bluuebunny/crossref_metadata_2025_split huggingface dataset:
A Novel Surface Modified Nano-Silicon As Promising Anode Material Lithium-Ion Batteries
Authors: Han Joong-Hee , Hayati-Roodbari Nastaran , Elsaesser Michael S , Schodl Juergen , Gavrilovic Wohlmuther Aleksandra , Hans Philipp , Hradil Klaudia 
Published: February 2020

Silicon has been considered as one of the most promising anode materials for LIBs in order to replace the conventional anode material (graphite). Investigations of the Li-Si binary system indicated at least theoretically, the highest specific capacity (4200 mAh/g), during the electrochemical lithium alloying (Li4.4Si) of silicon with lithium ions. Unfortunately, Si shows a very low mechanical elasticity during the battery cycling (lithiation/delithiation), which causes a contact loss in the electrode and subsequently lead to a shorter cycle life and finally fast capacity fading. This is the major drawback of Si as an anode material and the reason why a general distribution within the lithium ion battery market couldn´t be established up to now.
The first idea proposed to overcome this shortcoming, is a new approach concerning the binder materials. In the research of energy storage materials, a new technology named biomimetics has been adapted to breakthrough the serious technical problem. The use of bioinspired binders for the silicon anode materials represents one basic approach of our present study. Namely, potato starch, gelatine and alginic acid from brown algae were studied as a binder. It was found that the potato starch was the best binder, exhibiting 1500 mAh/g at the 20thcycle. This is due to the fact that amylopectin polysaccharides suppress the volume change of silicon and form a beneficial SEI film on the electrode during cycling.
The second idea proposed in this work is based on the formation of a nanoscale, 3D-connected mesoporous silicon by a magnesiothermic reduction process, providing short diffusion pathways for the lithium ions during lithiation / delithiation. The silicon-based cells were characterized by electrochemical investigations and the first results show that the mesoporous silicon-based cell exhibits a discharge capacity of 1200 mAh/g and a coulombic efficiency of 84% after the cycling precondition with 0.05C. The improvement of the electrical conductivity and the modification of the surface´s electrochemical properties is achieved by an adaption of a coating method, known as substrate-induced coagulation. The coating materials are distinguished between lithium reactive and nonreactive. Further, they can be subdivided, i.e. carbonaceous materials (nano-graphite, graphene), nano metals (Cu, Ni) and nano metal oxides [TiO2, In(OH)3, ITO(indium tin oxide)].
Investigation of LiMn2O4-Li2NiF4 Solid Solutions As Electrode Materials for Lithium-Ion Batteries
Authors: Yi Tanghong , Kim Chunjoong , Plews Michael Rhys , Cabana Jordi 
Published: February 2020

Lithium ion batteries play a very important role in consumer electronics as the component where energy stored. However, today’s lithium ion batteries are not suitable for widespread application in electric vehicles due to the high cost required to achieve desired levels of energy density and life.1 Improvements in energy density (cell voltage and/or storage capacity) are still sought for these applications. Given the high capacity of graphite-based negative electrodes, the focus is placed on increasing performance at the positive electrode. Today, the most popular positive electrode materials are layered LiMO2 (M = Co, Mn, Ni), spinel LiM
2O4 (M = Mn, Ni), and olivine LiMPO4 (M = Fe, Co, Mn).2, 3 LiM
2O4 and its derivatives are widely used in current electric vehicles mainly because of their robust framework with fast ionic diffusion and low cost. In this work, we explore the possibility of raising their voltage of operation by incorporating Li2NiF4 into the LiMn2O4 lattice to form a solid solution of LiMn2O4-Li2NiF4 by taking the advantage of their structural similarity. The reaction between the two components is complex. Apart from single phase samples, core-shell structures could also be obtained by varying the ratio of two components as well as reaction duration. An example of this competition is provided by LiMn2O4-20% Li2NiF4, as shown by the different elemental distributions from energy dispersive spectroscopy (EDS) elemental maps in Figure 1, indicating solid solution and core-shell structures, respectively. The local chemical environment change of oxygen, fluorine and transition metals has been investigated by X-ray absorption spectroscopy. The electrochemical performance of the phase-pure LiMn2O4-Li2NiF4solid solutions will also be presented.
ADDIN EN.REFLIST 1. R. V. Noorden, Nature,
50726-28 (2014).
2. J. M. Tarascon and M. Armand, Nature,
414359-367 (2001).
3. B. L. Ellis, K. T. Lee, and L. F. Nazar, Chem. Mater.,
22691-714 (2010).

