bluuebunny/crossref_metadata_2025_split huggingface dataset:
Triggering the in Situ Electrochemical Formation of High Energy Density Cathode Material from MnO
Authors: Zhang Leiting , Chen Guohua , Tarascon Jean-Marie 
Published: February 2020

High energy density electrode materials are in pressing needs for next generation Li-ion batteries. While the stellar, laboratory-wise, is intercalation-type layered oxides involving both cationic and anionic redox processes,1 conversion-type fluorine-based materials are also demonstrating attractive performances owning to the multi-electron transfer and high electronegativity of fluorine. Compared to pure fluorides, metal oxyfluorides possess higher conductivity and better electrochemical activity.2 However, their performances are overwhelmingly dependent on several parameters, such as nominal composition, synthesis conditions, particle size and morphology. Recently, Kang and co-workers proposed a “redox composite” model, where a redox center (transition metal oxide/fluoride, MO/MF) and a Li+ reservoir (LiF) were blended by ball milling and directly used as the cathode.3This allows in principle countless pairs of composite electrodes to be explored as high energy density positive electrodes.
Herein, we report that manganese monoxide (MnO), who has long been believed as a promising conversion anode material based on the Mn2+/Mn0 redox couple, can indeed turn into a high energy density cathode material delivering over 200 mAh g-1 capacity with an average potential around 3 V (Fig. 1). A one-step high energy ball milling method is adopted to trigger the reactivity of nanosized MnO particles. This process does not require any sophisticated synthesis routes, and can be easily scaled up for volume production.
Interestingly, this encouraging result is achieved without any LiF addition, thus calling for further exploration and understanding of the reaction paths. Based on various characterization techniques, it is found that the electrochemical activity is deeply rooted in the electrode-electrolyte interfacial reactions, and is strongly correlated with the stability of LiPF6-based organic electrolyte. This finding raises the practical utility of such electrochemically made high capacity electrodes.
Reference:
1 M. Sathiya, G. Rousse, K. Ramesha, C. P. Laisa, H. Vezin, M. T. Sougrati, M. L. Doublet, D. Foix, D. Gonbeau, W. Walker, A. S. Prakash, M. Ben Hassine, L. Dupont and J. M. Tarascon, Nature Mater., 2013, 12, 827–835.
2 N. Pereira, F. Badway, M. Wartelsky, S. Gunn and G. G. Amatucci, J. Electrochem. Soc., 2009, 156, A407.
3 S.-W. Kim, K.-W. Nam, D.-H. Seo, J. Hong, H. Kim, H. Gwon and K. Kang, Nano Today, 2012, 7, 168–173.

Fig. 1 First three cycles of MnO electrode cycled in LiPF6-based electrolyte.

Figure 1
Synthesis and Electrochemical Properties of Li2TMCl4 (TM=V, Cr, Fe, Mn, Co)
Authors: Vinado Carolina , Wang Shanyu , Yang Jihui 
Published: February 2020

Li-rich Li2TMCl4 system (TM = V, Cr, Fe, Mn, and Co) was studied as an alternative to LiFePO4 due to its high ionic conductivity (10-5 S/cm for Li2FeCl4 at 60°C [1]), similar theoretical capacity (165 mAh/g for 1.2 Li+ out of Li2FeCl4 vs. 170 mAh/g for 1 Li+ out of LiFePO4
[2]), and higher working voltage (3.7 V for Li2FeCl4 vs. 3.4 V for LiFePO4
[1]). These cathode materials were successfully synthesized by ball milling and solid state reaction techniques, using LiCl and TMCl2as the precursors. The phase compositions were determined by X-ray diffraction and confirmed with Rietveld refinements.
Swagelok devices were designed and built for electrochemically characterization. The cathode, a mixture of the active material, carbon black, and solid electrolyte, was consolidated with solid electrolyte using spark plasma sintering (SPS). The design of the devices and techniques were validated using standard materials, such as LiCoO2 and LiFePO4purpose., as well as EIS, CV, XRD, and galvanostatic cycling tests. The standard materials were also used to compare against the performance of the Li2TMCl4 cathode material system.

