bluuebunny/crossref_metadata_2025_split huggingface dataset:
Prediction of Volumetric, Specific Energy and Power Density of High-Capacity Thin Layer Battery Electrodes By Using a Novel Multi-Scale Modelling Framework
Authors: Kriston Akos , Pfrang Andreas , Popov Branko N 
Published: February 2020

In this work, a novel modelling approach is presented, which is able to directly relate the microstructure of the active layer of thin-film batteries to the battery cell macroscopic behaviour. A general pore-scale model has been developed by mimicking the layer fabrication process. Five different electrode structures were reconstructed taking into account the interaction between the deposited particles during the layer formation. In each simulation 108particles were deposited with 5 different sticking rules. Fig.1. captures the beginning of the layer formation. Fig.1a) shows weak interaction between the particles, i.e. the layer is mainly governed by random deposition, and b) strong attractive forces, i.e. every particle sticks to the nearest neighbour. The different colours correspond to the deposition of 1000 particles, while white spaces correspond to open pores.
Instead of simulating each type of reconstructed layer, the renormalization group theory is applied to analyse the effect of thickness on the properties of the active layer. It is shown, that in spite of the very different morphology, all these reconstructed layers belong to the same universality class and can be described by a general non-linear scaling law. The simulation results imply that porosity and specific surface area depend on the thickness of the electrode, which is not commonly considered in battery models. The general expression derived is incorporated into a macrohomogeneous model and the charge-discharge performance is simulated. The volumetric and specific energy and power densities are calculated and finally, the simulation results are compared with measured data at different thicknesses.
The developed method offers an efficient tool not only to predict, but to design high power and high capacity batteries for automotive applications and/or scale down dimensions for microelectronics and MEMS. It can be used for fast screening of novel manufacturing technologies as well as for deeper understanding of the effect of microscale structure on the macroscopic behaviour of battery cells.
In Situ Electron Microscope Observations of Electrochemical Lithium Deposition/Dissolution with a Glassy Solid Electrolyte
Authors: Ejiri Makoto , Motoyama Munekazu , Iriyama Yasutoshi 
Published: February 2020

Introduction

The recent discoveries of inorganic solid electrolytes with large Li+ ionic conductivities have greatly propelled the research on all-solid-state lithium batteries. Solid electrolyte blocks Li dendrite growth toward the cathode if Li metal is used as the negative electrode. This is certainly attractive because the theoretical energy density of Li metal (2062 Ah L-1) is much greater than those of presently commercialized negative electrodes (e.g. graphite). It is hence important to understand how Li metal grows and dissolves through solid electrolyte interfaces in the charge-discharge processes [1]. This study reports in-situscanning electron microscope (SEM) observations of the initial stage of Li growth at electrode/amorphous solid electolyte interfaces.

Experimental

The mojority of the electrolyte (1.25 cm × 1.25 cm) is a mirror-polished Li1.3Al0.3Ti1.7(PO4)3 (LATP) sheet (OHARA Co.) with a thickness of 150 μm. Its top and bottom surfaces were sputter-coated with lithium phosphorus oxynitride (LiPON) layers with thicknesses of 2.5 μm. The working electrode is a 30-nm-thick-Cu film onto a circular area with a diameter of 5.0 mm in the center of the top LiPON surface. The counter electrode is a 3-4-μm-thick-Li film on the bottom LiPON surface. Electrochemical Li deposition and dissolution were conducted in a Keyence VE-9800 SEM under galvanostatic conditions. Li deposition/dissolution are carried out at 50 μA cm-2 to 3 mA cm-2. The total charges are 180 mC cm-2 for all curent densities. This charge amount corresponds to a plating of a 242-nm-thick Li film if the plated film formed a contiguous solid thin film.

