bluuebunny/crossref_metadata_2025 huggingface dataset:
Anion Selection Criteria for Water-in-Salt Electrolytes
Authors: Reber David , Grissa Rabeb , Becker Maximilian , Kuehnel Ruben-Simon , Battaglia Corsin
Published: November 2022

Water-in-salt electrolytes have enabled the development of novel high-voltage aqueous lithium-ion batteries due to their wide electrochemical stability window. Here, we explore why analogous sodium electrolytes have struggled to reach the same level of electrochemical stability and compare solution structure and electrochemical stability for eleven sodium salts, selected among the major classes of salts proposed for highly concentrated electrolytes.[1-3] We relate the water environment established for each anion to its position in the Hofmeister series, finding a strong correlation between the chaotropicity of the anion and the resulting electrochemical stability of the electrolyte. We discuss the importance of the solid-electrolyte interphase for stable battery performance, how it relates to the choice of anion, and further show that the search for suitable sodium salts is complicated by the fact that higher salt concentrations are needed than for their lithium equivalents.[4] Reaching such a high concentration of 25 to 30 mol/kg with one or a combination of multiple sodium salts that have the desired properties remains a major challenge. We conclude that alternative approaches such as mixed water/organic solvent or dual-cation electrolytes should be pursued to enable the development of high-voltage aqueous sodium-ion batteries. We demonstrate the potential of the mixed-solvent approach by showing that the water solubility of NaTFSI can be increased from 8 to 30 mol/kg in the presence of ionic liquids. Such a ternary electrolyte, based on highly chaotropic anions, enables stable cycling of a 2 V-class sodium-ion battery based on the NaTi2(PO4)3/Na2Mn[Fe(CN)6] electrode couple for 300 cycles at 1C with a Coulombic efficiency of >99.5%.[5]

References:

[1] Kühnel, R.-S.; Reber, D.; Battaglia, C., A High-Voltage Aqueous Electrolyte for Sodium-Ion Batteries. ACS Energy Lett.
2017, 2, 2005-2006.

[2] Reber, D.; Kühnel, R.-S.; Battaglia, C., Suppressing Crystallization of Water-in-Salt Electrolytes by Asymmetric Anions Enables Low-Temperature Operation of High-Voltage Aqueous Batteries. ACS Materials Letters
2019, 1, 44-51.

[3] Reber, D.; Takenaka, N.; Kühnel, R.-S., Yamada, A.; Battaglia, C., Impact of Anion Asymmetry on Local Structure and Supercooling Behavior of Water-in-Salt Electrolytes. J. Phys. Chem. Lett.
2020, 11, 4720

[4] Reber, D.; Kühnel, R.-S.; Battaglia, C., Stability of aqueous electrolytes based on LiFSI and NaFSI. Electrochim. Acta
2019, 321, 134644

[5] Reber, D.; Grissa, R.; Becker, M.; Kühnel, R.-S.; Battaglia, C., Anion Selection Criteria for Water-in-Salt Electrolytes. Adv. Energy Mater.
2021, 11, 2002913
Effect of Calendering on Local Ionic and Electronic Transport of Porus Electrodes
Authors: Liu Baichuan , James Nicole , Wheeler Dean , Mazzeo Brian A.
Published: November 2022

The microstructure determines transport properties in lithium-ion battery electrodes. There is generally a tradeoff between electronic and ionic transport when adjusting the microstructure. One way of adjusting the microstructure is through calendering, where the electrode is compressed following drying. Understanding how calendering affects not only the average but also the local electronic and ionic transport provides additional insight when developing battery electrodes and engineering better batteries. If a correlation exists between the two properties, an optimal porosity that maximizes both ionic and electronic transport could be determined.

In order to better understand the influence of microstructure on these transport properties, we tested a series of commercial-grade electrodes including NMC cathodes, graphite anodes, and a graphite-silicon anode. The local electronic conductivity of the electrodes was found using a micro-flexible-surface probe previously developed by our research group [1]. Likewise, the local ionic conductivity was found using an aperture probe previously developed by our research group [2]. All electrodes were obtained from Argonne National Laboratory in calendered and un-calendered states.

Through testing various electrodes before and after calendering, we found that not every electrode experienced an increase in electronic conductivity after calendering, and that in general heterogeneity of the electronic conductivity decreased after calendering. The local ionic resistance, as indicated by MacMullin number, was found to increase after calendering, as expected. Figure 1 illustrates the local ionic and electronic transport results for one cathode. Ionic transport was found to be almost solely influenced by porosity. However, electronic transport was found to be influenced by a variety of factors including the nature, distribution, and connectivity of conductive materials.

[1] Vogel et al., J. Electrochem. Soc. 168, 100504 (2021).

[2] Liu et al., ECS Meeting Abstracts 2021, 444.