Wang, C. & Hong, J. Electrochem. Solid-State Lett.
10, A65 (2007).

Whittingham, M. S. Chem. Rev.
104, 4271–301 (2004).
Simulation and Experiments on Dendrite-Free Lithium Metal Electrode Via Surface Modification
Authors: Park Joonam , Jeong Jiseon , Lee Yunju , Byun Seoungwoo , Appiah Williams Agyei , Cho Kuk Young , Lee Young-Gi , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

Lithium metal having the lowest reduction potential (-3.04 V vs. SHE) and high specific capacity (~3800 mAh g-1) have not been successfully implemented in commercial lithium secondary batteries (LSBs) due to the formation of lithium dendrite, resulting in inhibited battery performance and instability. However, to accomplish the mileage and high energy requirements of electric vehicles and energy storage systems, the above drawbacks of lithium metal need to be solved for it to be implemented in LSBs. Hence, based on our experimental findings on the dependency of current flow on metal surface morphology, we adopted a mathematical model to simulate and optimise the metal surface morphology of different shapes to locate dendrite-free regions. To reflect the simulation results, the electrochemical performance of cells assembled with and without controlled lithium metal surface was experimentally conducted. Field-emission scanning electron microscope (FE-SEM, S-4800, Hitachi) was also used to confirm dendrite formation on lithium metal surface during charge and discharge.
The simulation results showed difference in current flow according to the different shaped patterns on the metal surface. An optimized patterned surface morphology is presented to prevent the dendrite formation. From our experimental results, we found out that cells with controlled Li metal surface morphology exhibited improved long-term cycling performance. From the FE-SEM images, the pattern holes are readily filled with liquid like and granular forms of Li-metal without any dendrite growth during the Li deposition process.

References

1. M. -H. Ryou, Y. M. Lee, Y. Lee, M. Winter and P. Bieker, Adv. Funct. Mater, 25, 825-825 (2015).
2. A. Ferrese, P. Albertus, J. Christensen and J. Newman, Journal of The Electrochemicla Society, 159, A1615-A1623 (2012).

Acknowledgements

This work was supported by the international Collaborative Energy Technology R&D Program of the Korea Institute of Energy Technology Evaluation and Planning (KETEP), granted financial resource from the Ministry of Trade, Industry & Energy, Republic of Korea. (No. 20158510050020).

Figure 1
A Series of Unique Carbon Materials for Lithium-Sulphur Batteries
Authors: Xi Kai , Kumar R Vasant 
Published: February 2020

Lithium-sulphur (Li-S) cells are attractive electrochemical energy storage systems because of the high theoretical capacity of 1675 mAh g-1of sulphur. But low active material utilization, poor cycle life and low rate performance hinder their practicality, which arising from the highly insulating nature of sulphur, the high solubility/diffusivity of lithium polysulphides in the organic electrolyte and volumetric expansion of sulphur during lithiation.
Carbon materials with high specific surface area and the porous structure are beneficial for uniform loading and distribution of sulphur in the structure to improve the reaction of sulphur in the cathode. It is important to maintain the electrical conductivity network of carbon providing envelope for lithium sulphide reduction and oxidation within a liquid solvent electrolyte without loss of fluidity, while minimising shuttling away of sulphur and avoiding or controlling the deposition of insoluble sulphides which can block the conducting paths. In addition, porous space could accommodate the volume variation of sulphur. Therefore, sulphur-carbon composites, using porous carbon have become a key research topic in Li-S batteries. Herein, the design and preparation of a series of unique carbon materials, based on metal organic framework (MOF)-derived hierarchical porous carbon, graphene-wrapped microporous carbon composite, few-layer graphene foam and carbon nanotube forest, have been demonstrated for sulphur loading to fabricate cathode structures for Li-S batteries. The improved electrochemical performance provides novel approaches to designing and fabricating long cycle life cathodes in Li-S cells.
Reference
1.
Nano Energy, 2015, 12, 538-546.
2. Nanoscale, 2014, 6, 5746-5753.
3. APL Materials, 2014, 2(12), 124109.
4. Chemical

