bluuebunny/crossref_metadata_2025 huggingface dataset:
Rapid Inverse Parameter Inference Using Physics-Informed Neural Networks
Authors: Hassanaly Malik , Weddle Peter J , Randall Corey R , Dufek Eric J. , Smith Kandler
Published: August 2024

As Li-ion batteries become more essential in today's economy, tools need to be developed to accurately and rapidly diagnose a battery's internal state-of-health. Using a Li-ion battery's (high-rate) voltage response, it is proposed to determine a battery's internal state through Bayesian calibration.

However, Bayesian calibration is notoriously slow and requires thousands of model runs. To accelerate parameter inference using Bayesian calibration, a surrogate model is developed to replace the underlying physics-based Li-ion model. Developing a surrogate model for rapid Bayesian calibration analysis is discussed for both the single particle model (SPM) and the pseudo two-dimensional (P2D) model.

Surrogate models are constructed using physics-informed neural networks (PINNs) that encode the influence of internal properties on observed voltage responses. In practice, a neural network can be trained by: 1) using simulation results of the physics-based model (i.e., a data-loss approach); 2) using the residuals of the governing equations themselves (i.e., a physics-loss approach); or 3) using a combination of simulation results and governing equation residuals. In the present work, PINNs are developed using a variety of training losses and neural network architectures. In this analysis, it is shown that a PINN surrogate model can be reliably trained with only physics-informed loss. However, using a coupled data-informed and physics-loss approach produced the most accurate PINNs. Figure~\ref{fig:spm_2d} illustrates the absolute relative errors of trained PINN networks using several different training losses and neural network architectures.

After determining a consistent training strategy for both the SPM and P2D PINN surrogate models, the PINNs are extended to determine additional internal state-of-health parameters. As more and more parameters were introduced, the PINN training suffered from ``the curse of dimensionality", which was mitigated by using a hierarchical training approach (where a PINN trained with fewer variable model parameters was used to train a PINN with more variable model parameters).

Next, the high-dimensionality PINN surrogates are then integrated into Bayesian calibration schemes to identify internal Li-ion battery properties from experimentally measured voltages. Interpreting the high-dimensional parameter posteriors is discussed with respect to model error, parameter prior choices, and experimental errors.

Figure 1
A New Class of Lithium Conductive Polymers for Solid State Lithium Metal Batteries at Room Temperature
Authors: Wang Peng , Bucur Claudiu , Andrei Petru
Published: August 2024

Lithium-ion batteries (LIBs), among various secondary battery technologies, have received a significant amount of attention in the last decades, becoming the most successful commercial batteries. Extensively used in portable electronics, electric vehicles, and energy storage stations, LIBs meet many challenges, such as safety problems, low energy densities and so on, which drives much research toward developing the next generation of battery technology. Solid-state batteries emerge as one of the most potential alternatives for mainstream LIBs. Polymer-based solid-state electrolytes (SSEs) have been widely studied due to their softness and flexibility, relieving interface problems between electrodes and separators, especially compared with inorganic solid electrolytes. However, their limitations, such as limited Li+ conductivity or narrow electrochemical windows (< 4 V), restrict their potential applications. In this presentation, a new type of polymer (PG23), developed by Piersica Inc. (www.piersica.com) were applied as excellent binder to organic electrolyte based LIBs, and also to all solid state LIBs. Solid state electrolyte (SSEs) based on the polymer PG23 exhibits impressive conductivity (0.1 mS/cm) at room temperature and extremely high oxidized stability (approx. 4.9 V). When the SSEs was applied to both solid cathode (NMC622 as active material) and SSEs, combined with Li metal as anode, the LIBs demonstrated excellent capacity and cycling stability operating at room temperature. This polymer from Piersica Inc. exhibits considerable promise for the development and enhancement of solid-state batteries.
Enhancing Cycling Stability of Li Metal Batteries by a Bifunctional Fluorinated Ether
Authors: Tran Nhan , Cao Xia , Xu Yaobin , Gao Peiyuan , Han Kee Sung , Engelhard Mark H. , Wang Chongmin , Xu Wu , Zhang Ji-Guang
Published: August 2024

Passivation of both anode and cathode surfaces by the inorganic-rich solid electrolyte interphases (SEI) is a very efficient approach to extent the cycle life of rechargeable high-voltage lithium (Li) metal batteries (LMBs). In this work, a fluorinated ether with weakly-solvating ability, termed DB, was used as a diluent as well as a co-solvent in the localized high-concentration electrolyte (LHCE) system, which contains LiFSI salt, 1,2-dimethoxyethane solvent, and DB. Dissimilar to most reported inert diluents, DB is demonstrated to form an anion-rich solvation sheath and partially participate in the solvation structure as well, resulting in the relatively weakened FSI--Li+ coordination, which significantly enhanced anion decomposition kinetics at the Li metal surface, promoting the formation of inorganic-rich SEI. With an optimized electrolyte, the SEIs of both the anode and cathode consist of inorganic-rich components with F, N, S, and O-containing species. Consequently, the full-cell with Li metal and NMC811 cathode at 4.4 V achieved long cycle life of 478 cycles at 80% capacity retention, which provides new perspective toward practical high-voltage battery systems.
Non-Combustible Electrolyte for Fast Charging Lithium-Ion Batteries
Authors: Oh Taekeon , An Kihun , Tran Yen Hai Thi , Lee Hyeongyu , Song Seung-Wan
Published: August 2024