Figure 1
A Co-Axial Microtubular Flow Battery Cell with Ultra-High Volumetric Power Density
Authors: Liu Nian
Published: November 2022

Flow batteries are a promising energy storage solution. However, the footprint and capital cost need to be further reduced for flow batteries to be commercially viable. The flow cell, where electron exchange takes place, is a central component in flow batteries. Improving the volumetric power density of the flow cell (W/Lcell) can reduce the size and cost of flow batteries. While significant progress has been made on flow battery redox, electrode and membrane materials to improve energy density and durability, conventional flow batteries based on planar cell configuration exhibit a large cell size with multiple bulky accessories such as flow distributors, resulting in low volumetric power density. In this talk, I will introduce a new co-axial microtubular (CAMT) flow battery cell configuration that significantly improves volumetric power density by reducing the membrane-to-membrane distance by almost 100 times and eliminating completely the bulky flow distributors. Using zinc-iodide chemistry as a demonstration, our CAMT cell shows peak charge and discharge power densities of 1322 W/Lcell and 306.1 W/Lcell compared to average charge and discharge power densities of < 60 W/Lcell and 45 W/Lcell of conventional planar flow battery cells. The battery cycled for more than 220 hours, corresponding to > 2,500 cycles at off-peak conditions. Furthermore, the CAMT cell has been demonstrated to be compatible with zinc-bromide, quinone-bromide, and all-vanadium chemistries. The CAMT flow cell represents a device-level revolution to enhance the volumetric power of flow batteries and potentially reduce the size and cost of the cells and the entire flow battery.

Publication:

https://chemrxiv.org/engage/chemrxiv/article-details/62070e98bd05a04ae103fa7e

Figure 1
Engineering Micro-Structured Lithium-Ion Battery Electrodes for Enhanced Performance Using High-Throughput Ultrafast Laser Ablation
Authors: Tremolet de Villers Bertrand J. , Kern Dana , Dunlap Nathan A. , Usseglio-Viretta Francois L. E. , Weddle Peter J , Sunderlin Nathaniel , Major Joshua , Finegan Donal P.
Published: November 2022

As the demand for electric vehicles continues to grow, secondary batteries with larger storage capacities, faster charging times, and lower manufacturing costs are desired. Current U.S. Advanced Battery Consortium cell-level targets for low-cost and fast charge lithium-ion batteries (LiBs) for electric vehicles include energy densities of >275 Wh/kg, cost less than $100/Wh, and charge to more than 80% capacity within 15 minutes.1 One way to increase capacity is to increase the thicknesses of the electrodes so that there is more active lithium-ion storage material in the cell; however, increasing electrode thickness is usually limited to less than approximately 150 µm due to problems with through-plane Li-ion diffusion. Too-thick electrodes exhibit poor rate performance and with Li plating problems that accelerate cell degradation at charging rates > 1C. Recently, we have demonstrated that laser-ablated micro-structures, such as pores or channels, in thick battery electrodes improves the performance of LiBs.2 Using advanced predictive modelling, we have explored the limitations of planar electrodes for fast charge performance and the importance of microscale features for improving ion-transport.3,4 The cell’s energy density and capacity retention is significantly improved by engineering the appropriate micro-structure geometry. Here, we will present some of the technical challenges of accomplishing the ultrafast laser ablation and provide examples of advanced characterization of the patterned electrodes to understand their effects on electrode performance. We will also describe methods to scale-up the laser processing to enable high-throughput roll-to-roll fabrication of micro-structured thick battery electrodes which requires fast and accurate steering of the emitted laser light. Our results provide an overview for translating the technology from the lab scale to industry-relevant manufacturing.

References:

1. https://uscar.org/download/246/energy-storage-system-goals/12840/low-cost-fast-charge-ev-goals.pdf

2. N. Dunlap, D. B. Sulas-Kern, P. J. Weddle, F. Usseglio-Viretta, P. Walker, P.l Todd, D. Boone, A. M. Colclasure, K. Smith, B. J. Tremolet de Villers, and Donal P. Finegan, J. Power Sources, (2022)

3. F. L. E. Usseglio-Viretta, W. Mai, A. M. Colclasure, M. Doeff, E. Yi, and K. Smith, Electrochim. Acta, 342 136034 (2020).

4. W. Mai, F. L. E. Usseglio-Viretta, A. M. Colclasure, and K. Smith, Electrochim. Acta, 341 136013 (2020).
Chemometric and Machine Learning Analysis of Lithium Concentration and Solvation Behavior in Li-Ion Battery Electrolytes
Authors: Meyer Lydia , Kinder Collin , Porter Jason Morgan
Published: November 2022

The demand for batteries is rapidly growing across a range of technologies. The increasingly diverse use cases for batteries require various capabilities, particularly requirements for high energy densities, that are currently unmet by traditional Li-ion batteries. Electrolyte stability proves to be a bottleneck for battery advancement towards energy dense chemistries beyond Li-ion, including metal anodes. In situ spectroscopy tools, such as Fourier transform infrared (FTIR) spectroscopy, Raman spectroscopy, and X-ray spectroscopy, have provided insight into critical molecular-level interactions in batteries during cycling. These in situ tools have yielded continuous improvement of electrolyte properties. Spectroscopy datasets, however, contain many nuances that challenge meaningful human understanding. Artificial intelligence and chemometric tools can be coupled with in situ spectroscopy to find relevant interpretations of spectral datasets and elucidate complex molecular phenomena. In this research, an analysis was performed on FTIR spectroscopy data from an electrolyte composed of LiPF6 in ethylene carbonate (EC) and ethyl methyl carbonate (EMC) to discern solvation behavior using principal component analysis (PCA) and a convolutional neural network (CNN). PCA pinpointed exact band locations of solvation shifting behavior in the IR spectra and improved understanding of the relationship between lithium concentrations and peak changes. The CNN was trained with spectral datasets of electrolytes with known lithium concentrations and then could predict lithium concentrations from spectral datasets with extraordinarily high accuracy. Additionally, the CNN interpreted FTIR spectral datasets from a graphite half-cell with EC/EMC/LiPF6 electrolyte and accurately determined the lithium concentration in the bulk electrolyte. The CNN also observed lithium depletion events (up to 10% lithium depletion) in the graphite anode during fast-charging cycles of the galvanostatic intermittent titration technique. This research breaks new ground on using advanced computational tools for in situ spectroscopic analysis of battery electrolytes and demonstrates an improved understanding of complex molecular-level phenomena in electrolytes.
(Invited) Redox Flow Battery Research, Development, and Manufacturing
Authors: Wang Wei
Published: November 2022

