bluuebunny/crossref_metadata_2025 huggingface dataset:
Electroless Encapsulation of C-Cloth with Sn and Sn-Cu Alloy for Li-Ion Battery Anode
Authors: Watson Venroy George , Kalu Egwu Eric , Yeboah Yaw D. , Weatherspoon Mark H. , Zheng Jim P
Published: February 2020

Over the last few decades a vast number of researchers have investigated various methods for the synthesis of tin alloy anode materials capable of repeated cycling, reduced tin pulverization, and capacity retention when used in lithium ion batteries (LIBs).1-3 In this study, we report the use of woven carbon cloth as high surface area template for the deposition of Cu and subsequent encapsulation with Sn via facile electroless coating method without the use of external power supply. The resulting material Sn-Cu@C-cloth was annealed at 200 OC and 400 OC and used as electrodes in LIB half-cells with Li metal as anode. Charge/discharge study at current density of 227 mAh/g indicated that Sn-Cu@C-cloth annealed at 200OC and 400 OC exhibited first cycle capacities of 745 mAh/g, and 1075 mAh/g, respectively, while the C-cloth substrate exhibited only 340 mAh/g. Preliminary results after fifty cycles indicated that the annealed Sn-Cu@C-cloth exhibited capacity retention of ~413 mAh/g. These results indicate that facile electroless encapsulation of carbon cloth as a cost effective approach can potentially be used to fabricate Sn and CuSn alloys anode materials.

References

[1] M. Winter, J.O. Besenhard, Electrochemical lithiation of tin and tin-based intermetallics and composites, Electrochimica Acta 45 (1999) 31.

[2] A.R. Kamali, D.J. Fray, tin-based materials materials as advanced anode materials for lithium ion batteries: A review, Rev. Adv. Mater. Sci. 27 (2011) 14.

[3] H. Kim, G.O. Park, Y. Kim, S. Muhammad, J. Yoo, M. Balasubramanian, Y.-H. Cho, M-G. Kim, B. Lee, K. Kang, H. Kim, J. M. Kim, W.-S. Yoon, New insight into the reaction mechanism for exceptional capacity of ordered mesoporous SnO2 electrodes via synchrotron-based x-ray analysis, Chem. Mater. 26 (2014) 6361.

Figure 1
(Invited) Electrochemical Manufacturing and Characterisation of Nanostructured Electrodes for Lithium Based Batteries
Authors: Rehnlund David , Ihrfors Charlotte , Nyholm Leif
Published: February 2020

Due to their high energy and power densities, lithium-ion batteries are the primary choice for application in consumer electronics. Although new electrode materials for Li-ion batteries are developed continuously, relatively little attention has so far been paid to the use of electrochemical methods in the manufacturing of battery materials. In the field of microbatteries, electrodeposition has, nevertheless, become an important technique for the manufacturing of current collectors, electrode materials and electrolytes [1]. During the last few years it has also been shown that electrochemically nanostructured electrodes lacking binders and other additives can facilitate the attainment of an improved understanding of the electrochemical reactions taking place in lithium based batteries.

This presentation will focus on the development of electrochemical approaches for the manufacturing and study of nanostructured electrode materials for lithium based batteries. It will be shown that electrodeposition can be used for the manufacturing of 3-D copper and aluminium [1] current collectors as well as the coating of these with thin layers of anode or cathode materials. Electrochemical manufacturing and characterisation of materials such as multilayered Cu/Cu2O nanorods [2], Sn/SnO2 particles [3] and TiO2 nanotubes (see Figure 1) will be discussed, as well as a new approach for the manufacturing of TiO2 nanotube size gradient based electrodes [4]. Some fundamental issues regarding the electrochemical processes in the electrochemically manufactured materials, including the formation of “cathodic passive layers” and “trapping of lithium” in current collectors and alloy forming electrode materials [5] and the electrodeposition of homogeneous lithium films on lithium electrodes (see Figure 1) will likewise be discussed.

References

[1] K. Edström, D. Brandell, T. Gustafsson, L. Nyholm, Electrodeposition as a tool for 3D Microbattery Fabrication, Electrochem. Soc. Interface, 20 (2011) 41.

[2] D. Rehnlund, M. Valvo, C. –W. Tai, J. Ångström, M. Sahlberg, K. Edström, L. Nyholm, Electrochemical fabrication and characterization of Cu/Cu2O multi-layered micro and nanorods in Li-ion batteries, Nanoscale, 7 (2015) 13591.

[3] S. Böhme, K. Edström, L. Nyholm, Overlapping and Rate Controlling Electrochemical Reactions for Tin(IV) Oxide Electrodes in Lithium-Ion Batteries, J. Electroanal. Chem., 797 (2017) 47.

[4] W. Wei, F. Björefors, L. Nyholm, Hybrid energy storage devices based on monolithic electrodes containing well-defined TiO2 nanotube size gradients, Electrochim. Acta, 176 (2015) 1393.

[5] D. Rehnlund, F. Lindgren, S. Böhme, T. Nordh, Y. Zou, J. Pettersson, U. Bexell, M. Boman, K. Edström, L. Nyholm, Lithium Trapping in Alloy forming Electrodes and Current Collectors for Lithium based Batteries, Energy Environ. Sci., 10 (2017) 1350.

Figure 1
(Invited) Electrochemical Synthesis of Nanostructured Materials Using Ionic Liquids for Metal-Ion Batteries
Authors: Lahiri Abhishek , Endres Frank
Published: February 2020

In the last two decades ionic liquids have evolved to be good electrolytes for the electrodeposition of metals and semiconductors, primarily due to their large electrochemical windows of up to ± 3V. However, only in the last couple of years significant interest in using electrodeposited materials from ionic liquids for applications in batteries has evolved, showing promising and versatile routes for electrode material synthesis.