Lithium ion batteries (LIBs)-powered electric vehicles have been increasing their share in the market. Currently, the commercially available charging rate is 0.3C, which takes more than 3 hours to fully charge. This is a factor that causes inconvenience to customers. In the case of fast charging, however, lithium dendrites are formed in the battery, which deteriorate battery life and cause battery short circuits leading to fire and explosions. In the event of an electric vehicle fire, the combustible organic solvent in the electrolyte acts as fuel. Although it is evident that safety of transportation should be guaranteed, electric vehicles fires occur frequently and users are concerned about this. Addressing battery safety issue, herein, we report development of a new class of electrolyte that is non-combustible and capable of 10 times faster charging than the commercial one. In this meeting, the effects of non-combustible electrolyte on anode and cathode interfaces under fast charging condition will be discussed.

Acknowledgements

This research was supported by the National Research Foundation grant funded by the Ministry of Science and ICT (RS-2023-00217581, RS-2023-00260261) of Korea.
Improved Silicon/Graphite Composite Anode for High-Energy Li-Ion Battery
Authors: Varma Akash , Karam Zainab , Busa Chiara
Published: August 2024

High-specific capacity of Silicon (~ reaching up to 3600 mAh/g corresponds to Li15Si4) and relatively higher lithiation potential (~0.4V Vs Li+; helpful in avoiding plating) makes it an ideal candidate for high-energy Li-ion batteries (LIBs). However, it is faced with severe issues like high crystallographic expansion (~320%), slow lithium diffusion, and high reactivity with electrolyte at higher SOCs. All of it leads to particle cracking, isolation, and electrode delamination resulting into poor cycle life performance. To harness the true potential of Silicon, we proposed an improvised Si/Gr composite anode balancing the high-specific capacity and cycle life. We investigated a novel binder formulation for Si-rich/Gr composite to enable high-specific capacity without compromising on life cycle. We demonstrated a robust and stable solid-electrolyte interface (SEI) formation by optimizing the electrolyte additive and formation protocol. Coupling our Si/Gr anode with high-energy Ni-rich cathode at appropriate capacity ratio (N/P) provides high-energy density (> 400 Wh/Kg) for LIBs.
Profile of Round-Trip Efficiency of Lithium-Ion Battery Energy Storage System
Authors: Arima Masahito , Lin Lei , Fukui Masahiro
Published: August 2024

Lithium-ion battery energy storage systems (Li-BESSs) are expected to adjust variable renewable energies such as photovoltaic energy. In the viewpoint of the energy management cost, profiles of round-trip efficiency (RTE) are important characteristics of Li-BESSs. The profiles of RTE are related to the characteristics of both LIBs and inverters installed on Li-BESSs. The characteristics of Li-BESSs would be various because of reusing and degradation of lithium-ion batteries (LIBs). And inverters made by a lot of manufacturers would be so on. Accordingly, it could be said that the understanding of the profile of each Li-BESS’s RTE is complex and difficult.

Therefore, we studied the time series analysis of operation data and tried to estimate the characteristics of both LIBs and inverters. The important ones of LIB are full-charge capacity (FCC), open-circuit voltage (OCV), and internal resistance (R). In addition, characteristics of OCV and R can be expressed as function profiles with state of charge (SOC) as elements. Similarly, the important one of inverter is the typical efficiency curve. In this study, we proposed the estimation method of the profiles of OCV and R and inverter efficiency curve. On the other hand, FCC was given as assuming that general diagnosis results would be provided. Then, a RTE profile of Li-BESS (including 9.94kWh LIB and 10kW inverter) was tried to establish from the results of it.

The profiles of OCV and R were estimated by the method called MGFFD (Modified Gaussian Free-Form Deformation) that we have been established [1]. The novelty of this study could be described as:

Development of the estimation method of an efficiency curve of inverter installed on BESS during operation (Fig.1).

Quantitatively visualized profile of RTE of Li-BESS by combining results of MGFFD estimation applied for LIBs and inverter (Fig.2).

The profile described on Fig.2 is the relationship between SOC, input-output power rate of inverter, and RTE of Li-BESS. To understand Li-BESS’s charge-discharge efficiency of from state at that time to the end of an operation plan, it would be necessary information. This proposed method could clarify various RTE of Li-BESSs, consequently, be useful for its efficient operation by information communication technology.

Reference

[1] M. Arima, L. Lin, and M. Fukui, "Kalman-Filter-Based Learning of Characteristic Profiles of Lithium-Ion Batteries", Sensors, vol. 22, no. 14, 5156.

