bluuebunny/crossref_metadata_2025 huggingface dataset:
Probing the Entropy of Coal Derived Graphite for Battery Applications
Authors: Paul Abigail , Magee Regan , Wilczewski Warren , Wolfe Kody D , Wichert Nathan , Trembly Jason , Staser John A. , Garrick Taylor R.
Published: February 2024

The entropy coefficient (dV/dT) is one critical parameter to characterize for lithium intercalation materials in lithium-batteries for various applications. It can be utilized to determine the amount of reversible heat that is generated during operation, and can impact the system level design by driving changes in the battery management system and cooling strategy. In previous studies, we have quantified the entropy coefficient at the cell level for large format automotive cells. In this work, we focus on estimation of the entropy coefficient for anode active materials, and will probe differences in the entropy coefficient for graphite derived from coal when compared to commercially available graphite for battery anodes. The temperature impact and state-of-lithiation impact on the entropy coefficient will be further probed.

Commentary on the applicability of various thermodynamic representations and their ability to capture the entropy coefficient for typical electrochemical simulations and the extension to module and pack level thermal design requirements will be provided.
Carbon Patterned Layer for the Low-Temperature Performance of Lithium-Ion Batteries
Authors: Lim Jaejin , Park Siyoung , Kim Dohwan , Lim Jaejin
Published: February 2024

Lithium-ion batteries (LIBs) are widely used as an energy source as the electrification of industries, due to their high energy density, long lifespan, and excellent cost-effectiveness. However, if the LIBs operated in environments that are not at an appropriate temperature, the electrochemical performance of the LIBs can be rapidly reduced and leading to a significant deterioration in cycling characteristics.

In particular, at low-temperature environments, the diffusion, migration and charge transfer resistance can substantially increase. As a result, the capacity and rate capability of the lithium-ion battery are lower than that of the room temperature environments. To improve the performance of LIBs at the low-temperature, previous studies have been introduced a heat generation layer inside or outside batteries. However, adding a heat generation layer reduces the energy density of the system, and the layer inside the battery can act as an electrical resistance layer, leading to a decrease in performance at the room temperature.

In this research, a patterned carbon layer was introduced at the interface between the current collector and the electrode composite layer to improve the low-temperature characteristics of LIBs. The patterning of the carbon layer not only reduces the decrease in energy density but also does not significantly limit the electron transfer path between the current collector and the electrode composite layer.
(Invited) Effect of Temperature on Lithium-Ion Battery Voltage Response and How to Model It in the Mechanistic Modeling Approach
Authors: Dubarry Matthieu , Fernando Alexa
Published: February 2024

The ongoing usage of lithium-ion cells and packs in both stationary and mobile applications necessitates comprehensive tools and models to diagnose and prognose cell performance onboard. One of the main tasks of a battery management system is to infer the state of charge (SOC) and state of health (SOH) of batteries. SOC estimation is usually done by relating a measured relaxation voltage to a stored SOC versus open circuit voltage (OCV) curve. The latter is dependent on the cell SOH and its degradation path. Therefore, both an accurate OCV and relaxation measurement are necessary for state estimation and it is essential to consider how they vary with temperature to ensure accuracy.

This study aims at an exploration of the impact of temperature on relaxation and cell’s kinetics and how the voltage response at different temperatures can be simulated using the mechanistic modeling framework by tuning two parameters, the ohmic resistance increase and the rate degradation factor. The mechanistic modeling framework is using electrode half-cell data to synthesize the terminal voltage of battery cells based on the individual electrode potentials. Although proven valid in the quantification of degradation modes, path dependence of aging and cell-to-cell variations, the application of this modeling framework has been restricted so far mostly to voltage profiles recorded at room temperature and low rates. To be used in deployed battery management systems, this limitation should preferably be overcome to enable on-board diagnostics from medium to high rates and at any temperature.
Leveraging Molecular Dynamics to Improve Porous Electrode Theory Modeling Predictions of Lithium-Ion Battery Cells
Authors: Dix Sean T. , Lowe Jeffrey S. , Rashvand Avei Mehdi , Garrick Taylor R.
Published: February 2024

Lithium-ion battery cell modeling using physics-based approaches such as porous electrode theory is a powerful tool for battery design and analysis. Cell metrics such as resistance and thermal performance can be quickly calculated in a pseudo-two-dimensional (P2D) framework. For engineering of electric vehicle batteries, speed and fidelity of electrochemical models is paramount in a competitive landscape. Physics-based models allow for high fidelity but require detailed knowledge of the cell component material properties. Acquiring these material characteristics typically requires time-consuming and expensive experiments limiting the ability to quickly screen through cell designs. One approach to circumvent costly experiments is to use molecular dynamics to calculate electrolyte transport properties. We demonstrate how cell modeling using simulated transport properties enables predictions of cell level metrics, allowing for experiment-free component screening. We also show how the variation in transport property predictions from molecular dynamics affects the final cell level performance predictions.
(Battery Division Early Career Award Sponsored by Neware Technology Limited) Understanding Interfacial Mechanisms that Govern Performance in Solid-State Batteries
Authors: McDowell Matthew
Published: February 2024

