bluuebunny/crossref_metadata_2025_split huggingface dataset:
Chemo-Mechanical Model for Internal Stress Impact on Lithium Dendrite Growth
Authors: Meyer Julia , Mukherjee Partha P. , Roberts Scott A. , Harrison Katharine 
Published: July 2021

Lithium-ion batteries have the potential for greater efficiency and lifetime than current commercial options; however, there are operation and safety concerns that must be addressed before expanding their applications. During operation lithium dendrites form due to plating on Li-electrolyte surface inhomogeneities, which leads to battery failure once the dendrite reaches the cathode and short-circuits the cell. Addition of mechanical stress due to both internal and external pressures has been observed to decrease the propensity for dendrite growth. However, this addition leads to other complications, including inhomogeneous transport through the separator caused by inhomogeneous contact of a rough Li surface. In this work, we present a mesoscale model of a lithium protrusion brought into contact with a typical porous separator. The model couples mechanical deformation in both the lithium and separator with the electrochemical response during the charging phase. The nature of the model allows these materials to be brought into full or partial contact; the latter creates an electrolyte-filled gap, which drastically changes the electrochemical behavior across the 3-dimensional contact interface. The effects of internal stress and various model properties on the reaction rate across the protrusion surface are explored; through this, the propensity of plating across the interface may be predicted. Specific properties studied include the protrusion shape, separator porosity and modulus, liquid electrolyte diffusivity, and applied current density. Phase maps of the conditions for which dendrite formation is encouraged or suppressed are created and may be used to inform battery manufacturing and material choices.
Supported by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.
Protected Calcium Anodes: Lessons from Native Interphases
Authors: Zavadil Kevin R , McClary Scott A , Long Daniel M , Hahn Nathan T , Kotula Paul G , Jungjohann Katherine L 
Published: July 2021

Reversible ambient temperature Ca electrodeposition has thus far been demonstrated in only a few electrolytes. Additional knowledge is required to translate these early successes to electrolytes capable of high coulombic efficiency and stability toward self discharge required for a practical Ca metal ion battery. Calcium borohydride in tetrahydrofuran is promising in both regards, representing an opportunity to develop electrolyte design principles to support a Ca metal anode, despite a low oxidation threshold and low ionicity. Where efficiency and stability are attributed to calcium hydride shown to form during deposition, no direct evidence for the presence of hydride within the interphase has been reported. In an effort to determine how the interphase functions for Ca cation transport, we have conducted compositional and structural mapping of this interphase using analytical transmission electron microscopy, including cryogenic methods. We demonstrate the interphase that forms on the dense Ca deposit is a discontinuous, only partially crystalline oxide that contains B species, not unlike the interphase reported to form in carbonate electrolytes containing the tetrafluoroborate anion at elevated temperature. In this presentation, we discuss how the interphase attributes vary as a function of Ca deposition conditions, including tuned bulk and interfacial speciation and explore ideas of enhancing Ca anode function.
This work was supported by the Joint Center for Energy Storage Research, an Energy Innovation Hub funded by the U.S. Department of Energy. Sandia National Laboratories is a multimission laboratory managed and operated by National Technology & Engineering Solutions of Sandia, LLC, a wholly owned subsidiary of Honeywell International Inc., for the U.S. Department of Energy’s National Nuclear Security Administration under contract DE-NA0003525.
Correlating Ion Jumps with Bond Covalency in Solid Electrolytes
Authors: Aleman Johana Dolores , Adelstein Nicole , Garcia Oskar Kenyatta 
Published: July 2021

