bluuebunny/crossref_metadata_2025 huggingface dataset:
Dualbeam Platform Applications in Lithium Battery Research
Authors: Liu Zhao , Zhang Minghao , Randolph Steven J , Winiarski Bartlomiej , Shojaee S. Ali , Pelapur Rengarajan , Wu Devin , Lemmens Herman , Meng Shirley
Published: July 2021

Lithium batteries are energy storage systems with highly complex microstructures. To understand the performance of the battery it is essential to accurately characterize the battery microstructure at multiple length scales. However, there are multiple challenges in battery characterization such as beam damage, imaging liquid phases and getting to representative volumes.

The DualBeam, also known as focused ion beam–scanning electron microscope (FIB-SEM) technique is an analytical method combining an ion beam for materials processing and an electron column for imaging to enable 2D and 3D characterization at the nanometer scale. In this presentation the application of three different DualBeam techniques for battery characterization and how to handle the imaging challenges are discussed for different sample types.

A battery separator is a beam sensitive sample and imaging conditions need to be optimized to avoid damaging the separator morphology. By using cryo techniques in a Ga-based FIBSEM, the cross-section and 3D structure of a separator sample is analyzed. The second example deals with a thick NMC electrode sample. Considering the thickness of the cathode (>70 µm) and the active particle size (~10 µm) particle size, a field of view >100 um is needed to get to a representative volume. The combination of Xe-plasma FIB (PFIB) with Avizo software is used to study the electrode microstructure evolution during cycling to better understand the degradation mechanism. The final example is about accessing the liquid-solid interphase inside of the electron microscope. By using a laser PFIB under cryogenic condition, the interphase of the liquid-solid in a Li-metal battery is explored, which is critical to decipher the root cause for cycling inefficiency.

DualBeam technology enables new analytical capabilities for materials research while opening up exciting opportunities for advancing battery development. It is expected to remain an indispensable technique for supporting battery innovation in both academic and industrial environments.
Development of Charge Transport Model to Study the Diffusion-Controlled Dissolution and Multi-Pit Interaction in Pitting Corrosion
Authors: Nguyen Van Anh , Newman Roger
Published: July 2021

Recently, we developed a reaction-transport model that incorporates diffusion, migration, and complexation to examine the charge transport inside a one-dimensional corrosion pit [1]. In this presentation, we will demonstrate the application of this model to study the “diffusion-controlled” dissolution of a metal in a pit from a more advanced point of view, such that the limiting anodic current density varies with the bulk NaCl concentration. An analytical result on anodic limiting current density as functions of pit depth, diffusivity, and chloride concentration was derived explicitly and coupled with artificial pit experiments. In a dilute chloride solution with low conductivity, the limiting current density is increased due to the increase of the migration flux near the pit mouth. On the other hand, the presence of Na+ at the bottom of the pit is significant for moderate to high bulk NaCl concentrations, which increases the limiting current density to some degree. The proposed full mass transport model can be used to predict limiting current densities at different ranges of bulk NaCl solutions. At above 2.5 M NaCl, the conventional diffusion-only model can give reasonably accurate results, but the effect of Na+ at the bottom of the pit on the solubility of metal ions and the limiting current density should be considered.

Finally, we will discuss the extension of the current work to the two-dimensional pit model to investigate the propagation and the interaction mechanism of multiple pits. The 2D multi-pit simulation under galvanostatic conditions shows the interaction between pits of different sizes. Due to the increase of the local chemistry inside the larger pit, the dissolution rate at the surface is faster and suppresses the growth of the neighboring pits.

Reference:

V. A. Nguyen, A. G. Carcea, M. Ghaznavi and R. C. Newman, The Effect of Cation Complexation on the Predicted “B” Value in Galvele’s Pit Model, J. Electrochem. Soc., 166, C3297 (2019).
Investigation of 2-Way Injection Method on Cu CMP Process
Authors: Kim Juhwan , Bae Chulwoo , Kwak Donggeon , Oh Seungjujn , Kim Taesung
Published: July 2021

Chemical mechanical polishing (CMP) is one of the process for planarization in semiconductor manufacturing. With the decrease of device size, copper (Cu) has been accepted as the material of interconnect for good performance. After electroplating process of Cu, overburden Cu surface is polished for planarization using CMP process. Generally, oxidants, dispersants, abrasive particles, chelating agents, and corrosion inhibitors are used in the Cu CMP slurry, and planarization of Cu is achieved by reaction of slurry components. Hydrogen peroxide is one of the oxidants which is widely used in Cu CMP slurry and react with Cu surface to form a passivation layer. In general, it is known that hydrogen peroxide is easily decomposed in the alkaline state. Therefore, in the alkaline slurry, decomposition of hydrogen peroxide can occur, which leads to deterioration of CMP performance.

In this study, a new slurry injection method is proposed as an alternative to prevent the decomposition of hydrogen peroxide that may occur when hydrogen peroxide and slurry are mixed. The concentration of hydrogen peroxide decreased when hydrogen peroxide and slurry are mixed, and accordingly, the removal rate decreased (Fig. 1(a)). It indicates that hydrogen peroxide is decomposed in alkaline state, and this affects the CMP performance. In order to prevent the decomposition of hydrogen peroxide, hydrogen peroxide and slurry were separately injected (2-way injection) during the CMP process. Fig. 1(b) shows the comparison of the removal rate between the general method and the 2-way injection method in the slurry supply system. As shown in the graph, when using the 2-way injection method, the removal rate is almost similar to that of the general injection method. Therefore, the 2-way injection method can replace the general injection method.