In this lecture we will give an overview on the electrodeposition of metals such as Al, Zn [1, 2] and semiconductors such as Si, Ge [3, 4] from ionic liquids which have been applied to different metal-ion batteries. In the case of metals such as Zn, we will show how the addition of dopant salts and ionic liquid mixtures makes it possible to inhibit the formation of dendrites during Zn deposition/stripping. Also, electrodeposition of various silicon and germanium macroporous structures as well as nanotubes which have been used as anodes in Li-ion batteries will be shown [5, 6].

Lastly, we will give an insight into the less investigated subject of electroless deposition in ionic liquids [3, 7] and how it can be used to develop battery electrodes as well as to modify Si and Ge deposits for battery applications.

References

S. Zein El Abedin, A. Garsuch, F. Endres, Aus. J. Chem., 2012, 65, 1529-1533

Z. Liu, T. Cui, G. Pulletikurthi, A. Lahiri, T. Carstens, M. Olschewski, F. Endres, Angew. Chem. Int. Ed., 2016, 55, 2889-2893

A. Lahiri, T. Lu, N. Behrens, N. Borisenko, G. Li, F. Endres, ACS Appl. Mater. Interfaces., 2017, 9, 11350-11355

A. Lahiri, G. Li, M. Olschewski, F. Endres, ACS Appl. Mater. Interfaces., 2016, 8, 34143-34150

A. Lahiri, A. Willert, S. Zein El Abedin, F. Endres, Electrochim. Acta., 2014, 121, 154-158

X. Liu, J. Hao, X. Liu, C. Chi, F. Endres, Y. Zhang, Y. Li, J. Zhao, Chem. Commun., 2015, 51, 2064-2067

A. Lahiri, M. Olschewski, R. Gustus, N. Borisenko, F. Endres, Phys. Chem. Chem. Phys, 2016, 18, 14782-14786
Novel Electrochemical Sensor Concept for the Detection of Lead Contamination in Drinking Water
Authors: Liu Xinyu , Venkatraman Kailash , Akolkar Rohan
Published: February 2020

Lead contamination of drinking water is a widespread problem affecting people in developing as well as developed countries. While lead contamination levels can be monitored at water treatment facilities, drinking water may get contaminated with lead during its distribution. To ensure that drinking water ‘at the tap’ is not lead contaminated, it is essential to develop a low-cost, portable sensor for use in homes and offices. In the present talk, a novel electrochemical sensor concept which enables accurate detection of ppb-levels of Pb2+ in water will be outlined. The sensor works on the principle of underpotential deposition of lead (Pbupd) onto a Cu electrode followed by quantitative measurement of the hydrogen evolution reaction (HER) current on the partially Pbupd-modified Cu electrode surface. The basic operation of the electrochemical sensor involves the following steps (Figure 1): (i) A copper working electrode is immersed in a Pb2+-contaminated sample, and a suitable electrode potential is applied to it which facilitates the underpotential deposition of lead onto the copper surface. Depending on the Pbupd time and the Pb2+ concentration in the sample, the Pbupd coverage of the Cu surface increases gradually; (ii) The kinetics of electrochemical splitting of water to evolve hydrogen gas depends on the Pbupd coverage on the Cu electrode – higher the Pb coverage during step i, more sluggish is the hydrogen gas evolution during step ii. The degree of suppression of the HER kinetics (i.e., current) is measured, which then provides the Pbupd coverage (for a known deposition time) and thus the Pb2+ concentration in solution. In this presentation, we will demonstrate the feasibility of the above electrochemical sensor concept to achieve a detection limit of 10 ppb Pb2+ in water samples. Furthermore, we will present detailed analysis of the sensor response time using a mathematical diffusion-reaction model. Techniques to minimize interference effects due to other contaminants, and comparison between the sensor performance and standardized spectroscopic measurements of lead concentration will also be discussed. Ongoing work on building a portable electrochemical sensor prototype will be outlined.

Figure 1
(Invited) Synthesis and Electromagnetic Properties of Square-Symmetry π-Conjugated Phthalocyanato Metal-Organic Frameworks
Authors: Stassen Ivo , Dincă Mircea
Published: February 2020

Two-dimensional (2D) crystalline (semi)conductors, inspired by model systems such as graphene, silicenes and transition metal dichalcogenides, are a central topic of current research at the nanoscale. Exciting physical properties such as massless fermions, fractional quantum hall effects and flat-band ferromagnetism originate from the unique electronic band structures of these materials. Conductive 2D metal-organic frameworks (MOFs) are a recent and promising addition to these classes of materials due to features such as bottom-up tailorability and guest-accessible nanoporosity. Here, were present a new highly tunable platform of square-symmetry conductive MOFs. The electronic band structure of these materials is unique relative to the more common hexagonal (honeycomb) symmetry that characterizes many 2D materials and all previously reported π-conjugated MOFs. We will discuss the experimental and first-principles calculated physical properties of these new materials in relation to the hexagonal phases.
Gold Deposition Using Accelerating Adsorbates: From Superfill and Smoothing to Nanowire Growth
Authors: Josell Daniel , Moffat Thomas P.
Published: February 2020

