bluuebunny/crossref_metadata_2025_split huggingface dataset:
Electroless Plating of Diffusion Barrier Films on SiO2 and Evaluation of Film Characteristics
Authors: Hirate Atsushi , Ohta Kohei , Miyachi Yuto , Shimizu Tomohiro , Ito Takeshi , Shingubara Shoso 
Published: February 2020

For fabrication of through-silicon via (TSV) of 3-D integration, sputtering or ALD are used for the barrier and seed layers formation, however, high cost processes using high vacuum instruments have hindered wide application of 3-D integration technologies. We have studied formation of barrier and seed layers with electroless plating which enables significant reduction of fabrication cost [1, 2]. Use of Pd nanoparticle catalyst adsorbed on silane coupling agent at TSV sidewall [3] is very effective for a highly conformal film deposition in the high aspect ratio TSV holes. In this study, we formed electroless barrier films such as CoWP and NiWP on SiO2 at various bath conditions. We evaluated film characteristics such as electrical resistivity, crystalline structure, adhesion property, alloy composition, Cu diffusion barrier properties, etc.
Figure 1 shows SEM cross-sectional images of the barrier films and XRD profiles before and after annealing (400 oC, 30min. in vacuum).The crystalline structure of the as deposited CoWP film was amorphous and it remained almost amorphous after heat-treatment. On the other hand, the crystal structure of the as deposited NiWP film was also amorphous, but several peaks of NiP alloy appeared after heat-treatment and it turned to poly crystal film.
In addition, we formed Cu seed layer on the barrier metal by displacement plating and studied Cu inter- diffusion properties after annealing.
Reference
[1] F. Inoue, T. Shimizu, H. Miyake, R. Arima,T. Ito, H.Seki,Y. Shinozaki, T. Yamamoto, and S.Shingubara, Microelectronic Engineering, 106(2013) 164–167.
[2] F.Inoue, T.Shimizu, T. Yokoyama, H. Miyake, K. Kondo, T. Saito, T. Hayashi, S. Tanaka, T. Terui and S. Shingubara, Electrochimica Acta, 56-17 ,6245-6250, (2011).
[3]W. J. Dressick, C. D. Dukey, J. H. Georger. Jr, G. S. Carabrese, and J. M. Calvert, J Electrochem. Soc., 141 (1) 210 (1994)

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Structural Stability of Nickel-Rich Layered Cathode Materials
Authors: Tian Chixia , Xu Yahong , Nordlund Dennis , Xin Huolin L. , Liu Yijin , Doeff Marca 
Published: February 2020

To increase the energy density of Li batteries (including conventional Li ion batteries and solid state batteries), cathode materials with higher voltages and/or higher capacities are required, but safety and cycle life should not be compromised. Nickel-rich LiNi1-x-yMnxCoyO2 (NMCs) can provide higher capacities and lower cost in comparison with low nickel content NMCs.1 In order to make nickel-rich NMCs viable for commercial lithium batteries, methods need to be developed to improve the structural stability (i.e., crystal structure, electronic structure)2 upon battery cycling and/or under abused thermal conditions.3 Therefore, a thorough evaluation of the effects of synthesis conditions, chemical composition, and cell history on the structural stability, both at the surface and in the bulk, will lead to better understanding of these materials and eventually enable higher capacity, robust and structurally stable positive electrode materials.
In this study, NMCs with various chemical compositions were synthesized and cycled to different states of charge at various cycle numbers and voltage windows. In situ and ex situ characterizations (XRD, XAS, TXM and STEM-EELS) were performed to study the evolution of crystal and electronic structures at multiple length scales. It was found that in nickel-rich NMCs (e.g., NMC622) the structural change involved all three transition metals, in particular, the participation of nickel is much stronger than low nickel content NMCs. For example, the oxidation state of surface nickel ions is not reversible in a charge-discharge cycle, which is likely related to the surface reconstruction phenomenon (formation of disordered rock-salt structure). Furthermore, the structural change can occur both at the surface and to some degree in the bulk of nickel-rich NMCs, when cycled to higher voltages (>= 4.7 V vs Li+/Li), or under thermal conditions. As the nickel content increases, the structural behavior becomes closer to LiNiO2 materials, with several phase changes. The roles of cobalt and manganese are similar to those in low nickel content NMCs.
(1) Liu, W.; Oh, P.; Liu, X.; Lee, M.-J.; Cho, W.; Chae, S.; Kim, Y.; Cho, J. Angew. Chem. Int. Ed. Engl.
2015, 54, 4440.
(2) Lin, F.; Markus, I. M.; Nordlund, D.; Weng, T.-C.; Asta, M. D.; Xin, H. L.; Doeff, M. M. Nat. Commun.
2014, 5, 3529.
(3) Bak, S.-M.; Hu, E.; Zhou, Y.; Yu, X.; Senanayake, S. D.; Cho, S.-J.; Kim, K.-B.; Chung, K. Y.; Yang, X.-Q.; Nam, K.-W. ACS Appl. Mater. Interfaces
2014, 6, 22594.
Novel Mesoporous Microspheres of Al and Ni Doped LMO Spinels and Their Performance As Cathodes in Secondary Lithium Ion Batteries
Authors: Mukherjee Santanu , Schuppert Nicholas David , Bates Alex , Choi Moon Jong , Kim Sungjin , Son Eunjin , Ryu Wonjae , Park Sam 
Published: February 2020