Figure 1. (a) the removal rate and concentration of hydrogen peroxide with slurry aging time, (b) the removal rate of general and 2-way injection method

Figure 1
Post Chemical Mechanical Planarization (CMP) Cleaning Using Hydrogen Dissolved Water
Authors: Park Kihong , Park Sang-hyeon , Hong Seokjun , Han Jongsoo , Jeon Sanghcuk , Kim Chang min , Kim Taesung
Published: July 2021

In current semiconductor manufacturing process, especially chemical mechanical manufacturing (CMP) process, ceria nanoparticle dispersed slurry is well known consumable for various CMP processes such as shallow trench isolation (STI), inter layer dielectric (ILD) CMP process, and etc. After CMP process, the ceria nanoparticles which are the sources of defects must be removed surely before performing the other processes. Typically, Standard clean solutions such as SC-1, SC-2, and etc. are applied to the post CMP cleaning process. These cleaning solutions are still effective to remove the residual ceria particles but there are several disadvantages such as quite harmful for health and need of additional treatments for wastewater. In this study, cleaning efficiency of the H2 gas dissolved water was evaluated comparing with DIW and other standard cleaning solutions. 4x4 cm2 of silicon dioxide film wafers were polished supplying ceria slurry and then immersed into the cleaning solutions such as DIW, standard clean solutions, and H2 dissolved water, respectively. Finally, we quantitively analyzed the residual cerium dioxide on the cleaned wafer surface by using inductively coupled plasma mass spectrometer (ICP-MS). H2 dissolved water removed residual ceria nano particles from the silicon dioxide film considerably comparing to DIW. Figure 1. show residual ceria ion concentration after cleaning process and cleaning efficiency calculated.

Figure 1
Direct Observation of Adsorption of Ceria Particles on the Silicon Dioxide Surfaces and Their Removal
Authors: Seo JIhoon , Ranaweera Charith , Gowda Akshay , Babu S.V.
Published: July 2021

We demonstrated that the movement of the single ceria particles located at the glass interface could be imaged in situ using evanescent wave (EW) microscopy. (1,2) Here, the flat glass surface of the lens became our model for the SiO2 film surface of interest. 3D trajectories, diffusion coefficients, and interactions of ceria particles with a glass surface at pH 3, 5, and 7 were investigated using EW microscopy. We also defined the types and characteristics of particle motions by analyzing the mean-square displacement (MSD) versus time curves. (1)

The removal of single ceria particles from the glass films in the cleaning solution was monitored in situ using EW microscopy coupled with a brush set-up. In situ measurement data collected during cleaning are likely to provide more important insights into the underlying mechanisms of various complex reactions that occur at the particles/brush–wafer interface. (3)

This talk will also introduce lateral force microscopy (LFM) mode in the atomic force microscopy (AFM) to obtain the removal force of single ceria particles from the SiO2 film. LFM is a powerful tool to monitor the torsion bending (or twisting) of the cantilever with contact mode, which is corresponding to the removal force. Types of particle removal mechanism depending on the characterization of single particles (size, shape, and surface) will be discussed. Our results will provide a better understanding of how the abrasive particles, the additives, and the film surfaces interact together during cleaning.

(1) Seo, J., Gowda, A., Khajornrungruang, P., Hamada, S., Song, T., & Babu, S. (2020). Trajectories, diffusion, and interactions of single ceria particles on a glass surface observed by evanescent wave microscopy. Journal of Materials Research, 35(3), 321-331.

(2) Seo, J., Gowda, A., Khajornrungruang, P., Hamada, S., & Babu, S. (2020). 3D trajectories and diffusion of single ceria particles near a glass surface and their removal. Journal of Materials Research, 1-10.

(3) Seo, J. (2020). A review on chemical and mechanical phenomena at the wafer interface during chemical mechanical planarization. Journal of Materials Research, 1-23.
Stability Enhancement of Pbo-Based Anodes through Facile Encapsulation in Carbon Nanofibers for Li-Ion Batteries
Authors: Pham Hiep , Park Jonghyun
Published: July 2021

Lead (II) Oxide (PbO)-embedded Carbon Nanofiber (CNF) anodes for lithium-ion batteries were prepared via the electrospinning method. While lead-based materials have several advantages over conventional graphite, including higher theoretical capacity and low cost, deleterious performance loss due to degradation caused by volume expansion remains as its main limitation. The use of carbon as an additive has been shown to stabilize the cycling performance and utilizing carbon nanostructures, namely nanofibers, can further substantially improve performance by accommodating volume change during lithiation/de-lithiation upon cycling as well as of batteries through capacity retention over several cycles. In this report, significant enhancement of battery performance in terms of specific capacity and cyclability is made using the prepared PbO/CNF anodes. The PbO particles were effectively embedded into the CNF, which significantly suppressed mechanical degradation of the electrode due to volume expansion and retained the PbO particles over numerous cycles and at high current. The PbO/CNF anode exhibits a high specific capacity of 375 mAh g-1 at a current of 200 mA g-1 (corresponding to ~1.2C) over 250 cycles compared 245 mAh g-1 for CNF, high current capability, and markedly improved stability, indicating its potential as an alternative to conventional graphite anodes.
(Invited) Disordered Rock-Salt Li3+XV2O5: A High-Rate Anode for Lithium-Ion Batteries
Authors: Liu Haodong , Zhu Zhuoying , Lu Jun , Xin Huolin L , Ong Shyue Ping , Liu Ping
Published: July 2021

