bluuebunny/crossref_metadata_2025_split huggingface dataset:
Vanadium Based Full Water Splitting Electrocatalysts
Authors: Saxena Apurv , Masud Jahangir , Nath Manashi 
Published: February 2020

Recently, alternative energy research has focused on attempting to produce hydrogen efficiently by splitting water in an electrochemical and photoelectrochemical process. However, the efficiency of water splitting reaction is limited by the challenging anodic oxygen evolution reaction (OER), which is an energy-exhaustive 4 electron process, leading to a kinetically slow step and significant efficiency loss. Thus, an efficient electrocatalyst is required to enhance the OER process. The most active and stable electrocatalysts are based on precious metals like ruthenium and iridium in dimensionally stable anodes working in harsh environments which limits their application to industrial processes. A tremendous development has been obtained in the water-splitting research using transition metal chalcogenides-based nanomaterials. Here, we demonstrate vanadium selenide (V1.04Se2) electrocatalysts for oxygen evolution reaction (OER) in alkaline solution.
The catalyst was synthesized hydrothermally using vanadium pentaoxide and selenium dioxide. The synthesized vanadium selenide was characterized by XRD, XPS, SEM, TEM, and EDS for morphology, elemental chemical compositions, particle distribution. The OER catalytic activity and stability was performed in 1M KOH solution. The vanadium selenide required only 270 mV overpotential to achieve the 50mA cm-2 OER current and with a low Tafel slope value. It showed excellent stability under continuous oxygen generation condition for an extended period. The details of catalyst synthesis, characterization and activity will be presented in the meeting.
Development of Supported Iridium Oxides As the Low Noble Metal Loading Anode for PEM Water Electrolyser
Authors: Shi Yan , Lu Zhuoxin , Tan Hongyi , Guo Changqing , Wang Zhida , Yan Changfeng 
Published: February 2020

Reducing the cost of PEM water electrolyser is still a big challenge for renewable energy storage. Though there are some reports which have achieved very low Ir loading (0.1~0.2mg/cm2) in membrane electrode assemblies (MEA) for PEM water electrolyser, the other issues such as the performance and stability of MEA, the reduction of Pt loading in cathode and the scalability of preparation method of MEA still need further investigation for developing low cost and high performance PEM water electrolyser.
In this work, to develop high performance anode with low Ir loading, highly active Iridium oxohydroxides were supported on conductive titanium metal nanosphere as the anode catalyst. The diatmeter of metal Ti nanosphere ranges from 60-200nm, and the Iridium oxohydroxides loaded on Ti support shows a particle size between 1.5-3nm. The OER activity of the catalyst with various Ir loading was characterized, and the catalyst with 10% Ir loading exhibited highest Ir mass activity (1700A/g @η=0.37V), it is about 6 times as the commercial IrO2. Increasing the loading of Ir will lead to the decline of Ir mass activity, this may be due to the limited surface area of Ti nanosphere. The stability of the catalyst (Ir loading 10%) was characterized by CV scans between 0.4-1.5V (vs.RHE) in 0.5M H2SO4. After 2000 cycles, the active sites of IrOx declined only 18%, and the catalyst does not show an obviously rising in resistance from EIS characterization, indicating a good stability both on active sites and support.
The MEAs using such IrOx/Ti as the anode were prepared by conventional CCM method, and the Pt loading (20% wt. Pt/C) in cathode was reduced to about 0.2mg/cm2. The anode with various Ir loading and membrane with different thickness were determined at atmosphere under 80 degrees. The electrolyser with Ir loading 0.13mg/cm2 in anode, Pt loading 0.18mg/cm2 in cathode and N212 membrane achieved 1.623V at 1A/cm2 and 1.778V at 2A/cm2, which exhibits a good performance with such low noble metal loading. Further decreasing the Ir loading in anode catalyst layer will lead to performance degradation, but the rising of voltage was only 50-60mv at 1A/cm2 when Ir was reduced to 0.08 mg/cm2. With respect of the durability of MEAs, an electrolyser using Nafion 117 as the membrane, and 0.08 mg /cm2 Ir in MEA was tested under 1A/cm2. After 850h, the voltage increased from 1.79V to 1.83V, and the degradation rate is below 50μV/h, this suggests a good stability of supported Iridium oxohydroxides, and the stability of electrolyser with N212 membrane is now ongoing.