Figure 1
Improved Electrochemical Performances and Thermal Stability of LiNi0.6Co0.2Mn0.2 by Li3PO4 coating
Authors: Lee Suk Woo , Kim Myeongseong , Kim Kwang-Bum 
Published: February 2020

LiCoO2 is the most commercialized in lithium ion batteries (LIBs) for portable electronics because of its high volumetric energy density compared to the other commercialized cathode materials. However, low specific capacity (145 mAh/g @ 4.3 V cut-off) hinders its application to emerging technologies, such as power tool and plug-in hybrid electric vehicles. As a result, layered Ni-rich LiNixCoyMn1
-
x
-
yO2 materials have attracted much attention as promising alternative cathode materials because of their high capacity and relatively low cost. However, Ni-rich layered cathode materials suffer from structural instability by direct contact with electrolyte at high voltage (>4.3V), resulting in poor cyclability, rate capability and thermal instability. To solve these problems, a lot of researches have been carried out to coat the surface of layered cathode materials using oxide or phosphate, such as TiO2, Al2O3, and Li3PO4.
Among these coating materials, Li3PO4 has attracted a great attention as coating material due to its high ionic conductivity and thermal stability due to strong P=O bonding. Recently, Zhao et al., reported on the Li3PO4 coating on LiFePO4 cathode material, but they used Li3PO4 nano particle as a coating material, resulting in non-uniform coating. Also, Xiong et el, tried to coat the Li3PO4 on LiNi0.8Co0.1Mn0.1O2 cathode material using the reaction between (NH4)2HPO4 and lithium residues, but the Li3PO4 coating layer is not confirmed.
In this study, we report on the synthesis of Li3PO4-coated LiNi0.6Co0.2Mn0.2O2 using a citric acid assisted sol-gel method in which nm-thick Li3PO4 layer was uniformly coated on the LiNi0.6Co0.2Mn0.2O2. It exhibited improved cyclability at high voltage (4.7V) and rate capability than those of bare LiNi0.6Co0.2Mn0.2O2. In addition, Li3PO4-coated LiNi0.6Co0.2Mn0.2O2 showed improved thermal stability at elevated temperature.
More details on the synthetic procedure, electrochemical and physical properties will be presented at the meeting.
Effects of Fast Charging on Lithium-Ion Cells
Authors: Somerville Limhi , Jennings Paul , McGordon Andrew , Lyness Christopher , Prezas Panagiotis , Basco John , Bareno Javier , Duong Tien , Bloom Ira 
Published: February 2020

As electrified vehicles become widely accepted, consumers expect the characteristics to be similar to those with a conventional, internal-combustion engine. Among these is the ability to ‘refuel’ quickly. For example, current lithium-ion battery technology takes an hour or more to recharge (refuel) whereas a conventional car can take 5 minutes or less. Some work has been does to understand the electrical effect fast charging lithium-ion cells has. However, no one understands what faster charging does to internal cell components.
We cycled commercially-available 18650 cells at four different charge C-rates (0.7, 2, 4, 6) and two different charge-returned windows (40% and 100%); the discharge rate was C/3. The cells were opened and both electrodes as well as separator were analysed in an argon-environment glove box using a range of surface-sensitive, analytical techniques.
The binder material at the negative electrode decomposed at higher C-rates causing delamination from the copper current collector. Surprisingly, cells cycled within a smaller charge-returned window completely delaminated irrespective of C-rate, suggesting there are at least two different mechanisms responsible for electrode delamination in the cells.
Analysis of surface film chemistry and thickness showed a dependence on C-rate. Cells cycled at higher C-rates had a thicker surface film and a more complex chemistry. Gel permeation - liquid chromatography showed that the surface film of the cells was extremely complex, with a large range of molecular weights (MW). As the C-rate increased, the average MW of the oligomers from the surface film also increased.
These findings indicate that an increased charging rate affects the negative electrodes surface film and its adhesion to the current collector. Although a smaller SoC window caused less resistance increase and capacity losses in 18650 cells it was detrimental to the lamination properties. This could have significant implications for unconstrained pouch cells.
Anisotropic Mechanical Deformation of Lithium-Ion Electrode Networks Using Reconstructed Microstructures
Authors: Mendoza Hector , Roberts Scott A. , Brunini Victor E. , Long Kevin N. , Grillet Anne M. 
Published: February 2020

