Recently, iChEM researcher Huaming Zhang and Xianfeng Li from Division of Energy Storage, DICP, made new progress in porous membranes for flow battery application. Related results were published in Angew. Chem. Int. Ed. (Angew. Chem. Int. Ed. 55, 2016, 3058-3062).

The research team overcame the constraints of traditional ion exchange mechanism and put forward an innovative concept of ion-selective transportation (Energy Environ. Sci. 2011, 4, 1676), they applied zeolite-coated membranes into flow batteries for the first time. Based on these results, they further did lots of work concerning zeolite-coated membranes (Energy & Environmental Science, 2016, 9, 441-447，Energy & Environmental Science 2013, 6, 776; Energy & Environmental Science 2012,5, 6299; Energy & Environmental Science 2011,4, 1147; Adv. Funct. Mater., 2015, 25, 2583; Adv. Funct. Mater. 2016，26，210-218).

Among the researchers of porous membranes for flow batteries, the most challenging problem is the mechanism of ion exchange. The pores of currently explored membranes are usually asymmetric with high resistance, therefore hard to testify ion-selective transportation mechanism. Fabricating ion exchange membranes with pore size between Stokes radii of protons (<0 .24nm) and hydrated multivalent vanadium ions (>0.6 nm) is critical. ZSM-35 was deliberately selected as a zeolite scaffold owing to its appropriate pore size (0.42 nm×0.54 nm for 10-ring apertures and 0.35 nm×0.48 nm for 8-ring apertures), which is in the range between the Stokes radii of protons (0.24 nm) and hydrated multivalent vanadium ions (>0.6 nm). The research team successfully applied ZSM-35 into porous membranes. This membrane is able to maintain an EE of 81.34 % even at a high current density of 200 mA cm−2. Such exceptional results have never been reported.

The research was funded by the China Natural Science Foundation and the Outstanding Young Scientist Foundation, Chinese Academy of Sciences (CAS), Science and Technology Service Network Initiative and Dalian Municipal Outstanding Young Talent Foundation.

paper link：http://onlinelibrary.wiley.com/doi/10.1002/anie.201510849/full