bluuebunny/crossref_metadata_2025 huggingface dataset:
Using a Peg with a Small Molecule Weight to Enhance Copper Bottom-up Filling Performance of through Silicon Via with a Deep and Wide Dimensions
Authors: Chen Po Ting , Dow Wei-Ping , Yang Ping-Feng
Published: February 2020

Three-dimensional (3D) chip stacking has been proposed for a long time, because “More than Moore” concept has been a possible solution to overcome the limitation of gate line width of a MOS. A deep and wide TSV could be superfilled with copper electroplating within 3 houses, by adding polyethylene glycol (PEG) with a small molecular weight, mainly due to its wetting capability. The dimensions of the TSV used in this work were 50 μm diameter and 245 μm depth.

The TSVs used in this work had two types of seed layer. One was a traditional copper seed layer and the other was reduced graphene oxide (rGO) layer. Both TSVs were plated in a copper plating bath containing chloride and acidic copper sulfate as well as a suppressor, leveler and an accelerator. In addition, we added PEG with a small molecular weight. The filled TSVs were examined by cross-sectional analysis using an optical microscope (OM) and a scanning electron microscope (SEM).

Keywords

Through Silicon Via, Copper Electroplating, Reduced Graphene Oxide, 3D IC

References

[1] Wei-Ping Dow, Chih-Chan Li, Meng-Wen Lin, Ging-Wen Su, and Chen-Chia Huang “Copper Fill of Microvia Using a Thiol-Modified Cu Seed Layer and Various Levelers” Journal of The Electrochemical Society. 156(8) D314-D320 (2009).

[2] Kondo, K, Akolkar, R.N, Barkey, D.P, Yokoi, M "Copper Electrodeposition for Nanofabrication of Electronics Devices, Chapter 2 Supression Effect and Additive Chemistry" Springer, Chemistry, Electrochemistry, Nanostructure Science and Technology (2014).

Figure 1
(Invited) All-Wet TSV Fabrication Using Electroless Plated Barrier and Cu Seed Layers with Pd Nanoparticle Catalyst
Authors: Inoue Fumihiro , Shingubara Shoso
Published: February 2020

Fabrication of TSV is one of key technologies for 3D-ICs. Filling of Cu electrode materials in a small dimension of TSV is essential for realizing fine-pitch TSVs, which reduce the lisk of thermal stress concentration issues. Cost reduction is also required to be feasible TSVs for a variety of devices. All-wet fabrication of TSVs using electroless plating of barrier and seed is one of solutions to fullfill these requirements. For realizing conformal thin barrier metal layers of Co-alloy or Ni-alloy electroless barriers in a high aspect TSV, Pd nanoparticles as catalyst are very effective because their adsorption is uniform throughout top to bottom of TSV. Furthermore they shows improvements of adhesion between dielectric and metal [1,2]. Adhesion issue is a serious obstacle for electroless plated films in general, however, we found displacement plating of Cu on electroless plated barrier layer has an excellent adhesion property. Finally, we succeeded in formation of a high aspect ratio TSV with superfilled Cu on electroless barrier/seed layers. Reliability aspects relating interdiffusion of Cu against the barrier layers will be discussed further. 

[1] F.Inoue, T.Shimizu, T. Yokoyama, H. Miyake, T.Ito, H. Seki, Y.Shinozaki, T.Yamamoto,and S.Shingubara, Electrochimica Acta, 82, 372-377 (2012).

[2] F. Inoue, T. Shimizu, H. Miyake, R. Arima, T. Ito, H. Seki, Y. Shinozaki, T. Yamamoto,S.shingubara, Microelectronic Engineering, 106, 164-167 (2013).
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)

Figure 1
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

Figure 1
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).

Figure 1
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

Figure 1
The ANODE Performance of Highly-FINE Silicon Metal Particles Hybridized with PITCH-Derived Carbon in a Li ION Battery
Authors: Fujimoto Hiroyuki
Published: February 2020

Since the first commercialization of Li ion battery, the combination of LiCoO2 cathode and graphite anode has been the major system, and the energy density has been enhanced up to more than twice as the initial value by the various improvements. The capacity of graphite anode attains almost the theoretical value of 372 Ah/kg. Hence, the further enhancement requires the material change from the graphite to the other materials with higher capacity. For such a reason, the Si/carbon composite anode has recently investigated. However, it has not been used for commercialization because of the limited cycling due to the particle size reduction during the charge/discharge reaction. In the present study, the Si was hybridized with pitch-derived carbon in order to improve the cycle degradation, and its anode performances were investigated.
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).

