bluuebunny/crossref_metadata_2025 huggingface dataset:
(Invited) Automation of Electrochemical Water Desalination Processes Using Artificial Intelligence Technologies
Authors: Son Moon
Published: December 2024

Electrochemical desalination technologies, including battery electrode deionization and capacitive deionization (CDI), are being actively studied as alternatives to membrane technology due to their relatively low energy consumption. In line with the development of technology, modeling-based research has also been actively conducted to mathematically simulate and automatically control the technology (Donnan models or Lanmuir models). However, despite the complexity of calculations, these numerical models cannot simulate the entire actual operating environment; therefore, multiple assumptions are required. In addition, even in this simplified environment, predictions for specific parameters (effluent pH, etc.) are often very inaccurate.

Therefore, research on big data-based artificial intelligence technology that can overcome the shortcomings of these numerical models has been reported mainly by specific research groups in recent years. First, a study that successfully predicted effluent concentration and pH in CDI using deep learning technology was reported in 2021 yr (i.e., Convolutional Neural Network combined with Long Short-Term Memory), followed by a study based on an ensemble model (i.e., Random Forest) that can overcome the complexity of deep learning models in 2023 yr. In addition, reinforcement learning-based research that can automate processes is also being reported starting in 2022 yr.

Therefore, in this presentation, artificial intelligence technologies that can predict specific output variables of electrochemical desalination technology, quantify the correlation between each input variable (xAI), and ultimately enable process automation will be discussed. The advantages and disadvantages of different artificial intelligence technologies will also be discussed from a practical/technical perspective (i.e., response time, computational cost, etc).
(Invited) Comparison of Tree-Based Model with Deep Learning Model for Predicting Effluent pH and Concentration in an Electrochemical Water Desalination Process
Authors: Ullah Zahid , Yun Nakyeong , Son Moon
Published: December 2024

Capacitive deionization (CDI) is an emerging water treatment technology that offers potential advantages, including reduced environmental impact, simpler operation, and lower energy consumption in certain applications. However, for optimizing the process and ensuring high-quality treated water, accurate prediction of effluent pH and concentration in CDI systems is crucial. Various numerical models developed for simulating CDI performance often struggle to capture the complexities of real-world operating conditions. Recently, artificial intelligence (AI) techniques have been widely employed to overcome these limitations by their capability to model complex nonlinear relationships and adaptively respond to changing conditions. Therefore, this study presents a comprehensive comparison of tree-based models and a deep learning model in predicting the effluent pH and concentration in a CDI system. The study developed and evaluated the performance of a steady random forest (SRF) model, a dynamic random forest (DRF) model, and a convolutional neural network-long short-term memory (CNN-LSTM) model using the same dataset. The models were trained and tested on tabular data from constant current (CC) and constant voltage (CV) MCDI operations.

The results showed that the tree-based models and the CNN-LSTM model achieved similar prediction accuracy when used on the operation mode they were trained on, with R2 values exceeding 0.98 for both effluent pH and concentration. However, in generalization tests across different operation modes, the performance of the SRF model without binary features significantly deteriorated (R2 < 0.115). To address this, binary features were incorporated to distinguish between the CC and CV operating modes, which substantially improved the SRF model's generalization ability, with R2 values (model R2 > 0.5) comparable to the CNN-LSTM model.

Feature importance analysis revealed that voltage, current, and influent pH were the most influential factors in predicting both effluent pH and concentration, aligning with the characteristics of the CDI process. Notably, the tree-based models demonstrated a significant advantage in computational efficiency, requiring over 100 times less computation time per iteration than the CNN-LSTM model.

These findings suggest that tree-based models, particularly the SRF model with binary features, can be a viable and computationally efficient alternative to deep learning models for modeling and optimizing CDI processes. The approach of incorporating binary features to enhance the generalization ability of tree-based models is a practical and cost-effective solution that can be applied to other complex engineering problems. Further research in this area could help reduce modeling complexity and computational costs, offering more straightforward computational modeling methods for CDI processes.
(Invited) Enhancing PET Plastic Circularity and Decarbonization through Process Electrification and Intensification
Authors: Bunke Samantha , Yu Hyejin , Cha Hyun Gil , Tarpeh William Abraham , Kang Donghyeon
Published: December 2024

Polyethylene terephthalate (PET) production generates roughly 3.2 kg of CO2 per kg of resin.[1] As the most produced plastic globally (82 million metric tons per year), PET contributes to 272 million metric tons of CO2 equivalent annually. Chemical depolymerization of PET into its monomers is a key strategy for achieving plastic circularity. While various methods have emerged in recent decades, current chemical recycling processes are often uneconomical and do not significantly reduce greenhouse gas emissions. For instance, catalytic depolymerization using base catalysts (e.g., NaOH) in alcohols is being commercialized, but NaOH is neither a superior catalyst nor cost-effective due to its production and delivery expenses. Consequently, the high cost leads to PET waste ending up in landfills or incinerators, perpetuating low circularity and high CO2 emissions.[2,3]

To address these limitations in chemical PET depolymerization, our team has developed an innovative electrochemical system for efficient and cost-effective PET recycling. This system selectively decomposes mixed plastic waste at room temperature and ambient pressure, achieving rapid depolymerization into virgin-quality PET monomers. The process is intensified through electrification, significantly reducing overall costs and CO2 emissions while promoting PET circularity. By incorporating renewable electricity, the system can utilize excess energy generated during off-peak hours. Additionally, the process co-produces valuable chemicals like hydrogen and hydrochloric acid (HCl), ultimately making PET recycling economically viable. We are committed to further maturing this electrochemical PET depolymerization technology with the goal of commercialization.

