bluuebunny/crossref_metadata_2025 huggingface dataset:
(Digital Presentation) Temporal Evolution of Kinetic Energy in Two Different Plasma Systems
Authors: Ostovarpour Farzaneh , Abbassi Shanbehbazari Mohammad Sadegh , Hajisharifi Kamal , Mehdian Hassan
Published: September 2023

During the last few decades, simulation has emerged as a powerful new tool. Numerous branches of science and engineering have been revolutionized by computer simulations. Through the use of particle-in-cell simulation systems comprising many species, including electrons, ions, neutrals, molecules, dust particles, etc., are studied by the plasma research community. The current work attempts to investigate the kinetic energy behavior in two various electrostatic plasma systems using a 1D PIC simulation. Two homogeneous and non-collisional systems are considered. In the first system, just cold electrons are present. Along with cold electrons, the second system also contains electrons with a thermal velocity of 0.4 ωpe/K . In other words, the second system includes two kinds of electrons (cold and warm electrons). The same initial perturbation is applied to both systems at t=0 s. Ions are assumed to be infinitely massive and only serve as a neutralizing background for electrons.

Diagrams of I, II, and III represent the kinetic energy of cold electrons, kinetic energy of electrons with a thermal velocity of 0.4 ωpe/K, and the total kinetic energy, respectively. It is worth noting that kinetic energy of cold electrons is equal to total kinetic energy in the first system. From the comparison of Figs. 1(a) and (b), it can be understood that when there is a cold type of electron in the system, the particles receive energy from the wave, but in a system that contains two types of cold and warms electrons, only warm electrons will receive energy from the wave and the kinetic energy of these warm particles increases. In contrast to Fig. 1(a), cold electrons give energy to the system. Additionally, in both cases, the total kinetic energy increases and as time goes on, the system approximates to stability and fluctuations decline. This result indicates that not only all the initial energy is not absorbed by the environment, but also a portion of it will remain in the medium.

Figure 1
Effect of Stress on the Electrochemical Response of Amorphous Silicon Electrodes
Authors: Le Anh Tuan , Ozanam François , Rosso Michel , Guin Laurent
Published: September 2023

Silicon electrodes for lithium-ion batteries exhibit a theoretical capacity ten times higher than that of the graphite electrodes currently used in commercial systems. When lithiated/delithiated, silicon experiences stresses on the order of one GPa, inducing the damage of the material, which results in poor cyclability. Concurrently, irreversible continuum thermodynamics predicts that these stresses affect the lithiation itself in different ways for monophasic and biphasic lithiation (progressive invasion of the electrode by a lithiated phase of given composition) [1,2]. When lithiation takes place homogeneously (without phase transformation), mechanical stresses affect lithiation through their effect on the chemical potential of diffusing lithium (Larché-Cahn theory). On the other hand, when lithiation is biphasic, mechanical stresses affect lithiation through an effect on both chemical potential of lithium and thermodynamic driving force acting on the phase boundary. This coupling has first been probed experimentally in homogeneous lithiation using a method where the stress state of silicon is modified indirectly through incremental delithiation [3].

In this work, we investigate the interplay between the electrochemical state (electrode potential and current density) of an amorphous silicon electrode and its stress state. The electrochemical response of the amorphous silicon thin film deposited on a stainless steel substrate has been recorded under varying mechanical loading during lithiation and delithiation cycles. The mechanical loading is applied by deforming elastically the steel substrate of the amorphous silicon thin film, which allows us to directly probe the contribution of mechanics to the lithiation/delithiation processes. When carried out under galvanostatic conditions, incremental changes in stress lead to instantaneous change in the electrode potential. Experimental results from uniaxial tensile tests show that an applied strain of 0.3%, resulting in changes in stress in silicon of ~ 200-300 MPa, induces a potential variation on the order of 2.5 mV. Stress-induced changes in the potential are measured for the biphasic first lithiation, as well as subsequent monophasic lithiation and delithiation sequences at different states of charge. These results are discussed within the context of continuum thermodynamic theories of the coupling between transport of chemical species and mechanical stress.

[1] A. F. Bower, E. Chason, P. R. Guduru, B. W. Sheldon, Acta Mater. 98 (2015) 229-241.

[2] A. F. Bower, P. R. Guduru, E. Chason, Int. J. Solids Struct. 69 (2015) 328-342.

[3] V. A. Sethuraman, V. Srinivasan, A. F. Bower, P. R. Guduru, J. Electrochem. Soc. 157 (2010) A1253.
Engineering Polymer-Assisted Self-Assembly Process for High-Capacity and Cycle-Stable Si-on-Graphite Anode of Li-Ion Batteries
Authors: Chang Shu Jui , Abdollahifar Mozaffar , Müller Jannes , Kwade Arno , Weng Yu-Ting , Wu Nae-Lih (Nick)
Published: September 2023

