bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Cu3-x Nix)Co2-Layered Double Hydroxide Nanosheets for Enhanced Electrocatalytic Activity Towards Overall Water Splitting
Authors: Kansal Sakshi , Anshu Satvik , Ravindran Rahul , Priya Surbhi , Chandra Amreesh 
Published: September 2023

The exploration of transition metal based electrocatalyst for overall water splitting is becoming important as hydrogen becomes integral part of energy landscape. Recently, a new class of compounds i.e. layered double-hydroxides (LDHs), also known as anionic clays, are have shown tremendous promise for use as electrocatalyst. The lamellar morphology of LDHs accommodates higher active sites, that contributes to the facile electron transfer and thus attracts a great deal of interest in catalysis application. Moreover, the high catalytic activity of LDHs are also linked to their facile anion exchange, specific electronic structures, and versatile chemical compositions.
Herein, we have developed a series of ternary layered double hydroxide (LDH) using pH-adjusted co-precipitation method with varying ratio of Cu, Ni and Co, which are used as an electrocatalyst for overall water splitting. (CuxNi1)Co1-LDHs (x = 0.5 1, 1.5, and 2 ) were systematically characterized using XRD, XPS, SEM, FTIR, TEM and BET techniques. The synergistic contributions from the electrocatalytically active metals and lamellar morphology of LDHs promotes water dissociation, facilitates faster release of H2-O2 gas bubbles, ameliorate electrolyte ion diffusion and improves electron transfer rate. It is further observed that the (CuxNi1)Co1-LDHs showed excellent electrocatalytic activity for both hydrogen evolution (HER) and oxygen evolution reaction (OER) with an overpotential of 147 and 218 mV for HER and OER, respectively at 10 mA cm-2. Tafel slope was found to be lowest for (Cu1Ni1)Co1-LDH. Further, the durability of the materials was also analysed by performing chronoamperometry for over 12 h. The overall water electrolytic cell using (Cu1Ni1)Co1-LDH as both electrodes can reach 50 mA cm−2 at 1.9V with outstanding durability.
Experimental Aging and Lifetime Prediction in Grid Applications for Large-Format Commercial Li-Ion Batteries
Authors: Gasper Paul , Saxon Aron , Shi Ying , Smith Kandler , Thakkar Foram 
Published: September 2023

Due to the growth of electric vehicle and stationary energy storage markets, the production and use of lithium-ion batteries has grown exponentially in recent years. For many of these applications, large-format lithium-ion batteries are being utilized, as large cells have less inactive material relative to their energy capacity and require fewer electrical connections to assemble into packs. The economics of these battery systems is highly dependent on cell lifetime, requiring accelerated aging tests to characterize cell degradation. However, testing of large-format lithium-ion batteries is time consuming and requires high current channels and large testing chambers, so not many reports on the lifetime of commercial, large-format lithium-ion batteries exist. Here, accelerated aging test data from four commercial large-format lithium-ion batteries is reported. These batteries span both NMC-Gr and LFP-Gr cell chemistries, are from a variety of manufacturers, have pouch and prismatic formats, and show a range of cell designs with varying power capabilities.
Accelerated aging test results are analyzed to examine both cell performance, in terms of efficiency and thermal response under load, as well as cell lifetime. Cell thermal response is characterized by measuring temperature during cycle aging, which is used to calculate a normalized thermal resistance value that may help estimate both cell cooling needs or to help extrapolate aging test results to different thermal environments. Cell lifetime is evaluated qualitatively, considering the average calendar and cycle life across a range of conditions, as well as quantitatively, using statistical modeling and machine-learning methods to identify predictive aging models from the accelerated aging data. These predictive aging models are then used to investigate cell sensitivities to stressors, such as cycling temperature, voltage window, and C-rate, as well as to predict cell lifetime in various stationary storage applications.
Results from this work show that cell lifetime and sensitivity to aging conditions varies substantially across the cell types, necessitating testing for each specific cell to make quantitative lifetime predictions. That being said, all commercial cells tested here are predicted to reach at least 10-year lifetimes for stationary storage applications. Based on the aging test results and modeling, some cells are expected to be relatively insensitive to temperature and use-case, making them suited for simple use cases with little or no thermal management and simple controls, while the lifetime of other cells could be extended to 20+ years if operated with thermal management and degradation-aware controls.

