bluuebunny/crossref_metadata_2025_split huggingface dataset:
Wide Bandgap Copper Chalcopyrite Materials for Photoelectrochemical Hydrogen Production
Authors: Gaillard Nicolas 
Published: February 2020

Photoelectrochemistry (PEC) is one of the most efficient methods to produce alternative fuels, although the efficiency, cost, and durability of lab-scale systems are currently not at the level required to make this technology economically feasible. The chalcopyrite material class, typically identified by its most popular alloy Cu(In,Ga)Se2, provides exceptionally good candidates to meet the requirements identified for cheap, sustainable solar fuels production. As we recently reported[1], co-evaporated 1.6 eV CuGaSe2 offers very high-saturated photocurrent densities (-16 mA.cm-

2 in 0.5M H2SO4 under AM1.5G illumination), long durability (up to 400 hours), and high Faradaic efficiency (>85% for non-catalyzed systems). Although CuGaSe2 has the highest bandgap of the copper chalcopyrite class, its optical characteristics are still too close to that of amorphous silicon (a-Si), a low-cost material our research team has identified as an ideal photovoltaic driverin a monolithic hybrid photoelectrode device. Nevertheless, a solar-to-hydrogen efficiency of 3.7% was achieved using a co-planar integration scheme. In order to improve the water-splitting efficiency further, novel chalcopyrite alloys with bandgap greater than 1.6 eV must be developed.
In the present communication, we report on our efforts to synthesize 1.8-2.2 eV band-gap chalcopyrite materials for PEC water splitting. Specifically, we investigated the effect of sulfur on the optical and photoelectrochemical characteristics of the copper chalcopyrite material class. Using co-evaporated 1 μm-thick CuGaSe2 as baseline system, we demonstrate that the substitution of selenium with sulfur is accomplished through a simple annealing step. As a result, a dramatic change in optical properties was observed, with a bandgap increase from 1.6 eV (CuGaSe2) to 2.4 eV (CuGaS2), in good agreement with theoretical predictions[2]. Then, by simply adjusting the indium content in the film during the initial growth process, the bandgap of sulfurized copper chalcopyrite was decreased from 2.4 eV [GGI=Ga/(Ga+In)=1] to 2.2 eV (GGI»0.8) and finally to 2.0 eV (GGI»0.7). X-ray diffraction data indicated successful bulk sulfurization by the shift of the prominent (112), (220), and (312) reflections to higher angles. Preliminary PEC analyses revealed an anodic shift of the flatband potential with increasing bandgap when compared to CuGaSe2. This suggests that the bandgap modification in sulfurized films primarily stems from a downward shift of the valence band, an ideal situation for p-type PEC systems. Saturated photocurrent densities greater than -5 mA/cm2 were achieved with 2.0 eV red CuIn0.3Ga0.7S2 photocathodes in 0.5M H2SO4 under AM1.5G simulated illumination.

[1] N. Gaillard, D. Prasher, J. Kaneshiro, S. Mallory, and M. Chong, MRS Spring Meeting, Z2.07 (2013).
[2] M. Bär, W. Bohne, J. Rohrich, E. Strub et al., Appl. Phys. Lett. 96, 3857 (2004).
Invited: High Efficiency V/V Redox Flow Battery Stack Utilizing Mixed Acid Electrolyte Chemistry
Authors: Sprenkle Vincent , Reed David , Thomsen Ed , Wang Wei , Li Bin , Wei Xiaoliang , Nie Zimin , Kirby Brent , Murugesan Vijayakumar , Koeppel Brian J 
Published: February 2020