Adsorbates based on a number of P-block elements are known to accelerate Au deposition from sulfite as well as cyanide electrolytes. However, the nature of deposits from an electrolyte-additive system, and from the different electrolyte-additive systems, varies substantially. Optically smooth planar deposits coupled with superconformal filling of patterned features such as trenches and vias can be obtained from sulfite-Pb (and cyanide-Pb) electrolytes. With other additives superconformal feature filling is also observed, but it manifests with a geometry more akin to the extreme bottom-up filling seen during Cu filling of through silicon vias. Perhaps most interesting, deposits ranging from optically smooth surfaces to dense arrays of uniformly oriented nanowires can be obtained from sulfite-Tl electrolytes through adjustment of only the applied potential. I will discuss how electroanalytical measurements, coupled with mechanistic models, can help us understand, and in some cases predict, observed deposition behavior.
(Invited) Tracking Hydrodynamic Signatures of Metal Nucleation Events Via Lateral Molecular Force Microscopy
Authors: Fermin David , Plana Daniela , Harniman Robert , Miles Mervyn
Published: February 2020

The direct visualization of local events leading to the formation of a critical nucleus remains as one of the most formidable challenges in electrodeposition. Recently, state-of-the-art video-rate scanning tunnelling microscopy has been able to follow lateral growth of Bi deposits with exquisite atomic resolution [1]. However, strong local potential bias between tip and substrate often leads to ‘shielding effects’, significantly decreasing local nucleation rates. Substrate-tip interactions in conventional atomic force microscopy also have a strong effect in local nucleation rate. In this contribution, we shall demonstrate a new approach to monitor individual nucleation events based on tracking local perturbations of hydration shells employing high-speed lateral molecular force microscopy (HS-LMFM).

A unique optical feedback mechanism lies at the center of the operating mode of HS-LMFM [2,3]. Under this configuration, the position of a vertically oriented probe (VOP) is tracked by measuring the scattering of the evanescent wave of a laser impinging under total internal reflection from the back of an optically transparent electrode. As the tip approaches the surface oscillating close to its resonant frequency, the oscillation frequency is affected by the visco-elastic properties of the various hydration layers. Changes in the VOP oscillations are optically detected by the scattering evanescent field. This approach enables monitoring interaction with individual hydration layers simultaneously with, but independent of, the optical feedback.

In these experiments, the tip is positioned at a distance in which shear force interactions with hydration layers of an In-doped SnO2 electrode (approximately 2.9 nm roughness level) become negligible [4]. As nucleation events are triggered, the hydration layers around individual nuclei move into a detectable range of the VOP, leading to changes in the oscillation frequency. Shear force maps uncover a highly dynamic landscape prior to the formation of stable nucleus. At constant potential, the stochastic formation and dissolution of nuclei can be observed in the sub-second time scale. The growth of a stable nucleus is also followed in real-time, illustrating the potential of this technique for probing complex phase formation phenomena at electrode surfaces.

References

Matsushima, H. et al.
Faraday Discuss.
193, 171-185 (2016).

Fletcher, J. M. et al.
Science
340, 595-599 (2013).

Antognozzi, M. et al.
Nat.
Phys.
12, 731-735 (2016).

Harniman, R.L. et al. Nat.
Commun.
8, 971 (2017)
Multivalent Metal Ions As Efficient Reducing Agents for Electroless Metal Deposition Processes
Authors: Norkus Eugenijus , Tamasauskaite-Tamasiunaite Loreta
Published: February 2020

In this study the possibility and conditions to use lower oxidation state metal ions as reducing agents for autocatalytic electroless metal deposition are discussed.

The theoretical background of such kind reactions is presented in the view of thermodynamics.

Kinetic data on electroless silver, copper, palladium and platinum deposition using Co(II)/Co(III) redox systems with different ligands are presented and discussed.

Ti(III)/Ti(IV) redox systems with different ligands were shown also to be suitable reducing agents for reducing of Pt(IV), Pd(II), Ni(II) and Co(II) to metallic state and formation of continuous metal layer on the surface to be plated.

The morphology of metal layers deposited using above-mentioned reducing agents was characterized by means of Field Emission Scanning Electron Microscopy (FESEM). Kinetics of metal deposition rate was investigated by means of the gravimetry or Electrochemical Quartz Crystal Microgravimetry (EQCM).
Redox Flow Batteries for Fast EV Charging and for Hydrogen Production for FCEVs
Authors: Girault Hubert H , Dennison Christopher R , Ligen Yorick , Vrubel Heron , Zanzola Elena , Reynard Danick , Amstutz Véronique , Peljo Pekka
Published: February 2020

A service station for electric vehicles (EVs) and fuel cell EVs (FCEVs) has been constructed based on a vanadium redox flow battery (200kW-400kWh). This battery is used to fast charge EVs using a DC-DC converter operating at 80kW.

We also operate two electrolyzers (one alkaline 50kW, one PEM 25 kW) to produce hydrogen. This hydrogen is dried, purified and stored at 200 bars. A service station for hydrogen has been built with reservoirs at 500 bars to fill a car (Renault Kangoo/Swiss hydrogen) operating at 350 bars and at 900 bars to fill a car operating at 700 bars (Hyundai).

We shall discuss the figures of merit of electric and hydrogen mobility and our experience to run a service station in the Alps.