Communications
, 2013, 49, 2192-2194.
Effects of Heat-Treatment on the Properties of Spinel LiNi0.5Mn1.5O4 Cathode Materials
Authors: Wu She-huang 
Published: February 2020

High-voltage spinel LiNi0.5Mn1.5O4 (LNMO) were synthesized by a spray pyrolysis method followed by heat treatment at 900oC for 8 hours then post annealing at 700oC for varies duration (0-96 hours) under air atmosphere. The crystalline structure and morphology of the prepared samples are studied with X-ray diffraction (XRD), neutron powder diffraction (NPD), Raman spectroscopy, scanning electron microscope (SEM), and high-resolution transmission microscope (HR-TEM). The electrochemical properties of the prepared materials had also been investigated by the studies of cyclic voltammetry (CV) and the capacity retention with coin-type cells by use of battery testing system. The results show all of the prepared samples have similar morphology and average particle size, but crystalize into mixtures of ordered P4332 and disordered Fd-3
m phases with various fractions. It can be found from Table 1 that the phase fraction of ordered phase obtained from the Rietveld refinement of NPD patterns increases with increasing duration of post annealing at 700oC. Fig. 1 manifests the results of cycling performance of the coin cells comprised with the prepared samples at 0.1 and 1.0 C rates, respectively. Samples containing the higher phase fraction of disordered phase exhibits the lower capacity fade than those dominated with ordered phase. It may be attributed to the ordered phase dominated sample experienced more complex phase change than the disordered phase dominant sample, which had been revealed from the in-situ NPD studies.

Figure 1
In Situ Tracking of the Structure Chemistry during the Synthesis of Ni-Rich Layered Oxides As High-Energy Cathodes for Lithium-Ion Batteries
Authors: Bai Jianming , Zhao Jianqing , Huq Ashfia , Zhang Wei , Wang Dawei , Wang Feng 
Published: February 2020

Ni-rich layered oxides are potential candidates for cathodes of high energy density, and meanwhile low cost and environmental benign by reducing the usage of Cobalt. To develop Ni-rich layered oxides as durable high-energy cathodes in lithium-ion batteries, construction of a solid solution in the transition metal layers by adding a second or even third cation into the LiNiO2 framework is becoming an effective strategy for stabilizing the structure and/or tailoring electrochemical properties. It has been reported that electrochemical performance is greatly affected by even a small amount of Ni-ion mixture in the Li-ion layers, and this kind of structural disorder can be controlled by improved synthetic protocols. In order to improve the electrochemical properties of the material it is critical to understand its structure chemistry during the high temperature synthesis process. Herein, we report on developing new high-capacity Ni-rich cathodes with enhanced cyclability via tuning the stoichiometry and structure of the materials. Systemic investigation is made to the phase evolution of Ni-rich LiNi1-x-yMnxCoyO2 (x+y ≤ 0.3) under different annealing temperatures by in situ synchrotron X-ray diffraction (XRD) measurements, combined with neutron diffraction and transmission electron microscopy/spectroscopy. Structural characterization indicates intriguing phase transitions during the formation of LiNi1-x-yMnxCoyO2 in the high temperature annealing process, which are closely related to cation mixture. Structure related order parameters can be used to describe these phase transitions and to determine all of the phases in such a complicated Ni-Mn-Co composition space, which, however, is challenging due to their strong dependence on the Mn and Co stoichiometry (i.e. x and y values). The in-situ XRD studies gain us access to the phase diagram in the Ni-rich region of the Ni-Mn-Co space (x+y ≤ 0.3), thereby enabling the design of synthetic protocols for preparing high-capacity LiNi1-x-yMnxCoyO2 cathodes with stabilized structure and reasonable cycling stability.
The work is supported by DOE-EERE under the Advanced Battery Materials Research (BMR) program, under Contract No. DE-SC0012704.
Binder-Less Monolithic Silicon Anodes - Enevate's HD Energy® Technology
Authors: Park Benjamin Yong 
Published: February 2020