References

[1] Gracida-Alvarez, U. R.; Xu, H.; Benavides, P. T.; Wang, M.; Hawkins, T. R., Circular Economy Sustainability Analysis Framework for Plastics: Application for Poly(ethylene Terephthalate) (PET). ACS Sustainable Chemistry & Engineering
2023, 11, (2), 514-524.

[2] Nicholson, S. R.; Rorrer, N. A.; Carpenter, A. C.; Beckham, G. T., Manufacturing energy and greenhouse gas emissions associated with plastics consumption. Joule
2021, 5, (3), 673-686.

[3] Martín, A. J.; Mondelli, C.; Jaydev, S. D.; Pérez-Ramírez, J., Catalytic processing of plastic waste on the rise. Chem
2021, 7, (6), 1487-1533.

Figure 1
Coatings Based on Single-Ion and Intrinsically Conducting Polymers for High-Voltage Cathode Materials
Authors: Guerrero Mejía Luis Miguel , Ruiz-Zepeda Francisco , Tchernychova Elena , Dominko Robert
Published: December 2024

One of the main challenges presented by cathodic materials for lithium batteries is to ensure that capacity is maintained during cycling. The Ni-rich cathode LiNi0.8Mn0.1Co0.1O2 (NMC811) is considered a promising material due to its high energy density. However, this material presents a rapid decay in its capacity during the first charging and discharging cycles due to the direct contact of the NMC811 particles with the electrolyte. In this work, we have investigated the development and the effects on the electrochemical properties of a polymer coating based on a lithium single-ion conductor together with a conjugated polymer that prevents direct contact between the NMC811 particles and the electrolyte. These materials are used to create a homogeneous coating that acts as a channel for the transport of lithium only between the two interphases. It also serves as an electronic conductor that promotes good contact between the NMC811 particles, the carbon black, and the current collector. Furthermore, there are no reports on the use of single-ion conducting polymers as coatings for NMC materials, only reports on intrinsically conducting polymers to improve the electronic conductivity between cathodic components and capacity retention. In addition, these coatings act as an artificial cathode-electrolyte interphase to prevent unwanted reactions. X-ray photoelectron spectroscopy (XPS) was carried out to investigate the presence and evolution of these coating compounds during cycling. In addition, SEM and TEM were performed to observe the surface morphology of the particles and determine the thickness of the coating. Finally, electrochemical impedance spectroscopy (EIS) was used to evaluate the effects of the coating compounds on the charging and discharging processes as well as their stability during cycling. This study shows that the development of modulated coatings can provide an innovative approach to obtaining Ni-rich cathode materials with a longer lifespan for lithium batteries.

L.M. Guerrero Mejía et al. manuscript in preparation.
Enhancing the Energy Density and Cycle Life of Li/Sulfurized Polyacrylonitrile (SPAN) Batteries
Authors: Phan An , LE Phung M-L , Wang Chunsheng
Published: December 2024

Li/sulfurized polyacrylonitrile (Li/SPAN) batteries are garnering attention for their potential in sustainable energy storage with notable advantages such as a high theoretical energy density exceeding 1000 Wh kg-1, surpassing the 750 Wh kg-1 of Li/NMC811, and being free of transition metals. The absence of transition metals addresses concerns related to their cost, scarcity, uneven distribution, and potential toxicity. However, current Li/SPAN batteries have yet to realize their full potential in terms of energy density and cycle life. This shortfall can be attributed to a lack of comprehensive understanding across various system levels, resulting in a dearth of well-directed research efforts.

In this work, we conduct a thorough study of the energy density and cycle life of practical Li/SPAN cells using internally developed models. Our analysis revealed refreshed perspectives from the common consensus among the Li/SPAN battery community. Concerning energy density, we find that this output is notably influenced by SPAN voltage, electrolyte weight, and inactive weights. In addition to the conventional method of enhancing SPAN specific capacity, these parameters present fresh opportunities to boost the energy density of Li/SPAN batteries. Details about potential executive strategies and practical viability regarding each parameter are also discussed.

Regarding cycle life, while the Coulombic efficiency of Li plating/stripping (Li CE) is widely recognized as a critical factor, our analysis reveals that its impact primarily lies in regulating the consumption of the electrolyte rather than that of Li metal. Therefore, controlling the chemistry of side reactions, represented by the average equivalent molecular weight (i.e., molecular weight over number of exchanged electron) and electrolyte density, emerges as a complementary approach to improve cycle life. Overall, our findings suggest that transitioning from heavy hydrofluoroether-based localized high-concentration electrolytes (LHCEs) to lightweight alkyl ether-based weakly-solvating electrolytes is beneficial for advancing Li/SPAN batteries, both in terms of energy density and cycle life.
The Impact of Lithium Anode Interface on Capacity Fade in Polymer Electrolyte-Based Solid-State Batteries
Authors: Owensby Kyra D'Yana , Ock Jiyoung , Sahore Ritu , Meyer Harry M , Lin Yan-Ru , Tsai Wan-Yu , Chen Xi Chelsea
Published: December 2024