Results and discussion

Figure 1 shows SEM images of the growth trajectories of different Li nuclei at 100 μA cm-2. Li nuclei under a Cu film eventually break the Cu film to grow Li rods. Li deposits break a Cu film at approximately 240 s. Once a Cu film is cracked, new Li nucleation no longer occurs. Thus, strain energies in Li and Cu are considered to influence the Li nucleation and growth under a Cu film. At 1.0 mA cm-2, the number of Li nucleation sites increases. Additionally, rapid agglomeration of Li nuclei under a Cu film is observed (Figure 2). In contrast to the case at 100 μA cm-2, Li rods do not grow through cracks of a Cu film.
Li dissolution reactions were also observed by in-situ SEM, and Li self-diffusion in Li rods seems to dominate the stripped length within a rod. Morphological changes of a Cu film at the first cycle influence the preferential sites for Li growth at subsequent cycles. Li deposition/dissolution reactions will be further discussed in more detail with in-situ SEM movies.

Reference

[1] F. Sagane, K. Ikeda, K. Okita, H. Sano, H. Sakaebe, and Y. Iriyama, J. Power Sources, 233 (2013) 34.
Lithium Distribution in Monocrystalline Silicon-Based Lithium-Ion Batteries
Authors: Janski Rafael , Fugger Michael , Sternad Michael , Wilkening Martin 
Published: February 2020

There is a growing demand on power sources for micro-system applications. Li-ion micro batteries (µ-batteries) with silicon-based anodes may fulfill the necessary requirements. Silicon shows superior properties as anode material in batteries such as a very high specific capacity [1]. Well-engineered manufacturing techniques allow a high level of integration into silicon-based semiconductor devices [2].
One challenging topic for the integration concerns lithium distribution inside the anode to understand the cyclability of silicon. Moreover, the prevention of loss of Li-ion in non-active areas of the battery is a key issue. Therefore, the introduction of a tight barrier layer is essential for such systems [3]. For these investigations analytical techniques are required, which can obtain information on the lateral as well as depth lithium distribution.
Surface structured silicon and sputtered diffusion barriers on silicon were tested as working electrodes in a half-cell Swagelok® design together with a EC: EMC, LiPF6-based electrolyte. Two mass spectrometry based techniques were applied to investigate the properties of structured silicon anodes together with the barrier characteristics of refectory metal materials: (i) ToF-SIMS was used as imaging technique for depth profiling the first micrometers and (ii) Laser ablation ICP-MS allowed to measure depth-profiles of up to hundreds of microns perfectly complementing the ToF-SIMS technique.
The presented study focuses on the non-uniform Li-distribution in silicon anodes with the aim to avoid structural weak hotspots due to locally unbalanced dilatation. Beside the detailed investigation of the native anode structures we tested different silicon-barrier combinations, e.g., Si – TiN, to clarify their potential as Li-inert material in future battery applications (see Fig. 1).

Acknowledgement

Financial support by the Federal Ministry of Economy, Family and Youth and the National Foundation for Research, Technology and Development is gratefully acknowledged. Moreover, we thank Infineon Technology Austria AG for financial and technical support.

References

[1] B.A. Boukamp, G.C. Lesh, R.A. Huggins, All-solid lithium electrodes with mixed-conductor matrix. J. Electrochem. Society, 1981, 128, 4, 725-729
[2] J.F.M Oudenhoven, L. Baggetto, P.H.L Notten, All-solid state lithium-ion microbatteries: A review of various 3D concepts. Adv. Energy Mater., 2011,1, 10-33
[3] J.E. Trevey, J. Wang, C.M. Deluca, K.K. Maute, M.L. Dunn, S-H Lee, V.M. Bright, Nanostructured electrodes for solid-state 3D rechargeable lithium batteries, Sensors and Actors A167, 2011, 139-145
Figure 1: ToF-SIMS profile of a sputtered titanium nitride barrier layer on a highly doped Si substrate after 10 cycles vs. a lithium counter electrode in EC:EMC (3:7), 1 M LiPF6.
Interaction Mechanism Between SEI Lithium Salts and Glymes or Surfactant as Additive in Li-Ion Batteries
Authors: Chretien Fabien , Jones Jennifer , Damas Christine , Lemordant Daniel , Galiano Hervé , Willmann Patrick , Anouti Mérièm 
Published: February 2020

