Electrochemical Energy Technologies Research Articles

Single-atom platinum promotes Cu(I)/Cu(II) redox loop of Cu aerogels for efficient glucose electrooxidation

Glucose oxidation reaction (GOR) is emerging as a promising alternative to the sluggish anodic oxygen evolution reaction for hydrogen production in energy-saving water electrolysis. Cu-based electrocatalysts hold natural superiority for GOR, which is limited by the slow Cu(I)/Cu(II) redox loop. Here, we synthesize Cu50Pt aerogels with Pt single atom (SA) to enhance GOR activity with an accelerated Cu(I)/Cu(II) redox loop compared to Cu aerogels. Experimental and theoretical investigations elucidate that Pt SA boosts the adsorption and activation capacity of OHads, promoting the hydroxylation of Cu(I) into Cu(II) active species through hydroxyl spillover. Moreover, the optimized electronic structure of Cu by Pt SA facilitates the glucose adsorption, the dehydrogenation process of C5H11O5CHO* to C5H11O5CO* and the release of products, thus promoting the hydroxyl deintercalation of Cu(II) sites into Cu(I). Notably, the Pt SA-assisted plasma effect of Cu further enhances the GOR activity and reduces the power consumption of hydrogen production by promoting the Cu(I)/Cu(II) redox loop. This work provides new insights into high-performance biomass electrooxidation catalysts via accelerating the redox cycle of reactive metal for electrochemical energy technologies.

Incorporation of Ag in Co9S8-Ni3S2 for Predominantly Enhanced Electrocatalytic Activities for Oxygen Evolution Reaction: A Combined Experimental and DFT Study.

Electrodeposition of abundant metals to fabricate efficient and durable electrodes indicate a viable role in advancing renewable electrochemical energy tools. Herein, we deposit Co9S8-Ag-Ni3S2@NF on nickel foam (NF) to produce Co9S8-Ag-Ni3S2@NF as a exceedingly proficient electrode for oxygen evolution reaction (OER). The electrochemical investigation verifies that the Co9S8-Ag-Ni3S2@NF electrode reveals better electrocatalytic activity to OER because of its nanoflowers' open-pore morphology, reduced overpotential (η10=125 mV), smaller charge transfer resistance, long-term stability, and a synergistic effect between various components, which allows the reactants to be more easily absorbed and subsequently converted into gaseous products during the water electrolysis route. Density functional theory (DFT) calculation as well reveals the introduction of Ag (222) surface into the Co9S8 (440)-Ni3S2 (120) structure increases the electronic density of states (DOS) per unit cell of a system and increases the electrocatalytic activity of OER by considerably lowering the energy barriers of its intermediates. This study provides the innovation of employing trimetallic nanomaterials immobilized on a conductive, continuous porous three-dimensional network formed on a nickel foam (NF) substrate as a highly proficient catalyst for OER.

Oxygen-enriched Fe-N-C electrocatalyst for efficient oxygen reduction reaction

The cathode's oxygen reduction reaction (ORR) plays a crucial role in a variety of fuel cells. Developing affordable and efficient non-precious electrocatalysts for the ORR poses a major hurdle in the realm of electrochemical energy technologies. This work presents a transition metal-based catalyst, Fe-ONC, in which Fe is loaded in an oxygen-enriched nitrogen-doped carbon (NC) material. Oxygen enrichment of the catalyst was achieved by a pre-oxidation strategy. The XPS analysis reveals that Fe-ONC exhibits a higher abundance of oxidized species. The Fe of Fe-ONC exists in the form of Fe3O4 particles and Fe-Nx, respectively, which are uniformly distributed in the NC. The even spread of iron sites and the plentiful presence of oxygen-rich species are key factors in the superior ORR efficiency of Fe-ONC. Fe-ONC's half-wave potential (E1/2) in an alkaline environment (0.1 M KOH) stands at 0.891 V, markedly surpassing the standard commercial Pt/C value (0.840 V). Additionally, Fe-ONC demonstrated enhanced longevity and resistance to ethanol in comparison to commercially available Pt/C. Fe-ONC's outstanding efficacy highlights its potential as an alternative to precious metal catalysts. The document outlines a plan for creating ORR catalytic materials that are sustainable, economical, and efficient.