Enevate's HD Energy® technology is a unique technology that utilizes film active material vs powder-form active material. This allows for cells with high energy density, high charge rates, as well as other unique characteristics while still being acceptably inexpensive and manufacturable. The technology involves electrodes that are silicon-dominant (>50% Si instead of being majority graphite). The unique characteristics of the technology as well as test data will be presented.
This talk will discuss the novel approach of manufacturing a film of active material that is not held together with a polymer binder. The award-winning technology (Enevate has been named a CES 2016 Innovation Awards Honoree for its unique silicon Li-ion batteries with HD-Energy® Technology in Computer Hardware & Components, Embedded Technologies, and Portable Power categories.
Enevate has developed advanced secondary Li-ion batteries based on new anode approaches which utilize silicon as the major component (vs other approaches which utilize silicon as an additive to graphite) as well as cell designs with significantly higher volumetric (25-50% increase)and gravimetric energy density. The cells which are in thinner and lighter form factors have the additional advantage of having significantly faster charging than current conventional Li-ion batteries. The ultrafast charging feature has been demonstrated to provide a 90% charge in 15 minutes (or 50% charge in just over 5 minutes) in high-energy cells.
Enevate is currently transitioning to manufacturing cells and packs that utilize its technology for its customers in the mobile electronics sector. The manufacturing approach of Enevate utilizes a global "fab-light" model where Enevate is partnering with multiple manufacturing partners while handling the manufacturing of the key component in its own factory.

Figure 1
Modeling of Conductivity of Lithium Salt in Electrolytes for Lithium-Ion Batteries
Authors: Dougassa Yvon Rodrigue , Lepage David , Rochefort Dominic 
Published: February 2020

The lithium ion battery is the most competitive power source for electric vehicles needed in the future, thus attracting extensive interest. The performance of a lithium ion battery depends to a great extent on the conductivity of electrolyte solution, because the conductivity of electrolyte solution is related to transport process and play an important role in field of lithium batteries as knowledge of the conductivity is necessary for the design of Li cells [1]. The conductivity provides also useful insights on ion solvation and association. We present in this work a comparative study on experimental values of conductivity of several formulated electrolytes (pure solvents, binary or ternary systems involving a lithium salt) with calculated values by modelling.
At first, by using different well-known equations based on Stock-Einstein, Jones-Dole and Bjerrum theories and of the solvent-solvent and solvent-salt interactions a model of conductivity ionic had been developed. The relative permittivity values of the electrolytes as well as the B- coefficients of the Jones-Dole equation for the relative viscosity of concentrated electrolyte solutions have been determined as a function of the temperature. Finally, the calculated values were then compared with experimental data of conductivity to evaluate the predictive capability of the model. Excellent agreements were obtained between calculations and experimental data electrolytes as a function of temperature with deviations up to (4 and 10) %. Results obtained by modeling during this work will guide the formulation of safer electrolytes able to improve the performances of lithium-ion batteries of lithium-ion batteries and the lifetime
[1] F.Blanchard, B. Carré, P.Willmann, D. Lemordant, Journal of power sources. 109 (2002) 203-213.
Newer Electrode Materials for Li / Na Batteries
Authors: S Gopukumar , Raman Ravikumar , Venkata Rami Reddy Boddu , Elizabeth Indu , V Selvamani 
Published: February 2020

The lithium ion battery has evolved as the major power source ever since it’s discovery in 1991 by Sony and represents one of the major successes of materials electrochemistry. Lithium ion batteries are becoming more and more popular in view of the multifarious applications arising from their high voltage and high power leading to light weight and smaller size cells/batteries. In view of the growing day to day demand for lithium ion batteries, intensive research is being pursued globally to develop new high performing cost effective electrode and electrolyte materials and importantly without compromising on environmental issues.
In this talk, we shall give an overview of the recent work being focused by tailoring the carbon materials for developing high performing anode materials based on viz., reduced graphitic oxide (rGO), graphene nano structures (GNS), multi-walled carbon nanotubes (MCNT), Bioderived and cathode materials under the national solar mission programme of CSIR. Normally, graphite powders are employed as anode materials but we demonstrate a new type of lithium ion battery replacing the conventional graphite powder coated on to a copper foil which exhibits high performance even at high rates (2C) when cycled between 2.9 and 4.1V and finds applications in Solar Lanterns etc. These cells could be charged by solar energy. Furthermore, possible use of Sodium (Na) as an alternative to Lithium will also be highlighted.
Determination of Radial Thermal Conductivity and Specific Heat in Externally-Heated LiCoO2 cells
Authors: Mazurick Ryan , Brandon Andrew , Spinner Neil , Tuttle Steven G 
Published: February 2020

