluav taws xob qhia tau hais tias muaj kev cog lus zoo.Cov khoom electrolytes feem ntau poob rau hauv ob pawg: inorganic ceramic electrolytes [sulfides , oxides, nitrides , phosphates, thiab lwm yam.] thiab cov khoom polymer electrolytes [kev sib xyaw ntawm Li ntsev nrog polymers, xws li poly (ethylene oxide), polyacrylonitrile, thiab lwm yam.] .Kev siv zog los txhim kho cov khoom electrolytes yuav tsis qhia meej ntawm no, vim tias cov ncauj lus no twb tau sau tseg zoo hauv ntau qhov kev tshuaj xyuas tsis ntev los no.
XOV XWM
Yav dhau los, ntau cov ntaub ntawv tshiab tau tsim los txhim kho roj teeb kev nyab xeeb, txawm hais tias qhov teeb meem tseem tsis tau daws tag nrho.Tsis tas li ntawd, cov txheej txheem ntawm cov teeb meem kev nyab xeeb sib txawv rau txhua qhov sib txawv roj teeb chemistry.Yog li, cov ntaub ntawv tshwj xeeb tsim rau cov roj teeb sib txawv yuav tsum tau tsim.Peb ntseeg tias cov txheej txheem ua tau zoo dua thiab cov ntaub ntawv tsim tau zoo tseem yuav raug tshawb pom.Ntawm no, peb sau ntau cov lus qhia ua tau rau kev tshawb fawb txog kev nyab xeeb roj teeb yav tom ntej.
Ua ntej, nws yog ib qho tseem ceeb rau kev txhim kho nyob rau hauv situ los yog nyob rau hauv operando txoj kev los xyuas thiab saib xyuas cov kev noj qab haus huv nyob rau hauv lub LIBs.Piv txwv li, cov txheej txheem thermal runaway yog ze ze rau qhov kub thiab txias los yog siab nce hauv LIBs.Txawm li cas los xij, qhov ntsuas kub ntawm cov roj teeb hauv cov roj teeb yog qhov nyuaj, thiab cov txheej txheem yuav tsum tau ua kom pom tseeb cov txiaj ntsig ntawm electrolytes thiab electrodes, nrog rau cov khoom sib cais.Yog li, muaj peev xwm ntsuas cov ntsuas no rau cov khoom sib txawv yog qhov tseem ceeb rau kev kuaj mob thiab yog li tiv thaiv kev nyab xeeb ntawm roj teeb.
Lub thermal stability ntawm cov khoom sib cais yog qhov tseem ceeb rau kev nyab xeeb ntawm roj teeb.Cov polymers tshiab tsim nrog cov ntsiab lus siab melting yog qhov ua tau zoo ntawm kev ua kom cov thermal kev ncaj ncees ntawm cov khoom sib cais.Txawm li cas los xij, lawv cov khoom siv kho tshuab tseem qis dua, txo lawv txoj kev ua tau zoo thaum lub sijhawm sib dhos roj teeb.Tsis tas li ntawd, tus nqi kuj yog ib qho tseem ceeb uas yuav tsum tau txiav txim siab rau kev siv tswv yim.
Txoj kev loj hlob ntawm cov khoom electrolytes zoo li yog qhov kev daws teeb meem kawg rau cov teeb meem kev nyab xeeb ntawm LIBs.Cov khoom siv electrolyte yuav txo tau qhov muaj peev xwm ntawm roj teeb sab hauv luv luv, nrog rau kev pheej hmoo ntawm hluav taws kub thiab tawg.Txawm hais tias kev siv zog zoo tau mob siab rau kev nce qib ntawm cov khoom siv electrolytes, lawv qhov kev ua tau zoo txuas ntxiv mus deb ntawm cov kua electrolytes.Composites ntawm inorganic thiab polymer electrolytes qhia tau hais tias muaj peev xwm, tab sis lawv xav tau kev tsim thiab kev npaj.Peb hais ntxiv tias kev tsim kom zoo ntawm cov khoom siv hluav taws xob-polymer cuam tshuam thiab kev tsim vaj tsev ntawm lawv cov kev sib dhos yog qhov tseem ceeb rau kev thauj mus los Li-ion zoo.
Nws yuav tsum tau muab sau tseg tias cov kua electrolyte tsis yog tib lub roj teeb uas yog combustible.Piv txwv li, thaum LIBs raug nqi ntau heev, cov khoom siv lithiated anode combustible (piv txwv li, lithiated graphite) kuj yog ib qho kev txhawj xeeb loj.Cov nplaim hluav taws kub hnyiab uas tuaj yeem tiv thaiv hluav taws zoo ntawm cov khoom siv hauv lub xeev yog qhov xav tau los ua kom lawv muaj kev nyab xeeb.Cov nplaim hluav taws kub hnyiab tau tuaj yeem sib xyaw nrog cov graphite hauv daim ntawv ntawm polymer binders lossis cov txheej txheem ua haujlwm.
Roj teeb kev nyab xeeb yog ib qho teeb meem nyuaj thiab sophisticated.Lub neej yav tom ntej ntawm lub roj teeb kev nyab xeeb hu rau kev siv zog ntau dua hauv cov kev tshawb fawb mechanistic rau kev nkag siab tob ntxiv nrog rau cov txheej txheem kev ua tau zoo dua qub, uas tuaj yeem muab cov ntaub ntawv ntxiv los qhia cov ntaub ntawv tsim.Txawm hais tias qhov Kev Ntsuam Xyuas no tsom rau cov khoom siv-theem kev nyab xeeb, nws yuav tsum tau muab sau tseg tias yuav tsum muaj kev sib koom ua ke ntxiv los daws qhov teeb meem kev nyab xeeb ntawm LIBs, qhov twg cov khoom siv, cov khoom siv ntawm tes thiab hom, thiab cov roj teeb module thiab cov pob khoom ua si sib npaug los ua kom cov roj teeb txhim khu kev qha ua ntej. lawv muab tso rau tom khw.
CEEB TOOM thiab sau ntawv
Kai Liu, Yayuan Liu, DingchangLin, Allen Pei, Yi Cui, Khoom siv rau lithium-ion roj teeb kev nyab xeeb, ScienceAdvances, DOI: 10.1126/sciadv.aas9820
Post lub sij hawm: Jun-05-2021