Redox flow batteries are increasingly recognized as a promising candidate for large-scale grid energy storage due to their unique architecture that decouples the power and energy. This feature is desirable for long-duration energy storage since it enables the flow batteries to singularly increase the duration without the concomitant cost increase of the power component. This presentation will give an overview of the current research and development of the redox flow battery technologies, especially considering their manufacturing challenges from material synthesis, electrolyte formulation, cell components, and devices to the systems. Focuses will be given to developing organic redox-active molecules, new testing technics, testing protocols, and procedures. A data-driven flow battery research, development, and deployment platform, a digital twin flow battery, will also be discussed.
Thermogravimetric Analysis - Mass Spectrometry: A Simple Method for the Measurement of Small Molecules Adsorbed to the Surface of Electrodes
Authors: Evans Kieran
Published: November 2022

The presence of moisture on electrodes can have substantial effects on the overall performance of a lithium-ion battery. Several processes, including reactions with the conducting salt during operation can lead to this reduction in performance, as well as mechanical problems such as swelling.

Removing this moisture from electrodes is therefore an incredibly important aspect of the manufacturing process, as is having a method for the determination of moisture. Currently, Karl-Fisher methods are the most common techniques for the determination of water in electrode samples. However, there are several disadvantages to this method including the need to handle the sample before analysis, allowing for the introduction of more moisture into the sample.

Thermogravimetric analysis-mass spectrometry, on the other hand, allows for analysis of these samples without the need of extensive preparation or chemical reagents.

An arguably more important aspect of TG-MS is that mass spectrometers have the capability of measuring a wide range of ion fragments, allowing for a range of different species to be analyzed with no significant changes in experimental parameters. Furthermore, thermogravimetric analysis provides information regarding the temperature at which species adsorb and desorb from the surface of the electrode.

This work aims to describe the use of thermogravimetric analysis hyphenated to mass spectrometry (TG-MS) for the analysis of water and carbon dioxide on both anode and cathode samples, exemplifying the vastly different adsorption/desorption behaviour that these materials can demonstrate.
Measuring Lithium-Ion Transport Properties in Electrolytes Via in Situ Infrared Spectroscopy
Authors: Porter Jason Morgan , Skweres Sean , Meyer Lydia
Published: November 2022

Electrolyte transport capability is a critical measure of battery function for both current Li-ion technology and chemistries beyond Li-ion. Ion transport plays a vital role in fast-charging, lithium plating, and performance under extreme temperature and cycling conditions. Though traditional electrolytes have been widely studied, current experimental methods do not allow for simple measurements of transport properties, often requiring large electrolyte volumes, long experiment times, and a dilute assumption. In this research, we developed analytical models that accurately predict apparent diffusion coefficient and transference number from numerical models of electrolyte ion concentrations in a lithium symmetric cell. The first analytical model utilized one-dimensional diffusion to predict the transient response of lithium concentration in the bulk electrolyte to an applied current. The second analytical model predicted lithium-ion concentration decay in a Li/Li cell at the electrode surface following a brief current pulse. The analytical models were used to fit numerical finite difference simulations of Li/Li cell performance to predict transport properties. This result suggests that current pulse methods can be applied to experimentally ascertain electrolyte diffusion properties. A new diagnostic is under development for characterizing electrolyte transport properties, diffusion coefficient and transference number, using the current pulse method applied to an in situ symmetric Li/Li cell. This diagnostic utilizes Fourier transform infrared spectroscopy and attenuated total reflectance to measure transport properties with low volumes of electrolyte and short experiment times. This capability may enable simple and rapid measurement of transport properties for electrolyte candidate screening and enrich broader understanding of electrolyte transport.
(Digital Presentation) Effects of Sulfur Cathode Topography on Cycling of Practical Li–S Batteries
Authors: Shi Lili , Anderson Cassidy , Feng Shuo , Liu Jun , Xiao Jie , Lu Dongping
Published: November 2022

Lithium–sulfur (Li–S) batteries are one of the most promising next-generation energy storage technologies due to their high theoretical energy and low cost.[1-2] However, Li–S cells with practically high energy still suffer from a very limited cycle life with reasons which remain unclear.[3] Here, through cell study under practical conditions, we prove that an internal short circuit is a root cause of early cell failure and was ascribed to the crosstalk between the S cathode and Li anode. The cathode topography dictates S reactions through influencing the local resistance and electrolyte distribution, particularly under lean electrolyte conditions. The inhomogeneous reactions of S cathodes are easily mirrored by the Li anodes, resulting in exaggerated localized Li plating/stripping, Li filament formation and eventually cell internal short circuit. Manipulating cathode topography was proven effective to extend the cell cycle life under practical conditions. The findings of this work shed new light on the electrode design for extending cycle life of high-energy Li–S cells, which are also applicable for other rechargeable Li or metal batteries. Details of the progress will be discussed at the conference.

