bluuebunny/crossref_metadata_2025_split huggingface dataset:
Fast and Controllable Prelithiation of Hard Carbon Anodes for Lithium-Ion Batteries
Authors: Zhang Xiaoxiao , Qu Huainan , Ji Weixiao , Zheng Dong , Ding Tianyao , Abegglen Caleb , Qiu Dantong , Qu Deyang 
Published: December 2020

As one of the potential alternatives to graphite, non-graphitizable hard carbon (HC) is of great interest for its high capacity and better rate performance. It is generally accepted that the higher capacity of HC comes from the random arrangement of single graphene layers, which provides extra voids to accommodate lithium.1 However, its practical application is hindered by a large irreversible capacity and thus low initial Coulombic efficiency (ICE) (<80%), which originates from the relatively large surface area, causing solid electrolyte interface (SEI) formation and side reaction between Li ions and surface functional groups. 2

Chemical prelithiation is one of the most effective method to compensate the Li loss and thus improve the ICE. It refers to the application of Li-containing reagents with strong reducing capabilities, which transfer the Li ions to the anode materials along with the redox reaction.3-4 The operation is rather simple and shows great potential for industrial application with a suitable roll-to-roll design. In this study, the chemical prelithiation reagent, Li-biphenyl-tetrahydrofuran, was evaluated for its prelithiation capability in hard carbon electrodes through the immersion method. The prelithiation extent can be easily controlled by tuning the reaction time. A short time of 30 s results in a high ICE of ~106% in half cell. The improvement of ICE was evaluated in full cells as well. When matched with a LiNi1/3Co1/3Mn1/3O2 cathode, the full cell with the prelithiated hard carbon anode exhibits a much improved ICE and cycling performance than those of the pristine full cell. SEM, XPS, and EIS analysis were conducted to investigate the SEI difference between pristine and prelithiated samples, and the prelithiation mechanism was proposed.

References

(1) Nagao, M.; Pitteloud, C.; Kamiyama, T.; Otomo, T.; Itoh, K.; Fukunaga, T.; Tatsumi, K.; Kanno, R. Structure Characterization and Lithiation Mechanism of Nongraphitized Carbon for Lithium Secondary Batteries. J. Electrochem. Soc.
2006,
153, A914-A919.
(2) Xing, W.; Dahn, J. R. Study of Irreversible Capacities for Li Insertion in Hard and Graphitic Carbons. Journal of The Electrochemical Society
1997,
144, 1195-1201.
(3) Scott, M. G.; Whitehead, A. H.; Owen, J. R. Chemical Formation of a Solid Electrolyte Interface on the Carbon Electrode of a Li‐Ion Cell. J. Electrochem. Soc.
1998,
145, 1506-1510.
(4) Tabuchi, T.; Yasuda, H.; Yamachi, M. Li-doping process for LixSiO-negative active material synthesized by chemical method for lithium-ion cells. J. Power Sources
2005,
146, 507-509.
(Invited) The Role of Electrolyte Solution in Next-Generation Batteries
Authors: Johnson Lee R 
Published: December 2020

Lithium-ion electrolytes are predominantly base on carbonate solvents and have been instrumental in the success of the lithium-ion battery.1 Uniquely, their ability to form a stable solid-electrolyte interphase (SEI) at lithiated carbon electrodes underpins the battery.2 Unfortunately, the lithium-ion battery is approaching maturity and attention is turning to alterative next-generation batteries that are able to deliver enhancements in energy, power, sustainability and cost. Often, the challenges in next-generation batteries are very different from those found in the lithium-ion battery.3 New understanding and advancements in electrolyte chemistry will be needed to realize these technologies.
Here, we look at how electrolyte chemistry and impurities can control charge/discharge reactions in next-generation batteries. For example, the lithium-air battery has one of the highest specific energies of any known secondary battery chemistry, but faces significant challenges.4 The battery operates via oxidation of lithium metal at the anode, coupled to reduction of oxygen and formation of lithium peroxide at the cathode and these reactions are heavily influenced by the electrolyte chemistry.5 Moreover, to operate in air they must tolerate H2O, and here we describe how solvent chemistry is able to control the discharge route from a 2-electron reaction to an irreversible 4-electron reaction. This theory explains why cells are able to tolerate 1 M H2O,6,
7 and we show that with judicious selection of the electrolyte, up to 4 M H2O can be tolerated at the positive electrode of the battery. The impact of electrolyte chemistry on anode reactions will also be discussed. Recently, there has been significant research into magnesium anodes due to their high volumetric capacity (twice that of metallic lithium) and limited dendrite formation.8 Here we consider the nature of SEI films at magnesium in simple salt glyme ether electrolytes and how this impacts the cyclability of magnesium metal. Our results demonstrate the formation of a dynamic SEI at magnesium.

