bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Beyond Lithium Ion Batteries
Authors: Amine Khalil , Chen Zonghai , Lu Jun 
Published: February 2020

In other to enable 40 miles PHEVs and long electric drive range EVs, there is a need of developing advanced battery systems that offer at least 250 to 300 wh/kg energy density. The challenge is to develop batteries that are able to perform the requirements imposed by a PHEV system and yet meet market expectations in terms of cost and life. In this case, the PHEV battery will experience both deep discharge, like an electric vehicle, and shallow cycling necessary to maintain the battery for power assist in charge sustaining HEV mode.
Conventional lithium-ion batteries based on metal oxides and graphite have made significant progress in recent years for HEV applications, however, durability with the PHEV duty cycle and the ultimate cost and safety of the technology remain key challenges. To achieve a very high all electric drive range, a new battery system is needed. In this talk, we will disclose new systems based on beyond lithium ion chemistry. Li/S batteries have attracted lots of attention because of their low cost and high energy-density. However, the dissolution of lithium polysulfides in non-aqueous electrolytes causes the accelerated capacity fade and low round turn energy efficiency of Li/S batteries during normal charge/discharge cycling. Alternatively, Li/Se has been newly explored to take advantage of extremely low solubility of Li2Se in non-aqueous electrolyte. In situ X-ray absorption spectroscopy at K edge of Se (~12.66 KeV) during the normal charge/discharge cycling of a Li/Se cell clearly shows that Se can be reversibly reduced to Li2Se upon lithium insertion reaction, and can be fully recovered upon the subsequently lithium removal reaction. More progress on Li/Se and Li/SeSx chemistry will be discussed in this talk. We will also disclose new lithium air based on Lithium superoxide and new close system based on lithium oxide/lithium superoxide that offers significantly high energy density.
Investigation on Electrochemical Properties and Degradation Mechanism of Silicon Oxide-Containing Negative Electrode for Li-Ion Rechargeable Battery
Authors: Kobayashi Hironori , Kuratani Kentaro , Shikano Masahiro , Okumura Toyoki , Saito Yoshiyasu 
Published: February 2020

Recently Li-ion rechargeable battery (LIB) has been widely used as power source for not only portable device but also electric vehicle (EV). For EVs, a high-performance LIB with a high energy density is strongly required to increase the mileage. Si-containing materials are promising negative electrode materials for LIB because of large theoretical capacity compared with that of conventional carbon materials. Therefore, a great deal of effort has been made to put Si-containing materials into practical use. However, there are still some problems to be solved.

In this paper, we investigated electrochemical properties of the Si or SiO-containing negative electrodes. We selected the ketjen black as a conductive enhancer and the polyimide-based binder as a binder material, and then tried to fabricate the negative electrode with an excellent cycle property and long life. However, the electrodes where only Si or SiO-containing material was used as the active material showed a rapid decrease in capacity with cycles. Therefore, we fabricated the composite electrode where SiO was composed with graphite in weight ratio of 1:2, 1:1 and 2:1, and checked electrochemical properties using various electrolytes. For the electrode where the weight ratio of SiO and graphite was 1:2, the initial discharge capacities of ca. 596 and 614 mAh/g were observed using 1M LiPF6 in EC:DMC (= 1:2) with and without 5wt% FEC, respectively, for the voltage range of 0.02 and 1.0 V. On the other hands, the reversible discharge capacities of ca. 542 and 244 mAh/g were observed using 1M LiPF6 in EC:DMC (= 1:2) with and without 5wt% FEC, respectively, after 200 cycles. Therefore, it is important to clarify the degradation mechanism due to the difference of the electrolyte for improving cycle proeprty and life.

In the presentation, we will clarify the degradation mechanism of SiO-containing negative electrode by the combination of Li MAS NMR and XPS measurements.