References

[1] X. L. Ji, K. T. Lee, L. F. Nazar, Nature Materials
2009,
8, 500-506.

[2] J. Xiao, Advanced Energy Materials
2015,
5.

[3] Y. L. Cao, M. Li, J. Lu, J. Liu, K. Amine, Nature Nanotechnology
2019,
14, 200-207.
Anhydrous LiNbO3 Synthesis and Its Application for Surface Modification of Garnet Type Li-Ion Conductors
Authors: Mann Markus , Schwab Christian , Ihrig Martin , Finsterbusch Martin , Martin Manfred , Guillon Olivier , Fattakhova-Rohlfing Dina
Published: November 2022

In our work we demonstrate a facile, water-free synthesis of amorphous lithium niobate (LiNbO3) layers. Our developed method also enables the coating of substrates in inert atmosphere with simple, industrial scalable methods. As verification, a 120 nm thin LiNbO3 layer was deposited on the garnet type lithium ion conductor Li6.45Al0.05La3Zr1.6Ta0.4O12 (LLZTO) to improve its interface to lithium metal and reduce dendrite formation. The application of the thin film reduced the interface resistance between LLZTO and lithium metal to 1.02(13) Ω∙cm2 and was able to suppress dendrite formation for current densities of up to 0.5 mA/cm2. The chemical stability of the LiNbO3 thin film in contact with Li-metal was verified by SEM, XPS and ToF-SIMS.
(Invited) Electrocoat for Low-Cost, Water-Based Li-Ion Battery Electrode Manufacturing
Authors: Sylvester Kevin
Published: November 2022

The state-of-the-art manufacture of lithium ion battery (LIB) cathodes is slot-die coating of a high viscosity slurry consisting of active materials, conductive additives, and a polymeric binder in N-methyl-2-pyrrolidone (NMP). The operation of slot-die is costly due to the 2-coat/2-cure electrode processing and the use of NMP solvent, which is an expensive consumable with serious health concerns. An alternative approach is the use of waterborne binder systems applied to metal foils using electrocoat. Electrocoat is an electrophoretic process widely recognized to be a high-throughput, low cost, coating application method that allows simultaneous coating of both sides of metal. This presentation will demonstrate the development of novel binders to enable electrodeposited lithium-ion battery electrode coating system. The novel binders were designed for flexibility, ionic mobility, and compatibility with high-energy density active materials and formulated to result in stable water-based cathode coating systems.
What Is Important? Effect of Primary and Secondary Particle Size
Authors: Chung Woowon , Shim Jinha , Bang Jin Ho
Published: November 2022

High nickel layered oxides are attractive cathode materials that can achieve high energy density in lithium-ion batteries (LIBs). Many researchers have strived to improve the cycling stability and energy density of LiNiO2 (LNO) through another metal mixing, dopping, or coating method. However, the particle size effect of pure LNO during the charging/discharging system has not been fully understood yet. Many computing research results revealed that smaller-particle materials with highly connective interfaces and reduced diffusion paths exhibit higher rate performance and good cycling stability than bulk counterparts. However, our study revealed that the different particle size of LNO has a very different trend in contrast to the computation results because they overlooked the influence of primary particles. In this study, we focus on the impact of the particle size distribution of spherical cathode material on positive electrodes in LIBs. We designed four different particle sizes of Ni(OH)2 by controlling pH, time, and agitation speed. When the other conditions were the same except for the particle size, we were able to explore how the grain size, Li off-stoichiometry (Li1-zNi1+zO2), and activation energy affect the battery performance. Through size comparison, a better understanding of the influence of particle size distribution was obtained, which would be an important basis to engineer electrodes for higher C-rate capability, higher performance, and better stability during battery cycling.
Silicon Nanowires Grown on a Stainless Steel Fiber Cloth: A Flexible and Robust Anode for Lithium-Ion Batteries
Authors: Imtiaz Sumair , Amiinu Ibrahim Saana , Storan Dylan , Kapuria Nilotpal , Geaney Hugh , .Kennedy Tadhg , Ryan Kevin
Published: November 2022

Silicon nanowires (Si NWs) are a promising anode material for lithium-ion batteries (LIBs) due to their high specific capacity [1]. Achieving adequate mass loadings for binder-free Si NWs is restricted by low surface area, mechanically unstable and poorly conductive current collectors (CCs), as well as complicated/expensive fabrication routes [2][3]. Herein, a tunable mass loading and dense Si NW growth on a conductive, flexible, fire-resistant, and mechanically robust interwoven stainless-steel fiber cloth (SSFC) using a simple glassware setup is reported. The SSFC CC facilitates dense growth of Si NWs where its open structure allows a buffer space for expansion/contraction during Li-cycling. The Si NWs@SSFC anode displays a stable performance for 500 cycles with an average Coulombic efficiency of >99.5%. Galvanostatic cycling of the Si NWs@SSFC anode with a mass loading of 1.32 mg.cm−2 achieves a stable areal capacity of ≈2 mAh.cm−2 at 0.2 C after 200 cycles. Si NWs@SSFC anodes with different mass loadings are characterized before and after cycling by scanning and transmission electron microscopy to examine the effects of Li-cycling on the morphology. Notably, this approach allows the large-scale fabrication of robust and flexible binder-free Si NWs@SSFC architectures, making it viable for practical applications in high energy density LIBs.

