bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electrochemical Analysis of Chromium Acetylacetonate for Nonaqueous Flow Batteries
Authors: Saraidaridis James Demetrios , Monroe Charles W 
Published: February 2020

Although redox flow batteries (RFBs) provide the advantage of decoupled energy and power density useful for grid storage applications, current state-of-the-art technologies have yet to achieve widespread commercial success. Cost per unit energy storage capacity presents the largest barrier to this goal [1].
Wide voltage gaps between redox potentials, capacity for multiple redox reactions, and ability to serve as both negative and positive electrolyte (ability to disproportionate) make chromium acetylacetonate [Cr(acac)3] attractive for RFB applications [2]. With multiple redox potentials separated by >3 V, as shown by the cyclic voltammogram in Figure 1, cell potentials can be raised significantly above state-of-the-art aqueous RFBs, which are limited within a ~1.5 V operating window. Employing the same Cr(acac)3 solution in both electrolyte reservoirs delivers a truly symmetric single-metal RFB and can eliminate the need for costly ion-selective separators. Large operating potentials and inexpensive stack materials will help raise theoretical maximum energy density and mitigate cost concerns.
In spite of clear advantages, operation of nonaqueous Cr(acac)3 RFBs display low voltage efficiency [2]. With the aim of elucidating a potential cause of this low efficiency, we investigated the electrochemical kinetics of nonaqueous chromium acetylacetonate on various electrodes, focusing on the redox couples centered at -2.1 & 1.2 V vs. Ag/Ag+ (shown in Figure 1). Initial linear-sweep voltammetry experiments on Au, Pt, and C microelectrodes depicted more complicated redox behavior than originally hypothesized. We will discuss the ramifications of this behavior with regard to reaction mechanisms, while also addressing how these observations can further guide RFB design for nonaqueous Cr(acac)3 systems.

Figure 1: Cyclic and normalized linear-sweep voltammograms of 0.01 M Cr(acac)3/0.05 M TEABF4 in acetonitrile, Pt WE (50um) & CE, 500 mVs-1 and 1 mVs-1 (insets), <1ppm O2/H2O, ambient temperature.
[1] S. Eckroad. EPRI Report 1014836. 2007.
[2] Q. Liu et al. Electrochem. Comm. 12 (2010): 1634.
New Development in the Alkaline-Based Hydrogen-Bromine Fuel Cell
Authors: Nguyen Trung Van , Yarlagadda Venkata , Konwar Dhrubajit , Chan Kwong-Yu 
Published: February 2020

The hydrogen bromine (H2-Br2) fuel cell system is an attractive system for electrical energy storage because of its high round-trip conversion efficiency, high power density capability, and anticipated low costs. The hydrogen-bromine fuel cell system can be operated in the acid or alkaline modes as shown in Figure 1.
Figure 2 shows schematics of the cell configuration of these two systems. The main difference is the additional compartment for KOH solution between the negative electrode and the membrane for the hydrogen reactions.
The alkaline H2-Br2 fuel cell was studied recently by us because of its advantages over the acid system such as higher cell potential, low cost catalyst for the hydrogen evolution and oxidation reactions and lower corrosivity. The results from that study confirmed that this system can deliver a higher cell voltage and that the reaction rates of the hydrogen and bromine reactions in alkaline solution (KOH) were as fast as in acid solution (HBr). The results also showed that high power density performance could be obtained and its current performance was limited by high cell internal resistance, due mainly to high ionic resistance of the potassium ion (K+) conducting membrane. [1]
This presentation will discuss new development in the alkaline H2-Br2 fuel cell.

Reference:

1) T.V. Nguyen, V. Yarlagadda, G. Lin, G. Weng, C.-Y. Li, and K.-Y. Chan, “Comparison of Acid and Alkaline Hydrogen-Bromine Fuel Cell Systems,” ECS Transactions, Vol. 58, No. 37 (2014).

