bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) B-Doped Pd Catalyst to Boost Formate Production in Electrochemical CO2 Reduction
Authors: Jiang Bei , Zhang Xia-Guang , Jiang Kun , Wu De-Yin , Cai Wen-Bin
Published: February 2020

Facile interconversion between CO2 and formate/formic acid is important for energy storage and conversion and for neutral carbon emission. Boron-doped Pd catalyst (Pd-B/C), which was previously found in our group with a high CO tolerance to facilitate dehydrogenation of formic acid/formate to CO2[1-4], is now explored for electrochemical hydrogenation of CO2 with reference to Pd/C over a wide potential window [5]. Faradaic efficiency of formate (ηHCOO-) in the CO2 reduction reaction (CO2RR) reaches above 70% after 2 h of electrolysis in CO2-saturated 0.1 M KHCO3 at -0.5 V (vs RHE) on Pd-B/C, twelve times higher than that on homemade or commerical Pd/C, leading to a partial formate current of nearly 60 mA mg-1
Pd (ca. 300 mMHCOO- mg-1
Pd) without optimization of the catalyst layer and the substrate. Although the η
HCOO- decreases and the CO faradaic efficiency (η
CO) increases as potential goes more negatively, the competitive selectivity η
HCOO-/ηCO is always higher on Pd-B/C than on Pd/C at all the potentials examined. The density functional theory (DFT) calculation on energetic aspects of CO2RR on modelled Pd(111) surfaces with and without H-adsorbate confirms that B-doping in the Pd subsurface favors more the adsorption of HCOO*, an intermediate for the formic acid pathway than that of *COOH, an intermediate for the CO pathway. Our results reveal that Pd-B/C is a unique bifunctional catalyst for promoting the HCOOH « CO2 cycle [5].

Acknowledgements
：Financial support from the NSFC (grant No. 21733004 and 21473039）and the 973 Program (No. 2015CB932303) of MOST is highly appreciated

References
：

[1] J.Y. Wang, Y.Y. Kang, H. Yang, and W.B. Cai, J. Phys. Chem. C
,
113, 8366 (2009).

[2] K. Jiang, K. Xu, S.Z. Zou, and W.B. Cai, J. Am. Chem. Soc., 136, 4861 (2014).

[3] K. Jiang, J.F. Chang, H. Wang, S. Brimaud, W. Xing, R. J. Behm, and W.B. Cai , ACS Appl. Mater. Interfaces, 8, 7133(2016)

[4] J. S.Yoo, Z.-J. Zhao, J. K. Nørskov, and F. Studt, ACS Catal., 5, 6579 (2015).

[5] M.Z Wang, X.P. Qin, K. Jiang, Y. Dong, M.H. Shao, and W.B. Cai, J. Phys. Chem. C
121
, 3416(2017).

[5] B. Jiang, X.G. Zhang, K. Jiang, D.Y. Wu, W.B. Cai, to be submitted.
Effects of Cations and Anions in Aqueous Solution on the Electroreduction of Carbon Dioxide
Authors: Zhang Qi , Xu Wutao , Liu Yuyu , Zhang Jiujun
Published: February 2020

Electrolyte has a crucial effect on the performance of electrodes in the process of the electrochemical reduction of carbon dioxide (ERC). In this work, we added common cations including SO4
2
-/HSO4
-, NO3
-,H2PO4
-/HPO4
2-/PO4
3-, Cl-, Br-, I-, and CH3COO-) and common metal ions (Li+, Na+, K+, Rb+, Cs+, Mg2+, Ca2+, Sr2+, and Ba2+) in a 0.1M NaHCO3 aqueous solution to investigate the effects of their presence in electrolyte solution on the efficient ERC over single metallic Cu and Sn electrodes. The effect of these ions on the rate of the ERC, the distribution of the products, and the reaction mechanism of electroreduction of CO2 over Cu and Sn electrodes in electrolyte solution were studied. According to experimental results, we will be able to choose the appropriate electrolyte to enhance electrocatalytic activity and stability, and improve the prediction selectivity of single metallic Cu and Sn catalysts.
Catalysts for CO2 Electroreduction to Hydrocarbons and Oxygenates
Authors: Nwabara Uzoma , Verma Sumit , Gewirth Andrew A , Kenis Paul J.A.
Published: February 2020

Rising atmospheric carbon dioxide (CO2) levels and the associated rise in global temperatures have been brought to light as major global concerns. In fact, annual atmospheric CO2 emissions have risen from about 2 Gt to 10 Gt in the last 5 decades.1 Electricity production (via fossil fuel, etc.) is a large contributor, accounting for 37% of total CO2 emissions, and therefore scientists have turned to renewable energy as a mitigation strategy.2,3 Another widely-studied approach has been to reduce CO2 to value-added chemicals and fuels (carbon monoxide, ethanol, formic acid, etc.). Previous works have aimed at increasing the feasibility of the CO2 electroreduction (CO2RR). Being able to improve and control the selectivity of CO2RR would greatly contribute to its industrial application.

Developing thermodynamically efficient and kinetically active catalysts is a key part of CO2RR. Depending on the catalyst or operating conditions, a variety of products can be formed.4 Hydrocarbons and oxygenates, such as ethanol and methanol, are attractive products because of their high-energy density and variability in application.5 For example, methanol is a feedstock for the industrially mature methanol to gasoline (MTG) process, which has a 95% thermal energy conversion efficiency.6 Although some state of the art electrocatalysts for CO2 electroreduction can produce CO and HCOOH at high selectivity (>80%) and energy efficiency (>60%), the selective production of higher hydrocarbons, especially oxygenates such as ethanol and methanol, is still lacking.7

In this talk, we will present examples of various catalysts for the selective electroreduction of CO2 to oxygenates and hydrocarbons using an alkaline flow electrolyzer at ambient conditions. These catalysts include copper supported on metal oxides (Cu/MxOy), copper-based alloys, etc. Electroanalysis results of the Cu/MxOy catalysts include selective production of C1 products (CO and methane) with traces of methanol when compared to copper nanoparticles. The copper-based alloys depict Faradaic efficiencies of up to 75% for C2 products (ethylene and ethanol).

