bluuebunny/crossref_metadata_2025_split huggingface dataset:
(Invited) Electrochemically Active Materials: Meeting the High-Energy Density Challenge
Authors: Kumta Prashant Nagesh , Velikokhatnyi Oleg , Gaikwad Mayur , Kuruba Ramalinga , Blomgren George E 
Published: February 2024

Energy storage is at a vantage state serving as the primary engine critical for an energy independent global economy currently still very much dependent on tapping into the earth’s natural reserves aided by natural oil and gas exports. The Li-ion battery chemistry has evolved over the years and is at the forefront of secondary rechargeable battery systems, witnessing burgeoning and ever-increasing research activity ever since Sony commercialized the first Li-ion battery in 1990. There have been since then transformative advances in all areas of cathodes, anodes, and electrolytes. Despite much progress, however, lithiated transition metal oxides and carbon remain the preferred typical systems that have made it into the commercial systems currently deployed in the hitherto electric vehicles (EVs). The intense research for identifying higher energy density systems has drawn the attention of Li-air and Li-S systems, of late. The Li-S systems are of particular interest due to the promise of achieving 500 Wh kg-1, a major milestone in meeting the energy density needed for next generation EVs matching and exceeding the performance metrics of the internal combustion engine (ICE).
This presentation will discuss the materials challenges that need to be overcome in generating high-energy density cathodes and anodes as well as electrolyte additives to reach the grand challenge of 500 Whkg-1. Research efforts made in the areas of developing cost-effective and scalable new sulfur confinement systems with ability to confine high sulfur loadings of 4-6 mg/cm2 enabling trapping the pernicious polysulfide species combined with unique functional electrocatalysts aided by theoretical first principles calculations exhibiting the propensity to catalyze the formation of Li2S will be discussed. In tandem, progress made in generating new dendrite-free anodes and low-density current collectors exhibiting areal capacities as high as 15 mAh/cm2 with stable cycling over 100 cycles as well as electrolyte additives matching the cathode performance will be outlined.
(Invited) Binder Investigation for Silicon Electrode of Lithium-Ion Batteries
Authors: Lu Wenquan , Salpekar Devashish , Zhang Linghong , Zhang Sanpei , Qin Yan , Kubal Joseph , Polzin Bryant , Trask Stephen E. , Meisner Quinton , Zhou Xinwei , Liu Yuzi , Zhang Zhengcheng , Jansen Andrew N. 
Published: February 2024

Though the binder is not an active material and does not contribute capacity to lithium ion batteries (LIBs), it is an important ingredient for maintaining the integrity of the electrode, which helps to improve electrical contact between the active materials and conductive carbon black, improves the Li+ transport efficiency, reduces the internal resistance of Li-ion batteries and effectively depresses the crack formations and phase separation.
Polyvinylidene fluoride (PVDF) is a polymer that is commonly used as a binder for both anode and cathode materials in LIBs. However, it is not suitable for Si electrode due to its poor binding capability and stability. Viewed as a next generation anode material, Si has been extensively studied due to its extremely high theoretical specific capacity of 3578 mAh/g (assuming Li15Si4 as intermediate product). However, silicon undergoes huge volume variations during repeated discharge and charge, which requires a strong binder to maintain the electrode mechanical integrity. Developing a high strength binder for silicon anodes has been considered as an efficient pathway to alleviate various capacity decay pathways.
Polyacrylic acid (PAA) and its lithiated version (LiPAA), rich with carboxy function group, can provide stronger binding and are widely used as binder for Si electrode. In this work, we optimized Si electrode formulation by varying the binder composition. The optimized Si electrodes were electrochemically tested in both half cells and full cells. With improvement in electrochemical performance, cracks at the electrode level can still be observed for the cycled electrodes, which suggests that a stronger binder is required to mitigate volume expansion of Si electrodes and hold the particles together.
We further studied the polyimide (PI) materials as binders for Si anodes in an attempt to achieve more stable cycling performance. In this work, we explore various PI crosslinking conditions and their effects on electrochemical performance. The optimized silicon electrode exhibits a higher tensile strength than that of conventional PAA binder. The strong adhesion of the PI binder suppresses the structural collapse of the Si negative electrode during lithiation/delithiation, enabling good capacity retention and stable cycle life.
(Invited) Multifunctional Binders for High-Performance Rechargeable Batteries
Authors: Zhao Ran , Hu Zhifan , Lv Mengge , Wu Feng , Wu Chuan , Bai Ying 
Published: February 2024