This study investigates the Li stripping/plating morphology and failure mechanisms in full cells consisting of a solid polymer electrolyte (SPE) with two commercial Li anodes, Li chip and Li foil. The primary identified failure mechanism in the SPE is capacity fade, regardless of Li manufacturer or polymer thickness. While the cathode's role in capacity fade is evident, the Li anode significantly influences cycling performance, with Li foil cells cycling 50% longer than Li chip cells, a statistical difference. Postmortem scanning electron microscopy and X-ray photoelectron microscopy results attribute the Li Chip's faster capacity fade to a loss of contact and continuous growth of the solid electrolyte interface (SEI). Conversely, Li foil maintains consistent contact with the solid polymer, displaying a thin and stable SEI. Additionally, failure mechanisms between a gel electrolyte in previous work and the dry solid polymer electrolyte is compared.
(Invited) Thin Organic Crystal Films of Single Li+ Ion Conductors for Lithium-Ion Batteries
Authors: Byon Hye Ryung
Published: December 2024

Despite the significant attention given to polymeric electrolytes in lithium (Li)-ion batteries, their practical use has been hindered by low ionic conductivity. The sluggish Li+ transport is primarily attributed to the segmental motion of the polymer backbone. Thus, it is crucial to develop rigid and well-defined crystal structures. Covalent organic frameworks (COFs) present a promising solution as electrolytes, composed of well-ordered and stacked layers encompassing ionic channels. By tethering anionic substitutes associated Li+ to the edges of the channels, the COF becomes the Li+ ion conductors. Typically, a COF electrolyte is prepared using powdery particles, and subsequent pelletization forms a thick film with a thickness exceeding 100 µm. Unfortunately, this electrolyte results in significant roughness and tortuosity, leading to a high contact resistance of over 1 kΩ and disrupting the ionic channel.

To address this issue, we developed a one-pot synthetic method to create a uniform COF film with approximately 20 µm thickness and a roughness of ~4 nm. The introduction of the sulfonate group resulted in ~2 nm pore size, and the COF layers are stacked through pi-pi interactions with high crystallinity. We varied the thickness of the COF film from 20 to 60 µm and compared their crystallinity and ionic conductivity. The result showed that both crystallinity and logarithmical ionic conductivity increased as the film thickness decreased. In the COF film with a thickness of 20 µm, the ionic conductivity reached around 10-4 S cm-1 at 30 oC. The interfacial resistance at metallic Li was approximately 250 Ω, eight times lower than that of the pellet-type COF. These films exhibited stable cyclability in symmetric Li cells over 1000 hours at room temperatures. Additionally, Li|LiFePO4 cells with the COF electrolyte demonstrated 86% capacity retention over 300 cycles and a 99.95% Coulombic efficiency at a 0.5 C rate.
Highly Reversible Lithium Deposition and Stripping Under Practical Conditions through Improved Wettability of Polyolefin Separator to Highly Concentrated Electrolytes
Authors: Ugata Yosuke , Yabuuchi Naoaki
Published: December 2024

Lithium metal is regarded as a promising negative electrode material for rechargeable batteries, but several challenges such as the dendritic growth of lithium metal and side reactions between lithium metal and electrolyte hinder the practical application of lithium metal batteries (LMBs). In recent years, several research groups reported that highly concentrated electrolytes (HCEs) are effective in suppressing side reactions and improving the electrode reversibility of lithium metal.[1] However, the poor wettability of conventional polyolefin separators toward HCEs remains a critical issue to be addressed. Although porous glass fiber filters are often used as separators for HCEs, lithium dendrites easily penetrate the separator during repeated lithium deposition/stripping at areal capacities over 1 mA h cm−2, leading to an internal short circuit. Here, we present the effective strategies to solve the electrolyte wettability issue and to achieve stable cycling of LMBs under practical conditions. The use of a functional polyolefin separator coated on both sides with an aramid layer improves the electrolyte wettability because polar functional groups provide a better affinity between the polyolefin separator and HCE.[2] The combined use of HCE (5 mol dm-3 LiN(SO2F)2 in 1,2-dimethoxyetahne) and aramid-coated polyolefin separator increases the reversible lithium deposition capacity up to >10 mA h cm−2 and results in stable lithium deposition/stripping cycling with high Coulombic efficiency of ~99% at practical areal capacity of 4 mA h cm−2. From these results, the possibility of developing practical high-energy LMBs with HCEs will be discussed.

References

[1] Yosuke Ugata and Naoaki Yabuuchi, Trends in Chemistry, 5, 672–683 (2023).

[2] Yosuke Ugata, Chihaya Motoki, Satoshi Nishikawa, and Naoaki Yabuuchi, Energy Advances, 2, 503-507 (2023).
Rationally Designed Li-Ag Alloy with in-Situ Formed Solid Electrolyteinterphase for All-Solid-State Lithium Batteries
Authors: Oh Myungkeun , Park Ye-Eun , Sim Hui-Tae , Kim Hyojin , Cho Yun-Sun , PARK Seongjin , Kim Dong-Won
Published: December 2024