Figure 1.

Areal capacity vs cycle number of Si NWs@SSFC with mass loadings 0.24 and 1.32mg.cm–2 at C/5

References

[1] Y. Jin, B. Zhu, Z. Lu, N. Liu, J. Zhu, Adv.
Energy Mater., 7 (2017), 1700715

[2] T. Kennedy, M. Brandon, K. M. Ryan, Adv.
Mater., 28(2016), 5696

[3] T. D. Bogart, D. Oka, X. Lu, M. Gu, C. Wang, B. A. Korgel, ACS Nano, 8(2014), 915

Figure 1
(Digital Presentation) Synthesis and Characterization of ZIF-8@ZIF-67 Bimetallic MOF for Supercapacitor Applications
Authors: Sundriyal Mansi , Sundriyal Shashank , Shrivastav Vishal , Deep Akash , Tiwari Umesh kumar
Published: November 2022

Metal-organic frameworks (MOFs) are the attractive materials for energy storage applications because of its distinctive properties like high porosity, structural flexibility, high specific surface area, good stability etc. However, their low conductivity motivates to incorporate with some conductive matrix in a way to produce conductive and porous composite. Herein, we have synthesized Zeolitic imidazolate frameworks (ZIFs)-based core–shell structured nanomaterials. The bimetallic MOF consisting of ZIF-8@ZIF-67 core-shell structure is synthesized and the formation of ZIF-8@ZIF-67 structure is further confirmed by XRD, Raman, FTIR, BET and FESEM characterizations. The as prepared electrode material shows very high specific surface area and hierarchical porous morphology, therefore becomes suitable to be used as an active electrode material for supercapacitors application. Furthermore, the ZIF-8@ZIF-67 shows superior electrochemical performance using 1M Na2SO4, Redox electrolyte and water in salt electrolyte (WiSE) in a three-electrode system. The as-prepared electrode material shows high specific capacitance and long cycle life as compared to their pristine electrode counterparts. Therefore, this work paves the way for the utilization of various bimetallic MOFs to improve the conductivity of pristine MOFs in a way to utilize as an appropriate electrode material for next generation energy storage devices.

Keywords: ZIF, Water in salt electrolyte, Porosity, Redox electrolyte, Supercapacitor
(Digital Presentation) Engineering Electrode Architecture and Interfacial Chemistry of High-Content, High-Loading Silicon Anodes to Improve Cycle and Calendar Life
Authors: Carroll Gerard (MIke) Michael , Doeren Ryan , Urias Fernando , Schulze Maxwell , Neale Nathan R.
Published: November 2022

Silicon lithium alloys (SiLix) as the anode active material in a Li-Ion battery configuration offers possible energy densities paralleled only by pure lithium metal. However, the extreme mechanical deformation of alloying and dealloying SiLix through charge/discharge cycles paired with the highly reactive interface of SiLix are large barriers to industrial adoption of high-silicon-content negative electrodes. Moreover, these challenges are magnified when the thickness of the electrode is brought to relevant levels (>3 mg/cm2). Here, I describe efforts to address these challenges by utilizing single-nanometer-scale silicon nanoparticles to reduce capacity fade related to mechanical failure. I also detail new interfacial chemistries which give rise to precise electrode-level engineering in which the SEI morphology and thickness can be controlled. This development has enabled a 75% by mass silicon composite electrode to achieve cycle capacity retention of 73% through 1000 charge/discharge cycles against capacity-matched NMC-based cathodes.

Figure 1
Enhanced Structural Stability and Capacity Retention of Ni-Rich LiNi0.91Co0.06Mn0.03O2 Cathode Material By Dual Doping and Coating for Libs
Authors: Kim Hyun-Soo , Sattar Tahir , Sim Seong-Joo , Seo Myungsu , Jin Bong-Soo
Published: November 2022

Nickel-rich layered cathode material has been received a lot of attention due to their superior cycle-ability, high energy density and improved safety. However, there are some issues which are needed to be resolved to ensure the long term application. The hostile attack of electrolyte with the charged cathode electrode results in the growth of thick solid electrolyte interphase (SEI) at the expense of Li+ consumption and increase in interfacial resistance. In addition, de/intercalation of Li+ leads to the continuous contraction and expansion of lattice structure that leads to the crack formation in the active material particles during extended cycling.

In this work, a facile technique has been adopted to resolve the mentioned problems. In this study, Li3BO3 has been coated on the NCM surface to protect the active material against the continuous attack of electrolyte and boron is doped to enhance the structural stability of LiNi0.91Co0.06Mn0.03O2 NCM cathode material. The samples were characterized by XPS, XRD, SEM and TEM and the electrochemical properties were measured by assembling the coin cells. The XRD results confirm the shifting of (003) diffraction peak towards low angle which validates the boron doping in the crystal structure. The presence of B1s is confirmed on the surface of modified NCM by XPS analysis. The FETEM images shows a uniform and distinct coating layer of 12 nm on the surface of 0.05 wt% coated NCM. The 0.05 wt% NCM samples offers the highest discharge capacity of 215.3 mAh g-1 at 0.1C and capacity retention of 81.6% at 0.5C (1C = 202 mA g-1) after 100 cycles. The reason behind enhanced cycling is the high bond dissociation energy of B−O (ΔHf298 = 402 kJ mol−1) than Ni–O (ΔHf298 = 391.6 kJ mol−1), Co–O (ΔHf298 = 368 kJ mol−1) and even Mn–O (ΔHf298 = 402 kJ mol−1). Even at 2C cycling, LBO-0.05 NCM sample demonstrated a capacity retention of 79.4% after 100 cycles while pristine shows only 67.3%. The modified samples displayed superior rate performance as compare to pristine NCM, especially at high current density. The cyclic voltammetry and EIS results are in-line with the cycling data. The presence of B3+ doping in host structure and Li3BO3 coating on the NCM surface results in the superior electrochemical performance of modified NCM.
MoS2—Carbon Materials Composite with Dual Phase of MoS2 and Their Application for Anode of Lithium Ion Battery
Authors: Jang Kyuyeon , Lee Yeong A , Yoon Hana
Published: November 2022