Tuning Oxygen Evolving Catalytic Activity of a Precious Metal-Free Nickel Boride by a Cost-Effective Method

The production of hydrogen (H2) by electrochemical water splitting [Green Hydrogen (Green H2)], if driven by green electricity, has attracted considerable interest as an alternative sustainable energy carrier, e.g., in fuel cells for electricity or power and heat generation [1]. However, the lack of satisfactory and cheap electrocatalysts (ECs) to drive the vital electrochemical reactions of hydrogen evolution (HER) and oxygen evolution (OER) in water splitting is the biggest challenge for this technology.Currently, the most advanced electrocatalysts for the two half-reactions of water electrolysis (HER and OER) are noble metal-based materials [2]. Despite the excellent catalytic properties of these noble metal catalysts, their high cost, and scarcity make their commercial use both uneconomical and impractical in low temperature water electrolysis (LT-WE) systems at industrial scale for green H2 as a clean energy alternative to cheaper fossil fuels[3]. In addition to addressing this issue by the development of precious-material-based with a low-loading of precious metal elements, the development of desirable and high-efficiency electrocatalysts (ECs) based on earth-abundant metal elements materials is paramount. However, their catalytic activity is often limited by poor electron transfer, low conductivity, low stability, and small surface area of these materials. Thus, it is crucial to develop earth-abundant metal elements-based materials that are more cost-effective to reduce the high cost of active catalysts for water electrolysis. Although several low-cost materials have already been designed, the potential required for the practical application of water splitting is still very high compared to the theoretical potential (1.23 V), which means that much energy is consumed, which theoretically could be reduced. Due to their remarkable advanced charge transfer and durability for water oxidation in alkaline media, electrocatalysts derived from metal borides-based materials have received a lot of attention as new high-performance catalysts for water oxidation.[4] These properties stem from the multi-dimensional covalent bonding of the metalloid with the surrounding metal atoms.We present here an approach to tune the OER of transition metal borides (TMBs) using the cost-effective and less energy-consuming method that is nevertheless a highly efficient material for OER (Fig. 1). We have developed a low-cost, rational and easily scalable method to enhance the catalytic activity of nickel boride (Ni–B), which requires an annealing process to optimize the catalytic activity. However, this method may have limited applicability on a large scale as it requires a highly inert environment and high-temperature treatment of Ni–B catalysts. We also elucidate a structure-activity relationship using scale-bridging techniques such as TEM and electrochemical characterization. The developed based on non-noble electrocatalysts are prepared by a simple method of chemical reduction of transition metal elements with boron in aqueous solution. The production is a one-step process and the material does not require any further treatment, yet this material shows comparable activity to the state of the art (precious metal-based materials) for OER in alkaline solution at a selected current density. This improved catalytic performance is further corroborated by the microstructural investigations in the TEM. The nanoparticles obtained have an improved porous structure compared to Ni–B and thus provide more available sites for the surface reactions and hence for the catalytic performance of the material. Furthermore, it is shown that activation enables the morphological and structural changes, while some transition metal elements act as sacrificial elements to provide more accessible and stable sites for oxygen-forming centers. This paves the way for a better understanding of metal boride-derived electrocatalysts for water oxidation, a crucial chemical reaction in water electrolysis and other electrochemical energy technologies. Acknowledgements: This project has received funding from the European Union’s Horizon 2020 research and innovation program under the Marie Skłodowska-Curie grant agreement No 945422. We acknowledge the use of the DFG-funded Micro-and Nanoanalytics Facility (MNaF) at the University of Siegen (INST 221/131-1).

