Preparation And Application Of PVA-based Polymer Electrolyte

Polymer electrolyte involves electrochemistry, organic chemistry, inorganic chemistry, polymer chemistry as a new subject, which has potential application in its Ni/Cd battery, Ni/Zn batteries, Ni/MH battery, metal air battery, the alkaline fuel cell, protons membrane fuel electricity and super capacitors. In this study, PVA/MLS/KOH/H2O and PVA/imidazole/EC proton conducting membrane are prepared and are studied by XRD, SEM, TG, AC and CV. The results are showed as follow:(1) A novel organic-inorganic alkaline solid electrolytes based PVA/MLS/KOH/H2O was prepared by a solution casting method, conductivity of alkaline solid electrolyte PVA-MLS-KOH-H2O is related to and lithium magnesium silicate content, microstructure, alkali absorption rate and so on. The addition of lithium magnesium silicate, the electrical conductivity of the alkaline solid polymer electrolyte was obviously improved, It was observed that the highest4.65×10-2S/cm. The temperature dependence of proton conductivity of the polymer electrolytes obeys Arrhenius law.(2)The discharge voltage plateau of1.15V and1.25V at1C and0.5C was observed for the Ni/MH cell with the PVA/MLS/KOH/H2O composite membrane. After350circles at1C, the charge-discharge efficiency is85%, compared with Ni/MH cell with6mol/L KOH, the cycle performance of Ni/MH cell with the PVA/MLS/KOH/H2O was improved; The discharge voltage plateau of1.6V,1.55V,1.40V at0.5C,1C and2C was observed for the Ni/Zn cell with the PVA/MLS/KOH/H2Ocomposite membrane. Compared with Ni/Zn cell with liquid electrolyte, the cycle performance of Ni/Zn cell with the PVA/MLS/KOH/H2O was improved due to Polymer electrolyte weaking the corrosion of Zn electrode.(3) A new anhydrous and transparent proton conducting membrane based on poly (vinylalco-hol)(PVA), imidazole (Imi), and Ethylene Carbonate (EC) was prepared by solution casting method, which proton transport number between0.857and0.968. The structure of PVA/Imi/EC composite membrane was studied by X-ray diffraction, TG and FTIR. The PVA/Imi/EC composite membrane still keep the good thermal stability in200℃, the highest electrical conductivity of the electrolytes at30℃reached8.42×10-5S/cm. The temperature dependence of proton conductivity of the polymer electrolytes obeys Arrhenius law, The XRD and FTIR research shows that:PVA hydrogen bond was destroyed and the interactions between the PVA molecular chain was recede due to imidazole join in, so that the amorphous nature of PVA increased and the proton conductivity of the polymer electrolytes was improved. The super capacitor with PVA/imidazole/EC show a good capacitance performance.