• KEPCO Journal on Electric Power and Energy
• /
• v.2 no.1
• /
• pp.127-131
• /
• 2016

Polymer electrolyte membrane for unitized regenerative fuel cells requires high proton conductivity, high dimensional stability, low permeability, and low cost. However, DuPont's Nafion which is a commercial polymer electrolyte membrane has high permeability, high cost, and decreasing proton conductivity and dimensional stability over $80^{\circ}C$. To address these problems, sulfonated poly ether ether ketone (sPEEK) which is a low cost hydrocarbon polymer is selected as matrix polymer for the preparation of polymer electrolyte membrane. In addition, composite membrane with improved proton conductivity and dimensional stability is prepared by introducing sulfonated graphene oxide (sGO). The fundamental properties of polymer electrolyte membranes are analyzed by investigating membrane's water content, dimensional stability, proton conductivity, and morphology. The cell test is conducted to consider the possibility of application of sPEEK/sGO composite membrane for an unitized regenerative fuel cell.

• Applied Chemistry for Engineering
• /
• v.30 no.1
• /
• pp.1-10
• /
• 2019

Composite polymer electrolyte membranes based on porous supports have been recognized as an alternative for fuel cell applications since it can provide both mechanical as well as electrochemical stabilities. This mini-review highlights recent advances in supported composite polymer electrolyte membranes using porous matrix and nanofibrous supports. In addition, a comprehensive table listing a wide range of anion and proton exchange pore filling membranes was provided at the end of the review.

• Journal of Electrochemical Science and Technology
• /
• v.13 no.3
• /
• pp.362-368
• /
• 2022

The application of polymer composite electrolyte in all-solid-state lithium-sulfur battery (ASSLSBs) can guarantee high energy density and improve the interface contact between electrolyte and electrode, which has a broader application prospect. However, the inherent insulation of the sulfur-cathode leads to a low electron/ion transfer rate. Carbon materials with high electronic conductivity and electrolyte materials with high ionic conductivity are usually selected to improve the electron/ion conduction of the composite cathode. In this work, PEO-LiTFSI-LLZO composite polymer electrolyte (CPE) with high ionic conductivity was prepared. The ionic conductivity was 1.16×10^-4 and 7.26×10^-4 S cm^-1 at 20 and 60℃, respectively. Meanwhile, the composite sulfur cathode was prepared with Sulfur, reduced graphene oxide and composite polymer electrolyte slurry (S-rGO-CPEs). In addition to improving the ion conductivity in the cathode, CPEs also replaces the role of binder. The influence of different contents of CPEs in the cathode material on the performance of the constructed battery was investigated. The results show that the electrochemical performance of the all-solid-state lithium-sulfur battery is the best when the content of the composite electrolyte in the cathode is 40%. Under the condition of 0.2C and 45℃, the charging and discharging capacity of the first cycle is 923 mAh g^-1, and the retention capacity is 653 mAh g^-1 after 50 cycles.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2003.05c
• /
• pp.88-90
• /
• 2003

The purpose of this study is to research and develop tin oxide-flash composite for lithium Ion polymer battery. Tin oxide is one of the promising material as a electrode active material for lithium Ion polymer battery (LIPB). Tin-based oxides have theoretical volumetric and gravimetric capacities that are four and two times that of carbon, respectively. We investigated cyclic voltammetry and charge/discharge cycling of SnO-flyash/SPE/Li cells. The first discharge capacity of SnO-flyash composite anode was 720 mAh/g. The discharge capacity of SnO-flyash composite anode 412 and 314 mAh/g at cycle 2 and 10 at room temperature, respectively. The SnO-flyash composite anode with PVDF-PMMA-PC-EC-$LiClO_4$ electrolyte showed good capacity with cycling.

• Proceedings of the Korean Institute of Electrical and Electronic Material Engineers Conference
• /
• 2000.11a
• /
• pp.359-362
• /
• 2000

The purpose of this study is to research and develop graphene composite for lithium polymer battery. VO(graphene) composite is one of the promising material as a electrode active material for lithium polymer battery(LPB). We investigated AC impedance response and charge/discharge cycling of VO(graphene)/SPE/Li cells. The first discharge capacity of VO(graphene) cathode with 50wt.% V$_2$O$\sub$5/ was 150mAh/g, while that of VO(graphene) cathode with 85wt.% V$_2$O$\sub$5/ was 248mAh/g. The Ah efficiency was above 98% after the 2nd cycle. The discharge capacity of VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ was 718 and 266mAh/g at cycle 1 and 10 at room temperature, respectively. The VO(graphene) anode with 3wt.% V$_2$O$\sub$5/ in PVDF-PAN-PC-EC-LiC1O$_4$ electrolyte showed good capacity with cycling.