Figure 1
Operando Raman and in-Situ UV-Vis Spectroscopy Unveil the Impact of Solvent Donor and Acceptor Numbers on Gel Polymer Electrolytes in Lithium-Sulfur Batteries
Authors: Gomes Luisa Larissa Arnaldo , Dai Huidong , Sanctis Victor , Mukerjee Sanjeev
Published: August 2024

Lithium-sulfur (Li-S) batteries boast a specific capacity five times greater than current Li-intercalation systems. Still, practical implementation faces challenges tied to liquid electrolytes, i.e., lithium metal dendrites formation, polysulfide redox-shuttle, and flammability [1]. Thus, we focus on developing biodegradable gel polymer electrolytes to overcome these issues, fostering eco-friendly, safer, and more effective energy storage solutions. Polycaprolactone (PCL) emerges as a promising GPE candidate due to its biodegradable nature and broad stability range (~5V vs Li0/Li+). Our current study investigates the influence of solvent selection, explicitly focusing on donor and acceptor numbers, in formulating gel polymer electrolytes for Lithium-Sulfur batteries. Leveraging operando Raman and in-situ UV-Vis spectroscopy, our research provides real-time insights into the dynamic interactions within the gel during battery operation, shedding light on the evolving electrochemical processes. Moreover, by systematically analyzing the impact of solvent properties on gel characteristics, we reveal a nuanced relationship, emphasizing the importance of tailored solvent selection for optimizing gel performance. Operando Raman spectroscopy enables the observation of bond formations and structural changes in the gel, while in-situ UV-Vis spectroscopy tracks the behavior of polysulfides, facilitating the identification of specific interactions and offering a comprehensive understanding of the gel's role in mitigating polysulfide shuttling. This work aims to advance our fundamental knowledge of gel polymer electrolytes and provide a pathway for optimizing battery performance and mitigating degradation mechanisms. Notably, our study introduces a novel dimension by employing a custom-built UV-Vis setup, enhancing the versatility and applicability of these spectroscopic techniques in probing the intricate interactions within gel polymer electrolytes.

Reference

1-Pervez, S. A.; Vinayan, B. P.; Cambaz, M. A.; Melinte, G.; Diemant, T.; Braun, T.; Karkera, G.; Behm, R. J.; Fichtner, M., Electrochemical and compositional characterization of solid interphase layers in an interface-modified solid-state Li–sulfur battery. Journal of Materials Chemistry A2020,
8 (32), 16451-16462.
Uncovering Reduction Mechanisms of Fluoroethylene Carbonate
Authors: Ramesh Sapna L , Lopez Jeffrey
Published: August 2024

Energy storage plays an integral role in climate change mitigation, given that many promising alternatives to fossil fuel-based technologies rely on intermittent energy sources like the sun or wind. Particularly, lithium metal batteries (LMBs) are a promising technology due to lithium’s high theoretical specific capacity and low reduction potential, which can result in batteries with energy densities surpassing current state of the art lithium-ion batteries.1 Electrolyte design is a key strategy to improve the cycling stability and Coulombic efficiency of LMBs, where the highly reductive lithium metal anode reacts with the electrolyte during cycling, resulting in capacity loss. These reactions form a solid electrolyte interphase (SEI), and many successful electrolyte engineering strategies have involved tuning the SEI to be mechanically and chemically stable to prevent further reactions.

In this research, we focus on fluoroethylene carbonate (FEC), a highly effective electrolyte solvent in LMBs.2 Although prior research has illuminated key reduction products of FEC2,3, including lithium fluoride (LiF), there remains a gap in understanding regarding the mechanism by which FEC and other similar fluorinated solvents are reduced to form an SEI. Furthermore, recent research has demonstrated that a preformed SEI comprised solely of LiF breaks down during cycling, illustrating that bulk chemical and mechanical properties of SEI components may not translate to their function within the SEI.4 In this work, we employ electron paramagnetic resonance (EPR) spectroscopy to study intermediate generation during FEC reduction. We pursued both a chemical reduction using lithium naphthalenide and an electrochemical approach to reduce FEC. The use of EPR with spin traps enables insight into the radical species formed during FEC reduction, which we hypothesize are precursors to cross-linked polymer networks that are key to a high performing SEI. Here, we employed conventional post-mortem SEI analysis like X-ray Photoelectron Spectroscopy (XPS) in addition to EPR to clarify reduction mechanisms of FEC and form a framework for studying electrolyte reduction intermediates. Ultimately, this approach affords insight into electrolyte breakdown mechanisms to form an effective SEI which can both accommodate volume expansion and inhibit parasitic electrolyte consumption. This will guide electrolyte design for high Coulombic efficiency LMBs in the future.

References

K. G. Gallagher et al., Energy Environ. Sci., 7, 1555–1563 (2014).

X.-Q. Zhang, X.-B. Cheng, X. Chen, C. Yan, and Q. Zhang, Advanced Functional Materials, 27, 1605989 (2017).

Y. Jin et al., J. Am. Chem. Soc., 139, 14992–15004 (2017).

M. He, R. Guo, G. M. Hobold, H. Gao, and B. M. Gallant, Proceedings of the National Academy of Sciences, 117, 73–79 (2020).
“Zero” Porosity High Loading NMC622 Positive Electrodes for Li-Ion Batteries
Authors: Alolaywi Haidar , Uzun Kubra , Cheng Yang-Tse
Published: August 2024