Corrosion and Protection of Electrocatalysts toward Advanced Energy Technologies

AbstractHigh‐efficiency electrocatalysts play an important role in clean energy conversion technologies. Generally, electrocatalysts in different environments, including voltage, acid, and alkali electrolytes, are more susceptible to corrosion, which will induce structural and performance changes. Based on the latest achievements in the corrosion and protection of electrocatalysts in advanced energy technologies, this review mainly studies the application of various corrosion strategies to construct superior electrocatalysts, including chemical etching, metal corrosion transformation, and corrosion reconstruction, and their affecting factors are also appraised and summarized. To improve the stability of electrocatalysts, various corrosion inhibition strategies, such as carrier improvement and composition regulation accompanied by structure optimization, are reviewed. In addition, the application of catalyst corrosion in electrochemical energy technologies is examined from the perspective of the structure‐activity‐performance relationship. In the end, this article concludes the perspective and challenges of electrocatalyst corrosion in energy conversion and storage technologies. This article provides insights and directions for designing electrocatalysts with high efficiency and low corrosion, which is beneficial for developing corrosion chemistry for sustainable energy technologies.

Atomic Molybdenum Nanomaterials for Electrocatalysis.

As a sustainable energy technology, electrocatalytic energy conversion requires electrocatalysts, which greatly motivates the exploitation of high-performance electrocatalysts based on nonprecious metals. Molybdenum-based nanomaterials have demonstrated promise as electrocatalysts because of their unique physiochemical and electronic properties. Among them, atomic Mo catalysts, also called Mo-based single-atom catalysts (Mo-SACs), have the most accessible active sites and tunable microenvironments and are thrivingly explored in various electrochemical conversion reactions. A timely review of such rapidly developing topics is necessary to provide guidance for further exploration of optimized Mo-SACs toward electrochemical energy technologies. In this review, recent advances in the synthetic strategies for Mo-SACs are highlighted, focusing on the microenvironment engineering of Mo atoms. Then, the representative achievements of their applications in various electrocatalytic reactions involving the N2, H2O, and CO2 cycles are summarized by combining experimental and computational results. Finally, prospects for the future development of Mo-SACs in electrocatalysis are provided and the key challenges that require further investigation and optimization are highlighted.

Biologically templated formation of Cobalt-Phosphide-Graphene hybrids with charge redistribution for efficient hydrogen evolution

Developing highly efficient and sustainable hydrogen evolution reaction (HER) electrocatalysts is important for the practical application of emerging energy technologies. The spherical structure and phosphorus-rich properties of Chlorella can facilitate the construction of comparable transition metal phosphide electrocatalysts. Here, a microorganism template strategy is proposed to construct a cobalt-phosphide-graphene hybrid. Chlorella can absorb metal ions, and the generated rough spherical nanoparticles are uniformly distributed around the reduced graphene oxide nanosheets. This designed catalyst has comparable HER performance in acidic electrolytes and needs an overpotential of only 153 mV at a current density of 10 mA cm−2. The experimental and density functional theory results imply that the charge redistribution between Co2P and pyrrole-N is the key factor in enhancing the HER activity. The induced electron aggregation at the N and P sites can serve as a key active site for absorbing the adsorbed hydrogen atom intermediate to accelerate the HER process, contributing to the active sites of Co2P- and pyrrole-N-doped carbon with 0 eV hydrogen adsorption free energy. This work provides a broad idea for synthesizing advanced catalysts by a biological template approach, facilitating the innovative integration of biology and emerging electrochemical energy technologies.

Robust and highly proton conductive COF composite membranes for fuel cell and electrochemical hydrogen compression

Robust and highly conductive proton exchange membrane (PEM) is the unremitting pursuit of numerous electrochemical energy technologies such as fuel cell and the emerging electrochemical hydrogen compression. Ionic covalent organic framework nanosheets (iCONs) with long-range ordered nanochannels and abundant ionic groups show substantial potential as next-generation PEM materials. However, it is challenging to assemble iCONs into membranes with both robustness and flexibility due to the electrostatic repulsion and rigid framework. Herein, we propose a hydrogen-bond binding strategy to fabricate sulfonic iCON (SCON) composite membranes by co-assembling tannic acid (TA) nanoaggregates and SCONs. The abundant and dynamically reversible hydrogen-bond interactions introduced by TA nanoaggregates establish effective linkage between SCONs and allow some restricted movements, endowing membranes with remarkably improved mechanical properties. The stacked SCONs construct long-range ordered nanochannels with well-arranged sulfonic groups in membranes, and the hydrogen-bond networks further facilitate the proton transport through Grotthuss mechanism. Consequently, TA/SCON composite membranes displays significantly enhanced tensile strength of 101.9 MPa, good flexibility and high proton conductivity of 490.1 mS cm−1 at 80 °C and 100 % RH simultaneously. This hydrogen-bond binding strategy offers a promising approach to fabricate robust and highly conductive PEMs for various proton-conducting applications.