Carbon materials such as graphite, graphene, and CNT are mainly used as anode materials for LIBs because of their wide surface area and excellent stability in Lithium Ion Battery operation. However, graphite, which is mainly used as an anode material, has a very low theoretical capacity of 372 mAh/g. As high-capacity LIBs are increasingly needed like electric vehicles, many studies are being conducted to increase LIB capacity. For example, research on Si anode materials is attracting attention, and Si has a high theoretical capacity of ~4200 mAh/g. However, since there is a fatal disadvantage of volume expansion in cycle performance, stability can be a major defect in the driving condition of LIB.

Transition Metal Dichalgogenides (TMD) materials are attraction a lot of attention as various energy materials such as HER and ORR as well as LIB. Their structural characteristics, low price, and high capacity in terms of energy storage make them very attractive to study as a new anode material for LIB batteries. MoS2 belonging to the TMD material is known to have a theoretical capacity of 670 mAh/g. In particular, MoS2 has a single layer structure, and this single layer structure is coupled by weak van der walls force. These properties are very advantageous for exfoliating MoS2 to form a layer-by-layer form with other materials. MoS2 is known to have a typical 1T, 2H structure. However, MoS2, which exists in a stable phase, generally has a 2H structure and has semiconducting properties. Therefore, it is less conductive than graphene, which can be an obstacle to being used as an anode. MoS2 is known to have a typical 1T, 2H structure. However, MoS2, which exists in a stable phase, generally has a 2H structure and has semiconducting properties. Therefore, it is less conductive than graphene, which can be an obstacle to being used as an anode. 1T structure is known to have very good conductivity because it has conductive properties. Therefore, when used as an anode, it has many advantages in that it has conductivity, but since it is a metastable structure, it can be converted to 2H very easily, so it is not easy to maintain the structure.

In this study, the synthesis of MoS2 and graphene composites was performed in one pot using a chemical exfoliation method. In addition, it was possible to stably maintain the metastable 1T structure of MoS2 by using graphene as a support material through a post-treatment process in this process. The diffusion of Li+ was promoted by having a 1T structure with a wide interfacial spacing and high conductivity, and superior conductivity and high capacity were stably maintained compared to a composite having a 2H single phase. Through this, a stable and high-capacity anode material was realized using the high energy storage capacity of MoS2 and the stability of graphene.
Parasitic-Reaction-Triggered Performance Deterioration of Long-Term Cycling Nickel-Rich Cathodes
Authors: Cai Jiyu , Chernova Natasha A. , Prevel Brad , Wang Feng , Chen Zonghai
Published: November 2022

Ni-rich LiNi1-x-yMnxCoyO2 (NMC, x+y < 0.5) materials are widely regarded as the promising cathodes for high-energy-density and cost-effective lithium-ion batteries. Cycling performance deterioration is a long-standing challenge for Ni-rich NMC, especially at high potentials (>4.3V vs. Li/Li+). The fundamental understanding of failure mechanisms is crucial for the development of long-life lithium-ion technologies. In our investigation, full cells cycled to 4.35 V for 1000 cycles lose about 49% of their initial capacity, while the counterparts cycled to 4.15V lose only 27% of their initial capacity after 1000 cycles. The relatively low capacity loss of the low voltage cells (4.15 V) is dominated by the impedance hike, while the drastically increased (more than half of) capacity loss of high voltage cells (4.35 V) is contributed from the irreversible degradation of the electrode materials. The post-mortem diagnosis suggests that parasitic reactions are the primary driving force for severe deteriorations, including the irreversible phase transformation. The generally concerned transition metal dissolution and bulk phase transformation negligibly make direct contributions to the severe capacity loss, but the loss of active cathode materials has some substantially detrimental impacts on irreversible capacity loss. Our findings emphasize that mitigating parasitic reactions is crucial for enabling long life of Ni-rich cathodes.

Figure 1
Research for Electrochemical & Structural Properties of Recycling Cathode Materials for End of Life Lib
Authors: Park Sangho
Published: November 2022

Demand for lithium-ion batteries (LIBs) has increased dramatically over the years due to the rapid market expansion of electric vehicles. However, many of the essential components of cathode materials, such as cobalt, nickel, manganese and lithium, are resource-limited and expensive[1]. Therefore, recycling of used LIB cathode materials is very important to conserve resources and the environment. Currently, the lithium secondary battery recycling technology mainly uses wet and dry smelting, but there is a disadvantage of high energy consumption due to the use of strong acid and the smelting process[2-3].