Figure 1
In-Situ Measurement of Charge Transfer at Cocatalyst/Semiconductor Interfaces in BiVO4 Particle Photocatalyst
Authors: Shen Meikun , Kaufman Aaron James , Boettcher Shannon W. 
Published: September 2023

Semiconductor photocatalyst particles are known to transform solar energy to useful chemicals such as H2 or methanol. However, the efficiency of semiconductor photocatalysts often suffers from the quick charge carrier recombination. However, there is no real physical reasons for semiconductors to display this low performance. Multiple strategies have been proposed and applied to modify the semiconductor particles and enhance their solar-to-hydrogen efficiencies. It is often assumed that in semiconductor particles with well-defined crystal facets, the photogenerated charge carriers undergo facet-dependent separation. Thus, a common strategy is to deposit a HER electrocatalyst on ‘electron-selective’ facets and an OER electrocatalyst on ‘hole-selective’ facets. Although this strategy have showed plausible results in previous literatures, a precise understanding of how charge-carrier-selective contacts between the deposited electrocatalyst and semiconductor particles emerge and how the semiconductor photocatalysts are rationally designed is still missing.
In this work, we used both ex-situ and in-situ conducting AFM experiments and a new ionomer/catalyst–semiconductor test structures to characterize the charge transfer between semiconductor and deposited electrocatalysts at individual nanoparticle scale. We showed that the presence of the water/electrolyte interface is critical to induce hole selectivity between the CoOx OER cocatalyst and the BiVO4 semiconductor light absorber. We demonstrated that the negative surface charge on the semiconductor is central to induce hole selectivity. The work also demonstrates a facile strategy to control local pH and introduce water using thin-film ionomers for conductive AFM measurements. These new insights can be broadly applied to the rational design of semiconductor photocatalysts for overall water-splitting systems to control charge-carrier selectivity and improve their performance.
(Invited) True Particle-Size Dependence of Photocatalytic Activity of Octahedral-Shaped Anatase Titania
Authors: Ohtani Bunsho , Takashima Mai 
Published: September 2023

Here, attempts to prepare octahedral-shaped anatase titanium(IV) oxide (titania) particles (OAPs) of uniform bulk structure (anatase with negligible non-crystalline components), surface structure (only exposing {101} facets) and particle size are reported as the first and sole example of a "pure" metal-oxide powder. The OAP samples were prepared by sonication-hydrothermal (HT) reaction of potassium-titanate nanowires through the process modified from the previous report [1]. Characterization of the samples by Rietveld analysis of XRD patterns (including non-crystalline phases using an internal standard) [2], reversed double-beam photoacoustic spectroscopy (RDB-PAS; a method measuring energy-resolved distribution of electron traps mainly located on the surface of metal-oxide and the other semiconducting samples) [3,4] and SEM observations revealed the homogeneousness of crystalline bulk, surface and particle size, respectively, to indicate the samples "pure". By controlling the preparation conditions, several OAP samples with different average size ranging of ca. 60–260 nm keeping the purity of the OAP shape. Roughly speaking, the particle-size distribution of those samples was the size of ca. 80% particles in the range of +20% of the average. Photocatalytic activities of those samples in (a) methanol dehydrogenation with in-situ deposited platinum to yield hydrogen, (b) oxidative decomposition of acetic acid under aerobic conditions to yield carbon dioxide and (c) oxygen evolution from deaerated aqueous silver sulfate were examined under ultraviolet-light (> 290 nm) irradiation to find that there seemed no particle-size dependence for the systems (a) hydrogen evolution and (b) carbon-dioxide evolution, while the activity in system (c) to liberate oxygen was almost linearly increased with the particle size [5]. These particle-size dependences of photocatalytic activity seem strange but could be "true" considering the purity of those samples, i.e., almost pure bulk crystal component exposing only anatase{101} facets. The previously reported particle-size dependence might be incorrectly derived due to the unknown effects by the other structural parameters.
[1] Molecules
19, 19573 (2014). [2] Catal. Today
313, 218 (2018). [3] Chem. Commun.
52, 12096 (2016). [4] Electrochim. Acta
264, 83 (2018). [5] To be submitted.
Molecular Structures and Electrochemical Activity of Oversaturated Electrolytes
Authors: Li Yuanchao , Abbey Joshua , Singh Nirala , Nguyen Trung Van 
Published: September 2023