Rechargeable lithium-ion batteries with high energy density that can be safely charged and discharged at high rates are desirable for electrified transportation and other applications. However, the sub-optimal intercalation potentials of current anodes result in a trade-off between energy density, power and safety. Here we report that disordered rock salt Li3+x
V2O5 can be used as a fast-charging anode that can reversibly cycle two lithium ions at an average voltage of about 0.6 volts versus a Li/Li+ reference electrode. The increased potential compared to graphite reduces the likelihood of lithium metal plating if proper charging controls are used, alleviating a major safety concern (short-circuiting related to Li dendrite growth). In addition, a lithium-ion battery with a disordered rock salt Li3V2O5 anode yields a cell voltage much higher than does a battery using a commercial fast-charging lithium titanate anode or other intercalation anode candidates (Li3VO4 and LiV0.5Ti0.5S2). DFT calculations reveal that lithium is displaced from stable octahedral sites to less stable tetrahedral sites, resulting in a suppression of the voltage. The crystal structure is well maintained throughout the process with a maximum volume change of 5.9%. This gives rise to exceptional cycling stability, with negligible capacity decay after 6000 cycles. Further, the material is shown to have exceptional rate capabilities, delivering over 40 per cent of its capacity in 20 seconds. Theoretical calculations unveil unique lithium redistribution mechanisms that are responsible for the high rate capability. At the beginning of Li insertion into Li3V2O5, diffusion of Li takes place by a concerted t-o-t mechanism where tetrahedral Li pushes its neighboring octahedral Li to another tetrahedral sites. At the end of the insertion process, direct tetrahedron to tetrahedron (t-t) diffusion is preferred. Both of these mechanism feature low activation energy values which result in rapid lithium diffusion and exceptional rate capabilities. This low-potential, high-rate intercalation reaction can be used to identify other metal oxide anodes for fast-charging, long-life lithium-ion batteries.
Three-Dimensional Mapping of Cycling Changes in Silicon-Graphite Composite Anodes Via Scanning Probe Microscopy
Authors: Huey Zoey , Ha Yeyoung , Finegan Donal P. , Norman Andrew , Al-Jassim Mowafak , Jiang Chun-Sheng , Han Sang-Don , DeCaluwe Steven C.
Published: July 2021

Silicon (Si) anodes have the potential to greatly improve the energy density of lithium-ion batteries due to the greater specific capacity of Si relative to standard graphite (Gr) anodes (1). However, Si anode implementation is limited by issues such as volumetric expansion during cycling and an unstable solid-electrolyte interphase (SEI). Composite anodes with Si and Gr particles can increase capacity while mitigating Si anode degradation. However, these electrodes can be challenging to characterize (and therefore optimize) due to their multiple components, heterogeneous surfaces, and the complex processes occurring there. Scanning spreading resistance microscopy (SSRM) is a form of scanning probe microscopy that measures local resistivity in a sample. By removing material with the probe tip while measuring resistivity, three-dimensional resistivity maps can be determined (2). For Si-Gr composite anodes, the different resistivities of the electrode components (e.g., Si, Gr, carbon, and lithium polyacrylate binder) allows direct identification through SSRM. 3D nanoscale volumes can then be created for both the whole electrode and the individual components.

This presentation will demonstrate 3D SSRM mapping of pristine and cycled anodes with three compositions – Si, Gr, and Si-Gr. By comparing changes in the morphology, thickness, and resistivity in the active material and SEI in each single-component electrode, the component distribution and evolution of the Si-Gr composite anode is better understood. SSRM results will be compared to chemical analysis techniques such as scanning transmission electron microscopy, energy dispersive x-ray spectroscopy, and electron energy loss spectroscopy to verify the component identification and to correlate chemical composition to resistivity. These data will then be correlated to electrochemical performance and used to further the development of Si-Gr electrodes with enhanced performance.

W.-J. Zhang, Journal of Power Sources, 196, 13 (2011).

C. Stetson, Z. Huey, A. Downard, Z. Li, B. To, A. Zakutayev, C. S. Jiang, M. M. Al-Jassim, D. P. Finegan, S. D. Han and S. C. DeCaluwe, Nano Lett (2020).