1. Introduction – Lithium manganese oxides (LMO) based spinels are important cathode materials for Lithium ion batteries (LIBs). However the primary problem of these electrodes are that they suffer structural deformation owing to the Jahn-Teller distortion[1]. This reduces their lifetime and the efficiency of the battery greatly reduces with cycling. However, some improvement have been obtained by adding transition metals and/or modifying the surface area of the electrode materials. This abstract focuses on developing novel porous Ni and Al based LMO microstructures for LIB applications[2].
2. Experimental fabrication – The LMO fabrication is done from their precursors. Initially MnCO3 microspheres are obtained from NaHCO3 and MnSO4.H2O precursors. This reaction is done in the liquid phase and once the two precursors are mixed, immediate formation of a white precipitate is noticed. Once this is obtained, the MnCO3 hollow spherical precursors are then reacted with LiOH by solid state reaction technique in stoichiometric amounts to obtain the LiAl0.1Mn1.9O4 (LAMO) and LiAl0.1Ni0.1Mn1.8O4 (LANMO) microspheres.
3. Results –Charge-discharge analysis have been performed at a constant current density of 0.5 mAcm-2by an Arbin instrument up to 4.5 V and discharged to 2V. The discharge curves follow the characteristic pattern of the LMO spinel based compounds. A phase changes is noticed during the discharge process, at ~ 4.1 V and ~ 2.75 V corresponding to the kink in the discharge. The second phase change at ~ 2.75 V is due to theJahn-Teller effect which produces a permanent deformation of the crystal lattice and steady loss of capacity. The maximum discharge capacity of the LAMO sample is 122.51 mAhg-1 and 75th cycle discharge capacity is 42.22 mAhg-1. The LANMO sample provides a 1st cycle discharge capacity of 140.49 mAhg-1 and a 75th cycle discharge capacity of 66.24 mAhg-1. The LANMO system is seen to be superior in performance as compared to the LAMO system. This is due to the stabilizing role that the added Ni has provided to the crystal lattice, improving the cathodes ability to perform stable intercalation. The performance of these electrodes is demonstrated in Figure 1(a-c).
4. Conclusions – This research provides an insight in to the study of spinels at relatively low voltages which is not so prevalent in the literature. Also a novel technique is used to produce highly porous LMO based spinel spheres which serve to have enhanced electrochemical capacity and cell performance.
References:
[1] B.J. Hwang, R. Santhanam, D.G. Liu, Y.W. Tsai, Journal of Power Sources, 102 (2001) 326-331.
[2] R. Thirunakaran, B.R. Babu, N. Kalaiselvi, P. Periasamy, T.P. Kumar, N.G. Renganathan, M. Raghavan, N. Muniyandi, Bulletin of Material Sciences, 24 (2001) 51-55

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48V Starting Battery Based on 3D Electrode Concept
Authors: Prochazka Jan 
Published: February 2020

Thin film technologies (2D) producing lithium ion accumulators have nearly been optimized. The capacity limits are given by the thickness of the components, especially of the foils and separators.
Although the thin film technology is advanced, it does not meet all technical and safety parameters and use in automobile industry is price prohibited. A significant improvement of safety and production cost of lithium batteries is achievable by changing the production process, i.e. extending of the electrode thickness from micrometers (2D) to millimeters (3D).
The HE3DA®48V battery parameters for new generation of automobile vehicles will be demonstrated including high cycle life exceeding 450 000 cycles (5% capacity deep starts).