In applications ranging from biochemistry to electrochemistry, the solvation structures and agglomeration forms of ions are a focus of basic scientific study. Prior research has found that the concentration level and preparation conditions of these ionic electrolytes can affect the hydrated structure (e.g., tetrahedral or octahedral) and aggregate framework (e.g., intermolecular connection like ion cluster or network, or intramolecular connection like dissociation or undissociation).1–3 Our recent studies on vanadium (IV) sulfate (VOSO4), a transition metal salt used in redox flow batteries, show that in addition to the electrochemically active ions that can readily convert to V2+, V3+, and V5+ oxidation state, inactive molecules with different solvation structures and agglomerates also form in the electrolyte, and some of the inactive molecules can be converted to active ions while others cannot. The order of the preparation, such as dissolving the metal salt in water first and then adding the acid or vice versa, seems to have an impact on the ratio of the active ions and inactive molecules in the electrolyte. Furthermore, the closer the vanadium salt concentration is to its solubility limit, the higher the fraction of the inactive non-convertible molecule is. Finally, the inactive molecules in these electrolytes can be converted to active molecules by heating the electrolyte to a higher temperature (e.g., >50oC) and then cooling it down to room temperature. Similar electrochemical behavior was also observed in oversaturated FeCl3 solution, indicating that the coexistence of electrochemically active and inactive species above the solubility may be common for transition metal salt solutions.
Oversaturated electrolyte solutions are unstable and have been of little interest because they have been deemed to have no applications. However, for applications where the oversaturation state is only needed within its duration of stability, they provide many benefits such as higher concentrations that could translate to higher current density or power output in power source applications and higher energy density in a long-duration energy storage applications. Our presentation will discuss the stabilities, electrochemical performances, and possible solvation structures of VOSO4 and FeCl3 solutions with different concentrations and preparation methods.

References

S. Kim, H. Kim, J.-H. Choi, and M. Cho, J Chem Phys, 141, 124510 (2014).

I. Persson, J Solution Chem, 47, 797–805 (2018).

D. L. Wertz and M. L. Steele, Inorg Chem, 19, 1652–1656 (1980).
Design and Characterization of Azobenzene Electrolytes for Aqueous Redox Flow Batteries
Authors: Singh Siddhant , Tami Jessica L. , Gruich Cameron , Oudeif Fairooz , Goldsmith Bryan R. , McNeil Anne Jennifer , Kwabi David G. 
Published: September 2023

Aqueous redox-flow batteries (RFBs) containing organic redox electrolytes are a promising technology for grid-scale renewable energy storage. Most electrolytes currently under consideration for these RFBs contain charge-storing molecules that are drawn from a narrow collection of molecular scaffolds, and undergo rapid decomposition, which results in high rates of capacity fade. To inform efforts at developing more stable aqueous RFB electrolytes, it is critical that the kinetics of charge carrier decomposition and its relationship to capacity fade are well understood.
In this work, we explore a relatively new class of redox-active organic molecules known as azobenzenes as potential charge carriers in aqueous RFBs. The electrochemical properties and cycling performance of a range of substituted azobenzenes are characterized using cyclic voltammetry, chronoamperometry, and constant current-constant voltage cycling. Decomposition products are identified using UV-vis and proton nuclear magnetic spectroscopy, as well as mass spectrometry. We discern the influence of decomposition during flow cell cycling by combining in-line UV-vis spectroscopy with multivariate curve resolution, which allows us to quantify decomposition kinetics and estimate UV-vis spectra of intermediate species/decomposition products. These results are being used to drive de novo computational design of new azobenzene molecules that can eliminate or substantially mitigate the identified decomposition pathways.
A Membrane-Electrolyte System Approach to Understanding Ionic Conductivity and Crossover in Aqueous Organic and Metalorganic Flow Batteries
Authors: George Thomas Young , Thomas Isabelle C. , Haya Naphtal O. , Deneen John P. , Wang Cliffton , Aziz Michael J. 
Published: September 2023