Structural reconstruction of electrocatalysts

Efficient and durable electrocatalysts are essential for achieving high electrocatalytic efficiency in electrocatalytic reactions, forming the bedrock of effective electrochemical energy technologies. Electrocatalysis is a complex process, marked by intricate reaction system and crucial interfacial interactions, leading to diverse degrees of reconstruction changes in electrocatalysts, affecting both catalytic capabilities and structural integrity. This review delves into the development and prospects of electrocatalyst reconstruction within the electrochemical energy conversion and storage technologies. It elucidates the underlying motivation and mechanism driving reconstruction in various oxidation/reduction reaction systems. Moreover, it elucidates the evolution and comprehension of highly effective electrocatalysts that emerge as a result of this reconstruction phenomenon. The characterizations of catalyst reconstruction are thoroughly examined through the cutting-edge imaging/spectroscopy technologies, enabling dynamic reconstruction tracking and identification. Finally, this work highlights the challenges and opportunities associated with advancing reconstructed electrocatalysts. The primary objectives are to fathom the intricacies of reconstruction and its structural evolution for precise catalyst design. Additionally, it aims to regulate the reconstruction process to enhance the electrocatalyst longevity, stabilize catalytic reactions, and ultimately facilitate the implementation of electrochemical technologies.

High chemical stability poly(oxindole biphenylene)/ZrO2 porous separator for alkaline water electrolysis

Porous separators are essential for alkaline electrochemical energy technologies, such as alkaline water electrolyzers (AWEs). These separators are promising alternatives to dense membranes because they offer the potential for low cost and high ionic conductivity. However, two significant challenges in developing efficient and durable alkaline energy systems are the suppression of hydroxide ions-induced degradation and the reduction of gas permeation in porous separators. Compared to hydrophobic polysulfone (PSF), KOH-doped poly (oxindole biphenylene) (POBP) is a highly stable ion-solvating polymer that can conduct both potassium and hydroxide ions. Building upon this, a series of porous separators based on POBP polymer with different zirconia loads were designed using NIPS to investigate the chemical stability and water electrolysis performance where the Z60 separator exhibits remarkable characteristics, including low area resistance (0.227 Ω cm2), high bubble point pressure (0.813 MPa), low H2 permeability (0.5 L min−1·cm−2) and exceptional 5040 h of ex-situ durability in 6 M KOH at 80 °C. Furthermore, the Z60 diaphragm showed a higher breaking time and lower weight loss after 261 h at 80 °C in the Fenton reagent, with the remaining mass being Z60 was 38 %. Notably, the Z60 diaphragm, when equipped with Ni–Al catalysts, achieved a current density of 0.5 A/cm2 at 1.7 V, which surpasses that of Zirfon (0.5 A/cm2 at 1.8 V). More importantly, when using Ni foam catalysts, the Z60 diaphragm demonstrated stable operation under 0.125 and 0.5 A/cm2 current densities at 80 °C for more than 900 h and 1200 h, significantly improving the durability of the porous separators. The results of this study showed that the blending of POBP can lead to the development of highly chemically stable porous diaphragms, thereby opening up a new avenue for advanced AWEs.

Electro-Chemical Energy Conversion and Storage Systems- Analytical Review

This study emphasises how crucial it is to implement clean energy technology, especially electro-chemical systems, in order to reduce the emission of green-house and fulfil the world's growing energy needs. The study highlights the significance of sustainable resources such as wind and solar electricity. It also examines the difficulties associated with their intermittent nature and proposes changes to consumer behaviour and power producing practices. It talks about current research on candidate materials at the fundamental level and emphasises the crucial role customised materials play in electro-chemical systems. The paper explores the several uses of electro-chemical energy technology, explaining the classifications and operation of fuel cells, batteries, and capacitors, among other devices. The paper concludes by arguing that further advancements in materials and technology are essential to securing a reliable and efficient energy supply in the future.