LiNi0.6Mn0.2Co0.2O2 (NMC622) is a widely used positive electrode material for lithium-ion batteries, including electric vehicles. In this work, we investigated the effects of porosity, ranging from “zero” to the typical 35%, on the electrochemical behavior of high-loading NMC622 electrodes. Although it is well known that the energy density of the electrode increases with increasing areal capacity and decreasing porosity, NMC-positive electrodes with exceedingly low porosity (e.g., near zero) and high loading (e.g., 4 mAh cm-2) have not been investigated. Here, we report an intriguing observation that the “zero porosity” NMC electrode can have higher capacity at low C-rates, and the volumetric energy density significantly increases to 1739 Wh L-1 compared to 805 Wh L-1 of conventional electrodes of 35% porosity. We performed cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS) to help understand this observation. This work provides new insights into the effects of porosity on the electrochemical behavior of high-loading positive electrodes.
Impact of High-Temperature Storage on Capacity Fade of Ni-Rich Cathodes in All-Solid-State Batteries
Authors: Seok Jangwhan , Yoon Won-Sub
Published: August 2024

Despite the extensive research efforts focused on enhancing the lifespan and energy density of all-solid-state batteries, the calendar aging behavior of cathode material within the all-solid-state batteries system continues to be underexplored. In this study, we elucidate the capacity fade behavior of Ni-rich cathodes in all-solid-state batteries after high-temperature storage using electrochemical techniques, synchrotron X-ray-based characterization tools, and electron microscopy. High-temperature storage degrades the electrochemical performance of the Ni-rich cathode, constraining the capacity for charging and discharging the electrode. A larger portion of capacity loss is attributed to extensive charge fading, resulting from structural reconstruction on the cathode surface during high-temperature storage. The application of a LiNbO3 coating layer effectively inhibits the interfacial degradation, virtually eliminating both types of fading. These findings offer a deeper understanding of the storage-induced capacity fades of Ni-rich cathodes in ASSBs.
Cation-Doped Nasicon-Type Electrolyte for Lithium-Ion Batteries
Authors: Chen Yen-Lin , Lu Wen-Hsuan , Chen Han-Yi
Published: August 2024

In response to the global challenge of climate change, scientists are actively engaged in developing diverse energy storage solutions. Among these, lithium-ion batteries (LIBs) remain the most prevalent due to their high energy density and reliable cycling performance. Nonetheless, the liquid electrolytes utilized in LIBs pose safety concerns, including the risk of combustion and explosion. To address these issues, extensive efforts have been directed towards the development of solid electrolytes, which offer enhanced thermal stability, thereby improving safety during usage. However, solid electrolytes face challenges such as low ionic conductivity and suboptimal contact with electrodes.

Li1.3Al0.3Ti1.7(PO4)3 (LATP) stands out as a promising lithium-ion solid electrolyte, characterized by relatively high ionic conductivity and chemical stability in atmospheric conditions. This study first optimized the stoichiometric ratio and heat treatment during LATP synthesis. The resulting LATP exhibited an ionic conductivity of approximately 4 × 10-4 S/cm at room temperature. Additionally, efforts were made to substitute Ti4+ with another element in the lattice sites, inducing slight lattice distortion and promoting the segregation of a Li-ion-conductive second phase at grain boundaries. Consequently, the ionic conductivity of cation-doped LATP was successfully enhanced to 8 × 10-4 S/cm at room temperature.

Nevertheless, an inherent challenge faced by LATP involves its reactivity with lithium metal, posing a significant threat to the cycle life of LIBs. To mitigate direct contact between LATP and lithium metal, a protective layer composed of Poly(vinylidene fluoride-co-hexafluoropropylene) (PVDF-HFP) membrane was introduced. This not only prevented direct contact but also substantially improved the contact resistance. The culmination of these advancements led to the assembly of an all-solid-state lithium-ion battery (ASSLIBs) comprising PVDF-HFP, cation-doped LATP ceramic pellet, LiFePO4 cathode, and Li anode.
Surface Modification of Cellulose Films By Dielectric Barrier Discharge for Organic Photovoltaics Encapsulation
Authors: Saget Manon , Umeileka Chisom , Svandova Lucia , Lavoine Nathalie , Laroche Gaétan , Profili Jacopo
Published: August 2024

Organic photovoltaics (OPV) are the third generation of solar cells and are more and more attractive for industrial applications. OPV present numerous advantages, such as flexibility, low cost, light weight, large-area production.[1,2] Nonetheless, OPV are not as efficient as the conventional crystalline silicon photovoltaic (PV) cells. Recently, power conversion efficiency (PCE) has reached 18% for OPV, while conventional PV remains around 30% [3]. In this sense, additional works are necessary to improve their processability. Moreover, components of OPV are highly sensitive to water or oxygen, which strongly affect OPV stability in time when used in harsh conditions. Therefore, development of new barrier coatings are today essential to reduce OPV degradation and increase their shelf life. According to the literature, encapsulation can be performed following three strategies: (i) glass-glass encapsulation, (ii) flexible polymer lamination and (iii) thin film direct deposition. Glass-glass encapsulation provides great protection, with good optical properties but it remains fragile and is not compatible with roll-to-roll processes. On the other hand, although, flexible polymer lamination is suitable for roll-to-roll processes, adhesion between the front and back barriers is still complex to deal with, leading sometimes to partial encapsulation, thus increasing OPV degradation. Finally, direct deposition allows to obtain thin films with excellent optical and oxygen and humidity barrier properties. To date, most of thin layers are synthesized under vacuum [1,2]. This work focus on the development new barrier coatings at atmospheric pressure, compatible with roll-to-roll processes using cellulose nanofibrils with excellent oxygen barrier properties [4]. Being hydrophilic, the surface of cellulose nanofibrils have been modified to improve the water barrier properties. Wettability modification (WCA ~ 140°) was successfully achieved with an atmospheric pressure dielectric barrier discharge to control the fragmentation/reticulation of 2,4,6,8-Tetramethylcyclotetrasiloxane (TMCTS).