The development of Li-ion solid electrolyte batteries will improve battery safety and potentially energy density compared to conventional Li-ion batteries, which have liquid-electrolytes. Solid electrolytes are inorganic polycrystals, so they cannot catch on fire and resist dendrite growth. However, Li-ion conductivity in the solid-electrolyte is relatively slow compared to liquids, so this project focuses on understanding the diffusion mechanism of binary metal halides for the improvement of other superionic materials. This work is inspired by the high conductivity of α-AgI and is based on previous computational work by the Adelstein lab that showed thermally driven bond fluctuations aid in the conduction of Li-ions in Li3InBr6.
Since bond character is determined by the interaction of the cation and anion and crystal structure, we simulate both Ag and Cu metal halides in various crystal structures. Each crystal structure (α, β, zinc-blende, or rock-salt) is simulated at three temperatures for AgCl, AgBr, AgI, CuCl, CuBr, and CuI to obtain the activation energy barrier. Diffusivity, jump events, and bond character (ionic or polar-covalent) were calculated for each simulation, which allows us to differentiate between different diffusion mechanisms of Ag and Cu. Our on-going investigation into the silver and copper halides aims to test the hypothesis that fluctuations in bond character help superionic diffusion by correlating ion jumps with bond character.
Solving Lithium Dendrite Problems through Structure Design of Advanced Metal Anodes for Lithium Metal Batteries
Authors: Li Wentao , Zhou Yue , Zhang Liqun , Lucht Brett , Sun Xiao-Guang , He Wei , Chen Ke , Koggala Wellalage Dilni Kaveendi 
Published: July 2021

Commercial lithium ion batteries use mostly graphite as the anodes, which replaced the original lithium metal at the expense of energy density. Now the performance of graphite based lithium ion battery is approaching its theoretical limit, the holy grail of battery with lithium metal anode is increasingly needed for wider adoption of electric vehicles and renewable energy storage. However, dendrite growth during charge of the battery has been preventing its wide application in rechargeable batteries.
Solid electrolyte and lithium protection, such as polymers and ceramics, has traditionally been the solution for lithium metal anodes. Recently, there are also efforts to prepare 3D microporous electrodes, such as graphene, glass/carbon/copper fibers/scaffolds with or without infused lithium. While these efforts have had some successes in blocking lithium dendrite, lithium deposition still preferentially happens at the interface between the anode and the solid electrolyte/separator, and lithium dendrites can find its way through grain boundary or defects.
LiBAMA has proposed and developed a patent-pending 3D advanced metal anode (AMA) to solve the dendrite problem, by guiding the deposition of lithium instead of blocking the growth of the dendrite. The 3-D electrode’s surfaces directly adjacent to the separator are coated with an artificial passivation/SEI layer that redirects lithium deposition during charging to its interior, thus preventing dendrite formation at the interface. The concept was confirmed by computer simulation of current distribution in finite element analysis, showing uniform current distribution with the AMA, instead of high surface current density with regular 3D electrodes without the SEI. The designed anode has been prepared and evaluated in coin cells. Symmetrical cells with AMAs have completed 500 plating cycles at 8 mA/cm2 and 4 mAh/cm2 without shorting. LFP coin full cells with AMAs have shown 300 cycles with over 90% capacity retention. The technology solves the decades-old dendrite problems and will lead to lithium metal batteries with 500-600 Wh/kg energy density and 30% lower cost than graphite-based lithium ion batteries.

Figure 1
Iron-Based, Symmetric, Non-Aqueous Redox Flow Battery
Authors: Blesch Thomas , Moulin Cabral Diogo , Dong Shuo , Howlett Patrick C. , Macfarlane Douglas Robert 
Published: July 2021

The redox flow battery (RFB) is a promising technology for the long-duration storage of energy from domestic- to utility-scale. A RFB stores charge in a liquid electrolyte that is charged and discharged in an electrochemical cell reactor. Since storage and reaction site are separated, energy and power of the system can be scaled independently via electrolyte tank and cell stack dimensions. Iron as one of earth’s most abundant elements is an attractive active material, especially in symmetric RFBs using the same electrolyte on both negative and positive side of the battery. One way to realize such a system is by combining iron with redox-active ligands in non-aqueous solvents.[1],[2]

We study the iron tris(2,2’-bipyridine) complex which shows a metal-centred reversible oxidation and three ligand-based reductions that are solvent-dependent.[3] The influence of electrolyte composition on charge and discharge reactions as well as on viscosity and conductivity is further investigated. Charge-discharge cycling experiments are carried out in 3-electrode H-cell and flow cell setups. We determine failure modes for the positive side due to electrode kinetics and for the negative side due to solubility changes. We propose improvements to this non-aqueous RFB system based on the selection of electrode materials and cycling conditions.
[1] J. Mun et al., J. Electrochem. Soc.
2018, 165, 215-219.
[2] C. X. Cammack et al., DaltonTrans
.
2021, 50, 858.
[3] D. M. Cabral, P. C. Howlett, D. R. MacFarlane, Electrochim. Acta
2016, 220, 347-353.
Hydrazine Oxidation Electrocatalysis on Multi-Doped Carbons: Who Does What?
Authors: Eisenberg David 
Published: July 2021