Figure 1
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.

Figure 1
Quinone Derivatives for Lithium-Ion Batteries: First-Principles Density Functional Theory Modeling
Authors: Jang Seung Soon , Lee Seung Woo
Published: February 2020

The Li binding thermodynamics and redox potentials of seven quinone derivatives were investigated as positive electrode candidates for lithium-ion batteries using density functional theory (DFT) method. From our results, it was found that i) Li ions are dominantly bound with carbonyl groups of the molecules, and ii) the redox chemistry of the quinone derivatives can be tuned by the modification of their chemical structures. In this study, the redox potentials of the Li-bound quinone derivatives were also characterized, which provides an insight on the change in the redox chemistry during the discharging processes. The redox potential and charge capacity are improved by modifying the quinone derivatives with electron-withdrawing carboxylic groups. Through this study, it is also found that the cathodic activity of a quinone derivative during the discharging processes strongly relies on the solvation free energy effect as well as the number of available carbonyl groups for further Li binding. To the best of our knowledge, the changes in the redox potential of the redox-active molecules during the discharging processes is reported for the first time.
Investigation of the High-Rate Recharging Mechanism in LiMn2O4 By Primary Particle Analysis
Authors: Ishikawa Satoshi , Ito Tomohiro , Tachibana Kazuhiro , Nishina Tatsuo
Published: February 2020

Introduction

There were two types of lithium manganese oxide (LiMn2O4) supplied by different supplier. They showed similar crystal structure according to the XRD analysis, but the Li+ charging/discharging rate was quite different. To elucidate the working mechanism of this performance difference, we applied the SEM, AC impedance, and ESR measurement on LiMn2O4particles. 

Results and discussion of the experimental

Two kinds of the lithium manganese oxides were used as the active material. The active material as the electrode, was implanted in the gold wire without any binder and conductive additive (99.99%). 1M LiPF6 / EC + DEC (1: 1 volume ratio) was used as the electrolyte, silver is used as a quasi-reference electrode, it was used platinum as a counter electrode.

In this experiment was measured the Cyclic voltammogram of the high-rate lithium manganese oxide (HR-LMO) and non-high-rate lithium manganese oxide NHR-LMO at the potential sweep rate v of 200 mV/s. The HR-LMO was continuously observed the two peaks. However, the NHR-LMO was not observed.

The SEM samples of the cross-section of the active material was prepared using an FIB system. The cross-sectional SEM photograph, was performed at an accelerating voltage of 5 kV using the LV-SEM.In this experiment the average particle diameter of primary particles is 30 nm in the HR-LMO, NHR-LMO were hundreds of nanometers at 10 times or more. This finding indicated that the rate performance of the active material was affected by the primary particles size.

The active material was placed into the impedance measurement jig (S = 1260 mm2, d = 0.9 ± 0.3 mm). The impedance |Z| and phase angle θwere measured by using the LCR meter (NF Corp., ZM-2355).The impedance |Z| of the HR-LMO and the NHR-LMO were 5 kΩ and 200 kΩ, respectively. The phase angle θwere -30 ° and -65 °, respectively. This finding indicated that the active material of the high rate performance was low impedance.5 mg of active material were placed into the cylindrical glass sample tube (inner diameter of 1 mm) as the ESR measurement tube, and the mass of the active material was measured. The ESR measurement tube was placed at the center in the ESR resonator. The ESR spectrum was observed by using the ESR spectrometer (JEOL, JES-RE3X).

