bluuebunny/crossref_metadata_2025_split huggingface dataset:
Polydopamine-Coated Current Collector: Improving the Electrochemical Performance of Si Anode By Raising the Interfacial Adhesion Strength
Authors: Kong Seokhyeon , Cho Inseong , Hwang Suyeon , Ryou Myung-Hyun , Lee Yong Min 
Published: February 2020

The high theoretical capacity of Si has made it a promising candidate for high energy density and large-scale lithium ion battery (LIB) anode. However, this system exhibits rapid capacity decay and hence poor cycling performance due to huge volume expansion of about 300% when Li-ion inserts into the Si particle during charging. Experimental observations suggest the formation of cracks at the early stages of cycling due to this volume expansion. The continuous mechanical stressing and fracturing of Si particles lead to the pulverization of the electrode and formation of dead Si particles. In particular, dead particles detached from current collector can mainly occur decay of electrochemical performance of lithium ion batteries.[1,2]

Hence, we tried to improve the interfacial adhesion between the Si electrode layer and the current collector by making a hydrophilic layer on the current collector through polydopamine coating and induce cross-linking of polydopamine (PD) and polyacrylic acid (PAA) binder. The contact angle and the interfacial adhesion between the electrode and the PD coated and bare current collector were analyzed using Phoenix 300 Touch and the Surface And Interfacial Cutting Analysis System(SAICAS), respectively.
From the SAICAS analysis, the adhesion strength between PD-coated current collector and Si electrode layer was improved comparing to the bare system. (Bare current collector: 0.2455 kN m-1 and PD-coated current collector: 0.3532kN m-1). The PD-coated current collector showed a higher hydrophilicity to the electrolyte than the bare current collector. The cycle performance of the cell was greatly enhanced by the PD coating on the anode current collector. The present studies suggest that, the coating of PD and induced cross-linking of PD and PAA improves the electrochemical performance of the Si anode.

Acknowledgement

This work was supported by the Human Resource Training Program for Regional Innovation and Creativity through the Ministry of Education and National Research Foundation of Korea(NRF-2014H1C1A1066977)

References

1. J. Choi, M.-H. Ryou, Y. M. LEE, Journal of Power Sources 252 (2014) 138-143
2. J. Choi, K. Kim, M.-H. Ryou, Y. M. LEE ACS Appl. Mater. Interfaces 2015, 7, 14851−14858
Lithium Ion Thin-Film Electrodes for All-Solid-State and Electrochromic Applications
Authors: Röder Manuel , Posset Uwe , Buensow Johanna , Guntow Uwe , Lorrmann Henning , Guerfi Abdelbast , Zaghib Karim , Sextl Gerhard 
Published: February 2020

Establishing thin-film technologies for lithium ion batteries is an important step towards all-solid-state batteries. Solid thin-film electrodes expose significantly higher charge and discharge rates than standard composite electrodes, thus have the potential to increase the power density of thin-film batteries.
Sol-gel procedures are established in battery research for synthesizing active material powders with controlled particle sizes. Here, we prepared single- and multi-layer films of active materials viadip-coating method. Both electrode single-layer systems exhibit excellent electrochemical properties such as high reversibility and low polarization in long-term CV measurements and show almost full capacity retention at charge and discharge currents up to 100 C.
Furthermore, applied on transparent conducting oxides, the electrodes were of high optical quality and showed intense color changes upon charging and discharging which positions them as interesting electrochromic compounds. Both materials are well known for their high reversibility and low cost compared to commonly known electrochromic metal oxides such as tungsten oxide.
The combination of their highly stable and very fast cycling capabilities with their color switching properties, make the presented transparent thin film electrodes promising candidates for high-power all-solid-state and electrochromic applications.
This paper shows transparent Li4Ti5O12 and LiMn2O4 thin film electrodes characterized by the above mentioned electrochemical measurements and their optical properties with the help of UV-vis spectroscopy. Additionally, material characterization is demonstrated via X-ray diffraction, XPS and SEM imaging.

