Li Tingting, ZHANG Yang, CHEN Jiahang, MIN Yulin, WANG Jiulin. Flexible Binder rau S@pPAN Cathode ntawm Lithium Sulfur Battery. Phau ntawv Journal of Inorganic Materials, 2022, 37(2): 182-188 DOI:10.15541/jim20210303
Abstract
Sulfurized pyrolyzed poly (acrylonitrile) (S@pPAN) sib xyaw ua cov khoom siv cathode ntawm Li-S roj teeb paub txog cov khoom siv hloov pauv cov tshuaj tiv thaiv tsis muaj kev sib cais ntawm polysulfides. Txawm li cas los xij, nws qhov chaw thiab cov yam ntxwv cuam tshuam cuam tshuam rau electrochemical kev ua tau zoo, thiab tseem muaj qhov pom tseeb ntim hloov thaum lub sij hawm electrochemical cycling. Nyob rau hauv txoj kev tshawb no, ib leeg-walled carbon nanotubes (SWCNT) thiab sodium carboxymethyl cellulose (CMC) tau siv los ua binder rau S@pPAN cathode los tswj qhov nto ntawm S@pPAN thiab txo cov ntim hloov thaum lub sij hawm them thiab tawm. Ntawm qhov ceev tam sim no ntawm 2C, lub peev xwm tuav tau ntawm cov roj teeb tom qab 140 lub voj voog yog 84.7 feem pua, thiab lub peev xwm tshwj xeeb ntawm 1147 mAh∙g-1 tseem tuaj yeem khaws cia ntawm qhov ceev tam sim no ntawm 7C. Lub zog tensile kawg rau zaj duab xis ntawm cov khoom sib xyaw ua ke nce los ntawm 41 zaug tom qab ntxiv SWCNT, thiab cov ntaub ntawv sib xyaw tau lees paub qhov ruaj khov electrode interface thaum lub sijhawm ua haujlwm, yog li txhim kho lub voj voog ruaj khov ntawm cov roj teeb lithium-sulfur.
Ntsiab lus:lithium-sulfur roj teeb, S@pPAN cathode, sodium carboxymethyl cellulose; binder, ruaj khov interface
Cov roj teeb lithium-ion ib txwm muaj qhov zoo ntawm cov txheej txheem kev npaj yooj yim thiab siv tau yooj yim, tab sis cov teeb meem ntawm lub zog tsis tshua muaj zog (feem ntau tsawg dua 250 Wh∙kg-1) thiab tus nqi siab tseem tseem ceeb. Cov roj teeb lithium-sulfur muaj ntau dua theoretical tshwj xeeb zog ceev (2600 Wh∙kg-1), thiab raug suav hais tias yog cov tiam tom ntej ntawm cov roj teeb uas siv tau thib ob uas muaj peev xwm txhim kho tau zoo. Ntxiv mus, elemental sulfur muaj qhov zoo ntawm kev khaws cia ntau, tus nqi qis, thiab lub peev xwm theoretical ntawm 1672 mAh·g-1. Txawm li cas los xij, cov khoom siv tshuaj sulfur zoo electrode yuav muaj qhov hloov pauv loj (kwv yees li 80 feem pua) thiab cov hmoov electrode thaum lub sij hawm them nyiaj thiab tso tawm, ua rau lub neej luv luv. Thiab nws yuav tsim cov polysulfides soluble, uas ua rau cov nyhuv shuttle, uas thaum kawg ua rau muaj teeb meem xws li kev siv cov khoom siv qis thiab tsis zoo rau lub voj voog ntawm lub roj teeb. Txhawm rau txo qhov cuam tshuam ntawm kev cuam tshuam ntawm kev ua haujlwm ntawm lub roj teeb, cov kws tshawb fawb tau tsim ntau cov khoom siv sulfur-based composite cathode los txhim kho kev ua haujlwm ntawm lithium-sulfur roj teeb. Xws li cov khoom siv carbon-sulfur composite, conductive polymers thiab cov ntaub ntawv sib xyaw tsim los ntawm cov hlau oxides thiab sulfur. Ib leeg-walled carbon nanotubes (SWCNTs) yog cov khoom siv dav dav nrog qhov zoo ntawm qhov ntom ntom, lub teeb yuag, thiab hluav taws xob zoo. Nyob rau hauv txoj kev tshawb no, sodium carboxymethyl cellulose tau hloov kho los ntawm kev ntxiv SWCNT los txhim kho lub toughness thiab qhov kawg tensile lub zog ntawm lub binder. Daim ntawv thov ntawm no composite binder (cim raws li SCMC) nyob rau hauv lithium-sulfur roj teeb nrog S@pPAN raws li cov khoom cathode tuaj yeem txhim kho lub voj voog ruaj khov ntawm lub roj teeb.
