Redox flow batteries (RFBs) are the most preferred technology for primary grid-scale storage systems, as their power and energy can be decoupled. Unlike conventional batteries, RFBs can store energy for a longer duration, and it can respond fast in the event of destabilization of grid.1 Redox-active materials are key components in the RFB system because their physicochemical and electrochemical properties directly determine their battery performance and energy storage cost.2 In contrast to inorganic redox-active material, redox-active organic molecules are more promising candidate in the application of RFBs, due to their low cost, vast abundance, and high tunability of both potential and solubility.3 This research colloquium seminar will focus on the molecular engineering strategy to develop new organic redox active molecules for non-aqueous (NAORFB) and aqueous (AORFB) organic redox flow batteries. A NAORFB based on benzyl viologen (anode material) and N-hexyl phenothiazine (cathode material) derivative was tested in an inert condition without a glove box to investigate the stability of redox-active species.4 The high molecular weight redox-active species as a dimer of viologen (DV) utilise as anode material to suppress the crossover of redox-active species through the porous membrane in NAORFB.5 It reduces the capacity fading and enhances the CE of NAORFB. Besides, the AORFB based on the viologen redox active material has been explored. A water soluble quaternary ammonium salt viologen derivative used as an anolyte which coupled with 4-Hydroxy TEMPO as a catholyte for AORFB applications in a neutral medium. The detailed investigations comprising all mechanistic approaches and experimental details will be discussed in the seminar.
References:
1. Alotto, P.; Guarnieri, M.; Moro, F. Renewable Sustainable Energy Rev. 2014, 29, 325– 335.
2. Wei, X.; Pan, W.; Duan, W.; Hollas, A.; Yang, Z.; Li, B.; Nie, Z.; Liu, J.; Reed, D.; Wang, W.; Sprenkle, V. ACS Energy Lett. 2017, 2, 2187−2204.
3. Ding, Y.; Zhang, C.; Zhang, L.; Zhou, Y.; Yu, G. Chem. Soc. Rev. 2018, 47, 69– 103.
4. Mohapatra, S.K.; Ramanujam, K.; Sankararaman, S. J. Energy Storage 2023, 72, 108739.
5. Mohapatra, S.K.; Ramanujam, K.; Sankararaman, S. APL Energy 2023, 1, 036103.