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An Efficient and Controllable Prelithiation of Silicon Monoxide for Improving Energy Density of Lithium-Ion Rechargeable Full Cells
Authors: Kim Hye Jin , Choi Sunghun , Lee Seung Jong , Seo Myung Won , Lee Jae Goo , Lee Yong Ju , Kim Eun Kyung , Choi Jang Wook 
Published: February 2020

High capacity silicon (Si) anodes are expected to play a key role in increasing the energy density of current lithium-ion batteries (LIBs). In spite of this attractive feature, its huge volume change over repeated cycles impairs the cycle life through pulverization, film delamination, and unstable solid-electrolyte-interphase (SEI) formation, and thereby hinders its practical applications. As an alternative approach, silicon monoxide (SiOx) phase has been recently adopted because its SiO2 background matrix can buffer the volume expansion of inner Si nano-domains. Nonetheless, most of these phases suffer from inferior performance, namely initial Coulombic efficiency (ICE). This shortcoming originates from Li ion trapping in the matrix and SEI layer formation during the first lithiation. In an attempt to catch the two challenging rabbits (cycle life and ICE), the current study has developed delicately controlled pre-lithiation for SiOx anodes. It should be first noted that a proper degree of lithiation is very critical for stable full-cell operations.
We pre-lithiate the pristine electrode via an electrical short with Li metal foil in the presence of an optimized circuit resistance while simultaneously monitoring the voltage between both electrodes. Utilizing a fine-tuning capability in the degree of lithiation, a pre-lithiation condition that simultaneously maximizes the ICE and cycle life was found and was also engaged for robust full-cell operations by pairing with a commercially available high capacity cathode. The accurate shorting time and voltage monitoring allow a fine tuning on the degree of pre-lithiation without lithium plating, to a level that the initial CE reaches 94.9%. The excellent reversibility enables robust full-cell operations in pairing with an emerging nickel-rich layered cathode, Li[Ni0.8Co0.15Al0.05]O2, leading to a full cell energy density 1.5 times as high as that of graphite-LiCoO2 counterpart in terms of the active material weight. The given procedure is compatible with the existing roll-to-roll manufacturing line and so must be immediately applicable to the current state of the art LIB anodes containing certain contents of SiOx.

Figure 1. Electrochemical characterization of c-SiOx/ Li[Ni0.8Co0.15Al0.05]O2 full cells mad
e of the pristine and 30 min pre-lithiated c-SiOx. (a) Voltage profiles of the first cycles. (b) Cycling performance, with regard to the areal capacity.

Figure 1
Bulk and Interfacial Kinetics of Li1-XNi0.8Co0.15Al0.05O2 (NCA) Single Particles As a Function of State of Charge
Authors: Tsai Ping-chun , Wen Bohua , Yu Hui-Chia , Choe Min-Ju , Thornton Katsuyo , Chiang Yet-Ming 
Published: February 2020

