非氟离子交换膜在全钒液流电池中的应用及氧化稳定性研究进展OA

In vanadium flow batteries(VFBs),membranes serve the functions of preventing the cross-mixing of vanadium ions and facilitating proton transport.The performance and stability of membranes directly determine the performance and stability of the battery system.Currently,the most widely used perfluorosulfonic acid membranes suffer from high costs,poor ion selectivity,and heavy reliance on imports,partially hindering the industrialization of VFBs.Compared with perfluorosulfonic acid membranes,non-fluorinated ion exchange membranes own broader materials selection.Polybenzimidazole(PBI),sulfonated polyetheretherketone(SPEEK),sulfonated polyimide(SPI),and polyvinylidene fluoride(PVDF)can be used to fabricate ion exchange membranes of VFBs.Generally,non-fluorinated ion exchange membranes offer advantages of high selectivity and low cost.Nevertheless,their oxidative stability fails to meet practical application requirements in the highly acidic and strongly oxidizing environments of VFBs.This paper reviews the Research Progress and application prospects of different non-fluorinated ion exchange membranes in VFBs.It introduces the characteristics of offline and online testing methods for evaluating the oxidative stability of non-fluorinated ion exchange membranes.Finally,the paper summarizes the research progress on the oxidative stability of several non-fluorinated ion exchange membranes and analyzes their degradation mechanisms.By comparing the degradation products obtained from offline and online tests,it is confirmed that the offline testing method can also truly reflect the oxidation process of non-fluorinated ion exchange membranes during battery operation.This paper concludes the application status and degradation rules of some non-fluorinated ion exchange membranes in VFBs,providing significant guidance for the design and development of high-stability membranes.