Study On The Preparation And Electrochemical Property Of Polymer Electrolyte For Lithium-air Battery

Lithium-air?also known as lithium-oxygen?batteries have attracted considerable global attention in recent years due to their extremely high energy density?11140 whk/g?.The electrolyte is a key element in lithium-air batteries and the traditional organic electrolyte has great safety risk due to leakage.On the contrary,the polymer electrolyte has the advantages of high safety,high stability and easy processing comparing with the organic liquid electrolytes.A series of polymer base electrolytes for lithium air battery were designed and prepared in this paper.The polyurethane polymer is applied to the lithium-air battery via solution casting method.Polyurethane/PET composite electrolyte?PGPE?and polyurethane/cellulose composite electrolyte?CGPE?with the use of TEMPO possessed exellent electrochemical performance.The ionic conductivity of PGPE was 2.4×10^-4 S/cm at room temperature and the discharge platform was 2.6 V and the charging voltage was 3.6 V after 15 cycles with the cut-off capacity of 500mAh/g.The ionic conductivity of CGPE was 3.5×10^-4 S/cm at room temperature and the discharge platform was 2.6 V and the charging voltage was 3.7 V after 50 cycles with the cut-off capacity of 500 mAh/g.Given the selective permeability on lithium ion of the Nafion membrane,a new idea was proposed.The Nafion membrane was coated on a layer of polymer for blocking TEMPO and Li.In this paper,self-made thickness controllable Nafion membrane,the poly?vinylidene fluoride-hexafluoropropylene?copolymer and the oxidation reduction electric?TEMPO?were used to prepare a kind of quasi solid polymer electrolyte?NSPE?.The ionic conductivity of NSPE was 4.3×10^-4 S/cm at room temperature and the discharge platform was 2.6 V and the charging voltage was 3.7 V after 50 cycles with the cut-off capacity of 500 mAh/g.