The ESR signal of g=2.0 and ΔH=22.2 mT were observed in the HR-LMO. However, the ESR signal was not observed in the NHR-LMO. The ESR signal of g=2.0 may be due to electrons in conduction band, because this value is approximated to g=2.0023 of free electrons.
3D Hierarchical Anode Configuration Composed of Ultralong N-Doped Graphene Scrolls-Wrapped MnO Nanowires for High-Performance Li-Ion Batteries
Authors: Wu Hao , Chen Penghui , Zhang Yun
Published: February 2020

Transition metal oxides (TMOs) have been touted as one of the most promising anode materials for next generation lithium ion batteries (LIBs). Yet, how to build energetic TMOs-based electrode architectures by addressing the structural and interfacial stability issues facing TMOs anodes still remains a big challenge. Here, we design and fabricate a novel 3D hierarchical anode configuration composed of ultralong porous MnO nanowires (NWs) wrapped within nitrogen-doped graphene scrolls (GSC) which themselves interlinked and embedded in continuous interconnected networks of nitrogen-doped graphene ribbons (GR). Such a hybrid material (namely, MnO@N-GSC/GR) with plenty of internal void space is totally in an ordered 3D hierarchical porous architecture by taking the advantage of multi-scale and multi-dimensional integration of nanoscaled MnO and graphene building blocks, which can address all the issues related to MnO dissolution, conversion, aggregation and volumetric expansion during the Li+ insertion/extraction. As a result, the 3D hierarchical MnO@N-GSC/GR serves high-performance anode materials for LIBs with a very high reversible specific capacity (as high as 765 mAh g-1 at even 1000 mA g-1) and ultrafast rate capability (349 and 201 mAh g-1 at 8000 and 15000 mA g-1, respectively), as well as excellent discharge and charge capabilities (rapidly charged to 86.7% and 79.9% in 10.5 and 4.6 min, respectively, using the constant current mode). Most importantly, such the robust MnO@N-GSC/GR electrode shows no capacity fading even after 1000 cycles at a high current density of 2000 mA g-1, and no morphology change. The as-built 3D hierarchical MnO@N-GSC/GR is the most efficient MnO-based anode materials ever reported for LIBs.
Preparation of Pre-Lithiated Sulfur Cathode By an in Situ Contacting Reaction
Authors: Wu Yunwen , Yokoshima Tokihiko , Nara Hiroki , Momma Toshiyuki , Osaka Tetsuya
Published: February 2020

There is an increasing demand for the development of a new kind of secondary battery with high capacity and long cycle life. The sulfur cathode with the theoretical capacity of 1672 mAh/g (sulfur) has attracted researchers' attention.1 However, the Li-S batteries faces huge challenges because of the capacity fading caused by the polysulfide's shuttle effect and the safety issues caused by the lithium metal. Recently, researchers were attracted on the fabrication of metallic lithium free battery with the lithiated sulfur cathode.2 However, due to the high sensitivity of lithium sulfide (Li2S) to the moisture of air, this method have to be taken completely in an inert atmosphere, which raises the manufacturing cost and obstruct the access to commercialization. Consequently, it is urgent to introduce a new way to fabricate the lithiated sulphur cathode to meet the application requirement.

Herein, we prepared Li2S/KB cathode by an in situ synthesis method under the protection of ion-selective polypyrrole (PPy) layer. The anion doped PPy layer was deposited by electrodeposition method on S/KB cathode.3 The layer by layer structure of the cathode was proved by SEM analysis of the cross-section image (showed in Figure 1a). A lithium source was used to contact with the cathode in a wet environment and the lithium ions will go to the cathode by diffusion. The product of pre-lithiation was confirmed to be amorphous Li2S by XPS and XRD analysis. As Figure 1b shows, the first charge capacity can reach 1153 mAh/g (sulfur) at 0.1C rate after paired with a Li foil anode. This Li2S/KB cathode can be coupled with lithium free anode, such as graphite, Si to form a lithium free battery.

Figure 1. (a) Cross section FE-SEM image of the S/KB/PPy cathode. Inset is the FE-SEM image of the PPy layer of the S/KB/PPy cathode. (b) The charge and discharge of the pre-lithiated cathode at a charge rate of 0.1C.

Furthermore, the thickness of PPy was proved to influence the cyclability and capacity of the coin type cell. With the help of PPy, the shuttle effect will be alleviated by the ion-selective property of the PPy layer. Additionally, the lithiated S/KB cathode can be exposed to air for a short time because of the protection of PPy layer. We believe these properties of the lithiated S/KB cathode will provide possibility to assemble Li2S battery in air atmosphere and pave way to commercialization.

Acknowledgement

This work is supported by Advanced Low Carbon Technology Research and Development Program (JST-ALCA) Special Priority Research Area "Next-generation Rechargeable Battery”.