Disentangling pH Effects on Electrocatalytic Reactions

Electrocatalysis is the key discipline to enable breakthrough advances in electrochemical energy technology and in the conversion of CO2 into renewable fuels and value-added chemicals. However, crucial electrocatalytic reactions are afflicted with sluggish kinetics and low selectivity. The electrolyte plays a vital role for the course of an electrocatalytic reactions and, in this realm, understanding the impact of the local pH is crucial for electrocatalyst development and design. The high interest in this topic in the research community is well-reflected in the recent literature, cf., e.g., Science 2022, 375 (6579). Explanations of pH effects remain controversial, even for the simplest model reactions, i.e., the hydrogen evolution/oxidation reaction and the formic acid oxidation reaction (FAOR), since a complex interplay of multiple interacting factors, centered around the local reaction environment and kinetic effects, must be disentangled. Theory and modeling are indispensable in this context. We will present a hierarchical framework that self-consistently couples the impacts of the microkinetics, mass transport and double layer charging effects (going beyond Frumkin corrections).1,2 In our modelling work, we will assess the role of distinct phenomena and parameters at play in a step-by-step fashion. The developed framework will be demonstrated for the FAOR and other electrocatalytic reactions.

Molecular Additives at the Catalyst Ionomer Interface

The growth and viability of deep decarbonization through the hydrogen economy is dependent upon scientific advances that will address the existing political, regulatory, and technological barriers that currently hinder electrochemical energy technologies. The strong correlation between device-level performance and catalytic electrode activity/durability highlights the criticality of identifying the limiting processes and developing strategies to address these limitations. The goal of our group is to use fundamental insight derived from the study of well-defined systems to develop unique mitigation strategies, aimed at improving device-level performance, that go beyond simply varying electrocatalyst material properties. The interface between catalyst and ionomer in polymer electrolyte membrane fuel cells (PEMFC) greatly limits device performance through detrimental impacts to local reactant transport and reaction kinetics. Optimization of the catalyst/ionomer interface to not only mitigate these detrimental impacts, but to also beyond existing performance is a challenging task. In this presentation we will present our work in developing molecular interfacial modifying species to optimize the interaction between catalyst and ionomer. Integrating molecular components such as ionic liquids or caffeine both enhances the kinetics of the electrode reactions and limits the detrimental impacts of ionomer on the catalyst surface. We will present our fundamental understanding of why these molecular additives improve catalyst activity and limit the impacts of ionomer. We will also present our integration of these molecular moieties into next generation ionomers and their performance in PEMFC membrane electrode assemblies (MEA).

Stabilizing Ca-ion batteries with a 7000-cycle lifespan and superior rate capability by a superlattice-like vanadium heterostructure

Calcium-ion batteries (CIBs) by their strong competitiveness in cost and capacities have been considered as a desirable electrochemical energy technology. Nonetheless, the large ion radius and high charge density of Ca2+ lead to sluggish electrochemical reaction kinetics and structural collapse of electrode materials. Herein, we construct a superlattice-like poly 3,4-ethylenedioxythiophene−V2O5 (P–V2O5) heterostructure using an in situ self-assembly strategy and employ it as a CIB cathode. In the heterostructure, the inserted poly 3,4-ethylenedioxythiophene enlarges the interlayer of V2O5, exposing abundant active sites for efficient Ca2+ absorption and transport; meanwhile, it serves as an ‘interlayer linker’ between neighboring layers, which alleviates the volume change of V2O5 during Ca2+ insertion/extraction processes. Under the synergistic effect of these factors, the P–V2O5 electrode exhibits a longer life span and greater rate capability than pristine V2O5. Specifically, the electrode delivers a significant capacity of 157.2 mAh/g at 1 A/g and excellent cycle stability over a long period of 7000 cycles at a high current density of 20 A/g. Furthermore, it has a superior rate capability of 129.0 mAh/g even at 30 A/g. Electrochemical mechanism studies reveal that the insertion/extraction of Ca2+ in P–V2O5 is highly reversible, accompanied by the interlayer contraction/expansion.