Acknowledgement
This work was partly supported by the New Energy and Industrial Technology Development Organization (NEDO).
Lithium Detection in the Electron Microscope
Authors: Gauvin Raynald , Brodusch Nicolas , Demers Hendrix , Demopoulos George P. , Zaghib Karim 
Published: February 2020

This paper will present the results for the determination of concentration of Li in silicates cathode materials using x-ray microanalysis with windowless SDD EDS technology and with Electron Energy Loss Spectroscopy (EELS) with state of the art field emission scanning electron microscopes at high spatial resolution. Advantages and disadvantages of both techniques will be covered. The aim of this work is to characterize Li concentration variation at the nm scale in batteries materials. The issue of electron beam damage will be covered and the advantage to work at electron beam energies below 30 keV will be demonstrated.
Towards the I
n-Operando Observation of Lithium Dendrite Growth Via X-Ray Computed Tomography
Authors: Frisco Sarah , Liu Danny X. , Mandal Pratiti , Choi Paul , Kedlaya Vinayak , Litster Shawn , Whitacre Jay , Love Corey T , Swider-Lyons Karen 
Published: February 2020

The formation of lithium dendrites causes significant safety concerns in current lithium ion cells and prevents the implementation of commercial lithium metal batteries. To better understand this phenomenon, we are using nanoresolution x-ray computed tomography (nano-CT) to observe the in-operando nucleation and growth of dendrites during lithium deposition. Preliminary results of lithium films deposited ex-situ reveal that different deposition conditions affect not only the surface morphology but also subsurface features. Figure 1 displays the results of cycling the lithium film at high rates: the higher rate sample shows a dramatic increase in thickness and porosity within the film.
The observational cell can also be used to observe other degradation processes occurring within lithium-ion batteries such as the deposition of copper dendrites during an overdischarge event. We will show preliminary results on the effect of deposition conditions (rate, temperature, etc.) on the surface and subsurface morphology of the lithium. From this, we are able to investigate how suppression methods such as electrolyte composition affect these features and develop more targeted strategies at dendrite prevention.

Figure 1
Ssnmr Studies of Li3V2(PO4)3/C Cathode Reactions: Structural Evolution, Dynamics and LVP-Carbon Interface
Authors: Huo Hua , Shao Jinyu , Zhong Guiming , Wu Di , Peng Luming , Yang Yong , Dai Changsong , Xiong Yueping 
Published: February 2020

Monoclinic lithium vanadium phosphate Li3V2 (PO4)3(LVP) is a highly promising cathode material for lithium-ion batteries. In the past decades, extensive efforts have been made to improve the electrochemical performance of LVP by carbon coating and cation doping[1]. In-depth understanding of the local structures and charge-discharge mechanism of LVP can provide valuable information for the design of cation doping or surface modification. SSNMR has been demonstrated a powerful tool of local structure analysis and dynamics. However, due to sever line broadening and signal coalescence caused by the heating effect of carbon in the cathode composite, SSNMR study of LVP material was only limited to samples prepared by chemical delithiation[2], which cannot fully represent the real electrochemical process.
We hereby present the first SSNMR study of LVP/C cathode reaction. The electrodes have been prepared in a binder free and carbon additive free fashion, in order to reduce the heating effect to a minimum during NMR spectra acquisition. A variety of SSNMR techniques have been combined to obtain structural information from different aspects. The structural changes of the polyhedron framework upon delithiation-lithiation were traced by 7Li and 31P NMR. The dynamic processes involving Li exchange and migration were monitored by variable temperature 7Li NMR and EIS technique. 13C-7Li REDOR NMR and HRTEM were performed to investigate Li-O-C connectivity and the short range structure at the LVP-carbon interface. The NMR results have elucidated the driving force of the asymmetric phase formation during charge-discharge within the voltage window of 4.3-4.8 volts and provided experimental evidence of direct chemical bonding between LVP and carbon coating.
Our study helps the battery community to understand the (de)lithiation mechanism of LVP cathode, and more important, the role of carbon coating.
[1]. Rui X, Yan Q, Skyllas-Kazacos M, et al. Li3V2(PO4)3 cathode materials for lithium-ion batteries: A review[J].
J. Power Sources
, 2014, 258(21):19-38.
[2]. Yin S C, Grondey H, Strobel P, et al. Charge ordering in lithium vanadium phosphates: electrode materials for lithium-ion batteries.[J].
J. Am. Chem. Soc.
, 2003, 125(2):326-7.
Self-Terminated Electrodeposition Reactions for Electrocatalysis
Authors: Moffat Thomas P. , Liu Yihua , Ahn Sang Hyun , Wang Rongyue , Ritzert Nicole L. , Gokcen Dincer , Hangarter Carlos , Bertocci Ugo 
Published: February 2020