References

1. Manthiram, A.; Fu, Y.; Chung, S. H.; Zu, C.; Su, Y. S. Chem. Rev., 114, 11751-87 (2014).

2. Son, Y.; Lee, J.-S.; Son, Y.; Jang, J.-H.; Cho, J. Adv. Energy Mater., 
5, 1500110 (2015).

3. Nakamura, N.; Yokoshima, T.; Nara, H.; Momma, T.; Osaka, T. J. Power. Sources, 274, 1263-1266 (2015).

Figure 1
Development on High Energy Laminated Type Li Secondary Batteries Using Si-O-C Composite Anode and S/KB Composite Cathode with Glyme-Li Salt Solvate Ionic Liquid
Authors: Jeong Moongook , Yokoshima Tokihiko , Sugiyama Atsushi , Nara Hiroki , Mikuriya Hitoshi , Momma Toshiyuki , Osaka Tetsuya
Published: February 2020

It is well known that sulfur is considered as a new generation cathode active materials of lithium secondary batteries because its abundance in nature, reversible electrochemical reaction with Li ion and very high theoretical specific capacity compared to the established commercial LCO electrodes (Li2S; 1166 mA h g-1, LiCoO2; 274 mA h g-1). We already introduced the Li-S battery prepared by the S/KB composite cathode and Li metal anode delivering high energy density of 200 Wh kg-1. In the previous work, 3D mesh structured Al foam was used as a substrate for the S/KB cathode active material to improve its loading amount. The S/KB composite cathode on the 3D mesh structured Al foam substrate was cycled with Li metal and glyme–Li salt solvate ionic liquid as an anode and an electrolyte. In this study, the S/KB composite cathode loaded on 3D mesh structured Al foam substrate was developed with Si-O-C composite anode. We have previously reported the Si-O-C composite anode which was prepared by electrodeposition technique using organic carbonate electrolyte. [1, 2] The Si-O-C composite achieved highly durable cycle ability with relatively high specific capacity showing 1045 mA h g-1-Si at the 2000th cycle and 842 mA h g-1-Si even at the 7200th cycle. Herein, we used specially treated Cu substrate showing high surface roughness to increase electrodeposited Si amount. The electrodeposited Si-O-C composite anode and the S/KB composite cathode were assembled with a Li activation electrode. The Li activation electrode was inserted for pre-activation process of the S/KB composite cathode and the Si-O-C composite anode. Afterwards, lithium pre-doping process of the full cell was carried out in aid of the Li activation electrode. As the result, we developed high energy laminated type lithium secondary battery using the Si-O-C composite anode and the S/KB composite cathode with glyme–Li salt solvate ionic liquid. Fig. 1 shows potential profiles of the S/KB composite cathode (a) and the Si-O-C composite anode (b) cycled by half-cell assembly for activation process. Furthermore, the loading amount of S/KB active material is succeeded to increase from 1.3 to 11.5 mg cm-2, which shows the promising potential on enlarging capacity of cathode.

Acknowledgements

This work was partly supported by Saitama Leading Edge Project “Development of community energy management system with secondary-batteries control for creating eco-towns”, Saitama Prefecture, Japan

References

[1] H. Nara, T. Yokoshima, T. Momma, T. Osaka, Energy Environ. Sci. 5 (2012) 6500-6505.

[2] T. Osaka, H. Nara, T. Momma, T. Yokoshima, J. Mater. Chem. A 2 (2014) 883-896.

Figure 1
Electrochemical Properties of LiNi0.85Co0.10Al0.05O2 synthesized By Using AAO(Anodic Aluminum Oxide) Template
Authors: Shin Mi-Ra
Published: February 2020

Abstract

Recently, among various cathode materials for lithium batteries, LiCoO2 has been still use on the market due to electrochemical stability. However, LiCoO2 cathode materials have low thermal stability, high cost, low capacity. [1-2] Co and Al co-synthesized materials, Li(Ni,Co,Al)O2, are one of the most applicable materials due to the low cost, thermal stability than LiCoO2. Thus, the battery properties of lithium ion cell with LiNi0.85Co0.10Al0.05O2 cathode are better than LiCoO2. But, LiNi0.85Co0.10Al0.05O2 still show that capacity fading. [3] Anodizing method is an effective means of improving electrochemical performance. To improve the electrochemical properties of cathode material LiNi0.85Co0.10Al0.05O2 for a lithium-ion battery, LiNi0.85Co0.10Al0.05O2 cathode powders were prepared by sol-gel method in AAO template followed by heat treatment. The prepared compounds were characterized by means of X-ray diffraction (XRD), scanning electron microscopy (SEM), atomic force microscopy (AFM) studies and were subjected to charge-discharge cycling performance studies at different C-rates. Though the SEM, AFM, it was confirm that nano-rod for cathode material was obtained. [4]