Lithium-ion batteries are attractive for consumer electronics because of their high energy density, low self-discharge rates, and no memory effect. However, like all rechargeable batteries, lithium-ion batteries suffer from capacity fade. Understanding the mechanisms that lead to capacity fade in lithium-ion batteries is crucial for the advancement of lithium-ion battery technologies and the electronics relying on them for operation. We hypothesize that one of the mechanisms leading to capacity fade arises due to mechanical stresses and changes to the connectivity of the electron transport network, which results from lithium intercalation reactions as batteries are cycled through charges and discharges. Based on our hypothesis, we analyze these changes to the network structure by performing three-dimensional simulations of the particles at the mesoscale using reconstructed microstructures from SEM/EDS images of actual electrode particles. We model the anisotropic swelling using coupled multi-physics simulations with a finite element code that encompasses mechanical, electrochemical, species transport, and thermal effects. By incorporating all the aforementioned effects into our model, we hope to provide insight on how degradation of lithium-ion batteries evolves as a result of changes in the electron transport network arising from swelling, deformation, and stress generation driven by lithium intercalation.
High Capacity and High Density Sio Anode for High-Energy Lithium-Ion Batteries
Authors: Yuca Neslihan , Zhao Hui , Zheng Ziyan , Battaglia Vince , Zaghib Karim , Liu Gao 
Published: February 2020

High capacity and high density functional conductive polymer binder/SiO electrodes are fabricated and calendered to various porosities. The effect of calendering is investigated to the reduction of thickness and porosity, as well as the increase of density. SiO particle size
remains unchanged after calendaring. When compressed to an appropriate density, an improved cycling performance and increased energy density are shown compared to the uncalendered electrode and over-calendered electrode. The calendered electrode has a highdensity
of ~1.2 g/cm3. A high loading electrode with an areal capacity of ~3.5 mAh/cm2 at a C/10 rate is achieved using functional conductive polymer binder and simple and effective calendaring method.

Figure 1
Towards a Better Reversibility of the Electrochemical Li-Si Reaction through the Use of Partially Oxidized Silicon Particles and Alternative Electrolyte Salt/Additives
Authors: Touidijine Amina , Morcrette Mathieu , Courty Matthieu , Davoisne Carine , Lejeune Michael , Mariage Nicolas , Porcher Willy , Larcher Dominique 
Published: February 2020

Silicon is one of the most promising candidates as anode material for Li-ion batteries because it offers the largest gravimetric and volumetric capacities
[1]
. However, the most challenging problem associated with the Li-Si reaction is the drastic particles swelling (up to + 300% in volume) which results in degradation of the electrode cohesion and in capacity loss upon cycling
[2]
. Accordingly, the choice of the binder is crucial as it dictates most of the performances of the Si-based electrode
[3]
and also drives the nature of the solvent used to dissolve it. CMC (Carboxy-Methyl-Cellulose) is known to be a very efficient binder to maintain electronic percolation and mechanical integrity of Si-based electrodes
[4]

. Also, CMC is water soluble hence environment friendly compared to other polymeric binders that could necessitate hazardous solvents, such as NMP.
However, the large-scale production of Si/CMC/C composite electrode is troublesome since it generally leads to a large H2 bubbling within the slurry, later making impossible the fabrication of uniform electrodes. This results from the oxidation of Si by water (Si + 2H2O à SiO2 + 2H2), and we will here show how we mastered and finally avoided this reaction through partial and controlled oxidation of Si by pre-reaction with either water (Siwater) or air at moderated temperatures (Siair).
By coupling volumetric, chemical, XRD, TEM/EELS, TGA/DSC, IR and gas adsorption data, the texture and chemistry of the resulting silica-based coating layers were found to be highly dependent on the oxidation path (Figure 1), while the level of oxidation is tuned by the time-temperature of the treatment. Although fully oxidized samples are totally inactive vs. Li., a mild oxidation (e.g. 10-15wt% SiO2) protects the Si core from water during the electrode processing, while ensuring very stable capacity upon extended cycling (Figure 2).
The electrochemical properties of the various resulting oxidized materials will be here deeply discussed. In addition, we will describe the effects of 1) alternative salts (LiPF6 and LiTDI), 2) various additives (FEC and VC), and 3) different procedures for the electrode making (e.g. powder mixing, drying conditions) onto the reaction of these Si/SiO2composite materials with Li.
[1] G. C. L. B.A. Boukamp, and R.A Huggins, J. Electrochem. Soc: Electrochem Sicence and Thechnology
1981, 128, 725-729.
[2] U. Kasavajjula, C. Wang and A. J. Appleby, Journal of Power Sources
2007, 163, 1003-1039.
[3] N. S. Hochgatterer, M. R. Schweiger, S. Koller, P. R. Raimann, T. Wöhrle, C. Wurm and M. Winter, Electrochemical and Solid-State Letters
2008, 11, A76.
[4] B. Lestriez, S. Bahri, I. Sandu, L. Roue and D. Guyomard, Electrochemistry Communications
2007, 9, 2801-2806.