Sulfide-based all-solid-state lithium metal batteries (ASSLBs) have attracted enormous attention as promising energy storage device due to their high energy density and enhanced safety. However, the combination of lithium metal anode and sulfide electrolytes leads to performance degradation due to the lithium dendrite growth and side reactions of lithium metal with solid electrolyte. In order to address these issues, many studies have been conducted to control the interface by modification of lithium metal (e.g. surface coating, Li-based metal alloy, Li with buffer layer etc.). In this work, the Ag-based Li alloy with favorable solid electrolyte interphase (SEI) was prepared by electrodeposition and applied to the ASSLB as an anode. The electrochemically formed SEI layer on Li-Ag alloy was mainly consisted of LiF and Li2O with high mechanical strength, and Li3N with high ionic conductivity, which suppressed the lithium dendrite and short-circuit of the cell. The symmetric cell employing Li-Ag alloy achieved a critical current density of 1.6 mA cm-2 and maintained stable cycling over 2000 h at current density of 0.6 mA cm-2. Consequently, the all-solid-state lithium cell assembled with Li-Ag alloy anode with SEI, Li6PS5Cl solid electrolyte and LiNi0.78Co0.10Mn0.12O2 cathode delivered a high discharge capacity of 185 mAh g-1 and exhibited good cycling performance in terms of cycling stability and rate capability at 30 oC
Understanding Electrolyte Stability and Instability in Lithium-Ion Batteries with Nickel-Rich Cathodes
Authors: Terreblanche Jason S , Luo Tongjun , Piper Louis F. , Dose Wesley M.
Published: December 2024

Developing electrolyte solutions that are stable at the electrode-electrolyte interfaces is critically important to enable high performance lithium-ion batteries. The discovery in the early 1990s that a mixture of ethylene carbonate (EC) and alkyl carbonate(s) could passivate graphite led to a step change in the cell energy density,1,2 and modern batteries still retain this skeleton electrolyte formulation and graphite anode combination. However, as the battery industry shifts to nickel-rich layered oxide cathodes for lower cost and higher energy density cells,3,4 an incompatibility between EC-containing electrolytes and the cathode is starting to be revealed. This is driving research efforts to, firstly, understand the chemical reactions at the nickel-rich cathode-electrolyte interface5-9 and, secondly, explore new EC-free electrolyte solutions.10-13

Here we examine the dominant degradation phenomena in nickel-rich NMC/graphite full cells with EC-containing and EC-free electrolytes. We combine a range of methods including cell cycling, operando pressure measurements, OEMS, XPS, XRF, and solution NMR to understand the behaviour of the two electrolyte systems throughout the full cell. The results of these studies will be discussed in conjunction with their implications for further development of compatible electrolytes for advanced lithium-ion battery chemistries.

References:

Xu, Nat. Energy, 2021, 6, 763.

Fujimoto, N. Yoshinaga, K. Ueno, N. Furukawa, T. Nohma, M. Takahashi, Japanese patent, 3,229,635, 1991.

Xu, X. Liu, A. Daali, R. Amine, Z. Chen, K. Amine, Adv. Funct. Mater., 2020, 30, 2004748

Li, E.M. Erickson, A. Manthiram, Nat. Energy, 2020, 5, 26.

Wandt, A.T.S. Freiberg, A. Ogrodnik, H.A. Gasteiger, Mater. Today, 2018, 21, 825.

T.S. Freiberg, M.K. Roos, J. Wandt, R. de Vivie-Riedle, H.A. Gasteiger, J. Phys. Chem. A, 2018, 122, 8828.

Zhang, Y. Katayama, R. Tatara, L. Giordano, Y. Yu, D. Fraggedakis, J.G. Sun, F. Maglia, R. Jung, M.Z. Bazant, Y. Shao-Horn, Energy Environ. Sci. 2020, 13, 183.

M. Dose, I. Temprano, J.P. Allen, E. Bjorklund, C.A. O'Keefe, W. Li, B.L. Mehdi, R.S. Weatherup, M.F.L. De Volder, C.P. Grey, ACS Appl. Mater. Interfaces, 2022, 14, 13206.

M. Dose, W. Li, I. Temprano, C.A. O’Keefe, B.L. Mehdi, M.F.L. De Volder, C.P. Grey, ACS Energy Lett., 2022, 7, 3524.

Xia, R. Petibon, D. Xiong, L. Ma, J.R. Dahn, J. Power Sources, 2016, 328, 124.

Petibon, J. Xia, L. Ma, M.K.G. Bauer, K.J. Nelson, J.R. Dahn, J. Electrochem. Soc. 2016, 163, A2571.

Li, A. Dolocan, J. Li, Q. Xie, A. Manthiram, Adv. Energy Mater., 2019, 9, 1901152.

Pan, Z. Cui, M. Yi, Q. Xie, A. Manthiram, Adv. Energy Mater., 2022, 12, 2103806.

Figure 1
Enhancing Performance of Lithium Sulfur Batteries with Electrode-Electrolyte Interphase Engineering
Authors: Chen Hsun-Yi , Rusly Cindy
Published: December 2024

Batteries with high energy density are critical for the clean energy transition of human society. Lithium sulfur (Li-S) batteries with a high theoretical energy capacity is promising for applications such as electric vehicles. However, the commercialization obstacle of Li-S batteries lies on the shuttle effects of dissolved sulfur intermediates and formation of Li dendrite. In this work, we focus on engineering the electrode-electrolyte interphase with functionalized interlayers for enhanced performance of Li-S batteries. In particular, an amide-functionalized protection layer and a cellulose-based separator are employed, respectively. We discovered multifunctionality of these interlayers, including dendrite inhibition and shuttle effect suppression. A more conductive solid-electrolyte interphase (SEI) with high stability is demonstrated to form when these interlayers are used, via in-situ X-ray diffraction and impedance spectroscopy investigation. Our work paved a way to engineer electrode-electrolyte interphases in Li metal batteries without electrolyte additives.
Electrochemical Performance of LiFePO4 Cathode with Dispersed Ion-Conductive Material
Authors: Kumchompoo Jaturon , Lee Jyh-Tsung , Li Chia-Chen
Published: December 2024

