Electrochemical Engineering Research Articles

Novel ZIFs nanostructures electro-engineered at carbon fiber for the highly sensitive and selective detection of isoeugenol.

Novel zeolitic imidazolate frameworks (ZIFs), classical subtypes of metal organic frameworks (MOFs), and nanostructures are electro-engineered onto carbon fiber (CF), leading to a unique freestanding electrochemical platform of budlike nano Zn-ZIFs decorated CF (BN-Zn-ZIFs/CF). The unique morphology, structure, and composition are characterized by electron microscopy and energy spectrum analysis. Notably, the BN-Zn-ZIFs/CF platform displays superb electrocatalysis towards the oxidation of isoeugenol with encouragingly low overpotential and high current response. The strong electrocatalytic oxidation capability of BN-Zn-ZIFs/CF makes it an excellent sensing platform for isoeugenol detection. BN-Zn-ZIFs/CF sensor exhibits high-performance isoeugenol sensing with an extremely low limit of detection (13nM) and wide detection range (0.1-700µM). Besides, the BN-Zn-ZIFs/CF sensor can greatly resist interference from common ions, major biomolecules, and some amino acids. Moreover, excellent reliability, stability, and practicality are obtained. Our work demonstrates that the as-prepared BN-Zn-ZIFs/CF can act as an high-performance electrochemical sensor for the isoeugenol detection, the well-developed ZIF nanocrystal-modified conductive substrates can be a unique platform for the efficient sensing of other molecules, and the electrochemical engineering strategy can be an effective method for the growing of fresh MOF nanocrystals at conductive substrates in various electrochemical applications.

Electrochemical engineering of ZIF-7 electrode using ion beam technology for better supercapacitor performance

In the study, ZIF-7 material was exposed to 500 keV copper (Cu++) ions at dosages of 1 × 1014, 1 × 1015, and 5 × 1014 ions/cm2. The ZIF-7 unirradiated reveals a polycrystalline with an intense peak at 16.231° with a crystal plane of (012). The intensity of the peak in the XRD pattern broadens as the radiation of copper ions increases. In the ZIF-7 FTIR, the CC stretching vibration of the benzene ring is visible at 1469 cm−1, and the hydroxy phenyl benzimidazole (bIm) ligand's CH bending vibration is visible at 740 cm−1. Irradiated ZIF-7 reveals CH bending at 758, 759, and 754 cm−1 from the bIm ligand and CC stretching at 1456, 1460, and 1457 cm−1. The CV plots showed redox peaks, demonstrating faradaic processes. The ZIF-7's unirradiated estimated specific capacitances at scan rates of 50, 40, 30, 20, and 10 mV/s are 156, 195, 260, 390, and 781 F/g. The estimated specific capacitance of the irradiated ZIF-7 material with copper ions of 1 × 1014 ions/cm2 is 185, 308, 462, and 925 F/g. The estimated specific capacitance for ZIF-7 with copper ions of 1 × 1015 and 5 × 1014 ions/cm2 are 187, 234, 468, 937, and 1200 F/g, and 300, 375, 500, 750, and 1200 F/g respectively. The unirradiated (ZIF-7) shows bandgap energy of 3.53 eV which is suitable for applications in gas separation, catalysis, and optoelectronics. The irradiated sample with 1 × 1014 ions/cm2, 1 × 1015 ions/cm2 and 5 × 1014 ions/cm2 revealed bandgap energy of 2.52 to 2.87 eV which is suitable energy storage application.

In Situ Probing the Structure Change and Interaction of Interfacial Water and Hydroxyl Intermediates on Ni(OH)2 Surface over Water Splitting.