The demand for large-scale electrical energy storage (EES) devices has been growing for both improved efficiency and flexibility of the current grid infrastructure and to enable a higher penetration of stochastic renewable sources such like solar and wind onto the grid. Among the most promising technologies for the grid-scale EES are redox flow batteries (RFBs), which are capable of storing a large quantity of electricity (multi-MWs/MWhs) in a relatively simple and straightforward design. With support from the Department of Energy-Office of Electricity’s Energy Storage Program, PNNL developed a mixed-acid electrolyte (hydrochloric and sulfuric acid) for the all vanadium redox flow battery that offers significant improvements in thermal stability and solubility over the conventional, sulfate only system.
PNNL has incorporated the mixed acid electrolyte into kW scale systems in order to determine the optimal system efficiency at various flow, temperature, and current density conditions. A 15-cell stack utilizing Nafion® 115 was successfully operated at more 160 mA/cm2 over a 10 % - 90% SOC range with a stack energy efficiency of 74 %. At a flow rate of 6 lpm for both the catholyte and anolyte, the system obtained an overall efficiency (stack - pumping power) of 65%. With no active cooling the system reached a maximum temperature of 47°C. Replacing the 5 mil Nafion® 115 membrane with a 2 mil Nafion® 212, the energy efficiency increased to 79% while the operating temperature decreased to 43°C for the same 6 lpm flowrate. Further development was done on the catholyte and anolyte flow field to reduce the pressure drop through the stack. A new interdigitated flow field was designed and incorporated into the 15-cell stack. With the interdigitated flow field and the Nafion® 212 membrane, the stack efficiency remained at 79% but the system efficiency improved to 72% due to the lower pressure drop in the system. At 6 lpm flow rate, the interdigitated design resulted in ~ 3X decrease in the pressure drop across the cell (from an average of 6.5 psi to 2.5 psi for the interdigitated design). The operating temperature under these conditions was 40°C. Further testing of the interdigitated flow field and the Nafion® 212 membrane at 240mA/cm2 and the same electrolyte flow rate netted a stack energy efficiency of 71%, a system efficiency of 67%, and an operating temperature of 46°C.
Research and Development of Vanadium Flow Battery
Authors: Zhang Huamin 
Published: February 2020

Renewable energies from sources like solar and wind become the central topics of our times with the concerns of energy shortage and environment protection. However, the random nature of these intermittent renewable sources (change with synoptic conditions, day and night alternation, etc.) makes it quite challenging for its use and dispatch through the grid. One effective solution is to connect the power station and the grid with electrical energy storage devices.
Vanadium redox flow battery (VFB) as one kind of energy storage techniques is rather suitable for this application due to its features like long life time, active thermal management as well as the independence of energy and power ratings. Dalian Institute of Chemical and Physics has devoted to VFB research for more than 10 years from materials to system integration, where VFB stacks with power rating from 5 W to 31 kW were successfully developed. To further accelerate its commercialization, a spin-off company (Rongke power Co.Ltd) was established in 2008, where different demonstrations of VFB in different application field were carried out. In 2012, a world largest 5MW/10MWh VFB system was successfully integrated and combined with a 50 MW wind farm.
In this presentation, the development of VFB in DICP will be introduced and the performance of VFB systems will be discussed in detail.

References

1. Xianfeng Li, Huamin Zhang, Zhensheng Mai, Hongzhang Zhang, Ivo Vankelecom,
Energy & Environmental Science,

2011, 4 (4), 1147 – 1160

2. Cong Ding, Huamin Zhang, Xianfeng Li, Tao Liu, and Feng Xing,
J. Phys. Chem. Lett.

, 2013, 4 (8), pp 1281–1294
Invited Presentation: Research on Nano-Si/C Nanocomposites as Anode for Li-Ion Batteries
Authors: Luo Fei , Chu Geng , Li Hong , Chen Liquan , Huang Xuejie 
Published: February 2020