Acknowledgements

This work was funded by the National Science Foundation through grant number EFRI-1038234 and Research Grants Council of Hong Kong through a General Research Fund (GRF HKU 700210P).
Aqueous Manganese-Based Electrolytes for Redox Flow Batteries
Authors: Swartz Christopher R , Lipka Stephen M , Rogers Fon , Chen Rong , Kodenkandath Thomas 
Published: February 2020

Redox flow batteries (RFBs) are an emerging technology suitable for large-scale, stationary energy storage applications, including grid storage. Redox flow batteries are capable of storing high amounts of both energy (MWh) and power (MW).1 One principle advantage of flow batteries is the ability to decouple the energy density and power density of the system, and scale both independently. The all-vanadium RFB represents the current state-of-the-art in flow battery technology, and features several advantages, including rapid response times, high depth of discharge, long cycle life, and good cell performance metrics (i.e. efficiencies). Anolyte and catholyte cross-contamination is eliminated through the use of the same active metal cation in both compartments of the cell.
Issues associated with the vanadium RFB include a low cell voltage (1.26 V), the use of expensive membranes including Nafion®, and the relatively high cost of vanadium, leading to expensive electrolytes.2 The development of anolytes with higher reversible potentials than VO2+/VO2
+, along with electroactive species featuring higher natural abundance and lower cost than vanadium, represents an attractive alternative to vanadium-based anolytes. Flow battery anolytes based on the Mn2+/Mn3+ redox couple have been reported in the literature, and the high standard electrode potential of Mn2+/Mn3+ (1.51 V) has been utilized in manganese anolyte (Mn2+/Mn3+)/vanadium catholyte (V2+/V3+) redox flow batteries, featuring a theoretical open circuit voltage of 1.77 V.2,3 The usage of manganese anolytes can lead to higher cell voltages (Figure 1) and cheaper anolytes, but the disproportionation reaction of Mn3+ to Mn2+ and MnO2 is a technical issue that needs to be resolved in order for manganese-based anolytes to find widespread utility in redox flow batteries.2

This presentation will disclose our investigations on the development of manganese-based anolytes for redox flow batteries. The effect of various additives on electrolyte stability and electrochemical kinetics for the Mn2+/Mn3+ redox couple will be quantified using cyclic voltammetry, RDE measurements, electrochemical impedance spectroscopy, overpotential measurements, and full-cell testing (constant current charge/discharge) of Mn/V redox flow batteries (Figure 2).
References
1) Wang, W. et al. J. Power Sources.
2012, 216, 99.
2) Xue, F.-Q. et al. Electrochimica Acta.
2008, 53, 6636.
3) Hong, T.; Xue, F. “Investigation on manganese (Mn2+/Mn3+)-vanadium (V2+/V3+) redox flow battery.” 2009 Asia-Pacific Power and Energy Engineering Conference (APPEEC).
Further In Situ EDXRD Studies of the MnO2 Cathode
Authors: Steingart Daniel A , Gallaway Joshua W , Hertzberg Benjamin Joseph , Erdonmez Can 
Published: February 2020

Alkaline Zn/MnO2 batteries employ low-cost, safe materials but typically target single-use applications due to irreversible phase transformations of electrode materials when recharged. We have developed shallow cycling protocols, limiting energy stored each cycle, but allowing hundreds of cycles of operation. This approach makes Zn/MnO2 a viable path for large scale grid-storage. We have used energy dispersive diffraction (EDXRD) to map crystalline phases and track their transformations in both fresh and extended shallow-cycled alkaline batteries. By comparing, in situ, phase content/distribution among batteries undergoing different cycling protocols, we have learn much empirically about degradation mechanisms and their dependence on cycling parameters. By comparing phase distributions in batteries aged to different cycle numbers, have determined more about the fundamental feasibility of shallow-cycled alkaline cells for grid applications and identify specific processes setting cycling life limits under current protocols.
The electrical grid has little storage, necessitating rigorous controls for continually matching electrical generationand demand. Intermittent generation sources (solar or wind power) will further amplify the need for grid-storage. Alkaline Zn-MnO2 cells are traditionally employed as primary batteries, as electrode materials develop stability problems upon recharge. The cathode material, MnO2 undergoes numerous phase transformations during discharge, some being irreversible. Reactions involving less than 0.5 electrons per Mn maintain the reversible MnO2 structure needed for recharging, but staying within this limit can be difficult in practice: rate distributions exist in commercially feasible, cm-scale cells. By shallow cycling, we have demonstrated the lifetimes of hundreds of cycles in alkaline batteries. Thus, overbuilding capacity and limiting rates within the battery may prolong Zn/MnO2 cell lifetime sufficiently for grid-storage. By studying in operando phase distributions and cycling-induced transformations in alkaline batteries, we can examine multiple failure modes within a real system simulatenously. Cells with extended cycling histories have been studied, revealing cumulative effects. We have also demonstrated that the EDXRD at X17B1 can spatially map, in situ, crystalline phases as a function of cycling parameters in a non-destructive way across many batteries in a single experiment, creating an application driven phase map.
We have observed the structural state of MnO2 is a strong function of not only state of charge, but cycling protocol, and we believe we have identified previously unseen "over strain" conditions in which one full electron is removed from a standard MnO2 electrode without the typical Mn2O3 "phase lock". The attached figure illustrates a time resolved EDXRD of MnO2 at the separator interface of a Duracell LR6 ("AA") Zn/MnO2 battery.
A Metal-Free Organic Aqueous Capacitor Using Quinonic Compounds Couple
Authors: Komatsu Daiki , Tomai Takaaki , Honma Itaru 
Published: February 2020