The ion exchange membrane is a critical component of most aqueous flow batteries, where it provides a transport medium for charge carrying ions while suppressing undesired crossover of redox active species. The all-vanadium redox flow battery (VRFB), the most developed flow battery chemistry to date, is also the system for which most studies of flow battery membranes have been done. These studies have shown that the concentration and composition of the acidic vanadium electrolytes influence water content in the membrane phase, and therefore influence the transport phenomena through the membrane pores. In the present work, we build on this understanding by evaluating the effects of iron(II/III) hexacyanide electrolyte concentration, pH, and cations on cation exchange membrane performance, to inform design of aqueous organic and metalorganic flow batteries (AORFBs).
The size and charge numbers of established redox active materials for AORFBs afford them lower crossover than metal ions like vanadyl or iron. However, many emerging AORFB chemistries with extreme stability use neutral or alkaline electrolytes where sodium or potassium, not protons, must carry ionic current through the membrane. In these flow batteries, the membrane resistance regularly contributes the most to polarization losses. The widely-used cation exchange membrane Nafion has a factor-of-ten reduction of conductivity in potassium form compared to when it is protonated in acidic environments. Ohmic resistance of the membrane is therefore a substantial limiting factor on practical current densities and power densities for battery operation.
In order to investigate the membrane-electrolyte system, we first describe simple methods for conductivity and electrolyte uptake measurements that can be used to screen a variety of membrane materials and electrolytes. We show the influence of pre-treatment, cation (sodium or potassium), supporting electrolyte, and iron hexacyanide concentration on Nafion conductivity and electrolyte uptake, and compare these results with a non-fluorinated Fumatech membrane (E-620). We also assess pre-treatment, concentration, and cation effects on ferricyanide permeability. Considering the membrane and contacting flow battery electrolyte as one system, our results emphasize that the total ion concentration of the electrolyte affects membrane water content, and there are conditions where additional supporting electrolyte can have a harmful effect on membrane conductivity. We also show that maximizing the concentration of iron hexacyanide by using mixed cation electrolytes results in increased membrane resistance, signifying that conductivity and volumetric capacity become a tradeoff.
A High-Power-Density Low-Temperature Heteropoly Acid Aqueous Redox Flow Battery
Authors: Ai Fei , Lu Yi-Chun 
Published: September 2023

Aqueous redox flow batteries (ARFBs) are promising technology for safe and long-duration energy storage owing to their flexible architecture decoupling power and energy, which is the key to achieving massive utilization of intermittent renewable energies (solar and wind power)1. However, the high-power density at low temperatures is prohibited by the weak stability, sluggish kinetics, and limited solubility of active materials. These challenges not only preclude the commercialization of ARFBs in the high-power density market (e.g., electric automobile) but also make the renewable electric grid vulnerable to severe weather fluctuations.
In this study, we describe a polyoxometalate-based active material with exceptionally fast redox kinetics and high electron solubility at low temperatures2. We optimize the charging process to achieve high electrochemical performance and will discuss factors that would influence solubility. We evaluate the kinetics of the polyoxometalate-based materials by rotating ring-disk electrodes measurement (RRDE) and adjust the electrolyte composition to increase the energy density and electrochemical stability of polyoxometalate-based electrolytes. We will discuss the full polyoxometalate-based ARFBs’ electrochemical performance, the influence of the supporting, and the possible degradation mechanism of the full cell (e.g., side reaction (hydrogen evolution, decomposition of the active materials) and crossover).

Acknowledgment:

The work is supported by a grant from the Research Grant Council (RGC) of the Hong Kong Special Administrative Region, China (project no. CUHK 14308622).

Reference:

(1) Yao, Y.; Lei, J.; Shi, Y.; Ai, F.; Lu, Y.-C. Assessment methods and performance metrics for redox flow batteries. Nature Energy
2021,
6 (6), 582.
(2) Ai, F.; Wang, Z.; Lai, N.-C.; Zou, Q.; Liang, Z.; Lu, Y.-C. Heteropoly acid negolytes for high-power-density aqueous redox flow batteries at low temperatures. Nature Energy
2022,
7 (5), 417.
Precipitation/Dissolution of Supersaturated V(III) Sulfate Electrolytes
Authors: Mouron Spencer , Cho Daniel , Li Yuanchao , Nguyen Trung Van 
Published: September 2023

Redox flow batteries (RFBs)-based storage systems have the unique feature of separate power generating and energy storage units that can be individually sized. RFBs can be used for days-long energy storage, but because of the low solubility of most ions and molecules in both aqueous and non-aqueous solvents,[1,2] scaling these RFB systems for days-long applications requires significant storage volume and floor area.
Our team has been working on a new storage method that significantly increases the energy storage density while still maintaining the traditional flow battery design.[3] This method involves storing the reactants as both soluble ions and an undissolved solid form, only the liquid containing soluble ions is circulated through the batteries. To achieve this, a solid form of Vanadium salt must be precipitated within the storage tanks, necessitating a study on the precipitation and dissolution of various vanadium salts. Past work has been done by our group on the Vanadium (IV/V) solution,[4] we now focus on the Vanadium (II/III) solution. This presentation will discuss the production of Vanadium (III) sulfate salt electrolytes, and the precipitation rate of said salt at oversaturation.