 

References

[1] T. J. Park, J. B. Lim, and J. T. Son, Bull. Korean Chem. Soc.
2014
, Vol. 35, No. 2 357

[2] Z. R. Chang, X.Z. Yuan and H. Wang, Powder Technology 207 (2011) 396
–
400

[3] H. Kondo, T. Kamiyama and Y. Ukyo, J. Power Sources 174 (2007) 1131–1136

[4] S. B. Yang, C. Kim, B. C. Jang, and J. T. Son, J. Korean Physical Soc. Vol. 67, No.4 728~732

 

Acknowledgement

This study was supported by the granted financial resource from Korea National University of Transportation in 2016, the Ministry of Trade program of the Industry & Energy, Republic of Korea (G02N03620000901) and the Global Excellent Technology Innovation of the Korea Institute of Energy Technology Evaluation and Planning (KETEP).
N-Doped Carbon submicron Spheres Containing Sn Nanoparticles with Homogeneous Distribution As High Performance Anodes for Lithium and Sodium Ion Batteries
Authors: Park Seong Jin
Published: February 2020

In this work, we have synthesized the N-doped carbon submicron spheres containing Sn nanoparticles with homogeneous distribution (Sn/NC) and confirmed their electrochemical properties as anodes for lithium and sodium ion batteries. The poly(MAA/EGDMA)/polydopamine [pMEP] microspheres were used as a N-doped carbon source after heat treatment under N2 atmosphere. The size distribution of Sn nanoparticles embedded in N-doped carbon phase depends on the polydopamine providing the additional chelating sites for Sn precursors. Evenly dispersed Sn nanoparticles in the N-doped carbon sphere were characterized by high resolution transmittance microscopy and focused ion beam scanning electron microscopy. The doped nitrogen in the Sn/NC was analyzed by energy dispersive spectroscopy mapping, X-ray photoelectron spectroscopy and Raman spectroscopy. As anode materials of lithium and sodium ion batteries, Sn/NC electrodes exhibit high capacity and good cyclability.
Synthesis of LiCoO2 Thin Film on the Solid Electrolyte By Electro-Deposition Method -for the Fabrication of All-Solid Lithium Ion Battery-
Authors: Sonoyama Noriyuki , Yoshida Yuki
Published: February 2020

Development of all solid state lithium ion batteries is desired for the prevention of inflammation of battery and increase in the energy density of battery system. But, the cost of current all solid battery system under the development is too high, because the deposition of each layer is carried out mainly by vapor deposition method or sputtering method, those require high vacuum condition. Recently, our group has developed the synthesis method of cathode material thin films composed of nano particles by sintering electrodeposited metal oxide precursor on the Au or carbon substrates. [1, 2] In this paper, we have attempted at synthesizing cathode material LiCoO2 on the surface of Au coated solid electrolyte, Li6.75La3Zr1.75Nb0.25O12 (LLZNb), by electrodeposition and subsequent sintering.

LLZNb was synthesized by solid phase method. Electrodeposition was carried out under a cathodic polarization of 1.7 V in 2M CoSO4 solution at 40˚C with bubbling oxygen gas. Obtained cobalt oxide film was sintered at 650˚C for 12h after dipping LiOH solution. The products were identified by XRD and Raman spectroscopy. The electrochemical properties of deposited film was examined by DC charge-discharge and AC impedance measurement using lithium metal anode at the other side of the electrolyte pellet.

In the figure, the charge-discharge curves of the solid battery synthesized on Au coated LLZNb. It was found that reversible charge-discharge with the capacity of 0.1 µAh can be obtained using this thin film solid battery.

Reference

[1] Z. Quan et. al., J. Power Sources. 244 (2013).

[2] N. Sonoyama et al., Solid State Ionics, 285, 106 (2016).