Figure 1
High Energy and Power Density TiO2 Nanotube Electrodes By Conformal Electrodeposition of Polymer Electrolyte
Authors: Djenizian Thierry , Plylahan Nareerat 
Published: February 2020

Due to high surface area and improved charge transport, self-supported nanostructured materials based on transition metal oxides can be used as electrode for Li-ion batteries (LIBs). Their use is particularly interesting when considering the miniaturization of energy storage systems and the development of micropower sources [1]. For example, it has been reported that self-organized titania nanotubes (TiO2NTs) are potential candidates as negative 3D self-supported electrodes for Li-ion microbatteries [2]. In the prospect of developing all-solid-state batteries, it has been also demonstrated that electrodeposition technique (EDP) is a viable approach to achieve the deposition of polymer electrolytes on nanostructured electrode materials [3,4].
In this work, we study the conformal electrodeposition of PMMA-(PEO)5 copolymer on TiO2NTs by electrochemical techniques. The physical and chemical analyses of the electrodeposited polymer carried out by SEM, TEM, XPS, TGA, and NMR will be discussed in order to understand the relationship existing between the EDP parameters and the properties of the polymers.
Then, the benefits of the conformal coating of polymer electrolyte on the electrochemical performance in terms of energy density and power density will be highlighted. Actually, due to better electrode/electrolyte interface, we show that the capacity of the half cell is improved by 45% at 1 C compared to bare TiO2NTs (Fig. 1). Furthermore, we report that the polymer-coated TiO2nts tested in the full cell deliver an average capacity of ∼30 μA h cm−2 (120 mA h g−1) with LiNi0.5M1.5O4, ∼25 μA h cm−2 (100 mA h g−1) with LiFePO4 and ∼23 μA h cm−2 (90 mA h g−1) with LiCoO2, respectively during 50 cycles (Fig. 2).
References
1. B. L. Ellis, P. Knauth, and T. Djenizian, Adv. Mater, 26, 3368, (2014).
2. T. Djenizian, I. Hanzu, P. Knauth, J. Mater. Chem., 21, 9925, (2011).
3. N. A. Kyeremateng, F. Dumur, P. Knauth, B. Pecquenard, and T. Djenizian, Electrochem. Commun., 13, 894 (2011).
4. N. Plylahan, N.A. Kyeremateng, M. Eyraud, F. Dumur, H. Martinez, L. Santinacci, P. Knauth, T. Djenizian, Nanoscale Res. Lett., 7, 349, (2012).

Figure 1
Polymer-Assisted Solution Method to Metal Oxide Network Structures for Lithium-Ion Battery Electrodes
Authors: Luo Hongmei 
Published: February 2020

Rechargeable lithium-ion batteries have been extensively investigated for their promising application in hybrid electric vehicles because of their high energy and power densities and long cycle lifetime. A great effort has been made to synthesize a variety of electrode materials to improve the energy density, rate capability, and cycling stability. Nanostructured materials have received much attention as electrodes due to the short transport lengths for both electrons and lithium ions, higher electrode-electrode contact area, and better accommodation of the strain of lithium insertion/extraction.
Here we report a facile polymer-assisted chemical solution method to grow cobalt oxide, nickel oxide, bismuth oxide, and vanadium oxide network structures for lithium-ion battery anodes and cathodes. The carbon left from the decomposition of polymers is an effective binder between metal oxides and the nickel foam. As compared to the metal oxide powders prepared in a conventional way by using polymer binder and carbon black, these one-step direct growth electrodes showed much better lithium storage properties with high capacities, stable cyclability, and rate capability. For example cobalt oxides on nickel foam gave a capacity of 900 mAh/g at a current density of 1 A/g and 600 mAh/g at 4 A/g. The good performances of these electrodes could be attributed to intimate contact between the active material and the nickel foam, the porosity of the current collector, and the network structure of the active materials.
Probing Ionic Transport in a Lithiated Carbon Anode with Electrochemical Strain Microscopy
Authors: Wang Peiqi , Li Jiangyu 
Published: February 2020