References:

[1] L.J. Sutherland, H.C. Weerasinghe, G.P. Simon, A Review on Emerging Barrier Materials and Encapsulation Strategies for Flexible Perovskite and Organic Photovoltaics, Adv Energy Mater. 11 (2021). https://doi.org/10.1002/aenm.202101383.

[2] S. Song, J. Lu, W. Ye, B. Zhang, X. Liu, G. Xing, S. Zhang, Stability, encapsulation and large-area fabrication of organic photovoltaics, Sci China Chem. 64 (2021) 1441–1459. https://doi.org/10.1007/s11426-020-1021-x.

[3] S. Bhattacharya, S. John, Beyond 30% Conversion Efficiency in Silicon Solar Cells: A Numerical Demonstration, Sci Rep. 9 (2019). https://doi.org/10.1038/s41598-019-48981-w.

[4] S.S. Nair, J. Zhu, Y. Deng, A.J. Ragauskas, High performance green barriers based on nanocellulose, Sustainable Chemical Processes. 2 (2014). https://doi.org/10.1186/s40508-014-0023-0.
Water Soluble Poly(amic acid) Binder for Anode Coating and High Temperature Processing
Authors: Zhu Tianyu , Liu Gao
Published: August 2024

The advent of lithium batteries has been a cornerstone in the evolution of electric vehicle technology, offering a sustainable alternative to fossil fuels and transforming the transportation landscape. The integration of water-soluble binders in the scalable production of anodes significantly enhances the efficiency and sustainability of lithium battery manufacturing. Further advances in battery manufacturing require enhanced tolerance to high temperatures and increased mechanical robustness, especially for high-throughput roll-to-roll production process. In this study, we present a water-soluble poly(amic acid)-based binder, uniquely designed to facilitate aqueous coating processes and withstand high processing temperatures for anode manufacturing. This innovative binder demonstrates remarkable efficiency in securely binding active materials, such as graphite or silicon, ensuring their integrity and performance throughout the battery cycling process.
Exploring the Nb-Ti-W-O System for Use as Li-Ion Battery Anodes
Authors: Sieffert James Michael , McCalla Eric
Published: August 2024

While much attention in recent years has been given to high performance Li-ion batteries for electrical vehicles, other applications such as medical devices require a unique set of properties that demand a different set of material considerations such as long lifetimes and extremely high safety. Anodes for such batteries must be carefully selected to properly achieve these goals. The most commonly industrially utilized anode material, graphite, is not suitable for medical applications due to particle fracture and Li dendrite growth at high rates. Currently utilized medical device anode materials obtain this high performance by sacrificing energy density.

Herein a new set of Nb based materials for use as anodes are presented that do not need to make such a sacrifice as they display high longevity along with high energy densities. The Nb-Ti-W pseudoternary features many promising single-phase compositions that could be used as anodes for such devices. These compositions derive from crystal structures that are found on both the Nb2O5-WO3 and Nb2O5-TiO2 pseudobinaries1, though they posses a more diverse range of chemical compositions. These compositions feature high performance discharge capacities of up to 300 mAh/g. Some materials also display robust capacity retentions of up to 98% after 10 cycles. The materials were also tested at 37 °C to simulate operation within the human body. At these temperatures, improvements were found in electrochemical performance for nearly all compositions, notably demonstrating a large improvement in capacity retention regardless of crystal structure.

References

(1) Rehman, S.; Sieffert, J. M.; Lang, C. J.; McCalla, E. NbyW1-yOz and NbxTi1-xOz pseudobinaries as anodes for Li-ion batteries. Electrochimica Acta
2023, 439. DOI: 10.1016/j.electacta.2022.141665.
Leveraging Advanced Analytical Chemistry Techniques to Probe Thermo-Electrochemical Aging Effects in Lithium-Ion Battery Electrolytes
Authors: Katzenberg Adlai
Published: August 2024

As lithium-ion and other battery chemistries gain market traction for grid and industrial-scale applications, pressure is mounting to develop more robust, longer lasting cells that can operate for hundreds of cycles at variable temperatures without sacrificing performance or safety. Electrolyte design is crucial to this effort and requires deep understanding of the correlated physical, chemical, and electrochemical factors that dictate long-term electrolyte performance. In this presentation, I will discuss the value of combined analytical chemistry techniques (solid- and liquid- state NMR, GCMS, and ICPMS) to resolve molecular-level impacts of thermally- and electrochemically- induced aging of lithium-ion electrolytes. In a model electrolyte, High Resolution (HR)-GCMS enables identification of subtle changes in solvent and additive chemistry while NMR reveals the formation of lithium-salt breakdown products. These findings are instructive for battery cycling as demonstrated by full chemical analysis of electrolyte extracted from aged lithium-ion cells, including evolved gas analysis, electrolyte deformulation, and SEI characterization. These cutting-edge analytical chemistry techniques are powerful and underutilized tools for detecting and mitigating failure modes in liquid electrolytes.
Towards Understanding and Control of Thermal Processes in Lithium-Ion Batteries
Authors: Yang Yuqiang , Kortekaas Luuk , Tromp Moniek
Published: August 2024

Despite lithium-ion batteries (LIBs) being state-of-the-art commercial rechargeable batteries, there are still significant challenges. For example, heat generation during cycling can lead to performance degradation and safety issues1-2. During the process of charging and discharging, the heat that is generated from the chemical reactions taking placing is ideally distributed uniformly in space, to dissipate out the cell easily. However, in practice, heat generation tends to be heterogeneous throughout the battery, leading to localized overheating3. This phenomenon can result in e.g. decomposition of the solid-state electrolyte interphase (SEI) layer, triggering electrode reactions with the electrolyte and degradation of the electrolyte (producing combustible gases) and even melting of the separator4. Hence, comprehending the origins of temperature generation and its heterogeneity is crucial.