Nanosized silicon has been paid much attention as high capacity anode materials for Li-ion batteries since our first report in 1999. The main challenge for Si anode is the large volume variation during lithium insertion and extraction, which shows a linear dependence on the capacity. Several problems are caused consequently: 1) the total specific capacity of anode has to be limited due to fairly strict restriction on volume variation of batteries during operating, especially for tablet devices. Thus, the advantages of the high theoretical capacity and the volumetric energy density are not as significant as expected. 2) The solid electrolyte interphase (SEI) on the surface of silicon is not as stable as graphite and could be very thick, which consume lithium from cathode and nonaqueous electrolyte irreversibly, leading to low columbic efficiency, capacity fading, increase of internal resistance and gas release. 3) Nanosized silicon particles tend to agglomerate or merge into big pieces and follow further cracking, leading to the formation of the SEI on freshed surface and the loss of electronic contact for active particles. In order to solve above problems, great efforts have been paid and many strategies have been considered. Among them, SiOx, amorphous Si alloy and nano-Si/C composite are more promising for practical application in view of the electrochemical performances and cost.
In this report, we will summarize our investigation on the formation of very thick solid electrolyte interphase (SEI) on naked silicon anode at low rate, direct 3Dvisualization of multiple layer structured SEI. The optimization on additive, binder and microstructure for controlling interfacial properties and maintaining the structure stability of nano-Si/C composite anodes will be reported.
Acknowledgment: Financial support from CAS project (KJCX2-YW-W26), "Strategic Priority Research Program" of the Chinese Academy of Sciences,Grant No. XDA09010102 and National project 973 (2012CB932900) are appreciated.
Invited Presentation: Li-S Batteries and Beyond Systems: Electrochemistry and Materials Design
Authors: Guo Yu-Guo 
Published: February 2020

There is no doubt that the pursuit of advanced energy storage devices with higher energy densities is critical for powering our future society.[1,2] Among the best candidates for next-generation high-energy-storage systems, alkali metal-chalcogen batteries, including Li-S, Li-Se, and Na-S systems hold high theoretical energy densities, making them especially attractive. Here, we report the recent progress in this field starting from Li-S batteries. We discuss the electrochemistry of Li-S batteries with different sulfur allotropies,[3] the recent advances in S cathodes, Li anodes, electrolytes, as well as the new designs of Li-S pouch cells (5~10 Ah).[4] Secondly, we report advanced selenium-carbon cathodes for rechargeable Li-Se batteries, as well as the selenium molecules evolution upon cycling.[5] Finally, through employing the confined chain-like sulfur molecules as the active cathode component for room-temperature Na-S batteries, a novel mechanism is proposed and verified for the batteries’ electrochemistry, which bringing a tripled specific capacity and an increased specific energy compared to traditional high-temperature Na-S batteries.[6]

References

[1] Y.-G. Guo, J.-S. Hu, L.-J. Wan,
Adv.

Mater.

2008, 20, 2878
[2] S. Xin, Y.-G. Guo, L.-J. Wan,
Acc. Chem. Res. 2012, 45, 1759
[3] S. Xin, L. Gu, N. Zhao, Y. Yin, L. Zhou, Y.-G. Guo, L.-J. Wan,
J. Am. Chem. Soc. 2012, 134, 18510
[4] Y. X. Yin, S. Xin, Y.-G. Guo, L.-J. Wan,
Angew. Chem. Int. Edit. 2013, 52, 13186
[5] C.-P. Yang, S. Xin, Y.-X. Yin, H. Ye, J. Zhang, Y.-G. Guo,
Angew.

Chem. Int.

Edit.

2013, 52, 8363
[6] S. Xin, Y.-X. Yin, Y.-G. Guo, L.-J. Wan,
Adv. Mater.

2014, DOI: 10.1002/adma.201304126, in press
Invited Presentation: Non Lithium Based Technologies: Walking on the Sodium Side
Authors: Palacin M Rosa 
Published: February 2020

The development of room temperature sodium based batteries is currently a challenge in fundamental materials research. While it holds promise for accelerated development thanks to the knowledge gained in the “chemically similar” Li-ion ubiquitous technology, the Na-ion technology is still in its infancy. Proof of concept was given long ago1
,
2 but it is only recently that the topic has recaptured the attention of the scientific community concomitant to large scale development of the Li-ion technology and concerns about lithium cost and availability.3
,
4
,
5
Since Na-ion batteries do not involve the use of sodium metal anodes, there would be no a priori reason to think that they cannot attain the same performances than Li-ion if suitable positive and negative electrode materials are developed.
The talk will review recent research aiming at the development of negative electrode materials discussing analogies and differences between lithium and sodium systems.6,7,8 Results will also be presented dealing with systematic studies on electrolytes and formulation and assembly/performance of laboratory full Na-ion cells.9,10