Figure 1
Electronic Properties of the Co3O4 Photoelectrode: Predictions from First-Principles Calculations
Authors: Pham Tuan Anh , Smart Tyler , Ping Yuan , Ogitsu Tadashi 
Published: February 2020

Cobalt Oxide (Co3O4) has emerged as a highly promising material for hydrogen generation through photoelectrochemical cells (PECs); however, a detailed understanding of the electronic properties of this material is largely lacking. This includes the band gap and electrical conductivity of the photoelectrode, which are important factors in determining the performance of PECs. For example, contradicting experimental results have been reported for the optical gap of Co3O4, leading to two commonly reported values of 0.8 eV and 1.6 eV. In this work, we have employed first-principles calculations based on Density Functional Theory to support that the intrinsic band gap of Co3O4 is 1.6 eV. Meanwhile, we show that the 0.8 eV transition found experimentally is due to the presence of polaron or defect states. In particular, our calculations predict the spontaneous formation of electron and hole polarons, that in turn exhibit significant contribution to the absorption spectra of the material, and are responsible for the optical excitation at 0.8 eV. Finally, we resolve the nature of the stable spin states of electron and hole polarons, and we discuss how the interaction between polarons with n-type dopants, such as carbon, could improve the electrical conductivity of this intrinsic p-type material.
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
(Invited) Development and Practical Verification of the Redox Flow Battery in SEI
Authors: Shigematsu Toshio 
Published: February 2020

More than 40 years have passed since the basic principle of the Redox Flow Battery (RFB) was proposed by NASA. Currently, with the widespread use of renewable energy, demand for energy storage batteries is increasing more and more. MW class RFBs are already in practical use in electric power systems. On the other hand, further improvement of performance and cost reduction are urgent issues for mass introduction of RFBs. A wide variety of research and development activities are being conducted all over the world.
The development of RFBs in Japan began with AIST, a national laboratory aimed at the load-leveling of electric power companies in the 1970s. SEI began development as a collaborative research project with a power company in 1985 and has been developing first the Fe/Cr RFB followed by the V/V RFB for commercialization. Along with changes in the situation of the power industry for many years, SEI has delivered about 30 RFBs from large batteries to small ones according to customer's request.
In particular, since the establishment of the FIT system in Japan in 2012, a large amount of PV systems has been introduced and the need for energy storage batteries is rapidly rising. With the support of METI (the Ministry of Economy, Trade and Industry), a 15 MW RFB was installed in 2015 and is currently operated by Hokkaido Electric Power Company.
In this presentation I will introduce the power situation and the necessity of energy storage in Japan, the history of RFB development in SEI, and the operation experience of some systems. SEI is also developing a new electrolyte technology using titanium and manganese ions, which is one of our latest developments aimed at cost reduction. I would like to introduce these developments as well.
References
[1] T. Shigematsu, SEI Technical Review, 73, 4(2011)
[2] Y. R. Dong, et.al., ECS Trans., 69 (18), 59 (2015)
[3] H. Kaku, et.al., ECS Trans., 72 (10), 1 (2016)
Effect of Sodium Fluoride and Sodium Lignosulphonate Additives on Performance of the Soluble Lead Redox Flow Battery
Authors: Suman Rathod , Ravikumar Musuwathi Krishnamoorthy , Jaiswal Nandini , Patil Satish , Shukla Ashok Kumar 
Published: February 2020