Abstract

At the length scale of electrode particles, interfacial reaction and/or bulk diffusion may determine rate-performance of lithium ion batteries (LIBs). In a conventional cell, in which electrodes are composed of active materials, binders, conductive agents, and current collectors, the mixtures of different materials result in a complex architecture, posing a great challenge to extract the intrinsic kinetic parameters of the electrode materials. In this work, we conduct single-particle experiments to directly measure the particle-level kinetics, and elucidate the rate-performance determining factors in LIBs. The scheme of our single-particle measurements is shown in Figure 1 [1]
Li1-xNi0.8Co0.15Al0.05O2(NCA) is chosen as the model electrode material because of its extensive commercial utilization in LIB cathodes [2]. Here, for the first time, NCA single-particle kinetic parameters, including bulk diffusivity and exchange current density, at different states of charge (SOC) and particle sizes are systematically investigated using electrochemical impedance spectroscopy (EIS) and potentiostatic intermittent titration technique (PITT). Based on these obtained particle-level kinetic parameters, we directly evaluate the relative kinetic contributions to overpotential at the particle level as a function of SOC and particle size, using Biot number analysis [3,4]. In coordination with the experiments, single-particle electrochemical simulations [5,6] that take the particle geometry, interfacial transport, and surface reactions into account are performed with EIS and PITT conditions. Experiments and simulations are together applied to examine and interpret the bulk and interfacial kinetics of NCA single particles.
Keywords: Single-particle measurements; bulk kinetics; interfacial kinetics; rate-limiting step; state of charge; NCA

Acknowledgments

This work was supported as part of the North East Center for Chemical Energy Storage (NECCES), an Energy Frontier Research Center funded by the U.S. Department of Energy, Office of Science, Basic Energy Sciences under Award # DE-SC0012583. P.-C. Tsai thanks the Ministry of Science and Technology, Taiwan (MOST 104-2917-I-006-006), for financial support.

References

[1] I. Uchida et al., J. Power Sources, 68, 139 (1997).
[2] R. Amin et al., J. Electrochem. Soc., 162, A1163 (2015).
[3] J. Li et al., J. Phys. Chem. C, 116, 1472 (2012).
[4] C. Montella et al., J. Electroanal. Chem., 518, 61 (2002).
[5] H.-C. Yu et al., Modelling Simul. Mater. Sci. Eng.
20, 075008 (2012).
[6] H.-C. Yu et al., submitted to Comput Mater Sci

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Hierarchical MoS2-Carbon Microspheres: A Robust Anode for High Performance Lithium Ion Battery
Authors: Chen Gen , Luo Hongmei 
Published: February 2020

With higher theoretical lithium ion capacity of 670 mAh g–1 comparing with commercial graphite electrodes, molybdenum disulfide (MoS2) may be a promising alternative for lithium ion batteries (LIBs) because it offers unique layered crystal structure with Mo atoms sandwiched between two layers of closely packed S atoms and the MoS2 layers are linked by weak van der Waals interaction. The large and tunable distance between layers enables the anticipated excellent rate and cycling stability because they can promote the reversible lithium ion intercalation and de-intercalation without huge volume change and consequently prevents the pulverization of active materials during the repeated charge and discharge processes. However, either bulk or nanoscale MoS2 delivers poor conductivity for the electron/ion transfer, thus leading to obvious capacity loss after several cycles. Moreover, the MoS2 based electrodes provide high capacity through similar electrochemical redox reactions with lithium sulfide batteries in essence, which may also lead to their degradation by the polysulfide shuttling effect.
To overcome these barriers, numerous efforts have been devoted into the engineering of MoS2 nanostructures with optimized electrochemical performances. One effective strategy is to make the MoS2 into a few expanded layers, which provides a larger surface area, shorter lithium ions diffusion path and thus improved kinetics. On the other hand, combining conductive materials such as carbon or polymer with MoS2 will necessarily enhance the electron transport, cycling stability, structural integrity during the lithium-ion insertion/extraction processes. Herein, we prepared hierarchical MoS2-carbon microspheres via continuous and scalable ultrasonic nebulization route. The structure, composition, electrochemical properties are investigated in detail. The MoS2-carbon microspheres consist of MoS2 nanosheets with a few layers bridged by carbon (15 wt%), which separates the exfoliated MoS2 layers and prevents their aggregation and restacking. The novel architecture offers additional merits such as overall large size, high packing density, which promote their practical applications. The MoS2-C microspheres have been demonstrated to deliver excellent electrochemical performances in terms of low resistance, high capacity even at large current density, stable cycling performances, etc. The electrodes exhibited 800 mAh g–1 at 1000 mA g–1 over 170 cycles. At higher current density of 3200 mA g–1, a capacity of 730 mAh g–1 can be also maintained. The MoS2-C microspheres are practically applicable not only because of the continuous and large scale synthesis via current strategy, but also the robust and integrated architecture which ensures the excellent electrochemical properties.
Influence of Decreasing Electrode Thickness on Its Structure and Resistance for Lithium-Ion Batteries
Authors: Araki Chieko , Tsubouchi Shigetaka , Noie Akihiko , Nishimura Etsuko , Suzuki Shuichi , Makino Shigeki 
Published: February 2020