Reference
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K. U. Schwenke, M. Metzger, T. Restle, M. Piana, and H. A. Gasteiger, J. Electrochem. Soc., 162, A573–A584 (2015).

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R. Attias, M. Salama, B. Hirsch, Y. Goffer, and D. Aurbach, Joule, 3, 27–52 (2019)
Integration of Low Melting Temperature Electrolyte in Thermal Batteries
Authors: Yazdani Aliakbar , Sanghadasa Mohan , Botte Gerardine G. 
Published: December 2020

Thermal batteries usually operate at temperatures higher than 400 °C. This high operating temperature requires a complex thermal and mechanical design of the battery components and hermetically sealed casing. Reduced operating temperature thermal cells can benefit from the majority of intrinsic characterizations of thermal batteries such as safety, robustness, and infinite shelf life while mitigating the challenges related to the high operating temperature batteries such as exotic thermal insulation materials, complicated internal pyrotechnic heat source, and heavy packaging. To integrate the thermal batteries into a wider range of applications such as bore-hole probes, smart grid energy storage, and geothermal energy applications, operating temperatures of these batteries should be reduced.
The most common design for thermal batteries is pellet stacks. The pellet pressing fabrication method inherently causes issues due to the fragility of the pellets, making handling and assembly of the cells arduous. Additionally, due to the liquid nature of molten salt electrolyte used in these batteries, a structure to immobilize the electrolyte layer during the operation of the battery is required. The role of the immobilizing component is also to prevent short circuiting while the battery is affected by severe physical shock or vibration. The most commonly used binder material in today’s thermal batteries is magnesium oxide (MgO). Extensive investigations were conducted on the properties and the electrochemical effect of using MgO as the binding material, besides, its fabrication process is well optimized. However, using MgO is not without its drawbacks. To prevent short-circuiting during the cell operation especially in the presence of an external shock to the system, approximately 30 vol.% of the separator layer should be dedicated to MgO, resulting in lower than desired energy density. Ceramic felts showed promising results in recent studies. High level of porosity (e.g. 96% bulk porosity), outstanding stability at elevated temperatures, and mechanical stiffness could be the key to make batteries that can operate for a longer time.
Our research group has previously developed a novel eutectic electrolyte mixture using potassium bifluoride and different lithium salts such as lithium fluoride as the low melting point electrolytes. In this research, initially, the integration of this electrolyte mixture in a thermal cell was tested. Consequently, aluminum oxide (Al2O3) and yttria-stabilized zirconia (YSZ) ceramic felts were loaded with the low melting electrolyte as an alternative to the current pellet-based separator layer. Finally, (i) the assembly of the cell, (ii) the thermal analysis of the components by differential scan calorimetry (DSC) method, (iii) the new electrolyte/ceramic-felt combination’s loading level, wetting properties, infiltration, and leakage, and (iv) electrochemical behavior of the new thermal battery such as discharge capability and energy density were investigated.
(Battery Division Student Research Award Address Sponsored by Mercedes-Benz Research & Development) Investigating Anomalous Conductivity in Low Permittivity Electrolytes for Multivalent Battery Applications
Authors: Self Julian , Hahn Nathan T , Fong Kara D. , McClary Scott A , Zavadil Kevin R , Persson Kristin A. 
Published: December 2020

Many of the liquid electrolyte candidates for multivalent batteries exhibit increasing molar conductivity with concentration. In other words, the concentration-normalized conductivity increases as a function of salt concentration. This is in contrast to conventional electrolytes, e.g. aqueous or cyclic carbonate-based electrolyte solutions, where the molar conductivity decreases with concentration due to increased viscosity and ion aggregation. Low permittivity electrolytes with increasing molar conductivity include Ca(BH4)2 in tetrahydrofuran, Mg(TFSI)2 in monoglyme and Mg(TFSI)2 in diglyme.
In order to investigate the origin of this anomalous molar conductivity trend, we study the physicochemical properties of the electrolytes using a combined computational/experimental approach. Ab initio calculations and classical molecular dynamics simulations are undertaken to study ion speciation, ion activity and changes to solution permittivity. Furthermore, we undertake conductivity, microwave and Raman spectroscopy measurements.
Solution NMR Studies of Electrolyte Decomposition Pathways
Authors: Rinkel Bernardine L. D. , Hall David S. , Temprano Israel , Grey Clare P. 
Published: December 2020