Lithium-ion batteries (LIBs) with LiFePO4 (LFP) cathodes have gained significant commercial traction due to their high energy density, excellent rate capabilities, and cost-effectiveness. However, meeting the demand for high-power and high-energy-density storage presents challenges. This study introduces garnet Li6.4La3Zr1.4Ta0.6O12 (LLZTO) integration at nano and micro scales in a well-dispersed suspension, enhancing lithium-ion transport without compromising mechanical strength. LFP-nano-LLZTO-dispersant exhibits improved physical and electrical performance, attributed to smooth surfaces influenced by dispersant addition. Assembly of Li-cells resulted in notable capacity retention for LFP-nano-LLZTO-dispersant, increasing from 79.1% to 94.5% at a 0.5 C rate after 300 cycles, with a reversible capacity of 72.1 mA h g−1. Furthermore, the incorporation of LFP-micro/LLZTO-dispersant demonstrated enhanced electrochemical performance, with stable high-capacity retention rising from 89.6% to 98.6% and a reversible capacity of 136.4 mA h g−1 after 300 cycles at 0.5 C. This improvement is attributed to the use of micro-sized garnet LLZTO particles and suitable dispersant, which prevent cathode cracking, reduce electrolyte degradation into too thick formation of cathode electrode interface (CEI) layer, and enhance LFP electrode cycle stability.

Figure 1
Synthesis and Characterization of Advanced Thin-Film Metallic Glass Anodes for Lithium Metal Batteries
Authors: Howard Jerry , Carlson Krista , Chidambaram Dev
Published: December 2024

Instability of the solid-electrolyte interphase (SEI) formed on the surface of the anode is a major cause of capacity degradation in Li-ion and Li metal batteries. High-capacity anode materials which form a stable SEI are desirable for improving the lifetime performance of batteries made using these technologies. One such class of materials that has been suggested are Si-based metallic glasses. Si alloys have a high theoretical capacity, and the amorphous structure has been shown to improve capacity. The SEI layer that forms on these anodes is thin and highly stable. In this research, a genetic algorithm method was used to locate optimal compositions of Si-based metallic glasses for use in Li metal batteries. Sputtering was then employed as a high-throughput, combinatorial method to produce a library of compositions for initial characterization and electrochemical testing. Nanostructured metallic glass anodes with improved capacity and high electrochemically active surface area were then synthesized. The capacity and stability of these anode materials were tested in Li metal batteries. After battery testing, the SEI formed on the anode was characterized to understand its chemistry and structure.

This work is funded by NASA under grant 80NSSC19M0152. JRH is funded as a fellow under the NSF GRFP.
(Invited) Controlled Large-Area Lithium Deposition to Reduce Swelling of High-Energy Lithium Metal Pouch Cells in Liquid Electrolytes
Authors: Xiao Jie
Published: December 2024

Lithium (Li) metal battery technology, renowned for its high energy density, faces practical challenges, particularly concerning large volume change and cell swelling. Despite the profound impact of external pressure on cell performance, there is a notable gap in research regarding the interplay between external pressure and electroplating behaviors of Li+ in large-format pouch cells. Here we delve into the impact of externally applied pressure on electroplating and stripping of Li in 350 Wh/kg pouch cells. Employing a hybrid design, we monitor and quantify self-generated pressures, correlating them with observed charge-discharge processes. A two-stage cycling process is proposed, revealing controlled pouch cell swelling of less than 10%, comparable to state-of-the-art Li-ion batteries. The pressure distribution across the cell surface unveils a complex Li+ detour behavior during electroplating, highlighting the need for innovative strategies to address uneven Li plating and enhance Li metal battery technology.
Thermal Pyrolysis of Ammonium Fluoride Induced Multilayered Protection for Longevity of Lithium Metal Batteries
Authors: Taklu Bereket Woldegbreal , Su Wei-Nien , Hwang Bing Joe
Published: December 2024

Utilizing the "Holy Grail" lithium metal anode is crucial for attaining high energy density1. Nevertheless, employing a lithium metal as anode faces practical challenges due to thermodynamic instability and dendrite growth1-2. An artificial stabilization of lithium metal mainly employed to mitigate the electrolyte decomposition, dead lithium metal formation and dendrite growth3. A facile and cost effective gas treatment of lithium metal was carried out using thermal pyrolysis of NH4F salt to generate HF(g) and NH3(g). An exposure of lithium metal to the generated gas induces a spontaneous reaction that forms multilayer protection with multiple solid electrolyte interface (SEI) components, such as LiF, Li3N, Li2NH, LiNH2, and LiH from a single salt. The formation energy (ΔEf) using DFT-D3 calculations coupled with depth profile XPS and XRD measurements proven the formation of these reaction products. An operando optical microscope (Operando OM) observation on plating/stripping phenomena in symmetric cells under conventional carbonate electrolyte (1 M LiPF6 EC/DEC (1:1 v/v)) operated at 3 and 5 mA cm−2 current density demonstrate the advantage of protection layer on suppression of lithium dendrite. Furthermore, the artificial multilayer protection on lithium sustains stable lithium reversibility and overpotential under varied cell configuration both symmetric cell, Li||Li and half-cells, under Li||Cu and Li||MCMB systems. We demonstrate that the desirable protective layer with LiFePO4 (LFP) showed a capacity retention (CR) of 90.6% at 0.5 mA cm−2 after 280 cycles, and LiNi0.5Mn0.3Co0.2O2 (NCM523) showed 58.7% at 3 mAcm−2 after 410 cycles. Formulating the multi-layered protection, with the simultaneous formation of multiple SEI components in a facile and cost-effective approach from NH4F as a single salt, making the system competent.