Redox-capacitors are electrochemical energy storage devices using the electric double layer capacity and pseudo-capacity derived from redox reactions. Because of its higher energy density than conventional electric double layer capacitors, higher power density than batteries and long cycle life, redox-capacitor is a promising candidate for grid-scale stationary energy storage device.
We demonstrated the aqueous redox-capacitors using inexpensive quinonic and hydroquinonic organic compounds as redox active materials, which facilitate charge/discharge by proton insertion/extraction in aqueous electrolyte. These quinonic/hydroquinonic compounds are supported in nanoporous carbon. This capacitor exhibited high energy density (＞20 Wh kg-1) and high power density (＞5 A g-1) without the degradation after 10000 charge/discharge cycles [Sci. Rep. 4, 3591 (2014).].
In this study, we investigated the dependence of loading rate of quinonic compound to carbon materials for further enhancement of energy density. It was found that quinonic compound, which is highly loaded in carbon (>70 wt%), can be utilized by adding a slight amount of carbon with high electrical conductivity. Finally, the high energy density of approximately 30 Wh kg-1 was achieved in the metal-free organic aqueous capacitor using quinonic compounds couple.
3D-Electrode Technology Platform for Energy Storage Safety
Authors: Prochazka Jan 
Published: February 2020

Thin film technology (2D) producing lithium ion accumulators has nearly been optimized. The capacity limits are given and the production cost is high. In addition, ultimate safety of this type of batteries cannot be provided.
It has been demonstrated that a significant increase of lithium battery capacity is feasible by removing organic binders and extending the electrode thickness from micrometers (2D) to millimeters (3D). This is allowed by a nanostructured morphology, which
The HE3DA®concept of several millimeters thick electrodes gives the battery incomparable safety and brings a number of new attributes, which are not achievable by the existing thin film technology.
3D electrodes provide a significant volumetric capacity increase. Recently developed internal cooling system, with electrolyte as the cooling media, radically shrinks the battery pack size and extends battery life. during operations,
The safe, robust construction with a multifunctional frame, easy degassing and possibility of electrolyte exchange and regeneration provides a new lithium accumulator technology platform ideal for large energy storage modules.
Autonomy and Battery Utilization within Microgrids and Solar-Battery Applications
Authors: Lawder Matthew T , Fenton Rachel K , Subramanian Venkat R. 
Published: February 2020

Distributed Energy Resources (DER) have increased penetration into the electric grid in recent years due to the growth of many renewable energy technologies as well as more efficient small conventional generation sources. Microgrids have grown in popularity along with the increased usage of DERs as a way to manage the multiple DERs on a local level.1Microgrids contain energy storage devices to store and distribute the intermittent energy provided by DERs (see figure 1).
Coupling a solar energy resource with a Li-ion battery energy storage, we study the autonomy (the percentage of time the system meets demand) and utilization (amount of capacity used) during yearly operation.2By including a demand schedule with the coupled solar and battery system, we study both how different demands, system sizes and solar insolation patterns will affect the autonomy and utilization of the system. Both islanded and grid-tied demand structures will be discussed.
The battery model involved in this study is an electrochemical and transport based Li-ion battery model.3For the solar portion of the model we will assess both ideal insolation curves as well as site based insolation data. For the real-site data, several solar monitoring sites within the US will be employed. The real data will offer a contrasting look at how much the coupled system can be affected on a daily and seasonal basis. In addition, using real data will allow for a greater assessment about the stability of a coupled system in areas with strong insolation, but high variability against areas of weaker insolation, but low variability. A balance between a high level of both autonomy and utilization will be studied in conjunction with preferable demand structures. This balance will affect the structure and operation of a microgrid with both solar and battery systems.