Development of a sustainable hydrogen economy based on water electrolysis and fuel cells is constrained by the performance, longevity and high cost of Pt group electrocatalysts. Important strategies for improving catalytic reactivity include alloying, forming bimetallic or alloyed surfaces, and engineering substrate–catalyst interactions. At the same time, significant effort is underway to minimize the loading of Pt group metals by examining new synthesis methods and electrode geometries. Of particular interest is atomic layer deposition (ALD) for growing ultrathin films that maximize utilization of rare, expensive metals and facilitate the exploration of bimetallic effects in electrocatalysis.
Recently, an inexpensive “wet form” of ALD based on self-terminated electrodeposition reactions was uncovered that enables controlled formation of ultrathin films of Pt, Ir and Fe-group metals and alloys thereof. The mechanism of self-terminated deposition reactions will be discussed and the utility of these films as bimetallic electrocatalysts will be demonstrated. For example, monolayer equivalent Pt and Ir films were found to match or exceed the best known specific HER/HOR activity for bulk polycrystalline Pt or Ir electrodes and thereby offer the promise of increasing the scalability of these important precious metals in energy conversion devices.
High Mass Activity and Stability of Core-Shell Pd-Ni Nanoparticles Electrodeposited on Diamond Electrodes for Direct Alcohol Fuel Cell Applications
Authors: Mavrokefalos Christos K. , Hasan Maksudul , Rohan James F. , Foord John S. 
Published: February 2020

Sustainable ‘green’ energy applications have received increasing research efforts in the last few years to deal with issues such as climate change, energy shortage and environmental pollution. A subcategory of fuel cells, the direct alcohol fuel cells (DAFCs) have been established in that field due to their ability to convert the chemical energy stored in the fuel into electricity and can be utilised in portable devices and transportation applications. Electrocatalysis is an important aspect in the development of such sustainable technologies. Hybrid materials consisting of graphitic nanostructures and various metal or metal oxide complexes have been widely studied as functional components in catalysis for fuel cell applications. The development core-shell nanostructures and replacing or reducing noble metal content by the incorporation of non-noble metals promises to increase the overall mass activity and improve stability due to electronic interactions with the interfacial layer in the inner shell.
Herein, the electrodeposition of Ni and Pd nanoparticles supported on oxygen terminated boron-doped diamond (OBDD) electrodes is described. The electrochemical modification involves two-steps; first electrodeposition of Ni as nanoparticles on OBDD followed by Pd onto the freshly deposited Ni nanoparticles. SEM imgage of the sequential deposition of Pd-Ni produced nanoparticles in the size range of 10-13 nm is shown in Fig. 1 (a). XPS and electrochemical characterization showed that Ni nanoparticles act as reactive centres on OBDD for the subsequent deposition of Pd to form core-shell nanostructures. The Pd-Ni/OBDD electrocatalysts were evaluated in an alkaline aqueous solution containing ethanol and compared to Pd/OBDD itself. The formation of core-shell nanostructures led to high current responses for ethanol oxidation. The phenomenon is attributed to the improved dispersion of Ni onto the BDD and the electronic interaction between the interfaces of the two metals. Of note is the fact the core-shell catalysts exhibited enhanced mass activity and operational stability. After chronopotentiometric measurements, there was only 12% current drop of the Pd-Ni/OBDD in comparison to 35% current drop of the Pd/OBDD catalyst itself. The Pd-Ni electrocatalysts even with 4 times less palladium loading showed higher amperometric response than the pure Pd/OBDD (Fig. 1(b)). The higher mass activity is likely due to an increased tolerance to carbon based reaction by-products poisoning effects at the bimetallic interface with the transition metal in the inner shell.

Figure
1 (a) SEM image of Pd-Ni modified OBDD electrode (b) Cyclic voltammograms of Pd and Pd-Ni modified OBDD in 0.5 M KOH and 1 M EtOH at a potential scan rate of 100 mV s-1.

