Preparation Of PAALi And PEO Based Solid Polymer Electrolytes Using Composite-in-situ Method

In these decades, solid polymer electrolytes (SPEs) have attracted more and more attention because of their widely potential applications, such as high-energy density batteries, electrochromic devices, photoelectrochemical cells and sensors. The situation of the research and recent developments for the SPEs were reviewed in this paper. Aimed at the key and difficult problem in the SPEs---how to increase the conductivity of SPE, the thesis was focused on the design of novel system and introduce of new preparation methods for the SPEs in order to give some theory directions for the improvements of SPEs. The ionic conductivity, mechanical and electrochemical stability of SPE has been known to be greatly enhanced by filling with inorganic particles. The various inorganic additives have been introduced into SPEs to obtain so called composite solid polymer electrolyte (CSPE). Because of the property failure of CSPE prepared by common methods such as mechanical blending due to the non-uniform distribution and the aggregation of inorganic particles in the polymer matrix, an novel preparation method, composite-in-situ, was introduced into the preparation of CSPE. The method "composite-in-situ" here means that the inorganic particles are produced in situ by the sol-gel process of precursors in the polymer medium, called as Sol-gel composite-in-situ, or formation of inorganic particles and polymerization of monomers carry out simultaneously, called as composite-in-situ polymerization. The composite-in-situ preparation and conducive property of poly(ethylene oxide) (PEO)-based and Poly(lithium acrylate) (PAALi)-based CSPEs were systematically studied. The main results gotten from our research are reviewed as below.(1) Three kinds of PEO-based CSPE PEO/LiClO₄/TiO₂, PEO/LiClO₄/SiO₂ and PEO/LiClO₄/KH560-SiO₂ were prepared by using the method of Sol-gel composite-in-situ. Alternating current impedance (AC) results showed that the temperature dependences of conductivity of PEO/LiClO₄/SiO₂, PEO/LiClO₄/KH560-SiO₂ and PEO/LiClO₄/TiO₂ composite polymer electrolytes are accordant to Arrhenius equation. The maximum of conductivities of PEO/LiClO₄/SiO₂ and PEO/LiClO₄/KH560-SiO₂ composite polymer electrolytes are 1.5×10⁵ S·cm^-1 and 4.8×10⁵ S·cm^-1 respectively found at 10wt% SiO₂ content. The maximum of conductivity of PEO/LiClO₄/TiO₂ composite polymer electrolytes is 5.5×10⁵ S·cm^-1 observed with 5% TiO₂ content. The conductivities of CSPE are obviously increased by addition of TiO₂ and SiO₂ at room temperature, which can be...