Acknowledgement

We gratefully acknowledge financial support from I2CNER and the SURGE Fellowship for UN.

References

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Oerlemans, J., Science, 2005, 308(5722), 675-677.

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R.M. Jhong, S. Ma, P.J.A. Kenis, Curr. Opin. Chem. Eng., 2013, 2, 191-199.

Ma, M. Sadakiyo, R. Luo, M. Heima, M. Yamauchi, P.J.A. Kenis, J. Power Sources,
2016, 301, 219-228.

L. Spath, D.C. Dayton, NREL/TP-510-34929, 2003.

J. Martin, G.O. Larrazabál, J. Pérez-Ramírez. Green Chem., 2015.
Understanding Electrocatalytic Hydrogenation of Phenol and Benzaldehyde on Platinum Group Metals for Fuel Production
Authors: Singh Nirala , Sanyal Udishnu , Ruehl Griffin , Fulton John , Camaioni Donald , Gutiérrez Tinoco Oliver Y , Campbell Charles , Lercher Johannes A
Published: February 2020

Despite the ability of aqueous-phase electrocatalytic reduction (hydrogenation) to produce fuels,1 pharmaceuticals, food and other commodity chemicals, the mechanisms of the metal-catalyzed reactions are not always well-understood. Understanding these reactions would allow us to develop improved electrocatalysts and processes to enable sustainable production of important fuels and chemicals. One major challenge in understanding the surface electrochemistry is that the characterization of the electrocatalyst surface is difficult in the presence of water. There are several techniques that can be used to understand the reactant coverages (under reacting conditions), and in this talk a brief overview will be given of spectroscopic techniques (including infrared, Raman, X-ray absorption) and cyclic voltammetry as ways to probe the electrocatalyst surface. In this talk, phenol and benzaldehyde hydrogenation (to cyclohexanol and benzyl alcohol, respectively) on Pt/C and Pd/C will be analyzed using i) experimental and theoretical X-ray absorption spectroscopy and ii) cyclic voltammetry to understand reactant coverages and explain observed reaction rates. Understanding these two models reactants will lead to improved electrocatalysis for not only phenol and benzaldehyde, but also similar compounds that exist in in waste bio-oil, which can be converted to transportation fuel-grade hydrocarbons. The effect of applied potential, reactant and product concentration, and pH on both electrocatalyst surface (including adsorbates) and reaction rate will be discussed. A brief discussion of these results with respect to gas-phase hydrogenation will also be included.

References

(1) Song, Y.; Gutiérrez, O. Y.; Herranz, J.; Lercher, J. A. Appl. Catal. B Environ.
2016, 182, 236.
Coral-like Feni(OH)x@Ni Derived from Corrosion of Nickel As an Integrate Electrode for Efficient Overall Water Splitting
Authors: Xiang Rui , Wei Zi Dong
Published: February 2020

Noble-metal-free, efficient and stable bifunctional catalysts capable of catalyzing oxygen evolution reaction (OER) and hydrogen evolution reaction (HER) are eagerly desired for the commercialization of water splitting electrolysers. Bimetal iron/nickel hydroxide represents a promising water splitting catalyst for its high intrinsic activity, high stability, low cost and nontoxic. To enhance its conductivity and density of active sits, we proposed a mild corrosion assisted protocol to composite FeNi(OH)x nano-sheets with coral-like Ni. These nanosheets together with the electrodeposited coral-like Ni skeleton and the supermacroporous Ni foam substrate constituted a binder-free hierarchical electrode architecture, which is beneficial for exposing catalytic active sites, enhancing mass transport and accelerating dissipation of gaseous species. In 1.0 M KOH solution, the rational designed electrode presented not only magnificent OER catalytic performance with a low overpotential to reach 50 mA cm-2 (η = 254 mV), excellent kinetic (Tafel slop of 45 mV dec-1) and favorable durability, but also superior HER catalytic capability with high activity (η = 68 mV at 10 mA cm-2) and stability. In addition, a symmetric alkaline electrolyser constructed with FeNi(OH)x/Ni as both anode and cathode exhibited better activity (cell voltage of 1.52 V at 10 mA cm-2) than that of the precious metal based couple (i.e. RuO2 - 20 wt% Pt), making FeNi(OH)x/Ni to be a fascinating candidate for overall water splitting.

Key words: Overall water splitting, Integrate electrode, electro-catalysis

Figure 1
(Invited) Operando X-Ray Absorption Investigations into the Oxygen Evolution Activity, Stability, and pH Dependency of NixFe1-XOy Nanoparticles
Authors: Abbott Daniel F. , Fabbri Emiliana , Borlaf Mario , Bozza Francesco , Graule Thomas , Schmidt Thomas J.
Published: February 2020

Mixed Ni-Fe metal oxides currently represent some of the most attractive anode catalysts for the electrochemical splitting of water due to their low overpotentials for the oxygen evolution reaction (OER) in alkaline electrolytes. The concentrated potassium hydroxide solutions and anion exchange membranes that are typically employed in alkaline water electrolyzers, however, are prone to carbonation which can lead to significant shifts in the electrolyte pH from alkaline to quasi-neutral conditions (pH = 7-10). So far a fundamental understanding of how changes in the local pH environment induced via carbonation affect the catalyst electronic and surface structure, and ultimately the catalyst stability and electrochemical OER activity, is lacking. The importance of understanding this behavior is further highlighted by the potential application of Ni-Fe oxides as anode catalysts in co-electrolysis, where the electrochemical reduction of CO2 and the anodic evolution of oxygen occur in a carbonated, quasi-neutral pH environment.