References
[1] L.W. Shacklette, T.R. Jow, L. Townsend, J. Electrochem. Soc. 135 (1988) 2669.
[2] Y. Ma, M.M. Doeff, S.J. Visco, L.C. De Jonghe, J. Electrochem. Soc. 140 (1993) 2726–2733.
[3] V. Palomares, P. Serras, I. Villaluenga, K.B. Hueso, J. Carretero-González, T. Rojo, Energy Environ. Sci. 5 (2012) 5884.
[4] M.D. Slater, D. Kim, E. Lee, C.S. Johnson, Adv. Funct. Mater. 23 (2013) 947.
[5] S.W. Kim, D.H. Seo, X. Ma, G. Ceder, K. Kang, Adv. Energy Mater. 2 (2012) 710.
[6] P. Senguttuvan, G. Rouse, V. Seznec, J.M. Tarascon, M.R. Palacín, Chem. Mat. 23 (2011) 4109.
[7] A. Ponrouch, A.R. Goñi, M. R. Palacín. Electrochem. Comm. 27 (2013) 85.

[8] G. Rousse, M.E. Arroyo de Dompablo, P. Senguttuvan, A. Ponrouch, J.M. Tarascon, M.R. Palacín, Chem. Mat. 25 (2013) 4946.
[9] A. Ponrouch, E. Marchante, M. Courty, J.M. Tarascon, M.R. Palacín, Energy Environ. Sci. 5 (2012) 8572.
[10] A. Ponrouch, R. Dedryvère, D. Monti, A.E. Demet, J.M. Ateba Mba, L. Croguennec, C. Masquelier, P. Johansson, M.R. Palacín, Energy Environ. Sci. 6 (2013) 2361.
Invited Presentation: Microstructured Nanomaterials for Lithium-Ion Battery Anodes
Authors: Passerini Stefano , Bresser Dominic 
Published: February 2020

The tremendous success of lithium-ion batteries as power source for portable electronic devices since their first commercialization in 1991, marking a breakthrough in battery technology, has rendered them as the most promising energy storage devices for hybrid and, most likely, fully electric vehicles. However, further improvement in terms of energy and power density is still needed in order to meet the demands of modern society’s transportation requirements.
Particularly with respect to the anode side, recent research activities have shown the great benefit of nanostructuring the active material particles in order to combine high rate performance and large specific capacities for alternative anode materials, especially those undergoing rather large volume changes upon (de-)lithiation. However, nanosized particles suffer several safety, health, and processability issues.
We have recently proposed several composites of carbon and nanomaterials as alternative anodes in lithium-ion batteries. Several examples of micro-structured, insertion, alloying, and conversion-alloying nanomaterials will be presented, showing an enhanced performance compared to “simple” nanoparticles only.
Functionalized Graphene Cathode for High Energy and Power Na Rechargeable Batteries
Authors: Kim Haegyeom , Park Young-Uk , Park Kyu-Young , Lim Hee-Dae , Hong Jihyun , Kang Kisuk 
Published: February 2020

Developing low-cost and high-performance energy storage devices is important for sustainable energy utilization. Recently, sodium (Na) ion batteries have been highlighted as a possible competitor to lithium (Li) ion batteries because of their potential merit in the cost effectiveness. Na resources are earth-abundant, and Na electrochemistry shares many similarities with Li. However, their relatively low energy/power densities and unreliable cycle stability need to be addressed. In this work, we propose a novel high-performance cathode for Na rechargeable batteries based on functionalized graphene nanoplatelets. Starting from natural graphite, functionalized graphene nanoplatelets were fabricated via simple scalable routes, which could control the chemical composition and porous nanostructure of the sample in one-step. By using surface reactions between Na and functionals on graphene nanoplatelets, (i) no significant lattice change occurred during battery cycling, and (ii) much faster Na kinetics could be achieved through porous network without solid-state diffusion.[1] Furthermore, the high electrical conductivity of the material could aid in improving the rate capability.[2] While previous studies of graphite-based electrodes are mostly found in anode applications for NIB and only very recently its cathode application was discovered, [3, 4] this work manipulated the carbon into a cathode with a tunability of composition and nanostructure by simple one-step chemical modification. The functionalized graphene cathode could deliver the energy of ~500 Wh kg-1 without capacity decay during 300 battery cycles and could also exhibit an unprecedentedly high power of ~55 kW kg-1with a less-than-10 s charge/discharge rate for NIB.