We shall also present a new technology to produce hydrogen on demand and under pressure directly from a Vanadium (III)/(II) solution from the redox flow battery using a Mo2C catalyst. We shall also discuss the use of solid boosters to enhance the storage in the tanks of a redox flow battery.
Combined Theoretical and Experimental Approach to Next Generation Flow Cell Charge Carriers for Grid Scale Energy Storage
Authors: Chu Terry , Davis Benjamin L
Published: February 2020

Redox flow batteries are an attractive solution to the problem of grid-level energy storage however low energy densities and high costs are preventing them from becoming commercially viable on a large-scale. A promising approach to address low energy density is the utilization of non-aqueous solvents, assuming well designed charge carriers can utilize the wider potential window and be sufficiently soluble. In this presentation, we will detail the preparation, characterization, and electrochemical performance of metal complexes with polypyridyl ligands along with preliminary results from a bench-scale flow battery system.
(Henry B. Linford Award for Distinguished Teaching Address) Mathematical Modeling of Batteries
Authors: White Ralph E.
Published: February 2020

Mathematical modeling of batteries on the continuum scale will be reviewed in this presentation by way of several examples taken from my career. The purpose of such modeling is usually to develop a model that can be used to make predictions of the performance and perhaps the degradation of a battery of interest. Typically, we seek a model that is as simple as possible, but does not “throw the baby out with the bath water.” In addition, we seek a model that does not require significant computation time since it is necessary to validate the model based on experimental data. It has been and still is a challenge to develop a model of a battery of interest in a timely manner so that it will be useful in industry. Fortunately, software such as COMSOL Multiphysics is available now to assist in the development of models of batteries and includes a significant library of such models. Several examples of industrially useful mathematical models of batteries will be presented.
High Performance Reversible Hydrogen-Vanadium Fuel Cell for Electrical Energy Storage
Authors: Nguyen Trung Van , Verma Ankit
Published: February 2020

The hybrid reversible hydrogen-vanadium fuel cell [1,2] offers a feasible solution for storing electrical energy from the grid or intermittent renewable energy sources such as wind and solar. This system is an attractive alternative to the all-vanadium system due to the 50% reduction in the amount of vanadium solution required. This two-phase hybrid system also allows cross-over species to be separated and reused. In this presentation, the performance (cell voltage and power density versus current density and self-discharge rate) of this system at elevated temperatures (40oC and 50oC) will be discussed.

References:

Yufit, B. Hale, M. Matian, P. Mazur and N. Brandon, J. Electrochem. Soc., 160, A856 (2013).

Regis P. Dowd Jr., Vikram Lakhanpal, and Trung Van Nguyen, Electrochem. Soc., 164, F564 (2017).

Figure 1
Probing the Effects of Various Electrocatalysts on Aqueous Vanadium Redox Flow Battery Performance
Authors: Shah Andrew , Pierson Meghan , Joo Yong Lak
Published: February 2020

It has become increasing clear that renewable electricity can be generated on a large scale through a variety of different methods. While this progress has begun to decarbonize baseload electricity generation, the intermittent nature of the required resources has proven difficult to incorporate into regional electrical grids. Grid-scale electricity storage methods are a promising solution to the inefficiencies associated with unpredictable electricity generation. Redox flow batteries have demonstrated the ability to be used as a reasonably low-cost, long-term electrical storage method. Specifically, vanadium redox flow batteries (VRBs) have been of special interest due to their chemical stability, long life cyclability, and potential for high capacity electrical storage. One of the main factors limiting market penetration of redox flow batteries in energy storage portfolios is the high capital cost associated with this comparatively low energy density technology. To this end, many current research efforts focus on improving the energy density of VRBs to warrant this cost in the long term.

This work focuses on improving the energy density of VRBs by probing the effects of a variety of different metal electrocatalysts. This process uses metal salts to form catalytically active nanoparticles on the surface of the anode to improve the kinetics of the anodic reaction in the VRB. The systems of interest in this study involved using tin, copper, and lead metals deposited on the surface of the anode using a variety of techniques. The direct reduction of metal salts results in the formation of nano-scale and micron-scale electroplated particles on the surface of the anode, which can be used to improve the kinetics of the sluggish anodic reaction in VRBs. This work shows that when as little as 0.02 M concentrations of tin chloride are added to 1.0 M vanadium electrolyte, electrochemically reduced tin nanoparticles have excellent catalytic properties toward the anodic reaction, improving current densities by over 30% and improving the overall capacity of the battery. There were also some synergistic effects observed when the tin salts were coupled with copper salts, further improving the capacity of the battery. A series of methods were used to probe the effects of synthesized lead particles as well. We will present how these processes can have a dramatic effect on increasing both capacity and energy density of aqueous vanadium redox flow batteries.
Improving Electrochemical Performance of The Layer-Structured Ncm Cathode Materials For Large-Scale Lithium Ion Batteries
Authors: Kim Hyun-Soo , Sim Sungju , Jin Bong-Soo
Published: February 2020

Ni-rich layered LiNixCoyMn(1-x-y)O2 (x≥0.8) has been considered as promising candidate cathodes due to their large specific capacity, high rate capability and low cost. However, Ni-rich materials suffer from severe capacity fading, especially, when cycled at high temperatures due to the formation of highly reactive Ni4+ at charge state. Ni4+ has strong oxidizing property and the reaction between Ni4+ and the electrolyte will be accompanied by gas evolution, which causes severe swelling of the cell. Moreover, the formation LiOH and Li2CO3 on the surface is prone because of residual lithium on the surface, which is remained dut to an excess of lithium to creat a well ordered layered phase. The reaction with electroytes negatively impact the cycling performance by decomposing electrolytes. Therefore, it is necessary to improve the structure and interfacial stability, and many studies have indicated coating and doping approach. The coating for NCM materials is often used with stable metal oxides such as ZrO2, Al2O3, TiO2, SiO2 and Li2ZrO, and the commonly used dopant elements are Al, Mg, Ti, Zr and Fe.