Figure 1
Electrodeposited and Oxidized Mn/Co-Fe As Bi-Functional Electrocatalysts for Rechargeable Zinc-Air Batteries
Authors: Xiong Ming , Ivey Douglas G 
Published: February 2020

Electrochemically rechargeable zinc-air batteries are one of the best candidates to store very large amounts of electrical energy[1]. However, due to the sluggish ORR (oxygen reduction reaction) and OER (oxygen evolution reaction) at the air electrode, the efficiency of zinc-air batteries is comparatively low, leading to energy losses. In addition, the stability of the catalysts is poor because they can peel off or pulverize during battery cycling. The air electrode contains a gas diffusion layer (GDL) as the substrate and a catalyst layer. The key to increasing efficiency and stability is to properly combine catalysts with the GDL to facilitate the ORR and OER. Manganese oxides have been shown to be excellent ORR catalysts, while oxidized Co-Fe performs well in catalyzing OER[2,3]. The proper amalgamation of the two materials may be able to generate a highly efficient bi-functional catalyst that can catalyze both ORR and OER.
In this study, Mn and Co-Fe were sequentially electrodeposited onto the GDL and then annealed in air to produce transition metal oxide catalysts. The fabricated material was then assembled into a zinc-air battery as the air electrode component to run battery cycling tests. Scanning electron microscopy (SEM) and energy dispersive X-ray (EDX) results show that a porous Mn-layer was firstly formed on the GDL and then covered by another layer of Co-Fe nanoparticles (Fig. 1). The nanocomposite structure provides a high surface area for electrochemical reactions. The electrocatalytic properties of the bi-functional catalysts were studied by cyclic voltammetry (CV) in 6M KOH solution. The CV results demonstrate that the oxidized Mn/Co-Fe nanocomposite exhibits activities for both ORR and OER. Preliminary cell test results show that the discharge-recharge efficiency is increased from 50% to 58% at 10 mA/cm2 current density when the catalysts are used in the battery. The efficiency can be further improved with optimized catalysts design and fabrication. In addition, the deposited catalyst layer shows strong adhesion to the GDL and excellent stability after 40 hours of battery testing. The influence of electrodeposition conditions on the electrochemical performance is also discussed.

References

1. Y. Li and H. Dai, Chemical Society Reviews, 2014, 43, 5257-5275.
2. K. Zhang, X. Han, Z. Hu, X. Zhang, Z. Tao and J. Chen, Chemical Society Reviews, 2015, 44, 699-728.
3. J. Ahmed, B. Kumar, A. M. Mugweru, P. Trinh, K. V. Ramanujachary, S. E. Lofland and A. K. Ganguli, The Journal of Physical Chemistry C, 2010, 114, 18779-18784.
Fig. 1 SEM image of Co-Fe nanoparticles.

Figure 1
Gas Anodes for Electrowinning of Aluminium
Authors: Mokkelbost Tommy , Khalaghi Babak , Osen Karen Sende , Bai Wei , Kjos Ole Sigmund , Haarberg Geir Martin 
Published: February 2020

Aluminum is today commercial produced by the Hall-Haroult process using consumable carbon anodes. Consumable anodes have several drawbacks such as CO2 emission, continuous anode-cathode distance adjustments and replacements of anodes. Replacing the consumable anodes with inert anodes has been a topic for many decades without commercial success. Using porous inert gas anodes where natural gas or hydrogen take place in the anode reaction has been shown in laboratory tests to reduce the anode potential and reduce the CO2emission. However, formation of water results in evolution hydrogen fluorides which must be solved. Different type of anodes have been prepared and evaluated as possible gas anodes for this concept. Three different graphite materials with different pore sizes and porosity, commercially available, have been used to fabricate gas anodes. Porous SnO2 based materials have been prepared using either foam preforms or coarse SnO2 based particles sintered together with fine SnO2 based powders. These fabrication routes results in significant different materials. The materials are evaluated as possible porous anodes for this concept.
Laboratory experiments using porous depolarized SnO2-based with CH4 and H2-gases have been performed with off-gas analysis and with special attention to hydrogen fluoride evolution. An theoretical mass balance with focus on HF emission has been performed and two different scenarios are presented 1) gas anode process and 2) conventional Hall Heroult cell. In addition we present simulation of the gas transport of a possible industrial gas anode. The challenging side effects of HF emission might be utilized in the process and is discussed.
(Invited) Synergy of Nyquist and Bode Electrochemical Impedance Spectroscopy Studies to Stoba in Lithium Ion Battery
Authors: Wang Fu-Ming , Yang Lyu-Ye 
Published: February 2020