References

Taklu, B. W.; Su, W.-N.; Chiou, J.-C.; Chang, C.-Y.; Nikodimos, Y.; Lakshmanan, K.; Hagos, T. M.; Serbessa, G. G.; Desta, G. B.; Tekaligne, T. M.; Ahmed, S. A.; Yang, S.-C.; Wu, S.-H.; Hwang, B. J., Mechanistic Study on Artificial Stabilization of Lithium Metal Anode via Thermal Pyrolysis of Ammonium Fluoride in Lithium Metal Batteries. ACS Applied Materials & Interfaces
2024,
16 (14), 17422-17431.

Moon, S.; Park, H.; Yoon, G.; Lee, M. H.; Park, K.-Y.; Kang, K., Simple and effective gas-phase doping for lithium metal protection in lithium metal batteries. Chemistry of Materials
2017,
29 (21), 9182-9191.

Taklu, B. W.; Nikodimos, Y.; Bezabh, H. K.; Lakshmanan, K.; Hagos, T. M.; Nigatu, T. A.; Merso, S. K.; Sung, H.-Y.; Yang, S.-C.; Wu, S.-H., Air-stable iodized-oxychloride argyrodite sulfide and anionic swap on the practical potential window for all-solid-state lithium-metal batteries. Nano Energy
2023,
112, 108471.

Figure 1. Schematic illustration for the formation of an artificial multilayered protection via gas treatment and its effect on lithium plating.

Figure 1
Decoupling the Capacity Fading in Ni-Rich Layered Materials during High-Temperature Cycling in the Full-Cell System
Authors: Kim Minji , Lee Wontae , Yoon Won-Sub
Published: December 2024

The performance of commercial lithium-ion batteries (LIBs) tends to degrade over time owing to the deterioration of key components, including cathode, anode, and electrolyte. To enhance performance, it is crucial to gain insights into the actual deterioration state of each element. Here, the high-temperature deterioration of a Ni-rich layered cathode is investigated, which is widely used in electric vehicles. In the refresh process after a prolonged cycle, a significant recovery of the lattice structure predominantly occurs in the discharge region. This pseudo-deterioration of the Ni-rich cathode within the full-cell system is mainly due to the consumption of the Li-ion forming the solid electrolyte interphase layer at the graphite anode during the cycle. Moreover, irreversible deteriorations that are not restored through the refresh process are observed in both charge and discharge regions. Structure analyses reveal that the long-term cycling at the high temperature leads to a mixed fading of charge and discharge via various deterioration such as the formation of NiO-like rock salt phase on the cathode surface and increased cation disorder in the bulk. These findings deepen the understanding of the deterioration behavior of Ni-rich cathodes in full-cell systems, providing insights for enhancing the performance of high-temperature cycling.

Figure 1
(Invited) High-Performance Ni-Rich Cathodes through Microstructure- and Surface-Modification for Electric Vehicle Batteries
Authors: Sun Yang-Kook
Published: December 2024

The surge in battery production has prompted the diversification of battery chemistries to strengthen the resilience of battery supply chains. Among battery components, cathodes are considered defining features because they primarily determine both battery cost and performance. Among the existing cathode materials available in LIBs, Ni-rich layered lithium transition-metal oxides, NCM(A) are the most practical candidates for EVs and have been studied extensively in the past two decades because of their high reversible capacity and good rate capability. As the Ni content approaches more than 90%, however, it is challenging to realize high-energy Ni-rich NCM(A) cathodes without sacrificing durability. Capacity fading of Ni-rich NCM(A) cathodes largely originates from microcracking which exposes a large portion of the cathode interior to deleterious electrolyte attack. To suppress the development of microcracks on cathode materials, Ni-rich cathode materials should guarantee mechanical stability even in highly charged states. Furthermore, various side reactions at the cathode–electrolyte interface contribute to the rapid capacity fading of the Ni-rich cathode materials.

In this presentation, Ni-rich layered cathodes through microstructure- and surface-modification are presented. We improved the cycling stability of a Ni-rich NCMA cathode using a combination strategy involving microstructural refinement via high valence dopant and surface modification by F coating. The introduction of high valence dopant into the NCMA cathode, refines, elongates, and radially aligns its bulky primary particles by impeding the coarsening of primary particles of hydroxide precursor, thereby preserving the microstructure until the cathode attains optimal crystal structure. Furthermore, F coating promotes the formation of a stable LiF layer by reacting with the residual lithium on the surface of the cathode material. The preformed LiF on the cathode surface impedes the decomposition of salts, preventing their by-products from triggering the autocatalytic side reactions at the electrolyte–cathode interface and thereby suppressing gas generation during cycling. The combination of the elimination of the residual lithium, microstructure refining, and formation of a LiF layer on the near-surface can significantly extend the cycle life of Ni-rich cathodes to simultaneously satisfy the energy density, durability and safety requirements of next-generation batteries for practical applications.
Nanoscale Sulfide Coatings for Addressing the Issues of Nickel-Rich Metal Oxide Cathodes
Authors: Meng Xiangbo , Liu Yuzi , Xiao Xianghui , Zhou Hua , Velasquez Kevin , K C Navin , Singh Meetesh
Published: December 2024