• Bulletin of the Korean Chemical Society
• /
• v.33 no.9
• /
• pp.2949-2954
• /
• 2012

Nano ZnO with an average size of 8 nm was prepared by thermal decomposition of zinc oxalate at $450^{\circ}C$. A series of based composite polymer electrolyte PEO-$LiClO_4$ and nano ZnO as a filler have been synthesized using solution cast technique, with varying the filler ratio systematically. XRD, DSC and FTIR studies have been conducted to investigate the structure and interaction of different groups in the composite polymer electrolyte. Effect of nano ZnO ceramic filler concentration on the structure of composites and their electrical properties (DC-conductivity, AC-conductivity, dielectric constant, dielectric loss and impedance) at different frequencies and temperatures was studied. Melting temperature ($T_m$) of PEO decreased with the addition of both $LiClO_4$ salt and nano ZnO filler due to increasing the amorphous state of polymer. All composite samples showed an ionic conductivity. The maximum room temperature ionic conductivity is found for $(ZnO)_{0.5}(PEO)_{12}(LiClO_4)$ composite sample. All the results are correlated and discussed.

• Transactions of the Korean hydrogen and new energy society
• /
• v.28 no.3
• /
• pp.246-251
• /
• 2017

To fabricate a hydrocarbon polymer electrolyte composite membrane incorporated with Pt nanoparticle, the polymer electrolyte membrane made of a sulfonated-fluorinated hydrophilic-hydrophobic block copolymer (SFBC) and sulfonated poly (ether ether ketone) (SPEEK) blend in the wight ratio of 1 : 1 was synthesized, and a simple drying process was used in order to incorporate Pt nanoparticle into the SFBC/SPEEK film by reducing platinum (II) bis (acetylacetonate), Pt $(acac)_2$. The distribution of the Pt nanoparticles was observed by transmission electron microscopy (TEM), and mechanical and thermal properties were tested by universal testing machine (UTM) and thermogravimetry analyzer (TGA). Cation conductivity, ion exchange capacity (IEC) and I-V characteristics were estimated.

• 한국신재생에너지학회:학술대회논문집
• /
• 2009.11a
• /
• pp.350-354
• /
• 2009

In this work, polymer - inorganic composites have prepared using polymer such as polyethylene glycol (PEG)/poly (methyl methacrylate, PMMA) and inorganic nanofillers materials such as TiO2 nanotubes (TiNTs)/carbon nanotubes (CNTs). The extensive structural, morphological and ionic properties revealed that the high surface area and tubular feature of nanofillers improved the interaction and cross-linking to polymer matrix which is significantly enhanced the ionic conductivity and electrical properties of composite electrolytes. Comparably high conversion efficiency ~4.5% has been observed by using the newly prepared PEG-TiNTs composite solid electrolyte as compared with PMMA-CNTs electrolyte based DSSCs (~3%). The detailed comparative properties would be discussed in term of their structural, morphology, ionic and photovoltaic properties.

• Bulletin of the Korean Chemical Society
• /
• v.32 no.2
• /
• pp.605-608
• /
• 2011

Hybrid composite membranes were prepared by coating poly(ethylene oxide) and $SiO_2$ particles onto the porous polypropylene nonwoven matrix. Gel polymer electrolytes prepared by soaking the hybrid composite membranes in an organic electrolyte solution exhibited ionic conductivities higher than $1.1{\times}10^{-3}Scm^{-1}$ at room temperature. Dyesensitized solar cell (DSSC) employing the hybrid composite membrane with PEO and 10 wt % $SiO_2$ exhibited an open circuit voltage of 0.77 V and a short circuit current of 10.78 $mAcm^{-2}$ at an incident light intensity of 100 $mWcm^{-2}$, yielding a conversion efficiency of 5.2%. DSSC employing the hybrid composite membrane showed more stable photovoltaic performance than that of the DSSC assembled with liquid electrolyte.

• Membrane Journal
• /
• v.32 no.6
• /
• pp.427-441
• /
• 2022

Polymer electrolyte membrane (PEM) serving as a separator that can prevent the permeation of unreacted fuels as well as an electrolyte that selectively transports protons from the anode to the cathode has been considered a key component of polymer electrolyte membrane fuel cell (PEMFC). The perfluorinated sulfonic acid-based PEMs, represented by Nafion®, have been commercialized in PEMFC systems due to their high proton conductivity and chemical stability. Nevertheless, these PEMs have several inherent drawbacks including high manufacturing costs by the complex synthetic processes and environmental problems caused by producing the toxic gases. Although numerous studies are underway to address these drawbacks including the development of sulfonated hydrocarbon polymer-based PEMs (SHP-PEMs), which can easily control the polymer structures, further improvement of PEM performances and durability is necessary for practical PEMFC applications. Therefore, this study focused on the various strategies for the development of SHP-PEMs with outstanding performance and durability by 1) introducing cross-linked structures, 2) incorporating organic/inorganic composites, and 3) fabricating reinforced-composite membranes using porous substrates.