In this work, TiO2 coated and Ti doped LiNi0.8Co0.1Mn0.1O2 were synthesized at the same time to improve the structure stability and suppress the side reaction with electrolytes. TiO2 nano-powder as a raw material was used to coating and doping through a convenient solid state synthesis process. As a result, the electrochemical performance of LiNi0.8Co0.1Mn0.1O2 cathode was enhanced.
Diagnosis of a Commercial LI ION Batteries
Authors: Gualous Hamid , EL Mejdoubi Asmae
Published: February 2020

The main challenge with lithium-ion batteries in vehicular applications is aging. It is known that the battery aging is sensitive to various factors such as current, temperature and depth of discharge. These elements have a considerable impact on the loss of the battery’s capacity, as well as on the increase of the internal resistance. So, these two parameters can be considered as the aging indicators. However, these indicators are not measurable and they must be estimated. In the first part of this study, we present an analysis of the aging of lithium-ion batteries in order to predict their failures. The comprehension of aging can retroact on the operating conditions in order to improve reliability. Thus, the work carried out involves the experimental analysis of a LiFePO4 battery’s calendar aging under different discharge currents and temperatures.

In order to estimate the aging indicators and evaluate the aging evolution, the second part of this study proposes a hybrid State-of-Charge (SOC) and State-of-Health (SOH) estimation technique for lithium-ion batteries according to surface temperature variation. The hybrid approach uses an adaptive observer to estimate the SOH while an extended Kalman filter is used to predict the SOC. Unlike other estimation methods, the closed-loop estimation strategy takes into account the surface temperature variation and its stability is guaranteed by Lyapunov direct method. In order to validate the proposed method, experiments have been carried-out under different operating temperature conditions and various discharge currents. Results highlight the effectiveness of the approach in estimating SOC and SOH for different aging conditions.
Two Electron Viologen Anolyte Materials for Neutral Aqueous Organic Redox Flow Batteries
Authors: DeBruler Camden , Hu Bo , Luo Jian , Liu Leo
Published: February 2020

Organic redox flow batteries provide a compelling avenue to advance large-scale energy storage due to the synthetic tunability and sustainability of organic active materials. Particularly, aqueous organic redox flow batteries possess attractive technical merits including high current and power performance, low costs, low toxicity, and safe operation. Through rational molecular engineering, a family of two-electron storage viologen anolyte materials were synthesized with the goal of boosting the cell voltage and capacity of organic aqueous redox flow batteries. These viologen anolytes have a theoretical capacity up to 96.5 Ah/L in H2O, and reduction potentials as low as -0.78 V vs. NHE. In flow battery testing, these compounds showed outstanding two-electron cycling performance when paired with (ferrocenylmethyl)trimethylammonium chloride as a cathode: cell voltage up to 1.38 V, peak power density up to 130 mW/cm2, capacity retention up to 99.99% per cycle, and energy efficiency up to 65% at 60 mA/cm2. Pairing a two-electron viologen anolyte with a TEMPO catholyte in an aqueous flow battery as a proof-of-concept delivered two-electron cycling with a cell voltage up to 1.72 V. This represents the highest cell voltage reported for an organic aqueous redox flow battery.
Electrochemical Properties of Lithium Based Liquid Metal Battery with Tin-Bismuth Cathode Materials
Authors: Yeo Jae-Seong , Lee Junghun , Yoo Eun-Ji , Seo Ilsung
Published: February 2020

Reliance on diesel fuel in military operations is a weak point due to the challenge of transporting fuel through hostile regions. To reduce fuel consumption and emissions, military microgrids are now considered as a solution to address its needs for improved energy security and reliability of military bases. Particularly, in military microgrids, stationary energy storage system plays a critical role in guaranteeing the microgrids stability and reliability. Recently, research into liquid metal battery has been ramped up for applications in smart grid energy storage system due to the inherent advantages of long cycle life, simple fabrication process, and low cost of materials. D. J. Bradwell et al. have initially proposed magnesium-antimony (Mg‖Sb) liquid metal battery which exhibits 97%, 71%, and 69% of Coulombic, voltage, and energy efficiencies, respectively. However, Mg‖Sb chemistry is not consistent enough for practical use in smart grid energy storage system due to the high operating temperature of 700°C and low discharge voltage of ca. 0.21 V. To overcome such problems efficiently, lithium metal has recently attracted attention as alternative anode material because of its low melting point (181°C), low electronegativity, and the lowest solubility in molten salts. X. Ning et al. have reported lithium-bismuth (Li‖Bi) liquid metal battery operating at a temperature of 550°C. K. Wang et al. have reported lithium-antimony-lead (Li‖Sb-Pb) operating at a temperature of 450°C. However, lead can leave behind serious environmental and human health problems. In this study, we adopted eutectic tin-bismuth (Sn-Bi) alloy as cathode material because it is widely used for lead-free solder material in electronics due to its low melting point of 139°C. We have investigated the electrochemical properties (Coulombic, voltage, and energy efficiencies) of pure tin and bismuth as well as eutectic tin-bismuth alloy to evaluate the effect of adding bismuth into tin. After charging and discharging of lithium-tin-bismuth (Li‖Sn-Bi) liquid metal battery, microstructural analysis using scanning electron microscope and X-ray computational tomography was also carried out to investigate alloying/de-alloying reactions of lithium into tin and bismuth.
Enhanced Electrochemical Properties of Lithium-Bismuth Liquid Metal Battery Via the Introduction of Tellurium Cathode Materials
Authors: Lee Junghun , Yeo Jae-Seong , Yoo Eun-Ji , Seo Ilsung
Published: February 2020