A facile and ready for scale-up process based on polymer-assisted solution self-assembly is developed for manufacturing high-capacity and cycle-stable silicon-on-graphite (Si@G) lithium-ion battery anode materials. The process involves first coating a polyelectrolyte poly(diallyldimethylammonium chloride, anchored by a cross-linked polyvinyl alcohol-glutaraldehyde matrix, onto micron-sized graphite particles using spray-drying. Process optimization succeeds in imparting the graphite particles with a permanent high positive zeta potential (>40 mV), which enables attracting Si nanoparticles (NPs) (zeta potential= -28.5 mV) uniformly and firmly onto the graphite surfaces in water. Collected by filtration, the resulting Si@G composite particles are finally subjected to a high-temperature (1000 oC) treatment in Ar to turn the polymer coating into a carbon layer, which engulfs the Si NPs. A Si@G composite powder containing nearly 7 wt.% Si and produced in a batch size of approximately 20 gram is demonstrated to have a high specific capacity of 605 mAh g-1, a remarkable cycle stability showing only 11% capacity loss after 300 cycles and notably high coulombic efficiencies comparable to those of a graphite electrode upon cycling. The designed polymer coating realizes charge-carrying graphite particle without damaging its surface structure and eventually leads to a surface carbon layer that prevents Si NP detachment, improves powder conductivity, and mitigates solid-electrolyte-interphase formation.
Electrophoretic Deposition of Chitosan as Synthetic SEI for Silicon Anode: A Model System Investigation
Authors: Yao Koffi Pierre , Mou Rownak Jahan , Barua Sattajit
Published: September 2023

The cycling performance of high-energy silicon (Si) based lithium-ion (Li-ion) battery is greatly hindered by the instability of the solid electrolyte interphase (SEI). Large volume change of Si during (de)-lithiation causes continuous cracking and re-formation of the SEI on the anode surface, eventually resulting in loss of Li inventory and extensive consumption of electrolyte. Our work aims to devise, ex situ, an artificial polymeric SEI that retains its integrity against the large volume expansion of Si (~300%) during lithiation, passivates the anode surface, and thus prolongs the cycling and calendar life of Si-based anodes. Electrophoretic deposition (EPD) was used to coat model silicon thin film surfaces with a layer of chitosan, an ionically conductive cationic polymer, with and without the addition of CH3COOLi in the precursor solution. Morphological study of the coated surface at nano and macroscale via AFM-nanoIR and SEM-EDX show CH3COOLi promotes conformal electrodeposition of chitosan. Electrochemical testing shows a boost in capacity retention and lower charge transfer resistance in the presence of the chitosan synthetic SEI. XPS and ATR-FTIR spectroscopy suggest that CH3COOLi caps the -NH2 group of the deposited chitosan via an amidation reaction which suppresses excess electroreduction of the cell electrolyte. Our work provides a pathway for controlling the chemistry and properties of the SEIs in batteries.
Solvent-Based Electrode Recovery for Direct Recycling of Li-Ion Batteries
Authors: Bai Yaocai , Yu Lu , Li Mengya , Jafta Charl , Essehli Rachid , Belharouak Ilias
Published: September 2023

The surging demand for Li-ion batteries (LIBs) in electric vehicles and consumer electronics drives the enormous expansion of cell manufacturing globally, resulting in a significant amount of manufacturing scraps and vast stockpiles of spent LIBs in near future. Recycling those waste LIBs and reintegrating the recovered materials into the battery supply chain are becoming critical to build a sustainable battery ecosystem. Cathode active materials (e.g., LiCoO2, NCA, NMC) and anode active materials (e.g., graphite) are tightly adhered to metal current collectors (Al and Cu) through organic binders (e.g., PVDF). Separation of those electrode materials from metal foils is challenging yet an enabling step for the direct recycling of LIBs. In this talk, a simple yet efficient solvent-based recovery process for delaminating electrode films from metal foils will be presented. Because of the absence of harsh chemicals, the recovered electrode films and metal foils are battery grade and free of damage in terms of physical and chemical properties. Additionally, reintroducing the recovered electrode materials into a new loop of cell manufacturing will be discussed. This environmentally friendly and cost-effective separation technique not only presents a closed-loop recycling approach but also greatly advances battery recycling into a new paradigm.
Three Dimensional Low-Tortuosity Carbon Fibers Enable High-Areal-Capacity and Long-Durability Battery
Authors: Liang Zhiming , Wang Yangyang , Liang Zhiming
Published: September 2023

Increasing the thickness of lithium-ion battery electrodes enables significant improvement in energy density and reducing the manufacturing cost. However, the existing barriers such as manufacturing challenges, performance issues, and scalability impede the development of fabricating thick electrodes. Here, we demonstrate a three dimension, low-tortuosity, and metal current collector free carbon fiber (CF) electrode which works as an integrated host substrate for LiNi0.5Mn0.3Co0.2O2 (NMC 532) cathode materials, similarly, the paired anode. The low tortuosity (~ 1.7) aligned microchannels of CF provide a good electron conductivity (~ 0.23 S cm-1), low Li+ diffusion resistance (~ 22 Ω), and high reversibility (91% over 500 cycles at C/3) compared to ~ 0.01 S cm-1, ~ 34 Ω, and 50% over 50 cycles for 100 µm slurry-casting graphite electrode with tortuosity of 2.9, respectively. The large porosity (~ 60%) enables CF a high mass loading capability of NMC 532 (> 70 mg cm-2) which provides a theoretical areal capacity ~ 14 mAh cm-2. The practical design of NMC 532/CF versus CF thick cells, with NMC 532 mass loading 32 mg cm-2, and theoretical areal capacity ~ 5.5 mAh cm-2 show an initial discharge areal capacity 4.1 mAh cm-2 at C/3 (1.5 mA cm-2), a capacity retention of 90.4% (500 cycles), 78.1% (1000 cycles), and 65.5% (1500 cycles). Furthermore, the post-analysis of long-term cycled NMC 532 particles, with consistent morphology of pristine particles, demonstrates lessen thermal stress across the electrodes. Our work presents a well-aligned microstructure for thick lithium-ion electrodes with practical level, scalable manufacturing, high areal capacity, and long-term electrochemical durability.
Dual Electrolyte Additives Enabling Bilayer SEI to Suppress Hydrogen Evolution Reaction in Aqueous Li-Ion Batteries
Authors: Lee Sukhyung , Kang Junsik , Lee Hochun
Published: September 2023

