bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Plenary) Solid State Li-Ion Batteries: Material Advances and a Reality Check
Authors: Nazar Linda F , Kaup Kavish , Zhou Laidong , Zhang Zhizhen , Park Kern Ho 
Published: February 2020

The development of safe and high-performance all-solid-state batteries (ASSB) is contingent on creating fast ion conductors that combine high ionic conductivity with good ductility and chemical stability in a large voltage window, while – especially - mastering the interface of the solid electrolyte with the electrode materials. This presentation will examine ways to address these factors with new materials, while also shedding light on design concepts for ion conductivity.
The talk will cover an overview of the state-of-the art in the field, followed by a focus on recent findings in our laboratory concerning a) synthesis of thiophosphate-halide argyrodites, where very significant increases in conductivity above that of the parent Li6PS5Cl phase have been attained by both tuning composition and developing “clean” solution-engineering processing routes to these materials; b) creation of novel thiophosphate-halide and related structures that exhibit both ion conductivities above 1 mS/cm and good chemical stability; c) understanding the critical role that the anion framework plays in dictating ion conductivity using a combination of room/high temperature X-ray/neutron diffraction, NMR, and ab initio molecular dynamics simulations; d) examination of the interface of the solid state electrolytes at the positive and negative electrodes in practical ASSBs.
(Invited) Exploring the Impact of Mechanical Pressure on the Performance of Anode-Free Lithium Metal Cells
Authors: Louli Alexander J , Genovese Matthew , Weber Rochelle , Dahn Jeff R 
Published: February 2020

Research on lithium metal batteries has made a resurgence in the quest to surpass the energy density of conventional lithium ion batteries. Many reports in the literature utilize Li-metal cells with significant excess lithium, thereby artificially inflating the cycling efficiency and cycle life of such cells since lost lithium inventory can be replaced from a vast reservoir. However, utilizing significant excess lithium can drastically reduce the energy density of Li-metal cells even below that of conventional Li-ion as shown in Figure 1; at 200% excess lithium, the theoretical volumetric capacity of Li of 2060 mAh/L becomes 687 mAh/L, lower than the volumetric capacity of graphite of 719 mAh/L. Clearly cells with significant excess lithium are not poised to succeed conventional lithium ion cells in delivering superior energy density. In contrast, anode-free cells do not utilize excess lithium and thus can deliver the maximum theoretical capacity of lithium metal. In an anode-free cell, the lithium ions stored in the positive electrode plate on a bare current collector during the first charge to form a lithium metal anode in-situ.1,2 As such, lithium metal is not required during the construction of anode-free cells, resulting in a cheaper, safer and more practical Li-metal cell.
In this work, we evaluate anode-free Li-metal pouch cells (NMC532||Cu) with operando pressure measurements constrained to different stack pressures between 75-2205 kPa with two different electrolytes, 1M LiPF6 fluoroethylene carbonate: diethyl carbonate (FEC:DEC 1:2) and 1M LiPF6 fluoroethylene carbonate:bis(2,2,2-trifluoroethyl) carbonate (FEC:TFEC 1:2). Increasing the initial average pressure from 75 to 2205 kPa was found to generally improve cycling performance, with the most significant benefits achieved up to 1205 kPa. Cells containing FEC:TFEC electrolyte exhibited a superior initial plating efficiency than FEC:DEC cells. The benefit of constraining cells containing FEC:TFEC electrolyte is shown in Figure 1. Although generally beneficial, we found that the effect of increased pressure on the performance of cells with different solvent systems was not equal, particularly at high pressures, indicating that the physical properties of the electrolyte play an important role in cells constrained to higher pressures between 1205 and 2205 kPa. This work presents anode-free cells which deliver a larger energy density than conventional Li-ion cells for 50 cycles.

Figure 1
Plane-Selective Coating of LiCoO2 Powders for Li-Ion Batteries
Authors: Kim Hanseul , Lee Kyu Tae 
Published: February 2020