Soluble lead redox flow battery (SLRFB) is a flow battery with a common electrolyte and can be developed in undivided, divided and semi-divided configurations [1]. At present, the development of SLRFB is hindered mainly due to (i) the formation of lead dendrites at anode, (ii) oxygen evolution reaction (OER) at cathode and (iii) accumulation of PbO2 due to poor electrode kinetics [2]. In an earlier study, we have reported a study on extending the cycle-life of SLRFB using an auxiliary electrode concept [3]. In the present study, we report the independent and combined effects of adding sodium lignosulfonate (SLS) and sodium fluoride (NaF) to the electrolyte as anode and cathode benefitting additives, respectively. The study reveals that adding 4.2 gm/L NaF alone improves the kinetics of both electrode reactions as compared to that with no additive but fails to prevent dendrite formation. Adding 1 gm/L SLS alone has beneficial effect on anode by preventing dendrite formation but the concentration of SLS gradually decreases with the cycling of the battery. The combined effect of adding SLS and NaF depends on the concentration of SLS. It is observed that adding low concentration of SLS 0.2 gm/L along with 4.2 gm/L NaF has beneficial effect on both the anode and cathode reactions and hence maintaining this concentration would help extending the cycle-life of SLRFB. The individual as well as combined effects of these additives on the reaction products is studied by quasi in situ XRD and FESEM techniques. The effect on electrode kinetics and cycle life are also reported.

References

1. M. Krishna, R.G.A. Wills, A.A. Sha, D. Hall and J. Collins, J. Appl. Electrochem.,
48(9) 1031 (2018)
2. D. Pletcher, ECS Transactions,
28(16) 1 (2010)
3. R. Suman, M.K. Ravikumar, N. Jaiswal, S. Patil and A.K. Shukla, ECS Meeting 233, Abstract no. MA2018-01, 221 (2018)

Acknowledgements

Financial support from UKRI Global Challenge Research Fund project, SUNRISE (EP/P032591/1) and DST, New Delhi is gratefully acknowledged.

Figure 1
Optimally Engineered Flow-through Electrodes Using Automatic Design Algorithms and Additive Manufacturing
Authors: Beck Victor A , Weisgraber Todd H , Ivanovskaya Anna N , Chandrasekaran Swetha , Moran Bryan D , Watts Seth E , Tortorelli Dan A , Duoss Eric B , Biener Juergen , Stadermann Michael , Worsley Marcus A. 
Published: February 2020

Flow batteries are a promising technology for large scale energy storage and load balancing from intermittent power sources, but their viability hinges on our ability to attain high-power outputs while minimizing costs and meeting performance constraints. Controlling fluid flow, active species distribution, and mass transport in the electrode has a dramatic impact on cell power and efficiency. However, this control is often limited to changing a quasi-two-dimensional flow field and selecting bulk properties of a monolithic electrode. This can lead to non-uniform reaction rates, underutilized regions of the flow cell, and can limit the ultimate performance of the devices. We propose an alternative approach which seeks to control the fluid distribution in the cell by controlling the electrode geometry. Our approach is enabled by additive manufacturing techniques which allow us to directly build three-dimensional morphologies. Further, to determine effective electrode geometries, we employ topology optimization techniques that couple solution of the forward electrochemical problem over the full electrode domain with gradient-based optimization. The output of our code is a three-dimensional CAD representation which optimizes over specific performance metrics and which can be used to print functional electrodes. We will demonstrate the process for generating the electrodes using our optimization framework and present experiments comparing the performance of the optimized geometries across designs and against conventional electrodes. This work provides a systematic path toward automatic design of engineered electrodes with precise control over the fluid and species distribution.
LLNL-ABS-764035
This work was performed under the auspices of the U.S. Department of Energy by Lawrence Livermore National Laboratory under Contract DE-AC52-07NA27344.
(Invited) RKP Vanadium Flow Battery and its Application
Authors: Ma Xiangkun , Zhang Huamin , Xu Xiaobo , Jiang Shan , Wu Jingbo , Chigan Ting , Wang Hongbo , Zhao Haijun , Chen Ning 
Published: February 2020