Large-scale energy storage technology is of vital importance as a result of energy demand from renewable energy sources, such as solar and wind. Recently, liquid metal battery as a large-scale stationary energy storage system has attracted much attention due to the inherent advantages of long lifetime, low cost, and facile battery fabrication. Liquid metal battery is composed of three liquid layers that are self-segregated on the basis of their density differences and mutual immiscibility. Most of researches into liquid metal battery are now focused on lithium anode based battery cell due to a low melting point (181°C) of lithium, its low solubility into molten salts, and extremely high ionic conductivities and relatively low melting points (350-430°C) of lithium halides electrolyte. The low melting point of lithium based materials is attributable to reduce the cell operating temperature below 550°C. X. Ning et al. have reported lithium-bismuth (Li‖Bi) liquid metal battery operating at a temperature of 550°C which exhibits a median discharge voltage of 0.67 V. To facilitate the use of lithium anode based liquid metal battery, it is necessary to increase a median battery operating voltage which is determined by anode-cathode material combinations. This study investigated the effects of tellurium (Te) as cathode materials on the electrochemical properties (energy efficiency and cyclability) of lithium-bismuth liquid metal battery. Microstructural and phase analysis of positive electrode using SEM and XRD was performed to investigate alloying and de-alloying reactions.
Electrochemical Assessment of Molten NaI-AlCl3 Catholytes for Sodium Batteries
Authors: Percival Stephen , Small Leo J. , Allcorn Eric , Spoerke Erik D.
Published: February 2020

Large scale electrical energy storage is a key piece of the next generation electrical grid infrastructure. Sodium batteries offer great promise as safe, low cost and high energy density storage technologies that can be utilized to meet the growing demand for these types of grid scale storage systems. We are exploring a fully molten sodium battery system that operates at low to intermediate temperatures and provides inherent safety for a large scale battery application. Here we characterize the electrochemical properties of new molten salt catholyte chemistries that enable high performance cycling behavior at lower the operating temperature. We present electrochemical analysis of candidate NaI-AlCl3 molten salt catholytes at various temperatures and compositions. We find concentration dependencies on the iodide oxidation potentials as well as the observed current densities. Insight from these studies reveal catholyte compositions that can support high current densities and good cycle life that would be critical to reliable battery performance. Understanding the phase behavior of these salt compositions is key to optimizing the catholyte performance and a preliminary phase diagram is used help explain the promising electrochemical observations. For example, solids present in the catholyte at very high or very low NaI concentrations hinder mass and charge transport to electrode surfaces. Successful understanding and manipulation of this phase space will enable increases in catholyte performance, both in terms of lower operating temperatures and also increased current densities for improved molten sodium batteries for grid scale energy storage.

Sandia National Laboratories is a multi-mission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
A “Non Zebra-Type” Sodium Metal Rechargeable Batteries with Low Materials Cost and High Performances
Authors: Chang Hee Jung , Lu Xiaochuan , Bonnett Jeff F , Sprenkle Vincent , Li Guosheng
Published: February 2020

Designing secure and reliable large scale energy storage systems is extremely important to make efficient use of renewable energy as well as to reduce reliance on non-renewable fossil fuels. Among energy storage technologies, sodium (Na)-beta alumina batteries (NBBs) have gained significant attention due to long cycle life, high energy density, and superior safety. However, there have been challenges that obstacle their practical use, such as high operating temperatures and expensive cathode materials.

Two NBB chemistries, such as sodium-sulfur (Na-S) battery and sodium metal halide (Na-MH) battery, have been extensively studied in the past. In this study, we introduce a novel concept of Na-metal battery using low-cost and earth-abundant metals in a planar cell configuration. The novel battery system is operated at a temperature below 170°C to maintain the electrode materials in a liquid state, which is much lower than the reported temperatures applied for the conventional NBB technologies. Various galvanostatic tests were conducted to investigate the optimized conditions.

Due to the lower operating temperature, the use of inexpensive cathode materials and high energy efficiency, our “Non ZEBRA-type” Na-metal system can offer further cost reduction, high safety, and reliability for future energy storage systems.
Strategies for Improved Depth-of-Discharge of Zinc-Air Flow Batteries
Authors: Mahlendorf Falko , Fuchs David , Müller Christoph , Heinzel Angelika , Heinemeyer Thea , Schwarz Christoph , Schneider Andreas , Behrens Peter
Published: February 2020

As one of the proposed post lithium-ion technologies, zinc-air batteries have received revived interest in the recent years, which is driven by the increased demand of high-performance, efficient, safe and environmentally friendly energy storage solutions. These energy storage systems need to address variable power, capacity and profitability requests. Zinc-air batteries with specific energy density higher than lithium-ion and low-cost, highly available, eco-friendly active materials are suitable to fulfill these requirements. The use of a flow battery type with zinc-particles suspended in alkaline solution (zinc-slurry) in addition with high performance oxygen-reduction electrodes enables the development of high-power zinc-air batteries. This setup also enables the independent scaling of capacity and power.

The cooperative project, ZnMobil, founded by the Federal Ministry of Economic Affairs and Energy in Germany combines the experience of industrial and academic partners (Covestro Deutschland AG; Grillo-Werke AG; VARTA Microbattery GmbH; Accurec Recycling GmbH; Technical University Freiberg, Gottfried Wilhelm Leibniz University Hannover; University of Duisburg-Essen; the fuel cell research center ZBT GmbH) to develop a high-performance and low-cost zinc-air flow battery.

Here we present strategies to improve the depth-of-discharge of zinc-air flow batteries. The battery system consists of a 100 cm² copper plate as current collector for the zinc-suspension electrode and an oxygen reduction electrode with gas-diffusion layer (supplied by Covestro). The zinc-slurry contains zinc particles (supplied by Grillo) suspended in alkaline solution (30 wt-% KOH) and stabilized with polyacrylic acid.