Acknowledgements

The authors acknowledge financial support from the U.S. Department of Energy’s Advanced Research Projects Agency- Energy (ARPA-E), and the Solar Energy Research Institute in India and the United States (SERIIUS), as well as, Washington University in St. Louis’ McDonnell Academy Global Energy and Environmental Partnership (MAGEEP).

References

1. R. H. Lasseter, Journal of Energy Engineering-Asce,
133, (2007)
2. C. Protogeropoulos, B. J. Brinkworth, and R. H. Marshall, International Journal of Energy Research,
21, (1997)
3. S. Santhanagopalan, Q. Z. Guo, P. Ramadass, and R. E. White, Journal of Power Sources,
156, (2006)
Invited Presentation: The Aprotic Lithium-Air Battery
Authors: Chen Yuhui , Freunberger Stefan A , Johnson Lee , Ottakam Thotiyl Muhammed , Liu Zheng , Peng Zhangquan , Bruce Peter G 
Published: February 2020

Li-ion and related battery technologies will be important for years to come. However, society needs energy storage that exceeds the capacity of Li-ion batteries. We must explore alternatives to Li-ion if we are to have any hope of meeting the long-term needs for energy storage. One such alternative is the Li-air(O2) battery; its theoretical specific energy exceeds that of Li-ion, but many hurdles face its realization.[1-5] First, we must understand the processes that occur in the cell on discharge and charge, then use such knowledge to address the hurdles.
A typical aprotic Li-O2 battery, shown in Figure 1, consists of a Li anode and a porous cathode, the two being separated by an organic electrolyte. On discharge, O2 from the atmosphere enters the porous cathode where it is reduced and is supposed to form Li2O2, which can be then be oxidised on charging.[1-5] Charge is stored in the cathode by reversible Li2O2 formation/decomposition. However, it is now understood that the reactive nature of reduced O2 species results in decomposition of many electrolytes and the cathode.[6-8]

Recent results on electrolyte and cathode stability will be discussed, with a particular focus on the instability of the ubiquitous carbon cathode.[9-10] By understanding these instabilities, it has been possible to demonstration that when using TiC as the positive electrode, sustained reversible Li2O2 formation/decomposition can be achieved, essential if the Li-O2 battery is ever to succeed.[11]

References
[1] P. G. Bruce, S. A. Freunberger, L. J. Hardwick, J.-M. Tarascon, Nat. Mater. 11 (2012) 19-29.
[2] J. Christensen, et al J. Electrochem. Soc. 159 (2012) R1-R30.
[3] G. Girishkumar, B. D. McCloskey, A. C. Luntz, S. Swanson, W. Wilcke, J. Phys. Chem. Lett. 1 (2010) 2193-2203.
[4] F. Li, T. Zhang and H. Zhou, Energy Environ. Sci., 2013, 6, 1125-1141.
[5] Y.-C. Lu, B. M. Gallant, D. G. Kwabi, J. R. Harding, R. R. Mitchell, M. S. Whittingham and Y. Shao-Horn, Energy Environ. Sci., 2013, 6, 750-768.
[6] F. Mizuno, S. Nakanishi, Y. Kotani, S. Yokoishi, H. Iba, Electrochemistry 78 (2010) 403-405.
[7] S. H. Oh, R. Black, E. Pomerantseva, J.-H. Lee, L. F. Nazar, Nat. Chem. 4 (2012) 1004-1010.
[8] V. S. Bryantsev, J. Uddin, V. Giordani, W. Walker, D. Addison and G. V. Chase, J. Electrochem. Soc., 2013, 160, A160-A171.
[9] B. D. McCloskey, A. Speidel, R. Scheffler, D. C. Miller, V. Viswanathan, J. S. Hummelshoj, J. K. Norskov, A. C. Luntz, J. Phys. Chem. Lett. 3 (2012) 997-1001.
[10] M. M. Ottakam Thotiyl, S. A. Freunberger, Z. Peng and P. G. Bruce, J. Am. Chem. Soc., 2012, 135, 494-500.
[11] M. M. Ottakam Thotiyl, S. A. Freunberger, Z. Peng, Y. Chen, Y. Liu and P. G. Bruce, Nat. Mater., 2013, 12, 1050-1056.
Invited Presentation: Si-based Anode -- Recent Development Status and Future Direction
Authors: Kang Sun-Ho , Kim Young-Ugk 
Published: February 2020