Vanadium flow battery(VFB) is deemed to be one of the most promising technologies for large-scale industrial energy storage, due to its attractive features like flexible capacity, active thermal management, long cycle life and high safety. Dalian Rongke Power Co., Ltd. (RKP) has been devoted to the fundmental study and advanced research of Vanadium flow battery applications. It has become one of the world-leading enterprises in VFB development, manufacturing and delivery industry. The products have evolved from earlier indoor structure to the latest containerized system designs. More than a dozen VRFB systems have been deployed and end products have been launched into operations across the world over the past decades.
The 500kW/2MWh VFB product was developed for the large scale energy application, which is consisted of 16 cell stacks. The high integration level, low shunt current loss, low auxiliary power supply consumption and high reliability were achieved. The novel cell stack is designed by optimizing the key materials and cell stack structure, which can achieve a better performance and higher reliability at a relatively low cost. The energy efficiency(EE) could reach 80% at the rated power of 33kW, and the current density could be improved to 140~150 mA/cm2.The cycle life test indicated that no obvious performance decay was found even after 10000 cycles. The advanced two-stage power conversion system (PCS) was selected in order to realiaze the independent control of each sub-systems, which would improve the overall reliability ultimately. The AC/AC energy efficiency could reach 70% at the rated power of 500kW. The 500kW/2MWh VFB product has been installed in power plants for wind and solar energy storage and has obtained better application effect.
The world largest battery system, a 200MW/800MWh VFB peaking power plant conducted by RKP, is currently in progress in Dalian, China. The purpose is to improve the Northeast grid resiliency and facilitate smooth integration of renewables. A 500kW/2MWh VFB product is the minimum storage unit of the project. Each unit product could be controled independently. The foreseeable success of the project would exert great influence on the development of the flow battery in the future.
In this presentation, new technolgy and product developments of vanadium flow battery at RKP will be introduced and further challenges will be addressed as well.
Iron(tris pyridyl-imine) Complexes As Redox Couples for Non-Aqueous Redox Flow Battery Applications
Authors: Maurya Sandip , Smythe Nathan , Davis Benjamin L , Andrade Gabriel , Sharma Shikha , Park Eun Joo , Gordon John , Kim Yu Seung , Mukundan Rangachary 
Published: February 2020

Grid-scale energy storage technologies are much needed for efficient integration of intermittent energy sources, such as wind and solar, into the electrical grid. Redox flow batteries (RFBs) have decoupled power and stored energy qualities, in contrast to traditional batteries, storing energy chemically in scalable solutions, and thus have the potential to solve the large-scale energy storage issue. Conventional redox flow chemistries are aqueous-based, such as Iron-chrome and all vanadium, where operating cell voltages are limited by water splitting reactions. Therefore, non-aqueous RFBs, which can operate at much higher voltages, are gaining attention and are typically only limited by the potential window of the non-aqueous solvent. Despite having enlarged potential windows that could provide higher energy density, most of the non-aqueous RFBs still operate at very low concentration, current densities and suffer from poor cycle life. In addition, the high cost of metals, such as vanadium, ruthenium, cobalt, etc., are an obstacle to achieving the DOE’s long term target of 150 USD per kWh for RFBs.
In this presentation, therefore, we will discuss the synthesis and characterization of iron pyridine-imine complexes for redox couples. The performance of these redox couples in a bulk electrolysis cell and flow battery set-up will also be discussed. A mechanistic study to understand the fundamental degradation mechanisms of the redox couples under continuous charge/discharge operations will also be discussed. Our results indicate that iron complexes possess good reversibility and have the potential to compete, and potentially replace, other redox systems used in non-aqueous RFBs.

Acknowledgement

This work is supported by the Laboratory Directed Research & Development Program at Los Alamos National Laboratory.
Mechanically Robust Crosslinked Membranes for Non-Aqueous Redox Flow Batteries
Authors: Lehmann Michelle , Yang Guang , Self Ethan Craig , Li Bingrui , Delnick Frank M. , Nanda Jagjit , Saito Tomonori 
Published: February 2020