There is growing acknowledgment that the properties of the electrochemical interfaces play an increasingly pivotal role in improving the performance of the hydrogen evolution reaction (HER). Here, we present, for the first time, direct dynamic spectral evidence illustrating the impact of the interaction between interfacial water molecules and adsorbed hydroxyl species (OHad) on the HER properties of Ni(OH)2 using Au/core-Ni(OH)2/shell nanoparticle-enhanced Raman spectroscopy. Notably, our findings highlight that the interaction between OHad and interfacial water molecules promotes the formation of weakly hydrogen-bonded water, fostering an environment conducive to improving the HER performance. Furthermore, the participation of OHad in the reaction is substantiated by the observed deprotonation step of Au@2 nm Ni(OH)2 during the HER process. This phenomenon is corroborated by the phase transition of Ni(OH)2 to NiO, as verified through Raman and X-ray photoelectron spectroscopy. The significant redshift in the OH-stretching frequency of water molecules during the phase transition confirms that surface OHad disrupts the hydrogen-bond network of interfacial water molecules. Through manipulation of the shell thickness of Au@Ni(OH)2, we additionally validate the interaction between OHad and interfacial water molecules. In summary, our insights emphasize the potential of electrochemical interfacial engineering as a potent approach to enhance electrocatalytic performance.

Improved Operation of Chloralkaline Reversible Cells with Mixed Metal Oxide Electrodes Made Using Microwaves.

This study focuses on the synthesis of mixed metal oxide anodes (MMOs) with the composition Ti/RuO2Sb2O4Ptx (where x = 0, 5, 10 mol) using hybrid microwave irradiation heating. The synthesized electrodes were characterized using scanning electron microscopy, X-ray energy-dispersive analysis, X-ray diffraction, cyclic voltammetry, and electrochemical impedance spectroscopy. These electrodes were then evaluated in both bulk electrolytic and fuel cell tests within a reversible chloralkaline electrochemical cell. The configurations using the electrodes Ti/(RuO2)0.7-(Sb2O4)0.3 and Ti/(RuO2)66.5-(Sb2O4)28.5-Pt5 presented lower onset potential for oxygen and chlorine evolution reactions and reduced resistance to charge transfer compared to the Ti/(RuO2)63-(Sb2O4)27-Pt10 variant. These electrodes demonstrated notable performance in reversible electrochemical cells, achieving Coulombic efficiencies of up to 60% when operating in the electrolytic mode at current densities of 150 mA cm-2. They also reached maximum power densities of 1.2 mW cm-2 in the fuel cell. In both scenarios, the presence of platinum in the MMO coating positively influenced the process. Furthermore, a significant challenge encountered was crossover through the membranes, primarily associated with gaseous Cl2. This study advances our understanding of reversible electrochemical cells and presents possibilities for further exploration and refinement. It demonstrated that the synergy of innovative electrode synthesis strategies and electrochemical engineering can lead to promising and sustainable technologies for energy conversion.

Power Generation Limits in Thermal, Chemical and Electrochemical Systems

Power generation limits are evaluated via optimization for various energy converters, such like thermal, solar, chemical, and electrochemical engines, in particular fuel cells. Thermodynamic analyses lead to converters’ efficiencies, which help to solve problems of optimal upgrading and downgrading of resources. While methods of static optimization, i.e. differential calculus and Lagrange multipliers, are sufficient for steady processes, dynamic optimization applies the variational calculus and dynamic programming for unsteady processes. In reacting systems chemical affinities constitute prevailing components of an overall efficiency, thus flux balances are applied to derive power in terms of active parts of chemical affinities. Methodological similarity is observed when treating power limits in flow thermal machines and fuel cells. The examples show power maxima in fuel cells and prove suitability of a thermal machine theory to chemical and electrochemical systems. The main novelty of contribution in the fuel cell context consists in introducing an effective change of Gibbs free energy between products p and reactants s which takes into account lowering of voltage and power caused by the incomplete conversion of the overall electrochemical reaction.

Recent advances in upgrading CO2 to C3+ products via electrochemical and complementary engineering

This review summarizes the latest advances in material development and process design for electrochemically upgrading CO2 to value-added C3+ chemicals.