Here we demonstrate a practical and scalable flame-spray pyrolysis synthesis capable of producing highly crystalline Ni-Fe oxide (Ni1-xFexOy) nanoparticles with high surface areas (SABET ≈ 20 - 75 m2/g). The research presented herein focuses on expanding the current understanding of the influence of the local electronic and surface structures on the OER activity and electrochemical stability in both alkaline (pH = 13) and carbonated, quasi-neutral (pH = 9) electrolyte. The resulting operando XANES and EXAFS analyses of the Ni and Fe K-edges permit useful insight into the nature of the valence states and rearrangements in local structure that occur under operating conditions representative of alkaline water electrolysis and co-electrolysis. Combined with a broad range of ex situ physical characterization techniques, we then relate the structural, electronic, and morphological changes to the observed electrochemical OER activity and stability.
Magnesium Perfluoroalkoxyaluminate As a High-Voltage Mg Electrolyte
Authors: Lau Ka-Cheong , Hahn Nathan T , Seguin Trevor , Carino Emily , Connell Justin Grant , Ingram Brian J. , Zavadil Kevin R , Persson Kristin A , Liao Chen
Published: February 2020

In the search for future beyond-Li-ion batteries, Mg batteries present a safe option due to lower pyrophoricity and no formation of dendrites during electrodeposition and dissolution. However, the practical voltage window of Mg batteries is limited by the paucity of both cathodically and anodically stable electrolytes. Recently, carborane,1,2 fluoroalkoxyaluminate3 and fluoroalkoxyborate-based4 electrolytes emerged as potential candidates for high-voltage Mg electrolytes. Inspired by the latter work, we demonstrate in this presentation that magnesium perfluoroalkoxyaluminate as a Mg electrolyte can be rationally designed and synthesized to exhibit unprecedented anodic stability while retaining the capability of Mg electrodeposition and dissolution. Synthesis, spectroscopic characterization and electrochemistry of the electrolyte will be discussed.

Tutusaus, R. Mohtadi, T. S. Arthur, F. Mizuno, E. G. Nelson and Y. V. Sevryugina, Angew. Chem. Int. Ed.
54, 7900 (2015).

G. McArthur, L. Geng, J. Guo and V. Lavallo, Inorg. Chem. Front.
2, 1101 (2015).

T. Herb, C. A. Nist-Lund and C. B. Arnold, ACS Energy Lett.
1, 1227 (2016).

Zhao-Karger, M. E. G. Bardaji, O. Fuhr and M. Fichtner, J. Mater. Chem. A
5, 10815 (2017).
Chemical Imaging Analysis of Solid-Electrolyte Interphase Layer in Li-S Battery
Authors: Murugesan Vijayakumar , Han Kee Sung , Shutthanandan Vaithiyalingam , Thevuthasan Suntharampillai , Mueller Karl T
Published: February 2020

Elemental sulfur, an abundant and low toxicity material, is emerging as a promising cathode material due to higher theoretical specific capacity compared with traditional metal oxides used in Li-ion batteries. Lithium-Sulfur (Li-S) batteries rely on the reduction of sulfur (S8) to lithium sulfide (Li2S) through gradual evolution of polysulfide (Li2S
n
) during the discharge process. Many of the intermediate polysulfide species (Li2S
n
; 4 ≤ n ≤ 8) are highly soluble in electrolyte solvents, leading to cathode corrosion and capacity loss. The dissolved polysulfide species shuttle towards the reactive Li-anode, and accelerates Li anode poisoning through highly a complex solid-electrolyte interphase (SEI) layer formation. The SEI layer is generated by complex interfacial reactions involving transient species/structures; the challenge is to detect, identify and quantify these reactions, which typically span a wide spatial and temporal region and are inaccessible by any single spectroscopic and/or classical computational method. Traditional ex-situ spectroscopic capabilities1-4 often fail to capture critical transient and metastable species which dictate the SEI layer evolution. Hence, it is critical to develop in situ multimodal approaches that can provide unprecedented chemical imaging of these complex interfaces5. In this presentation, we will discuss our recent in-situ X-ray photoelectron spectroscopy (XPS) analysis which yielded an unparalleled view of the chemical speciation and microscopic evolution of the SEI layer (see Figure 1). In combination with computational modeling these data provided a method to establish quantitative understanding of complex interfacial interactions in Li-S batteries.

References:

J. Chen, K. S. Han, W. A. Henderson, K. C. Lau, M. Vijayakumar, T. Dzwiniel, H. Pan, L. A. Curtiss, J. Xiao and K. T. Mueller, Advanced Energy Materials 6 (11) (2016).

H. Pan, K. S. Han, M. Vijayakumar, J. Xiao, R. Cao, J. Chen, J. Zhang, K. T. Mueller, Y. Shao and J. Liu, ACS Applied Materials & Interfaces 9 (5), 4290-4295 (2017).

N. N. Rajput, V. Murugesan, Y. Shin, K. S. Han, K. C. Lau, J. Chen, J. Liu, L. A. Curtiss, K. T. Mueller and K. A. Persson, Chemistry of Materials 29 (8), 3375-3379 (2017).

M. Vijayakumar, N. Govind, E. Walter, S. D. Burton, A. Shukla, A. Devaraj, J. Xiao, J. Liu, C. Wang, A. Karim and S. Thevuthasan, Physical Chemistry Chemical Physics 16 (22), 10923-10932 (2014).

M. I. Nandasiri, L. E. Camacho-Forero, A. M. Schwarz, V. Shutthanandan, S. Thevuthasan, P. B. Balbuena, K. T. Mueller and V. Murugesan, Chemistry of Materials 29 (11), 4728-4737 (2017).