Txoj kev sim
1.1 Kev npaj khoom siv
Ntsuas ib qho nyiaj ntawm polyacrylonitrile (Mw{{0}}}.5 × 105, Aldrich) thiab cov ntsiab lus sulfur raws li qhov sib piv loj ntawm 1:8, ntxiv ib qho tsim nyog ntawm cov ethanol li dispersant, thiab sib tov sib npaug rau hauv lub thawv ntim agate pob zeb. Tom qab lub pob milling rau 6 teev, nws tau qhuav hauv qhov cub tawg ntawm 60 degree. Tom qab ziab, grind lub block sib tov zoo. Tom qab ntawd ib qho nyiaj ntawm cov hmoov sib tov tau hnyav thiab muab tso rau hauv lub nkoj quartz, thiab qhov kub thiab txias tau nce mus rau 300 degree hauv lub tshuab hluav taws xob hauv lub tshuab hluav taws xob nyob rau hauv qhov chaw tiv thaiv nitrogen, thiab khaws cia rau 6.5 teev kom tau txais S@pPAN cov hmoov dub nrog cov sulfur pawg ntawm 41 feem pua. Qhov hnyav 20 mg SWCNT rau hauv ib lub raj mis, thiab tom qab ntawd ntxiv 0.5 mg·mL-1 sodium dodecylbenzenesulfonate (SDBS). Tom qab kev kho ultrasonic rau 10 teev, CMC (Mw=7 × 105, Aldrich) tau ntxiv rau SWCNT ncua kev kawm (qhov loj piv ntawm CMC thiab SWCNT yog 2: 1) thiab nplawm rau 2 teev kom tau txais SCMC, thiab nws cov ntsiab lus khoom loj feem yog 1 feem pua .Ntxiv rau, CMC siv raws nraim li kev kho mob saum toj no. Dissolve CMC nyob rau hauv dej deionized, qhov loj feem ntawm CMC yog 1 feem pua, thiab cov qauv yog sau npe raws li CMCP.
1.2 Electrode npaj thiab roj teeb sib dhos
S@pPAN, Super P thiab bonding slurry (SCMC lossis CMCP) tau hnyav raws li qhov sib piv ntawm 8: 1: 1. Muab tso rau hauv lub tank polytetrafluoroethylene rau pob milling rau 2 teev, thiab qhov loj ntawm cov slurry bonded yog xam raws li qhov loj ntawm cov khoom theem. Cov slurry tau coated rau ntawm cov pa roj carbon-coated aluminium ntawv ci nrog cov ntawv thov zaj duab xis, thiab tom qab ziab hauv chav sov, nws raug txiav rau hauv ϕ12 mm discs nrog microtome, thiab qhuav hauv qhov cub tawg ntawm 7 0 degree rau 6 teev. Tom qab ua ntej ziab, cov ncej ncej tau ua tiav nrog cov ntsiav tshuaj xovxwm nyob rau hauv lub siab ntawm 12 MPa kom txo cov thickness ntawm tus ncej thiab ua rau kom lub compaction ceev ntawm tus ncej, thiab ces mus txuas ntxiv nqus qhuav ntawm 70 degree rau 6 teev. Tom qab qhov kub ntawm lub tshuab nqus tsev vacuum poob mus rau hauv chav tsev kub, cov ncej ncej tau sai sai hloov mus rau lub hnab looj tes rau qhov hnyav thiab tso tseg. Cov khoom nquag thauj khoom ib cheeb tsam ntawm cathode hauv txoj kev tshawb no yog kwv yees li 0.6 mg∙cm-2. Cov electrodes raws li SCMC thiab CMCP yog denoted li S@pPAN/SCMC thiab S@pPAN/CMC, feem.