Aqueous Li-ion batteries (LIBs) feature safe operation, low cost, and environmental friendliness, but suffer from low energy density due to narrow electrochemical stability window (ESW) of aqueous electrolytes. While exploiting high-salt-concentration strategy of water-in-salt electrolytes (WiSEs) is effective in improving the electrochemical stability, the improvement is still insufficient to ensure practical feasibility of aqueous LIBs. In particular, the reduction stability of WiSEs needs further improvement to enable stable operation of low-voltage anode materials including Li4Ti5O12.

This talk reports that the co-use of two electrolyte additives can effectively expand the cathodic limit of various WiSE systems. The synergistic effect between the two additives is attributed to the formation of unique solid-electrolyte interphase composed of organic and inorganic bilayers. The inner inorganic layer suppresses hydrogen evolution reaction, while the outer hydrophobic organic polymer mitigates the dissolution of inner SEI. LiMn2O4/Li4Ti5O12 cells employing 21 m LiTFSI WISE with the dual additives exhibit excellent long-term cycling (>70% retention after 400 cycles at 25 oC) and good rate capability (110 mAh/g at 6 mA/cm2). The efficacy of the dual-additive approach is also demonstrated for other WiSE solutions including water-in-bisalt, hydrate melt, and aqueous/organic hybrid electrolytes, suggesting the general applicability of the dual-additive strategy.

Figure 1
Non-Fluorinated Diluent in Localized High Concentration Electrolytes Enabling Superior Performance of Lithium Metal Negative Electrode Battery
Authors: Moon Junyeob , Kim Dongok , Bekaert Lieven , Song Munsoo , Chung Jinkyu , Lee Danwon , Hubin Annick , Lim Jongwoo
Published: September 2023

Localized high-concentration electrolytes (LHCEs) are very promising strategies for the high-energy-density lithium (Li) metal batteries (LMBs). Nonsolvating diluents introduced in the LHCEs plays a critical role in physicochemical properties of LHCE and the overall LMB performance. However, there is a lack of design strategies for ideal nonsolvating diluents, and the reported cases are limited to fluorinated nonsolvating diluents (FNDs). FNDs suffer from accelerated decomposition at lithium metal, leading to electrolyte dry-up and ultimately battery failure. Furthermore, the high cost and potential environmental hazards of FNDs necessitate the development of non-fluorinated nonsolvating diluents (NFNDs). Here, we present a design rule for the ideal NFNDs by spectroscopically characterizing the Li+ solvation ability and miscibility. Our design rule identifies the ideal NFNDs, based on the superior cycling performane of candidate diluents over 350 cycles (99.0% ethoxybezene), 500 cycles (98.5% anisole), and 1400 cycles (99.0%, furan). NMR spectra revealed that the designed NFNDs were highly stable in electrolytes during extended cycles. Raman spectroscopy and theoretical calculation reveal that resonance of an electron pair on the oxygen atom of NFND molecules decreases the lithium-ion solvation ability, thereby achieving desirable non-solvating characteristics while maintaining good miscibility, superior cathodic stability, and low prices.

Figure 1
(Invited) Modeling of the Bulk and Electrical Double-Layer Structures of Localized High-Concentration Electrolytes
Authors: Wu Qisheng , Efaw Corey M. , Li Bin , Qi Yue
Published: September 2023

A new class of electrolytes, localized high-concentration electrolytes (LHCE), have shown many benefits to high-capacity electrodes (lithium (Li)-metal, silicon, sodium, zinc, and potassium).[1] These electrolytes combine high-concentration electrolytes (HCE) with salt and solvent with low-viscosity diluents. The dilutes were added to increase ionic conductivity while the locally highly concentrated salt-solvent clusters will facilitate stable solid-electrolyte interphase (SEI) formation while preventing metallic-dendrite formation. For example, it was demonstrated that an LHCE based on lithium bis(fluorosulfonyl)imide (LiFSI) salt, Dimethoxyethane (DME) solvent, and tris(2,2,2-trifluoroethyl)orthoformate (TFEO) diluent (e.g., LiFSI-1.2DME-2TFEO by mol) forms inorganic-rich, monolithic SEI and shows excellent cycling performance for Li-metal batteries under practical conditions.[2] Here, the interactions among cations, anions, solvent molecules, and diluent molecules create a complex design space, making the trial-and-error empirical approach less efficient.

