Synthesis And Inoic Conductivity Properties Of Comb-like Poly(Methacrylate) Solid Polymer Electrolyte

In recent years, lithium-ion batteries are playing a key role in portable electrochemicaldevices such as cameras, laptops and so on, due to their safety performance, high specificenergy and energy density. However, the problems of most lithium-ion batteries composed oforganic solvents as liquid electrolyte, are solvents leakage and volatility, leading to safetydefect. And Gel polymer electrolytes have bad mechanical strength and thermostability. theseproblems may be overcome by using solid polymer electrolytes(SPEs), which have beenattracted much attention nowadays.A series of novel comb-like polymers with different monomers ratio were synthesized bysolution polymerization with methyl methacrylate and poly(ethylene glycol) methyl ethermethacrylate as monomers. The microstructure of novel comb-like polymers were confirmedby FTIR and1H-NMR. The results of DSC and XRD indicated that novel comb-like polymerswere almost amorphous at room temperature. The novel comb-like polymers also hadexcellent thermal stability, which was verified by TG.Novel comb-like polymers-based solid polymer electrolytes incorporated with LiClO4were prepared by solution casting technique. The ionic conductive mechanism,electrochemical properties and mechanical properties have been investigated. We found thatsolid polymer electrolytes(SPEs) existed interactions not only between ether and salt but alsobetween carboxyl and salt. In addition, The LiClO4could dissolve in the comb-like polymerswell and anion mainly presented in terms of free ion, when the LiClO4concentration less than24wt%. The ionic conductivity of SPEs will improve with the salt concentration increasing.When the LiClO4concentration is24wt%, the maximum ionic conductivity of SPE-9-1andSPE-12-1reached7.03×10-5S/cm,6.82×10-5S/cm at30℃, respectively. The ionicconductivity would decrease with the salt concentration increasing more. The temperaturedependence on ionic conductivity of SPEs obeyed VTF rule. The linear sweep voltagetechnique indicated that electrochemical stability windows of SPE-9-1-24%was about4.1V,which was consistent with the result of cyclic voltammetry technique. The initialdecomposition temperature of SPEs was around240℃, which showed SPEs having excellent thermal stability. The comb-like polymer containing polar MMA monomer do good toimprove the mechanical properties of solid polymer electrolytes.A series of novel comb-like polymers with different PEO side chain length weresynthesized by solution polymerization with methyl methacrylate and poly(ethylene glycol)methyl ether methacrylate as monomers. The structure of comb-like polymers were verifiedby FTIR and1H-NMR. DSC and TG were used to characterized the thermodynamicproperties of comb-like polymers.Solid polymer electrolytes were prepared by solution casting technique. And theelectrochemical properties and mechanical properties have been investigated. We found thatPEO side chain would improve the ionic conductivity of polymer electrolytes. the maximumionic conductivity of SPE-950-24%was about7.67×10-5S/cm, and The temperaturedependence on ionic conductivity of SPEs obeyed VTF rule. its electrochemical stabilitywindows was around4.3V. This indicate that SPE-950have an excellent electrochemicalproperties. TG analysis indicated that the initial decomposition temperature of SPEs wasaround240℃, which showed SPEs having excellent thermal stability.