Characterization of Nanostructured Tin Oxide Anodes Obtained By Electrolytic Oxidation for High-Energy Lithium-Ion Batteries

In recent years, the growing electric vehicle market has increased the need for cost efficient and high energy materials for batteries drastically. Tin and tin oxide materials bear great potential as anode materials for Li-Ion batteries due to low cost and high theoretical capacity. Nevertheless, the development of commercial tin anodes has so far been hindered due to several drawbacks related to high volume expansion during operation leading to fast cell degradation. To circumvent these issues, nanostructured electrodes can be applied to mitigate volume changes. Typically, the production process of such electrodes is challenging, leading to high cost and issues in terms of scalability. Electrochemical processes, such as the electrolytic oxidation of tin, has been found a promising alternative to fabricate nanostructured electrodes. The additive-free tin oxide anodes obtained from this process exhibit high gravimetric and volumetric capacity, excellent rate capability as well as promising cycle life. The morphology and microstructure have high impact on the rate capability and cycling stability of tin oxide anodes. Since structural properties can be precisely adjusted by controlling the electrochemical oxidation process, a deeper understanding of the structure-property relationship is needed to optimize the production process and pave the way for commercialization.Herein an in-depth characterization of nanostructured tin oxide anodes formed by electrochemical oxidation is presented. The rate capability and the cycling stability are investigated by means of electrochemical measurements in battery cells. Operando electrochemical dilatometry is used to investigate the thickness change of the anodes during cycling (cell breathing). In-situ XRD measurements are applied to elucidate the reaction mechanism. The anodes are carefully analyzed by SEM/EDS at different state of lithiation to understand the impact of volume changes on the inner porosity and morphology. Finally, the cycling stability of tin oxide anodes is improved by applying an electrochemical prelithiation step. Therefore, the impact of different prelithiation regimes on the cycling stability is evaluated in full cells. The results contribute to the understanding of electrochemical behavior of nanostructured tin oxide anodes and the derivation of optimal design criteria adjusted by electrochemical surface engineering.

Surface Finishing or Shaping By Pulse/Pulse-Reverse Electrolysis

Faraday Technology Inc. is a research, development and electrochemical engineering firm developing electrochemical innovations based has pulse/pulse reverse electrolytic principles. [1,2] With that founding basis Faraday has been able to bridge the gap between academic understanding and small-scale demonstrations to commercialization of practical components for over 32 years of operation. This presentation will discuss a broad range of surface finishing studies including a wide range of metals, additively manufactured parts, electrochemical machining, and highly complex structures. We will highlight some of the key factors that determine the usefulness and successfulness of using pulse/pulse reverse principles to enable simple water-based HF free electrolytes to finish or shape a wide range of metal surfaces. For instances, we will discuss electropolishing of Nb superconducting cavities, additively manufactured grade 5 Ti impellers, and electrochemical machining to create complex impossible to machine shapes. Each process utilizes pulse/pulse reverse operations to overcome key challenges with boundary layer control, oxidation/reduction of the surface, and the uniformity of the finish.

(Invited) Case Studies for in-Space Electrochemical Operations

Faraday Technology Inc. is a research, development and electrochemical engineering firm developing electrochemical innovations for terrestrial and space system.[1,2] With that founding basis Faraday has been able to bridge the gap between academic understanding and small-scale demonstrations to commercialization of practical components for over 32 years of operation.This presentation will discuss a broad range of electrochemical approaches to improve the performance of components used in space or to be used for in-space production. We will provide insight into case studies, performed at Faraday, from our four business units of electrodeposition, electrochemical surface finishing, electrochemical conversion, and electrochemical system design. For instances, we will discuss direct print electrodeposition, electrophoretic application of coatings for glare resistance, surface finishing of rocket components, bioelectrochemical treatment of urine, and the generation of peroxide. Each electrochemical process has applications on earth and in space; additionally, each program had to overcome specific challenges that only space can present.