Electrolyte design for lithium-ion batteries with a cobalt-free cathode and silicon oxide anode

Lithium-ion batteries (LIBs) to power electric vehicles play an increasingly important role in the transition to a carbon neutral transportation system. However, at present the chemistry of LIBs requires, among other elements, cobalt (Co), which will probably become scarce over time in addition to posing supply chain risks related to its single source, human rights and mining practices. To address this problem, we construct a LIB pairing a Co-free cathode with a silicon suboxide (SiOx) anode that possesses a high cut-off voltage of 4.9 V and sustains unprecedented 1,000 cycles. Underlying this favourable electrode combination is a rational electrolyte design based on 3.4 M LiFSI/FEMC featuring a shifted potential, which serves to aid formation of robust passivation layers on the anode and promote electrolyte stability against both reductive and oxidative degradations. Our electrolyte formulation offers a pathway towards both sustainable and high-performing LIBs, while the concept could be applied to other electrochemical energy technologies.

A Novel Adaptive Neural Network-Based Thermoelectric Parameter Prediction Method for Enhancing Solid Oxide Fuel Cell System Efficiency

Efficiency prediction plays a crucial role in the ongoing development of electrochemical energy technology. Our industries heavily depend on a reliable energy supply for power and electricity, and solid oxide fuel cell (SOFC) systems stand out as renewable devices with immense potential. SOFCs, as one of the various types of fuel cells, are renowned for their capability of combined heat and power generation. They can achieve an efficiency of up to 90% in operation. Furthermore, due to the fact that water is the byproduct of their electricity generation process, they are extremely environmentally friendly, contributing significantly to humanity’s sustainable development. With the advancement of renewable energy technologies and the increasing emphasis on sustainable development requirements, predicting and optimizing the efficiency of SOFC systems is gaining importance. This study leverages data collected from an SOFC system and applies an improved neural network structure, specifically the dendritic network (DN) architecture, to forecast thermoelectric efficiency. The key advantage of this method lies in the adaptive neural network algorithm based on the dendritic network structure without manually setting hidden nodes. Moreover, the predicted model of thermoelectric efficiency is validated using 682 and 1099 h of operational data from the SOFC system, and the results are compared against a conventional machine learning method. After comparison, it is found that when the novel method with adaptive characteristics proposed was used for SOFC system efficiency prediction, the MAE and RMSE values were both lower than 0.014; the result is significantly better than from other traditional methods. Additionally, this study demonstrated its effectiveness in predicting the thermoelectric efficiency of SOFC systems through secondary experiments. This study offers guidance on enhancing SOFC systems thermoelectric efficiency. Therefore, this study provides a foundation for the future industrialization of fuel cell systems.

Electrochemical Science & Engineering Graduate Program at the University of California Irvine

