bluuebunny/crossref_metadata_2025_split huggingface dataset:
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.
Gas Additives for Silicon Anode Lithium-Ion Batteries
Authors: Soto Mel , Weddle Peter J , Colclasure Andrew M. , Tremolet de Villers Bertrand J. , Fink Kae 
Published: September 2023

While many organic liquid and electrolyte salt formulations have been explored to improve the stability of lithium-ion batteries, less research has been done to determine the role of evolved gasses in the performance of commercial Li-ion battery chemistries, let alone novel combinations of gas additives that may affect the solid-electrolyte interphase (SEI) formation and evolution.[1,2] Many gases are generated during Li-ion battery cycling, any of which could have possible beneficial or harmful effects on performance. Currently, only the effect of carbon dioxide (CO2) gas addition to Li-ion batteries with Si anodes has been studied.[3-4] In addition to CO2, ethylene gas (C2H4) is a promising additive for Si anode systems because it is a precursor in polyethylene polymerization reactions, nCH2=CH2 --> [-CH2-CH2-]n. In addition, polyethylene oxide (PEO) has been observed in the Si-anode SEI and contributes to its passivation while maintaining flexibility.[5] Therefore, creating polyethylene and increasing PEO concentration in situ via ethylene gas doping may yield an improved SEI and more-stable battery.
This work investigates the potential of gas-phase additives, including CO2 and C2H4, to improve the performance of Si anodes for Li-ion batteries. The pressure decay of the gasses at different starting pressures dissolving in GenF3 electrolyte (1.2 M LiPF6 in 3:7 wt:wt ethylene carbonate to ethyl methyl carbonate + 3 wt% fluoroethylene carbonate) was monitored to determine the saturation concentration of dissolved gas. The experimental pressure decay curve was fit to a model and extrapolated to predict the final pressure at equilibrium.[6] The relationship between partial pressure and concentration of dissolved gas in GenF3 at equilibrium was plotted and a curve was drawn to determine the Henry’s law constant. Varying volumes of gas were injected into battery pouch cells containing Si nanoparticle anodes and LiFePO4 (LFP) cathodes to pressurize them to different pressures. Electrochemical cycling and subsequent multi-phase analyses, including vibrational spectroscopy and X-ray characterization of the SEI surface layer and GC-MS/FID were conducted to determine the impact of gas doping on the capacity, SEI, and gas phase reaction products.
References:
[1] G. G. Eshetu and E. Figgemeier, ChemSusChem,
12 (12), 2515-2539 (2019).
[2] L. Bläubaum, P. Röse, L. Schmidt, and U. Krewer, ChemSusChem,
14 (14), 2943-2951 (2021).
[3] L. J. Krause, V. L. Chevrier, L. D. Jensen, and T. Brandt, J. Electrochem. Soc.,
164 (12), A2527-A2533 (2017).
[4] E. J. Hopkins, S. Frisco, R. T. Pekarek, C. Stetson, Z. Huey, S. Harvey, X. Li, B. Key, C. Fang, G. Liu, G. Yang, G. Teeter, N. R. Neale, and G. M. Veith, J. Electrochem. Soc.,
168 (3), 030534 (2021).
[5] M. C. Schulze, G. M. Carroll, T. R. Martin, K. Sanchez-Rivera, F. Urias, and N. R. Neale, ACS Applied Energy Materials,
4 (2), 1628-1636 (2021).
[6] E. Behzadfar and S. G. Hatzikiriakos, Energy & Fuels,
28 (2), 1304-1311 (2014).
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
(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
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
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
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