Figure 1
Role of Structural Dynamics on Lithium Diffusion in Li10GeP2S12 (LGPS) and Li3PS4 (LPS) Solid Electrolytes
Authors: Hall Alex Thomas , Adelstein Nicole
Published: February 2020

The search for an ideal solid electrolyte for a safe, long-lasting all-solid battery has been extenstive, but the fundamentals of lithium diffusion are still not completely understood. One of the fastest electrolyte that has been found in lithium germanium thiophosphate, though is electrolyte cannot be used in batteries due to instability with the electrodes. While significant computational research has been done on LGPS, nuances of the mechanisms are still unknown. Insight into the extraordinary conductivity of LGPS, will enable the engineering and search for new electrolyte materials.

Polarization of anions and tetrahedral moieties and rotation analysis were studied in order to elucidate the conductivity difference in LGPS and LPS solid electrolytes. LPS has orders of magnitude lower conductivity than LGPS, but a very similar composition and structure. These analyses allow quantification of the effect of electronic structure and correlated motion on lithium diffusion. Polarization and rotation events were extracted from Density Functional Theory Molecular Dynamics (DFT-MD) simulations. Detailed analysis of the MD simulations revealed that the interaction of lithium with the lattice affects diffusion through the polarization and rotation of the tetrahedral anions. The GeS4 behaves differently than the PS4, which increases the diffisivity in LGPS compared to LPS.
Exfoliated Transition Metal Dichalcogenide Nanosheets for Sodium Ion Batteries and Supercapacitors
Authors: David Lamuel , Mukherjee Santanu , Abass Monsur , Singh Gurpreet
Published: February 2020

With the existing drawbacks of the Li ion batteries (LIBs) in terms of expenditure and safety, there is an increasing research focus on Na ion batteries (NIBs) as a viable replacement especially for large scale grid storage applications. Considering the rather bulky Na ion and the challenges it would pose for efficient reversibility, choice of optimum electrode materials is of significance. Among the various types of materials being considered for applications as the negative electrode, 2-dimensional (2D) transition metal dichalcogenides (TMDs) have elicited interest due to their layered structure and existing in a range of compositions. Among the various TMDs that have been studied, MoS2 has received the most focus due to its excellent cyclability as well as stability, however, others in the TMD family have not received as much focus.

In this work, we study the sodium recycling properties of exfoliated TMD (MoSe2, WSe2 and MoTe2)- reduced graphene oxide (rGO) composite. Electrochemical analysis was performed by using the TMDs in coin cells with Na foil being the counter electrode in organic electrolyte within a cycling window of 2.25 V – 10 mV. Cell cycling results have indicated that WSe2 electrode performed the best and provided a reversible capacity more than 250 mAhg-1 whereas pristine rGO demonstrated only about 80 mAhg-1.

Also, all the TMD/rGO composite electrodes demonstrated a first cycle efficiency greater than 50 %. Similarly, capacity retention results demonstrate a similar pattern, with WSe2 exhibiting about 80 % capacity retention followed by MoSe2 (∼60 %) and MoTe2 (∼45%). Results in aqueous media exhibit similar trends.

In conclusion, it can be said that different 2D layered TMDs have shown promise for application as negative electrodes in NIBs in organic and aqueous environment. This provides hope in their extensive application as stable, high reversible capacity negative electrode materials in NIBs.
Double-Nets Enclosed Sulfur Composite As a New Cathode in Lithium Sulfur Batteries
Authors: Niu Junjie
Published: February 2020

Most of efforts on physical confinements of lithium polysulfides to kinetically slow down the ‘shuttling effect’ in Li-S batteries have been tried to date. However, to avoid the thermodynamic loss of the sulfides, a stronger bonding particularly with a chemical bonding displays more effective way to mitigate the ‘flow away’ process. Here we created a double-nets matrix, which is composed of a low cost, mesoporous activated carbon (AC) and a covered nanoporous oxide cap. The oxide cap not only efficiently ‘blocks’ the sulfide molecular, but also chemically bonds the molecular that greatly delays the diffusion of the sulfide, thus leading to a high capacity retention. The initial capacity of 1600 mAh/g was achieved, which is close to the theoretical capacity. An excellent capacity retention with >900 mAh/g and >705 mAh/g were obtained after 500 cycles at 0.2 and 0.5 C, respectively. At a higher rate of 2.0 C, a capacity of as high as 470 mAh/g was still maintained after 500 cycles, which still keeps a capacity of >400 mAh/g after 1000 cycles with a Coulombic efficiency of 99.8%. Further, a wide range of sulfur ratio of the composite is from 47% up to 73%, enabling a high loading of active material up to >5.0 mg/cm2. This outstanding cycling performance is attributed to the double-nets physical and chemical confinements. The current high cycling and rate performance of the Li-S battery using industry available AC and sulfur provide a high potential in mass production for broad applications of potable electronic devices.
Enable High Initial Coulombic Efficiency for Lithium Battery Anode By Ultrathin Polymer Electrolyte Coating
Authors: Wang Shaofei , Gao Yifan , Shen Brian H , Tenhaeff Wyatt
Published: February 2020

The current lithium battery anodes (graphite and graphite-silicon composite) suffer from low initial coulombic efficiency and low charging rate at low temperature. To address these issues, uniform stable solid electrolyte interphase (SEI) and higher ionic transference number are of primary importance. Recent advancements of nanoscale polymer coating open a new way in surface optimization for better performance. Initiated chemical vapor deposition ((iCVD) could achieve uniform nanoscale polymer coating on the porous substrate, which can enable the large-scale coating on battery electrode sheet. Here, ultrathin conformal coating of the Poly(methacrylic acid) (PMAA) polymer is achieved on graphite electrode by iCVD. Then, Ion-exchange is conducted to form the lithium polymer electrolyte. The high ionic transference number of the polymer electrolyte would significantly reduce the ionic polarization at the electrochemical interface, enabling the higher initial coulombic efficiency and power performance at low temperature. The cycling performance was also significantly improved due to the uniform nanoscaled polymer coating.
Computational Study of Surface Reactivity and Metal Dissolution in LixNi0.5Mn1.5O4-Δ
Authors: Klyukin Konstantin , Intan Nadia N , Alexandrov Vitaly
Published: February 2020