Electrocatalysis of hydrazine oxidation, a promising carbon-free fuel, is both a practical goal, and a scientific paradox. Hydrazine is a common reductant in chemical synthesis, yet the onset potential for its electro-oxidation reaction is highly dependent on the catalytic surface. Some excellent catalysts have been developed in recent years towards this goal, designed for direct hydrazine fuel cells and for sensors. Most of these catalysts, however, are either prohibitively expensive (e.g. Pt-based ones), or easily deactivated (e.g Ni-based ones).
We have recently discovered a family of multi-doped carbons with excellent electrocatalytic activity towards hydrazine oxidation in alkaline pH.1,2 They contain many components, all of which were hypothesized as candidates for hydrazine oxidation active sites: from Mo-doped Fe3C nanoparticles, to single-atom metal sites, and to the N-doped, hierarchically porous carbon. They seemed to provide the first example of hydrazine oxidation on carbides. Moreover, they are stable, efficient, and easy to make on a large scale.
We then set out to understand the source of activity in these fascinating materials, and arrived at a range of surprising discoveries. First, we discovered how Mo-doping is actually unnecessary, and how Zn and Cu direct the nanostructure by different mechanisms.2 Then, we demonstrated that an N-doped carbon matrix – completely metal-free – is also highly active toward the reaction.3 At this point, we raised even larger questions: are the carbide nanoparticles even participate in the reaction? What does it really take for a carbon material to electro-oxidize hydrazine? To answer these questions, we combined electrochemical measurements, broad scope material characterization, and mechanistic quantum-mechanical calculations.4

In this talk I will present unpublished and recently published results, clearing the field of hydrazine oxidation on doped carbons, and explaining the individual catalytic, cooperative and structural roles of each component. While much remains to be understood about the activity and selectivity of these elusively simple material, and their excellent performance makes this challenge both technologically and scientifically appealing.
(1) Ojha, K.; Farber, E. M.; Burshtein, T. Y.; Eisenberg, D. Angew. Chem. Int. Ed.
2018, 57, 17168.
(2) Burshtein, T. Y.; Farber, E. M.; Ojha, K.; Eisenberg, D. J. Mater. Chem. A
2019, 7, 23854.
(3) Farber, E. M.; Ojha, K.; Burshtein, T.; Eisenberg, D., J. Electrochem. Soc. 2020, 157, 064517.
(4) Burshtein, T.; Tamakuwala, K.; Sananis, M.; Ioffe, K.; Hirsch, S.; Farber, E. M.; Grinberg, I.; Eisenberg, D., under preparation.
Reduced Electrocatalyst Loading on Vertical Graphene for Lithium Sulfur Batteries
Authors: Li Wenyue , Fan Zhaoyang , Li Shiqi , Bernussi Ayrton 
Published: July 2021

Lithium–sulfur batteries (LSBs) represent a promising energy conversion and storage technique for a multitude of applications, ranging from stationary grid storage to mobile electric vehicles and electronic devices. However, the dissolution of intermediate lithium polysulfides (LPSs) into the electrolyte causes the shuttle phenomenon of the soluble LiPSs and the subsequent adverse effects that result in low columbic efficiency and poor cycling stability, among other issues. Numerous methods have been investigated to attack the polysulfide shuttle effect, from physically blocking the diffusion of LPS to chemically immobilize the LPS to catalytic surface[1]. The later strategy is more effective in curbing the LPS diffusion and can also facilitate the LPS redox reaction by reducing their active energies. In this research, one of the promising catalytic materials, nickel cobalt sulfide (NiCo2S4, NCS) was investigated as catalyst to enhance the LSB performance by grafting it to vertical graphene (VG) grown on carbon nanofiber film (CNF) substrate. Different from other reported metal sulfides materials[2], the studied NCS nanosheets possess ultrathin and edge oriented structure, which is realized by the structural regulation function of VG. As a result, this NCS/VG material not only significantly reduces the utilization of NCS catalyst but also enormously improves the conductivity of the hybrid material. When using this free-standing film as catalytic overlayer on top of sulfur cathode, the derived LSB exhibited attractive electrochemical performances of 1000 mAh g-1 specific capacity at 0.3C and 800 mAh g-1 at 1C within 400 cycles for 2 mg cm-2 of sulfur loading and 850 mAh g-1 specific capacity at 0.25C for 6 mg cm-2 of sulfur loading. An areal capacity of 4.5 mAh cm-2 was demonstrated at the 100th cycle at 0.3 C.
[1] S. Li, Z. Fan, Encapsulation methods of sulfur particles for lithium-sulfur batteries: A review. Energy Storage Materials,
2020, 34, 107-127.
[2] M. Zhang, W. Chen, L. Xue, Y. Jiao, et al., Adsorption-Catalysis Design in the Lithium-Sulfur Battery. Adv. Energy Mater.,
2020, 10, 1903008.
Graphitic Mesoporous Carbon Thin Film Prepared By Rapid Thermal Annealing for Micro-Supercapacitors
Authors: Bhardwaj Ayush , Pagaduan James , Yu Yongguen , Einck Vince , Nuguri Sravya , Katsumata Reika , Watkins James 
Published: July 2021