Non-aqueous redox flow batteries (RFBs) are potential alternatives to aqueous redox flow systems for large scale energy storage. The advantages of non-aqueous RFB’s over aqueous systems are a larger voltage operating window, wider temperature range and the potential for increased energy density. A sodium-based system is of interest due to sodium’s low cost and natural abundance. One major challenge for non-aqueous RFB’s is the lack of high performance membranes that can withstand their operation conditions. A membrane for an RFB needs to possess sufficient mechanical strength, high conductivity, ion selectivity and excellent chemical resistance. In this project, mechanically robust, chemically resistant, crosslinked membranes have been fabricated via thermal or UV curing. In one system, crosslinked poly(ethylene oxide)-based membranes containing 10 wt% to 40 wt% sodium triflate have been studied as dry and plasticized samples. Careful tailoring of the crosslinking chemistry allows the membranes to be free standing, flexible and robust with and without plasticizer. The membranes are stable over a wide temperature range, with a constant storage modulus of ~1 MPa from -20 °C to 180 °C even with the addition of plasticizer. The mechanical strength of the membranes is enhanced by 3 orders of magnitude to above 1 GPa with the addition of an inorganic filler, without any significant adverse effect on ionic conductivity. Specific ionic conductivities up to 2.0 x 10-4 S/cm at 20 °C and 7.1 x 10-4 S/cm at 70 °C are achieved for the plasticized membrane, while ionic conductivities for the dry membrane are 3.0 x 10 -6 S/cm at 20°C and 6.4 x 10-5 S/cm at 70 °C. Furthermore, our efforts on the synthesis and characterization of sodium sulfonate functionalized cation exchange membranes will be discussed.
This work is funded by Dr. Imre Gyuk, Office of Electricity Delivery and Reliability, Department of Energy and the Laboratory Directed Research and Development Program of Oak Ridge National Laboratory, managed by UT-Battelle, LLC.”
Effect of Surfactant for PTFE Binder Dispersion of Electrodes Prepared By Bar Coating Method in High Temperature Polymer Electrolyte Membrane Fuel Cell
Authors: Lee Min Jae , Lee Ju Sung , Lee So Young , Kim Hyoung-Juhn , Song Kwang Ho 
Published: February 2020

Polymer electrolyte membrane fuel cells (PEMFCs) are one of the most promising energy devices for both mobile and stationary applications due to their high energy conversion efficiency and low environment pollution. However, there are some problems to be solved. PEMFCs operating at low temperatures (below 80℃) based on Nafion require humidification and have low CO tolerance. To overcome this problem, high-temperature PEMFCs that operate up to 180℃ are being studied. High temperature PEMFCs does not require humidification, which simplifies the system and is highly resistant to CO. It also has the advantage of using waste heat. However, the cell performance of high-temperature PEMFCs is still much lower than that of low-temperature PEMFCs and needs to be increased for practical applications
The reason for this is slow Oxygen Reduction Reaction (ORR) and limited transport of protons and reactants, especially in the presence of phosphoric acid in the catalyst layer. In the high-temperature PEMFCs, phosphoric acid acts as a proton conduction as an electrolyte and is a necessary element for electrochemical reactions at the triple phase boundaries. Therefore, if the amount of phosphoric acid in the catalyst layer is too small, it exhibits low electrochemical activity. If it is too much, the pore inside the catalyst layer is blocked to restrict the movement of the fuel, thereby reducing the number of triple phase boundaries and reducing the performance. Therefore, the amount and distribution of phosphoric acid and the formation of structural network pores in the catalyst layer are important. Thus, several polymeric binders have been introduced to perform this role. Among them, PTFE is known as the most promising binder. PTFE has hydrophobicity and high chemical stability. However, PTFE easily agglomerates and sinks immediately in the solvent due to its high hydrophobicity. Therefore, if an electrode is made of a catalyst slurry that does not properly disperse PTFE, uniform PTFE distribution in the catalyst layer cannot be expected. So, in the catalyst layer, there may be more or less parts of the specific part than the desired PTFE content. Therefore, it is not only difficult to form a proper phosphoric acid distribution and structural network of the catalyst layer, but also may affect the reproducibility of electrode manufacturing.
In this study, the catalytic electrode was prepared by introducing a surfactant to disperse PTFE in the preparation of catalyst slurry. Single cell test was carried out using membrane electrode assembly made from this electrode. And the electrochemical and structural characterizations were compared. The details will be discussed in presentation.