Solid-state batteries offer the promise of improved energy density and safety compared to lithium-ion batteries. Here, I will present our emerging understanding of the key differences between how high-capacity anode materials behave in solid-state batteries compared to in conventional liquid-electrolyte batteries. The electro-chemo-mechanical evolution of materials at solid-solid electrochemical interfaces is different than at solid/liquid interfaces, and contact evolution in particular plays a critical role in determining the behavior of solid-state batteries. I will focus on mechanisms governing lithium metal anodes (including lithium in the “anode-free” configuration) and alloy anodes. Lithium metal anodes in solid-state batteries are intrinsically limited by void formation during stripping and dendrite growth during plating. Anode-free solid-state batteries, in which there is no initial lithium metal at the anode interface, offer extremely high energy density, but there is a lack of understanding of how their behavior differs from excess-lithium electrodes. Using X-ray tomography, cryo-FIB, and finite-element modeling, we show that anode-free solid-state batteries are intrinsically limited by current concentrations at the end of stripping due to localized lithium depletion. This causes accelerated short circuiting compared to lithium-excess cells. Based on these results, the beneficial influence of metal alloy interfacial layers on controlling lithium evolution and mitigating contact loss from localized lithium depletion, including at low stack pressures, will be discussed. X-ray tomography is further shown to be particularly useful in observing the dynamic evolution of lithium metal, including void formation and filament growth. The second part of the talk focuses on alloy anodes. Alloy anodes typically exhibit fast capacity decay in lithium-ion batteries because of excessive solid-electrolyte interphase growth. We show that alloy anodes in solid-state batteries can exhibit improved interfacial stability and enhanced cyclability. Furthermore, in situ measurement of stack pressure evolution during cycling shows that the volume changes of alloy anodes can lead to large pressure swings within the cell, giving insight into electrode composite evolution. Based on these insights, we present a new design for dense foil alloy anodes. This design offers a paradigm that does away with slurry coating, potentially reducing manufacturing costs. Taken together, these findings show the importance of controlling chemo-mechanics and interfaces in solid-state batteries for improved energy storage capabilities.
Investigations into a Perforated Reference Electrode Applied in Small Li-Ion Pouch Cells
Authors: Stehle Philipp , Rutz Daniel
Published: February 2024

The use of reference electrodes (REs) in lithium-ion batteries allows enhanced electrochemical analysis of individual electrodes via potential monitoring or electrochemical impedance spectroscopy (EIS). The design and material choice of REs is still under debate. An ideal RE should cover a large proportion of the electrode area in order to measure representative potentials, but also not block the pathway of the lithium ions significantly to avoid distorted measurements. Here, we show studies on an own-designed perforated RE (PRE) based on LiFePO4 applied in ≈60 mAh graphite/NMC811 pouch cells.[1]

In our setup shown below, more than 17% of the electrode area is covered and therefore monitored by the PRE, which is a more than fourfold increase compared to our previous work.[2] Despite this large cover proportion, only negligible capacity differences were observed for charge rates up to 2C compared to cells without PRE. At higher rates, the blocking effect caused by the PRE was still very low (7.3% reduced capacity compared to cells without PRE at 5C). Reproducible and plausible anode voltage curves were obtained for all C-rates and the beginning of Li plating at 3C was correctly detected (visually verified by cell teardown). Comparison tests showed that the PRE presence did not have significat influence on the cell EIS spectra. Except for one anode spectrum recorded at a state of charge of 0, the impedance spectra of the individual electrodes recorded by the PRE were confirmative and artifact-free. The results demonstrate that our PRE can be reliably applied for detailed electrochemical investigations of lab-scale electrode coatings in small pouch cell formats.

[1] P. Stehle, D. Rutz, A. M. Bazzoun, C. Seidl, I. Bauer, M. Anjass, Energy Technol. 2023, 2300278, DOI: 10.1002/ente.202300278.

[2] D. Rutz, F. Brauchle, P. Stehle, I. Bauer, T. Jacob, ChemElectroChem 2023, e202300216, DOI: 10.1002/celc.202300216.

Figure 1
Sputter Grown Hexagonal WSe2@Graphite Nanoflakes for Electrochemical Energy Storage
Authors: Tomar Akshay , Issar Sheetal , Adalati Ravikant , Chandra Ramesh
Published: February 2024

In the pursuit of sustainable and efficient energy storage solutions, researchers have continuously explored novel materials and technologies to enhance the performance of energy storage devices. Recently, transition metal dichalcogenide (TMDCs) such as molybdenum disulfide (MoS2), molybdenum diselenides (MoSe2), and tungsten disulfide (WS2) with a honeycomb-like structure has sparked considerable interest in utilization as electrode material for supercapacitor (SCs) applications due to their unique layered structures. Generally, the small surface area of TMDCs in their bulk form restricts their practical usage in the SCs applications. Whereas TMDC in thin 2D form exhibits high surface area and flexibility to the electrode material which allows more charge storage and results in high capacitance and energy density. In the present work, high-quality tungsten diselenide (WSe2) thin film electrodes were deposited over graphite sheets (WSe2@Graphite) using DC magnetron sputtering technique at an elevated temperature of around 200 0C under the controlled argon atmosphere. The electrochemical properties of these WSe2@Graphite electrode were investigated in three electrodes configuration using 1M Na2SO4 aqueous electrolyte by recording CV, GCD, and EIS spectra. The hexagonal WSe2@graphite nanoflakes were found to exhibit an exceptionally high areal capacitance of 88.05 mF/cm2 and energy density of 7.83 µWh/cm2 at a scan rate of 5 mV/s. Further, GCD was performed, and the WSe2@graphite electrode exhibits a high areal capacitance of 37.5 mF/cm2 at the current density of 0.5 mA/cm2. The WSe2 thin film electrode shows a high energy density of 3.3 µWh/cm2 at a power density of 199.98 µW/cm2. Additionally, the WSe2@graphite thin film electrode demonstrates high cyclic stability with retaining ~ 90.33% capacitance even after 2000 consecutive GCD cycles. The obtained hexagonal nanoflakes-like morphology provides a high surface area and porous structure that helps to improve the electrochemical performance of the WSe2 thin film. The obtained results demonstrate that the WSe2@graphite thin film exhibit excellent electrochemical performance and can be utilized as a potential material for supercapacitor electrodes.