Quantifying Volume Change in Porous Electrodes Via the Multi-Species, Multi-Reaction Model

Automotive manufacturers are working to improve individual cell and overall pack design by increasing their performance, durability, and range, while reducing cost; and active material volume change is one of the more complex aspects that needs to be considered during this process. As the time from initial design to manufacture of electric vehicles is decreased, design work that used to rely solely on testing needs to be supplemented or replaced by virtual methods. As electrochemical engineers drive battery and system design using model-based methods, the need for coupled electrochemical/mechanical models that take into account the active material change utilizing physics based or semi-empirical approaches is necessary[1-8]. In this study, we illustrated the applicability of a mechano-electrochemical coupled modeling method considering the multi-species, multi-reaction model as popularized by Verbrugge[9-14] and Baker. To do this, validation tests were conducted using a computer-controlled press apparatus that can control the press displacement and press force with precision. The coupled MSMR volume change model was developed and its applicability to graphite and NMC cells was illustrated. The increased accuracy of the model considering the coupled MSMR volume change approach shows in the importance of accounting for individual gallery volume change behavior on cell level predictions. References T. R. Garrick, K. Kanneganti, X. Huang and J. W. Weidner, J Electrochem Soc, 161, E3297 (2014).T. R. Garrick, Y. Dai, K. Higa, V. Srinivasan and J. W. Weidner, Ecs Transactions, 72, 11 (2016).T. R. Garrick, K. Higa, S.-L. Wu, Y. Dai, X. Huang, V. Srinivasan and J. W. Weidner, J Electrochem Soc, 164, E3592 (2017).T. R. Garrick, X. Huang, V. Srinivasan and J. W. Weidner, J Electrochem Soc, 164, E3552 (2017).D. J. Pereira, J. W. Weidner and T. R. Garrick, J Electrochem Soc, 166, A1251 (2019).D. J. Pereira, M. A. Fernandez, K. C. Streng, X. X. Hou, X. Gao, J. W. Weidner and T. R. Garrick, J Electrochem Soc, 167, 080515 (2020).T. R. Garrick, J. Gao, X. Yang and B. Koch, J. Electrochem. Soc. (2021).D. J. Pereira, A. M. Aleman, J. W. Weidner and T. R. Garrick, J Electrochem Soc, 169, 020577 (2022).M. Verbrugge, D. Baker and X. Xiao, J Electrochem Soc, 163, A262 (2016).M. Verbrugge, D. Baker, B. Koch, X. Xiao and W. Gu, J Electrochem Soc, 164, E3243 (2017).D. R. Baker and M. W. Verbrugge, J Electrochem Soc, 165, A3952 (2018).D. R. Baker and M. W. Verbrugge, J Electrochem Soc, 167, 013504 (2019).D. R. Baker, M. W. Verbrugge and W. Gu, J Electrochem Soc, 166, A521 (2019).M. W. Verbrugge, X. Xiao and D. R. Baker, J Electrochem Soc, 167, 080523 (2020).

(Invited) Industrial Relevance of Pulsed Electrochemical Methods

Industrial demands are the driving force on any optimization and development process for electrochemical plating processes and coatings. The classical demands focused on the mechanical properties such as wear resistance and hardness as well as the stability against corrosion.The galvanic coatings were tailored for meeting these requirements, defining the electrochemical systems that are currently standard in galvanic protection of industrial parts.With the introduction of new applications and production methods over the last 10 to 15 years additional functionality has been seeked by the industry, including chemical stability, bio-compatibility, microstructured surfaces, lubrication effects, magnetic properties and the ability of shock absorbance. Coating had to be adjusted, leading to the industrial realisation of dispersion and compound coatings, alloy deposition on a wider scale and Pulse (reverse) plating. While these, from an industrial perspective, relatively new plating processes already required some major rethinking of the traditional galvanic industry, the industrial requirements got even more demanding over the last few years. Especially with the origin of new industrial production methods, the homogenous treatment and coating of e.g. complex bionical structures became relevant.In order to follow the changing demands, the transfer from the classical thermodynamically controlled direct current or constant potential based surface treatment towards a kinetically controlled pulsed surface finishing has to be executed.While pulse plating is the most popular representation of these categories of finishing processes, pulsed electrochemical processes comprise a much larger variety of methods. Among these, pulse anodization, pulsed plasma electrolytic oxidation (PEO), pulsed electropolishing, electrochemical machining (ECM) and the recently introduced Hirtisation process are industrially used.The presenation will give an overview of possibilities for electrochemical engineering of surfaces for high-end technical applications by pulsed electrochemical techniques.