Using density functional theory and classical molecular dynamics simulations, we reveal several important design principles:

a) The dielectric constant of the pure solvent or diluent is not a good descriptor to describe the solubility of the salt in solvent and diluent.

b) The single ion–solvent (diluent) binding energy is insufficient to predict the solubility, which also depends on the molecular structures and the corresponding solvation shell structure.

c) The salt-solvent, salt-diluent, and diluent-solvent solubilities jointly determine the solvation structures in LHCE. For example, at certain concentrations, the Li+ solvation shells contain both anions and solvent molecules with minimal participation of the diluent molecules. The local salt concentration can be even higher than its counterpart in the HCE. These simulated solvation structures in bulk electrolytes compare well with Raman spectrum and SAXS data.

d) Moreover, the solvation structures are temperature-sensitive. We revealed why the local salt concentration is higher at a certain temperature by MD simulations, which is further validated through Raman deconvolution analyses.

e) The SEI formation is sensitive to the electrolyte structure near a charged surface. Therefore, the electrical double-layer (EDL) structure of LHCE needs to be resolved. Here we give a statistical representation of the LHCE in the EDL and show how it differs from the bulk structure and its impact on SEI formation.

Reference:

[1] J. Electrochem. Soc., 2021, 168, 010522

[2] Nat. Energy 2019, 4, 796-805
Concentrated Electrolyte for Stable Lithium Metal Anode
Authors: Yan Shuo , Houache Mohamed , Yim Chae-Ho , Merati Ali , Baranova Elena A. , Weck Arnaud , Abu-Lebdeh Yaser
Published: September 2023

Secondary lithium-ion batteries have been widely used as energy storage systems for portable electronics and electric vehicles. Instead of applying graphite as the anode, lithium (Li) metal has an ultrahigh theoretical capacity (3860 mAh/g) that could significantly increase battery’s energy density. Li dendrite formation is considered the main issue when using Li-metal anodes. Therefore, anode-free batteries are suggested as a solution to this obstacle. However, the major problem with anode-free batteries is their inferior cycling performance than reported lithium metal batteries, resulting from the formation of a fragile and fractured Solid-Electrolyte Interphase (SEI).

To establish a robust SEI, novel lithium bis(trifluoromethylsulphonyl)imide (LiTFSI) and LiNO3-based electrolytes with four different ratios were prepared in the co-solvent system (1,3-dioxolane and 1,2-dimethoxyethane). Compared to the other three electrolytes, concentrated electrolyte (4M LiTFSI + 2 wt.% LiNO3 or 4+2) in Li||LiFePO4 cells indicated the highest initial discharge capacity of 154 mAh/g with a capacity retention of 78% after 50 cycles. Scanning electron microscopy was conducted to investigate the SEI morphology after the initial charge/discharge process. The deposited Li on the Li metal was highly dense, and no spiky or needle-like Li clusters were detected. Additionally, electrochemical impedance spectroscopy of the cells was measured after 1, 3, 5, and 10 cycles, respectively. The cells with 4+2 showed the smallest SEI resistance after different cycles, corresponding to a stable and less-resistive SEI formation.
An Experimental Correlation of Degradation with Cell Reversible and Irreversible Expansion Measurement in Pouch Cells
Authors: Pannala Sravan , Olide Everardo , Mollah Rafid , Jones Matthew , Efimoff Erin , Garrick Taylor R. , Dix Sean T. , Miao Yong , Stefanopoulou Anna , Siegel Jason
Published: September 2023

Lithium-ion batteries are used widely in portable devices and play an increasingly significant role in transportation and grid storage. These batteries degrade when they undergo charging and discharging and also when they are stored (calendar aging). The rate of this degradation depends on how the batteries are used and under what conditions. As the battery is cycled, its internal impedance and individual electrode capacities change, causing a change in its electrical performance. In addition, changes in the reversible and irreversible expansion of the cell are also observed. Of particular concern for pack design is the continued growth of irreversible battery thickness, thus affecting the stresses in the battery pack which is typically constrained to occupy a fixed volume. Understanding these dimensional changes will play an important role in accommodating this expansion over life for pack design.

Due to the aforementioned dimensional changes, the stresses that the battery faces at the beginning of life are different from the stress at the end of life when battery expansion is constrained due to packaging. To understand the impact of external stress/pressure on battery aging, we have designed a specialized spring loaded fixture which allows for operating the battery under relatively constant pressure, over the entire cell life, while simultaneously measuring the cell expansion. Battery thickness changes were measured for 82 identical pouch cells fabricated at the UofM Battery Laboratory using Targray NMC 622 Single Crystal cathode powder and Superior SLC 1520-T anode powder. The cells were loaded into the fixtures with 4 different initial pressures of 5 psi (standard beginning of life pressure), 15 psi, 25 psi (expected end of life pressure) and without any applied pressure. A baseline cycling protocol was established which included a modest amount of fast charging and cells were divided into three different thermal chambers to simulate the impacts of environmental temperature (room 25C, cold 0C, and hot 45C). Finally the impact of depth of discharge was also included in the test matrix. Three cells were assigned to each test condition to account for cell to cell variability. Instrumenting all the cells with laboratory grade LVDT expansion sensors would be prohibitively expensive [1]. To overcome the issue we used low-cost Inductive Displacement Sensors which provide inexpensive and high-resolution measurements of battery expansion under various load conditions. Further details on the sensor design and implementation are given in [2].

References:

[1] Mohtat et al, J. Electrochem. Soc. 168, 100520 (2021)

[2] Pannala et al, IFAC-PapersOnLine, 55(37), 712-717 (2022).