Keywords- Transition metal dichalcogenide (TMDCs), tungsten diselenide (WSe2), DC magnetron sputtering, supercapacitor, and nanoflakes

Figure 1
New Low Cost Sulfide Electrolytes for All Solid State Batteries
Authors: Raj Hari , Neveu Audric , Pralong Valerie
Published: February 2024

The low cost, safe and high energy storage technology is needed to ensure a continuous energy supply from renewal energy sources. However, current Li-ion batteries (LiBs) are facing challenges to fulfil the safety and high energy and power demands of fast-growing market of electric vehicles (EVs). In particular, liquid organic electrolytes used in conventional LIBs have raised the safety issues due to serious fire risk. Solid state batteries (SSBs) are considered to provide better safety as compared to LIBs because of solid electrolytes (SEs) are used in SSBs instead of flammable organic liquid based electrolytes [1-4].

The various types of solid electrolytes have already been reported for SSBs which can be divided into oxides, sulfides, halides and polymers based on their properties, advantages and disadvantages [5]. Among these solid electrolytes, sulfide solid electrolytes have advantages over other due to high conductivity and ductile nature of sulfides [6]. The discovery of Li10GeP2S12 solid electrolyte called LGPS structured sulfide electrolyte have shown great potential to replace liquid electrolyte as ionic conductivity of LGPS was found 1.2×10-2 S cm-1 at room temperature comparable to the conductivity of organic liquid electrolyte [7]. However, Li10GeP2S12 electrolyte suffers with poor cyclability in solid state batteries due to reduction of Ge+4 ions to Ge0, and instable against lithium metal anode. Moreover, germanium (Ge) is a rare and expensive element, which limits the industrial application of Li10GeP2S12 [8, 9].

Therefore, in the present work, we have developed LGPS structured based new Ge free solid electrolytes with high conductivity and better electrochemical stability. The phase identification of newly synthesized solid electrolytes is done by X-ray diffractometer technique along with Rietveld refinement analysis. The conductivity of prepared solid electrolytes is determined by electrochemical impedance spectroscopy. The ionic conductivity of newly synthesised electrolytes has reached upto 0.67 mS cm-1 at room temperature. The electrochemical analysis of prepared solid electrolytes is done using Li-metal in both side (in symmetric cell) as well as using standard cathode and anode materials (full cell).

References:

Janek et al., Energy 1, 2016, 16141.

Xu et al., Joule 2, 2018, 1991.

Li et al., RSC Adv. 5, 2015, 52382.

Scrosati et al., Power Sources 195, 2010, 2419.

Zhang et al., Energy Storage Mater. 10, 2018, 139-159.

Jiang et al., ACS Appl Mater Interfaces 12, 2020, 54662-70.

Kamaya et al., Mater., 10, 2011, 682–686.

Neveu et al., Power Sources 467, 2020, 228250.

Wan et al., ACS Energy Lett., 6, 2021, 862–868.
Dithiolate-Based Scorpion Arm Ligand Synthesis and Characterization
Authors: Mazumder MD Motiur Rahaman , Islam Rejaul , Islam Rezoanul
Published: February 2024

Redox flow batteries (RFBs) play a vital role in the efficient and reliable utilization of renewable energy sources by providing a means to capture and store excess energy for later use.1–6 The synthesis and characterization of a novel scorpionate arm ligand, i-mntPy- (2,2-dicyano-1-pyridin-2-ylmethyl-1,1-dithiolate), are presented in this study. The ligand i-mntPy- was synthesized through a multistep synthetic route, starting from commercially available precursors. The chemical structure of the ligand was confirmed using various spectroscopic techniques, including NMR spectroscopy, ESI-MS, and Elemental analysis. Furthermore, the coordination ability of i-mntPy- to facilitate 2e- transfer in M(II/IV) coordination environment was investigated by the computational study and addition of Ni(II) and Pd(II) ions in the i-mntPy- solution. The results demonstrate the successful synthesis and characterization of the novel scorpionate arm ligand i-mntPy-, which coordinates with d8 metal centers and holds promise for future applications in coordination chemistry and energy storage.

References

(1) Mazumder, Md. M. R.; Jadhav, R. G.; Minteer, S. D. Phenyl Acrylate-Based Cross-Linked Anion Exchange Membranes for Non-Aqueous Redox Flow Batteries. ACS Mater. Au
2023. https://doi.org/10.1021/acsmaterialsau.3c00044.

(2) Rahaman Mazumder, M. M.; Islam, R.; Khan, M. A. R.; Anis‐Ul‐Haque, K. M.; Rahman, M. M. Efficient AcFc‐[Fe III (Acac) 3 ] Redox Couple for Non‐aqueous Redox Flow Battery at Low Temperature. Chem. – Asian J.
2023, 18 (1). https://doi.org/10.1002/asia.202201025.

