Sulfur-based all-solid-state batteries yuav tsum tau hloov cov roj teeb lithium-ion tam sim no vim lawv txoj kev nyab xeeb zoo dua. Txawm li cas los xij, nyob rau hauv cov txheej txheem kev npaj ntawm tag nrho cov khoom-lub xeev roj teeb slurry, muaj incompatible polarities ntawm hnyav, binder thiab sulphide electrolyte, yog li tsis muaj txoj kev mus cuag loj-scale ntau lawm tam sim no. Tam sim no, kev tshawb fawb ntawm tag nrho cov khoom-lub xeev cov roj teeb feem ntau yog ua los ntawm kev ntsuas ntsuas, thiab lub ntim ntawm lub roj teeb kuj me me. Qhov loj-scale ntau lawm ntawm tag nrho cov-khoom-lub xeev roj teeb yog tseem mus rau cov uas twb muaj lawm cov txheej txheem ntau lawm, uas yog, cov active tshuaj yog npaj rau hauv slurry thiab ces coated thiab qhuav, uas muaj peev xwm muaj tsawg nqi thiab ntau dua efficiency.

ib tug

Teeb meem ntsib

Yog li ntawd, nws yog ib qho nyuaj rau nrhiav tau haum polymer binder thiab hnyav los pab txhawb cov kua. Feem ntau cov sulfur-based khoom electrolytes tuaj yeem yaj hauv cov kuab tshuaj polar, xws li NMP peb tam sim no siv. Yog li kev xaiv cov kuab tshuaj tsuas tuaj yeem ua rau tsis muaj polarity lossis tsis muaj zog polarity ntawm cov kuab tshuaj, uas txhais tau hais tias kev xaiv ntawm cov ntaub ntawv tseem ceeb kuj yog nqaim – feem ntau ntawm cov polar functional pawg ntawm cov polymer tsis tuaj yeem siv!

Qhov no tsis yog qhov teeb meem phem tshaj plaws. Nyob rau hauv cov nqe lus ntawm polarity, cov binders uas yog sib xws nrog cov kuab tshuaj thiab sulfide electrolytes yuav ua rau kom txo cov kev sib raug zoo ntawm aggregates thiab active tshuaj thiab electrolytes, uas yuav undoubtedly ua rau huab electrode impedance thiab ceev ceev decay, uas yog heev detrimental rau roj teeb kev ua tau zoo.

Txhawm rau ua kom tau raws li qhov xav tau saum toj no, peb cov khoom tseem ceeb (binder, hnyav, electrolyte) tuaj yeem raug xaiv, tsuas yog cov tsis muaj polar lossis tsis muaj zog polar solvents, xws li para-(P) xylene, toluene, n-hexane, anisole, thiab lwm yam. ., siv tsis muaj zog polar polymer binder, xws li butadiene roj hmab (BR), styrene butadiene roj hmab (SBR), SEBS, polyvinyl chloride (PVC), nitrile roj hmab (NBR), silicone roj hmab thiab ethyl cellulose, thiaj li ua tau raws li qhov yuav tsum tau ua. .

ob

Nyob rau hauv situ polar – non-polar conversion tswvyim

Nyob rau hauv daim ntawv no, ib hom tshiab ntawm binder yog qhia, uas yuav hloov lub polarity ntawm electrode thaum machining los ntawm kev tiv thaiv-de-tiv thaiv chemistry. Lub ncov qaumteb qabteb functional pawg ntawm no binder muaj kev tiv thaiv los ntawm non-polar tert-butyl functional pawg, kom ntseeg tau tias cov binder tuaj yeem sib phim nrog sulfide electrolyte (qhov no LPSCl) thaum lub sij hawm npaj cov electrode paste. Tom qab ntawd los ntawm kev kho cua sov, uas yog cov txheej txheem ziab ntawm cov electrode, tert-butyl ua haujlwm pab pawg ntawm cov ntaub ntawv polymer tuaj yeem ua rau thermal cais, kom ua tiav lub hom phiaj ntawm kev tiv thaiv, thiab thaum kawg tau txais cov polar binder. Saib daim duab A.

Daim duab

BR (butadiene roj hmab) raug xaiv los ua polymer binder rau sulfide all-solid-state roj teeb los ntawm kev sib piv cov khoom siv hluav taws xob thiab hluav taws xob ntawm cov electrode. Ntxiv rau kev txhim kho cov khoom siv hluav taws xob thiab hluav taws xob hluav taws xob ntawm tag nrho cov khoom siv-lub xeev cov roj teeb, qhov kev tshawb fawb no qhib txoj hauv kev tshiab rau polymer binder tsim, uas yog kev tiv thaiv-de-tiv thaiv-tshuaj lom neeg txoj hauv kev kom cov electrodes hauv lub xeev tsim nyog thiab xav tau ntawm txawv theem ntawm electrode manufacturing.