Figure 1
Influence of the Carbon Coating on the Electrochemical Performances of Si/C Composites for Lithium Ion Batteries
Authors: Gutierrez Mariana , Janot Raphael , Oudart Yohan , Guicheteau Rudy , Monconduit Laure , Louvain Nicolas , Morcrette Mathieu
Published: July 2021

Silicon, with a theoretical capacity of 3579 mAh/g, is one of the most promising anode materials as a substitute to graphite for Li-ion batteries. However, the lithiation process involves a volume expansion of 270% causing electrode fracture and the creation of an unstable SEI and fast capacity fading. Si/C composites made using petroleum pitch as carbon precursor are a good alternative to minimize these problems. An original way of synthesis has been developed by dispersing Si nanoparticles (40 nm in diameter, prepared by laser pyrolysis) in a pitch (either molten, or dissolved in a solvent) in order to obtain Si/C composites after thermal treatment. Even though pitch is a disordered carbon, after pyrolysis at 900°C, it exhibits a reasonable electronic conduction, has a reversible capacity of 280 mAh/g and acts as a buffer for the Si volume expansion. Si/C composites prepared using this method with 12 wt.% of Si present a reversible capacity of 600 mAh/g at the rate of C/5 and a coulombic efficiency at the first cycle up to 85%. We will discuss about the influence of the synthesis conditions on the texture of the composites and the resulting electrochemical performances. In order to study deeper the capacity retention, the Si/C composites were tested in full cells using NMC as the cathode. We will show that the control of the Si/C interface allows to obtain composites materials with high energy density up to 290 Wh/kg with a nice capacity retention.
Failure Mechanism for Silicon-NMC Batteries
Authors: Zhang Wei , Ban Chunmei
Published: July 2021

The ongoing development of renewable energy storage requires commercial lithium ion batteries with high energy density. Compared to the all-graphite (Gr) electrodes used in conventional lithium-ion batteries, silicon-based electrode is considered as an attractive alternative due to the high capacity-storage of silicon (Si). But the quick degradation of Si upon lithiation/delithiation is a critical problem that prevents its application. This presentation will investigate the failure mechanism of the full cell with a blended Si-Gr composite anode using multiple approaches. And a key finding is that the utilization of graphite plays an important role to maintain the reversible capacity in full cell, the increased voltage slippage will cause the reduced utilization of Gr. Based on these finding, we demonstrate that surface modification together with voltage controlled prelithiation facilitate the long-term cycling of Si-based anode in full cell. This enables a highly reversible Si-Gr anodes (mass loading, 2.5 mAh/cm2) in full cell demonstration with a specific capacity of 165 mAh/gNMC, and energy density of 450 Wh/kg, a cycling CE of 99.9% over 200 cycles, which shows great potential for commercial battery application.
(Invited) Rational Design of Localized High Concentration Electrolytes to Enable Long-Term Cycling of Si Anodes
Authors: Chae Sujong , Kwak Won-Jin , Han Kee Sung , Li Shuang , Engelhard Mark H. , Hu Jiangtao , Wang Chongmin , Li Xiaolin , Zhang Ji-Guang
Published: July 2021

To improve the energy density of conventional lithium ion batteries (LIBs), Si anode has been extensively investigated as a high-capacity alternative for carbonaceous anodes. However, large (~300%) volume change of Si anode during cycling and its continuous side reactions with electrolyte significantly limit the application of Si anodes. Herein, we have designed a localized high concentration electrolyte (LHCE) using a novel diluent with desired molecule structure. This electrolyte exhibits an optimized ion solvation structure and enabled largely improved cycling stability of Si anodes at both room and elevated temperatures. The full cells with Si/graphite composite anodes and LiNi0.5Mn0.3Co0.2O2 cathode have demonstrated 80% of capacity retention after 500 cycles in 1.74M LiFSI in DMC with 1H,1H,5H-Octafluoropentyl 1,1,2,2-tetrafluoroethyl ether (OTE) (0.51:0.84:0.84) at room temperature. The similar cells can also retain 76.5% of capacity in 300 cycles at 45 oC, which is 26% higher than that obtained in the baseline electrolyte. The Si/graphite anode cycled in the new electrolyte exhibits considerably suppressed SEI growth and well preserved dense structure. The design principle for LHCE developed in this work provides an important guideline for future design of practical electrolyte to realize long cycle life of Si anode and other high-capacity alloy materials with large volume changes.
Carbon Coating on Silicon for High-Performance Anode in Lithium-Ion Batteries
Authors: Zhou Shuo , Fang Shan , Fang Chen , Liu Gao
Published: July 2021

Silicon has attracted tremendous research interest as the next-generation anode material for lithium-ion batteries (LIBs) due to its approximately 10-fold higher capacity comparing to the graphite anode that is currently dominating the LIB market. Nevertheless, a critical drawback of silicon material is the dramatic volume change (>300%) during the lithiation and delithiation processes, which is a devastating destabilization factor for the silicon anode in battery cycling. Carbon coatings can serve as rigid framework to accommodate the volume change of silicon, to increase the conductivity of the silicon materials, and to protect the silicon surface from undesired side reactions. Here, we report two types of conductive carbon coatings on silicon materials through i) graphitization of a π-π stacking precursor poly(1-pyrenemethylmethacrylate) on SiO surface to encapsulate the SiO at a mild temperature, and ii) pyrolysis of polyvinylidene chloride precursor on silicon nanoparticle surface with stoichiometric ratio of sacrificial H and Cl elements that facilitate complete carbonization of the precursor. In addition, extended two‐phase transformation of carbon‐coated Si nanoparticles during electrochemical processes is examined.
A Simplified Model to Track Si Degradation in Various Systems
Authors: Ou Wenhan , Ban Chunmei
Published: July 2021

