Cobalt oxides-sheathed cobalt nano flakes to improve surface properties of carbonaceous electrodes utilized in microbial fuel cells

Mohamed, Hend Omar,Abdelkareem, Mohammad Ali,Obaid, M.,Chae, Su-Hyeong,Park, Mira,Kim, Hak Yong,Barakat, Nasser A.M. Elsevier 2017 Chemical engineering journal Vol.326 No.-

<P><B>Abstract</B></P> <P>A novel nanoflakes of cobalt sheathed with cobalt oxide is electrodeposited on four different carbonaceous anodes; carbon cloth (CC), carbon paper (CP) graphite (G) and activated carbon (AC), to introduce as high-performance anodes of microbial fuel cell (MFC). Interestingly, characterizations results indicated that novel metallic nanoflakes that sheathed by a thin layer of cobalt oxide were formed on the surface of the different anode materials. Moreover, using a simple and effective electrodeposition technique for fabricating of cobalt/cobalt oxide nanoflakes is introduced to overcome the hydrophobicity and the interfacial electron transfer of the anodes. The thin layer of cobalt/cobalt oxide nanoflakes significantly enhanced the microbial adhesion, the wettability of the anode surface and decrease the electron transfer resistance. Alternatively, the toxicity risk of the pure cobalt is overcome by the cobalt oxide layer. The application of the modified anodes in an air-cathode MFCs fed by industrial wastewater resulted in a significant improving in cell performance for the different anode materials. Where, the observed increasing in the power was 103, 137, 173 and 71% for the CC, CP, G and AC electrodes, respectively. This proposed treatment technique represented a high-performance, excellent microbial adhesion, easy fabrication and scale-up anodes for MFC.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cobalt oxides-sheathed cobalt nano flakes was deposited on anodes using electrodeposition. </LI> <LI> The modified anodes were used in MFC to treat the wastewater and produce energy. </LI> <LI> The modified anodes shows promising results in single air-cathode MFC. </LI> <LI> The results of the modified anodes were strongly enhanced compared to the pristine anodes. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Suppression of dendrites and granules in surface-patterned Li metal anodes using CsPF₆

Kim, Seokwoo,Choi, Junyoung,Lee, Hongkyung,Jeong, Yong-Cheol,Lee, Yong Min,Ryou, Myung-Hyun Elsevier 2019 Journal of Power Sources Vol.413 No.-

<P><B>Abstract</B></P> <P>Unexpected Li deposition during plating, which causes low Coulombic efficiency and safety issues, limits the use of Li metal as an anode in commercial secondary batteries. With the recently developed micro-patterned Li metal anodes, dendrite formation during high current Li plating (2.4 mA cm<SUP>−2</SUP>) has successfully been reduced, as Li ions are guided into the patterned holes. However, the uncontrolled formation of granular Li is still observed in this material. To overcome these shortcomings, we have introduced cesium hexafluorophosphate into micro-patterned Li metal anodes. This additive employs the self-healing electrostatic shield mechanism to effectively reduce the formation of granular Li and Li dendrites, thereby significantly improving the electrochemical performance of the anodes even when only small amounts (0.05 M) of electrolyte are used. Our experiments revealed that batteries employing surface-patterned Li metal anodes with cesium hexafluorophosphate maintained 88.7% (96.6 mAh g<SUP>−1</SUP>) of their initial discharge capacity after the 900<SUP>th</SUP> cycle (Charging current density: C/2, 0.6 mA cm<SUP>−2</SUP>, Discharging current density: 1C, 1.2 mA cm<SUP>−2</SUP>), which is three times higher than the capacity observed with surface-patterned Li metal anodes without the additive (discharge capacity starts to decrease from 300 cycles).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Cesium hexafluorophosphate was introduced to surface-patterned Li metal anodes. </LI> <LI> Cs<SUP>+</SUP> ions and patterned Li showed synergistic improvement in cycle performance. </LI> <LI> Cs<SUP>+</SUP> ions hindered the formation of granule and dendrites of patterned Li metal. </LI> <LI> Cs<SUP>+</SUP> ions stabilized the morphology of the surface-patterned Li metal anodes during cycling. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

<i>In operando</i> X-ray diffraction strain measurement in Ni₃Sn₂ – Coated inverse opal nanoscaffold anodes for Li-ion batteries

Glazer, Matthew P.B.,Wang, Junjie,Cho, Jiung,Almer, Jonathan D.,Okasinski, John S.,Braun, Paul V.,Dunand, David C. Elsevier 2017 Journal of Power Sources Vol.367 No.-