Tom qab ntawd, polytert-butylacrylate (TBA) thiab nws cov block copolymer, polytert-butylacrylate – b-poly 1, 4-butadiene (TBA-B-BR), uas nws carboxylic acid ua haujlwm pab pawg raug tiv thaiv los ntawm cov pab pawg thermolyzed T-butyl, raug xaiv hauv qhov kev sim. Qhov tseeb, TBA yog qhov ua ntej ntawm PAA, uas yog feem ntau siv hauv cov roj teeb lithium ion tam sim no, tab sis tsis tuaj yeem siv rau hauv cov roj ntsha sulfide-raws li tag nrho cov khoom lithium vim nws cov polarity mismatch. Lub zog polarity ntawm PAA tuaj yeem ua rau muaj zog nrog sulfide electrolytes, tab sis nrog kev tiv thaiv carboxylic acid ua haujlwm pab pawg T-butyl, polarity ntawm PAA tuaj yeem txo qis, tso cai rau nws yaj hauv cov kuab tshuaj tsis muaj polar lossis tsis muaj zog polar. Tom qab kev kho cua sov, pawg t-butyl ester yog decomposed kom tso tawm isobutene, uas ua rau tsim carboxylic acid, raws li qhia nyob rau hauv daim duab B. Cov khoom ntawm ob polymer deprotected yog sawv cev los ntawm (deprotected) TBA thiab (deprotected) TBA- B-BR.

Daim duab

Thaum kawg, cov paA-zoo li binder tuaj yeem sib raug zoo nrog NCM, thaum tag nrho cov txheej txheem tshwm sim hauv qhov chaw. Nws yog to taub hais tias qhov no yog thawj zaug uas nyob rau hauv situ polarity conversion scheme tau siv nyob rau hauv tag nrho cov-solid-state lithium roj teeb.

Raws li qhov ntsuas kub ntawm kev kho cua sov, tsis muaj qhov pom tseeb poob tau pom ntawm 120 ℃, thaum cov khoom sib thooj ntawm butyl pawg tau ploj tom qab 15h ntawm 160 ℃. Qhov no qhia tau hais tias muaj qee qhov kub ntawm qhov uas butyl tuaj yeem raug tshem tawm (hauv kev tsim khoom tiag tiag, lub sijhawm kub no ntev dhau lawm, txawm tias muaj qhov kub thiab txias los yog qhov xwm txheej los txhim kho cov khoom siv tau zoo xav tau kev tshawb fawb thiab kev sib tham ntxiv). Ft-ir cov txiaj ntsig ntawm cov ntaub ntawv ua ntej thiab tom qab deprotection kuj qhia tau tias cov khoom siv electrolyte tsis cuam tshuam nrog cov txheej txheem deprotection. Cov nplaum zaj duab xis tau ua nrog cov nplaum ua ntej thiab tom qab kev tiv thaiv, thiab qhov tshwm sim tau pom tias cov nplaum nplaum tom qab deprotection muaj zog adhesion nrog cov kua dej. Txhawm rau ntsuas qhov sib xyaw ua ke ntawm cov ntawv khi thiab electrolyte ua ntej thiab tom qab kev tiv thaiv, XRD thiab Raman tsom xam tau ua tiav, thiab cov txiaj ntsig tau pom tias LPSCl cov khoom electrolyte muaj kev sib raug zoo nrog cov ntaub ntawv soj ntsuam.

Tom ntej no, ua lub roj teeb tag nrho-lub xeev thiab saib seb nws ua haujlwm li cas. Siv NCM711 74.5% / LPSCL21.5% / SP2% / binder 2%, lub zog stripping ntawm ncej ntawv qhia tau hais tias lub zog stripping yog qhov loj tshaj plaws thaum siv binder tBA-B-BR (raws li qhia hauv daim duab 1). Lub caij no, lub sijhawm stripping kuj muaj feem cuam tshuam rau lub zog stripping. TBA electrode daim ntawv deprotected yog nkig thiab yooj yim rau tawg, yog li TBA-B-BR nrog zoo saj zawg zog thiab siab tev lub zog raug xaiv raws li lub ntsiab binder los ntsuam xyuas lub roj teeb kev ua tau zoo.

Daim duab 1. Peel lub zog nrog cov binders sib txawv

Lub binder nws tus kheej yog ionic insulating. Txhawm rau kawm txog cov txiaj ntsig ntawm kev sib ntxiv ntawm binder ntawm ionic conductivity, ob pawg kev sim tau ua, ib pab pawg muaj 97.5% electrolyte + 2.5% binder thiab lwm pab pawg uas tsis muaj binder. Nws tau pom tias ionic conductivity tsis muaj binder yog 4.8 × 10-3 SCM-1, thiab cov conductivity nrog binder kuj yog 10-3 qhov kev txiav txim ntawm qhov loj. Electrochemical stability ntawm TBA-B-BR tau ua pov thawj los ntawm CV test.