(3) Mazumder, Md. M. R.; Dalpati, N.; Pokkuluri, P. R.; Farnum, B. H. Zinc-Catalyzed Two-Electron Nickel(IV/II) Redox Couple for Multi-Electron Storage in Redox Flow Batteries. Inorg. Chem.
2022, 61 (48), 19039–19048. https://doi.org/10.1021/acs.inorgchem.2c03124.

(4) Mazumder, Md. M. R.; Burton, A.; Richburg, C. S.; Saha, S.; Cronin, B.; Duin, E.; Farnum, B. H. Controlling One-Electron vs Two-Electron Pathways in the Multi-Electron Redox Cycle of Nickel Diethyldithiocarbamate. Inorg. Chem.
2021, acs.inorgchem.1c01699. https://doi.org/10.1021/acs.inorgchem.1c01699.

(5) MAZUMDER MDMOTIURRAHAMAN, Islam R. Temperature-dependent study of AcFc-FeIII(acac)3 redox couple for non-aqueous redox flow battery. ChemRxiv. Cambridge: Cambridge Open Engage; 2022; https://doi.org/10.26434/chemrxiv-2022-3177p

(6) Islam, R.; Mazumder, M. M. R.; Farnum, B. H. Solvent Dependent Spectroscopic and Electrochemical Studies of Nickel (II) Diethyldithiocarbamate for Energy Storage. ECS Meet. Abstr.
2021, MA2021-01 (1), 54–54. https://doi.org/10.1149/ma2021-01154mtgabs.

Figure 1
Impact of Short Chain Polymer in Ionic Conductivity for Polymer Solid-State Electrolyte Towards Inter-/Intramolecular O-H Bond
Authors: Binti Abd Azes Nur Izzah Abd , Yang Lechen , Choi Jaehoon , Reed Daniel , Kendrick Emma
Published: February 2024

Poly(ethylene oxide) (PEO) was first developed as a conducting polymer over a half-century ago and is still the most fascinating electrolyte matrix to use in solid-state batteries. Although thousands of articles have been published on the conductivity of various PEO-based solid-state electrolytes, none of the studies involved a higher EO-to-salt ratio up to 85 to 1. In this study, solid polymer electrolytes (SPE) based on the PEO-PEG complex with Sodium(I) Bis(trifluoromethanesulfonyl)imide (NATFSI) were prepared using the solid-state synthesis methods. The measurement using the Electrochemical Impedance Spectroscopy (EIS) technique demonstrated that EO70Na - 9PEO:3PEG has the most optimum PEO-PEG-NATFSI electrolyte system with conductivities of 0.01 mS/cm and 0.13 mS/cm at 25 °C and 50 °C, respectively. As reported in published articles, the conductivity of the EO to Na ratio started to decline from 15:1 to 25:1 with the dropped in NATFSI concentration. Further decline of Na concentration with the addition of EO from 40 to 70 ratio indicates a new increasing trend for the conductivity series, which result in a bimodal graph distribution. Fourier transform infrared (FTIR) spectral studies for PEO-PEG-based SPE revealed that vibrational changes of intramolecular -OH change as the concentration of short-chain polymer backbone and salt varies. The Raman spectral studies for PEO-PEG-based SPE proposed that the percentage of bis(trifluoromethane)sulfonimide anion (TFSI- anions) increases with the increase in ratio from 15 to 70 of EO to Na. It is proposed that a higher percentage of both intramolecular -OH and TFSI- anions are crucial in providing high conductivity value. The structure of complexed PEO-PEG-based SPE from XRD suggested that the crystalline domain of SPE decreased with the smaller amount of NATFSI.
Basicity and Stability of Argyrodite Sulfide-Based Solid Electrolytes
Authors: Jiang Shi-Kai , Yang Sheng-Chiang , Huang Wei-Hsiang , Wu She-huang , Su Wei-Nien , Hwang Bing Joe
Published: February 2024

Argyrodite-type sulfide-based solid electrolyte Li6PS5Cl (LPSC) holds immense promise for solid-state battery applications. This is attributed to its stable structure and high ionic conductivity. Nonetheless, the persistent challenges involving the instability at the electrode/electrolyte interface and susceptibility to moisture present significant obstacles in material preparation and cell manufacturing processes. Our research has unveiled a noteworthy finding: the sulfur of the PS4
3− moiety is a Lewis-base active site to adsorb Lewis acid. It is found that the adsorption of CO2 on the sulfide electrolytes can enhance both the interfacial and electrochemical stability of the lithium and sulfide electrolyte interface. The formation of new S–CO2 bonds, confirmed using various analytical techniques, plays a pivotal role in modifying the interfacial behaviors of the sulfide electrolytes. Moreover, the LijCO2@LPSCjLTO shows an amazing result, with 62% capacity retention and ultra-high coulombic efficiency of 99.91% after 1000 cycles. Interestingly, the same concept was also applied to the high ionic conductivity sulfide-based superionic conductor Li10GeP2S12 (LGPS) system, which also has the PS4
3− moiety. A novel approach is also developed by utilization of the BBr3 gas as a Lewis base indicator to probe the strength of Lewis basicity of the sulfur sites of sulfide electrolytes. The basicity of the sulfide electrolytes can be correlated to the shift of 11B NMR peak. This correlation is further supported by the H2S generation rate when the electrolyte is exposed to a moisture atmosphere. This work not only provides a new pave towards enhancing stability at the sulfide electrolyte/lithium interface but profound insights into the basicity and moisture stability of sulfide electrolytes.
Theoretical Study of Nucleation and Growth in Lithium Metal Batteries
Authors: Morey Madison , Ryan Emily
Published: February 2024