LiCoO2 is one of the most widely commercialized cathode materials for Li-ion batteries. Recently, LiCoO2 has been revisited to improve its reversible capacity by increasing the upper cut-off voltage to 4.55 V (vs. Li/Li+). However, LiCoO2 suffers from determental Co-dissolution and electrolyte decomposition at high voltages and high temperatures, resulting in poor electrochemical performance.[1,2] In this connection, various coated LiCoO2 powders have been investigated to reduce these irreversible surface reactions.[3]
Coated LiCoO2 powders are usually obtained via sol-gel synthesis, dry coating, and atomic layer deposition. These coating techniques are pursuing to uniform coating covering the whole surface of LiCoO2 powders. However, the full coverage of coating layers interrupts the charge-transfer of Li+ ions, resulting in the poor rate capability of LiCoO2. This implies that we can improve the rate performance of LiCoO2, if we are able to coat specific facets of LiCoO2 powders except for the charge-transfer planes.
In this presentation, we introduce, for the first time, a new plane-selective coating of LiCoO2. For example, we demonstrate that metal oxides coating layers are grown plane-selectively on the LiCoO2(001) surface. We show synthesis details for the plane-selective coating of LiCoO2. Scanning transmission electron microscopy (STEM) analysis was carried out with a high-angle annual dark field (HAADF) mode to observe the plane-selective coatings. The electrochemical performance of the plane-selectively coated LiCoO2 was better than that of the conventionally coated LiCoO2. Moreover, we discuss the origin of the plane-selective coating of LiCoO2.
References
[1] B. Xu, D. Qian, Z. Wang, Y. S. Meng, Materials Science and Engineering: R: Reports 2012, 73, 51
[2] W. Li, A. Dolocan, P. Oh, H. Celio, S. Park, J. Cho, A. Manthiram, Nat Commun 2017, 8, 14589
[3] Y.-K. Sun, C. S. Yoon, S.-T. Myung, I. Belharouak, K. Amine, Journal of The Electrochemical Society 2009, 156, A1005
Towards High-Voltage Sodium-Ion Batteries Based on Aqueous Electrolytes
Authors: Kühnel Ruben-Simon , Reber David , Battaglia Corsin 
Published: February 2020

Water-in-salt electrolytes enable the operation of batteries at higher voltage than previously possible with conventional aqueous electrolytes.[1,2] High-voltage aqueous batteries are potential candidates for stationary electricity storage where low total cost of ownership is more important than high energy density.
To date, most water-in-salt studies have focused on enabling aqueous lithium-ion batteries. However, considering the high salt content of water-in-salt electrolytes, sodium-ion batteries appear particularly interesting for this approach as sodium salts are typically significantly less expensive than their lithium analogues, but typically exhibit insufficient solubility due to the lower charge density of Na+ compared to Li+.[3]
Recently, we discovered that NaFSI displays very high solubility in water, enabling a wide electrochemical stability window.[4] Although S-F bonds present in the FSI anion are known to be relatively weak and hence make FSI prone to hydrolysis, we demonstrate a 2 V class NaTi2(PO4)3/Na3(VOPO4)2F cell with an excellent capacity retention of 85% after 500 cycles at 1C. To the best of our knowledge, the specific energy of our cell of 65 Wh/kg (based on the active masses of both electrodes) is the highest reported to date for an aqueous sodium-ion battery. Using strategies to prevent electrolyte crystallization, we also demonstrate stable cycling at temperatures as low as -10 °C.
[1] L. Suo, O. Borodin, T. Gao, M. Olguin, J. Ho, X. Fan, C. Luo, C. Wang, K. Xu, Science 350 (2015) 938.
[2] Y. Yamada, K. Usui, K. Sodeyama, S. Ko, Y. Tateyama, A. Yamada, Nat. Energy 1 (2016) 16129.
[3] D. Reber, R.-S. Kühnel, C. Battaglia, Sustainable Energy Fuels 1 (2017) 2155.
[4] R.-S. Kühnel, D. Reber, C. Battaglia, ACS Energy Lett. 2 (2017) 2005.
Casein As a Novel Binder for Silicon-Based Electrodes for Li-Ion Batteries
Authors: Chandrasiri Dilni Kaveendi , Lucht Brett L. 
Published: February 2020