One approach to increasing the energy density of lithium-ion batteries is to increase the operational upper voltage limit. However, higher cell voltages tend to lead to rapid capacity fade and shorter cycle life. This is typically ascribed to the loss of oxygen due to surface reconstructions of the cathode material, increased electrolyte oxidation rates, and transition metal dissolution.
It is well-known that electrolyte decomposition can negatively impact cell behaviour and lifetime by causing gassing, electrochemical impedance growth, or slippage, and that extensive electrolyte oxidation at high cell voltages can induce eventual rapid capacity loss or ‘rollover’ failure.1,2 Whereas the reduction processes at the anode have been well-studied and are generally understood,3 the chemical pathways and mechanisms for oxidation at the cathode remain relatively unknown. It is desirable to develop a more detailed chemical understanding of electrolyte degradation in support of longer-lasting high voltage materials and cell designs.
Herein, operando pressure measurements, liquid-state NMR, and electrochemical methods are combined to study electrolyte oxidation at multiple cell voltages. LiCoO2 (LCO)/Li cells were cycled with a lithium-ion conducting ceramic separator to identify the degradation products formed at the anode and cathode separately and to prevent further reactions of these species on the opposite electrode. The results are compared with the species generated by electrochemical oxidation of the electrolyte in a simple H-cell and with cells cycled without a separator. A major finding of the present work is that all degradation products from the cathode side of the LCO/Li cells can be explained by chemical oxidation of the electrolyte, involving oxygen evolved from the cathode surface, at least up to 4.9 V vs. Li/Li+. This result is consistent with and complementary to previously reported online electrochemical mass spectrometry results4 and has significance for nickel-containing cathode materials (e.g., NMC). Finally, a comprehensive summary of electrolyte degradation pathways was constructed by analysing a series of multinuclear and one- and two-dimensional NMR spectra.

Reference
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:

[1] L.M Thompson, W. Stone, A. Eldesoky, N.K. Smith, C.R. M. Mcfarlane, J. S. Kim, M. B. Johnson, R. Petibon and J. R Dahn, J. Electrochem. Soc., 165 (2018), 2732-2740.
[2] X. Ma, J. E. Harlow, J. Li, L. Ma, D. S. Hall, M. Genovese, M. Cormier, J. R. Dahn, S. Buteau, J. Electrochem. Soc., 166 (2019), A711-A724.
[3] S. K. Heiskanen, J. Kim, B. L. Lucht, Joule, 3 (2019), 2322-2333.
[4] R. Jung, M. Metzger, F. Maglia, C. Stinner, H. A. Gasteiger, J. Phys. Chem. Lett., 8 (2017), 4820-4825.
Electrolyte-Dependent SEI Formation and Its Consequences on Mg Electrode Cycling
Authors: Holc Conrad , Hopkinson Emily , Dimogiannis Konstantinos , Johnson Lee R 
Published: December 2020

Recently, there has been significant research into magnesium batteries due to their potential as a beyond Li-ion technology. This is due to a number of beneficial properties of the Mg negative electrode, including high volumetric capacity, twice that of metallic Li (Figure 1) and lack of dendritic growth on cycling.1,2 However, current electrolytes are insufficiently stable to the Mg electrode, leading to reduction of the electrolyte and formation of a solid electrolyte interphase (SEI), which is believed to be detrimental to performance.3-7 Furthermore, a majority of reports have used noble metal electrodes to assess the suitability of electrolytes with Mg, which is not representative of the conditions in a practical Mg battery.8,9

Here, we probe the cycling behavior of bulk Mg electrodes in two electrolytes, one Grignard-based (BuMgCl in THF) and the other glyme ether-based (Mg(TFSI)2 in TEGDME). Cyclic voltammetry identified different plating and stripping behaviour in each electrolyte, with the Grignard demonstrating plating/stripping typical for a bulk electrode, while Mg stripping in the glyme ether resulted in a finite peak in the cyclic voltammetry. This unexpected result suggests a protective SEI forms on the Mg surface in the glyme ether, which critically still allows Mg-ion diffusion. The nature of the SEI in both electrodes was characterised using FTIR spectroscopy and SEM imaging, confirming that the nature of the SEI is dependent on the electrolyte and that it affects the way in which Mg electrodes cycle. Our results suggest that it is possible to protect Mg electrodes with a stable SEI and allow the use of electrolytes with increased oxidative stability.

