Nav: Home

Scientists make breakthrough in ion-conducting composite membranes

January 07, 2020

Chinese researchers under the direction of Profs. LI Xianfeng and ZHANG Huamin from the Dalian Institute of Chemical Physics (DICP) of the Chinese Academy of Sciences recently developed an ultrathin ion-conducting membrane with high selectivity and conductivity that can boost the power of flow batteries. The study was published in Nature Communications.

Membranes are key components of flow batteries. They separate reactive materials in the negative and positive chambers while permitting the transfer of ions across the membrane at the same time. The efficiency of flow batteries greatly depends on the ion selectivity and conductivity of these membranes.

Based on their previous study (Environ.Sci., 2011, 4, 1676), LI's group found that the key challenge for ion-conducting membranes is the "trade-off" between ion selectivity and conductivity. Porous membranes using the traditional phase inversion method of construction had tortuous and poorly connected pores, resulting in low ion conductivity.

In contrast, composite membranes possess separately tuned selective layers supported on substrates. "A composite membrane with a very thin selective layer and a highly conductive substrate hopefully overcomes the trade-off between ion selectivity and conductivity and further improves flow battery performance," said Prof. LI.

To this end, the researchers utilized interfacial polymerization to fabricate a thin-film composite membrane. This membrane has an ultra-thin cross-linked polyamide selective layer and a highly conductive support layer. The ultrathin selective layer is only 180 nm thick. It offers a very short ion-transfer pathway and has very low area resistance.

The cross-linked polyamide has free volume between the size of hydronium and hydrated vanadium ions. Vanadium ions, due to their size, are highly resistant to crossover, thus endowing the membrane with high ion selectivity.

Flow batteries with a thin-film composite membrane could work at higher current density. This would allow the use of a smaller battery stack to generate higher power and reduction in the cost of battery stacks.

The proton transfer mechanism in polyamide selective layers can be further understood by utilizing the Grotthuss mechanism to make theoretical calculations of proton transfers along water chains and carboxyl groups. Results provide new ideas for designing advanced ion-selective membranes that can also be applied to flow batteries.

Chinese Academy of Sciences Headquarters

Related Conductivity Articles:

Making plastic more transparent while also adding electrical conductivity
In an effort to improve large touchscreens, LED light panels and window-mounted infrared solar cells, researchers at the University of Michigan have made plastic conductive while also making it more transparent.
New high proton conductors with inherently oxygen deficient layers open sustainable future
Scientists at Tokyo Institute of Technology (Tokyo Tech) and the Australian Nuclear Science and Technology Organisation (ANSTO), discover a new family of high proton-conducting materials -- 'the hexagonal perovskite-related oxides' -- and shed light on the underlying mechanisms responsible for their conductivity.
Extremely low thermal conductivity in 1D soft chain structure BiSeX (X = Br, I)
Researchers found a new sort of simple one-dimensional (1D) crystal structured bismuth selenohalides (BiSeX, X = Br, I) with extremely low thermal conductivity.
Minimizing thermal conductivity of crystalline material with optimal nanostructure
Japanese researchers successfully minimized thermal conductivity by designing, fabricating, and evaluating the optimal nanostructure-multilayer materials through materials informatics (MI), which combines machine learning and molecular simulation.
Skoltech researchers use machine learning to aid oil production
Skoltech scientists and their industry colleagues have found a way to use machine learning to accurately predict rock thermal conductivity, a crucial parameter for enhanced oil recovery.
Scientists measured electrical conductivity of pure interfacial water
Skoltech scientists in collaboration with researchers from the University of Stuttgart, the Karlsruhe Institute of Technology and the Russian Quantum Center achieved the first systematic experimental measurements of the electrical conductivity of pure interfacial water, hence producing new results significantly extending our knowledge of interfacial water.
User research at BESSY II: How new materials increase the efficiency of direct ethanol fuel cells
A group from Brazil and an HZB team have investigated a novel composite membrane for ethanol fuel cells.
Atomic magnetometer points to better picture of heart conductivity
Mapping the electrical conductivity of the heart would be a valuable tool in diagnosis and disease management, but doing so would require invasive procedures, which aren't capable of directly mapping dielectric properties.
Quantum mechanical simulations of Earth's lower mantle minerals
The theoretical mineral physics group of Ehime University led by Dr.
Heat transport property at the lowermost part of the Earth's mantle
Lattice thermal conductivities of MgSiO3 bridgmanite and postperovskite (PPv) phases under the Earth's deepest mantle conditions were determined by quantum mechanical computer simulations.
More Conductivity News and Conductivity Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Debbie Millman: Designing Our Lives
From prehistoric cave art to today's social media feeds, to design is to be human. This hour, designer Debbie Millman guides us through a world made and remade–and helps us design our own paths.
Now Playing: Science for the People

#574 State of the Heart
This week we focus on heart disease, heart failure, what blood pressure is and why it's bad when it's high. Host Rachelle Saunders talks with physician, clinical researcher, and writer Haider Warraich about his book "State of the Heart: Exploring the History, Science, and Future of Cardiac Disease" and the ails of our hearts.
Now Playing: Radiolab

Insomnia Line
Coronasomnia is a not-so-surprising side-effect of the global pandemic. More and more of us are having trouble falling asleep. We wanted to find a way to get inside that nighttime world, to see why people are awake and what they are thinking about. So what'd Radiolab decide to do?  Open up the phone lines and talk to you. We created an insomnia hotline and on this week's experimental episode, we stayed up all night, taking hundreds of calls, spilling secrets, and at long last, watching the sunrise peek through.   This episode was produced by Lulu Miller with Rachael Cusick, Tracie Hunte, Tobin Low, Sarah Qari, Molly Webster, Pat Walters, Shima Oliaee, and Jonny Moens. Want more Radiolab in your life? Sign up for our newsletter! We share our latest favorites: articles, tv shows, funny Youtube videos, chocolate chip cookie recipes, and more. Support Radiolab by becoming a member today at