bluuebunny/crossref_metadata_2025 huggingface dataset:
(Digital Presentation) Approaches of Pre-Lithiation on Si Anode for Lithium-Ion Batteries
Authors: Wang Lei , Hu Jiazhi , Li Wei , Balogh Michael P
Published: September 2023

Silicon is one of the most attractive anode materials for next generation high-capacity lithium-ion batteries (LIBs) due to its high specific capacity. However, the large volume change (up to 300%) of silicon during lithiation/delithiation process leads to coupled mechanical and chemical degradation, such as pulverization of silicon particles, formation of unstable solid-electrolyte interphase (SEI), and loss of electrical connectivity, resulting in high irreversible capacity loss and rapid capacity fading. Pre-lithiation is one of the effective approaches to compensate for the loss of active lithium and extend battery cycle life.

In this work, various approaches of pre-lithiation for Si electrodes are systematically studied and compared. Different levels of pre-lithiation dosage are applied to the Si electrodes and the pre-lithiated Si electrodes are evaluated in NMC622/Si full cell configuration. After pre-lithiation, the cell capacity and cycling stability are significantly improved. The impacts of operating voltage window, and N/P ratio on electrochemical performance are also investigated. The morphology of pre-lithiated Si electrodes before and after cycling are also compared via cross section scanning electron microscopy (SEM) to understand the electrode expansion and SEI formation/growth during cycling.
(Digital Presentation) Ex Situ Electrochemical Pre-Lithiation of Silicon for Lithium-Ion Battery Anodes
Authors: Cain Jeffrey David , Hood Zachary D. , Adhikari Shiba , Moylan Thomas , Pieczonka Nicholas
Published: September 2023

Crystalline silicon as an anode material for lithium-ion batteries (LIBs) has a theoretical capacity greater than 3600 mAh/g, an order of magnitude larger than the current anode materials of choice, graphite (~370 mAh/g). However, the use of silicon is hampered by several issues that hinder its widespread usage in LIBs. Chief among these is the large volume expansion that accompanies lithiation (>300%), which results in the self-pulverization of silicon during cycling and the degradation in stability and performance that accompanies it. Silicon also suffers from active lithium loss in its first cycle from the formation of Li
x
Si and the solid-electrolyte interphase (SEI), which irreversibly consumes lithium and decreases gravimetric/volumetric capacity (typically >20% capacity loss after the formation cycle). This capacity loss coupled with mechanical and chemical degradation leads to poor capacity retention and short cycle life. Pre-lithiation of silicon and other potential anode materials (e.g. SiOx), a process of inserting additional Li into Si prior to battery operation, is thus desired to compensate for lithium consumption and to maintain the high capacity associated with silicon. Here, we demonstrate a simple and scalable method for the ex situ (i.e. outside the cell) electrochemical synthesis of pre-lithiated silicon. In this method, a current is driven though an electrochemical stir-tank reactor composed of Si powder in electrolyte suspension and a Li containing anode. When Si particles contact the conductive inner surface of the reaction vessel, lithium ions in the electrolyte are reduced on the surface to form lithium-silicon compounds. The degree of lithiation is controlled by the applied current density, applied voltage, and/or runtime. This talk will describe the chemical and structural characteristics of pre-lithiated silicon synthesized with this technique, basic electrochemical properties of our lithiated material, and the specific advantages presented by the method vs other methods.
Micro-Architected Lithium Cobalt Oxide Electrodes Via Hydrogel Infusion Additive Manufacturing
Authors: Sun Yuchun , Greer Julia R.
Published: September 2023

Additive manufacturing frees up the structural design of battery electrode materials from traditional slurry electrodes, enabling three-dimensional free-standing structures with micro-architected features, which provides a promising pathway toward 3D solid-state batteries with high power and high energy density. In this work, lithium cobalt oxide (LCO) is fabricated into 3D micro-lattice through a novel hydrogel infusion additive manufacturing (HIAM) process. A blank 3D architected organogel is fabricated through photopolymerization-based 3D printing and soaked in water to form a blank hydrogel micro-lattice, where lithium and cobalt ions in an aqueous solution are then swelled into the hydrogel. A free-standing LCO micro-lattice is synthesized from the ion-containing hydrogel during the post-printing calcination process. 50 μm beam diameter is obtained, giving a crucial lithium-ion diffusion length of 25 μm into LCO lattice beams. Structural, electrochemical, and mechanical properties of the LCO microlattice are investigated. HIAM technique utilizes photopolymerization of a UV-curable photoresin to create 3D structures with well-controlled form factors. Compared to traditional extrusion-based additive manufacturing techniques, photopolymerization stands out for its ability to fabricate materials with higher resolution. The main challenge with photopolymerization to fabricate non-polymeric functional materials is the complex photoresin design. A standard approach is to introduce active material nanoparticles into the photoresin, which often sacrifices print resolution due to the presence of light-scattering nanoparticles. HIAM technique overcomes the difficulties during the resin design by using a single photoresin to fabricate a large variety of functional materials. Without presence of nanoparticles, even higher resolution can be achieved. With this technique, LCO cathodes can be flexibly architected into 3D geometries for optimization of their electrochemical performance. It also enables the fabrication of various electrode materials into 3D structures with well-controlled form factors, and their incorporation into customizable batteries and microbatteries of any shape.
Safety Evaluation of Temperature-Dependent Aging Mechanisms of Li-Ion Batteries Using ARC Tests with Multiple Online Sensors
Authors: Feinauer Max , Abdellatif Abdelaziz , Sichler Peter , Wohlfahrt-Mehrens Margret , Waldmann Thomas
Published: September 2023