Silicon (Si) is considered one of the most promising anode materials for next generation lithium-ion batteries (LIBs), due to the extremely high specific capacity (3580mAh/g). However, it is challenging to use Si anodes for LIBs, because of the large volumetric changes and phase evaluation associated with lithiation/delithiation of Si. These intrinsic issues of Si lead to the rapid degradation in capacity during cycling, especially in full cells assembled with commercial lithium-ion battery cathodes. Efforts have been made in order to stabilize the Si anodes including developing new electrolytes to increase the surface stability, inventing new binders to enhance the mechanical integrity, and using nanoarchitecture to reduce mechanical failures. Leveraging the previous research, this work introduces a simple and effective method to fast identify the failure mechanism for Si anodes and decouple the impacts of surface instability and lithium trapping on the electrochemical behavior. Here, we will apply our model for various systems of Si half cells to discuss the effectiveness of adding the fluorinated electrolyte additive and the use of nanoparticles. Moreover, we will study the effects of surface modification via atomic/molecular layer deposition on the electrochemistry of Si anodes by using our developed method and provide the insights in designing the highly reversible Si anodes. In this study, we will investigate how these aforementioned factors may affect the stability of Si particles as well as the cycle performances. Assisted with electrochemical impedance spectroscopy (EIS), we will keep track with the SEI evolution on Si anode and connect with the capacity degradation in order to explain the importance of interface stability.
Safety Enhanced Quasi-Solid-State Electrolyte Based on Thiol-Ene Click Chemistry for Rechargeable Lithium Ion Batteries
Authors: Lim Da-ae , Jeong Bora , Kim Hye-Min , Kim Jeong-Yun , Kim Dong-Won , Lee ChulHaeng , Ahn Kyoung Ho , Lee Wontae
Published: July 2021

Lithium-ion batteries(LIBs) are considered the most effective power source for various applications such as mobile electronics, electric vehicles and energy storage systems due to their favorable energy density and long cycle life. However, liquid electrolyte currently used in LIBs has critical drawbacks such as flammability and leakage problem. To make a breakthrough of these problems, intensive efforts have been devoted to replace liquid electrolyte to safer electrolytes. Among various electrolyte systems, the chemically cross-linked gel polymer electrolytes can enhance the thermal safety of LIBs by encapsulating organic solvent in the polymer matrix. However, they usually contain a large amount of organic solvents to achieve high ionic conductivity, and side reactions may occur during the cross-linking reaction. However, they usually contain a large amount of organic solvents to achieve high ionic conductivity, and side reactions may occur during the cross-linking reaction, causing cell degradation due to impurities affecting electrochemical performance. In this work, we report the synthesis and electrochemical characteristics of quasi-solid-state electrolytes using thiol-ene click chemistry. During cell assembly, the cathode was coated with electrolyte precursor and thermally cured using thiol-ene click chemistry, since the click reaction can avoid side reactions and drive fast cross-linking under mild reaction conditions. The obtained cathode with quasi-solid-state electrolyte was applied to the lithium-ion cell composed of graphite anode and LiNi0.6Co0.2Mn0.2O2 cathode, and their electrochemical performance was investigated. Our result demonstrates that the quasi-solid-state polymer electrolyte can be a promising electrolyte for achieving high performance and enhancing battery safety.
Chemically Cross-Linked Gel Polymer Electrolytes for Highly Safe Lithium-Ion Batteries with Good Cycling Stability
Authors: Kim Jeong-Yun , Lim Da-ae , Jeong Bora , Kim Hye-Min , Kim Dong-Won
Published: July 2021

Liquid electrolytes used in lithium-ion batteries have many drawbacks such as high flammability, high reactivity toward electrode materials and solvent leakage. To overcome these problems, most recent research has focused on synthesis and characterization of highly conductive gel polymer electrolytes containing large number of organic solvents in the polymer matrix. However, there are still many hurdles to overcome before they can be applied to lithium-ion batteries. Since a large amount of organic solvent is required to achieve high ionic conductivity, battery safety is not significantly enhanced. In this study, we synthesized chemically cross-linked gel polymer electrolyte containing small amounts of organic solvents. The chemically cross-linked gel polymer electrolyte enhanced thermal safety of battery due to the effective trapping ability of organic solvents in the polymer matrix. The resulting gel polymer electrolyte was applied to lithium-ion cells composed of graphite anode and LiNi0.6Co0.2Mn0.2O2 cathode. We investigated their electrochemical performance, thermal stability, and solvent leakage behavior.
(Invited) Quantifying Capacity Losses Due to Solid-Electrolyte Interface Formation
Authors: Toney Michael F
Published: July 2021

Understanding the origins of failure and limited cycle life in lithium-ion batteries (LIBs) requires quantitative linking capacity-fading mechanisms to electrochemical and chemical processes. This is challenging in real systems where capacity is lost during each cycle to both active material loss and solid electrolyte interphase (SEI) evolution. In this talk, I will describe the model system-based approach that we have adopted that combines precision electrochemical measurements of the Coulombic efficiency (CE) and x-ray measurements of the SEI layer and active materials loss. By contrasting these independent quantities, we obtain insight into the SEI growth and evolution. I will discuss how we have used X-ray reflectivity (XRR) to obtain nanoscale insight into solid electrolyte interfaces (SEI) on model anode surfaces that implicate electrochemically formed LiF as playing a major functional role in the SEI. I will also describe how XRR tracks the thickness of a-Si thin films and when this is compared to the CE, we can quantify SEI growth over several cycles. The methodology we are adopting allows to quantitatively track the desirable and undesirable electrochemical processes.
In Situ Investigations on LiNiO2 during Post-Synthesis Heating in Air
Authors: Li Hang , Hua Weibo , Indris Sylvio
Published: July 2021