Figure 1
Doped Li2CuO2 Cathode for Li Ion Batteries
Authors: Ramos-Sánchez Guadalupe , Romero-Ibarra Issis , Vazquez-Arenas J. , Galvan Marcelo Enrique , González I. 
Published: February 2020

Li ion batteries is one of the emerging technologies that might have a broad use in electric and hybrid vehicles; however, it is of primordial importance to formulate high capacity electrodes obtained from readily available sources. Lithium cuprates have been studied for more than twenty years, the reason being is the high theoretical capacity (490 mAh/g) which is much higher than that of the largely used cathode materials LiCoO2 and LiFePO4. The structural transitions from Li2CuO2 to CuO2 upon delithiation (charging) and then to LiCuO2 and Li2CuO2 upon discharge are very dramatic leading to loss capacity on the very first charging cycle. To the date no reports have been published on the maximum capacity that can be reached with Li2CuO2 as function of electrode preparation variables, the potential window for charge/discharge and C-rate. The determination of the maximum capacity at several conditions is of primordial importance in order to propose possible niche applications and alternative routes to improve the reversibility of the system. We have found that the preparation under inert atmosphere is of primordial importance in order to enhance the capacity, since the mixing, coating and drying under air atmosphere accelerate the transformation of Li2CuO2 to LiO2 and CuO2i n the lapse of minutes. Moreover the electrode calendaring process (usually carried out on air) diminishes the maximum capacity on the first cycle and leads to the reduction to the capacity up to 20 mAh/g during the first ten cycles at a C/15 rate and in the range of 1.5-4.3 V (Li+/Li0). On the other hand if the calendaring process is replaced by pressing at 6 ton/cm2 the capacity after ten cycles is as high as 150 mAh/g at C/15. However, in order to obtain stable capacity up to 100 cyles, the operation potentials should be diminished from 1.5-4.3 V to 2.2-3.8 V (Li+/Li0), in this situation 100 mAh/g are obtained after 100 cycles suffering no affectation on the structural stability of the material. Further modification on the synthesis by Co, Mg and Fe doping are being under study, preliminary results indicate that the insertion of the ions between the layer of Li2CuO2 improve the reversibility, enhancing the capacity up to 10% of the value of maximum value obtained with pure Li2CuO2.
Battery Cost Reduction through Design of a Multi-Chemistry Pack
Authors: Aryanpour Masoud , Ashcraft Robert , Miara Lincoln J. 
Published: February 2020

In recent years, there has been an enormous drive to develop fully or hybrid electric cars by taking advantage of novel secondary batteries, and in particular, of Li-based battery technologies. Realization of a fully electric vehicle (EV), nonetheless, requires overcoming big challenges that demand much larger energy densities, simultaneously with much higher rate (power) capabilities [1].
Current efforts try to address those challenges by focusing on two main roadmaps: 1) Materials, that is, optimizing current or inventing new chemistries [2, 3], and 2) Battery Management and mathematical modeling [4, 5], that is, optimizing the usage of current chemistries through various strategies that would adapt charge/discharge cycling properties.
In addition, there are prior or current works that try to take advantage of different available chemistries, which although promising, lack a clear roadmap for fully utilizing available technologies.
Hereby, we introduce a clear roadmap/method for 1) determining the areas of benefit of, and 2) designing of a “multi-chemistry battery pack” that would perform better than any “single-chemistry packs”. In simple terms, we show how to determine when a multi-chemistry pack can beat its constituent single-chemistries, and how to design/utilize different chemistries in hybrid pack whenever the hybrid combination is more beneficial.
REFERENCES
[1] By panel reporters of National Research Council, “Overcoming Barriers to Deployment of Plug-in Electric Vehicles”, The (U.S.) National Academies of Sciences, Engineering, and Medicine, 2015.
[2] J.-M. Tarascon and M. Armand, “review article Issues and challenges facing rechargeable lithium batteries”, Nature, 414, 359-367, 2001
[3] J.B. Goodenough and Y.S. Kim, “Challenges for Rechargeable Li Batteries”, Chemistry of Materials, 22 (3), 587–603, 2010
[4] M.F.M. Sabri, K.A. Danapalasingam, and M.F. Rahmat, “A review on hybrid electric vehicles architecture and energy management strategies”, Renewable and Sustainable Energy Reviews, 53, 1433-1442, 2016
[5] A. Fotohi, D.J. Auger, K. Propp, S. Longo, and M. Wild, “A review on electric vehicle battery modelling: From Lithium-ion toward Lithium–Sulphur”, Renewable and Sustainable Energy Reviews, 56, 1008–1021, 2016
Evaluation of Different Separators By Using 18650 Li-Ion Cells
Authors: Song Wen feng , Zhang Ya li , Deng Zhong yi , Carlson Steve A 
Published: February 2020