Lithium-ion batteries (LIB) are undoubtedly the most popular and mature electrochemical storage devices and, for future use, a higher degree of safety, a longer cycle life, and a higher specific energy are desirable. In order to achieve this goal, numerous publications have been devoted to new active materials and new electrolytes [1] but far less to interfaces. As a matter of fact the solid-electrolyte interphase (SEI) formed through the reductive decomposition of solvent molecules plays a crucial role in the performances of LIB. The robustness and efficiency of the SEI [2] therefore significantly affect the power capability, stability, safety and cycle life of a LIB.
In this study, we investigate the impact of several lithium salts, already present in the SEI like LiF, Li2O, LiOH, Li2CO3, LiOCH3 and LiOC2H5, on the cycling ability of a graphite or LiNiMnCoO2 electrodes [3] in Li half cells containing the standard (EC/PC/3DMC + 1 M LiPF6) electrolyte. These lithium salts are soluble (LiF), slightly soluble (LiOCH3 and LiOC2H5) or almost insoluble (Li2O, LiOH, Li2CO3) but present in solution as a colloidal suspension at saturation. Results show that these lithium salts, dissolved or in suspension in the electrolyte have a non-negligible impact on the electrode capacity during cycling, depending on the type of electrode and nature of the salt. Mineral salts like LiOH, Li2O and LiF (at high concentration) degrade battery performances by forming a resistive film at the electrode surface. On the contrary, LiOCH3 and Li2CO3 are beneficial to cycling performances owing to the formation of a Li conductive coating. In order to avoid the negative impact of dissolved LiF, glymes like diglyme (G2), triglyme (G3) and tetraglyme (G4) have been added as these compounds are known to complex strongly Li+ ions. A complementary approach has been the use of fluorinated surfactant additives able to modify the interfacial material/electrolyte free energy. Electrochemical characterization by galvanostatic cycling and cyclic voltammetry, combined with XPS and SEM surface characterization have been performed to evaluate the impact of each additive and to clarify its mechanism of action. Results show that the addition of glymes limits the negative effect of SEI lithium salts, while the surfactant improves the wettability of the electrodes leading to better cycling performances.
[1] J.B. Goodenough, Y. Kim, Chemistry of Materials, 22 (2010) 587-603.
[2] P. Verma, P. Maire, P. Novák, Electrochimica Acta, 55 (2010) 6332-6341.
[3] Fabien Chrétien, Jennifer Jones, Christine Damas, Daniel Lemordant, Patrick Willmann, M. Anouti, Journal of Power Sources, 248 (2014) 969-977.
Chinese Shadowboxing-Inspired Rigid-Flexible Cellulose-Based Solid Polymer Electrolyte for High Performance Lithium Battery
Authors: Cui Guanglei , Zhang Jianjun , Liu Zhihong 
Published: February 2020

Classical lithium ion batteries based on liquid electrolyte have been developed rapidly. They have brought us
much economic benefit, but it also exited massive potential safety risk. All-solid-state polymer electrolyte
would be a perfect way to solve this problem effectively. Solid polymer electrolyte especially poly (ethylene
oxide) (PEO) running above 80 oC often results in poor mechanical strength and narrower electrochemical
stability window. It is a compelling challenge to exploit solid polymer electrolyte for lithium battery with both
high ionic conductivity and superior mechanical performance. Herein, we reported a new class of Chinese
shadowboxing-inspired rigid-flexible polymer electrolyte based on soft segment PEO and robust cellulose
supporting matrix. Such solid polymer electrolyte solves most of abovementioned disadvantages, with
superior mechanical strength, high ionic conductivity of all-solid-state polymer electrolyte
(1.3×10-4 S cm-1), improved thermal resistance (up to 180 oC) compared with PEO polymer electrolyte.
We believe this would offer a kind of new concept for designing and exploiting rigid-flexible solid
polymer electrolyte by selecting and adjusting various components according to different requirements for
rechargeable metallic lithium batteries (for example lithium-sulfur batteries and lithium-air batteries)
that will overcome the bottlenecks in developing future polymer lithium battery technology that powers
consumer electronics and hybrid electric vehicles.
Nasicon-Type Li-on Conductor for All-Solid-State Li-Ion Batteries
Authors: Lu Li , Zhu Yaqi , Zhang Yunfeng 
Published: February 2020