Reference
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:

[1] M. Matsui, J. Power Sources 196 (2011) 7048–7055.
[2] J. Song, E. Sahadeo, M. Noked, S. B. Lee, J. Phys. Chem. Lett. 7 (2016) 1736–1749.
[3] M.-S. Park, J.-G. Kim, Y.-J. Kim, N.-S. Choi, J.-S. Kim, Isr. J. Chem. 55 (2015) 570–585.
[4] S. Y. Ha, Y. W. Lee, S. W .Woo, B. Koo, J. S. Kim, J. Cho, K. T. Lee, N. S. Choi, ACS Appl Mater Interfaces 6 (2014) 4063–4073.
[5] I. Shterenberg, M. Salama, H. D. Yoo, Y. Gofer, J.-B. Park, Y.-K. Sun, D. Aurbach, J. Electrochem. Soc. 162 (2015) A7118-A7128.
[6] O. Tutusaus, R. Mohtadi, N. Singh, T. S. Arthur, F. Mizuno, ACS Energy Lett. 2 (2017) 224-229.
[7] M, S. Ding, T. Diemant, R. J. Behm, S. Passerini, G. A. Giffin, J. Electrochem. Soc. 165, (2018) A1983-A1990
[8] K. Ta, K. A. See, A. A. Gewirth, J. Phys. Chem. C 122 (2018) 13790–13796.
[9] J. G. Connell, B. Genorio, P. Papa, D. Strmcnik, V. R. Stamenkovic, N. M. Markovic, Chem. Mater. 28 (2016) 8268–8277.

Figure 1
A Multi-Analytical Approach for the Surface Reactivity Characterisation of Pristine NMC811: Towards Gassing Comprehension
Authors: Laurita Angelica , Cabelguen Pierre Etienne , Zhu Liang , Hamon Jonathan , Fernandez Vincent , Guyomard Dominique , Dupré Nicolas , Moreau Philippe 
Published: December 2020

The urgent demand of the EV industry for high energy density cathode materials is currently leading the battery market towards Ni-rich NMCs. Despite that, the gassing phenomenon that affects these materials has huge impacts on their electrochemical properties and causes security issues that prevent the commercialization of 80% Ni-rich NMC.
In order to obtain a fundamental understanding of this gassing generation, we decided to focus on the surface reactivity of the pristine NMC811 provided by Umicore, with emphasis on the material surface’s and bulk’s changes during the native contamination layer formation. A multi-analytical approach is thus required to analyse all the aspects of such a complex system.
The sapient use of high field 7Li MAS-NMR allowed us to successfully filter the signal of the diamagnetic compounds at the surface of the material and to quantify the corresponding environments. The speciation of these compounds, not being possible by MAS-NMR, was defined by low temperature XPS experiments.
It was thence possible to characterise the reactive surface of the primary particles in contact with this contamination layer at the nanometric scale by STEM-EELS with both high energy and high spatial resolutions. The oxidation state and the crystalline phase were successfully determined crossing the high quality experimental spectra recorder with the K2 counting direct detector (Gatan) installed on our new Themis Z G3 (Thermo Fisher Scientific) and EELS edges simulations.
On the other hand, low field 1H MAS-NMR gave us a new insight on the proton environments enabling us to clearly see the presence of a proton chemically bonded inside the material for the first time and to correlate it with the surface reactivity investigated with the other techniques.
The combined use of these advanced characterisation techniques, all available in the IMN, allowed us to shed a new light on the understanding of the pristine industrial NMC811 with always the same material history.
Hard Carbon Ethylene Carbonate Interfaces – Atomic Scale Insight into Surface Termination, Defects, Functional Groups, and Roughness on Electrolyte Breakdown, Metal Adsorption, Intercalation and Nucleation
Authors: Olsson Emilia , Cai Qiong 
Published: December 2020