References

[1] H. Kim, H.-D. Lim, S.-W. Kim, J. Hong, D.-H. Seo, D.-c. Kim, S. Jeon, S. Park, K. Kang, Sci. Rep., Scalable Functionalized Graphene Nano-platelets as Tunable Cathodes for High-performance Lithium Rechargeable Batteries 3 (2013) 1506.
[2] S.-M. Oh, S.-T. Myung, J. Hassoun, B. Scrosati, Y.-K. Sun, Electrochem. Commun., Reversible NaFePO4electrode for sodium secondary batteries 22 (2012) 149-152.
[3] Y.-X. Wang, S.-L. Chou, H.-K. Liu, S.-X. Dou, Carbon, Reduced graphene oxide with superior cycling stability and rate capability for sodium storage 57 (2013) 202-208.
[4] Z. Wang, L. Qie, L. Yuan, W. Zhang, X. Hu, Y. Huang, Carbon, Functionalized N-doped interconnected carbon nanofibers as an anode material for sodium-ion storage with excellent performance 55 (2013) 328-334.
Binder-Free Thick-Film Anodes of Si Coated with Rutile-Type TiO2
Authors: Usui Hiroyuki , Wasada Kuniaki , Shimizu Masahiro , Sakaguchi Hiroki 
Published: February 2020

As an anode material for high-performance Li-ion battery, we have synthesized composites of rutile-type TiO2 and Si by a facile sol-gel method because we focus that a fast Li-ion diffusion in TiO2 can improve a slow kinetics of Li-ion transfer in Si anode. We have investigated anode performance of binder-free thick-film electrodes prepared by a gas-deposition method using the TiO2/Si composites obtained. This method has a unique advantage: essential electrochemical reactions of only active materials can be evaluated because the thick-film electrodes do not include any binder and conductive additive.
Electrode performance as Li-ion battery anode was evaluated in beaker-type there-electrode cells using the TiO2/Si electrodes as working electrodes and Li sheets as counter and reference electrodes. The electrolyte was LiClO4dissolved in propylene carbonate at a concentration of 1 M. Galvanostatic charge–discharge tests were carried out using an electrochemical measurement system at 303K.
X-ray diffraction analysis and field-emission scanning electron microscopic observations revealed that the Si surface of the composites was uniformly covered by rutile TiO2 nanoparticles with 10–50 nm in size. Charge–discharge curves were measured for the TiO2/Si composite electrodes with weight ratios of 43/57 wt.% and 66/34 wt.%. For every electrode, we clearly observed potential plateaus in the charge (lithiation) and discharge (delithiation) processes at 0.05 V and 0.45 V vs. Li/Li+ at the first cycles. These potential plateaus are attributed to the alloying/dealloying reactions of Li–Si. After the second cycles, the charge plateaus inclined and rose to 0.1–0.2 V vs. Li/Li+, which has been explained as resulting from amorphization of Si at the first cycle and its single-phase reaction with Li+in the subsequent cycles. The electrodes behaved very alike until the 100th cycle.
Figure 1 shows cycling performances of the TiO2/Si composite electrodes. The initial discharge capacities of 1500 and 790 mA h g−1 were obtained for the TiO2/Si electrodes of 43/57 wt.% and 66/34 wt.%. These capacities correspond to capacities per Si of 2500 and 2100 mA h g(Si)−1. The composite electrode of TiO2/Si (43/57 wt.%) exhibited a remarkably improved cyclability at a current rate of 1.6C: the discharge capacity of 710 mA h g−1 (1170 mA h g(Si)−1) could be achieved even at the 900th cycle. In addition, the electrode showed a specific capacity per Si weight was as large as 1870 mA h g(Si)−1 even at a high current rate of 4.8C, whereas an Si electrode showed the comparable capacity at a low rate of 1.6C. It is considered that a fast Li-ion diffusion in TiO2 provides smooth insertion/extraction of Li-ion into/from the composite electrodes. The results offer a utility of rutile TiO2 as a Li-ion conductor in Si-based electrodes for the next-generation Li-ion battery.
Recent Progress for Room-Temperature Stationary Sodium-Ion Batteries
Authors: Hu Yong-Sheng 
Published: February 2020