The Lithium (Li) Metal Battery (LMB) has shown promise in overcoming the energy storage limitations of the Lithium Ion Battery (LIB) due to the high theoretical capacity of the Li Metal anode. However, it is hindered by an unstable interface and uncontrolled dendrite growth leading to a decrease in coulombic efficiency and safety concerns. While it is difficult to study the electrode-electrolyte interface operando, computational methods can be used to resolve the interface and track the complex physical and chemical phenomena at this location. Specifically, we can use computational modeling to better understand the morphological evolution of deposited Li starting from the nucleation of Li through the growth of the dendrite. In this work we propose a computational method that combines nucleation physics, deposition, and ion transport to study how surface energy and defects impact Li deposition. It is observed that when defects increase the surface energy the nucleation rate decreases resulting in less dendritic growth and more homogenous plating.
A Perspective on the Use of Physics-Inspired Machine-Learned Molecular Force Fields on Battery Physics
Authors: Sauceda Huziel E.
Published: February 2024

A great amount of work has been done in battery physics, but a particularly pressing issue remains, to understand of the dynamical properties of battery elements at the atomistic level. Machine learned (ML) molecular force fields (FF) has contributed to nano-scale simulations of conventional materials. Nevertheless, the description of the highly complex and fluxional environments in batteries is beyond the reach of conventional ML models. Here, we’ll present a perspective on the potential use of new generation ML-FFs and how physics-biased models should be the developing direction to accurately describe, for example, materials densely packed with ion or ions in electrolytes.
Lithium Distribution and Site Disorder in Halide-Substituted Lithium Argyrodites: A Structural and Transport Study
Authors: Gautam Ajay , Wagemaker Marnix
Published: February 2024

Lithium argyrodite superionic conductor has recently gained significant attention as a potential solid electrolyte for all-solid-state batteries because of its high ionic conductivity and ease of processing. One promising aspect of these materials is the ability to introduce halide (Li6-xPS5-xY1+x, Y = Cl and Br ) into the crystal structure, which can greatly impact the lithium distribution over the wide range of accessible sites and structural site-disorder between the S2₋ and Y₋ anion on Wyckoff 4d site, strongly influences the ionic conductivity. However, the relationship between halide substitution, structural site-disorder, and lithium distribution is not fully understood. In this study, we investigate the effect of halide substitution on lithium argyrodite and engineer site-disorder by changing the synthesis protocol. We reveal the lithium substructure and ionic transport correlations using neutron diffraction, solid-state NMR, and electrochemical impedance spectroscopy, We find that higher ionic conductivity is correlated with a negative charge on the 4d site, as replacing the S2− with Br− leads to a lowered average charge on the 4d site and weaker interactions within the Li+ “cage”, promoting a migration pathway for Li+ ions across the Li+ cage. We also identify a new T4 Li+ site, which enables an alternative jump route (T5–T4–T5) with a lower migration energy barrier. The resulting expansion of Li+ cages and increased connections between cages leads to a maximum ionic conductivity of 8.55 mS cm-1 with higher site-disorder, an improvement of 11-fold compared to lower site-disorder. Overall, this work provides a deeper understanding of the structure-transport correlations in lithium argyrodite, specifically how site-disorder and halide substitution impact the lithium substructure and transport properties.
Laser-Induced Printing of Next Generation Silicon-Graphite Anodes for the Development of Advanced Lithium-Ion Batteries
Authors: Rist Ulrich , Sterzl Yannic , Falkowski Viktoria , Pfleging Wilhelm
Published: February 2024

The expansion of renewable causing a rising demand for affordable and improved energy storage systems. Lithium-ion batteries (LIB) are one of the most promising technologies for this achievement, with further improvements to be made in terms of new materials and an advanced electrode architecture. As a new generation electrode material to be included in LIB, silicon is in the focus of the today’s investigations. Silicon offers one order of magnitude higher theoretical specific capacity (3579 mAh/g) compared to the state-of-the-art material graphite (372 mAh/g). However, during lithiation of silicon a volume expansion of up to 300 % takes place. Due to the huge volume expansion tremendous mechanical degradation of the anode occurs, resulting in a drop in capacity and a shorten lifetime.

Laser induced forward transfer (LIFT) is applied in this study as printing technology to develop enhanced silicon-graphite electrode compositions and electrode architectures. LIFT was performed using a pulsed nanosecond UV-laser with a maximum power of 10 W and repetitions rate of up to 30 kHz. For the LIFT process of anodes, polyacrylic acid (PAA) is used as binder, in contrast to the polyvinylidene fluoride (PVDF) binder commonly used for LIFT assisted printing of electrodes. PAA is a more appropriate binder for silicon-containing anodes than PVDF. In addition, also a customized architecture using subtractive and additive laser process techniques is introduced for an increase in lifetime of batteries containing silicon-based electrodes. For this purpose, graphite electrodes were structured with an ultrashort pulse laser with pattern widths of 100 µm. Subsequently, silicon rich slurry was printed into the patterns to increase the areal capacity. The as-prepared electrodes have spatially separated graphite and silicon regions. The respective electrodes were electrochemically cycled in half-cells and charged at different C-rates up to 5C to investigate their lithiation capability. After the rate capability analysis, the cells were cycled at C/2 to investigate the long-term degradation. The cells with the printed electrodes were cycled for more than 450 cycles with a capacity fade of 5 %. At their end-of-life, the cells were analyzed post-mortem. Finally, full-cells were assembled with cathodes containing NMC 622 as the active cathode material. Subsequently to the cell priming a lifetime analysis was performed at a C-rate of C/2 and cycle stability as well as lithium loss during cycling were evaluated.
(Digital Presentation) Electrospun N-Doped CNFs Embedded Metal Oxides with Improved Graphitization for Superior Pseudocapacitive Energy Storage
Authors: Tanwar Vaishali , Parashar Ajay , Gujare Aditi Ashok , Ingole Pravin P
Published: February 2024