High-nickel (Ni) metal oxides are among the most promising cathodes for high-energy rechargeable batteries, featuring their higher capacity and lower cost than those of the commercialized LiCoO2 cathodes. Among them, Ni-rich lithium nickel manganese cobalt oxides, LiNixMnyCozO2 (NMCs, x ≥ 0.6, x + y + z = 1) are particularly attractive, ascribed to their further improvement in capacity and cost. Unfortunately, Ni-rich NMCs suffer from a series of inherent issues related to performance and safety, which become more and more challenging with increasing Ni contents. To address these issues, a variety of strategies have been employed, such as element doping, surface coating, and new electrolytes and additives. Using atomic layer deposition (ALD), recently, we coated Ni-rich NMC cathodes with sulfide coatings. For the first time, consequently, we found that sulfides are a class of coating materials having special protection effects on NMCs but have not been explored previously. Our recent and on-going studies revealed that sulfide coatings could be converted into sulfites and/or sulfates.1 Such a conversion is favorable for protecting electrolytes from oxidation. Furthermore, the resultant sulfites/sulfates enable better ionic conductivity while fulfill other functions including improving mechanical integrity, mitigating undesirable interface reactions, and inhibiting structural degradation. Additionally, ALD as a coating method provides many benefits, such as conformal and uniform coating coverage, low process temperature, and accurate coating thickness.2-4 Thus, our studies not only opened a new area for surface coating of electrodes but also demonstrated ALD being very beneficial for pursuing high-performance NMCs.

Wang, X.; Cai, J.; Ren, Y.; Benamara, M.; Zhou, X.; Li, Y.; Chen, Z.; Zhou, H.; Xiao, X.; Liu, Y.; Meng, X., High-performance LiNi0.8Mn0.1Co0.1O2 cathode by nanoscale lithium sulfide coating via atomic layer deposition. Journal of Energy Chemistry
2022,
69, 531-540.

Meng, X.; Yang, X. Q.; Sun, X. L., Emerging applications of atomic layer deposition for lithium-ion battery studies. Adv. Mater.
2012,
24 (27), 3589-3615.

Meng, X., Atomic layer deposition of solid-state electrolytes for next-generation lithium-ion batteries and beyond: Opportunities and challenges. Energy Storage Materials
2020,
30, 296-328.

Meng, X., Atomic and molecular layer deposition in pursuing better batteries. J. Mater. Res.
2021,
36, 2-25.
(Invited) Prediction of Electrode-Electrolyte Degradation through First-Principles and Data-Driven Reaction Networks
Authors: Persson Kristin A.
Published: December 2024

Despite decades of work, there is still considerable uncertainty regarding the major components of the solid-electrolyte interface (SEI) and its dynamic formation mechanism as a function of electrolyte and anode composition. Here we present a our data-driven first-principles framework using a combination of high-throughput calculations, reaction networks, machine learning and microkinetic modeling. Our automated methodology is based on a systematic generation of relevant species using a general fragmentation/recombination procedure which provides the basis for a vast thermodynamic reaction landscape, calculated with density functional theory. We explore this landscape using stochastic methods and shortest pathfinding algorithms, which yield the most likely reaction pathways which are then refined with transition state calculations and kinetic information. The results of the framework show promise in being able to automatically recover previous insights on single reaction pathways, as well as successfully predicting the early dynamics and competitive nature of the SEI formation. As examples, we present i) formation mechanisms of LEMC as compared to LEDC and ii) recover the Peled-like separation of the SEI into inorganic and organic domains resulting from rich reactive competition. By conducting accelerated simulations at elevated temperature, we track SEI evolution, confirming the postulated reduction of lithium ethylene monocarbonate to dilithium ethylene monocarbonate and hydrogen gas. Relevant for future reaction networks, we use first-principles methods to uncover new mechanistic understanding of decomposition pathways for LiPF6 and EC, the latter under oxidative conditions. These findings furnish fundamental insights into the dynamics of SEI formation and demonstrate a path forward toward a predictive understanding of electrochemical passivation.
Deep Learning Analysis of Solid Electrolyte Interface Microstructures in Lithium-Ion Batteries
Authors: Borshon Ishraque Zaman , Jabbari Vahid , Kingston Todd A. , Mashayek Farzad , Shahbazian-Yassar Reza , Yurkiv Vitaliy
Published: December 2024

Understanding the structure of the solid-electrolyte interface (SEI) in lithium-ion batteries (LIBs) is crucial for improving battery performance and safety. This study introduces a novel deep learning (DL) framework to analyze transmission electron microscopy (TEM) images of SEI, specifically focusing on identifying different types of grains and grain boundaries. Utilizing advanced machine learning (ML) algorithms, including deep convolutional neural networks, our approach enables the accurate segmentation and classification of complex microstructural features in SEI layers based on the experimental high-resolution TEM images.

The DL model was trained on a comprehensive dataset of simulated SEI TEM images, generated through density functional theory (DFT) calculations and cryogenic high-resolution TEM (cryo-HRTEM) imaging. These simulations provided a diverse range of SEI microstructures, reflecting the polycrystalline nature of real battery interfaces. The model's ability to discern between various grains and grain boundaries in the SEI was fine-tuned through this training process, ensuring high accuracy and reliability in subsequent experimental image analyses.

Experimental validation was performed using cryo-HRTEM images of lithium-based batteries' SEI layers. The results demonstrated the model's proficiency in identifying and classifying different grain and grain boundary types, with significant accuracy. Particularly, the model successfully mapped the distribution of Li2O, LiF, and Li2CO3 components within the SEI, as well as adeptly identified the crystallographic orientations of grains, such as the LiF(111)/Li2CO3(200) and Li2O(111)/Li2CO3(111) boundaries, unraveling the complex structure of the SEI at a nanoscopic level. Consequently, these structural features were correlated with ion diffusion pathways and potential sites for lithium dendrite formation – a detrimental phenomenon in LIBs leading to thermal runaway.