To address this challenge, operando X-ray diffraction (XRD) and X-ray absorption spectroscopy (XAS) are applied to monitor the structural changes in the electrode materials during charge and discharge, while simultaneous temperature measurements are conducted using a thermal camera, as such obtaining spatial resolved structure/temperature/performance relationships. We have focused on state-of-the-art nickel rich NMC (Nickel Manganese Cobalt Oxide) versus graphite batteries and by comparing the structural changes of the electrode materials during cycling in ‘hot’ versus ‘cool’ areas of the electrode and battery, we were able to establish a structure-temperature relationships, on top of the electrochemical structure-performance relationships and as such unravel “heat-generation” process and reactions. The real-time temperature distribution was compared to the computational models using COMSOL, and insights in thermal processes and their possible control measures could be obtained.

References

Lain, M. & Kendrick, E. Understanding the limitations of lithium-ion batteries at high rates. Journal of Power Sources. Volume 493, 229690 (2021).

Ma, S., et al. Temperature effect and thermal impact in lithium-ion batteries: A review. Progress in Natural Science: Materials International. Volume 28, Issue 6, Pages 653-666 (2018).

Rafael, M., et al. Operando Radiography and Multimodal Analysis of Lithium–Sulfur Pouch Cells—Electrolyte Dependent Morphology Evolution at the Cathode. Adv. Energy Mater. 2103432 (2022).

Joris, J., et al. A comprehensive review of future thermal management systems for battery electrified vehicles. Journal of Energy Storage 31, 101551(2020).
A Microstructure Resolved Multi-Material Model for Silico-Graphite Composite Electrode
Authors: Shah Sameep Rajubhai , Zhao Kejie
Published: August 2024

Silicon (Si) has been considered as the most promising anode material for next-generation high-capacity Li-ion batteries due to its very high theoretical specific capacity. However, the large deformation associated with (de)lithiation and its detrimental consequences like pulverization, loss of electrical contact, and subsequent capacity loss, have long been a roadblock in deploying high-capacity electrodes. Grafting small amounts of Si with graphite has been proven to utilize the higher capacity of silicon and the stability of graphite. The intricacies of interactions between the two active materials and their effect on the overall performance of the composite electrode are still not well known. Here, we present a novel fully coupled multiphysics electrochemical-mechanical model based on 3D microstructure extracted from X-ray tomography scans of Si-C composite electrode. The theoretical framework integrates the large deformation and viscoplastic response of Si, and the two-way coupling between diffusion and interfacial reactions with mechanical stress. The resolution of the pore phase from the silicon and graphite phases allows for the simulation of the Li+ ion kinetics in the composite electrode and influence of the microstructure. The model is employed to study the phenomena of preferential lithiation, crosstalk between active materials, partial utilization due to mechanical influences, and develop strategies to maximize the specific capacity. Lastly, we also explore the potential and avoidance of mechanical damage within active materials and interfacial delamination. The first-of-its-kind 3D microstructure resolved, multi-material model presents a novel tool to simulate the performance of Si-C composite electrode and decode the depth of interactions between the active materials.
Modeling of Lithium-Ion Convection Cell Effects on Reaction Distribution and Different Cathode Active Materials
Authors: Drake Javit , Gao Weiran , Weiss Trent A. , Vargas Ava , Brushett Fikile R.
Published: August 2024

Li-ion batteries (LIBs) could play a substantial role in mitigating climate change if they become more widely adopted in transportation and stationary energy storage applications. Increasing this adoption requires improvement in both power density and energy density. At the cell level, this dual requirement calls for designs and active materials that overcome challenging trade-offs in nominal cell voltage, rate capability, and loaded capacity.

In our previous research,1,2 we simulated that a convection cell with liquid electrolyte flow, using LCO, can overcome the trade-offs by enhancing accessed capacity under high-rate operation. Electrolyte flow achieves this enhancement by effectively addressing both bulk electrolyte mass transfer and thermal limitations. The flow of electrolyte raises cell voltage by promoting a uniform Li+ salt concentration and regulates temperature by removing heat and lowering heat-producing overpotentials.

In our current work, we extend our macrohomogeneous modeling analysis of a Li-ion convection cell to explore the impact of concentration uniformity on charge-transfer reaction distribution and the flexibility of this approach to work with different active materials. Concentration uniformity evens the reaction distribution, facilitating spatially consistent and full utilization of the active material in the electrodes. Additionally, the use of flow enables the cell to maintain rate capability across various electrode thicknesses and areal capacity loadings. At high C rates, a convection cell with flow exhibits significantly higher output capacity than a closed cell without flow. The degree of increase in running voltage and delivered capacity depends on the choice of positive electrode active material—LFP, LCO, NCA, NMC, or LMO.