Coating Applications By Pulse/Pulse Reverse Electrolysis

Faraday Technology Inc. is a research, development and electrochemical engineering firm developing electrochemical innovations based has pulse/pulse reverse electrolytic principles. [1,2] With that founding basis Faraday has been able to bridge the gap between academic understanding and small-scale demonstrations to commercialization of practical components for over 32 years of operation.This presentation will discuss a broad range of electrodeposition studies including single metal, alloy, composite and electrophoretic. We will highlight some of the key factors that determine the usefulness and successfulness of using pulse/pulse reverse principles to apply materials to a broad range of structures. For instances, we will discuss additive free Cu deposition into a microvia, functionally graded NiMo coatings from a single electrolyte, graphene incorporation into a Cu film, and electrophoretic deposition of CNTs. Each process utilized pulse/pulse reverse plating to overcome key challenges with diffusion, stress, composition, adhesion, and functional properties.

Process Intensification of Electrodialysis through the Investigation and Elimination of Maldistribution

Often, advancements in electrochemical engineering processes stem from improvements at the microscale and in fundamental understanding. However, there is often much insight to be gained from identifying engineering challenges associated with process operation. Electrodialysis (ED) is an emerging electro separation technology which utilises a stack of ion selective membranes and an electric field to drive salt transfer between streams. Industrial implementation and intensification of ED is currently hindered by operational efficiencies being far from ideal. In this work, we explore a system-wide approach to investigate operational inefficiencies resulting from maldistribution in the flow between ED channels.Through computational fluid dynamics (CFD) simulations, it was shown that maldistribution is prevalent in ED. Further, a simplified analytical model demonstrated that the degree of maldistribution will be far more severe upon scale-up. In order to examine the effects of maldistribution on ED performance, transport models were built. These demonstrated that the limiting current density, and thus the maximum salt flux, was reduced by as much as 23% for a standard lab-scale stack. This will be much more significant upon scaleup, and therefore, overcoming maldistribution in ED can have significant benefits for process intensification. Validation of this was conducted through particle image velocimetry (PIV) and desalination experiments.A glass cell was constructed for PIV experiments with an identical geometry to that used for CFD simulations. A camera and telecentric lens was focussed on the channel centreline, and red and blue LEDs were sequentially pulsed. This light was scattered off particles in water flowing through the cell and collected by a single exposure image. The particle velocities were calculated from the superimposed red and blue images and a flow field was constructed. The experimentally determined flow field had excellent agreement with that found from CFD simulations, validating the existence of maldistribution in ED.Desalination experiments were conducted on a PC64004 ED stack operating in a steady state mode. The degree of maldistribution was independently altered by changing the flow rate while ensuring that the overall salt convective flux was constant. The LCD was subsequently measured by collecting current-voltage curves. results showed excellent consistency with the transport model, thereby validating the relationship between increased maldistribution and a lower LCD.In summary, in this work we have demonstrated and validated the presence of maldistribution in ED, as well as the significant detrimental effect it has on the upper limits of process intensification. Further, we have demonstrated the benefits of investigating system-wide inefficiencies in addition to fundamental phenomena. Future research will focus on developing methods to overcome maldistribution in ED. Figure 1