Introduction

An internal resistance in an electrode for lithium ion batteries (LIB) is consisted of three resistances, which are an electric resistance, ionic resistance and charge-transfer resistance. Since a length of Li-ion conductive pathways decreases with decreasing electrode thickness, the internal resistance can be reduced by decreasing the electrode thickness [1]. Therefore, decreasing the electrode thickness is one of the effective methods to improve the power of LIB. On the other hand, making the thin electrodes by the same procedure as the thick electrodes probably causes a change in the electrode structure and increase of the internal resistance. However, it has not been clarified.
In this study, the LIB electrodes with various thicknesses were examined to clarify the influence of decreasing the electrode thickness on its structure and the internal resistance. Half cell tests and scanning electron microscopy with focused ion beam (FIB-SEM) analyses were carried out to evaluate electrochemical and structural properties of the electrodes.

Results and Discussion

Fig. 1 shows the electrode thickness dependence on the three resistances: the ionic resistance (Rion), charge-transfer resistance (Rct), and total internal resistance (R).The resistances are normalized by the weight of active materials. At around 15 μm of the electrode thickness, R showed the minimum. At less than 15 μm of the electrode thickness, R increased due to the Rct increase. Fig. 2 shows 3D reconstructed images of active material phase, acetylene black (AB) and binder phase, and pore phase in the thin (9 μm) and thick (25 μm) electrodes . The porosity of the thin electrode was larger than that of the thick electrode. In addition, the ABs and binder in the thin electrode were dispersed less uniformly than those in the thick electrode. The large porosity and localization of the ABs and binder could produce a high contact resistance among active materials. As a result, the reduced reactive surface area increased the Rct in the electrode.
In our presentation, we will discuss the influence of decreasing the electrode thickness on .the Rct more detail with other analysis results, and the method for improving Rct.

Acknowledgment

This work was supported by New Energy and Industrial Technology Development Organization (NEDO) of Japan.

Reference

[1] C. Fongy et al. , J. Electrochem. Soc ,
157, A885 (2010).

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First Principle Investigation of C606 Molecule Absorption on Graphene As 2D Eco-Electrode of Lithium-Ion Battery
Authors: Wang Zicheng , Meng Junxia , Xu Lishuang , Xu Huaizhe 
Published: February 2020

Abstract: The use of organic electrodes draws more attentions recently as its synthesis and disposal are both environment-friendly. The oxocarbon salt Li2C6O6 and tetralithium salt Li4C6O6 bulk organic materials have been prove to be efficient by Chen et al. Even these renewable materials exhibit good cycling and rate abilities and have specific capacity of upmost 580 mAhg-1. However, the drawback such as low output voltage and soluble organic molecules are also obvious. On the other hand, graphene is known as a 2D crystal structure with atomic thickness and marvelous electronic structure and high mechanical strength. Hence we here propose a novel combination of graphene and C6O6 molecules. The coverage rate is set to every single C6O6 molecule @6*6 graphene supercell to avoid the possible interaction of neighbor molecules. Three kinds of high symmetrical positions are developed and labeled as AA, AB and AB-r. In our DFT calculation containing vdW force effect, Li atoms are set at Top(T), Hollow(H) and Bridge(B) site of these structures separately. And by viewing the evolution of Li atoms and comparing the final energies of nearly 70 types of positions, we note that Li atom is favorable to function with carbonyl group in all three structures. Moreover, graphene works as a stabilizer in this system, which is believed to increase the cycling capability of this electrode. We also demonstrate that the electron of Li atom prefers to transfer to C6O6 molecule instead of graphene from partial charge density calculations.
Keyword: Li-ion battery, DFT, C6O6, graphene.

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