<P><B>Abstract</B></P> <P>Volume changes associated with the (de)lithiation of a nanostructured Ni<SUB>3</SUB>Sn<SUB>2</SUB> coated nickel inverse opal scaffold anode create mismatch stresses and strains between the Ni<SUB>3</SUB>Sn<SUB>2</SUB> anode material and its mechanically supporting Ni scaffold. Using <I>in operando</I> synchrotron x-ray diffraction measurements, elastic strains in the Ni scaffold are determined during cyclic (dis)charging of the Ni<SUB>3</SUB>Sn<SUB>2</SUB> anode. These strains are characterized using both the center position of the Ni diffraction peaks, to quantify the average strain, and the peak breadth, which describes the distribution of strain in the measured volume. Upon lithiation (half-cell discharging) or delithiation (half-cell charging), compressive strains and peak breadth linearly increase or decrease, respectively, with charge. The evolution of the average strains and peak breadths suggests that some irreversible plastic deformation and/or delamination occurs during cycling, which can result in capacity fade in the anode. The strain behavior associated with cycling of the Ni<SUB>3</SUB>Sn<SUB>2</SUB> anode is similar to that observed in recent studies on a Ni inverse-opal supported amorphous Si anode and demonstrates that the (de)lithiation-induced deformation and damage mechanisms are likely equivalent in both anodes, even though the magnitude of mismatch strain in the Ni<SUB>3</SUB>Sn<SUB>2</SUB> is lower due to the lower (de)lithiation-induced contraction/expansion.</P> <P><B>Highlights</B></P> <P> <UL> <LI> Lithiation-induced strains quantified in a Ni<SUB>3</SUB>Sn<SUB>2</SUB> inverse opal anode <I>in operando</I>. </LI> <LI> Lithiation induces compressive average strains in Ni inverse opal scaffold. </LI> <LI> Ni inverse opal scaffold strain distribution reversibly broadens upon lithiation. </LI> <LI> Three measured volumes show similar cyclic strain averages and distributions. </LI> <LI> Ni<SUB>3</SUB>Sn<SUB>2</SUB> measured cyclic strains are similar to prior Si inverse opal anode studies. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

아연-공기 전지용 음극재의 자가방전 억제 효과

정민서,조용남,Jung, Min Seo,Jo, Yong Nam 한국재료학회 2020 한국재료학회지 Vol.30 No.12

For zinc-air batteries, there are several limitations associated with zinc anodes. The self-discharge behavior of zinc-air batteries is a critical issue that is induced by corrosion reaction and hydrogen evolution reaction (HER) of zinc anodes. Aluminum and indium are effective additives for controlling the hydrogen evolution reaction as well as the corrosion reaction. To enhance the electrochemical performances of zinc-air batteries, mechanically alloyed Zn-Al and Zn-In materials with different compositions are successfully fabricated at 500rpm and 5h milling time. Investigated materials are characterized by X-ray diffractometer (XRD), field emission scanning electron microscope (FE-SEM), and energy dispersive spectrometer (EDS). Alloys are investigated for the application as novel anodes in zinc-air batteries. Especially, the material with 3 wt% of indium (ZI3) delivers 445.37 mAh/g and 408.52 mAh/g of specific discharge capacity with 1 h and 6 h storage, respectively. Also, it shows 91.72 % capacity retention and has the lowest value of corrosion current density among attempted materials.

Effects of manganese substitution at the B-site of lanthanum-rich strontium titanate anodes on fuel cell performance and catalytic activity

Rath, Manas K.,Ahn, Byung-Guk,Choi, Byung-Hyun,Ji, Mi-Jung,Lee, Ki-Tae Elsevier 2013 Ceramics international Vol.39 No.6