Enhancing cathode materials with high energy density and low cost has become the main direction of development in battery industry [1]. In order to achieve this goal, LiNi
x
Co
y
Mn1-x-y
O2 (NCM) and LiNi
x
Co
y
Al1-x-y
O2 (NCA) cathode materials with increased Ni contents (0.6 ≤ x ≤ 1) have been gradually put into mass production and applied in electric vehicles [2]. If the Ni content is being increased continuously, finally we will probably go back to LiNiO2, a well-known yet traditional material. Numerous efforts have been made to improve its stability and usability up to now [3, 4]. Nevertheless, an easy and effective method is still waiting to be discovered. For this purpose, we study the structural changes of LiNiO2 during the heat treatment process in air using nuclear magnetic resonance, synchrotron radiation diffraction and absorption spectroscopy. Various reactions such as oxygen loss, lithium transport and phase transitions take place in different temperature regions. During the thermal treatment, a thin layer is formed in-situ on the surface of LiNiO2 as a consequence of oxygen loss. The thickness of this layer could be precisely adjusted through changing the heating temperature. A thicker layer has positive effects on protection of LiNiO2 but it blocks the migration of Li ions, resulting in larger over-potential and lower capacities. After heating to 400 °C an excellent stability has been observed with 93% capacity retention after 180 cycles. In summary, the properties of LiNiO2 could be adjusted through a post-synthesis treatment without additional chemicals. This method could also be applied to a larger class of NCM or NCA materials as a new modification strategy.

References:

[1] Li, Wangda, Evan M. Erickson, and Arumugam Manthiram. "High-nickel layered oxide cathodes for lithium-based automotive batteries." Nature Energy (2020): 1-9.

[2] Bianchini, Matteo, et al. "There and back again—the journey of LiNiO2 as a cathode active material." Angewandte Chemie International Edition 58.31 (2019): 10434-10458.

[3] Li, Hongyang, et al. "An unavoidable challenge for Ni-rich positive electrode materials for lithium-ion batteries." Chemistry of Materials 31.18 (2019): 7574-7583.

[4] Jung, Sung Hoo, et al. "Ni‐Rich Layered Cathode Materials with Electrochemo‐Mechanically Compliant Microstructures for All‐Solid‐State Li Batteries." Advanced Energy Materials 10.6 (2020): 1903360.
(Invited) Cation Transport across Interfaces in Solid-State Li Batteries
Authors: Rettenwander Daniel
Published: July 2021

Despite all the progress made in the development of solid-state Li batteries (SSLB), interfaces arise as the main bottleneck impeding their practical realization. In particular, the interfacial regions between the individual components of a cell comprising those formed between ceramic electrolytes and Li metal and ceramic high-voltage cathodes as well as interfaces between ceramic particles and the polymeric matrix in composite electrolytes are identified to be challenging.1 For example, current constriction that arise from inhomogeneous electrical field distributions at the Li metal | solid-electrolyte interface leads to the formation of dendritic structures at high current rates.2 Forming a good interface between the solid electrolyte and cathode material requires high temperature treatments that leads to the formation of an interphase layer that impedes the ion transport across the interface.3 To unroll the beneficial properties of a composite membrane both components, ceramic particles and polymer matrix, must contribute to the long-range ion transport. Due to the high interface resistance between the components, ionic transport does not take place in ceramic particles; hence, the ceramic has only the role of a passive filler rather than improving the membrane properties.4

Inspired by these challenges, mitigation strategies to overcome these bottlenecks will be presented. For example, strategies that (i) enable cycling at very high rates up to 6 mA cm-2 using different surface treatments and current waveforms, (ii) change the mechanical properties at the interface to potentially avoid crack formation that ultimately leads to short circuits, and (iii) lower the interfacial resistance between ceramics and polymers by orders of magnitude.5 Moreover, we show that Co interdiffusion not only lead to the formation of resistive interphases, but is also detrimental for the electrical transport properties and electrochemical stability of solid electrolytes.

References

(1) A. Banerjee, et al. Chem. Rev.
2020, 120, 6878–6933.

(2) J. Kasemchainan, et al. Nat. Mater.
2019, 18, 1105-1111.

(3) K. Park, et al. Chem. Mater.
2016, 28, 8051–8059.

(4) J. Zheng, et al. Angew. Chemie Int. Ed.
2016, 55, 12538–12542.

(5) E. Kuhnert, et al. Cell Reports Phys. Sci.
2020, 1, 100214.