Figure 1
A Novel Framework for Consequence Prediction of Battery Thermal Runaway Failure Hazards
Authors: Thomas James Chris , Kunz Cythia , Fondren Max , Mathieu Olivier , Petersen Eric
Published: September 2023

Lithium-ion batteries (LIBs) are widely utilized for energy storage in a broad range of applications, such as handheld electronics, emobility, spaceflight vehicles, etc. Thermal runaway (TR) and subsequent combustion of LIBs represent several significant hazards to consumers, including substantial energy release, jet flames, toxic gases, airborne particulates, and secondary explosions. Numerous experimental investigations in the literature have measured the energy release and chemical composition of off-gasses during LIB TR, but little theoretical work has been completed to this end. The current study focuses on prediction of product chemical composition, flame temperature, and energy release for LIBs undergoing TR failure through implementation of chemical equilibrium analyses (CEA). Theoretical calculations for various LIB electrolyte decomposition and combustion scenarios were compared to data available in the literature. Excellent agreement was observed between predicted and experimental measured heats of combustion for plain LIB electrolytes, indicating the global thermodynamic properties are well captured by the modeling approach. Theoretical product gas production (i.e., moles of gas per mole of electrolyte) and composition were compared to experimentally measured values from accelerated rate calorimetry experiments. The results indicate that general trends are well captured by the CEA modeling approach developed here and that the standard experimental protocols documented within the literature can be improved. Similar theoretical predictions for battery failure experiments (product gas composition and energy release) are also presented. The novel modeling framework presented here can be used in future work to evaluate LIB failure hazards for existing systems and to evaluate the safety of future designs. In addition, this modeling approach provides unique insight into how adjusting global battery chemistry (cathode, electrolyte, etc.) changes the potential hazards produced battery thermal runaway and failure.

Figure 1
Holey Graphene/Sulfur Composite Cathodes Via Coupling with Ferroelectric Nanoparticles for Sustainable and High-Capacity Lithium-Sulfur Batteries
Authors: Zuluaga Gomez Claudia C. , Plaza Christian O. , Tripathi Balram , Katiyar Rajesh K. , Morell Gerardo , Lin Yi , Correa Margarita , Katiyar Ram S.
Published: September 2023

Lithium-Sulfur (Li-S) batteries have been considered promising for high energy density batteries to be used in electronic devices, electric vehicles (EV) and aircrafts which are becoming more prevalent. In addition, Li-S batteries have high theoretical capacity of 1,675 mAh/g in comparison to LIBs of 300 mAh/g. Although Li-S batteries are in great demand, their development is still plagued by rapid capacity fading mainly stemming from polysulfide shuttle. To improve the electrochemical performance of the cathode in Li-S batteries, holey graphene (hG) and carbon-based materials are employed. Holey graphene (HG) contains conductive skeletons as electron transfer paths and abundant mesoporous for longitudinal transport of ions. This architecture ensures efficient charge delivery throughout a thick electrode and maximizes electrode utilization, achieving high-rate and high-capacity energy storage. The coupling of a highly polarized ferroelectric nanoparticles materials (FNPs) layer is an approach that can be used to reduce the characteristic polysulfide shuttling in Li-S batteries. This coupling helps to build up an internal electric field and induces macroscopic charge separations on the surface of the cathode of Li-S batteries. The dry compression manufacturing process facilitates bonding between Sulfur and ferroelectric nanoparticles to generate a more stable cathode. In the present report we are presenting preliminary results of cathode having composition S47.5(FNPs)5hG47.5 in terms of structure, surface morphology and electrochemical performance. A reversible capacity of ~1,400 mAh/gs has been achieved with high coulombic efficiencies (> 87%) and low-capacity fading rate of 0.016% per cycle upto 60 cycles. The active sulfur mass loading ranging from 5.72 mgs/cm2 to 7.01 mgs/cm2 allows maximum high areal capacity up to ~10 mAh/cm2 and superior rate capability for 0.2mA/cm2 and 0.5 mA/cm2. These results suggest sustainable and high-yielding Li–S batteries can be obtained for potential commercial applications.
Surface Design Engineering of LiTaO3 Coating on Li-Excess Li2NiO2 Cathode Additive for Lithium-Ion Batteries
Authors: Byeon Yun Seong , Lee Hyo Bin , Park Min-Sik
Published: September 2023

The latest research has mainly focused on enhancement in the energy density of lithium-ion batteries (LIBs) to satisfy the rigorous industrial demands. As the most common approach for improving the energy density of LIBs, the utilization of high capacity anode materials, such as silicon suboxide (SiOx), has been highlighted, instead of graphite. SiOx anodes are known to have a high specific capacity and low operating voltage (< 0.5 V vs. Li/Li+). However, the severe initial capacity loss induced by the formation of solid electrolyte interphase (SEI) limits their commercial use in LIBs. To compensate for the initial loss of available Li+, the application of Li-excess cathode additives has been considered as the most practical strategy for supplying surplus Li+ during the initial charge process. In this respect, Li2NiO2 is a suitable cathode additive because it offers a high initial charge capacity (≥ 320 mAh g-1) and a compatible operating voltage with commercial cathode materials. Surface protection of Li2NiO2 is still required, however, due to its vulnerability to moisture (H2O) and carbon dioxide (CO2) in the ambient atmosphere. Moreover, Li2NiO2 becomes more structurally unstable during cycle due to oxygen (O2) gas evolution, leading to the formation of microcracks. To overcome these obstacles, we suggest a functional LiTaO3 coating layer onto the surface of Li2NiO2 for structural stabilization. In practice, the LiTaO3 coating layer can effectively suppress the production of impurities (i.e., LiOH and Li2CO3) at the surface of Li2NiO2 after air exposure. Furthermore, the gas evolution and microcracks can be minimized by enhancing the structural stability of Li2NiO2 during cycling. These synergetic effects of the LiTaO3 coating layer can provide clear insights for the development of Li-excess cathode additives for achieving advanced LIBs.
Lithium Sulfide –Carbon Composite Use as Positive Electrode in Post Lithium Ion Batteries Technology
Authors: Caban Huertas Zahilia , Zarrabeitia Maider , Varzi Alberto , Passerini Stefano
Published: September 2023