High capacity electrode material has been studied over the years due to the constant demand for high energy density applications in li ion batteries. Among others, silicon has been considered a more promising candidate for its high theoretical capacity of ~ 3600 mAh/g, abundant resources, low cost and low toxicity. However, silicon-based electrodes face rapid degradation due to the extensive volume variation (~300%) in the charge discharge process. Binders used in the electrode fabrication plays a crucial role in these high-performance electrodes since it can reduce the mechanical fracture in the cycling process.
Utilization of polymeric material as binders to hold the active material has been the most common approach used in the li ion battery electrode preparation. Recent studies carried out by Nguyen et. al have shown the use of small molecular carboxylic acids as binders which showed an improvement in the cell performance for silicon electrodes. In this study we introduce a cheap and environmentally friendly alternative that could be used as a non-polymeric binder for silicon electrodes. Further, the electrode preparation can be done in water medium which reduces the introduction of toxic organic solvents such as NMP to the environment. Casein is a milk protein found in bovine milk rich in amine groups and carboxylic acid groups which can form bonds with the silanol groups in silicon. A comparative study conducted between PVDF and Casein as binders have shown that when casein was used as binder, it shows better performance compared to PVDF. It has 12% higher capacity retention compared to PVDF with a 2200 mAh/g capacity after 50 cycles. Surface morphology and Solid electrolyte interface was analyzed using electron microscopy techniques and spectroscopic methods and the results will be discussed.
Mg-Doped Na3V2(PO4)2F3/C Cathodes for Sodium Ion Batteries
Authors: Puspitasari Diah Agustina , Lee Tai-Chou , Chang Jeng-Kuei 
Published: February 2020

Lithium-ion batteries (LIBs) are competent energy storage devices that have been used for electronic devices. However, for large-scale applications, there are concerns about the cost and lithium reserves. The market requires batteries which have high energy density, high safety, low cost, and environmental benignity [1-2]. Recently, the sodium-ion batteries (SIBs) have received much attention because of their similar electrochemical properties with LIBs. Na3V2(PO4)2F3 has been developed as a cathode material for SIBs due to high voltage, high thermo-stability, and high capacity [3].
Na3V2(PO4)2F3/C (NVPF/C) with a NASICON structure has a Na+ intercalation potential of 3.76 V. However, the NVPF/C has a low electronic conductivity which hinders the capacities and rate capability. Carbon coating and particle size reduction can improve the electrochemical performance. In addition, this work use Mg2+ doping attempting to increase the bulk conductivity of NVPF. Na3V2-xMgx(PO4)2F3/C cathodes are successfully synthesized using a sol-gel method with citric acid as the reducing agent and carbon source. X-ray diffraction (XRD) analysis confirms that Mg has been doped into NVPF/C. The XRD peak shifts indicate a lattice contraction due to the smaller atomic size of Mg as compared to V. The Mg-doped NVPF/C cathodes show promising properties for SIB applications.

Reference:

[1] M. Arumugam and Y. Ya. Advance Energy Mater., 2018, (8), 1-11
[2] W. Feixiang, Z. Chenglong, C. Shuangqiang, L.Yaxiang, H. Yanglong, H. Yong-sheng, M. Joachim and Y. Yan, Material Today. doi.org/10.1016/j.mattod.2018.03.004, 2017
[3] Z. Liu, Y.-Y. Hu, M. T. Dunstan, H. Huo, X. Hao, H. Zou, G. Zhong, Y. Yang and C. P. Grey. Chem. Mater., 2014, (26), 2513–2521.
Lithiation/Delithiation Behaviors of Electrode/Electrolyte Materials for Li Ion Batteries Viewing from Defect Reactions
Authors: Fung Kuan-Zong , Tsai Shu-Yi , Liu Chi-Yang , Chang Li-Fu , Huang Bo-Yuan 
Published: February 2020

For functional materials used for lithium ion batteries, their electrochemical properties are highly dependent on their defect structures. For examples, the reversible capacity of layered cathode such as LiCoO2 is limited by its highly defective layered structure when state of charge greater than 50%. On the other hand, capacity of spinel or olivine cathodes show higher delithiation rate without noticeable phase change. Furthermore, with oxygen defects formed in Li2MnO3, the capacity of Li-rich layer-structured cathode formulated as xLi2MnO3-(1-x)LiMO2(M = Mn, Ni, Co, etc.) was able to provide high reversible capacity (>250 mAh/g) for Li-ion battery applications. Similarly, the zero-strain anode materials Li4Ti5O12 shows high interface polarization and low rate capability due to low electronic defects. Hopefully, the rate capability may be improved by introduction of more electronic defects on Ti cation sublattice.
In additions, the properties of solid state Li ion conductors for all-solid-state lithium batteries is strongly affected by their defect structures as well. Due to its better safety characteristics, solid-state lithium battery may use more reactive anode, such as Li. Thus, it is extremely crucial to find a stable solid electrolyte when the high-capacity Li anode is used. In our study, the stability of perovskite-based La0.50Li0.50TiO3, NASICON-based Al-doped LiTi2(PO4)3, and garnet-based Li7La3Zr2O12 against metallic Li were investigated. After La0.50Li0.50TiO3 reacted with Li, the electron injection accompanied by the incorporation (insertion) of Li ion into vacant cation sites was likely to take place. The apparent reduction of tetravalent Ti into trivalent Ti was observed in La0.50Li0.50TiO3. On the other hand, Al-doped LiTi2(PO4)3, and garnet-based Li7La3Zr2O12 are much more stable when Li anode is used. For these solid electrolytes, the difference in stability against metallic Li may be rationalized based on their defect structures and corresponding atomic arrangements.
Diffraction Signal from Sodium Cluster in Hard Carbon: A Combined Experimental and Computational Study
Authors: Morikawa Yusuke , Nishimura Shinichi , Watanabe Eriko , Yamada Atsuo 
Published: February 2020