Understanding surface chemistry of Li-ion battery (LIB) cathode materials is crucial for improving their performance. Decomposition of electrolyte and dissolution of transition metal species are interfacial processes both playing key roles in the formation of solid electrolyte interphase (SEI) and contributing to LIB degradation. Here, we focus on spinel LixNi0.5Mn1.5O4-δ as a promising high-voltage cathode material for LIB. By employing a combination of static DFT and enhanced ab initio molecular dynamics (AIMD) approaches we investigate adsorption/decomposition of electrolyte species (e.g., dimethylcarbonate) and kinetics/mechanism of Mn and Ni dissolution into the electrolyte solution. Specifically, we analyze the roles of surface disproportionation reactions and transition metal oxidation states, lithiation/delithiation and formation of oxygen vacancies to identify factors controlling adsorption and dissolution processes.
Mechanically Milled Si-Mn-Fe Alloys as Negative Electrodes for Li-Ion Batteries
Authors: Cao Yidan , Scott Ben , Dunlap R. A. , Obrovac M. N.
Published: February 2020

The theoretical volumetric capacity of silicon (2194 Ah/L) is much larger than that of graphite (756 Ah/L). However, the large volume expansion of silicon is still a main concern for practical utilization. One method of reducing the volume expansion of Si is to alloy it with an inactive element. Both iron and manganese are cheap and abundant transition metals and are therefore interesting candidate inactive alloying metals for silicon based anodes. The binary systems, including Si-Fe and Si-Mn, have been previously studied in our group and by others. It has been found that adding Mn or Fe to Si reduces volume expansion during lithiation by forming inactive phases with Si and by inhibiting Li15Si4 formation. The silicides of Fe and Mn are different in structure and stoichiometry. Ball milled alloys in the Si-Fe-Mn ternary system have not been previously reported. Therefore it is meaningful to investigate the Si-Fe-Mn ternary system.

Here, Si100-x-y
Mn
x
Fe
y
((x,y)=(0,15), (5,12), (10,9), (15,6), (20,3), (25,0)) alloys were prepared by ball milling and their phase composition, microstructure and electrochemistry in Li half cells were studied. The XRD results show that α-Si2Fe and β-Si2Fe are formed in low Mn content samples, i.e. Si85Fe15, Si83Mn5Fe12. As the Mn content is increased, only Si19Mn11 phase is detected. However, the continuous peak shifts in XRD profiles and Mossbauer spectroscopy, shown in Figure 1, demonstrate that Fe atoms are present in the Si19Mn11 structure, to form ternary solid solutions.

The potential and differential capacity curves of Si100-x-y
Mn
x
Fe
y
alloys are typical of alloys in which Si is the only active phase. The formation of Li15Si4 is successfully suppressed in all the samples in the initial cycles. However, Li15Si4 forms after about 10 cycles, as shown in Figure 2. The volumetric capacity and volume expansion of the materials increase with increasing silicon ratio, as shown in Figure 3. In this presentation the composition, microstructure and electrochemistry of alloys in the Si-Mn-Fe system will be thoroughly discussed.

Figure 1
Electrolytes for Safe and Stable Cycling of 4-V Class Lithium Metal Batteries
Authors: Chen Shuru , Zheng Jianming , Yu Lu , Ren Xiaodi , Liu Jun , Xu Wu , Zhang Ji-Guang
Published: February 2020

With the rapid maturation of the state-of-the-art lithium (Li) ion batteries (LIBs), rechargeable Li metal batteries (LMBs) have been regarded as the “holy grail” for the next generation of high-energy storage systems. [1] However, their practical application is hindered by low Coulombic efficiency (CE) and safety concerns due to unstable Li|electrolyte interface and dendrite growth in Li metal anodes (LMAs) during cycling. [2] Some high concentration electrolytes (HCEs) are stable with Li and lead to high CE of Li metal anode (LMA), but their practical applications are still hindered by high cost, high viscosity, and poor wetting capability to cathodes. [3] With addition of selected co-solvents to HCEs, we recently developed some new dilute electrolytes that enable stable cycling of LMAs with CE over 99% and 4-V class cathodes (e.g., NMC). The new dilute electrolytes can thus overcome these drawbacks while maintaining or even enhancing the advantages of HCEs. In addition, these electrolytes are non-flammable. Therefore, they are good candidates to be used for safe and high-energy rechargeable LMBs.

J. M. Tarascon and M. Armand, Nature
414, 359–367 (2001).

J.-G. Zhang, W. Xu and W. A., Henderson, Lithium Metal Anode and Rechargeable Li Metal Batteries. (Springer International Publishing), 249, (2017).