Li‐ion batteries (LIBs) are the powerhouse for the electronic devices in this modern mobile society, and enabler of the current communication revolution. Consumers demands advanced electronics and sustainable industries in general. To satisfy these demands, the new generation of rechargeable batteries need to provide much higher energy and power density than the actual technology. Commercial LIBs consist of lithium cobalt oxide as positive electrodes and graphite as a negative electrode, this system has energy density values ca. 250 WhL-1.

Lithium-sulfur is commonly considered as one of the most promising chemistries for improve traditional lithium-ion batteries in weight sensitive applications due to high theoretical capacity of lithium sulfide (Li2S) and high gravimetric energy density of such cells. Li2S provides a promising route for lithium storage due to high theoretical specific capacity (1166 mAh g−1). This positive electrode material can be coupled with lithium-free negative electrode to develop high-energy-density batteries; this can improve the safety of the devices. Li2S is significantly more thermally stable, and offer greater mechanical stability as no further volumetric expansion occurs upon cycling.

Li2S particles must be handled only in inert atmospheres (making production of high-performance cathode materials, on a commercial scale, quite difficult) and suffer from rapid degradation in cells during cycling. There are still challenges with it (e.g., low conductivity, high over potential and irreversible polysulfide diffusion), which have prevented the S utilization and stability. The dissolved polysulfides deposit on the surface of both electrodes resulting in a rapid impedance growth, loss in active material and ultimately battery failure.

The complex synthesis method of Li2S–carbon composites restrains the large-scale productivity. We propose an easy and time saving method to synthesize a Li2S based nanocomposite cathode material by wet milling.

This work may shed fresh insight into bridging the huge gap between high energy and safety of rechargeable cells for feasible applications.

Figure 1
Polymer Protective Layer Releasing Additives to Electrolyte of Lithium Metal Anode
Authors: Kim Yeona , Kim Ji-Wan , Oh Myung-Keun , Kim Dong-Won
Published: September 2023

As the need of batteries with high energy density raises, lithium metal anode has attracted considerable attention due to its high theoretical specific capacity and low reduction potential. However, there are several technical issues in practical use of lithium metal anode due to the growth of lithium dendrite and chemical instability with liquid electrolyte. It is essential to form the stable solid electrolyte interphase (SEI) layer on lithium metal anode to prevent lithium dendrite growth and minimize side reaction of liquid electrolyte. Designing the SEI with high Li+ ion conductivity and mechanical strength is imperative to stabilize lithium metal anode. Recently, various additives have been investigated to form a stable SEI layer on Li metal. However, during repetitive charge and discharge process, the additives in the electrolyte can be depleted by continuously forming SEI, which results in capacity fading of batteries. In this work, we developed the polymer protection layer containing excessive amount of additives that form the stable SEI layer. The additives can be stored in the polymeric layer, continuously released to the electrolyte during the repeated cycling. Electrochemical analyses such as linear sweep voltammetry and cyclic voltammetry were investigated, and the Li/Li symmetric cells showed the regulation of lithium deposition with small overpotential. The cycling performance of lithium metal batteries with protection layer was evaluated with high nickel NCM cathode.
Scalable Aqueous Battery Electrode Processing Strategy to Improve High C-Rate Capability of Lithium-Ion Battery Electrodes
Authors: Kim Doyoub , Magasinski Alexandre , Hunady Kyle , Sriram Ritvik , Krishnan Abiram , Raman Ashwin Sankara , Jakhar Rishika , Wang Fujia , Alamgir Faisal M. , Yushin Gleb
Published: September 2023

N-methyl-2-pyrrolidone (NMP) is a popular solvent in the battery industry, but its environmental impact has caused a shift towards aqueous-based slurry compositions. However, its use is limited in several nations due to its hazardous effects on humans and the environment. Developing environmentally friendly aqueous processing for electrode manufacturing is crucial as a countermeasure. To implement green and sustainable production method, a water-based battery electrode processing is devised to replace NMP, the standard organic solvent. In addition, the manufacturing procedures of lithium-ion battery electrodes must be tuned for the electrodes to provide equivalent performance to those produced by conventional processing.