Safety and performance characteristics are mainly correlated with electrode materials, electrolytes and separators. The presentation will outline many key functions that the separator serves in lithium-ion batteries and describes a separator design – specifically, AlOOH-based nanocomposite membranes – which addresses several critical safety concerns for high performance lithium-ion batteries.
Boehmite(γ-AlOOH) separator, polypropylene(PP) separator and boehmite-PP separator 18650 Li-ion cells have been made, The safety performance of the different separator 18650 Li-ion cells have been investigated, especially by nail penetration which is well known to be the most difficult safety test for high energy density including NMC/NMA positive material 18650 cells and passing this test is critical for xEV applications in China.
The preliminary results show that the cycling performance of boehmite separator cells was better than the other two kinds of separator cells. Cells using boehmite separator showed improved nail penetration performance compared with PP separator cells, which may be attributed to the excellent thermal stability of the boehmite separator. More safety test results and cycling performance data of all three different separator cells will be further discussed in this presentation.
Hybridizing Organic and Solid State Single-Ion Conductors: Thermotropic Ionic Liquid Crystals for Lithium Battery Electrolytes
Authors: Bresser Dominic , Leclere Mélody , Bernard Laurent , Rannou Patrice , Mendil-Jakani Hakima , Lyonnard Sandrine , Picard Lionel 
Published: February 2020

The continuously increasing importance of lithium-ion batteries for the transportation sector does and will require also substantial enhancements of their energy and power density as well as their safety. As the latter aspect is mainly determined by the currently utilized liquid organic electrolytes, comprising LiPF6 as conducting salt, extensive research efforts are directed towards the development and optimization of alternative (solid) electrolytes.1–3 In addition to a suitable ionic conductivity, these new electrolyte systems have to fulfill a series of other requirements, most importantly, a sufficient electrochemical stability, beneficial interfacial properties, enhanced thermal stability, and, preferably, flexibility as well as single-ion conductivity to avoid the necessity of using LiPF6 and detrimental cell polarization. The two electrolyte systems, which are currently considered most promising to realize safer lithium-based batteries, are basically solid ceramic and polymer-based electrolytes.1–3 However, while the former frequently suffer electrode/electrolyte interfacial instability and thus rapid capacity fading (apart from its intrinsic rigidity), the latter commonly face challenges regarding their thermal stability and large cell polarization due to the necessity of adding a conducting salt to the polymer matrix.
In an attempt to combine the beneficial characteristics of these two systems, we designed and synthesized a completely new electrolyte system: single-ion conducting thermotropic liquid crystals (TILCs, Figure 1). These TILCs reveal self-assembling, homeotropically aligned, lamellar nanostructures, providing confined ionic nanochannels for reversible lithium ion transport across suitable electrode/electrolyte interfaces. Herein, we will report their extended characterization as lithium battery electrolytes with a particular focus on the structure to transport interplay, highlighting the importance of large-scale facility experiments (structure and dynamics) to finally unveil and understand the ion transport mechanism on the molecular and sub-molecular level.

Figure 1. General chemical formula of TILCs.

References

1. B. Scrosati and J. Garche, J. Power Sources, 195, 2419–2430 (2010).
2. J. Kalhoff, G. G. Eshetu, D. Bresser, and S. Passerini, ChemSusChem, 8, 2154–2175 (2015).
3. Y. Wang and W.-H. Zhong, ChemElectroChem, 2, 22–36 (2015).

Figure 1
Recent Developments in Garnet-Type Solid State Electrolyte Thin-Films Grown By CO2-Laser Assisted Chemical Vapor Deposition
Authors: Loho Christoph , Djenadic Ruzica , Clemens Oliver , Hahn Horst 
Published: February 2020

The research on solid state electrolytes (SSE) is motivated by their excellent safety properties, their potential for battery miniaturization, and their possibility to enhance the energy density of the battery. However, their often low Li-ion conductivity compared to liquid electrolytes is a drawback. In this respect garnet-type Li7La3Zr2O12 (LLZO) attracted much attention, since it combines features such as a very good electrochemical stability over a wide potential range as well as against lithium metal and a reasonably high Li-ion conductivity of around 10-6 S·cm-1 in tetragonal and 10-4 S·cm-1 in cubic modification.[1]