J. Zheng, J. A. Lochala, A. Kwok, Z. D. Deng and J. Xiao, Adv. Sci., 1700032, (2017).
Synthesis of Composite Silicon-Core Graphite-Shell Powders for Application in High-Performance Lithium-Ion Battery Anodes
Authors: Nava Giorgio , Schwan Joseph , Mangolini Lorenzo
Published: February 2020

ABSTRACT WITHDRAWN
Design and Novel Synthesis of Tailored Si@Void@C Nanostructures with Long Cycle Life for Next-Generation Li-Ion Batteries
Authors: He Qianran , Ashuri Maziar , Shaw Leon
Published: February 2020

A facile and low cost method has been investigated in this study to prepare silicon nanoparticles with a conductive carbon shell and engineered voids as anode materials for lithium ion batteries. Several carbon-coating methods have been tried to form a hard and dense carbon shell, while partial etching of Si has been investigated with various etching chemicals and conditions to create engineered voids inside the carbon coated Si nanoparticles. It is demonstrated that the electrochemical performance and cycle stability of Si@void@C depends strongly on synthesis conditions, especially the engineered voids in their structure and composition control in the final product. The higher the Si-to-carbon ratio, the higher discharge capacity it could achieve. Further, as the volume of the engineered void increases, the cycle stability improves. The best properties obtained from these tailored Si@void@C nanostructures are about 3100 mAh/g of specific discharge capacity at the first cycle, and 2500 mAh/g after 300 cycles at the current density of 0.5 A/g. The cycling experiment is still on-going and thus one can expect longer cycle life from these tailored Si@void@C nanostructures.
Protein-Based Biomaterial Enhances Lithium Ion Battery Performance
Authors: Yuan Mengying , Ardebili Haleh
Published: February 2020

The rapid development of potable and flexible electronic devices has accelerated the need for flexible lithium ion batteries based on solid electrolytes. Solid polymer electrolyte based batteries offer many advantages including higher stability, safety, and mechanical flexibility; however, two main issues remain including the lower bulk ion conductivity and the higher solid-to-solid interfacial impedance. This study focuses on the use of protein-based biomaterial to improve the battery performance. Most proteins are intrinsically surface-active molecules due to their large amphiphatic molecules and have the potential to improve interfacial adhesion. Results of this study demonstrate that the added protein-based biomaterial effectively improves and lowers the interfacial impedance, and increases the capacity of the battery.
Black TiO2-X Coated Graphite Anode Materials with Fast Charging Capability for Lithium-Ion Battery
Authors: Kim Dae Sik , Kim Yeong Eun , Lee Dong Geun , Jeong Goojin , Kim Hansu
Published: February 2020

Along with the rapid growth in robots, mobile electronics and electric vehicles (EVs) technology, lithium ion batteries (LIBs) are facing several technical challenges such as higher energy density and fast charging capability. Graphite, currently used anode materials for LIBs, has technical limitations to be used for robots, mobile electronics and EVs in terms of energy density and fast charging capability. To solve these problems, various anode materials have been suggested for alternative graphite anode material. In this work, black titanium dioxide coated graphite was investigated as an anode material with fast charging capability for LIBs. The proposed core-shell structure, black titanium dioxide coated graphite anode electrode exhibited an excellent rate capability of 96.4 % of the capacity retention at a rate of 10 C compare to that tested at a rate of 0.2 C without any degradation of reversible capacity and long-term cycle performance. The characterization, microstructure and electrochemical properties of the black titanium dioxide coated graphite will be discussed in more detail.
High Performance Na–CuCl2 Secondary Battery Using Sulfur Dioxide Based Inorganic Liquid Electrolyte
Authors: Kim Ayoung , Kim Hyun Jong , Lee Dong Geun , Jeong Goojin , Kim Young-Jun , Kim Hansu
Published: February 2020

Na rechargeable batteries have gained much attention as alternative power sources to replace Li rechargeable batteries. However, Na rechargeable batteries need to be further advanced to successfully penetrate rechargeable battery market because of their low energy density and poor reliability. Here, we demonstrate a new type of room temperature Na rechargeable battery that employs CuCl2/C nanocomposite cathode material and SO2-based inorganic liquid electrolyte. The cell delivered a high discharge capacity of 200 mAh g−1, corresponding to a theoretical energy density of 580 Wh kg−1. It also showed a high round-trip energy efficiency (>96%) and remarkable cycle-life over 1000 cycles, which has never been obtained in an organic electrolyte system. These excellent electrochemical performances are mainly attributed to the use of the SO2-based electrolyte, which guarantees a reversible conversion reaction between CuCl2 and CuCl with NaCl. The detailed reaction mechanism of this new battery system will be also discussed in this presentation.
Multiscale In-Situ and Ex-Situ Microscopy and Spectroscopy Diagnosis Guided Designing of Electrode Materials for Better Battery
Authors: Wang Chongmin
Published: February 2020

In-situ diagnosis appears to be one of the essential methods for gaining insights as how an electrode material failure, therefore feeding back for designing and creating new materials with enhanced battery performances. In this presentation, I will highlight recent progress on ex-situ, in-situ and operando S/TEM for probing into the structural and chemical evolution of energy storage materials. Both ex-situ and in-situ high resolution imaging enables direct observation of structural evolution, phase transformation and their correlation with mass, charge and electron transport, providing insights as how active materials failure during the cyclic charging and discharging of a battery. In particular, I will broadly cover the frontier of the current understanding of the fading mechanism of layer structured cathode. Subsequently, I will discuss some recent breakthrough experiments/observations for correlating the structural/chemical evolution with the electrochemical properties of this category of materials and their implications. In perspective, my presentation will target to stimulate this field of research to re-check what has been understood and what need to be done to tackle the technical challenges facing the application of the layer structured cathode materials.
Electrochemical Properties and Interfacial Behavior of All Solid State Batteries Using Li10SnP2S12 Solid Electrolyte
Authors: Vinado Carolina , Wang Shanyu , Li Yun , Xiao Xingcheng , Yang Jihui
Published: February 2020

