Low permeable composite membrane based on sulfonated poly(phenylene oxide) (sPPO) and silica for vanadium redox flow battery

Suc

ACS Sustainable Chem. Eng.

et al. 2019

Four sulfonated poly(p-phenylene)-based ionomer materials with different hydrophobic block structures are synthesized in order to investigate the effect of the hydrophobic block structure on the durability of ionomer membrane in vanadium redox flow batteries (VRFBs). The structural differences of the hydrophobic blocks scarcely affect the physical, electrochemical, and morphological properties of the block copolymer-type ionomers. On the contrary, according to an ex situ soaking test and an in situ VRFBs cell test, the structural differences of the hydrophobic block greatly affect the chemical stability of the ionomer membranes. Among the four ionomers, the sPP-b-PSK membrane shows outstanding cell performance (Coulombic efficiency of 99.3% and energy efficiency of 72.6%) as well as excellent chemical stability even after long-term operation of 2 000 cycles. These results are conceptually helpful for designing chemically stable ionomers.

Section: Introductionmentioning

confidence: 99%

Structural Effect of the Hydrophobic Block on the Chemical Stability of Ion-Conducting Multiblock Copolymers for Flow Battery

Suc

ACS Sustainable Chem. Eng.

et al. 2019

“…Recently, the introduction of inorganic additives in hydrocarbon polymer‐based organic‐inorganic hybrid composite membranes has been developed as a cost effective membrane and considered as an alternative for the commercialized Nafion membranes . Apart from the numerous advantages in hydrocarbon polymer membranes, degradation is a serious issue during long‐term operation, which results in poorer chemical stability .…”

Section: Introductionmentioning

confidence: 99%

“…Recently, the introduction of inorganic additives in hydrocarbon polymer-based organic-inorganic hybrid composite membranes has been developed as a cost effective membrane and considered as an alternative for the commercialized Nafion membranes. 12,13 Apart from the numerous advantages in hydrocarbon polymer membranes, degradation is a serious issue during long-term operation, which results in poorer chemical stability. [14][15][16][17] On the other hand, further developments on fluoro-based composite membranes are still underway for achieving high performance due to good proton transportation and high chemical stability.…”

Section: Introductionmentioning

confidence: 99%

Development of perfluorosulfonic acid polymer‐based hybrid composite membrane with alkoxysilane functionalized polymer for vanadium redox flow battery

et al. 2019

Self Cite

Summary A new kind of alkoxy silane functionalized polymer (ASFP) is synthesized by selectively functionalized carboxyl groups as a novel inorganic precursor polymer to prepare organic‐inorganic hybrid membrane for vanadium redox flow battery (VRFB) system. The novel hybrid membrane has been fabricated by interconnection between hydrophilic domains of Nafion and ASFP functional group. The effective concentration of ASFP for hybrid membrane is 25% (wt/wt). The proton conductivity and selectivity of the hybrid membrane are comparable with those of the Nafion212 membrane, which is mainly attributed by the presence of additional hydrophilic domains in the hybrid membrane. The proton conductivity and ion exchange capacity of the Nafion‐ASFP (75:25) membrane is 0.061 S/cm and 0.68 meq/g, respectively. Remarkably, the Nafion‐ASFP membrane shows a low vanadium permeability (1.259 × 10−7 cm2/min) and high selectivity, which is an excellent advantage. As a result, the hybrid membrane shows comparable efficiency performance with Nafion212 over 50 cycles. Notably, the VRFB unit cell with Nafion‐ASFP membrane achieves higher coulombic efficiency than Nafion212. The hybrid membrane reveals a new route to develop an alternative fluorinated polymer membrane with numerous advantages especially cost‐effectiveness, homogeneous dispersion of inorganic silica precursor materials in the hybrid membrane without deterioration of mechanical strength, and lower vanadium ion crossover for VRFB system.

ACS Sustainable Chem. Eng.

“…The AGM separator can produce heat in reduction reactions during constant-voltage overcharge . The generated heat can cause an undesirable temperature rise or thermal runaway in LAB cells. ,− In addition, this condition is perhaps caused by the separator structure, acid stratification, and electrolyte drainage in the separator. ,, In recent years, numerous efforts have been dedicated in the energy storage area to enhance the performance and lower the manufacturing cost of separator/membranes. − Among the various efforts, a new approach of eco-friendly and cost-effective biocellulose (BC) membrane-based separators has gained significant consideration for many energy storage devices where membranes are used as separators to improve ion transportation. − Cellulose membranes possess more advantages such as low cost, outstanding hydrophilicity (more wettability), high water holding capacity, improved thermal and chemical stability, and excellent mechanical stability, , and they can meet the requirements of a separator for LAB. Furthermore, cellulose is renewable, abundant (from plants, bacteria, and other organisms), biodegradable, and biocompatible .…”

Section: Introductionmentioning

confidence: 99%

“…The weight of the hydrated sample was measured. The WU properties of the samples were calculated as follows 21 = − × W W W water uptake (%) 100 wet dry dry (4) where W wet is the weight of the completely hydrated membrane and W dry is the weight of the completely dehydrated membrane.…”

Section: ■ Introductionmentioning

confidence: 99%

Techno-Economical Feasibility of Biocellulose Membrane along with Polyethylene Film as a Separator for Lead-Acid Batteries

Roh

Palanisamy

Thangarasu

et al. 2019

Self Cite

In this present investigation, we applied an eco-friendly bacterial cellulose (BC) membrane along with a polyethylene (PE) separator as a separator for lead-acid battery systems. The key factor of the research is to lower the cost of the lead-acid battery by introducing the BC membrane along with a thin PE separator. The specific surface areas of the BC membrane and the PE separator were 46.72 and 35.89 m2 g–1, respectively, with high porosity, which can enhance the electrolyte uptake and movement. The identified pore sizes of the BC membrane and the PE separator are 13.67 and 56.18 nm, respectively. The closely arranged microfibrils in the BC membrane with the smaller pore size can uptake a high amount of electrolyte, and it can hold it for a long period with the hydrogen interactions. In addition, the BC membrane and the PE separator exhibited higher thermal stabilities. The water uptake property of the BC membrane is 130% at 30 °C, which results in considerable electrolyte uptake. The ion exchange capacity of AGM, PE separator, and BC membrane are ∼0.0, ∼ 0.0, and 0.127 meq/g, respectively. The higher IEC is attributed to the presence of hydrophilic functional groups in the BC membrane, which increase the ion transportation in the membrane. The ion conductivity of the BC membrane is considerably higher than those of the AGM and PE separator. The charge and discharge performances of the AGM and BC-PE battery systems were analyzed using lead-acid battery cells. The exhibited discharge performances of both battery systems were considerably similar at 0.1 and 0.2 A discharge current. The final discharge capacities of the AGM battery and the BC-PE battery were 0.96 and 0.94 Ah, respectively, at 0.1 A under identical conditions. A considerable cyclic stability was observed in the BC-PE battery system during long-term operation. From our experimental analysis results, a cost-effective hybrid combination of a BC membrane along with a PE separator can be considered as an efficient separator for lead-acid battery systems.