Due to its high theoretical capacity (ca. 4200 mAh/g), silicon has been regarded as one of the most promising anode materials for the next generation lithium ion batteries. However, silicon undergoes large volume changes (>300%) during lithium alloying and de-alloying processes leading to pulverization of the active material. Such mechanical failure results in loss of electrical contact with the current collector causing rapid decrease in capacity and consequent failure of the battery. Several approaches have been developed to address this problem, which involved use of nano-sized silicon particles [1], active/inactive matrices [2], amorphous silicon composites [3] and 1-dimensional nanostructures [4].
As a leading LIB provider, Samsung SDI is also very interested in the Si anode technology. In this presentation, Samsung SDI’s efforts for alleviating Si swelling and enhancing its cycle performance will be introduced.
Invited Presentation: Ionic Liquid Based Electrolytes for Li-Sulfur Batteries
Authors: Xiong Shizhao , Nitze Florian , Aguilera Luis , Palmqvist Anders , Matic Aleksandar 
Published: February 2020

Li-Sulfur (LiS) technology has great potential for large-scale energy storage applications due to the very high theoretical capacity. However, the implementation of the concept has been limited due to low sulphur utilization, severely decreasing the practical energy density, and poor cyclability in terms of fading capacity and rate capability. One major cause of these problems is the relatively large solubility of polysulfides (Li2Sn, n≥3) in the commonly used electrolyte systems. A direct consequence is the loss of active cathode material decreasing the capacity and at the same time increasing the resistance of the electrolyte. The dissolved polysulphides also cause degradation of the anode through shuttle reactions when they migrate in the electrolyte, forming insoluble layers on the anode surface.
The materials problems in the LiS battery can be addressed by new concepts for both the electrolyte and the cathode. For development of the electrolyte promising approaches include moving away from traditional organic solvents, improving both performance and safety. In addition the use of polymer gel-polymer, or solid-polymer, electrolytes or ceramic electrolytes has also been proposed to prevent, in particular, the shuttle reactions.
Ionic liquids have been highlighted as base for new and safe electrolytes [1]. Ionic liquids are low melting salts with intrinsic properties such as high ionic conductivity, low vapour pressure, and high thermal, chemical and electrochemical stability. Thus, they have the potential to both improve the performance and the safety of Li-ion and LiS-batteries. Ionic liquids can be used both to fully replace organic solvents as electrolyte solution or as co-solvents/additives improving both safety and performance. An ionic liquid-based electrolyte solution can also readily be incorporated in gel-type polymer membranes [2].
In this contribution we present new results on the use of ionic liquids as base for electrolytes in LiS-batteries. We have investigated systems based purely on ionic liquids, mixed electrolytes, where ionic liquids partially replace an organic solvent, and the recently proposed “solvated ionic liquids” [3]. In particular we focus on the dissolution and speciation of polysulfides in the electrolyte solution. One key issue is the role of polysulfides present in the electrolyte for the formation and stability of surface films on Li-anodes [4]. We also report results of the compatibility of the electrolytes with new nanostructured and functionalized sulphur carbon composite electrodes.
[1] A. Matic and B. Scrosati, MRS Bulletin38, 533 (2013)
[2] J. Pitawala, M. Assunta Navarra, B. Scrosati, P. Jacobsson and A. Matic
Journal of Power Sources, 245, 830-835 (2013)
[3] K. Ueno, K. Yoshida, M. Tsuchiya, N. Tachikawa, K. Dokko, and M. Watanabe, J. Phys. Chem. B 116, 11323 (2012)
[4] S. Xiong, K. Xie, E. Blomberg, P. Jacobsson, and Aleksandar Matic
Journal of Power Sources, 252, 150 (2014)