The battery performance and depth-of-discharge were measured for several additives added to the zinc-slurry. Furthermore, the influence of the discharge current density on the depth-of-discharge was evaluated for these setups. Depending on the current density and additive selection, it is possible to achieve depth-of-discharge up to 90 %.
Electrochemical and EPR Measurements of Vanadium Redox Couples for All Vanadium Redox Flow Batteries
Authors: Tiano Sophia , Arruda Thomas M , Lawton Jamie S.
Published: February 2020

Redox flow batteries (RFBs) are promising solutions to large scale energy storage, in particular to leverage power generated by intermittent renewable resources such as wind and solar. Vanadium RFBS (VFRBs) work by storing energy in the form of vanadium ions in solution via the following reactions:

VO2+ + H2O → VO2
+ + 2H+ + e- (1)

V3+ + e- → V2+ (2)

In the case of the VRFB, crossover of vanadium species from one side of the battery to the other causes significant issues including self-discharge, electrolyte imbalance and transport problems. Understanding the fundamental transport properties is essential to mitigating these issues and bringing the technology closer to market.

This study involves fundamental measurements of VOSO4 solutions in sulfuric acid electrolyte. The effect of sulfuric acid concentration has been studied by electron paramagnetic resonance spectroscopy, electrochemical methods (cyclic voltammetery, chronoamperometry, Levich type treatment of linear sweep voltammetry and electrochemical impedance spectroscopy) as well as other physiochemical characterization techniques including viscosity. Results will include interpretation of the EPR spectra and electrochemical techniques and related values obtained for the hydrodynamic radius of the vanadium species under investigation. Cyclic voltammograms have been analyzed for k0 by both fitting analysis and the treatment of Kingler et al.1 and are in good agreement. In addition, values of diffusion coefficient have been determined by several electrochemical techniques and EPR and are in good agreement.

R. J. Klingler and J. K. Kochi, J. Phys. Chem., 85, 1731–1741 (1981) http://pubs.acs.org/doi/abs/10.1021/j150612a028.
Developing New Chemistry for Redox Flow Batteries
Authors: DeBruler Camden , Hu Bo , Luo Jian , Moss Jared , Sam Alyssa , Liu T. Leo
Published: February 2020

Aqueous organic redox flow batteries (AORFBs) have emerged as an attractive alternative RFB technology because redox active organic molecule materials are synthetically tunable, sustainable, and potentially low cost. The presentation will cover our recent research efforts in developing two electron storage viologen molecules as anolyte materials for AORFBs. These viologen anolytes in neutral NaCl solutions have a theoretical capacity up to 96.5 Ah/L in H2O and exhibit a low reduction potential down to -0.78 V vs NHE. The neutral aqueous flow battery demonstration of two two-electron storage viologen molecules with (ferrocenylmethyl)trimethylammonium chloride (FcNCl) delivered up to 1.38 V cell voltage, and outstanding battery performance including a power density up to 130 mW/cm2, capacity retention up to 99.99% per cycle, and energy efficiency up to 65% at 60 mA/cm2. When paired with a TEMPO catholyte, a 1.72 V total organic RFB was also demonstrated. In addition, a fundamental study of the redox couple of [Fe(CN)6]4+/3+ in different supporting electrolytes with pH from 7 to 14 will be presented. We found that the redox couple functions best at neutral or near neutral conditions in RFBs. The entire presentation emphasizes that fundamental understandings of redox active electrolytes at molecular level are crucial to develop new generations of redox flow batteries for large scale and dispatchable renewable energy storage.

References: (1) DeBruler C.; Hu, B.; Moss, J.; Liu, X. Luo, J.; Sun, Y; Liu, T. L.*, Chem, 2017, in press. (2) Luo, J.; Sam, A.; Hu, B.; DeBruler C. Liu, T. L.* Nano Enegry, 2017, 42, 215-221. (3) Hu, B.; Seefeldt, C., DeBruler C.; Liu, T. L.* , J. Mater. Chem. A 2017, 5, 22137-22145. (4) Hu, B.; DeBruler C., Rhodes, Z.; Liu, T. L.*, J. Amer. Chem. Soc., 2017, (5) Liu, T.;* Wei, X.; Nie, Z.; Vince, S.; Wang, W. Adv. Energy Mat. 2016, 6, 1501449. (6) Filed US Patents covering applications of water soluble viologen, ferrocene derivatives, and TEMPO for RFBs. (7) Group website: www.tianbiaoliu.org.
Redox Reaction of Tris(2,2'-bipyridine)Iron Complexes on Carbon Fiber Dispersed in a Solvate Ionic Liquid
Authors: Katayama Yasushi , Sugiyama Masaru , Yoshii Kazuki , Tachikawa Naoki , Serizawa Nobuyuki
Published: February 2020

Redox flow batteries have attracted much attention as the large-scaled energy storage device for such renewable energy sources as solar cells and windmills. Typical redox flow batteries use aqueous electrolytes because of low cost, low toxicity and high safety. However, the electromotive force of the redox flow batteries using aqueous electrolytes is limited by the electrochemical potential window of the aqueous electrolytes. The enlargement of the electromotive force is expected by using non-aqueous aprotic electrolytes. Although aprotic organic electrolytes are typical of non-aqueous electrolytes, flammability of organic solvents is unfavorable for the large-scaled batteries from the point of view of safety. The equimolar mixture of lithium bis(trifluoromethylsulfonyl)amide (LiTFSA) and tetraglyme (G4) has been known to form the solvate ionic liquid consisting of a stable complex cation, [Li(G4)]+ and an anion, TFSA– [1]. The solvate ionic liquid has several favorable properties, such as high thermal stability, high Li ion concentration and low vapor pressure. In the present study, the redox reaction of tris(2,2'-bipyridine)iron(III/II) complexes, [Fe(bpy)3]3+/2+, has been investigated in the solvate ionic liquid containing carbon fiber as an electronic conductor aiming at its application to non-aqueous redox flow batteries.