In the search for post lithium ion batteries (LIBs), sodium ion batteries (NIBs) are gaining traction, but fundamental understanding of the atomic scale interactions at the anode electrolyte interfaces in NIBs remains poorly understood. In moving from LIBs, the LIB anode material graphite was found to be unsuitable for NIBs. Instead, hard carbon anode materials have arisen as one of the most promising electrode materials for sodium ion batteries (NIBs), which are also suitable for use with carbonate based electrolyte solvents. Hard carbons are complex amorphous carbon structures with randomly orientated, defective, and curved graphene nanosheets, and turbostratically stacked graphitic layers. This complex structure leads to a plethora of carbon structural motifs being present in the anode, leading to a large number of potential morphologies having to be taken into account when investigating the anode electrolyte interface.
In this study, we use ab initio molecular dynamics to investigate the effect of surface roughness, disorder, defects, and termination on the electrolyte anode interactions in the EC (electrolyte solvent) | hard carbon (anode) system. These simulations show that EC intercalation and breakdown is directly influenced by the carbon surface termination and surface roughness. Furthermore, defects were found to be more probable to form in terms of defect formation energies at strained and curved carbon morphologies. These defects were also found to have a direct impact on the sodium binding to the anode. The effect of all these different structural motifs on sodium adsorption, intercalation, and diffusion were simulated to form an understanding of the anode electrolyte interfacial reactions. One consequence of electrolyte molecule breakdown, but could also be an effect of anode synthesis method, is the presence of functional groups at the carbon surface. From density functional theory simulations of functional groups O, OH, NH2, and COOH at different carbon motifs (planar basal plane, H-terminated edges, and curved morphologies) we could show that O-functional groups from an energetical perspective are highly probable to form on these surfaces, and can act as favourable sodium storage sites. The hydroxyl group on the other hand were found to form inorganic NaOH compounds, which could contribute to irreversible capacity.
Acknowledgment
The financial support from EPSRC (Engineering and Physical Sciences Council) under the grant number EP/M027066/1, and EP/R021554/2, is acknowledged.
Molten Salt Electrolytes: Computational Analysis of Transport, Electrochemical Properties and Designing New Mixtures
Authors: Radhakrishnan Balachandran , Ravichandran Ashwin , Lawson John W 
Published: December 2020

Electric aircraft propulsion has gained traction over the last decade due to possible high-energy density electrochemistries with reasonable cycle life and identification of non-flammable chemistries that can guarantee much better safety. Commercial Li-ion batteries cannot reach such high capacities because of weight limitations that arise from the widely used intercalation electrodes. Also, use of organic electrolytes make them highly susceptible to fire on exposure to air and humidity. Currently, use of Lithium metal anode along with conversion electrochemistries such as Li-O2 and Li-S are being pursued to achieve such high energy densities. Safer inorganic solid-state electrolytes, recently discovered Water-in-Salt electrolytes, molten salt electrolytes are some of the alternatives being pursued for a safer/non-flammable battery.
Of these safer alternatives, molten-salt electrolytes offer some attractive properties: liquid at operating temperatures resulting in better electrode-wetting, stable interface with Li-metal anodes and good ionic conductivity; their only drawback being high operating temperatures. In this talk, we will discuss some of the computational studies, driven via atomistic simulations, of the properties of molten-salt electrolytes including transport mechanism and interface stability. We will also discuss predicting electrochemical properties of these high-temperature electrolytes. Further, we will discuss a thermodynamic approach to predicting new molten-salt eutectics with lower melting points.
The Importance of Competitive Solvent and Anion Coordination for Multivalent Battery Electrolytes
Authors: Hahn Nathan T , McClary Scott A , Zavadil Kevin R 
Published: December 2020

Multivalent battery concepts based on magnesium or calcium metal anodes have the potential to provide higher energy density than traditional lithium ion batteries. However, current multivalent electrolytes possess less than optimal compatibility with these reactive metals and with desirable high voltage cathode materials. Understanding the origin of these issues requires an understanding of multivalent cation coordination environments in both the bulk and at the relevant interfaces. In this presentation, elucidation of the relative coordination strengths of “state-of-the-art” multivalent battery salts and solvents will be described. Moreover, the impact of these competitive coordination tendencies on metal deposition efficiency will be discussed along with the efficacy of tuning such interactions to improve magnesium and calcium electrolyte performance.
This work was supported by the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.