The Study Of Novel Polymer Based Composite Electrolyte For Solid State Lithium Air Battery

With the exhaustion of oil,natural gas,and coal,it is essential to develop the new-energy automobile industry for reducing the pressure on energy and the environment.Recently,the lithium-air battery exhibited important application prospect in the field of new generation of electric cars due to it great theoretical energy density?11140 Wh kg-1?.It has many advantages like high theoretical or practical energy density than the traditional batteries such as sealed,Nickel–cadmium battery and lithium ion battery.Therefore,it was considered to be the best choice for application of the electric car in the future.Nevertheless,the organic liquid electrolytes exists some shortcomings like weeping,inflammability,lower capacity and byproducts,which impedes the development of Li-O₂ battery.Up to date,polymer electrolyte was received greet attention due to its higher safety,stability and flexibility.In this paper,polymer based quasi solid electrolyte was designed and fabricated,which was applied to Li-O₂ battery.The main research content is as follows:?1?Polyurethane/cellulose composite electrolyte?CGPE?was fabricated via solution casting method.This study demonstrated that the CGPE possessed preeminent comprehensive properties such as sufficient room-temperature ionic conductivity(4.8 ×10-4 S cm^-1),high lithium ion transport number?t+=0.68?and improved electrochemical stability?4.4 V vs Li+/Li?.Moreover,the assembled LiFePO4/Li battery using CGPE exhibited outstanding rate capacity and remarkable cycle performance.Further,the Li-O₂ battery using CGPE showed lower charge overpotential and excellent cycling stability.?2?A high performance sandwich-structured quasi-solid polymer electrolyte?QSPE?is designed to meet the requirement of both cathode and anode.which was composed of lithiated Nafion ionomer?Li-Nafion?,Polymethymethacrylate?PMMA?,and Polypropylene carbonate?PPC?.It is demonstrated that the QSPE exhibits excellent permselectivity to block redox mediator shuttling,as well as good ionic conductivity and high electrochemical window.A solution mechanism formation of discharge product was demonstrate in the Li-O₂ cell with QSPE and the redox mediator works well for cycles at room temperature.Our sandwich-structured design strategy would provide a new pathway to promote the properties of Li-O₂ battery.