Pulse/Pulse Reverse Electrolysis for Electrochemical Conversion Technologies

Faraday Technology Inc. is a research, development and electrochemical engineering firm developing electrochemical innovations based has pulse/pulse reverse electrolytic principles. [1,2] With that founding basis Faraday has been able to bridge the gap between academic understanding and small-scale demonstrations to commercialization of practical components for over 32 years of operation.This presentation will discuss techniques where pulse/pulse reverse operation enabled improved production rates, reduced energy demand, eliminated biofouling, and enabled recycling of complex structures. We will highlight some of the key factors that determine the usefulness and successfulness of using pulse/pulse reverse principles to improve process control of the electrochemical operations. For instances, we will discuss electrochemical destruction of PFAS, electrocatalytic operations, and carbon fiber recovery from composites.

Thermodynamic Analysis of Coal Derived Graphite for Battery Anodes Using the Multi-Species, Multi-Reaction Model

Automotive manufacturers are working to improve individual cell and overall pack design by increasing their performance, durability, and range, while reducing cost. As the time from initial design to manufacture of electric vehicles is decrease, design work that used to rely solely on testing needs to be supplemented or replaced by virtual methods. As electrochemical engineers drive battery and system design using model-based methods, models that have a basis in physics, rather than purely empirical representations, are necessary to allow engineers to drive design through a linkage to manufacturing methods. In this study, we apply the Multi-Species, Multi-Reaction model as popularized by Verbrugge and Baker to an electrochemical system comprised of a counter electrode and a working electrode synthesized from graphite derived from coal.To do this, the open circuit voltage of the coal derived graphite and a standard commercially available graphite was quantified. Linear sweep voltammetry provided insight into the shift in electrochemical reactions based on the structure and composition of the coal derived graphite. This then allows the MSMR model to capture the thermodynamic performance of the coal derived graphite, and sheds further insight into the performance compared to the standard commercially available system. Commentary on the thermodynamic differences between the systems will be provided and additional analytical techniques may be used to rationalize differences in performance.

Electrochemical surface functionalization engineering of carbon cloth for ultrasensitive electrochemical detection of nitrite

In this work, the commercial carbon cloth modified with a large number of oxygen-containing functional groups (C-OH, COOH and CO) was fabricated by simple constant current electrochemical treatment (EFCC electrode) for the ultrasensitive electrochemical detection of nitrite. Due to the combination of enhanced superhydrophilicity, significantly improved conductivity and dramatically increased active specific surface area and sites, the EFCC electrode exhibited excellent nitrite detection performance, including wide detection ranges of 0.1–3500 μM divided into three ranges, low detection limit of 0.016 μM (S/N = 3) and ultra-high sensitivities of 12310, 3515, 1877 μA mM−1 cm−2. This work provided an important reference for the application of functionalized modification strategies to construct high-performance electrochemical sensors.

Electrochemical heat engine based on neutralization flow battery for continuous low-grade heat harvesting

An enormous amount of energy is wasted annually in the form of low-grade heat with a temperature below 100 °C. Recently, studies on heat harvesting have focused on semiconductor-based devices, but nowadays, electrochemical devices based on a thermally regenerative cycle (TREC) are growing in importance due to their superior thermoelectric power. Among them, TRECs based on flow batteries (TREC-FB) are especially attractive since they offer more flexibility for heat harvesting and an opportunity for continuous heat-to-power (HTP) conversion. However, this technology struggles due to the high cost of the flow batteries they are based on, particularly the costly electrolyte solutions. We offer a novel approach for continuous heat harvesting based on the emerging technology of the neutralization flow battery (NFB) with low-cost and highly soluble electrolytes, which consists of two hydrogen electrodes immersed in acid and base solutions. Since values of both electrodes’ temperature coefficient differ, NFB can be used for heat harvesting: the cell temperature coefficient varies in the range of 0.64–1.1 mV K−1. Here, we present both intermittent and continuous TREC based on NFB, with a focus on the latter due to its convenience. Our study on continuous heat harvesting shows that for a temperature difference between the heat source and heat sink of 25 °C, one can achieve power of 10–24 μW cm−2, and efficiency of 1.4–2.9 % even without any recuperation. Alternatively, increasing the temperature difference to 55 °C results in a 6-fold increase in power at 1.6–3.5 % efficiency. We found that due to the low freezing point of the electrolytes, one can obtain even higher HTP performance if the heat sink temperature is about 0 °C. Additionally, we examined NFB performance under various temperatures and proposed low-grade heat harnessing using intermittent NFB heating/cooling to enhance its cycling performance. We believe that the proposed approaches facilitate further development of high-performance TREC-FB and thereby extend the possibilities for heat harvesting.