Acknowledgement

Financial support by the Austrian Federal Ministry for Digital and Economic Affairs, the National Foundation for Research, Technology and Development and the Christian Doppler Research Association (Christian Doppler Laboratory for Solid-State Batteries) and the Austrian Science Fund (FWF) (project no. P25702) is gratefully acknowledged.
Determination of Lithium Diffusion Coefficient in FeS2 through Improved Galvanostatic Intermittent Titration Technique (GITT) Modeling
Authors: Horner Jeffrey Scott , Whang Grace , Ashby David , Dunn Bruce S. , Talin Alec Alec , Roberts Scott A.
Published: July 2021

Significant, recent efforts have been directed towards modeling lithium-ion batteries to optimize their performance and design. These models depend highly on physical parameters that must be evaluated experimentally for the system of interest. One of the most critical of these parameters is the chemical diffusion coefficient for lithium inside the active cathode material. Galvanostatic Intermittent Titration Technique (GITT) is a commonly used technique that can evaluate the diffusion coefficient, as well as other important information about the cell such as the reaction rate constant and open circuit potential. Despite its popularity, there remain several issues with the existing method of analyzing GITT data. Notably, the conventional method for extracting diffusion coefficients from GITT data relies on numerous assumptions, applies only at short discharge times, and lacks evidence validating the obtained coefficients.

In this work, we describe a new method of extracting diffusion coefficients from GITT data. This method involves directly fitting a GITT pulse to a one-dimensional, single particle electrochemical model and can be applied for both ideal and non-ideal solution theory. We apply this approach to experimental measurements at two temperatures for the intercalation regime of FeS2, a conversion cathode material. Results are compared to the conventional method of evaluating diffusion coefficients from GITT data as well as diffusion coefficients obtained from electrochemical impedance spectroscopy. Diffusion coefficients are found to be higher for direct fitting, and more than an order of magnitude difference is observed between ideal and non-ideal diffusion coefficients. The modeling is also extended to a distribution of particles, and we show that the distribution behaves as a single particle with an effective particle radius proportional to the total volume to surface area ratio. Finally, the new diffusion coefficients are validated against discharge data for the cell, and it is shown that a reasonable prediction to the experimental data can be achieved using a single particle model. However, this is only possible with a non-ideal diffusion model, and high variation is observed across predictions obtained using other diffusion coefficient evaluation methods. This work demonstrates the susceptibility of electrochemical modeling to transport parameters and offers a simple, yet improved, method for evaluating diffusion coefficients from experimental GITT measurements.

Supported by the Laboratory Directed Research and Development program at Sandia National Laboratories, a multimission laboratory managed and operated by National Technology and Engineering Solutions of Sandia, LLC., a wholly owned subsidiary of Honeywell International, Inc., for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-NA-0003525.
Electrochemical Healing of Dendrites in Garnet-Based Solid Electrolytes
Authors: Parejiya Anand , Essehli Rachid , Amin Ruhul , Wood David L. , Belharouak Ilias
Published: July 2021

Garnet oxides are a promising material family for solid-state batteries (SSBs). Dendrite formation in solid electrolytes critically limits the applicability of SSBs because of limiting coulombic efficiency and power capability. Herein, the authors report in operando electrochemical healing of dendrites in a garnet-based solid electrolyte (SE). Dendrites are deliberately formed at high operational current density (2 mA cm−2) beyond the critical current density (0.55 mA cm−2) of the garnet SE. Electrochemical impedance spectroscopy and scanning electron microscopy were used to confirm dendrite growth in the SE. Dendrites were subsequently healed electrochemically via plating and stripping at 20 and 1 µA cm−2 current densities. Removal of dendrites was shown by an increase in bulk and interfacial resistance and a progressive increase in polarization during galvanostatic plating and stripping. High local current density at the dendrite tips was identified as the mechanism for preferentially removing dendrites electrochemically. Dendrite detection and healing methods discussed here are crucial for extending the life of SSBs.

Figure 1
(Invited) Can Fast Charging Rechargeable Lithium Batteries be a Reality?
Authors: Liaw Boryann (Bor Yann) , Zhang Yulun , Lin Yuxiao
Published: July 2021

Rechargeable Li batteries (RLB) hold the promise for truly high energy design for future electrification and energy storage applications. Besides constrained cycle life issues with RLB, whether RLB can sustain fast charging at a rate comparable with Li-ion batteries remains as a concern for practical applications. Here we intend to explore this possibility and understand the underlying issues with RLB under fast charging conditions. Experimental work, electrochemical characterization, data analytics and modeling will be used to understand those issues to clarify what underlying issues that need to be addressed.
Modeling First Stages of Solid-Electrolyte Interphase (SEI) in LiPF6/EC Electrolytes Using Molecular Dynamics Simulations
Authors: Alzate-Vargas Lorena , Allu Srikanth , Fattebert Jean-Luc
Published: July 2021

The performance of lithium-ion batteries(LiB) using organic electrolytes depends strongly in the formation of a stable solid electrolyte interphase (SEI) film. Elucidating the dynamic evolution and spatial composition of the SEI can be very useful to study the stability of the structures and could also optimize the formation cycles of LiB. We propose a classical molecular dynamics simulation protocol for predicting the first stages of the SEI using a reaction method involving the decomposition of EC and LiPF6 molecules in the electrolyte. We are able to accelerate, on the order of nanoseconds, the formation of SEI components near the anode surface, such as gases (C2H4), inorganic (Li2CO3, and LiF) and organic (LEDC). We expect to expand this protocol to explore different electrolyte compositions and additives and for further advances in Li-ion battery technology

This research is supported by the U.S. Department of Energy's Vehicle Technologies Office.
A Control-Oriented Single Particle Model with Electrolyte Dynamics and Stress-Diffusion Coupling
Authors: Riemann Brody James Corey , Li Jie , Zhu Yaqi , Landers Robert G. , Park Jonghyun
Published: July 2021

