| With the market demand for high-energy,high-density batteries,commercial lithium-ion batteries can no longer meet the requirements.Lithium-air batteries have the highest theoretical energy density among many rechargeable lithium secondary batteries(3500 Wh kg-1),which shows a very considerable application prospects.However,lithium-air batteries based on traditional liquid electrolytes face many problems in terms of safety,coulomb efficiency,and long cycle life.The use of polymer electrolytes in lithium-air batteries can effectively improve the problems caused by traditional liquid electrolytes.In this paper,the QS-NP quasi-solid polymer electrolyte system is designed through a reasonable experimental scheme and its electrochemical performance and the effect of the polymer electrolyte on the electrochemical performance of lithium-air batteries are explored.The perfluorosulfonic acid membrane with a thickness of 15?m-30?m prepared by the solution casting method in this system ensures the mechanical strength of the system,and can effectively resist the attack of the strong oxidizing substance lithium peroxide produced by the positive electrode and prevent anions and some large molecules migrate.The polyvinylidene fluoride-hexafluoropropylene film modified by liquid electrolyte shows good compatibility with metal lithium anodes.QS-NP quasi-solid polymer electrolyte did not decompose significantly at 200?,indicating that it has excellent thermal stability.In addition,the QS-NP quasi-solid polymer electrolyte exhibits a high lithium ion migration number of 5.1 and a wide electrochemical window of 5.1V under the environmental conditions of 25±2?.Lithium-oxygen batteries based on QS-NP quasi-solid polymer electrolysis exhibitrelatively excellent cycle stability at 25±2°C and can effectively circulate 56 cycles.QS-NP quasi-solid polymer electrolyte system provides an effective choice for improving the performance of lithium-oxygen batteries. |
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