All-solid-state lithium batteries are regarded as the next-generation power sources because of its superior safety and long cycle lives. But its development is prevented by the lack of solid electrolyte materials with high conductivity and high electrochemical stability. [1]
In past decades, a new family of lithium-ion conductors with Nasicon-type structure has attracted lots of interests due to its high bulk conductivity. However, several drawbacks prevent them from practical application such as low grain boundary conductivity and low electrochemical stability. [2]
To solve these problems, the present study is focused on optmizing the preparation process of an electrolyte material based on NASICON-type structure. A melting quench method has been adopted to eliminate the grain boundary resistance of Nasicon-type electrolyte Li1.5Al0.5Ge1.5P3O12 (LAGP) and the amorphous sheets are heat treated at different temperatures to investigate the relationship between microstructure and ionic conductivity. The highest total conductivity of 2.907x10-3S/cm at 27℃ has been achieved by crystallizing the glass at 800℃ for 8h and its activation energy is measured to be 0.27eV. Systematic characterizations on crystal structure and grain size are conducted to lead to further understandings on mechanism of lithium-ion transportation and grain growth kinetic.
References
[1] Thokchom, J.S., N. Gupta, and B. Kumar, Superionic Conductivity in a Lithium Aluminum Germanium Phosphate Glass-Ceramic. Journal of the Electrochemical Society, 2008. 155(12): p. A915-A920.
[2] Zhang, M., et al., Preparation and Electrochemical Properties of Li1+xAlxGe2-x(PO4)(3) Synthesized by a Sol-Gel Method. Journal of the Electrochemical Society, 2012. 159(7): p. A1114-A1119.
Mechanically Clamped Liquid-PEO Based Block Copolymer Electrolytes for Solid-State Lithium-Ion Batteries
Authors: Rolland Julien , Brassinne Jérémy , Bourgeois Jean-Pierre , Vlad Alexandru , Gohy Jean Francois 
Published: February 2020

During the past two decades, many efforts were devoted to increase the performance of Li-ion batteries[1]. Currently, Li-ion technology using carbonate based liquid electrolyte exhibits the best performances but it’s also famous for safety reason: leakages of corrosive products, explosion hazard and narrow stability window. Solid-state electrolytes are the perfect solution to develop safer lithium devices[2]. By combining lightweight, easy implementation, flexibility and mechanical strength, solid polymer electrolyte appears to be the most attractive alternative. Among various polymers developed, only polyethylene oxide (PEO) is known to solvate a substantial amount of lithium salt. However, relevant ionic conductivities are obtained mainly above the melting point (>65°C), which render this material unpractical for most of applications[3].
Herein, we disclose the design of a mechanically clamped liquid PEO based electrolyte integrating both, high ionic conductivity and mechanical strength at room temperature[4]. Through macromolecular engineering, a bi-functionnal block copolymer is designed combining an anchoring polystyrene (PS) block attached to a polymethacrylate oligoethylene glycol (POEGMA) ionic conductive block. By tuning the relative size of the two blocks, the mechanical properties were finely adjusted to offer excellent mechanical strength. Only minority PS block was necessary to generate glassy PS-nanodomains that provide a robust mechanical anchor to the electrolyte confirmed by rheological measurements (Fig. 1a). The ionic conductivities appear to be barely affected by the PS block, with conductivities approaching 10-5 S/cm, similar to pure POEGMA system at room temperature. To meet the highest performances for mechanically clamped electrolyte, the size of the oligomeric side chain was finely tuned to offer the conductivities above 10-5S/cm.
Furthermore, the bi-functional electrolyte was found to exhibit a wide electrochemical stability window, above 5 V vs. Li/Li+, which renders this material applicable to high voltage cathode batteries. The bi-functional electrolyte also displays a more stable behavior at anodic potentials allowing the formation of a stable electrode interphase after only few cycles (Fig. 1b). Finally, a prototype LiFePO4/PS-b-POEGMA/Li battery is realized demonstrating the applicability of the mechanically clamped liquid PEO based electrolyte for all-solid-state Li-ion batteries.

