Preparation Of Cellulose-based Alkaline Polyelectrolyte Membrane And Its Application In Zinc-air Battery

Alkaline solid polymer electrolyte?ASPE?membrane as an alkaline solution replacement is one of the key components of batteries.It is obtained great development in recent years because of low pollution,no leakage,low corrosion and lightweight.Based on the conduction mechanism of the ASPE membranes,the cellulose was skillfully introduced into the matrix of PVA PEO and PAA.Several series ASPE membranes with outstanding performance were successfully prepared by structure design.The ionic conductivity,thermodynamic properties,mechanical properties and electrochemistry properties of ASPE membranes were characterized.The alkaline polymer electrolyte membranes showed favorable alkali resistance,high ionic conductivity,good mechanical properties and excellent electrochemical stability.The research has brought novel method for designing outstanding performance alkaline polymer electrolytes and provided valuableMain content as follows:?1?The PVA/PAA/MCC/KOH alkaline polymer electrolyte membranes were prepared by solution polymerization and casting method.MBA was acted as a crosslinker to crosslink the PAA and enhance the mechanical properties of ASPE.SEM showed that the MCC was dispersed in the matrix heterogeneously.XRD and TG explained that the degree of crystallinity of ASPE was reduced and the moisture content of ASPE was increased due to the MCC,respectively.In order to mearsed the electrochemical properties of ASPE,the electrochemical workstation was used.The results proved that the ionic conductivity and electrochemical stability window of ASPE were improved with the addition of MCC.The ionic conductivity was about0.095 Scm^-1and the electrochemical stability window was about 1.8 V.And the mechanical properties were improved obviously.Because of the elongation at break was from 133%to 203%.?2?The PVA/PEO/LD-MCC/KOH alkaline polymer electrolyte membranes were prepared by solution blending and casting method.The LD-MCC was prepared by MCC which dealt with by LiCl/DMAc solution.The structure morphology was meatured by SEM and EDX.The results showed that the LD-MCC was distributed in the PVA/PEO matrix and kept a favorable compatibility with the matrix.The content of KOH for LD-MCC surface was more than the matrix by reason of the interaction with hydroxyl and KOH.The consequence of TG demonstrated that the LD-MCC was contributed to increase the water retentivity of ASPE.The electrochemical testing declared that PVA/PEO/LD-MCC5/KOH?7g?alkaline polymer electrolytes possessed greatest ionic conductivity about 0.153 Scm^-1and the widest electrochemical stability window about 1.8 V.It was also known that the physical properties of ASPES were reinforced by LD-MCC duo to hydrogen bonds.The Zn-air batteries could discharge to last for 560 min.?3?The RDC membranes were prepared by the degrease cotton which dissolved by LiOH/urea aqueous solution.The RDC membranes were coated by cross-linked PAAK to acquire the RDC/PAAK membranes and soak the various concentrations solution of KOH to prepare the RDC/PAAK/KOH alkaline polymer electrolytes.The surface morphology of ASPE was measured by SEM and the result was that APSE had a sandwich structure and continuous phase with KOH.XRD explained that the the degree of crystallinity of ASPE was reduced because of the PAAK could break the aggregation of RDC films and enhance the mechanical properties of ASPE dramatically.The electrical Performance was tested by the electrochemical workstation.The consequence prove that the ionic conductivity and the electrochemical stability window of RDC/PAAK/KOH?8M?-3h alkaline polymer electrolytes were 0.25 Scm^-1and 2.0 V,respectively.The Zn-air batteries with ASPES had a higher capacity density and energy density about 225 mAh/g and 175 mWh/g,respectively.The dicharding time was about 550 min.