Nanocomposite anion-exchange membranes for redox flow batteries

Introduction: The ion-exchange membrane is a vital part of fuel cells, rechargeable batteries, and other electrochemical devices because it determines their efficiency (1). Anion exchange membranes are currently a hot topic of research because they are more efficient and cost-effective in practical applications (2). Organic–inorganic hybrid membranes found to be excellent materials for practical applications due to their improved electrochemical properties, mechanical strength, chemical and thermal stability.

Methods: Layered double hydroxides (LDHs) of Magnesium with Aluminium ([Mg-Al] LDH) were prepared by precipitation at low saturation. 5 wt% PVA solution was prepared. Then a calculated amount of double hydroxide was stirred with PVA solution for 8 hrs and crosslinked using glutaraldehyde. The membranes were characterized by XRD, AC impedance analysis and conducted charge –discharge experiment in redox-flow battery (3).

Results & Discussions: Figure 1 shows the XRD pattern of Mg-Al LDHs. The diffraction pattern of the sample is well correlated with the standard diffraction pattern (ICSD PDF# 54-1030). A Galvanostatic charge–discharge experiment was carried out in a redox-flow battery using the prepared membrane as a separator, as shown in (Figure 2). Over multiple cycles, the results showed above 70% efficiency. This indicates a low level of cross mixing of ions (4).

Conclusions: We used a co-precipitation method to make nanoparticles of ([Mg-Al] LDH. Its phase purity was revealed by the XRD pattern. The newly fabricated nanocomposite membrane was put to the test as a separator in a redox flow battery. The results of a Galvanostatic charge-discharge test revealed that coulombic efficiency was greater than 70 %.

Keywords: Ion-exchange membrane, Redox-flow battery, Charge–discharge experiment, Hybrid membranes

References

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2. Yang Q, Li L, Gao XL, Wu HY, Liu FH, Zhang QG, et al. Crown ether bridged anion exchange membranes with robust alkaline durability. J Memb Sci [Internet]. Elsevier B.V.; 2019;578(November 2018):230–8. Available from: https://doi.org/10.1016/j.memsci.2019.02.038

3. Suc M, Yeop H, Young H, Hyun S, Kim T, Oh S, et al. Crosslinked anion exchange membranes with primary diamine-based crosslinkers for vanadium redox fl ow battery application. J Power Sources [Internet]. Elsevier B.V; 2017;363:78–86. Available from: http://dx.doi.org/10.1016/j.jpowsour.2017.07.068

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