References

[1] Armand, M., Tarascon, J. M. Building better batteries Nature
451, 652–657 (2008).
[2] Murata, K., Izuchi, S., Yoshihisa, Y. An overview of the research and development of solid polymer electrolyte batteries. Electrochim. Acta 45, 1501-1508 (2000).
[3] Bouchet, R., et al. Single-ion BAB triblock copolymers as highly efficient electrolytes for lithium-metal batteries Nature Materials
12, 452-457 (2013).
[4] Rolland, J., et al. submitted.
New Insights into SEI Formation in Lithium Ion Batteries: Inhomogeneous Distribution of Irreversible Charge Losses Across Graphite Electrodes
Authors: Klink Stefan , Weide Philipp , Muhler Martin , Schuhmann Wolfgang , La Mantia Fabio 
Published: February 2020

The development of lithium ion batteries with long cycle life requires a good control of degradation mechanisms and irreversible charge losses (ICL). The most prominent example in this respect is the use of electrolyte additives such as vinylene carbonate (VC) to improve the physical properties of the Solid Electrolyte Interphase (SEI) [1].
Until now, the SEI was considered to be formed homogeneously throughout the thickness of the electrode. Unfortunately, standard analytical techniques are either surface sensitive or they probe the entire averaged properties of the electrode and hence cannot proof otherwise. Porous electrodes, however, are characterized by a distribution of charge-transfer currents across the electrode due to a mass-transport limitation of educts diffusing from outside the electrode [2]. A multi-layered working electrode (MWE) was therefore developed to resolve electrochemical reactions in this vertical dimension. It was observed that the intercalation of lithium ions into graphite proceeds stage-by-stage and layer-by-layer from top to bottom [3].
For the reduction of electrolyte constituents in small quantities such as additives or contaminants, however, the case is different. The surface layer of the MWE suffers from a higher irreversible reduction current due to an additional influx of reactants from the separator. Since these reactants are fully depleted from the electrolyte during first charge, graphite particles close to the electrode surface effectively act as “electrochemical sieve” for contaminants and additives. X-ray photoelectron spectroscopy (XPS) studies confirm that this sieving effect results in a different SEI on the electrode surface as compared to the electrode bulk. The results presented here are to the best of our knowledge the first direct experimental proof that ICL and SEI are not evenly distributed across graphite electrodes.
[1] P. Verma, P. Maire, P. Novák; Electrochim. Acta
2010, 55, 6332–6341.
[2] J. Euler and W. Nonnenmacher; Electrochim. Acta, 1960, 2, 268.
[3] S. Klink, W. Schuhmann, F. La Mantia; ChemSusChem, 2014, submitted
Material Development of the Lgps Based Solid Electrolytes — Structure, Conductivity and Battery Characteristics
Authors: Kanno Ryoji , Kato Yuki , Ohmin Kwon , Suzuki Kota , Hirayama Masaaki , Yonemura Masao 
Published: February 2020

Lithium superionic conductors, which can be used as solid electrolytes, promise the potential to replace organic liquid electrolytes and thereby improve the safety of next-generation high-energy batteries. Although the advantages of non-flammable solid electrolytes are widely acknowledged, their low ionic conductivities and low chemical and electrochemical stabilities prevent them from being used in practical applications. The new lithium superionic conductor, Li10GeP2S12 (LGPS) exhibits an extremely high bulk conductivity of over 10-2 S cm-1 at room temperature (27 °C), and is a potential electrolyte candidate for an all solid-state battery [1]. In order to explore the material variety of the LGPS based electrolytes, solid solutions of the pseudo binary Li4GeS4 – Li3PS4 system were investigated. In addition, the new material systems were synthesized with the cation and/or anion substitutions (Si, Ge, Sn, O etc). The solid solution was synthesized for the LGPS parent phase in the binary system, and the conductivity varied with the lithium composition. The structures were determined by X-ray and neutron diffraction analyses, and the relationship between the ionic conduction and structures was clarified. The ionic conductivity and electrochemical stability varied with the compositions examined by the cation and/or anion substitutions. Battery performances using these LGPS systems were investigated. Based on the materials varieties and the battery performances using the LGPS electrolytes, the advantages of the all solid-state batteries will be discussed.
Reference
[1] N. Kamaya et al., Nat Mater, 10, 682-686 (2011).