1.3 Kev xeem Electrochemical kev ua tau zoo
A 2016- hom khawm roj teeb tau sib sau ua ke hauv qhov kev txiav txim ntawm cov ntaub ntawv zoo electrode, daim ntawv zoo electrode, cais, thiab lithium ntawv. Cov electrolyte yog 1 mol L-1 LiPF6 ethylene carbonate (EC) / dimethyl carbonate (DMC) (ntim piv 1: 1) tov ntxiv rau pawg pawg 10 feem pua fluoroethylene carbonate (10 feem pua FEC), Lub diaphragm yog polyethylene (PE) diaphragm.
Siv Xinwei roj teeb xeem system los ua qhov kev ntsuas tam sim no thiab tso tawm ntawm cov roj teeb sib dhos. Lub roj teeb tau tso cai sawv ntsug rau 4 teev ua ntej kev caij tsheb kauj vab kom nkag mus rau hauv cov khoom sib cais thiab cov electrodes nrog cov electrolyte. Tus nqi hluav taws xob txiav tawm qhov hluav taws xob muaj nyob ntawm 1.0 mus rau 3.0 V, thiab qhov ntsuas kub tsis tu ncua ntawm 25 degree tau khaws cia thaum caij tsheb kauj vab. Kev ntsuas lub voj voog mus sij hawm ntev tau ua tiav ntawm 2C tam sim no qhov ceev, thiab qhov kev ua haujlwm ntawm lub roj teeb tau sim ntawm 0.5C, 1C, 3C, 5C, thiab 7C tam sim no ntom ntom. Cyclic voltammetry (CV) tau ua nyob rau ntawm CHI 760E electrochemical workstation nrog tus nqi scan ntawm 1 mV s -1. Lub peev xwm tshwj xeeb yog xam raws li cov khoom siv tshuaj sulfur.
1.4 Cov yam ntxwv ntawm lub cev
X-ray photoelectron spectroscopy (XPS) tau siv los tshuaj xyuas cov ntsiab lus ntawm cov ntawv lithium tom qab lub roj teeb caij tsheb kauj vab, thiab cov qauv npaj tau ua tiav hauv lub hnab looj tes. XRD spectrum ntawm S@pPAN cov khoom raug kuaj los ntawm X-ray diffractometer (XRD).
Qhov kev ntxhov siab-txheej nkhaus ntawm cov nplaum tau sim nrog lub ntsuas kub ntsuas kub (DMA Q850). Cov txheej txheem kev npaj ua qauv yog raws li nram no: poob CMCP thiab SCMC rau saum npoo ntawm lub tiaj tiaj thiab huv si polytetrafluoroethylene phaj, muab tso rau hauv qhov cub tawg ntawm 55 degree rau 8 h los ua ib zaj duab xis, thiab txiav nws mus rau hauv ib daim hlab rau kev ntsuam xyuas, raws li CMC zaj duab xis thiab SCMC daim nyias nyias.
Lub voj voog electrodes raug ntxuav peb zaug nrog qhov tsim nyog ntawm DMC hnyav nyob rau hauv ib lub hnab looj tes kom tshem tawm cov electrolyte seem ntawm qhov chaw, thiab qhuav lawm. Lub morphology ntawm cov qauv tau pom los ntawm electron microscopy (SEM).
Ntau lithium ionCov khoom siv roj teeblos ntawmTOB New Energy