peb

Ib nrab roj teeb thiab kev ua haujlwm puv roj teeb

Ntau qhov kev ntsuam xyuas sib piv qhia tau hais tias cov ntaub ntawv tsis muaj kev tiv thaiv tau zoo dua adhesion thiab tsis cuam tshuam rau kev tsiv teb tsaws ntawm lithium ions. Siv cov ntawv sib txawv ua ib nrab ntawm tes los ntsuam xyuas cov khoom siv hluav taws xob, ntau yam kev sim ib nrab ntawm tes raws li kev sib xyaw nrog cov ntaub ntawv zoo, tsis muaj binder ntawm cov khoom electrolyte thiab Li – Hauv cov electrode ntawm ib qho kev sim, tsis sib xyaw nrog cov khoom hauv cov khoom electrolyte, los ua pov thawj tias qhov sib txawv ntawm lub anode binder. Nws cov txiaj ntsig electrochemical tau pom hauv daim duab hauv qab no:

Daim duab

Hauv daim duab saum toj no: a. yog ib nrab-cell voj voog kev ua tau zoo ntawm cov sib txawv binders thaum qhov ceev ntawm qhov zoo nto yog 8mg / cm2, thiab B yog ib nrab-cell voj voog kev ua tau zoo ntawm cov binders sib txawv thaum qhov ceev ntawm qhov zoo nto yog 16mg / cm2. Nws tuaj yeem pom los ntawm cov txiaj ntsig saum toj no uas (tsis muaj kev tiv thaiv) TBA-B-BR muaj qhov ua tau zoo ntawm lub roj teeb lub voj voog ua haujlwm zoo dua li lwm cov ntawv khi, thiab daim duab voj voog yog piv nrog daim duab tev lub zog, uas qhia tau hais tias cov khoom siv ntawm cov ncej ua si. lub luag haujlwm tseem ceeb hauv kev ua haujlwm ntawm lub voj voog kev ua haujlwm.

Daim duab

Daim duab sab laug qhia EIS ntawm NCM711 / Li-IN ib nrab ntawm tes ua ntej lub voj voog, thiab daim duab sab xis qhia EIS ntawm ib nrab ntawm tes tsis muaj lub voj voog ntawm 0.1c rau 50 lub lis piam. EIS ntawm ib nrab ntawm tes siv (tsis tiv thaiv) TBA-B-BR thiab BR binder feem. Nws tuaj yeem xaus lus los ntawm EIS daim duab raws li hauv qab no:

1. Txawm tias muaj pes tsawg lub voj voog, cov electrolyte txheej RSE ntawm txhua lub roj teeb yog nyob ib ncig ntawm 10 ω cm2, uas sawv cev rau qhov ntim tsis kam ntawm electrolyte LPSCl 2. Tus nqi hloov pauv impedance (RCT) nce thaum lub voj voog, tab sis qhov nce ntawm RCT siv. BR binder tau nce siab dua qhov uas siv tBA-B-BR binder. Nws tuaj yeem pom tias kev sib txuas ntawm cov tshuaj nquag siv BR binder tsis muaj zog heev, thiab muaj qhov xoob ntawm lub voj voog.

Daim duab

SEM tau siv los soj ntsuam cov ntu ntu ntawm cov ncej hauv ntau lub xeev, thiab cov txiaj ntsig tau pom hauv daim duab saum toj no: a. Tba-b-br ua ntej kev ncig (deprotection); B. ua ntej ncig BR; C. TBA-B-BR tom qab 25 lub lis piam (deprotection); D. tom qab 25 lub lis piam BR;

Lub voj voog ua ntej tag nrho cov electrodes tuaj yeem pom kev sib raug zoo ntawm cov khoom nquag, tsuas tuaj yeem pom qhov me me, tab sis tom qab 25 lub lis piam lub voj voog, tuaj yeem pom qhov kev hloov pauv, siv hauv c (tawm) cov koom tes – b – qhov zoo ntawm BR feem ntau cov khoom. los yog tsis muaj kab nrib pleb, thiab siv cov electrode kev ua ntawm BR binder particles muaj ntau cov kab nrib pleb nyob rau hauv nruab nrab, Raws li qhia nyob rau hauv lub daj cheeb tsam ntawm D, ntxiv rau, electrolyte thiab NCM hais yog ntau sib cais, uas yog ib qho tseem ceeb vim li cas rau roj teeb. kev ua haujlwm attenuation.

Daim duab

Thaum kawg, kev ua tau zoo ntawm tag nrho cov roj teeb raug txheeb xyuas. Qhov zoo electrode NCM711 / tsis zoo electrode graphite tuaj yeem ncav cuag 153mAh / g hauv thawj lub voj voog thiab tuav 85.5% tom qab 45 lub voj voog.

plaub

Cov ntsiab lus luv luv

Nyob rau hauv xaus, nyob rau hauv tag nrho cov-solid-state lithium roj teeb, khoom sib cuag ntawm active tshuaj, siab mechanical zog thiab interface stability yog qhov tseem ceeb tshaj plaws kom tau txais kev ua tau zoo electrochemical.