Role In Performance Of Electrodes Research Articles

A Review of the Carbon-Based Solid Transducing Layer for Ion-Selective Electrodes.

As one of the key components of solid-contact ion-selective electrodes (SC-ISEs), the SC layer plays a crucial role in electrode performance. Carbon materials, known for their efficient ion-electron signal conversion, chemical stability, and low cost, are considered ideal materials for solid-state transducing layers. In this review, the application of different types of carbon materials in SC-ISEs (from 2007 to 2023) has been comprehensively summarized and discussed. Representative carbon-based materials for the fabrication of SC-ISEs have been systematically outlined, and the influence of the structural characteristics of carbon materials on achieving excellent performance has been emphasized. Finally, the persistent challenges and potential opportunities are also highlighted and discussed, aiming to inspire the design and fabrication of next-generation SC-ISEs with multifunctional composite carbon materials in the future.

Investigation of Xanthan Gum and Carboxymethyl Cellulose Binders for the Silicon Anode of Lithium-Ion Batteries

The binder is known to play an important role in the cycle stability of silicon-based anodes for lithium-ion batteries. Nature-derived biopolymers such as sodium carboxymethyl cellulose (NaCMC) and xanthan gum (XG) are a promising class of binders that offer several advantages over traditional polyvinylidene fluoride (PVDF). Advantages include better contact between silicon particles and the ability to process the electrodes using water as a solvent. While many studies have explored the fundamental properties of these biopolymer binders and their interaction with silicon, there has been little research on the use of these binders under practical loadings (such as ∼2 mg Si cm−2 and <10 wt% binder). Herein, we compare the electrochemical performance of both NaCMC and XG-based silicon electrodes with a low binder content. Si-binder interactions and their role in electrode performance are revealed with XPS, SEM, and EDX. In addition, we report the results of both a high-silicon (80 wt% Si) and a practical low-silicon (20 wt% Si) composite electrode while using silicon nano powder prepared by industrial-scale synthesis. It is found that NaCMC consistently outperforms XG as a binder, which is attributable to superior cohesion within the electrode.

Influence of the PTFE Membrane Thickness on the CO2 Electroreduction Performance of Sputtered Cu‐PTFE Gas Diffusion Electrodes

AbstractGas diffusion electrodes (GDE) obtained by sputtering metal films on polytetrafluoroethylene (PTFE) membranes are among the most performant electrodes used to electrochemically reduce CO2. The present work reveals several essential aspects for fabricating performant PTFE‐based gas diffusion electrodes (GDEs) for CO2 electroreduction (CO2R). We show that adding an additive layer (a mixture of carbon and Nafion™ or Nafion™ only) is required for stabilizing the metal catalyst film (Cu), deposited via sputtering on the PTFE membrane, during the CO2R experiments. We found that the PTFE membrane thickness used in the GDE fabrication plays an essential role in electrode performance. The quantification of the products formed during the CO2R conducted in a flow‐cell electrolyzer revealed that on thinner membranes, CO2R is the dominant process while on thicker ones, the H2 formation is promoted. Thus, the PTFE membrane influences the CO2 transport to the catalyst layer and can be used to promote the CO2R while maintaining a minimum H2 production.

Reconstruction and optimization of LSCF cathode microstructure based on Kinetic Monte Carlo method and Lattice Boltzmann method

Solid phase sintering is a critical process for fabricating mixed ionic and electronic conductivity (MIEC) electrodes. In this study, the microstructures of MIEC electrodes are numerically reconstructed by a Kinetic Monte Carlo method. The performance of the reconstructed MIEC electrodes is then evaluated by a pore scale Lattice Boltzmann model. The present study provides the first comprehensive assessment of local O2 partial pressure on electrode performance. It is found that ohmic loss tends to play remarkable roles at a low O2 partial pressure of pO2<0.1bar. As insufficiency of O2 is almost unavoidable in the SOFC stack, the influence of local O2 partial pressure on ionic conductivity should be considered in LSCF modeling. Another important finding is that the initial states of compact powder have a profound impact on the electrode performance. Small initial grain size and irregular particles both contribute to generate large reaction area after sintering thereby decrease activation loss. It is also found that compact powder consistency even plays a more important role in electrode performance than particle size. The study also provides deep insight into influence of sintering process. The effective conductivity of electrode is mainly controlled by the enhancement of electrode connectivity. Subsequently, nanostructured SOFC electrodes by infiltration/impregnation are reconstructed evaluated numerically. The infiltrated electrodes demonstrate improved performance and significantly promote uniformity of reaction rates. The present study forms a solid foundation for optimization of the fabrication procedures to improve the fuel cell performance.