The initiative to create an interdisciplinary program to train PhD (and in parallel terminal ME) graduate students in electrochemistry have been in circulation at University of California Irvine (UCI) since the Fall of 2018. Several “grass-root” meetings of faculty with sustained professional interests in the general interdisciplinary area of electrochemistry and electrochemical engineering involving faculty from UCI School of Physical Sciences (Chemistry and Physics & Astronomy) and Henry Samueli School of Engineering (Chemical & Biomolecular Engineering, Materials Science & Engineering, Mechanical & Aerospace Engineering) have taken place and lead to an internal formal proposal to create the program. This process was additionally catalyzed by the transformation of UCI Advanced Power & Energy Program into UCI Clean Energy Institute, to include National Fuel Cell Research Center and Horiba Institute for Mobility & Connectivity. This initiative was indeed halted for practically three years by the COVID pandemics and is being revisited just now in the Fall of 2022. The campus wide initiative Electrochemical Science & Engineering aims to support building a strong academic discipline to serve as a science and engineering backbone for decarbonization of technology and economy. The general research areas are (listed below) are being supported by a series of graduate classes: Electrochemistry & Electroanalytical Methods (Chemistry); Electrochemical Thermodynamics & ElectrochemicalSystems (MAE); Kinetics of Electrochemical Processes (CBE); Electrochemical Engineering (CBE); Electrochemical Energy Conversion & Storage (CBE) and Solid-State Electrochemistry (MSE) – all of which have been taught in a given, pre-arranged sequence as electives in correspondent departments with an substantially overlapping student audience during 2020/21 and 2021/2022 Academic Years. New technical electives in the areas of Bioelectrochemistry & Bioenergetics, Electrochemical Sensors & Biosensors and Electrochemical Water Treatment Technologies are being prepared for the 2022/223 Academic Year by newly recruited faculty. The lineup of the curriculum and the segmentation of it into specializations will be discussed. We will also address the creation of professional (termina) Master in Engineering (ME) graduate program.Research themes that will be covered by the program are practiced by some 17 faculty at UC: Electrochemical energy technologies, such as fuel cells, electrochemical sensors, electrolyzes, and batteries, use chemical change to produce electricity, or vice versa, and consist of catalytic electrodes and ion-conducting electrolytes. Ion transport between the electrolytes is often limited due to intrinsic properties of (often polymeric) ion-exchange membranes, or low-temperature conductivity of solid-state ionic materials. The next frontier in the science and technology of electrochemical interfacesis exploiting the unique opportunities offered by our emerging ability understand ionic and charge transfer interactions at nanoscale and to tailor both soft and solid-state materials structures to facilitate such interactions including in corrugated and confined structures. Electrocatalytic systems directly utilize electrical energy to perform redox reactions. The latter is essential to most chemical bond forming/breaking events and in energy storage and utilization reactions. Molecular electrocatalysis effort is focused on designing molecules with tailored active sites, predicted by computational chemistry, in order to achieve optimal energies in abundant metals. This further extends to bioelectrocatalysis by proteins and bioelectrochemistry of cells.

Measuring Electrochemical Potentials for Health Monitoring of Redox Flow Batteries

Long-duration energy-storage (LDES) systems have the potential to transform the electric grid. Redox Flow Batteries (RFBs) have many unique attributes that make this battery architecture ideally suited for grid-scale LDES, namely: independent power and energy; long cycle life, even with deep cycles; inherently superior safety [1]; and easy recyclability. However, despite a recent renaissance in RFB technologies, assessing the durability of RFB cells is a topic that has not received much attention in the open literature, and further research is needed to better understand the performance and degradation mechanisms [2]. In-situ health monitoring of RFBs is critical for maximizing their lifetime and efficiency. Measurements of the electrochemical potentials of the electrodes and the electrolyte can provide insights into whether operating parameters are being adhered to and can potentially detect failure mechanisms occurring real-time within the battery. Since the electrochemical potential of both the positive and negative electrolytes exhibits Nernstian behavior, they are convertible to state-of-charge (SOC) measurements. Ensuring that the electrolyte stays within a desired SOC window during operation is essential for the mitigation of undesirable side reactions, such as the hydrogen-evolution reaction (HER) [3]. In addition, measurements of the potential difference between the electrode and the electrolyte, commonly known as overpotential, during charging and discharging processes allow for independent quantification of the reaction efficiency at each electrode. Factors affecting this reaction efficiency may include reaction kinetics, the mass transport of active species to the electrodes, the plating of impurities onto the electrode surface, and the mobility of ions across the ion-exchange membrane. Analysis of overpotential can also be useful in detecting failure mechanisms relating to these various factors [4]. Largo Clean Energy has developed multiple methods to measure electrochemical potentials in all-vanadium RFBs (VRFBs). The focus of this talk will be on how one can use these different measurements to assess the performance of VRFB cells. References R. Wittman, M. L. Perry, T. N. Lambert, B. R. Chalamala, and Y. Preger, “Perspective – On the Need for Reliability and Safety of Grid-Scale Aqueous Batteries,” J. Electrochemical Society, 167 (2020).Y. Yao, J. Lei; Y. Shi; F. Ai; T. C. Lu, “Assessment methods and performance metrics for redox flow batteries,” Nature Energy, 6 (2021).C. Tai-Chieh Wan, K. E. Rodby, M. L. Perry, Y.-M. Chiang, F. R. Brushett, “Hydrogen evolution mitigation in iron-chromium redox flow batteries via electrochemical purification of the electrolyte,” J. of Power Sources, 554 (2023).M. L. Perry and R. M. Darling, “Development of a Simple and Rapid Diagnostic for Redox Flow-Battery Cells,” Symposium I02: Frontiers of Chemical/Molecular Engineering in Electrochemical Energy Technologies, 242nd ECS Meeting, (2022).