Lithium ion batteries are the most widely used energy storage device in both portable electronics and electric vehicles due to its high energy density. However, there are still remaining issues unsolved. To further improve the Li-ion battery performance, it’s important to understand the lithium ion intercalation/de-intercalation process upon cycling. The development of a new scanning probe microscopy technique (SPM), electrochemical strain microscopy (ESM), in which a combination of AC bias and DC bias is applied to the sample surface, allows us to evaluate mobile ionic diffusivity and electrochemical reactivity on the nanoscale.
In this work, we will first discuss about using a series of strain-based SPM techniques to distinguish different microscopic mechanisms including electromechanical coupling, spontaneous polarization, induced dipole moment and electrostatics. Then we will demonstrate the localized probing of lithium ion transport property in a lithiated carbon anode using ESM. Pristine carbon anode is also studied as comparison. Also, we’ll investigate the lithium ion transport through the solid electrolyte interface (SEI) layer, which is formed on the carbon anode surface upon cycling.
Influence of Lithium Precursors and Calcination Atmospheres on Graphene Sheets-Modified Nano-Li4Ti5O12 Anode Material
Authors: Yuan Tao , Li Wenting , Zhang Weimin , Ma Jingjing , He Yu-Shi , Liao Xiao-Zhen , Ma Zi-Feng 
Published: February 2020

With the advantageous features include suitable lithium insertion position and "zero strain" structure, Li4Ti5O12 has become one of the ideal anode materials for lithium-ion battery and battery-capacitor system. However, the obstacle of its poor electronic and Li+ conductivity restrict its rate capacity. Many researches proved that the one-pot preparation process, which is mixing the carbon precursor with lithium and titanium precursor and then thermal treating in an inert or reducing atmosphere together, not only can form a carbon coating layer to improve the electronic property of the materials easily, but also inhibits the particle size growth of LTO by a barrier effect of carbon. Among kinds of carbon source, graphene presents excellent unique properties, which has been considered as an ideal carbon source to improve the electrochemical performance of LTO and many other active materials. However, the intersheet π-π attractions of GS easily resulted in its restacking and agglomeration. Therefore, an oxygenated graphene (GO) with a special amphiphilic molecular structure is adopted as GS precursor to prepare GS modified composites. Due to the amphiphilic characteristic of GO, the choice of an appropriate Li precursor is extremely important to obtain a high quality product.
In this study, we systematically investigated the influence of lithium precursor and calcination atmosphere on the reaction mechanisms, phase formation, particulate morphology, surface properties and electrochemical performance of graphene sheets-modified nano-Li4Ti5O12 composite. The results shown that the lithium precursor containing carboxyl anion such as LiAc and Li2CO3 would connect with oxygen groups of GO by strong hydrogen bonds to restrict the morphology of composites and the phase formation of pure spinel Li4Ti5O12. Furthermore, the oxygen ratio in the molecular structure of lithium compound is proportional to the consumption of graphene. In addition, the reducing atmosphere facilitates the partial reduction of Ti4+ to promote the interfacial charge transfer kinetics of the product.
Through optimization the conditions of the reaction, the sample adopting LiOH precursor with adjustment GS ratio calcined under Ar/H2 (5 %) atmosphere delivers 172.8 mAh g-1 at 1 C and maintained a discharge capacity of 98.0 mAh g-1 at a high rate of 40 C. This sample also showed fairly stable cycling performance. After 800 deep cycles at a high charge/discharge rate of 40 C, the capacity can hold 97.7 % of its second discharge value. This study not only provides an optimization of Li precursor and calcination condition for GS modified LTO material, but also has significant reference value for any combination reaction with GO participation.