In this study, the cathode active material was separated from a pouch-type lithium secondary battery separated from a portable tablet that was over 10 years old and the chemical, structural, and electrochemical characteristics thereof were investigated. The cathode active materials were dismantled from a pouch-type LIB, which was removed from the tablet produced in 2011. The pouch cell was in a swelling state and the OCV was 0V due to internal short is expected. As a result of TGA analysis, the electrode composition was confirmed to be 92wt% of the cathode active material, 3wt% of the conductive agent, and 3wt% of the binder, respectively. The recovery rate of the active material is the best when a mixed solvent including NMP, heating, and ultrasonic, respectively. Through SEM and EDS analysis, copper metal due to dissolution of the negative electrode current collector was found on the surface of the positive electrode. As shown in Fig. 1, It can be seen that the positive electrode active material recovered using the composite solvent is a positive electrode active material that is a mixture of NCM active material and LMO active material. The XRD results shows a well layered structure and a Co3O4 phase due to lithium deficiency. In order to examine the electrochemical characteristics of the recovered electrode, it was reassembled into a 2032 coin type cell and evaluated, and the discharge capacity of approximately 150mAh/g was recovered as shown in Fig. 2. The positive active material recovered according to the experimental results is estimated to be in a state of insufficient lithium, and a lithium compensation process is planned to be additionally performed in the future.
Data-Driven Direct Diagnosis of PV Connected Batteries
Authors: Dubarry Matthieu , Costa Nahuel , Matthews Dax
Published: November 2022

Photovoltaic systems are providing a growing share of power to the electric grid worldwide. As more and more of these systems are tied with battery energy storage to balance their intermittency, being able to ensure long and safe operation of these batteries will become critical. Because of their sporadic usage, far from the typical constant current or constant power, diagnosability without having to perform lengthy maintenance cycles will be a key factor to accelerate deployment.

This work proposes a new methodology to enable the training of machine learning algorithms so they could be applied directly to photovoltaic (PV) battery charging data for opportunistic diagnosis. This is done by training the algorithms on synthetic voltage data under different degradations calculated from clear-sky model irradiance data. Validation was performed on synthetic voltage responses calculated from plane of array irradiance observations for a PV system located in Maui, HI, USA.

Herein, we will present the result of our proof-of-concept study where we investigated the diagnosability of the voltage response of PV charged batteries under 18 different cloud coverages scenarios and for more than 10,000 different degradations. We also evaluated the effect of training conditions on clear-sky irradiance data by analyzing the resulting differences from training on 700,000 different voltage curves for a single day vs. 45,000 different voltage curves for of each of the 18 days used for cloud coverage estimation. In addition, we considered and quantified the effect of cell-to-cell variations. Training was performed on five state-of-the-art machine learning algorithms for battery diagnosis which included decision tree ensemble methods and neural networks. Finally, because the diagnosis was done outside of constant current, the capacity- and time-based information were decorrelated and compared. While time-base diagnosis is the most interesting for deployed systems, it was shown to be less accurate than its capacity counterpart for the tested algorithms. Yet, the accuracy of the diagnosis is still satisfactory for days where cloud effect is limited (average RMSE of 2.5% compared to 1.3% for capacity based if 50% or more clear skies).

Summarizing, we will show that the degradation of PV-connected batteries could be diagnosed opportunistically without the need for maintenance cycles using well-trained state-of-art machine learning algorithms. Calculated RMSEs were below 2% for days with 50% or more clear skies considering more than 10,000 different degradation paths with 25% or less of the three thermodynamic degradation modes. In addition to the results themselves, and before real PV battery degradation data becomes available, this work is showing the significant benefits of using synthetic data to understand the expected variations and to start preparing adapted tools for when data become available.
Operando Quantification of Solution Li+ in Li-Ion Batteries
Authors: Dawkins Jeremy , Danis Andrew , Beaulieu Isabelle , Chhin Danny , Mirolo Marta , Martens Isaac , Schougaard Steen , Mauzeroll Janine
Published: November 2022

What if you could see inside a Li-ion battery while you operate it? This is the concept behind “operando” methodologies which allow researchers to experimentally observe fundamental processes that occur within batteries during charge and discharge.

Our team recently developed a new methodology employing synchrotron X-ray fluorescence and X-ray diffraction simultaneously. This method provides crucial information about mass transport limitations in both the solid and solution phase of Li-ion batteries which was previously unavailable. This new method can 1) validate the predictive power of established P2D battery models, 2) conclusively quantify complex transport mechanisms in structured electrodes and 3) fundamentally change the approach to the rational design of new electrode architectures.
DFT Studies of Catalytic Activity of Rutile Typed Metal Oxide (110) Surface in Sodium-Air Batteries
Authors: Ngoepe Phuti Esrom , Ngobeni Peter , Maenetja Khomotso Portia
Published: November 2022

Metal-air batteries, such as Li-air, have been extensively studied owing to their high theoretical energy density, which is up to three times that of the conventional to Li-ion batteries and interest in Na-air is now emerging [1,2, 3]. The current study is providing a better understanding of the catalytic activity of rutile typed MO2 (MnO2, TiO2 and VO2) for the oxygen reduction and oxygen evolution reactions in Na-air batteries, using density functional methods. When oxygen is adsorbed at the Na/MO2 (110) surface different clusters, such as superoxide, peroxo on Na/M, and dissociated configurations are formed. Our current study has demonstrated that MnO2, as a catalyst, promotes nucleation and growth of both Na2O and Na2O2. On the contrary, other metal oxides such as TiO2 and VO2 do not depict this catalytic effect towards the formation of discharge products in Na-O2 batteries. Furthermore, it can be deduced from our calculated electronic properties, in the form of an intercept of the density of states (DOS) by the Fermi level, that Mn catalyzed configurations are more stable than those based on Ti and V. It can therefore be surmised that the MnO2 catalyst supports the formation of NaO2 which is the most stable discharge product in Na-air batteries. Furthermore, the surface NaO2 appears to have bond lengths comparable to those of the bulk and monomer NaO2.

