Thin skinned asymmetric polybenzimidazole membranes with readily tunable morphologies for high-performance vanadium flow batteries

Peng, Sangshan; Yan, Xiaoming; Wu, Xuemei; Zhang, Daishuang; Luo, Yongliang; Su, Lei; He, Gaohong

doi:10.1039/c6ra24801b

Cited by 54 publications

(31 citation statements)

References 71 publications

Supporting

Mentioning

Contrasting

Order By: Relevance

“…Using symmetric porous structures, PBI membranes from [ 193 ] and [ 195 ] enable energy efficiencies of 87% and 90%. The asymmetrically porous PBI membrane from [ 194 ] enables a comparatively high energy efficiency of 82% as well.…”

Section: Membrane Developments In Recent Yearsmentioning

confidence: 99%

Polymer Membranes for All-Vanadium Redox Flow Batteries: A Review

et al. 2021

View full text Add to dashboard Cite

Redox flow batteries such as the all-vanadium redox flow battery (VRFB) are a technical solution for storing fluctuating renewable energies on a large scale. The optimization of cells regarding performance, cycle stability as well as cost reduction are the main areas of research which aim to enable more environmentally friendly energy conversion, especially for stationary applications. As a critical component of the electrochemical cell, the membrane influences battery performance, cycle stability, initial investment and maintenance costs. This review provides an overview about flow-battery targeted membranes in the past years (1995–2020). More than 200 membrane samples are sorted into fluoro-carbons, hydro-carbons or N-heterocycles according to the basic polymer used. Furthermore, the common description in membrane technology regarding the membrane structure is applied, whereby the samples are categorized as dense homogeneous, dense heterogeneous, symmetrical or asymmetrically porous. Moreover, these properties as well as the efficiencies achieved from VRFB cycling tests are discussed, e.g., membrane samples of fluoro-carbons, hydro-carbons and N-heterocycles as a function of current density. Membrane properties taken into consideration include membrane thickness, ion-exchange capacity, water uptake and vanadium-ion diffusion. The data on cycle stability and costs of commercial membranes, as well as membrane developments, are compared. Overall, this investigation shows that dense anion-exchange membranes (AEM) and N-heterocycle-based membranes, especially poly(benzimidazole) (PBI) membranes, are suitable for VRFB requiring low self-discharge. Symmetric and asymmetric porous membranes, as well as cation-exchange membranes (CEM) enable VRFB operation at high current densities. Amphoteric ion-exchange membranes (AIEM) and dense heterogeneous CEM are the choice for operation mode with the highest energy efficiency.

show abstract

Section: Membrane Developments In Recent Yearsmentioning

confidence: 99%

Polymer Membranes for All-Vanadium Redox Flow Batteries: A Review

et al. 2021

View full text Add to dashboard Cite

show abstract

“…Even at a very high current density of 220 mA cm −2 , the EE can reach 80% which is the highest value ever reported for PBI membranes (Figure 6b,c). [16,[29][30][31][32][37][38][39][40][41][42][43] Benefiting from the very thin skin layer and highly porous support layer, all prepared membranes showed much better battery performance than that of a commercial Nafion115 (CE = 94.2% VE = 90.6% EE = 85.3%), confirming the very high ion conductivity and selectivity of prepared membrane.…”

Section: Resultsmentioning

confidence: 82%

“…It is indicative of the breakthrough of the trade-off between vanadium selectivity and proton conductivity, confirming the superiority of our membrane design. [16,[29][30][31][32][36][37][38][39][40][41][42] It is interesting to find that most of the dense PBI membranes possess low vanadium permeability but suffer from the high area resistance while most of the porous PBI membranes have low area resistance but is hard to have low vanadium permeability. Obviously, most other methods suffer from the trade-off issue.…”

Section: Resultsmentioning

confidence: 99%

“…[11][12][13] The separation performance is ultimately determined by membrane morphologies. [14][15][16][17][18] For a membrane, one of the most troublesome and common issues is the trade-off between the selectivity and flux. For VFBs, membranes play the role of separating vanadium ions, while transporting protons to complete the internal circuit.…”

Section: Doi: 101002/aenm202001382mentioning

confidence: 99%

See 1 more Smart Citation

Membranes with Well‐Defined Selective Layer Regulated by Controlled Solvent Diffusion for High Power Density Flow Battery

Shi

Dai

et al. 2020

Advanced Energy Materials

View full text Add to dashboard Cite

Membranes with precise control of selective layer are designed and prepared by adjusting diffusion of solvents. Combining experiments and theoretical calculations, the formation mechanism of ion conductive membranes prepared by a non‐solvent induced phase separation (NIPS) method is found to be related to internal diffusion flux of solvent to the non‐solvent bath and external diffusion flux of non‐solvent to the casting solution. By regulating the internal and external diffusion rates via a two‐step NIPS method, a series of polybenzimidazole (PBI) porous membranes with independently controlled thin selective skin layers and highly porous support layers are fabricated, which achieve a simultaneous improvement in ion selectivity and proton conductivity. A vanadium flow battery assembled with a PBI membrane demonstrates an energy efficiency of 80% at a current density of 220 mA cm−2, which is the highest value among the reported PBI membranes. This provides a simple and effective way to fabricate membranes with well‐defined morphologies.

show abstract

“…That research inspired investigation of nanoporous membranes in VRFBs instead of cation-exchange membranes. [128][129][130][131][132][133][134][135] Particularly, a number of studies examined poly(benzimidazole) (PBI) membranes [136][137][138][139][140] and even advocated the use of PBI membranes for all VRFBs. [141] Pristine PBI membranes are nonporous and have low ionic conductivities.…”

Section: Nf Membranes In Vrfbsmentioning

confidence: 99%

Ion separations with membranes

Tang

Bruening

2020

Journal of Polymer Science

View full text Add to dashboard Cite

Ion separations are important for resource recovery, water treatment, and energy production and storage. Techniques such as chemical precipitation, selective adsorption, and solvent extraction are effective, but membranes may separate ions continuously with less waste and lower energy costs. Separation of monovalent and multivalent ions with nanofiltration or electrodialysis membranes already enables water softening and edible salt purification. Similar membranes are attractive as separators in vanadium redox flow batteries. Selective partitioning of divalent counter-ions into ion-exchange membranes even allows transport of these ions against their concentration gradients in salt mixtures. However, separations of ions with the same charge is more challenging. Recent research demonstrated highly selective ion "sieving" at small scales. Separations using electrical potentials and differences in ion electrophoretic mobilities are promising, but relatively unexplored. Carrier-mediated transport affords high selectivity in liquid membranes, but these systems are not very stable, and selective transport via hopping between anchored carriers has proven elusive. Finally, this paper discusses how concentration polarization decreases selectivities in many membrane processes. Although development of selective, inexpensive ion-separation membranes is a work in progress, successes in water softening and edible salt purification suggests that future selective membranes will serve as complementary methods to traditional purification techniques.

show abstract

Thin skinned asymmetric polybenzimidazole membranes with readily tunable morphologies for high-performance vanadium flow batteries

Cited by 54 publications

References 71 publications

Polymer Membranes for All-Vanadium Redox Flow Batteries: A Review

Polymer Membranes for All-Vanadium Redox Flow Batteries: A Review

Membranes with Well‐Defined Selective Layer Regulated by Controlled Solvent Diffusion for High Power Density Flow Battery

Ion separations with membranes

Contact Info

Product

Resources

About