<P><B>Abstract</B></P> <P>Sr<SUB>0.4</SUB>La<SUB>0.6</SUB>Ti<SUB>1−<I>x</I> </SUB>Mn<SUB> <I>x</I> </SUB>O<SUB>3−<I>δ</I> </SUB> with rhombohedral structure has been investigated in terms of their electrochemical performance, redox stability, and electro-catalytic properties for solid oxide fuel cell anodes. The performance of Sr<SUB>0.4</SUB>La<SUB>0.6</SUB>Ti<SUB>1−<I>x</I> </SUB>Mn<SUB> <I>x</I> </SUB>O<SUB>3−<I>δ</I> </SUB> anodes for solid oxide fuel cells strongly depends on the Mn substitution at the B-site of the perovskites. Electrical conductivity of Sr<SUB>0.4</SUB>La<SUB>0.6</SUB>Ti<SUB>1−<I>x</I> </SUB>Mn<SUB> <I>x</I> </SUB>O<SUB>3−<I>δ</I> </SUB> increases with increasing Mn content. X-ray photoelectron spectroscopy analysis reveals that the amount of Mn<SUP>3+</SUP> and Ti<SUP>3+</SUP>, which is an electronic charge carrier, increases with Mn doping. The reduced anode powders with high Mn/Ti ratio show oxygen storage capability and a low carbon deposition rate. Linear thermal expansion coefficients of Sr<SUB>0.4</SUB>La<SUB>0.6</SUB>Ti<SUB>1−<I>x</I> </SUB>Mn<SUB> <I>x</I> </SUB>O<SUB>3−<I>δ</I> </SUB> anodes range from 9.46×10<SUP>−6</SUP> K<SUP>−1</SUP> to 11.3×10<SUP>−6</SUP> K<SUP>−1</SUP>. The maximum power densities of the single cell with the Sr<SUB>0.4</SUB>La<SUB>0.6</SUB>Ti<SUB>0.2</SUB>Mn<SUB>0.8</SUB>O<SUB>3−<I>δ</I> </SUB> anode in humidified H<SUB>2</SUB> and CH<SUB>4</SUB> at 800°C are 0.29Wcm<SUP>−2</SUP> and 0.24Wcm<SUP>−2</SUP>, respectively.</P>

Facile synthesis of polynorbornene-based binder through ROMP for silicon anode in lithium-ion batteries

Preman Anjali Nagapadi,Lim Ye Eun,Lee Seungjae,Kim Seokjun,Kim Il Tae,안석균 한국화학공학회 2023 Korean Journal of Chemical Engineering Vol.40 No.10

Although binders are a minor component in battery electrodes, they can improve the electrochemical performance considerably, particularly in conversion-type electrodes, such as the silicon (Si) anode, which has volume expansion problems. Although numerous binders are reported for Si anode, less attention has been paid to those prepared through controlled polymerization, which can allow the preparation of well-defined polymers. Herein, we report the facile synthesis of carboxylic acid-functionalized polynorbornene (CA-PNB) via ring-opening metathesis polymerization (ROMP) and apply this as the binder for Si anode. Owing to the ultrafast polymerization kinetics of ROMP, a high molecular weight polymer (∼279 kDa) with narrow dispersity (Đ=1.07) was readily prepared within 30 min. The resulting CA-PNB was used as the binder for a Si nanoparticle anode, which exhibits an initial coulombic efficiency of 81% and a specific capacity of 1,654 mAh g−1 after 100 cycles at 0.5 A g−1. These values outperform the Si anodes prepared using conventional polyvinylidene difluoride and carboxymethyl cellulose binders, probably due to the abundant carboxylic acid groups in the CA-PNB that offer stronger interactions with the Si surface. Since ROMP is a highly efficient polymerization tool to produce polymers with tailored architectures and controlled monomer sequences, this method will be valuable for the rational molecular design of high-performance binders for battery electrodes.

Sr_0.92Y_0.08TiO_3-δ/Sm_0.2Ce_0.8O_2-δ anode for solid oxide fuel cells running on methane

Kim, H.S.,Yoon, S.P.,Yun, J.W.,Song, S.A.,Jang, S.C.,Nam, S.W.,Shul, Y.G. Pergamon Press ; Elsevier Science Ltd 2012 International journal of hydrogen energy Vol.37 No.21

Yttria-doped strontium titanium oxide (Sr<SUB>0.92</SUB>Y<SUB>0.08</SUB>TiO<SUB>3-δ</SUB>; SYT) was investigated as an alternative anode material for solid oxide fuel cells (SOFCs). The SYT synthesized by the Pechini method exhibits excellent phase stability during the cell fabrication processes and SOFC operation and good electrical conductivity (about 0.85 S/cm, porosity 30%) in reducing atmosphere. The performance of SYT anode is characterized by slow electrochemical reactions except for the gas-phase diffusion reactions. The cell performance with the SYT anode running on methane fuel was improved about 5 times by SDC film coating, which increased the number of reaction sites and also accelerated electrochemical reaction kinetics of the anode. In addition, the SDC-coated SYT anode cell was stably operated for 900 h with methane. These results show that the SDC-coated SYT anode can be a promising anode material for high temperature SOFCs running directly on hydrocarbon fuels.