The miniaturization of electronic devices led to the advent of on-chip power sources with high energy and power density requirement. The development of such miniaturized energy devices further requires the preparation and/or processing of thin films (down to a few nanometers) of active material. Mesoporous carbon possessing both high porosity and conductivity are desired for such applications. However, obtaining thin films of mesoporous carbon on various substrates using commercially viable approaches requires further improvement and investigation.
We have adapted rapid thermal annealing (RTA) as a novel approach to obtain mesoporous carbon. RTA enables rapid heating to temperatures up to 1200oC in just a few seconds and therefore provides a route for complete carbonization within a few minutes. Carbon precursor films comprised of brush block copolymers (BBCP) as sacrificial templates and phenol formaldehyde (PF) resin as a carbon source were prepared. In particular, the self-assembly of polydimethylsiloxane-b-polyethylene oxide (PDMS–b-PEO) BBCP and PF resin led to the formation of microphase-segregated film on various substrates including Si wafer, fused silica, and stainless steel. The PDMS domain in the BBCP fostered strong adhesion to the substrate even after annealing. RTA enabled complete carbonization of the precursor film within only 5 minutes, whereas conventional methods require approximately 500 minutes. Rapid processing at 1000oC resulted in the formation of mesoporous carbon with higher degree of graphitization, which is difficult to achieve with conventional carbonization method. The device prepared via RTA has a capacitance value of 7.0 mF/cm2 at 100mV/s, which is one of the highest values obtained for nanometer-thick carbon-based electrodes. These electrodes maintained a quasi-rectangular shape during the potential vs current scan, even at a scan rate of 20 V/s, which suggests that these materials are promising candidates for applications requiring very high-power density.
The mesoporous carbon structure having high porosity and high conductivity can be further utilized as supports for the deposition of pseudo-capacitance materials to further boost the energy density of the device.

Figure 1
Left Atrial Isolation and Appendage Occlusion in Patients With Atrial Fibrillation at End-Stage Left Atrial Fibrotic Disease
Authors: Zedda Angela , Huo Yan , Kronborg Mads , Ulbrich Stefan , Mayer Julia , Pu Liying , Richter Utz , Gaspar Thomas , Piorkowski Judith , Piorkowski Christopher 
Published: July 2021

Background:
Atrial fibrillation (AF) ablation in an end-stage left atrial (LA) fibrotic disease is more complex, has more recurrences, and may compromise transport function and stroke risk. We explored whether a total left atrial isolation procedure (TLAI) followed by left atrial appendage occlusion is a feasible treatment concept for rhythm and stroke risk control.

Methods:
Patients with symptomatic AF with extended LA fibrosis were enrolled consecutively for TLAI followed by left atrial appendage occlusion. At enrollment, all patients received a sinus rhythm LA voltage map. For TLAI, LA anterior and paraseptal ablation lines were placed, combined with right atrial and epicardial line completion and right pulmonary vein isolation as needed. Rhythm follow-up was provided through continuous monitoring using implantable cardiac devices.