In this presentation, we will investigate the thermophysical properties of LiCoO2 18650 battery cells. Due to their versatility and high energy density, lithium-ion batteries have become a major power source in a number of consumer and industrial products over the last decade. As their popularity and number of applications increase, so do instances of catastrophic battery failure. Excessive external heating, which in turn leads to thermal runaway, is a principle cause of cell failure and failure events continue to occur despite the installation of safety features, such as vents and thermal fuses, within the cells. Models of cell failure do exist and they have been used to improve upon battery safety features; however, failure models require prior knowledge of the cell’s thermophysical properties.
For many common, commercial lithium-ion batteries, LiCoO2 18650 cells included, knowledge of their thermophysical properties is often either incomplete or absent entirely. To determine the radial thermal conductivity and specific heat of a LiCoO2 18650 cell, we conducted external heating experiments and created a numerical heat transfer model. In our experiments, a thermocouple and a heat flux sensor were mounted to the battery surface and, without damaging the cell, external heat was provided using NiCr wire, wrapped helically around the cell’s exterior. Using the time-dependent heat flux data measured at the battery’s surface, our computational model solved the heat conduction equation for the cell’s radial temperature profile. The radial thermal conductivity and specific heat of the LiCoO2 18650 cell were then found by minimizing the difference between the experimental surface temperature data and the model’s predicted surface temperature over time. Matching the model’s results with the experimental data was achieved with a parametric exploration of specific heat values and the Secant Method, which iterated over the radial thermal conductivity. Over the course of our presentation, the experimental setup, the numerical model, and the results we obtained will be explored in detail. We will also discuss how this method can be used to study the radial thermal conductivity and specific heat of any cylindrical cell.
Pseudo-Contact Shift in Periodic Paramagnetic Solids Via Density Functional Theory
Authors: Pigliapochi Roberta , Pell Andrew , Ceresoli Davide , Kaupp Martin , Grey Clare P. 
Published: February 2020

Nuclear Magnetic Resonance (NMR) spectroscopy of paramagnetic solids represents an exceptional means for getting insight into structural and electronic properties of the systems, giving on the other hand a particularly involved response to analyse. Specifically, the overall isotropic shift is given by a combination of the Fermi contact term, dependent on the electronic structure of the paramagnetic site and on the strength and covalency of its bond with the observed centre, and on the pseudo-contact term, a relativistic dipolar contribution that gives information regarding the structure and the spatial arrangements of the sites in the system. In this work we present a protocol to extend the computation of the paramagnetic shielding in the presence of spin-orbit coupling towards solid systems, with which to calculate these two contributions explicitly via periodic solid-state Density Functional Theory (DFT) so to unravel detailed information hidden in the NMR spectrum. We describe how the involved properties such as g- and hyperfine tensors behave in paramagnetic solids where the spin-bearing ions are a major constituent of the crystal lattice. Finally it is clarified how to combine these quantities in order to separate the various terms contributing to the paramagnetic shielding, σs
: this method enables to get deeper insight into the overall isotropic shift and shift anisotropy observed experimentally, and to identify information regarding electronic structure and geometry of the system. The method is applied to a series of solid-state LiTMPO4 (with TM=Mn, Fe, Co and Ni) powders and the corresponding 7Li and 31P NMR shifts are computed. From these results we outline differences in the extent of spin-orbit coupling effects and electron-nuclear magnetic interaction, and the various tensorial products are combined together to explicitly calculate all the terms involved in the description of σs
. A detailed comparison is presented between contact and dipolar interactions within the same system and across the series, to untangle the dual nature of the overall isotropic shift and shift anisotropy.