One-dimensional carbon nanofibers (CNFs) based pseudocapacitive hybrid electrodes are the next step forward in achieving highly efficient supercapacitor(SCs) electrodes. However, it is still a paramount challenge to develop rationally designed CNFs with sufficient pseudocapacitive surface functionalities, and adequate porosity via a facile synthesis for better practical applicability. Herein, we are reporting a single-step electrospinning methodology followed by carbonization to generate a unique spatial 1D structure with metal oxide (MO) particles embedded in CNFs (M-CNFs). By optimizing the polymer ratio with that of MO, it was possible to obtain an in-situ N-enriched porous CNF network generating a predominant pseudocapacitive charge-storing mechanism. The resulting material is a synergistic combination of MOs, and surface-enriched N-CNFs with good electrical properties and high surface area, suitable to be employed as electrodes for SCs. A deep investigation of the M-CNFs properties has been performed to understand the physical characteristics of the hybrid MO/CNFs material. Further, a flexible symmetric SC device exploiting the polymeric gel-based (PVA+ H2SO4) electrolyte was assembled delivering a maximum energy density of up to 50 Wh Kg-1 and capacitance retention of 90% with a coulombic efficiency of 95%, enabling both electric double-layer and pseudo-capacitance behaviors. The resulting performances of the here-proposed material allow the prediction of the enormous potentialities of these flexible energy-storage devices for industrial-scale application.

Keywords: surface N enrichment, electrospinning, hybrid CNFs, flexible symmetric supercapacitors.
Stability of Alizarin for Aqueous Organic Redox Flow Batteries
Authors: Maleki Meysam , Imhanria Sarah , Duguet Lisa , Goulet Marc-Antoni
Published: February 2024

The intermittent nature of renewable energy sources like solar and wind requires suitable large-scale energy storage technologies to properly respond supply and demand of energy. Aqueous organic redox flow batteries (AORFBs) have demonstrated great potential to revolutionize grid-scale energy storage as a result of their low-cost, safety and ability to separate energy and power1. However, most of the organic compounds suffer from lack of sufficient long-term stability.

Alizarin (1,2-dihydroxyanthraquinone) is a low-cost, nontoxic, and industrially accessible dye which could potentially be used as an affordable redox-active negative electrolye (negolyte)2. Here, we present an in-depth investigation on the long-term cycling stability of Alizarin. Furthermore, we implement an aggressive cycling conditions to investigate the degradation of the cycled negolyte within just a single day, achieving an equivalent capacity fade percentage as electrolyte cycled for over two weeks3. The capacity fade of alizarin was partially mitigated by the employment of a SOC restriction strategy which was able to decrease the capacity fade rate by more than 60 %.4 Capacity fade measured via cycling is corroborated by ex situ chemical analysis methods.

References:

(1) Kwabi, D. G.; Ji, Y.; Aziz, M. J. Electrolyte Lifetime in Aqueous Organic Redox Flow Batteries: A Critical Review. Chem. Rev.
2020, 120 (14), 6467–6489.

(2) Liu, Y.; Lu, S.; Chen, S.; Wang, H.; Zhang, J.; Xiang, Y. A Sustainable Redox Flow Battery with Alizarin-Based Aqueous Organic Electrolyte. ACS Appl. Energy Mater.
2019, 2 (4),

(3) Goulet, M.-A.; Aziz, M. J. Flow Battery Molecular Reactant Stability Determined by Symmetric Cell Cycling Methods. J. Electrochem. Soc.
2018, 165 (7), A1466–A1477.

(4) Goulet, M.-A.; Tong, L.; Pollack, D. A.; Tabor, D. P.; Odom, S. A.; Aspuru-Guzik, A.; Kwan, E. E.; Gordon, R. G.; Aziz, M. J. Extending the Lifetime of Organic Flow Batteries via Redox State Management. J. Am. Chem. Soc.
2019, 141 (20), 8014–8019.
Space Charges in Solid State Batteries: Friend, Foe or Fantasy?
Authors: Al-Kutubi Hanan , Ganapathy Swapna , Wagemaker Marnix
Published: February 2024

Thermodynamics tells us that all materials have an internal energy that determines how they act and react with all matter in the universe. Furthermore, it forces all matter to strive towards equilibrium with its surroundings. For solid-state lithium-ion conductors, the chemical potential of lithium is an important parameter that determines stability and influences conductivity. However, it also implies something deeper. The chemical potential of an element in a solid is determined by the bonds that surround it as well as its concentration. Whereas the former is an intrinsic property of the material, the latter can be altered. When two solids with different chemical potentials are placed in contact, a driving force is created for atoms to migrate across the surface and establish thermodynamic equilibrium by altering their concentration. For semiconductors, in which either only a hole or electron can migrate, something interesting occurs. The migrating entity moves across but the counter-charge cannot, resulting in excess charge at the interface. The migrating partner, unable to return to its original material due to thermodynamics, is now unable to dissipate into the new material due to electrostatics. The result is a thin, charged layer across the interface. Because solid electrolytes conduct lithium cations but no anions or electrons, this ‘space-charge layer’ is also thought to occur in solid-state batteries between electrolyte and electrode. Whereas its size is thought to only be a few nanometres, its (negative) influence could be very large as it can act as barrier for lithium transport across the surface. Yet experimental evidence of its existence is rare and investigation of its behaviour even more so. The space charge between two materials is very thin and chemically almost identical to the bulk. But just like how water can carve the stone, we employ liquids to crack a solid-state problem.