References:

[1] M. Park, H. Sun, H. Lee, J. Lee and J. Cho, Adv. Energy Mater. 2012, 2, 780.

[2] K.P. Maenetja, P.E. Ngoepe, J. Electrochem. Soc. 2021, 168, 070556

[3] Y. Kang, Y. Mo, S. P. Ong and G. Ceder, Nano Lett. 2014, 14, 101
Evaluating Kinetics of Composite Cathodes of All-Solid-State Batteries
Authors: Minnmann Philip , Bielefeld Anja , Ruess Raffael , Burkhardt Simon , Dreyer Sören L. , Trevisanello Enrico , Adelhelm Philipp , Richter Felix H. , Strauss Florian , Brezesinski Torsten , Ehrenberg Helmut , Janek Jürgen
Published: November 2022

ASSBs (all-solid-state batteries) are promoted as an energy dense and safe alternative to current Li-ion batteries (LIBs) and attract great interest from academia and industry. In contrast to LIBs, which employ a liquid organic electrolyte, they utilize a solid electrolyte. This substitution promises to eliminate the flammability of the battery and to simplify the cell design.

While recent research efforts have concentrated on miniaturizing and eventually even removing the anode host material in batteries, the relative portion of the cathode needs to be maximized, as cathodes are the only component that can increase energy density by increasing its fraction. In a simplified view, the cathode kinetics are determined by the cathode microstructure, the volume fractions of the constituents and the properties of electrolyte and cathode active material (CAM).

Liquid electrolytes can easily penetrate porous composite cathodes, but rigid SEs can not do the same, resulting in residual porosity in the cathode. This porosity can lower active interface area between CAM and SE, and increase tortuosity of ionic and electronic charge transport pathways. Sufficient ionic and electronic transport pathways in composite cathode structures are, however, essential because cathode active material particles that are either electronically or ionically isolated cannot contribute to the charging or discharging process.

We analyse the requirements for SSB cathodes and determine charge transport bottlenecks by impedance spectroscopy of a reference system consisting of a thiophosphate based solid electrolyte and a nickel rich layered CAM. Different cathode microstructures are analysed and their charge transport properties are quantified as partial conductivities. From the obtained partial conductivities, we calculated tortuosity factors and correlated them to cell performance with complementary cycling data of all-solid-state batteries in order to determine charge transport bottlenecks. We find, that ionic charge transport and consequently cathode kinetics are highly dependent on the SE particle size distribution

In addition, we analyse the requirements for CAMs for SSBs and develop design principles for different CAM types that aim to further increase cathode performance.
Enabling Si-Dominant Anodes with Focus on Binder
Authors: Kloker Gabriele , Vrankovic Dragoljub , Frey Martin , Anjass Montaha
Published: November 2022

Since current chemistries in lithium ion batteries (LIBs) including graphite anode reached their energy density limits, a promising candidate on anode side is the abundantly available silicon with its enormous capacity, but showing several failure mechanisms based on its extensive swelling (>300%). This leads to excessive solid electrolyte interphase (SEI) formation and electrode delamination during cycling, which can be reduced by the modification of the active material itself, e.g. carbon-embedded silicon (Si/C), but still these materials show the same failure mechanisms in a less pronounced manner. Regarding the costs and availability, the next generation anode is desired to be based on metallurgical silicon, where one promising path to enable Si-dominant anodes is the design of advanced binder systems to maintain a stable network around the active material during cycling. However, in most studies new binders are mainly tested in electrodes with low active material content and low loadings while lacking of full cell data, which makes it impossible to estimate the capability and influence of the binder to mitigate the failure mechanisms in full cell operation.

In this work, several modifications of the binder are combined with commercial Si/C material and bare micro-sized silicon with 100% silicon as active material. The electrodes are tested in half coin cells and small full pouch cells with ~60 mAh capacity. To examine the performance in detail and understand the underlying failure mechanisms, post-mortem analysis was conducted.

The already commonly used polyacrylic acid (PAA) can be further adapted to the respective anode active material (AAM) via partial neutralization with e.g. LiOH to tune the interaction with the AAM and reduce the first cycle losses due to the reaction of the carboxylic groups with lithium. Nevertheless, the influence of PAA/LiPAA on the failure mechanisms and maintenance of the electrode, especially on full cell basis, are not yet fully understood. In this work, the effect of the partial neutralization on the full cell performance of a NMC811-Si/C cell is shown with the anode consisting of 91.5% Si/C material, 8% binder and 0.5% conductive additive (single-wall carbon nanotubes SWCNTs). The full cells show 3.5% higher FCE with 70% neutralized LiPAA in comparison to acidic PAA in the anode, while maintaining the same cycle life.