Finally, simulations of net power density and net energy density account for pumping energy loss across the cell. The improvement in net energy density with flow becomes substantial at high power density.

W. Gao, M.J. Orella, T.J. Carney, Y. Román-Leshkov, J. Drake, F.R. Brushett, J. Electrochem. Soc., 167, 140551 (2020).

W. Gao, J. Drake, F.R. Brushett, J. Electrochem. Soc.
170, 090508 (2023).
Substitution of a Microstructure-Simulation with a Data-Driven Approach for Modelling Mechanical Degradation of Electrodes
Authors: Erhardt Nikolai , Nirschl Hermann
Published: August 2024

One significant aspect of battery aging involves the mechanical degradation of battery electrodes. The intercalation of ions into the active material particles of a lithium-ion battery creates a concentration profile along the radial direction of the active material particle, influenced by transport properties and kinetics. Mechanical stresses arise due to the spatial constraints of intercalated ions, leading to the mechanical degradation of the electrode.

Common cathode materials used in practical applications, such as Lithium Nickel Manganese Cobalt Oxide (NMC) or Lithium Iron Phosphate (LFP), undergo a transition from a lithium-poor phase to a lithium-rich phase during the intercalation process. Along this phase boundary, high mechanical stresses occur due to the inconsistency of the concentration profile, resulting in particle fractures. This can lead to electrical isolation and, consequently, the electrochemical inertization of the active particle material, manifested as a reduced battery capacity on a macroscopic scale.

Simulating these processes poses computational challenges. Given current computational power, accurately simulating a sufficient number of cycles for a microstructure simulation, which describes transport processes within a battery, is computationally prohibitive. Therefore, this study employs data-driven models. To predict radial concentration profiles within the particle, a physics-informed neural network (PINN) proves useful by extending the cost function with the transport equation. Classical neural networks (ANN) are utilized to calculate the electrical voltage of active material particles. These models are trained with results from microstructure simulations to develop a grey-box model, enabling the inclusion of mechanical degradation in the electrode simulation.

Mechanical stresses and degradations are thus investigated under various galvanostatic discharge rates to define an aging-resistant operational window for the battery.
Investigation of Lithium Deposition in Tri-Layer Llzo Garnet Structure As a Function of Cell Cycling Using Nuclear Reaction Analysis Method
Authors: Kanabar Naisargi , Higashiya Seiichiro , Cherniak Daniele , Lanford William , Morgenstern Frederik , Mckinney James , Efstathiadis Haralabos
Published: August 2024

A key challenge of lithium metal batteries is the volumetric expansion of battery after several charging cycles due to the non-uniform deposition of lithium on anode. This leads to lithium dendrite formation compromising battery safety, and poor lifetime. We adapted tri-layer (porous-dense-porous) Al-doped Lithium Lanthanum Zirconium Oxide (LLZO) host (separator) via tape casting. During cycling lithium is deposited in the porous structure preventing dendrite formation. XRD analysis of annealed host structure confirmed presence of cubic phase LLZO which provides higher ionic conductivity. We measured Li distribution on LLZO host structure before and after different cell cycling conditions and investigated the failure mechanism. We performed concentration depth profiles of 7Li and 6Li isotopes by Nuclear Reaction Analysis (NRA) using two different methods: Proton Induced Gamma-ray Emission (PIGE) and Proton Induced Alpha-particle Reaction (Particle-Particle reaction) and compared the results for accuracy. Depth profile of 7Li confirmed 33 at % Li at 0.44µm thickness before cycling which was increased after cycling. The Gaussian distribution of NRA data indicated a uniform Li depth profile in the dense layer. Through electrochemical testing, we measured that Li capacity loss after 5 and 25 charging cycles with 0.1C rate, 1.51mAh and 2.89mAh, respectively, in tri layered LLZO separator.
Evaluating the Influence of SiOx on the Calendar Lifetime of Li Ion Batteries across Varied Temperatures and State of Charge Conditions
Authors: Qayyum Ahmed Abdul , Niehoff Philip , Winter Martin
Published: August 2024

Lithium-ion batteries (LIBs) have a wide range of application in various fields, such as automotive and stationary applications. The incorporation of silicon (Si) in the anode is an attractive strategy to increase energy density and enable fast charging. This is due to the excellent theoretical specific capacity of Si, which exceeds 3000 mAh/g. However, due to the alloying behavior of Si, a significant volume change can be observed by Si based anodes when cycled. In literature the rapid cyclic degradation is related to these volume changes. A practical approach is to use silicon oxide (SiOx) as anode material, which undergoes lower volume changes during cycling but still exhibits a specific capacity >2000 mAh/g. Studies on the cycle life of SiOx-containing cells are frequently published in literature, but calendar life studies are scarce.