Surface enhanced 3D rGO hybrids and porous rGO nano-networks as high performance supercapacitor electrodes for integrated energy storage devices

Rapid advancements in technology has led to urgent requirement for mobile and portable power sources. Achieving self-sustainability using renewable energy sources using such devices provide an added advantage. Electrode materials play a critical role in performance of these devices, while the surface morphology of the electrode material play a crucial role in performance of electrodes themselves. Here we report fabrication of a flexible, all-solid state high performance hybrid supercapacitor using the 3D dendritic cell like nanostructures of Ni–Co LDH@rGO as cathode and novel crumpled leaf like rGO nano porous networks as anode. PVA-KOH gel is used as solid-state gel electrolyte. The fabricated supercapacitor is incorporated with a solar cell to demonstrate a self sustainable power pack The working potential window obtained is ∼1.4–1.8V. The asymmetric and hybrid assembly of the device enables in achieving high energy and power density. The energy and power density of the assembled supercapacitor is ∼58.4 Wh/Kg and ∼374 W/kg respectively at a current density of 0.5 A/g. The Coulombic efficiency is approximately 100% and suggests superior performance of the supercapacitor. Our experiments demonstrate the potential use of graphene based materials for powering wearable and portable electronic devices in a self sustainable manner.

(Invited) Titanate-Based Electrodes for Solid Oxide Cells

This talk describes solid oxide cell electrodes based on Sr(Ti0.3Fe0.7)O3 (STF). For oxygen electrodes, the substitution of a small amount of Co (up to 15%) for Fe substantially reduces polarization resistance, e.g., from 0.7 to 0.2 Wcm2in air at 600 oC.[1] The oxygen transport rate coefficients and polarization resistance RP values are increased by a factor of ~ 3 times by Co substitution, and are generally much better than those for the widely used (La,Sr)(Co,Fe)O3 electrodes. Electrode and cell stability are markedly improved compared to LSCF cathodes. PrOxinfiltration into Co-substituted STF yields a substantial reduction in RP , to values useful for low-temperature (<600 oC) solid oxide cells. For fuel electrodes, Sr(Ti0.3Fe0.7)O3 yields good performance at ≥ 800 oC and hydrogen-rich fuels, but the performance suffers at lower temperature and in depleted fuel due to slow H2 dissociative adsorption.[2] The substitution of 7% Ni for Fe in Sr deficient STF substantially reduces RP under these conditions.[3] The Ni substitution results in the exsolution of Ni and Fe from the perovskite, yielding Ni-Fe nanoparticles that decorate the oxide electrode surfaces and promote hydrogen dissociative adsorption. Perovskite stoichiometry, which changes during exsolution, is found to play an important role in electrode performance; initially Sr-deficient anodes yield much lower RP values. RP values for Ni-substituted STF are comparable those of Ni-YSZ anodes. References：[1] S.-L. Zhang, H. Wang, M.Y. Lu, A.-P. Zhang, L.V. Mogni, Q. Liu, C.-X. Li, C.-J. Li, S.A. Barnett, Energy & Environmental Science (2018, DOI: 10.1039/C8EE00449H). [2] T. Zhu, D.E. Fowler, K.R. Poeppelmeier, M. Han, S.A. Barnett, Journal of The Electrochemical Society 163 (2016) (8) F952. [3] T. Zhu, H.E. Troiani, L.V. Mogni, M. Han, S.A. Barnett, Joule (2018) 10.1016/j.joule.2018.02.006.