Na-ion batteries have attracted increasing attention as large-scale energy storage devices. Hard carbon is a standard anode material owing to its large capacity and good cycling stability1, 2. However, sodium storage mechanism of hard carbon has not been fully understood due to its low crystallinity and diversity of microstructure. This study aimed to systematic understanding of the relationship between microstructure and sodium storage behavior with special attention to the diffraction signal from sodium cluster confined in nanopores.
Hard carbons were synthesized by hydrothermal treatment of sucrose and subsequent high-temperature carbonizations at T = 1000-1900 °C (denoted as HC-T). The charge-discharge tests were carried out using half-cells. As the heat-treatment temperature increased, the capacity of the high potential region (> 0.2 V) decreased while the plateau region (< 0.2 V) become dominant. HC-1400 showed the highest overall capacity (347 mAh g-1) and initial coulombic efficiency (95.2%). Reaction mechanism analyses were performed on three representative samples, HC-1000, HC-1400, and HC-1900.

Ex-situ small angle X-ray scattering (SAXS) measurements revealed (i) the nanopores become larger with decreasing their number for higher annealing temperatures, (ii) insertion of sodium into the nanopores proceeded under ca. 0.07 V. When electrodes were overcharged exceeding the sodium deposition voltage (ca. –0.01 V), the sodium density in the nanopores became comparable to that of bulk bcc sodium. Besides, apparent smaller capacity of HC-1900 was analyzed to be a kinetic observation with larger cathodic polarization.
Careful ex-situ X-ray diffraction measurements have detected smaller mean interlayer distances in order of HC-1900 < HC-1400 < HC-1000. Expansion of interlayer distance upon sodium insertion was observed for HC-1000 and HC-1400, but not at all for HC-1900, suggesting the existence of a threshold interlayer distance to allow sodium insertion. Importantly, for the first time, we have succeeded to detect a broad peak appeared around 29° as a signature of sodium insertion into the nanopores, and its origin was analyzed to be diffraction from sodium clusters in the nanopores using DFT-MD simulations.
Based on these analyses, criteria for better hard carbon will be discussed in the poster.

Figure 1
Failure Analysis of the Rechargeable Porous Zinc Electrode in Alkaline Electrolyte
Authors: D'Ambrose Michael Joseph , Yadav Gautam Ganapati , Turney Damon , Gallaway Joshua W. , Nyce Michael , Messinger Robert J. , Banerjee Sanjoy 
Published: February 2020