In the energy storage field, lithium-ion batteries have been extensively explored as power sources for various types of important applications, such as portable electronic devices, electrical vehicles, etc. Due to the low abundance of lithium in the Earth’s crust (0.0065%), large-scale applications of lithium-ion batteries become questionable, especially if low cost and high efficient recycling technology could not be developed. Alternatively, room-temperature sodium-ion batteries, which were originally investigated in parallel with lithium-ion batteries, have again aroused interest particularly as stationary batteries for large-scale electrical energy storage in the applications of renewable energy and smart grid owing to a large abundance (2.75%) of sodium resources and potentially low cost, for which the demanding on energy densities of the power sources is not so seriously.
In this contribution, I will present our recent work on several cathode and anode materials including Na3V2(PO4)3/C [1,2], Li3[LiTi5]O12 [3,4,5], zero-strain P2-Na0.66[Li0.22Ti0.78]O2 [6], Na2Ti3O7 [7], Na2C8H4O4 [8] and hard carbon sphere (HCS) [9] as well as a new electrolyte system for room-temperature stationary sodium-ion batteries [10]. Several full cells based on our developed cathode and anode materials will also be demonstrated.

References

[1] Z. L. Jian, L. Zhao, H. L. Pan, Y.-S. Hu, H. Li, W. Chen, L. Q. Chen,
Electrochem. Commun
., 2012, 14, 86-89.
[2] Z. L. Jian, W. Z. Han, X. Lu, H. X. Yang, Y.-S. Hu, J. Zhou, Z. B. Zhou, J. Q. Li, W. Chen, D. F. Chen, L. Q. Chen,
Adv. Energy Mater.
, 2013, 3, 156-160.
[3] L. Zhao, H. L. Pan, Y.-S. Hu, H. Li, L. Q. Chen,
Chin. Phys. B
, 2012, 21, 028201.
[4] Y. Sun, L. Zhao, H. L. Pan, X. Lu, L. Gu, Y.-S. Hu, H. Li, M. Armand, Y. Ikuhara, L. Q. Chen, X. J. Huang,
Nature Communications
, 2013, 4, 1870.
[5] X. Q. Yu, H. L. Pan, W. Wan, C. Ma, J. M. Bai, Q. P. Meng, S. N. Ehrlich, Y.-S. Hu, X.-Q. Yang,
Nano Lett
., 2013, 13, 4721.
[6] Y. S. Wang, X. Q. Yu, S. Y. Xu, J. M. Bai, R. J. Xiao, Y.-S. Hu, H. Li, X.-Q. Yang, L. Q. Chen, X. J. Huang,
Nature Communications
, 2013, 4, 2365.
[7] H. L. Pan, X. Lu, X. Q. Yu, Y.-S. Hu, H, Li, X.-Q. Yang, L. Q. Chen,
Adv. Energy Mater
., 2013, 3, 1186-1194.
[8] L. Zhao, J. M. Zhao, Y.-S. Hu, H. Li, Z. B. Zhou, M. Armand, L. Q. Chen,
Adv. Energy Mater
., 2012, 2, 962-965.
[9] J. Z. Yu, Y. S. Wang, H. L. Pan, L. Zhao, Y.-S. Hu, H. Li, L. Q. Chen, in preparation.
[10] H. L. Pan, Y.-S. Hu, L. Q. Chen,
Energy Environ. Sci
., 2013, 6, 2338-2360.

Figure 1
Typical discharge/charge curves of the proposed materials for room-temperature sodium-ion batteries