Thio-LISICON Li10GeP2S12 equivalent Li10SnP2S12 (LSPS) is comparable in ionic conductivity yet with a lower cost as an electrolyte for all solid state batteries (ASSBs). ASSBs with Li10SnP2S12 electrolyte, lithium-indium alloy anode, and LiCoO2 cathode were fabricated and their electrochemical performance at 60 °C was examined. Atomic layer deposition of Li3NbO4 on LiCoO2 was conducted to improve the interfacial stability. The Li3NbO4 coating significantly improves the cycle stability of the ASSB, which retains about 90% initial capacity after 60 cycles at a current density of 0.13 mA/cm2, while the ASSB with uncoated LiCoO2 loses ~ 35% initial capacity after 50 cycles. Electrochemical impedance spectroscopy test indicates a rapid growth of charge transfer resistance upon cycling for the cell with the uncoated LiCoO2, primarily due to the surface instability and build-up of a space charge layer between LSPS and LiCoO2. However, the ASSBs with Li3NbO4 coated LiCoO2 show a more stable interface with a negligible impedance increase upon cycling, attributable to the ‘buffering’ and ‘passivating’ roles of the Li3NbO4 coating. The interfacial microstructure was analyzed to elucidate the underlying reasons for the impedance increase and the pivotal role of Li3NbO4 coating. Our study indicates that surface coating significantly improves the cycle stability of the ASSBs with LSPS as the electrolyte.
(A03 Best Poster Winner) Ammonium Intercalation Chemistry in Prussian Blue Analogues for Energy Storage
Authors: Wu Xianyong , Qi Yitong , Hong Jessica , Jiang Heng , Hernandez Alexandre , Ji Xiulei
Published: February 2020

Aqueous rechargeable batteries (ARBs) represent one of the most promising solutions for stationary energy storage, owing to their intrinsic low cost, high safety and environmental friendliness. To date, most attention has been paid to metal cations as charge carriers, such as Li+, Na+, K+, Mg2+, Zn2+ etc.; however, non-metal cations like hydronium (H3O+) and ammonium (NH4
+) ions received rare attention from the battery community. In this work, we revealed the unique intercalation chemistry of NH4
+ ions in Prussian blue analogues (PBAs), and proposed a “rocking-chair” NH4
+-ion battery in full cell configuration. Comparative studies showed that Berlin green Fe[Fe(CN)6] lattice could demonstrate the highest reaction potential, lowest structural strain and best cycling performance for NH4
+ intercalation than Na+ and K+ ions. We then prepared an ammonium-containing Prussian white analogue, (NH4)2Ni[Fe(CN)6], by a facile ion-exchange method. When coupled with an organic solid, perylenetetracarboxylic diimide (PTCDI), this aqueous NH4
+-ion full cell can deliver a working voltage of ~1.0 V, an energy density of ~43 Wh kg-1 and impressive cycling performance of 1000 cycles. These results may open a new avenue for NH4
+-based energy storage applications.
Tungsten Oxide for Proton Batteries and Its Storage Mechanism
Authors: Jiang Heng , Hong Jessica , Wu Xianyong , Ji Xiulei
Published: February 2020

The proton insertion capability of a new composite, tungsten oxide hydrate, WO3•0.6H2O, synthesized in a simple hydrothermal method is demonstrated as an anode material for rechargeable proton batteries using sulfuric acid as the electrolyte. Using Ag/AgCl and active carbon as the reference electrode and counter electrode respectively, the electrochemical performance of WO3•0.6H2O was carried out by using a three electrode cell. The cell shows a reversible proton insertion/extraction reaction with a charge capacity of 90 mAh/g at a rate of 1C, with an average discharge voltage at -0.25 V (vs. Ag/AgCl). The cycling performance tested at 20C, the charge capacity is still stable at 80 mAh/g after 10,000 cycles. XRD rietveld refinement indicates that WO3•0.6H2O is a channel hexagonal structure and the zeolitic waters are located in the center of the interstitial cavities. Ex-situ XRD studies also confirms that the protons are inserted through the bridge oxygen which causes the expansion of the ab plane and shrinkage in the c direction. Pairing it with Prussian blue (Fe/Fe), a 1.5V full proton cell was made and showed a capacity around 50mAh/g (based on the anode) at current rate of 2Ag-1
. These results demonstrate that WO3•0.6H2O is a promising anode material to be utilized for proton batteries.
State-of-Health Estimation of Lithium-Ion Batteries Based on Partial Charging Voltage Profiles
Authors: Stroe Daniel Ioan , Knap Vaclav , Schaltz Erik
Published: February 2020

Lithium-ion batteries have developed as the key energy storage solutions for various applications from power tools and consumers’ applications to electric vehicles and a renewable energy storage applications. Besides offering better performance (e.g., high gravimetric and volumetric energy density, high power capability during both charging and discharging, long lifetime) in comparison to other energy storage devices, Lithium-ion batteries are non-linear systems with their performance and degradation behavior strongly dependent on the operating conditions [1]. Thus, knowledge about the battery state-of-health (SOH) has become mandatory for real-life applications. Consequently, the topic of Lithium-ion battery was brought at the forefront of the research.

Many battery SOH estimation methods were developed and are available in the literature [2]. Most of these methods, which show very good accuracy, are applicable and validated only for perfect laboratory testing conditions. However, in real-life applications, the batteries are subjected to various constraints imposed by the battery management system (BMS); the constraints refer among others to impossibility of applying high current peaks to measure the internal resistance, discharge the battery to measure the capacity by other means then driving the car and/or have access to the whole battery voltage window to measure the battery capacity.

Thus, in this paper we proposed a method for estimating the SOH of the battery, which focuses on the measurement of the battery capacity for a certain voltage interval (e.g., 10%-90% SOC), which is not the entire voltage window allowed by the manufacturer as presented in Figure 1 and Figure 2. The proposed SOH estimation method is applied and its accuracy is assessed to different Li-ion battery chemistries.

[1] M. Kassem, J. Bernard, R. Revel, S. Pelissier, F. Duclaud, C. Delacourt, J. of Power Sources, 208, 296-305, (2012)

[2] M. Berecibar et al., Renewable and Sustainable Energy Reviews, 56, 572-587 (2016).