Metallic zinc (Zn) is an attractive negative electrode material for rechargeable batteries because it is a non-toxic, earth abundant metal. It has a low equilibrium potential of -1.35 V vs. mercury-mercuric oxide (Hg/HgO) in concentrated alkaline electrolyte and a high gravimetric discharge capacity of 820 mAh/g. During discharge, Zn oxidizes and forms a dissolved complex known as the zincate ion, Zn(OH)4
2-, from which zinc oxide (ZnO) precipitates as a solid. On charge, Zn(OH)4
2- is reduced to metallic Zn. Motivation to study the Zn electrode in rechargeable batteries is driven by a target overall battery energy density of 200 Wh/L that is sustainable for 500 or more charge-discharge cycles. This corresponds to a Zn electrode discharge density in the range of 650 mAh/mL.
The cycle life of the porous Zn electrode in concentrated alkaline electrolyte is observed to decrease with increasing percentage of discharge capacity of Zn accessed. The percentage of discharge capacity of Zn accessed is known as the depth of discharge (DOD). Zn electrodes were cycled in the range of 1% to 15% Zn DOD in zinc-manganese dioxide (Zn-MnO2) batteries and in the range of 15% to 30% Zn DOD for zinc-nickel (Zn-Ni) batteries. Additives were incorporated into the zinc electrodes for the tests done on Zn-Ni batteries. Additives used were surfactant cetyltrimethylammonium bromide (CTAB), bismuth oxide (Bi2O3), synthetic layered silicate Laponite, and calcium hydroxide (Ca(OH)2). The potential values of the Zn electrodes vs. Hg/HgO reference electrodes were recorded.
During healthy galvanostatic discharge, Zn electrodes displayed a nearly constant potential vs. Hg/HgO at approximately -1.35 V. Tests that failed due to Zn exhibited a shift from this equilibrium potential that corresponded to a loss of cell voltage. This shift may be attributed to concentration overpotential as ZnO is precipitated, thereby inhibiting the hydroxide ions from reaching the reacting metal interface. The shift may also be due to formation of a passivated layer on the electrode which effectively blocks the remaining active material. There are generally two regimes observed in the potential curves of the Zn electrode vs. Hg/HgO prior to cell failure. Beyond the healthy plateau at -1.35 V, the first regime consists of a sloping potential while the second regime is an additional plateau. The second plateau shifts with increasing cycle number and corresponds to cell death. See the attached figure for discharge curves of a Zn electrode cycled at 5% Zn DOD. The second plateau is believed to be due to passivation of the Zn electrode. The additives were observed to modify the discharge potential curve of the Zn electrode vs. Hg/HgO.

Figure 1
The Influence of Inactive Mn4+ Cation on the Redox Behavior of Active Co3+ Cation and O2- anion in Cathode Material.
Authors: Wang Xue-Long , Xiao Ruijuan , Fan Xiulin , Yu Xiqian , Hu Enyuan , Yang Xiao-Qing 
Published: February 2020

Co3+/Co4+ redox has been widely utilized in layer structured cathode material for Lithium ion batteries due to its relatively high potential (vs Li+/Li) and good stability during cycling. In comparison, Mn4+ cation is proven to stay inactive for a wide potential range while it activates anionic oxygen redox in Li2MnO3. With introduction of Mn into LiCoO2 system, our experimental results showed that crystal structure had changed into spinel structure with Fd-3m symmetry and the redox behavior of Co3+ and O2- changed dramatically. The redox potential of Co3+/Co4+ increased much from c.a. 3.8V vs Li+/Li in layer structured LiCoO2 to over 5V vs Li+/Li in spinel LiCoMnO4. Meanwhile, the hard X-ray absorption spectroscopy results implied that less oxygen contribution to charge compensation during delithiaion process with Mn substituion. Through careful DFT calculations we revealed that the differences are mainly caused by the inactive dopant Mn elements rather than the transformation of crystal structure. More ionic-like Mn-O bonds induces stronger electron localization in Li-Mn-Co-O system compared with Li-Co-O system and, therefore, changes redox behaviors of Co3+/Co4+ and oxygen participation in charge compensation. Combined with soft X-ray absorption spectroscopy technique, the effects of Mn substitution on electronic hybridization status in Li-Co-O system was verified.
Acknowledgement
This project was supported by the U.S. Department of Energy, the Assistant Secretary for Energy Efficiency and Renewable Energy, Office of Vehicle Technologies through Advanced Battery Material Research (BMR) program (Battery 500 consortium) under Contract No. DESC0012704
Three-Dimensional Structural Analysis of All-Solid-State Electrode with Oxide-Based Solid Electrolyte
Authors: Park Joonam , Kim Dohwan , Appiah Williams Agyei , Song Jihun , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

All-solid-state batteries (ASSBs) are promising secondary batteries which have been studied for high energy density and safety. However, ASSBs have not had excellent electrochemical performance owing to using solid electrolyte instead of liquid electrolyte. Two main reasons are very low ion conduction property due to complex pathway made with the solid electrolytes and the large decline of the contact area between active materials and the solid electrolytes. In spite of distinct faults were already recognized, there have hardly been the studies because of the difficulty of obtaining the value by using the experiment.
In this study, we tried to gain the values from the simulation technics, which helped us draw the three-dimension electrode structure and check essential properties such as the contact area, tortuosity, and conductivity etc. with the variable electrochemical performance. In order to verify the appropriacy of our computational approach, the component ratio experiment that had been rudimentary for the electrode design was simulated under condition changing the ratio of natural graphite as the active material and LSTP (Li2O-SiO2-TiO2-P2O5) as the oxide-based solid electrolyte and then were compared and discussed with the data that anyone could confirm as the experiment.