Liquid electrolyte yog dab tsi?
Ua kua electrolyte
(1) Cov tshuaj muaj pes tsawg leeg Cov kua electrolyte kuj hu ua cov tshuaj electrolyte. Nws yog ib qho uas nquag siv organic kua electrolyte hauv lithium - ion roj teeb, los yog hu ua non-aqueous kua electrolyte. Organic kua electrolyte yog tsim los ntawm lithium ntsev, organic solvent, thiab additives.
① Lithium ntsev: feem ntau muab cov ions conductive. Lithium hexafluorophosphate yog cov lithium ntsev ntau tshaj plaws hauv kev lag luam lithium- ion roj teeb. Pure LiPF6 yog cov dawb crystalline hmoov, soluble hauv cov kuab tshuaj organic xws li qis -alkyl ethers, nitriles, pyridine esters, ketones, thiab cawv, tab sis sparingly soluble hauv organic solvents xws li alkanes thiab benzene. LiPF6 electrolyte muaj cov conductivity siab; ntawm 20 degree, conductivity ntawm EC + DMC (ntim piv 1: 1) tuaj yeem ncav cuag 10 × 10-²S / cm. Cov conductivity feem ntau ncav cuag nws qhov siab tshaj plaws thaum cov electrolyte concentration yog ze rau 1mol / L. LiPF6 muaj qhov ruaj khov electrochemical kev ua tau zoo thiab tsis corrode cov khoom tam sim no. Txawm li cas los xij, LiPF6 tsis zoo thermal stability thiab decomposes yooj yim hauv dej, yuav tsum tau tswj nruj me ntsis ntawm cov dej noo ib puag ncig thaum npaj thiab siv.
② Organic kuab tshuaj: Lawv lub luag haujlwm tseem ceeb yog kom yaj cov ntsev lithium, ua kom cov lithium ntsev electrolyte tsim cov ions conductive.
Feem ntau siv cov kuab tshuaj muaj xws li propylene carbonate, dimethyl carbonate, thiab diethyl carbonate.
Organic kuab tshuaj feem ntau yog xaiv rau lawv qhov siab dielectric tas li thiab viscosity tsawg. Ib qho dielectric ntau dua ua rau cov ntsev lithium yooj yim rau yaj thiab sib cais; qis viscosity ua rau kom ceev ion migration. Txawm li cas los xij, qhov tseeb, cov kuab tshuaj nrog cov dielectric siab tsis tu ncua muaj cov viscosity siab, thiab cov kuab tshuaj uas tsis muaj viscosity muaj cov dielectric tsis tu ncua. Yog li ntawd, nws yog ib qho nyuaj rau ib qho hnyav ib txhij ua tau raws li tag nrho cov kev cai no. Lithium-Ion roj teeb feem ntau siv cov khoom sib xyaw ntawm cov kuab tshuaj organic nrog cov dielectric siab thiab cov uas tsis muaj viscosity los them rau qhov tsis txaus ntawm txhua qhov khoom. Piv txwv li, EC carbonates muaj cov dielectric siab tsis tu ncua, uas muaj txiaj ntsig zoo rau lithium ntsev dissociation, thaum DMC, DEC, thiab EMC carbonates muaj cov viscosity tsawg, uas pab txhim kho kev tsiv teb tsaws ntawm lithium ions.
③ Additives: Lawv feem ntau ua lub luag haujlwm hauv kev txhim kho thiab txhim kho cov hluav taws xob thiab kev nyab xeeb ntawm electrolyte. Feem ntau hais lus, additives muaj peb lub luag haujlwm tseem ceeb: aa Txhim kho kev ua haujlwm ntawm SEI membrane, xws li los ntawm kev ntxiv vinylene carbonate (VC), vinyl sulfite (ES), thiab SO2; b. Tiv thaiv kom tsis txhob overcharging (los ntawm kev ntxiv biphenyl) thiab tshaj - tso tawm; c. Cov nplaim hluav taws kub hnyiab tuaj yeem tiv thaiv lub roj teeb los ntawm kev kub hnyiab lossis tawg hauv cov cua kub dhau, xws li ntxiv cov nplaim hluav taws xob halogenated, phosphorus-raws li nplaim hluav taws kub, thiab cov nplaim hluav taws sib xyaw; d. Txo cov kab dej thiab HF cov ntsiab lus hauv cov electrolyte.