We find that when mixing an argyrodite solid electrolyte (Li6PS5Cl) with an ionic liquid (1-Ethyl-3-methylimidazolium bis(trifluoromethyls ulfonyl) imide or EMIN TFSI) , we observe a new chemical environment with NMR (see figure) that cannot be attributed to dissolved precursors. We see an increase in the mobility of lithium ions in the solid electrolyte itself with NMR and an increase in conductivity of the mixture with EIS. Furthermore, exchange of lithium has been confirmed between argyrodite and the mystery environment. What does this all mean? Are we observing the illusive space charge layer? Or are we just staring at an empty promise in the well-known shape of a mysterious peak in a spectrum?

Figure 1
Next-Generation Polymeric Organic Semiconductors for Electrochemical Transistors with Applications in Bioelectronics
Authors: LeCroy Garrett , Cendra Camila , Salleo Alberto , Giovannitti Alexander
Published: February 2024

Over the last decade, significant progress has been made in developing efficient mixed-organic-ionic-electronic conductors (OMIECs) for electrochemical transistors. Improvements in device performance for both transconductance and operational stability paved the way for applications of electrochemical transistors for health monitoring, neuromorphic computing, or electrochemical sensors. While the tuning of the energy levels (via backbone engineering) and the local environment of the polymers (via side-chain engineering) is reported to be a successful strategy for improving the electronic and ionic charge transport properties, little is known about how the short- and long-range order of polymers impacts the device performance.

In my talk, I will discuss the importance of microstructure and dynamic microstructural rearrangements of OMIECs which greatly influence the electronic charge transport properties in electrochemical transistors [1]. By combining electrochemical and spectroelectrochemical measurements alongside electrochemical X-ray diffraction measurements, we observe that holes and anions are placed in ordered aggregates and crystallites at relatively low charge carrier densities (< 2x1020 cm-3) for selected OMIECs, explaining the large increase in transconductance at low operational voltages. Moreover, we find that the electrochemical charging of p-type polymeric OMIECs induces structural order along the polymer backbones. We interpret this structural ordering as the key factor for achieving high transconductance since percolating networks can form more easily when polymer chains are planarizing. Surprisingly, these dynamic microstructural rearrangements are highly reversible, however only when high charge carrier densities are avoided where bipolarons are forming. Based on these findings, I will discuss chemical design strategies for next-generation OMIECs with improved transconductance and operation stability in electrochemical transistors.

[1] Garrett LeCroy, Camila Cendra, Tyler J. Quill, et.al., Role of aggregates and microstructure of mixed-ionicelectronic-conductors on charge transport in electrochemical transistors, Mater. Horiz., 2023, accepted.
Γ-Graphyne: A Promising Electron Acceptor for Organic Photovoltaics
Authors: Stasyuk Anton , Stasyuk Olga A. , Solà Miquel
Published: February 2024

The most significant discovery of recent years is graphene, which consists of a single layer of sp2-hybrid carbon atoms arranged in a two-dimensional (2D) honeycomb lattice nanostructure.Graphynes – a two-dimensional materials similar to graphene, but composed of sp-hybridized carbons periodically integrated into a sp2-hybridized carbon network. Structure of graphynes were first theoretically proposed in 1987 by Baughman et al.[1] More than 20 years later, in 2010, Li et al. developed the first successful methodology for creating γ-graphdiyne films [2]. Despite the significant attention from the scientific community, only recently Hu et al. reported the synthesis of γ
-graphyne with unified long-range crystalline structure [3].

We demonstrate that γ
-graphyne is an efficient electron acceptor due to its low LUMO and its ability to delocalize an excess charge. Moreover, in contrast to other 2D sheets like graphene its electronic properties are not sensitive to vacancy defects. Investigation of photoinduced electron transfer processes in complexes of γ
-graphyne with typical electron-accepting and electron-donating partners shows that the lowest excited states with donors are charge separated states formed by the electron transfer from partner to γ
-graphyne. This electron transfer is thermodynamically favorable and occurs on nano-to-picosecond time scale. In contrast, electron transfer from γ
-graphyne to strong electron acceptors such as fullerenes or arylenediimides is unlikely [4].

References:

[1] R.H. Baughman, H. Eckhardt, M. Kertesz, J. Chem. Phys. 1987, 87, 6687

[2] G. Li, Y. Li, H. Liu, Y. Guo, Y. Li, D. Zhu, Chem. Commun. 2010, 46, 3256.

[3] Y. Hu, C. Wu, Q. Pan, Y. Jin, R. Lyu, V. Martinez, S. Huang, J. Wu, L.J. Wayment, N.A. Clark, M.B. Raschke, Y. Zhao, W. Zhang, Nat. Synth. 2022, 1, 449.