In this study, we developed a simple aqueous battery electrode manufacturing method to form channels to reduce tortuosity and kinetic limitation of thick, high mass loading LIB battery electrodes and, more importantly, to improve rate performance at high C-rate while ensuring scalability and lowering electrode manufacturing cost
Addressing the Stability Challenges of Gas Diffusion Electrodes in the Presence of ILs-Based Solutions for the Continuous Electrochemical Reduction of CO2
Authors: Zammillo Federica , Guzmán Hilmar , Candela Danilo , Iliev Boyan , Narbey Stephanie , Hernández Simelys
Published: September 2023

Nowadays, it has become clear that the ever-increasing concentration of carbon dioxide (CO2) in the atmosphere is a threat to global security1. Therefore, the adverse climate events remind us that a transition towards a carbon neutral economy is more necessary than ever. Several approaches have been proposed to convert CO2 to valuable products and, among these, the electrochemical reduction of CO2 (ECR-CO2) represents one of the most promising alternatives. Herein, the ECR-CO2 has been carried out for the first-time employing silver based-gas diffusion electrodes (GDEs) within a continuous flow cell and in the presence of ionic liquids (ILs)-based solutions, which have been known to boost CO2-derived products2. As reported in the literature, the instability of GDEs is initiated by the high overpotentials needed during the CO2 reduction reactions and usually culminates in flooding3. This eventually has a negative impact on the product selectivity as well as limits the perspectives of scalability. In particular, in this work, different stability issues have been faced and visualized, for example, in the blackening of typical carbon-based gas diffusion layers (GDLs) and in the degradation/colour changes of ILs-electrolyte. Interestingly, by switching to non-carbon based GDLs it has been possible to reach and maintain a steady-state production of carbon monoxide (CO) both at -10 mA cm-2 and at -20 mA cm-2 for at least 40 minutes, with a H2/CO ratio slightly above 2 in the former case. Field Emission Scanning Electron Microscopy (FESEM) and Electrochemical Impedance Spectroscopy (EIS) techniques have been employed to carry out the physicochemical characterization of the electrodes and to assess the electrochemical interfaces within the system, respectively. The observed findings definitely encourage us to proceeding with our study on GDL-supported catalyst for the continuous ECR-CO2 in the presence of ILs solutions and offers openings for a large-scale deployment.

Acknowledgments

The financial support of the SUNCOCHEM project (Grant Agreement No 862192) of the European Union’s Horizon 2020 Research and Innovation Action programme is acknowledged.

References

IEA. Global Energy Review: CO2 Emissions in 2021. (2021).

Kunene, T., Atifi, A. & Rosenthal, J. Selective CO2 Reduction over Rose’s Metal in the Presence of an Imidazolium Ionic Liquid Electrolyte. ACS Appl. Energy Mater.
3, 4193–4200 (2020).

Yang, K., Kas, R., Smith, W. A. & Burdyny, T. Role of the Carbon-Based Gas Diffusion Layer on Flooding in a Gas Diffusion Electrode Cell for Electrochemical CO2 Reduction. ACS Energy Lett.
6, 33–40 (2021).
Ag-Based Gas Diffusion Electrodes for the Electrochemical CO2 Reduction by Pulsed Hydrogen Bubble Templation
Authors: Hoffmann Hendrik , Kutter Maximilian , Roth Christina
Published: September 2023

Energy-conversion technologies like the electrocatalytic nitrogen reduction reaction (N2RR), carbon monoxide reduction reaction (CORR) and in particular the electrochemical carbon dioxide reduction reaction (CO2RR) can contribute decisively to overcome the challenge of reducing greenhouse gas emissions. By reducing CO2 electrochemically, the carbon-cycle can be closed and industrially desired chemicals like syngas (CO + H2), formic and acetic acid, or hydrocarbons, such as methanol and ethylene, can be produced fossil-fuel free, depending on the catalyst material applied. Ag-based catalysts are very promising in the field of CO2RR, since they show high selectivities towards the reduction of CO2 to CO and current efficiencies of up to 100 %. In aqueous-fed systems, a significant drawback is the limited CO2 solubility, resulting in long diffusion pathways of CO2 within the bulk electrolyte 1, 2. Consequently, industrial conditions cannot be reached for CO2 electrolysis in aqueous solution in H-cell configurations due to the CO2 depletion within the porous electrodes that limit lab scale testing of CO2RR to current densities of approx. 35 mAcm-². One way to achieve commercially relevant current densities (> 200 mAcm-²) is the utilization of gas diffusion electrodes (GDEs) in flow cell configuration. These enable a decrease in CO2 diffusion lengths to approx. 50 nm, enhancing the mass transport to the catalyst 3.

In our contribution, we will demonstrate a facile and fast production process of Ag-based GDEs by combining pulsed electrochemical deposition of the Ag catalyst with ionomer infiltration of the electrode. Using the dynamic hydrogen bubble templation method (DHBT), we utilized the parasitic hydrogen evolution reaction (HER) to aid in a solvent free structuring of the 3D catalyst network. In this work, we focused on the deposition parameters by varying different pulse-to-pause ratios in order to increase the amount of deposited catalyst and thus, successfully reduced the overpotential during CO2RR operation (Fig. 1, left). To inhibit electrode flooding and decrease CO2 mass transport limitations during CO2RR, we infiltrated the electrode with a perfluorinated ionomer. SEM and EDS analyses showed a uniform Ag/F distribution along the cross section of the electrodes (Fig. 1, right), which resulted in the conversion of CO2 to CO at industrially viable current densities.