References

[1] V. Singh, S. Kim, J. Kang, and H. R. Byon, Nano Res.,
12, 1988-2001 (2019).
[2] K. Gong, F. Xu, J. B. Grunewald, X. Ma, Y. Zhao, S. Gu, and Y. Yan, ACS Energy Lett.,
1, 89-93 (2016).
[3] Y. Li and T. V. Nguyen, Provisional US patent application number 62/941,064 filed 2019/11/27, International Application No. PCT/US20/61455 filed 2020/11/20 (WO2021108244A1).
[4] Y. Li and T. V. Nguyen, J. Electrochem. Soc., 169, 110509 (2022).
Low-Tortuous and Dense Electrode for High-Energy Lithium-Sulfur Batteries
Authors: Feng Shuo , Fu Yucheng , Shi Lili , Anderson Cassidy , Lu Dongping 
Published: September 2023

Lithium-sulfur (Li-S) batteries feature a high theoretical capacity of 1675 mAh/g and hence is considered as a promising alternative to lithium-ion batteries. However, deployment of Li-S batteries has been hindered by the low practical energy and limited cycle life.1, 2 Reducing cathode porosity is essential to balancing the electrolyte distribution in Li-S cell, conserving more pore-filling electrolyte to extend cell cycle life.3-5 However, low-porosity electrodes built with nanosized sulfur/carbon (S/C) materials suffer from high tortuosity that significantly deteriorates electrode wetting and hence sulfur utilization. Enabling operation of high-loading sulfur electrodes under both low-porosity and lean-electrolyte conditions is still a challenge and is seldom discussed. In this study,6 we demonstrated a novel and facile strategy for constructing low-tortuosity through-pores across both vertical and planar directions of electrodes by casting large particles into single-particle-layer electrodes. Through multi-scale characterizations and simulations, correlations between material/electrode structures, electrolyte permeability, polysulfide migration, and sulfur reactions were elucidated. The high-loading and dense sulfur cathode fabricated by this method delivers a high specific capacity (>1000 mAh g-1) at a very low electrolyte/sulfur (E/S) ratio of 4 μL mg-1. This study provides a novel approach to reducing the tortuosity of dense sulfur electrodes by manipulating the porosity distribution, which would be also applicable to improving the rate capability of other high-energy electrodes. More details of the progress will be discussed at the meeting.
Reference.

Dörfler, S.; Althues, H.; Härtel, P.; Abendroth, T.; Schumm, B.; Kaskel, S., Challenges and Key Parameters of Lithium-Sulfur Batteries on Pouch Cell Level. Joule
2020,
4 (3), 539-554.

Xue, W.; Miao, L.; Qie, L.; Wang, C.; Li, S.; Wang, J.; Li, J., Gravimetric and volumetric energy densities of lithium-sulfur batteries. Current Opinion in Electrochemistry
2017,
6 (1), 92-99.

Lu, D.; Li, Q.; Liu, J.; Zheng, J.; Wang, Y.; Ferrara, S.; Xiao, J.; Zhang, J. G.; Liu, J., Enabling High-Energy-Density Cathode for Lithium-Sulfur Batteries. ACS Appl Mater Interfaces
2018,
10 (27), 23094-23102.

Kang, N.; Lin, Y.; Yang, L.; Lu, D.; Xiao, J.; Qi, Y.; Cai, M., Cathode porosity is a missing key parameter to optimize lithium-sulfur battery energy density. Nat Commun
2019,
10 (1), 4597.

Feng, S.; Liu, J.; Zhang, X.; Shi, L.; Anderson, C.; Lin, Y.; Song, M.-K.; Liu, J.; Xiao, J.; Lu, D., Rationalizing nitrogen-doped secondary carbon particles for practical lithium-sulfur batteries. Nano Energy
2022,
103.

Feng, S.; Singh, R. K.; Fu, Y.; Li, Z.; Wang, Y.; Bao, J.; Xu, Z.; Li, G.; Anderson, C.; Shi, L.; Lin, Y.; Khalifah, P. G.; Wang, W.; Liu, J.; Xiao, J.; Lu, D., Low-tortuous and dense single-particle-layer electrode for high-energy lithium-sulfur batteries. Energy & Environ. Sci.
2022.