Engineering cobalt-pyridinic N moieties on hybrid interfaces for alkaline hydrogen evolution

Efficient establishment of transition-metal electrocatalysts is critical for the advancement of clean energy. Herein, we utilize laser ablation to controllably fabricate plenty of cobalt (Co)-pyridinic nitrogen (N) moieties on the hybrid interface between CoO and N-modified graphene with mesoporous-rich architectures. This approach results in a tri-functional catalyst with excellent performance in three crucial electrocatalytic reactions, i.e., hydrogen and oxygen evolution (HER and OER), and oxygen reduction (ORR). More importantly, subsequent control experiments highlight the essential role of Co-pyridinic N bonds in boosting HER. As we previously reported, the catalyst exhibited exceptional performance for oxygen-related catalysis (ORR/OER) in 1.0 M KOH. In this study, it only requires a low exterior voltage of 1.64 V to fulfill the current density of 10 mA cm−2 for driving overall water splitting in the same electrolyte. The Co-pyridinic N moieties present in the catalyst are credited for the superior performance, as they can facilitate the protons adsorption with a decreased Gibbs free energy, and also serve as reaction centers for promoting water dissociation. This study will pave a new avenue for the installation of highly sought-after electrochemical energy technologies.

ACS Sustainable Chemistry & Engineering Virtual Special Issue on Sustainable Electrochemical Energy Technologies (Héctor D. Abruña Festschrift)

ADVERTISEMENT RETURN TO ARTICLES ASAPPREVEditorialNEXTACS Sustainable Chemistry & Engineering Virtual Special Issue on Sustainable Electrochemical Energy Technologies (Héctor D. Abruña Festschrift)Shaowei ChenShaowei ChenUniversity of California Santa Cruz, Santa Cruz, California, United StatesMore by Shaowei Chenhttps://orcid.org/0000-0002-3668-8551, Lin ZhuangLin ZhuangWuhan University, Wuhan, ChinaMore by Lin Zhuanghttps://orcid.org/0000-0002-5642-6735, and Enrique HerreroEnrique HerreroUniversidad de Alicante, Alicante, SpainMore by Enrique Herrerohttps://orcid.org/0000-0002-4509-9716Cite this: ACS Sustainable Chem. Eng. 2023, XXXX, XXX, XXX-XXXPublication Date (Web):May 22, 2023Publication History Received17 May 2023Published online22 May 2023https://doi.org/10.1021/acssuschemeng.3c02942Published 2023 by American Chemical SocietyRIGHTS & PERMISSIONSArticle Views-Altmetric-Citations-LEARN ABOUT THESE METRICSArticle Views are the COUNTER-compliant sum of full text article downloads since November 2008 (both PDF and HTML) across all institutions and individuals. These metrics are regularly updated to reflect usage leading up to the last few days.Citations are the number of other articles citing this article, calculated by Crossref and updated daily. Find more information about Crossref citation counts.The Altmetric Attention Score is a quantitative measure of the attention that a research article has received online. Clicking on the donut icon will load a page at altmetric.com with additional details about the score and the social media presence for the given article. Find more information on the Altmetric Attention Score and how the score is calculated. Share Add toView InAdd Full Text with ReferenceAdd Description ExportRISCitationCitation and abstractCitation and referencesMore Options Share onFacebookTwitterWechatLinked InReddit PDF (644 KB) Get e-AlertsSUBJECTS:Catalysts,Electrodes,Hydrogen,Oxides,Redox reactions Get e-Alerts