Recycling oil-extracted microalgal biomass residues into nano/micro hierarchical Sn/C composite anode materials for lithium-ion batteries

Song, Danoh,Park, Jinseok,Kim, Kyuman,Lee, Lee Seol,Seo, Jung Yoon,Oh, You-Kwan,Kim, Yong-Joo,Ryou, Myung-Hyun,Lee, Yong Min,Lee, Kyubock Pergamon Press 2017 Electrochimica Acta Vol. No.

<P><B>Abstract</B></P> <P>We introduce a novel approach for the high-value production of nano/micro hierarchical structured Sn anodes for lithium-ion batteries (LIBs) by utilizing microalgal biomass residues that collaterally form during oil extraction for biofuel production. The Sn/C composites made from the oil-extracted microalgal biomass residues (the extracted Sn/C) exhibit the following advantages as high-energy-density anodes: 1) a homogeneous distribution of Sn nanoparticles in the carbon matrix (Sn/C), which efficiently relieves the strain caused by volume changes of the active materials; 2) a high porosity of Sn/C composites; and 3) a homogeneous distribution of the hetero elements N and P in the carbon matrix. Overall, the extracted Sn/C exhibit improved electrochemical performance in LIBs compared with the Sn/C composites made from the microalgal biomass residues without oil extraction (non-extracted Sn/C). The extracted Sn/C have improved rate capabilities (160.0 and 72.9mAhg<SUP>−1</SUP> for the extracted Sn/C and the non-extracted Sn/C, respectively, at the 80th cycle, 3.5Ag<SUP>−1</SUP>) and improved cycle performances (511.7 and 493.2mAhg<SUP>−1</SUP> for the extracted Sn/C and the non-extracted Sn/C, respectively, at the 300th cycle, 200mAg<SUP>−1</SUP>).</P> <P><B>Highlights</B></P> <P> <UL> <LI> Nano/micro hierarchical Sn/C anode materials are prepared from biomass residues. </LI> <LI> Oil-extraction process guarantees a cost-effective synthesis strategy. </LI> <LI> Oil-extraction process provides nano/micro hierarchical Sn/C anode materials. </LI> <LI> Nano/micro hierarchical Sn/C anode materials show improved rate capability. </LI> </UL> </P> <P><B>Graphical abstract</B></P> <P>[DISPLAY OMISSION]</P>

Carbyne Bundles for a Lithium-ion-battery Anode

박민우,이훈경 한국물리학회 2013 THE JOURNAL OF THE KOREAN PHYSICAL SOCIETY Vol.63 No.5

Carbyne, an infinite chain of sp-bonded carbon atoms, may be an effective material for energy storage applications, such as lithium-ion batteries, owing to its extremely large surface area (∼11000m2 g−1). Using first principles density functional calculations, we explored the possibilities of carbyne bundles for use in lithium-ion-battery anodes. A composite of a stable Li-intercalated carbyne bundle has the formula C6Li13. The open circuit voltage of the battery made with a carbyne bundle ranges from ∼0.3 to ∼0.9 V with changing concentration x (C6Lix), meeting the voltage requirement for anodes. The Li-intercalated carbyne bundle (C6Li13) possesses specific and volumetric capacities of ∼4840 mAh g−1 and ∼2038 mAh cm−3, respectively, which are much greater than the corresponding values for graphite of ∼370 mAh g−1 and ∼820 mAh cm−3. We propose that carbyne bundles can serve as high-capacity lithium-ion- battery anodes.

Ni-Fe/YSZ 코어-쉘 구조 연료극을 사용한 다전지식 고체산화물 연료전지의 전기화학적 특성

안용태,지미정,황해진,이민진,홍선기,강영진,최병현,An, Yong-Tae,Ji, Mi-Jung,Hwang, Hae-Jin,Lee, Min-Jin,Hong, Sun-Ki,Kang, Young-Jin,Choi, Byung-Hyun 한국세라믹학회 2014 한국세라믹학회지 Vol.51 No.4

An Ni-Fe/YSZ core-shell structured anode for uniform microstructure and catalytic activity was synthesized. Flat tubular segmented-in-series solid oxide fuel cell-stacks were prepared by decalcomania method using synthesized anode powder. The Ni-Fe/YSZ core-shell anode exhibited better electrical conductivity than a commercially available Ni-YSZ cermet anode. Also power output increased by 1.3 times with a higher open circuit voltage. These results can be attributed to the uniformly distributed Ni particles in the YSZ framework. The impedance spectra of a Ni-Fe/YSZ core-shell anode showed comparable reduced ohmic resistance similar to those of the commercially available Ni-YSZ cermet anodes.