Self Terminated Oligomer Branched Architecture (STOBA) was developed to enhance the safety performance in lithium ion battery. Previous studies [1-3] were shown that the STOBA is able to prevent a short circuit problem when battery suffers nail penetration. However, recent inverstigations indicated that the STOBA is constructed by four reaction mechanisms and only one reaction mechanism is used to increase battery performances including safety and cycle life.
In this study, a new STOBA is initialized owing to the reaction mechanism is purified. According to the Electrochemical Impedeance Spectroscopy (EIS) results, the new STOBA battery system shows the lowest charge transfer resistance at the first and ten cycle. Fig. 1a indicates that the new STOBA with single reaction mechanism provides high ionic diffusivity, which enhances the electrochemcial reaction on interface. In addition, Fig. 1b demonstrates that a passivation layer was formed and is clearly defined in both cases. The impedance of passivation layer in pure lithium-rich layered nickle maganease oxide (LLNMO) reveals 270 ohm and the STOBA inside LLNMO shows only 200 ohm. Figs. 1c and 1d show the Bode polts of both batteries. This result demonstrates the highest Qeff coeffcicent (at 30 Hz) is taking place at STOBA battery system compare with the pure LLNMO battery system, indicating 3D distribution arises from surface heterogeneity. After ten cycles, Fig. 1d shows that STOBA battery system still provides the highest Qeff coeffcicent (at 7 Hz); nevertheless, a sensitive shoulder (at the range of 1.3~0.09 Hz) is discovered at pure LLNMO system, indicating an phase exchange irreversible reaction of bulk material is enclosed. This result indicates the new STOBA inhibits the phase exchange irreversible reaction and provides good performance for further application.
Reference
1. Fu-Ming Wang, Shen-Chuan Lo, Chin-Shu Cheng, Jung-Hsuan Chen, Bing-Joe Hwang, Hung-Chun Wu, J. Membrane Sci 368 (2011) 165
2. Yu-Han, Meng-Lun Lee, Fu-Ming Wang, Chang-Rung Yang, Peter P. J. Chu, Jing-Pin Pan, Electrochim. Acta 85 (2012) 72
3. Yu-Han, Meng-Lun Lee, Fu-Ming Wang, Chang-Rung Yang, Peter P. J. Chu, Jing-Pin Pan, Appl. Sur. Sci. 261 (2012) 306

Figure 1
(Invited) AC Impedance Studies on Electrode/Electrolyte Interface in Lithium-Ion Batteries
Authors: Abe Takeshi 
Published: February 2020

Lithium-ion batteries have been extensively used for portable devices and electric vehicles. For the latter use of lithium-ion batteries, rapid charge is required in addition to long cycle lives, high safety, etc. We have focused on the rate capabilities of lithium-ion batteries by considering the lithium-ion transfer at electrode/electrolyte interface and also ion transport inside composite electrodes.
Lithium-ion transfer at electrode/electrolyte interface was studied by using various model electrodes. Highly oriented pyrolytic graphite (HOPG) was used as a model electrode of graphite negative electrode. Since the basal plane of HOPG has limited reaction sites, we can observe large lithium-ion (charge) transfer resistances by Ac impedance spectroscopy. Then, it is quite easy to evaluate the activation energies for lithium-ion transfer at HOPG electrode. The values are ranging from 50-60 kJ/mol. For the positive electrodes, we used thin films prepared by pulsed laser deposition (PLD). We fabricated LiCoO2 and LiMn2O4 thin film electrodes. By using the thin films, the lithium-ion transfer resistances become also clear. Again, the activation energies were obtained and the values are almost the same with those of graphite.
Based on the activation energies for lithium-ion transfer at negative and positive electrodes, it becomes quite clear that the rate capabilities of lithium-ion batteries at the lower temperature region are quite dependent on the lithium-ion transfer resistances.
We then focused on the ion transfer resistances inside the composite negative and positive electrodes. We used the four-probe cell to evaluate the ion transport resistances inside composite electrodes by Ac impedance spectroscopy. Consequently, the ion transport inside composite electrodes was found to be very slow for the high density electrodes.
By the above results, I will talk about the rate determining steps of lithium-ion batteries at the conference.
Acknowledgment
This work was partially supported by CREST, JST.