Secondary battery plays a significant role in our daily life as well as in modern smart grids, which typically consists of an electrolyte and two electrodes determining the key parameters of the battery. Despite a small dose that usually less than 10%, the binder is a crucial component to keep the electrode integrity and ensure the high electrochemical performance. What`s more, the modification of binder could be conducted to alleviate or even eliminate the side effects raised by failure behaviors of the electrode active materials. However, the state-of-the-art binder optimization strategies still fall behind the rapid development of the novel electrode materials.
To improve the energy density of secondary batteries, high-capacity electrode materials have been explored, including silicon, sulfur, layered oxides, etc. However, their practical applications are hindered by various failure behaviors. Take Si as an example, though the Si-based anodes exhibit high capacity up to 4200 mA g-1, they undergo huge volumetric expansion (≈400%) during the electrochemical reactions, resulting in the cracking of active material particles, electrode exfoliation, continuous electrolyte consumption and progressive SEI formation. As a consequence, the capacity of Si-based electrode decreases dramatically along with cycling. The conventional binders that have been widely used in the rechargeable battery systems are typically linear polymers, which are unable to endure the high volume change and address other challenges raised by electrode materials such as low conductivity, unstable bulk structure and interface, etc. To increase the mechanical strength and the electrochemical stability of electrodes, the design of multi-functional binders is considered to be an effective strategy to meet various requirements of advanced binders for high-performance batteries simultaneously.
In this work, the synthesis and characterization of multifunctional binders for high-capacity electrode materials are demonstrated. By the introduction of intermolecular forces and chemical bonds, 3D networks are constructed and the ability for volume change accommodation are enhanced as well as the binding force. Moreover, the dynamic crossed links also endow the binders with self-healing ability, which could help to remedy the cracking issues in the advanced electrode materials. Due to the merits of the as-synthesized binders, the electrochemcial performance of the high-capacity electrode is significantly improved, demonstrating a promising strategy for next-generation energy storage systems.
Enhancing the Chemical Stability of Fluoride-Ion Batteries
Authors: Galatolo Giulia , Alshangiti Omar , Rees Gregory , Pasta Mauro 
Published: February 2024

Fluoride-ion batteries (FIBs) are a promising post-lithium-ion technology that has the potential to achieve energy densities of >600 Wh/kg at the stack level and use Earth-abundant materials.1 These characteristics make them ideally suited to meet the requirements of the green energy transition. The progress of FIBs, however, has been hindered by the lack of a suitable liquid electrolyte as well as a reliable and practical electrochemical testing configuration. The chemical compatibility of solvent, salts as well as other inactive components in the presence of the highly reactive F-ion is often overlooked, resulting in the generation of HF, HF2
- or other by-products. For example, polyvinylidene fluoride (PVDF) is still the standard binder used in FIBs, despite its well-known chemical instability in the presence of F-ions.2 Moreover, most liquid FIBs are tested using flooded cells, where the large excess of electrolyte used and, the absence of a separator often underplay more fundamental issues such as electrolyte degradation and capacity fading.
In this work, we report a F-ion conducting liquid electrolyte with excellent chemical stability and good transport properties. We accomplish this, by combining an organic fluoride salt with an imidazolium-based ionic liquid, both free from β-hydrogens. We also adapt electrode dry-processing methods, widely used in lithium-ion batteries, to produce chemically stable Pb-PbF2 counter electrodes. Our results demonstrate that chemical stability and realistic testing conditions can be achieved in FIBs.

Xiao, A.W., Galatolo, G., Pasta, M.; The Case for Fluoride-ion Batteries. Joule
2021, 5, 2823–2844

Marshall, J.E.; On the Solubility and Stability of Polyvinylidene Fluoride. Polymers
2021, 13, 1354
Inhomogeneous Degradation in Lithium-Ion Batteries: The Effect of Thermal Gradients
Authors: Offer Gregory James , Li Shen , Zhang Cheng , Zhao Yan , Marinescu Monica 
Published: February 2024