Results:

Ninety-two patients (71±9 years, 41% male, 84% persistent AF, CHA
2
DS
2
-VASc 4) underwent 104 ablation procedures. Follow-up duration measured 48±22 months. At 12-month follow-up 70 out of 92 (76%) patients were free from any atrial arrhythmia recurrence, off antiarrhythmic drugs. All intended left atrial appendage occlusion procedures were successfully performed 6 to 8 weeks after TLAI. Combination of TLAI and left atrial appendage occlusion attenuated the native 4% annual stroke risk to <1% over the entire course of the study. Patients’ clinical AF and heart failure symptoms (European Heart Rhythm Association and New York Heart Association classification) significantly improved and remained stable during further follow-up. Invasive hemodynamic assessment as well as echocardiographic transport function analysis did not show evidence of detrimental hemodynamic effects of the treatment concept.

Conclusions:
This is the first report on a structured concept of interventional electrical LA isolation and LA appendage occlusion for rhythm and stroke risk control in patients with AF at an end-stage left atrial fibrotic disease. We report feasibility, safety, and efficacy of such a treatment approach.
Temporal Emotions and Historical Vulnerability: Music as a Vehicle of Ideology in Cold War and Peste Noire
Authors: D’Arcens Louise 
Published: July 2021

Abstract
This essay focuses on the Polish film Cold War and the oeuvre of the French nationalist black metal band Peste Noire, examining them as twenty-first-century texts that disclose music’s capacity to solicit emotion in the service of ideology. Despite their aesthetic and ideological differences, each text demonstrates the importance of temporal emotions – that is, emotions that register a heightened sense of the relationship between present, past and future. Each text portrays these emotions’ ideological significance when attached to ideas of a national past. Dwelling on Peste Noire’s racist-nationalist use of the medieval past, the essay explores music as a medium for emotional performances in which white people appear to convey vulnerability while actually reconfirming white supremacy. Peste Noire’s idiosyncratic performance of aggressive vulnerability is a temporal emotion that self-consciously lays claim to a long emotional tradition reaching back to the French Middle Ages.
Emotions, Activism and Documentary Storytelling: A Biographical Production-Based Case Study
Authors: Murray Tom 
Published: July 2021

Abstract
The biography of Douglas Grant (c.1885–1951) has been publicly and popularly told in media since 1916. Interestingly, Grant’s unusual life-story has consistently been deployed to serve various political agendas. This essay examines the role of popular-media biographies of Douglas Grant and the emotions embedded in them, and utilises a documentary-film production as a case study to examine relations between these emotions, activist agendas and documentary-film storytelling. Additionally, given the consistent use of tragedy as a formal narrative structure employed in tellings of Douglas Grant’s story, this essay also describes how narrative structures are not culturally neutral, but are themselves emotionally suggestive cultural productions. Analysing a century of tellings of the Douglas Grant biography, this essay also offers insights into how conquest-colonial ideology is manifest in these often ‘tragic’ tales. As an attempt at decolonising scholarship, this essay also responds to insights by Indigenous commentators within the case-study text to reflect on Indigenous ontologies and the role of Country and Indigenous futurism as places/sites/histories of hope.
Re-enactment and Traumatic Memory: Cinematic Ethics in The Act of Killing and S21: The Khmer Rouge Killing Machine
Authors: Sinnerbrink Robert 
Published: July 2021

Abstract
The Act of Killing (Oppenheimer, 2012) and its companion piece, The Look of Silence (2014), are powerful works of cinematic ethics. The former is a ‘perpetrator documentary’ that invites killers to make movie re-enactments of their crimes, the latter a case of ‘ethical witnessing’ in which a victim’s descendant questions his brother’s killer. In what follows, I explore The Act of Killing’s use of stylised re-enactments, using various movie genres as distancing and mediating devices, which enable the perpetrators to approach and expose their traumatic acts of violence. I contrast this with Rithy Panh’s perpetrator/witness documentary, S21: The Khmer Rouge Killing Machine (2003), focusing on the mass killings perpetrated by the Pol Pot regime (1975–1979), which uses both visual representations and a more direct, bodily performative mode of re-enactment, to represent and communicate traumatic memory. Both films examine a range of moral emotions, solicited through interview sequences and different modes of cinematic re-enactment. These strategies enable the perpetrators to expose their traumatic violence and, in some cases, acknowledge the suffering of their victims, but also allow the perpetrators to be questioned and held to account, staging an ethical encounter wherein the social recognition of traumatic memory of political violence might become possible.