Full electrochemical models are well-established as the standards for accurately predicting battery behavior. These are especially useful for cell design since performance can be evaluated based on various model parameters. Conventional models can be coupled with additional physics such as diffusion-induced stress, crack propagation, and battery degradation mechanisms to test different physical phenomena. However, these models are too computationally intensive to implement in battery management systems (BMSs), which utilize control and estimation algorithms to monitor performance and ensure safety. Single particle models (SPMs), which are computationally efficient approximations of pseudo-two-dimensional (P2D) models, are often used instead. However, most SPMs are only valid for low C-rates. In this paper, a new ODE-based SPM is proposed that captures high C-rate effects by including electrolyte physics and stress-diffusion coupling. Models describing these physics are validated by comparing simulation results to the P2D model at several C-rates. A single lumped parameter is used to quantify the intensity of the stress-diffusion coupling in an electrode. Simulation results are presented to show how variation of this parameter affects charge-discharge cycle times at different C-rates. Next, the improved SPM is linearized and presented as both state space and transfer function models. The frequency responses of the linearized SPM and P2D model are compared with and without stress-diffusion coupling. Further, the effects of varying the stress-diffusion coupling intensity on the frequency response are discussed. The proposed linearized model is more computationally efficient than full electrochemical and P2D models, and includes key physics that are missing in most low-order battery models. As a result, the proposed model is well-suited for a wide variety of BMS applications and offers improvements at high C-rates that are necessary for fast charging applications.
Theoretical and Experimental Investigations of Fluoroethylene Carbonate Electrolyte for High Performance Ni-Rich 18650 Lithium-Ion Batteries
Authors: Duangdangchote Salatan , Sawangphruk Montree
Published: July 2021

Lithium-ion batteries have been used widely for portable electronic devices and electric vehicles (EVs). To date, the Ni-rich LiNi0.88Co0.09Al0.03O2 layered material is a promising cathode for next-generation and advance energy storage devices.(1) Unfortunately, the Ni-rich cathode suffers from capacity fading upon cycling and poor rate performance that limit its application. To overcome these concerns, the uses of Fluoroethylene Carbonate (FEC) can effectively improve the performance and safety of the cells. Herein, the effects of the FEC concentrations on the performance of Ni-rich NCA lithium-ion batteries were investigated. We performed the combination of theoretical molecular dynamic simulations (MD) along with experimental in 18650 scale to study the electrolyte transport properties, electrochemical performances, and large-scale battery safety. We hope that the fundamental understanding on the effect of FEC could be useful for further development of the future lithium-ion batteries.

REFERENCES

Li, Y.; Tan, C.; Wei, S.; Cui, L.; Fan, X.; Pan, Q.; Lai, F.; Zheng, F.; Wang, H.; Li, Q. Mater. Chem. A, 2020, 8, 21649-21660.
(Invited) Role of the Electrolyte on Li Cation Electrodeposition and Intercalation
Authors: Balbuena Perla B. , Perez Beltran Saul , Angarita Gomez Maria , Guo Ningxuan , Ospina-Acevedo Francisco A
Published: July 2021

Cation transport through the electrolyte to the anode is one most important steps to understand desolvation and diffusion through the electrolyte phase To help understanding this step, there is a sustained development of sophisticated in situ surface science and electrochemical techniques, and first-principles based computational methods. In this work, we analyze the structure and dynamics of state-of-the-art electrolytes particularly at interfaces of typical intercalation anodes. We use classical reactive molecular dynamics and ab initio molecular dynamics to characterize the interfacial systems, and constrained molecular dynamics to investigate the role of highly structured solvation structures on cation deposition and intercalation.
(Invited) Towards Deterministic 3D Li-Ion Electrode Architectures Via Electrodeposition of Molybdenum Oxide Onto CNT Foams
Authors: Augustyn Veronica , Kamboj Ishita , Spencer Michael , Bradford Philip , Hossain Md Milon , Mukherjee Partha P. , Kabra Venkatesh , Vishnugopi Bairav Sabarish
Published: July 2021

Three-dimensional (3D) deterministic design of electrodes could enable simultaneous high energy and power density for electrochemical energy storage devices. The goal of such electrode architectures is to provide adequate charge (electron and ion) transport pathways for high power while maintaining high active material loading (> 10 mg cm-2) for high areal and volumetric capacity. However, it remains a challenge to fabricate such electrodes with processes that are both scalable and reproducible. Towards this end, I will discuss how the fabrication of such an electrode is made possible by combining highly tunable, free-standing, and aligned CNT foams with aqueous electrodeposition of a model intercalation-type transition metal oxide, MoO3. Morphological characterization including X-ray micro computed tomography indicate that the obtained composite is highly homogenous. Electrodes with active mass loading up to 18 mg cm-2 can reach near-theoretical Li-ion intercalation capacities within 1.7 hours. The highest mass loading electrodes also led to areal and volumetric capacities of 4.5 mAh cm-2 and 290 mAh cm-3 with 55% capacity retention for charge/discharge times of 10 minutes. I will also describe the use of mesoscale modeling to understand and ultimately, predict the performance of this electrode architecture. Overall, our work demonstrates a scalable, deterministic 3D electrode design strategy using electrodeposition and free-standing, aligned CNT foams that lead to high areal and volumetric capacities and good rate performance due to well-distributed charge transport pathways.