Regarding fabrication, chemical vapor deposition (CVD) is a suitable method to grow functional thin-films for Li-ion batteries, since it allows for a homogeneous growth over large areas with high deposition rates and a very high purity.[2] Despite these advantages, reports on CVD grown thin-films for Li-ion battery application are rare. One reason may be that with conventional CVD precursor delivery systems it is often difficult to achieve the correct composition of complex, multicomponent materials such as typically used for Li-ion batteries. Recently, our group established a novel CVD precursor delivery system applying CO2-laser flash evaporation of solid precursors (LA-CVD) and demonstrated its applicability for Li-ion battery research.[3]

In this contribution we report on the latest progress in LLZO thin-film deposition using LA-CVD. The detailed characterization includes results on microstructure, phase composition and electrochemical performance. Thin-films that are dense, free of cracks and mainly consist of tetragonal LLZO show a Li-ion conductivity of about 10-6 S·cm-1, probed with impedance spectroscopy. This compares with lithium phosphorus oxynitride (LiPON), which is a glassy solid electrolyte typically used in current all-solid-state cells. To further improve the Li-ion conductivity of the LLZO thin-films two approaches are followed up: one is to increase the bulk conductivity by stabilization of the cubic LLZO phase via doping. The second is to reduce the grain boundary contribution by tuning the morphology of the thin-films.

References:

[1] R. Murugan, V. Thangadurai, W. Weppner, Angew. Chem. Int. Ed.
2007, 46, 7778-7781.
[2] M. L. Hitchman, K. F. Jensen, Chemical Vapor Deposition: Principles and Applications, Academic Press, London 1993.
[3] C. Loho, A. J. Darbandi, R. Djenadic, O. Clemens, H. Hahn, Chem. Vap.
Deposition
2014, 20, 152-160.
Reversible Na-Ion Uptake in Si Nanoparticles
Authors: Xu Yaolin , Swaans Ellie , Borsa Dana M. , Mulder Fokko M. 
Published: February 2020

Na ion batteries attract significant research interest since they provide potentially high energy density while using low cost and abundant sodium as the active ion. Si has been extensively investigated for its operation as anode in lithium based batteries since it has a high theoretical lithiation capacity up to Li4.4Si. However, the sodium analogue with successful reversible electrochemical sodiation of Si has not been reported yet. Si sodiation is anticipated to be different with respect to phase behaviour, insertion voltages and kinetic barriers when compared to Li ion, for instance because of the difference in ionic radius of Na+ (0.97 Å) and Li+(0.68 Å). From thermal synthesis of Na-Si materials it is known that NaSi is the most Na rich phase for Na-Si binary compounds, which would enable a sizeable capacity of 954 mAh/g.
Anticipating that nanoscaling is of advantage for the kinetics of ion insertion and extraction, we studied Si particles with much reduced size (~ 20 nm) containing a large fraction of amorphous Si. The nano particles were obtained from Expanding Thermal Plasma Chemical Vapour Deposition (ETPCVD) of silane. The materials consist of aggregated individual nano particles with a very thin silicon oxide layer that forms after contact with air. The work presented here reports, to our knowledge for the first time, reversible electrochemical Na ion uptake in these Si based materials for a significant capacity. The desodiation capacity is stable around 260 mAh/g, while the initial sodiation shows a large irreversible Na loss attributed to SEI formation. The experiments show that during Na insertion a two phase equilibrium may be present between NaSi and Si: x Na + Si -> x NaSi + (1-x) Si, where the NaSi becomes amorphous. For desodiation a sloping voltage profile is observed indicative of a solid solution behaviour. Therefore we propose that desodiation occurs as NaSi -> Na1-xSi + x Na, where the Na1-xSi phase remains amorphous. After 100 cycles all Si has been transformed to amorphous phases, and no crystalline nano Si particles remain.
In conclusion, nanoparticles containing both amorphous and crystalline Si, produced by ETPCVD, demonstrate an excellent reversible capacity of 279 mAh/g for Si at 10 mA/g and a capacity retention of 248 mA/g after 100 cycles at 20 mA/g. Significant reversible capacities can be achieved at high dis-/charge rates as well. Nanoscaling benefits the Na insertion and extraction kinetics in Si although reversible Na uptake and release for the full theoretical capacity has not been reached. Initial amorphous and crystalline Si are performing an equally active role in the electrochemical sodiation. Coexistence of Si and NaSi may occur during Na insertion into amorphous Si and on the surface of the Si crystallites; while a solid solution desodiation reaction is evidenced when Na is being extracted.
Y. Xu, E. Swaans, S. Basak, H. W. Zandbergen, D. M. Borsa, F. M. Mulder, Adv. Energy Mater. 2015, doi 10.1002/aenm.201501436 early view