Here, the calendar life of two different 1 Ah pouch cell configurations, possessing different anode chemistries, were investigated. One cell contained artificial graphite and 10% SiOx (SiO-cell) while the other cell only used artificial graphite as anode material (G-cell). Both cell configurations were built with an NMC811 cathode. 1 M LiPF6 in EC: EMC (3:7 (wt.)) + 2%wt. VC was used as electrolyte. Temperatures of 20 °C, 40 °C and 60 °C and state of charge (SoC) levels of 20%, 40%, 60%, 80% and 100% were investigated in this study. It has been observed that for 20 °C and 40 °C, the degradation rate of both cell types intensifies when stored at 100% SoC. At 60 °C, however, the capacity fade already starts intensifying drastically at around 60% SoC. The capacity fading during storage experiments of the SiO- cells, depending on the parameters tested, is higher by a factor of around 1.1 to 4.1 than the capacity fading of the G- cells. Interestingly, the capacity fade ratio of the SiO-cell to G-cell is at maximum when cells were stored below 40% SoC at 20 °C. When stored at low SoC, SiOx is the anode active material being lithiated majorly. These findings indicate that SiOx indeed causes stronger calendaric degradation compared to graphite. Hence, in future studies on SiOx based anodes calendaric degradation is an interesting topic to address additionally to cyclic degradation.
Morphology Matters: Surface Properties Inform ALD Deposition and Subsequent Electrochemical Performance in Graphite Substrates
Authors: Herbert-Walters Meghan , Burger Jessica , Lewis Drew , Hughes Barbara K
Published: August 2024

The physical properties of graphite, such as pore volume, shape, and crystallinity; are critical factors in determining the performance of a li-ion cell. These properties are determined by the graphite manufacturing process, which often terminates with a surface treatment process to optimize the morphology. Currently most surface treatments are done using a carbon pitch coating, which involves a high temperature, multi-step process. Coatings using atomic layer deposition (ALD) are, by comparison, less energy intensive and a more customizable approach to target specific physical properties leading to increased cycle life, higher coulombic efficiency, and better rate performance. In this work we will show how ALD coatings are optimized based on the graphite production process and resulting particle morphology. We will demonstrate that these optimized coatings will serve to reduce surface area, prevent graphite exfoliation, and improve li-ion diffusion pathways.
Long-Term Calendar Aging across Commercial Lithium-Ion Cell Chemistries - Part II: Modeling and Early Prediction
Authors: Cui Xiaofan , Stroebl Florian , Lam Vivek , Uppaluri Maitri , Chueh William C. , Onori Simona
Published: August 2024

Lithium-ion (Li-ion) batteries are widely used in applications such as mobility, stationary grid systems, and various consumer and commercial systems. In electric vehicles (EVs), batteries often remain idle, with only about 10% utilization. Moreover, in stationary battery energy storage systems (BESS) designed for peak shaving, resting periods tend to cause more aging effects than the operational cycles. Consequently, quantifying the effect of calendar aging is crucial. However, current calendar aging models are inadequate for accurately modeling and predicting the diverse aging behaviors of commercial Li-ion batteries. In this study, we analyze a new, long-term Li-ion battery calendar aging dataset, which includes eight different commercial battery types. We compare and validate three calendar aging models—semi-empirical, symbolic regression, and Long Short-Term Memory Network (LSTM). We examine the transferability of these models across various commercial cell types, offering insights into their generalizability. Additionally, we introduce a novel trajectory-to-trajectory approach for early prediction of calendar aging lifetime. For the first time, we investigate the model's ability to interpolate and extrapolate aging behavior under different storage temperatures. This research provides practical insights for optimizing battery management strategies in conditions dominated by calendar aging.
(Invited) Advanced Processing Science for Low-Cost, High Energy Density Batteries
Authors: Du Zhijia
Published: August 2024

This project at the DOE Battery Manufacturing R&D Facility (BMF) at Oak Ridge National Laboratory (ORNL) has built research successes on advanced battery processing science and engineering (PSnE), cost reduction, and cell energy and power density improvements. Our goal is to perform the processing science and engineering needed to reduce high-risk, high-payoff technologies to lower risk levels, such that the U.S. industry will consider their integration in future products.

Electron beam curing is demonstrated as a promising method for high speed, low cost and environmentally friendly battery electrode manufacturing. This work reports transfer of this process to pilot scale equipment and evaluation of electrochemical performance in prototype 1.5 Ah pouch cells. Thick NMC composite electrodes with an areal loading of 25 mg cm−2 (∼4 mAh cm−2) are successfully cured at a line speed of 500 feet per minute. This work demonstrates that electron beam curing is a promising method for manufacturing thick battery electrodes at high speeds and low capital/operation cost.
(Invited) The Influence of the Magnetic Field on Ni Thin Film Electrodeposition as an Electrocatalytically Active Material for Hydrogen Evolution Reaction
Authors: Elsharkawy Safya , Kutyła Dawid , Zabinski Piotr
Published: August 2024

Ni thin film were synthesized through the electrodeposition method from three different electrolytes. Furthermore, they were assessed as electrocatalyst for hydrogen evolution reaction (HER) in 1 M NaOH. Herein, various electrodeposition parameters such as pH of the electrolytes, deposition potential, temperature, and the influence of the magnetic field were measured. We made a comparison between the different morphologies and different characteristics depending on the thin film electrodeposition process parameters. Moreover, we have studied the wettability changes of material in dependence from to the composition of the electrolyte and the applied external magnetic field. The deposition process was accomplished by using chronoamperometry technique. The measuring scanning electron microscope, and X-Ray diffraction were used to characterize the surface morphology and the crystalline structures of the fabricated films.