[4] O. A. Stasyuk, A. J. Stasyuk, M. Solà, A. A. Voityuk, Mater. Des. 2023, 225, 111526.
Step Potential Electrochemical Spectroscopy (SPECS) Technique to Investigate the Ageing of Carbon Electrodes in Organic-Based Electrochemical Capacitors
Authors: Sroka Sylwia , Galek Przemyslaw , Fic Krzysztof , Menzel Jakub
Published: February 2024

Current research on electrode degradation in electrochemical capacitors (ECs) mainly focuses on the application of new materials and the establishment of their stability on the basis of various standards and qualitative tests. However, there exists limited research that focuses on the elucidation and determination of the degradation mechanisms and pathways of carbon electrodes. The proposed study uses an innovative approach with the use of the Step Potential Electrochemical Spectroscopy (SPECS) technique, which allows one to quantify the contribution of different charge-storing mechanisms, and successfully track any changes that take place after accelerated ageing, including structural changes of the electrode in the organic medium. Additionally, the role of oxygen content on the degradation of ECs was explored.

In this report carbon material, namely binder-free Activated Carbon Cloth (ACC) Kynol® 507-20 was prepared in a furnace under a nitrogen atmosphere at different temperatures, namely 120, 500, and 1000ᵒC. This is so that the effect of the presence of different oxygen functional groups on the surface of carbon could be investigated. The material was selected as a self-standing electrode to eliminate any influence the binder would have on the electrode porosity. Subsequently, these materials were prepared as electrode materials and assembled in a symmetric two-electrode setup with 1M TEABF4/AN (tetraethylammonium tetrafluoroborate in Acetonitrile solvent). In each cell, the potential range of both electrodes was first determined in a 2-electrode Swagelok® cell with RE using galvanostatic charge/discharge (1 A g-1). The further procedure involved 3 CV cycles (1 mV s-1) at a predetermined potential for each electrode in a 3-electrode set-up, followed by SPECS measurement where 5-minute potentiostatic hold with 10 mV potential steps was applied. The obtained current vs. time plots were used to calculate the corresponding capacitance, diffusion and residual parameters. Floating tests at 2.7 V were then carried out for each system. According to the international standard (IEC 62391-1), system failure is reported when the initial capacitance drops below 80% of its initial value; thus floating experiments were halted after that value was reached for each system or when the resistance of the cell doubled in value. The electrochemical investigation of the individual aged electrodes was then repeated in the same manner.

Our study allowed for a thorough examination of individual electrodes prior to and after floating experiments, which helped to elucidate the degradation causes and pathways in organic medium.
A Sustainable Li-Ion Capacitor Using Sawdust-Derived Activated Carbon Cathode Paired with Prelithiated Al Foil Anode
Authors: Guo Xiaoyang , Zheng Tianye , Zhang Jia , Wahl Markus Solberg , Burheim Odne , Boles Steven T
Published: February 2024

Activated carbon (AC) has long been recognized as a promising electrode material for energy storage/harvesting devices. The extraordinarily high specific area (e.g., ~2000 m2/g) makes AC almost irreplaceable in some applications, such as electrical double-layer capacitors (EDLCs) and capacitive deionization (CDI). [1] Yet the production of AC is often a concern due to the release of unwanted contaminants, such as waste acids and gaseous CO/CO2, resulting from a series of processes involving heating, burning, and the use of strong acids.

In this work, we present an activated carbon cathode that is fabricated following a more sustainable approach, namely by using sawdust waste as the carbon precursor via a physical activation process to modify its surface area and porosity. With the electrochemical performances being characterized by designated cyclic voltammetry (CV), galvanostatic charge-discharge cycling (GCD), and electrochemical impedance spectroscopy (EIS), the activation parameters, such as temperature, activation time and activation gas composition, are expected to be optimized for various application purposes.

To quickly demonstrate the technical feasibility, a high-performance Li-ion capacitor (LIC) is assembled using the sawdust-derived AC cathode to pair with a piece of prelithiated Al foil anode (β-LiAl). [2] Such an LIC is considered a hybrid energy storage device that can potentially combine the high energy density of a Li-ion battery with the high power density of a supercapacitor. Despite decent electrochemical performances, the proposed LIC device using a waste-derived cathode and a simple metallic foil anode can indeed help to better realize sustainability. [3] It is believed that such a unique LIC architecture can be a promising alternative to conventional energy storage devices for various applications, such as renewable energy storage, electric vehicles, and portable electronic devices.
SHAKF-PU: Sage–Husa Adaptive Kalman Filtering-Based Pedestrian Characteristic Parameter Update Mechanism for Enhancing Step Length Estimation in Pedestrian Dead Reckoning
Authors: Tseng Chinyang Henry , Wu Jiunn-Yih
Published: February 2024

Step length estimation (SLE) is the core process for pedestrian dead reckoning (PDR) for indoor positioning. Original SLE requires accurate estimations of pedestrian characteristic parameter (PCP) by the linear update, which may cause large distance errors. To enhance SLE, this paper proposes the Sage–Husa adaptive Kalman filtering-based PCP update (SHAKF-PU) mechanism for enhancing SLE in PDR. SHAKF has the characteristic of predicting the trend of historical data; the estimated PCP is closer to the true value than the linear update. Since different kinds of pedestrians can influence the PCP estimation, adaptive PCP estimation is required. Compared with the classical Kalman filter, SHAKF updates its Q and R parameters in each update period so the estimated PCP can be more accurate than other existing methods. The experimental results show that SHAKF-PU reduces the error by 24.86% compared to the linear update, and thus, the SHAKF-PU enhances the indoor positioning accuracy for PDR.