References

S. Hernandez-Aldave and E. Andreoli, Catalysts,
10(6), 713 (2020).

Z. Sun, T. Ma, H. Tao, Q. Fan and B. Han, Chem,
3(4), 560–587 (2017).

T. Burdyny and W. A. Smith, Energy Environ. Sci.,
12(5), 1442–1453 (2019).

Figure 1
Electrochemical CO2 Reduction Using a Free-Standing Porous Cu Framework as Catalyst
Authors: Zullufi Kosovare , Kurniawan Mario , Stich Michael , Bund Andreas
Published: September 2023

Due to fossil fuel combustion, the CO2 concentration in the atmosphere has reached around 410 ppm, causing major climate change on our planet. It thus becomes increasingly important to limit CO2 emissions or even remove CO2 from our atmosphere. One promising pathway to transform CO2 into useful chemicals is electrochemical reduction. However, electrochemical CO2 reduction is a challenging process that requires robust, low cost and stable catalysts. Copper is a promising candidate, at which CO2 can be reduced to several types of hydrocarbons.

In this contribution, CO2 reduction was performed with a free-standing porous copper catalyst that was prepared using an inexpensive hydrogen assisted electroplating process [1]. The porous copper framework has good mechanical stability and a large internal surface area. Furthermore, it can easily be manufactured on a large scale. Due to its porous nature with tunable pore sizes this copper framework is at the same time gas diffusion layer and catalyst. A porous sample with a 10 cm2 geometric surface area was assembled in a custom-made electrochemical cell consisting of an open cell anode compartment, a closed compact cell for the cathode, separated by a cation-exchange membrane. CO2 mixed with water vapor is transported to the free-standing porous Cu in the closed compact cell for the CO2 reduction process. The electrochemical cell is connected to a gas chromatograph (GC) for further gas phase product analysis. The experiments were performed in the potential range between -0.3 V vs RHE and -1.7 V vs RHE in 0.5 M KHCO3 as the anolyte. GC measurements show a considerable amount of methane (CH4), ethylene (C2H4), ethane (C2H6), and propane (C3H8) which indicates a successful reduction reaction of the CO2 on the porous copper framework surface.

[1] M. Kurniawan, M. Stich, M. Marimon, M. Camargo, R. Peipmann, T. Hannappel, A. Bund: "Electrodeposition of cuprous oxide on a porous copper framework for an improved photoelectrochemical performance." J. Mater Sci. 56 (2021) 11866-11880
(Invited) Electrochemical Carbon Dioxide Reduction on Titanium Nitride Mxenes
Authors: Djire Abdoulaye
Published: September 2023

Carbon dioxide (CO2) is one of the leading causes of environmental issues, including global warming, with a major path of release being the burning of fossil fuels as energy sources. For this reason, the capture and reduction of CO2 to value-added chemicals and fuels via electrocatalysis is on the forefront of the 21st century grand challenges, but the technology is facing a severe low selectivity towards higher hydrocarbon products. Among the various catalysts explored for CO2reduction reaction (CO2RR), two-dimensional (2D) carbides and nitrides based on early transition metals are gaining much attention due to their unique properties including high surface area, high electronic conductivity, and tunable surface chemistries. Compared to carbide MXenes, nitrides have been less explored despite their superior properties. In this work, we leverage the high electronic conductivity of 2D titanium nitride MXenes to tune the selectivity of CO2RR towards higher hydrocarbon products. Specifically, we report on an oxygen-assisted molten salt fluoride etching method to produce large-lateral, few-to-single layer Ti4N3 and Ti2N nitride MXene flakes, and how varying the Ti:N ratio influences the activity and selectivity of CO2RR electrocatalysis. On these nitride MXenes, we observe carbon monoxide as the main product with high selectivity values. To take advantage of this key intermediate for C2+ products, we deposit single atom Cu particles on the surface of the MXene to foster dimerization. This approach led to the formation of higher order carbonaceous products. We found that the selectivity can be tuned by changing the applied current. We also utilize in-situ/operando spectroelectrochemical techniques, including Raman and Fourier-transform infrared (FTIR) spectroscopies, to elucidate the mechanism of product formation on these MXene materials. These findings will be of great interest to the scientific community and ultimately to the broad society as they report on an efficient catalyst design for transforming CO2 into value-added fuels and chemicals.
Atomically Dispersed Fe- Ni Dual Metal Site Catalysts for High-Efficiency CO2 Electroreduction at Industrial‐Level Current Densities
Authors: Qi Manman , Zeng Yachao , Zachman Michael J. , Wu Gang
Published: September 2023

Carbon-supported nitrogen-coordinated single-metal site catalysts (i.e., M−N−C, M: Fe, Co, or Ni) are active for the electrochemical CO2 reduction reaction (CO2RR) to CO. Further improving their intrinsic activity and selectivity by tuning their N−M bond structures and coordination is limited. Herein, we expand the coordination environments of M−N−C catalysts by designing dual-metal active sites. The Ni-Fe catalyst exhibited the most efficient CO2RR activity and promising stability compared to other combinations. Advanced structural characterization and theoretical prediction suggest that the most active N-coordinated dual-metal site configurations are 2N-bridged (Fe-Ni)N6, in which FeN4 and NiN4 moieties are shared with two N atoms. Two metals (i.e., Fe and Ni) in the dual-metal site likely generate a synergy to enable more optimal *COOH adsorption and *CO desorption than single-metal sites (FeN4 or NiN4) with improved intrinsic catalytic activity and selectivity.