Electrochemical Reconstruction Engineering: Metal–Organic Gels as Pre‐Catalysts for NiOOH/FeOOH Heterostructure to Boost Oxygen Evolution Reaction

Electrochemical Reconstruction Engineering: Metal–Organic Gels as Pre‐Catalysts for NiOOH/FeOOH Heterostructure to Boost Oxygen Evolution Reaction

Hierarchical implementation of electrochemical techniques to provide a reliable diagnosis of commercial lithium-ion pouch cells under selected operational conditions

Understanding the performance of commercial Lithium-Ion batteries (LIBs) under various operational conditions is a paramount concern for ensuring their long-term stability. While numerous methodologies exist from a materials perspective to enhance comprehension of fundamental phenomena, electrochemical engineers often rely only on charge/discharge curves. Although these curves provide valuable insights, their information can be enriched through the systematic implementation of electrochemical protocols. This approach offers more nuanced data that can facilitate swift diagnostics of LIB conditions and enable in-depth analysis of underlying physicochemical processes. In this study, a comprehensive methodology is proposed for assessing the reversibility, stability, dominant processes, and degradation effects of LIBs. This involves combining charge/discharge curves with complementary electrochemical techniques and specific methodologies to extract maximum information from the data; for this purpose the following strategies are sequentially applied: Galvanostatic Cycling with Potential Limitation (GCPL), Galvanostatic Electrochemical Impedance Spectroscopy (GEIS), Distribution of Relaxation Time protocols (DRT), and Differential Capacitance (DC) analysis to a range of commercial pouch cell LIBs under diverse conditions. By correlating the results obtained through these techniques, we established meaningful interpretations of battery performance, thorough specialized protocols based on DRT and DC analysis, under various operational case scenarios, the effect of temperature, C-rate, and extended cycling. These protocols yielded crucial electrochemical parameters and relevant characteristics, enabling advanced diagnostics. The proposed framework serves as a guide for methodologically analyzing commercial batteries, it underscores that traditional characterization techniques can be augmented with additional analyses to comprehensively grasp the performance of commercial LIBs.

E-Chem Education: A Crash Course in Electrochemical Engineering for Caustic Soda Plant Design

The capstone chemical engineering senior process design course at Penn State in spring 2023 tasked students with designing a caustic soda process to partially meet the global demand for commoditized sodium hydroxide. This article disseminates our experience teaching senior chemical engineering students the core tenets of electrochemical engineering in a single class period for designing an electrolytic caustic soda process. In this E-Chem Education article, we relate key concepts found in chemical engineering (such as sizing up a reactor volume), which chemical engineering seniors are adept with, to electrochemical engineering principles (e.g., current density, voltage, and membrane electrode assembly area) for sizing up and costing out a chlor-alkali electrolyzer. Furthermore, we also discuss alternative electrolyzer designs outside the traditional chlor-alkali process, such as oxygen depolarized cathode (ODC) chlor-alkali and bipolar membrane electrodialysis (BPMED), for caustic soda production and the pros and cons of the alternative process designs.