This DL-based analysis provides new insights into the microscopic mechanisms governing ion transport and degradation in battery SEI layers. By offering a detailed characterization of grain and grain boundary structures, our method sets the groundwork for targeted improvements in battery design and materials selection. The study underscores the potential of integrating ML with advanced microscopy techniques to unravel the complex interplays within battery materials, propelling the field towards more resilient and efficient energy storage solutions.

VY and TAK gratefully acknowledge financial support from the Department of Defense (DoD) Office of Naval Research (ONR) through the Defense Established Program to Stimulate Competitive Research (DEPSCoR).
Investigation of Sodium Leaching into Electrolytes during Electrochemical Testing
Authors: Kerber Brian M , Garg Shipra , Hennek Matthew , Usrey Monica Lee , Sriramulu Suresh
Published: December 2024

Many mechanisms and degradation pathways have been identified in the literature that result in leaching of transition metals from the cathode, resulting in loss of capacity during cycle life testing due to fewer sites for lithium intercalation into the cathode during discharge1. But electrode formulations contain more components than just active material- there are also binders, conductive carbon, other additives, and coatings. The extent to which these other components can break down and cause electrode degradation and any subsequent effects on cell performance is not well known.

This poster explores the chemical and electrochemical influences on extraction of materials from electrodes, such as sodium, that may be harmful to battery performance. Post mortem analyses of electrolytes after electrochemical testing in multilayer pouch cells have found sodium content in the range of 200-300 ppm, well above typical specifications for battery-grade products (1-10 ppm). The most probable source of sodium in the battery is sodium carboxymethyl cellulose (CMC), often used in graphite anodes as a rheology modifier during production. In this study, the leachability of sodium from CMC in various extraction solutions was investigated through model systems. Model system experiments have shown that while the sodium in CMC was insoluble in organic solvents and electrolyte, sodium can be extracted by contact between salt-containing electrolytes and CMC-containing anodes. The amount of sodium recovered in the model system closely corresponds with the amount that was recovered from cells after electrochemical operation. Other anode and cell components were also analyzed as potential sources of sodium, and the prospect of each of these as a source of sodium was explored. Finally, the effect of different levels of sodium content on cell performance was rigorously tested by doping lithium-ion electrolytes with NaPF6 and testing these electrolytes in pouch cells. Overall, we show that sodium can be a major contaminant extracted into the electrolyte during cycling in pouch cells, and investigate the impact of sodium content on critical performance metrics.

1 Ochida, M.; Domi, Y.; Doi, T.; Tsubouchi, S.; Nakagawa, H.; Yamanaka, T.; Abe, T.; Ogumi, Z. Influence of Manganese Dissolution on the Degradation of Surface Films on Edge Plane Graphite Negative-Electrodes in Lithium-Ion Batteries. Journal of the Electrochemical Society 2012, 159(7), A961-A966.
(Invited) Understanding Alkaline Metals As Anodes for Advanced Batteries
Authors: Meng Shirley
Published: December 2024

Successful integration of metallic lithium and sodium anodes into secondary batteries could enhance energy density and enable new forms of electrified transportation. However, the outlook for widespread adoption of alkaline metals as anodes in battery devices remains mixed. This comes in part from existing gaps in our understanding of the relationships connecting the initial state of reactive metals like lithium and sodium, their evolution with cycling, and end-of-life state. It remains important to develop novel tools and methods for material and cell characterization, cycling performance, safety, and recycling procedures for the metal-based batteries. In this talk, I will talk about the efforts currently ongoing to address these challenges and opportunities.
Metal–Organic Framework Monoliths for Lithium Metal Batteries with Long Cycle Lifetimes
Authors: Kim Chaejeong , Jeong Wooyoung , Shin Hong Rim , Jung Kyu-Nam , Lee Jong-Won
Published: December 2024

Lithium metal with low electrochemical potential and high theoretical capacity has attracted significant attention as an anode material for high-energy-density batteries. However, the practical application of Li metal anodes has been inhibited by the growth of Li dendrites during charge–discharge cycling. Nano- or micro-porous layers have been introduced at the Li/electrolyte interface to regulate the Li+ flux and stabilize the Li metal anode. However, such interlayers fabricated via slurry-casting have non-uniform porous structures containing interparticle voids due to the binders and solvents, which reduces the efficacy of the interlayer in suppressing dendritic Li growth. Herein, we report mechanically robust void-free metal–organic framework (MOF) monoliths that can effectively homogenize the Li+ flux and suppress dendritic growth. MOF monoliths (500 nm-thick) are directly grown on a polypropylene separator without binders via a simple chemical route with a void-free structure and mechanical robustness (Young’s modulus of ~7.8 GPa). The monolithic MOF film facilitates the filtration of large anions through the nanopores, resulting in an increased Li+ transference number. Furthermore, electrochemical simulations and experiments confirm that MOF monoliths with well-ordered nanopores but without interparticle voids effectively redistribute the locally concentrated Li+ flux over the Li anode, leading to reversible Li plating and stripping. A Li metal battery (full cell) with MOF monoliths operates stably over 300 cycles with a capacity retention of 96.6%. The interlayer design proposed in this study offers the possibility of commercializing high-energy-density Li metal batteries with long cycle lifetimes.