PVDF-PFSA Polymer Ion Conductor For Solid-state Lithium-ion Battery And Fuel Cell

With the continuous development of polymer materials,polymer ion conductors,as an important branch of polymer materials,have a wide range of applications in battery energy materials.This article mainly introduces the application of polymer ion conductors in solid-state lithium-metal batteries for energy storage devices and proton exchange membrane fuel cells for energy conversion devices.Traditional solid-state lithium-metal batteries have low ion conductivity at room temperature,poor battery performance,and traditional pure sulfonic acid resin proton exchange membranes with high swelling rate,poor mechanical strength,and unstable battery performance.Studying polymer ion conductors is a hot direction currently to solve these mentioned problems.In this article,we mainly study polyvinylidene fluoride(PVDF)/perfluorosulfonic acid(PFSA)polymer ion conductors to improve the deficiencies of traditional polymer solid electrolytes and proton exchange membranes.The research content includes the following aspects:First,it briefly introduces the working principle,classification and development of solid-state lithium-metal batteries,and summarizes the development of polymer ion conductors in polymer solid electrolytes,and then introduces traditional sulfonic acid resin proton exchange membranes and the lack of commercial proton exchange membranes.The research direction of this paper is proposed as solid electrolyte membrane and proton exchange membrane based on polyvinylidene fluoride/perfluorosulfonic acid polymer ion conductor material.Second,the study of solid electrolyte separators with different ratios of PVDF-PFSA,obtained 40%PFSA composite polymer solid electrolyte at room temperature with a lithium ion conductivity of 0.83 × 10-3 S/cm,assembled lithium iron phosphate solid state battery after cycling for 1000 cycles at 0.5 C room temperature,the battery capacity remained at 89 mAh/g,and the lithium ion transference number reached 0.524.The 40%PFSA composite polymer solid electrolyte has good stability and electrochemical performance.Third,the composite proton exchange membrane with different ratios of PVDF-PFSA was studied.By contrast with the traditional pure sulfonic acid resin proton exchange membrane,the composite membrane had increased mechanical strength and decreased swelling rate as the content of PVDF increases.When the ratio of PVDF to PFSA was 2:3,the swelling rate could reach 3.06%,and the mechanical strength could reach 14.9 MPa.The preparation process of the composite membrane was simple,the raw materials were all domestically produced materials,and the maximum power density reached 716 mW/cm2.In this paper,by studying the PVDF composite PFSA ion conductor,it has improved the low ion conductivity of the traditional polymer solid-state battery at room temperature,and enhanced the mechanical performance and stability of the traditional PFSA proton exchange membrane,and reduced the production cost of the proton exchange membrane.Studying the PVDF composite PFSA ion conductor has certain reference value for promoting the development of polymer solid-state lithium-ion batteries and proton exchange membrane fuel cells.