Figure 1
New Artificial Interphase with Li-Ion Pathway between Li Metal and Electrolytes for Secure Lithium Metal Anodes
Authors: Lee Jung-In , Shin Myoungsoo , Park Soojin
Published: February 2020

While Li-ion batteries were firstly studied with Li metal as anodes due to its high theoretical specific capacity (3860 mA h g-1) and lowest negative electrochemical potential (-3.040 V vs SHE), commercial Li-ion batteries since 1992 consisted of graphite as an anode because of critical safety issues. However, for several decades, many strategies have been developed to surmount difficulties like problems of dendrite growth using modifications of electrolytes with additives, a change of lithium metal morphology, and an introduction of chemical/physical coating layers on Li metal.

Herein, we report a simple approach to improve the electrochemical performance of Li metal anodes in Li-ion batteries with commercial carbonate-based electrolytes by utilizing a high Li-ion conductor, Li2TiO3, on Li metal anodes. Monoclinic Li2TiO3 is electrochemically inert in a wide voltage range with excellent structural stability in a liquid electrolyte. In addition, it structurally has a 3D path for Li-ion diffusions, leading to more uniform Li-ion flux. Li2TiO3 nanoparticles with a size of sub-100 nm were synthesized via a sol-gel method, and then the resulting particles were mixed with carbon as a conducting material and PVDF-HFP as a binder. A bright Li metal surface was covered with gray Li2TiO3 films in Figure 1a. From various Li plating and striping tests with pristine and modified Li metal as working electrodes, the modified Li metal exhibited outstanding electrochemical performances such as stable coulombic efficiency over 100th cycles at 1 mA/cm2 as shown in Figure 1c. Moreover, the modified Li metal was applied for practical lithium-ion batteries as a counter electrode to confirm the protective effects with LMO as a working electrode at a room temperature (25 oC) and high temperature (60 oC).

Figure 1
Approaches to Complex Electrolyte Formulation Optimization
Authors: Cheng Gang , Zhu Ye , Strand Dee
Published: February 2020

Lithium ion battery electrolytes are complex formulations of solvents, salts, and additives. Each component can contribute to the battery performance in a unique way. For example, high dielectric constant solvents are necessary to dissolve the lithium salt, but are high viscosity. Therefore, low viscosity solvents are required to reduce the bulk electrolyte viscosity. Salt type and concentration can affect properties such as conductivity and thermal stability. Finally, many additives may be considered for use in formulations – with functions such as anode solid electrolyte interphase (SEI) formers, cathode SEI formers, acid scavengers, thermal stabilizers, and more. Development of optimized electrolyte formulations can require many experiments to find the best components and ratios/concentrations of components.

Using Wildcat’s high throughput battery workflow, we can apply combinatorial chemistry approaches to screen hundreds of new electrolyte components and study their interactions for electrolyte formulation development. Combining statistical models for formulation optimization, and component substitution, the function of a single component in a complex electrolyte and its interaction with other components can be elucidated. In this presentation, we will demonstrate the power of these tools to rapidly improve and optimize complex electrolyte formulations.
Improving the Performance of PEO-Based Electrolytes to Enable Metallic Li As an Anode
Authors: Gupta Arushi , Sakamoto Jeff
Published: February 2020

Replacing carbon-based anodes with metallic Li can drastically improve the performance of Li-ion batteries. However, stabilizing the Li metal/liquid electrolyte interface has been difficult and it is critical to replace them with solid state electrolytes. Solid polymer electrolytes (eg. PEO-LiTFSI) are of particular interest as they are easy to fabricate and have superior ductility, leading to suitable mechanical properties. This work addresses two challenges in developing viable PEO-based electrolytes – 1) factors affecting the SPE/Li interface are not well understood and 2) these electrolytes inherently have low room temperature conductivity.

The first part of this work focuses on minimizing the interfacial impedance between PEO-LiTFSI (SPE) and lithium anode by controlling the external variables in a Li/PEO-LiTFSI symmetric cell. The stability and kinetics of the interface were correlated with temperature, stack pressure and electrode type using electrochemical impedance spectroscopy (EIS) and dc cycling in order minimize interfacial impedance and maximize the limiting current (j
lim). Second, a critical stack pressure was established for 60oC and 80oC as 400 kPa and 200 kPa respectively by relating the stack pressure with interfacial impedance, below which interfacial impedance was shown to be at least 50 times higher. The effects of increasing temperature on the kinetics and mechanics of the interface manifest as variations in the EIS and cycling profiles. Lastly, the PEO-LiTFSI/Li interfacial impedance was reduced by 67%, from 4000 Ohms.cm2 to 1675 Ohm.cm2 at 30oC by using vapor deposited Li over Li foil electrode, increasing the limiting current from 0.5 mA/cm2 to 1mA/cm2.

The second part of this work was dedicated towards increasing the room temperature conductivity of PEO-LiTFSI electrolytes by adding a filler material. LLZO (Lithium Lanthanum Zirconium Oxide) was chosen because of its high room temperature conductivity and good cycling capabilities. Low values of interfacial impedance calculated from EIS on a trilamilar PEO-LiTFSI and LLZO cell with blocking electrodes proved the viability of the composite electrolyte. A solvent casting method was developed for the fabrication of flexible composite electrolytes of 100-500 microns thickness. The flexibility of the composite electrolytes was comparable to that of nascent PEO-LiTFSI electrolyte membranes, while their ionic conductivity was an order of magnitude higher. EIS was also used to determine the temperature dependence of the composite electrolyte’s conductivity. Lastly, the variation in bulk impedance with increasing LLZO volume percent in the PEO-LiTFSI was studied to optimize conductivity, while maintaining its flexibility.

Overall, this study provides effective guidelines for improving the performance of PEO-based electrolytes towards enabling viable all-solid state batteries.