Figure 1
Fluorolytic Sol-Gel Preparation of a Composite of Lithium Fluoride and Iron Difluoride As a Positive Electrode Material for Lithium Secondary Batteries
Authors: Tawa Shinya , Matsumoto Kazuhiko , Hagiwara Rika
Published: February 2020

A composite of lithium fluoride (LiF) and iron difluoride (FeF2) has been prepared by the reaction of the corresponding metal acetates and anhydrous hydrogen fluoride in ethanol in view of its application as a positive electrode material for lithium secondary batteries. The obtained LiF/FeF2 composite shows weak XRD peaks assigned to LiF and FeF2, and crystallite size is estimated to be 12 nm by the Scherrer’s equation. The composite powder exhibits a high N­2-adsorption capacity with adsorption-desorption loop due to the existence of meso-pores, and BET surface area is calculated to be 119 m2 g−1. In the charge–discharge test, this composite shows an initial charge capacity of 235 mAh (g-LiF/FeF2)−1 and discharge capacity of 225 mAh (g-LiF/FeF2)−1 at 10 mA (g-LiF/FeF2)−
1. Although the discharge reaction from the initial cycle occurs with small overpotential, the charge reaction exhibits large overpotential over 300 mV even at a slow rate below 10 mA (g-LiF/FeF2)−
1.
Lithium Titanium Sulfide Thin Film Cathodes for All-Solid-State Lithium-Ion Batteries: Taking Advantage of a Dual Cation and Anion-Based Redox Process
Authors: Le Cras Frédéric , Flamary Vincent , Dubois Vincent , Martinez Hervé , Pecquenard Brigitte
Published: February 2020

The significant growth of both the number and the kinds of portable electronic systems, generally battery-powered has triggered the race for the development of high-performance microprocessors and systems on chips using low power consumption integrated circuits. As a consequence, the energy supply of such optimized components can also be ensured today by miniaturized power sources such as Li microbatteries. The latter have the advantage of being manufactured by vacuum deposition process also widely used in the microelectronics industry [1]. Nevertheless to be considered as an electronic components, the microbattery need to sustain temperature higher than 230°C for the reflow soldering to attach the component to the PCB . As Li metal anode melts at 181°C, Li microbatteries are not tolerant to such high temperature. For this reason we have manufactured Li-ion all-solid-state thin films batteries based on Si at the negative electrode and a new lithiated titanium oxysulfide as a cathode [2]. Lithium titanium sulphide thin films were synthesized by sputtering of LiTiS2 targets. Three different methods including chemical lithiation, solid state synthesis or spark plasma sintering steps were used to prepare the targets in-house and were found to influence the final composition of the films [3]. Due to the high reactivity of titanium, incorporation of some oxygen into the LiTiS2 film is inevitable. The limited oxygenation of the films that occurs, favours the occurrence of the S2-/(S2)2- redox process at the expense of the Ti3+/Ti4+ one during the battery operation. Finally, a perfect reversibility of both electrochemical processes is highlighted, whatever the initial oxygen content. All-solid-state lithium microbatteries using these amorphous lithiated titanium disulphide thin films and operated between 1.5-3.0 V/Li+/Li deliver a greater capacity (210-270 mAh g-1) than LiCoO2, with a perfect capacity retention (-0.0015 % cycle-1). Excellent electrochemical performances in terms of capacity value and cycling stability were also obtained in all-solid state Li-ion cells with Si as a negative electrode. After three successive solder-reflow processes (thermal treatment at 260°C), the capacity, the cycle life as well as the voltage profile remained unchanged. Finally, Li1.2TiO0.5S2.1 is confirmed as a new interesting lithiated positive material for thin film lithium and lithium-ion microbatteries. Moreover, as its synthesis does not require any thermal treatment (contrary to the well-known LiCoO2), is well-adapted to thermally sensitive substrates such as flexible polymers foils.

References:

[1] B. Fleutot, B. Pecquenard, F. Le Cras, B. Delis, H. Martinez et al., J. Power Sources, 196 (2011) 10289

[2] F. Le Cras, B. Pecquenard, V. Dubois, V.P. Phan et al., Adv.
Energy Mater., 5 (2015) 1501061

[3] V. Dubois, B. Pecquenard, S. Soulé, H. Martinez, F. Le Cras, submitted