The redox reaction of [Fe(bpy)3]3+/2+ was observed at 0.36 V vs. Ag|Ag(I), which was corresponding to about 4 V vs. Li|Li(I), in [Li(G4)]TFSA containing 10 mM [Fe(bpy)3](TFSA)2. The diffusion coefficients of [Fe(bpy)3]2+ and [Fe(bpy)3]3+ were estimated to be 4.4 × 10–8 and 3.1 × 10–8 cm2 s–1, respectively, at 25 °C. The slow diffusion of the electroactive species was ascribed to the high viscosity of [Li(G4)]TFSA (122 mPa s [2]) and disadvantageous to battery application because the faradaic current is limited by diffusivity of the species. In order to diminish the diffusion limitation of the faradaic current, carbon fiber was added to the solvate ionic liquid as an electronic conductor. The carbon fiber was dispersed homogeneously in the solvate ionic liquid. The electronic conduction through the carbon fiber was confirmed by electric conductivity measurement. The redox reaction of [Fe(bpy)3]3+/2+ was found to be possible on the carbon fiber dispersed in the solvate ionic liquid. The reversible charge-discharge of a cell composed of Li anode and the solvate ionic liquid containing [Fe(bpy)3]3+/2+ and the carbon fiber using a solid-state Li ion conductor was confirmed to be possible with the average cell voltage of 3.8 V and the coulombic efficiency of 99%.

References

[1] K. Yoshida, M. Tsuchiya, N. Tachikawa, K. Dokko, and M. Watanabe, J. Phys. Chem. C, 115, 18384 (2011).

[2] H. Hirayama, N. Tachikawa, K. Yoshii, M. Watanabe, and Y. Katayama, Electrochemistry, 83, 824 (2015).
2,1,3-Benzothiadiazole Derivatives As Anolyte Materials for Non-Aqueous Redox Flow Batteries
Authors: Zhang Jingjing , Huang Jinhua , Duan Wentao , Kowalski Jeffrey A , Hu Bin , Shkrob Ilya A , Assary Rajeev , Brushett Fikile R. , Wei Xiaoliang , Zhang Lu
Published: February 2020

2,1,3-Benzothiadiazoles(BzNSNs) are a key class of analyte materials for non-aqueous redox flow batteries (RFBs).1, 2 Understanding relationships between structural modifications and electrochemical properties is essential for designing energy-dense redox-active organic materials (ROMs) based on the BzNSN scaffold. This talk will describe a series of BzNSN derivatives with various electron-donating or -withdrawing groups as the anolyte materials for non-aqueous RFBs. Systematic investigations have been conducted to elucidate the substituents effects on the solubility, redox potentials, and stability of the corresponding radical anions. Also, the effects of inorganic and organic supporting electrolytes on the stability of the radical anions were extensively studied. Parasitic reactions that involve the sulfur loss and the oligomer formations are shown to restrict the long-term stability of these radical anions, yet the BzNSN molecules are among the leading performing energy-dense ROMs found to-day.

References

X. Wei, W. Duan, J. Huang, L. Zhang, B. Li, D. Reed, W. Xu, V. Sprenkle and W. Wang, ACS Energy Letters, 1, 705 (2016).

W. Duan, J. Huang, J. A. Kowalski, I. A. Shkrob, M. Vijayakumar, E. Walter, B. Pan, Z. Yang, J. D. Milshtein, B. Li, C. Liao, Z. Zhang, W. Wang, J. Liu, J. S. Moore, F. R. Brushett, L. Zhang and X. Wei, ACS Energy Letters, 2, 1156 (2017).

Figure 1
Materials Development for Aqueous Organic Redox Flow Batteries
Authors: Wei Xiaoliang , Hollas Aaron , Yang Zheng , Huang Jinhua , Murugesan Vijayakumar , Walter Eric , Li Bin , Nie Zimin , Reed David , Zhang Zhengcheng , Wang Wei , Sprenkle Vincent
Published: February 2020

The scalability and design flexibility make redox flow batteries highly advantageous for grid-scale energy storage applications. Traditional flow batteries are based mainly on inorganic metal species, but their broad market penetration is greatly limited by the low energy density and high chemical costs. In this regard, water-soluble organic redox-active materials have demonstrated competitive property and performance merits, which makes them promising materials candidates to enable next-generation flow batteries.1

In this contribution, we will report our recent accomplishments in developing new aqueous organic flow battery materials and systems. A variety of high-performance organic candidates with different structures and reaction mechanisms have been identified and investigated that have produced decent cyclability over extended charge/discharge cycling. We will introduce our generic approaches to gain fundamental structure-activity-stability relationships for organic redox-active materials, including solvation interactions, electronic structures, and failure mechanisms. These understandings have greatly guided our materials development strategies to achieve significant improvement in solubility, cell voltage, and stability.

References

X. Wei, W. Pan, W. Duan, A. Hollas, Z. Yang, B. Li, Z. Nie, J. Liu,D. Reed, W. Wang, V. Sprenkle, Materials and Systems for Organic Redox Flow Batteries: Status and Challenges. ACS Energy Lett.
2017,
2, 2187.

Figure 1