Understanding lithium ion battery degradation is a consequence of multiple, tightly coupled and non-linear degradation mechanisms. The interplay between these degradation mechanisms, and how the cell is used, gives rise to path dependent behaviour, and hence data driven approaches to model behaviour and predict lifetime rapidly become prohibitively expensive. Therefore, a physics based approach to model degradation is desirable.
In addition, all of the degradation mechanisms are a function of temperature, which adds another variable to the path dependency. To make matters worse, all cells experience internal thermal gradients during operation, which means the path dependency for different regions within a battery will be different. This leads to inhomogeneous degradation. After a few cycles, the degradation pathway of each region will then be affected not just by the thermal gradients and local current density but also by the state-of-health of that region, leading to complicated emergent behaviour.
Solving a physics based model with multiple degradation mechanisms, in a detailed 3-dimensional thermally coupled discretised model is also prohibitively expensive. Therefore, in this paper we present a thermally coupled distributed equivalent circuit model, with degradation functions built in, so each node can degrade at different rates, as a function of the operating conditions at that node. We have reproduced experimental data previously published, showing the effect of thermal gradients on degradation for two different cooling strategies for a tab and surface cooled pouch cell. For the first time reproducing the positive feedback mechanism responsible for accelerated degradation for surface cooling.
The results of this work show that thermal gradients cannot and should not be ignored, and degradation models that do not take them into account have a significant risk of overfitting and leading to incorrect conclusions.
Identifying Thermal Decomposition Mechanisms of the Solid Electrolyte Interphase with in-Situ Gas Analysis of Lithium-Ion Batteries
Authors: Schmidt Leon , Hankins Kie , Bläubaum Lars , Gerasimov Michail , Krewer Ulrike 
Published: February 2024

The global shift away from fossil fuels has generated an unprecedented demand for electric vehicles and a steady increase in the prevalence of lithium-ion batteries. Additionally, increases in the energy density of storage technologies has led to a corresponding increase in safety concerns regarding thermal runaway reactions. The components of a lithium-ion battery can self-react when exposed to an external heat source, which can cause a thermal runaway reaction process and large-scale fires of the cell. The initial reactions in this process involve the decomposition of the Solid Electrolyte Interphase (SEI) breakdown and conductive salt. The underlaying mechanisms behind these reactions are unclear; in-depth investigations are needed in order to develop a detailed understanding of the thermal runaway process and guide the development of strategies to mitigate the safety hazards posed by these battery systems. In the past, differential/online electrochemical mass spectrometry (DEMS/OEMS) was utilized to analyze the buildup of the SEI as well as decomposition due to overcharge. Our new methodology of high temperature (HT-)OEMS, with a maximum temperature of 132 °C, can simulate heating events with thermal ramps on an in-situ test cell battery. These measurements reveal information regarding reaction product gases and cell voltage drop during first formation and thermal stress tests, and provide novel insight into the electrochemical and thermodynamic phenomena during thermal abuse of lithium-ion batteries.
In this study, we use (HT-)OEMS to investigate the behavior of lithium-ion cells with varied additive concentrations and formation currents. This new methodology allowed us to clearly determine that both of the testing parameters impact the formation gas evolution and thus influence the SEI-composition. Systems with high formation rates, as well as with lower concentrations of additives, exhibited an increase in the fraction of CO product gases, which can be explained with a higher presence of lithium alkoxides in the SEI. Additionally, the evolution of H2, CO2 and POF3 gases were observed at temperatures around 80 °C for cells during the thermal stress test after formation. These results allow us to establish a correlation between the thermal conductive salt decomposition and the formation of the SEI-components Li2CO3 and (CH2OLi)2.
The identification of the underlying degradation mechanisms and process correlations via (HT-)OEMS provides a novel and important understanding of the phenomena that give rise to thermal runaway in lithium-ion batteries. This cell chemistry-based insight can be used to guide future prevention-focused safety assessments.

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(Keynote) Rapid Thermal Management for Fast Charging of Energy-Dense Lithium-Ion Batteries
Authors: Wang Chao-Yang , Liu Teng , Yang Xiao-Guang , Ge Shanhai , Stanley Nathaniel V. , Rountree Eric S. , Leng Yongjun , McCarthy Brian D. 
Published: February 2024

Charging time trauma refers to the pain experienced by electric vehicle (EV) owners when the ‘refill’ time is significantly longer than that of traditional internal combustion engine vehicles. Worsening this trauma is the inconsistency of EV charging; for example, the same EV may take five times longer to charge on a cold day. Faster charging will alleviate this pain point and aid in the mass adoption of EVs, crucial for meeting near-term carbon emission goals. Reaching this goal will require smarter and more rapid thermal management to provide significantly faster safe charging.
The results from the 2022 Nature article “Fast charging of energy-dense lithium-ion batteries” (DOI 10.1038/s41586-022-05281-0) where 265 Wh/kg lithium-ion pouch cells were charged from 0-70% in less than 12 minutes, 2,000 times in a row before end-of-life, will be presented. These cells used only proven materials, including a liquid electrolyte made from industrially-used components, and energy-dense, EV-grade electrodes. Key to success was smart cell thermal management. More recent advancements, including multi-cell battery-level data, will also be discussed.

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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.
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.

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