Figure 1
Robust Electron-Donating Organic Compounds for Non-Aqueous Redox Flow Batteries
Authors: Odom Susan A , Kaur Aman Preet , Casselman Matthew D , Elliott Corrine F , Attanayake Harsha A , Parkin S R , Risko Chad 
Published: February 2020

The development of robust electro-active materials is critical for a variety of electrochemical energy storage applications. Phenothiazines, phenoxazines, carbazoles, and triphenylamines are among some of the numerous electron-donating aromatic compounds that have been studied for numerous applications in organic electronics, photovoltaics, and electrochemically-mediated synthesis. Their use as electrolyte components and electrode materials has only been studied by a few groups, yet these materials are easy to functionalize, enabling tuning their electronic properties, solubility, and stability. My research group initially explored derivatives of these compounds as redox shuttles for overcharge protection of lithium-ion batteries. With systematic variations in structure, our efforts combining analytical techniques with density functional theory calculations have enabled us to identify decomposition products and to predict reasonable mechanisms that lead to failure in neutral and oxidized states. Our development of robust derivatives that survived for thousands of hours of overcharge was a result of the design rules that came from these studies. Recently we have expanded our use of these compounds as catholyte components for non-aqueous redox flow batteries. In one to three steps from commercially available materials, we have prepared highly soluble phenothiazine derivatives (solubility of 1-2 M in organic electrolytes) that can serve as one- and/or two-electron donors with long lifetimes in the charged states. This presentation will focus on the synthesis, spectroscopic, and electrochemical analysis of these materials as electron donors for redox flow batteries.
Metallic Lithium Anode Protect By Gel Electrolyte in Lithium-Sulfur Batteries
Authors: Zhong Hai , Xu Zhibin , Sang Lin , Ding Fei 
Published: February 2020

Lithium metal is an ideal battery anode. However, dendrite growth and limited coulombic efﬁciency during cycling have prevented its practical application in rechargeable batteries.[i]Herein, we report a gel electrolyte which have a highly effective to reducing the corrosion and suppressing the formation of lithium dendrites.
Electro-polymerization method was adopted to synthesize the Gel electrolyte, because it doesn’t need any other catalysts for polymerization, and it can be used directly without any further purify. LiTFSI was chosen as the lithium salt for saturation, and DOL monomer as the solvent for electropolymerisation. Figure 1a-c are typical photographs of the electrolyte with different forms which corresponding the prepared steps. It can be seen that the saturation electrolyte (LiTFSI/DOL) kept the characteristics of the liquid with its low viscosity (Figure 1a). After electro-induced polymerisation for several hours, the viscosity of the as-prepared electrolyte increased significantly compared to that of the saturation electrolyte, but it could slowly flow down the bottle wall when inverted (Figure 1b). Further self-polymerisation of the as-prepared electrolyte for more than two weeks at room-temperature produced a transparent solid polymer electrolyte which was immobile upon inversion of its container (Figure 1c).
Figure 2 show the typical scanning electron microscopy images (SEM) of metallic lithium anodes after long cycling experiments in Li-S cells. From these images, both of lithium anode with TEGDME and PIS electrolyte had an obvious change compared with fresh lithium, but the PIS electrolyte shows much the lower damage level of metallic lithium anode compared with the TEGDME.
The morphology of metallic lithium anodes which demonstrates that the gel electrolyte system can effectively inhibit the polysulfide diffusion, thus it can be reducing the corrosion. And also the ultrahigh lithium salt concentration and high viscosity can suppress the formation of lithium dendrites, and decrease the solubility of lithium polysulfide due to the common ion effect.

[i] J. F. Qian, W. A. Henderson,W. Xu, P. Bhattacharya, M. Engelhard, O. Borodin and J. G. Zhang. Nature Communications, 2015, 6, 6362.

Figure 1