Compared to many other characteristics of Li-ion batteries, the safety behavior is a critical property and should be examined carefully. Especially manufacturers and most studies only focus on the safety of pristine cells. However, the safety behavior can drastically change dependent on the prior aging conditions such as ambient temperature. Especially low temperature aged cells with Li plating show a drastically decreased safety behavior [1]. Moreover, cells aged at higher temperatures with a distinct solid-electrolyte-interface (SEI) layer on the anode show an increased onset of self-heating leading to improved safety [2]. Post-Mortem analysis of aged cells confirmed the two dominating aging mechanisms: Li plating and SEI growth for low and high temperature range, respectively.

Heat-wait-seek (HWS) tests under quasi-adiabatic conditions in an accelerated rate calorimeter (ARC) are a well-known method to evaluate the safety behavior of Li-ion batteries and can reveal critical temperatures such as the onset of self-heating. HWS tests on cells aged at different temperatures until different state-of-health (SOH) reveal the trend that a more pronounced aging increases or decreases the onset of self-heating depending on whether SEI growth or Li plating is the dominating aging mechanism.

In addition to the temperature measurement, multiple sensors for voltage, resistance, strain, and ultrasonic transmission and reflection were placed on the pouch cell for a better understanding of the ongoing processes while the HWS tests. The benefit of these sensors is that they are cheap, allowing them to be widely implemented. Furthermore, an externally coupled mass spectrometer provides information about the gases produced and released after venting of the cell [3]. By Correlating different sensors signals, critical events on the way to the thermal runaway can be reliably identified or even predict in an early stage.

Hence, the HWS tests on Li-ion batteries aged at different temperatures in combination with the multi sensor study provide a comprehensive understanding of the influence of temperature dependent aging state on the safety behavior of Li-ion pouch cells.

Acknowledgment

We gratefully acknowledge the German Federal Ministry of Education and Research (BMBF) for the financial support of the projects AnaLiBa (03XP0347C) and MiCha (03XP0317C) within the AQua cluster.

References

[1] T. Waldmann, M. Wohlfahrt-Mehrens, Electrochimica Acta 230 (2017) 454–460. https://doi.org/10.1016/j.electacta.2017.02.036.

[2] M. Börner, A. Friesen, M. Grützke, Y.P. Stenzel, G. Brunklaus, J. Haetge, S. Nowak, F.M. Schappacher, M. Winter, Journal of Power Sources 342 (2017) 382–392. https://doi.org/10.1016/j.jpowsour.2016.12.041.

[3] A.A. Abd‐El‐Latif, P. Sichler, M. Kasper, T. Waldmann, M. Wohlfahrt‐Mehrens, Batteries & Supercaps 4 (2021) 1135–1144. https://doi.org/10.1002/batt.202100023.

Figure 1
Lead-Free Ferroelectric Ba0.9Sr0.1TiO3 Coupled Polysulfide Trapping on Sulfur Cathode in Stable and High Energy Density Lithium-Sulfur (Li-S) Batteries
Authors: Castillo Ivan , Mishra Karuna K. , Dorvilien Valerio , Tripathi Balram , Rivera Del Valle Jean , Katiyar Rajesh , Katiyar Ram S.
Published: September 2023

In the present work we are reporting electrochemical performance of Lead-free ferroelectric Ba0.9 Sr0.1TiO3 (BST), a high polarization (~14.58 μC/cm2
) material, to assist polysulfide chemisorption via their permanent dipoles. The performance of fabricated cathodes in terms of structural, electronic, morphological, and electrochemical characteristics have been carried out with various concentrations of ferroelectric inclusion. X-ray diffraction analysis revealed tetragonal symmetry (c/a=1.0073) and the Raman spectroscopic studies confirmed A1(TO1), A1(TO2), A1(TO3) and A1(LO3) optical modes of the tetragonal phase of the BST modified composites. All the compositional cations were observed in SEM-based EDAX analysis, confirming homogeneous distribution of BST in the sulfur cathode system having grain sizes of ~ 1-1.5 μm. The porosity in the composites were found to be negligible based on the microscopic analysis. Considering that polar substances have good affinity towards trapping polysulfides and that can provide more stable reacting environment in the cathodic site, ferroelectric BST was employed to trap such polysulfide intermediates due to possessing permanent dielectric polarizability. With the spontaneous polarization induced by composite structure, ferroelectric material provides internal electric fields and increase chemisorption with the reactive heteropolar material. Thus, BST coupled C-S composite cathodes improved the electrochemical performance in comparison with the cathodes composed of only C-S. A stable high capacity of 1200 mAh/g was achieved for the BST coupled C-S cathodes in contrast to 700 mAh/g in pristine C-S cathode, due to reduction in polysulfides migration influence by the electric field of the BST ferroelectric. Two plateaus were observed, namely at 1.5 V and 3 V in the charge/discharge characteristics. The detail results will be presented at the ECS meeting 2023.
Cqds@S/SWCNTS Composite Cathodes and Ferroelectric Coated Separator an Accelerating Agent of Li- Ions for High Performance Li-S Batteries
Authors: Katiyar Rajesh , Zuluaga Gomez Claudia C. , Castillo Ivan , Tripathi Balram , Morell Gerardo , Weiner Brad R , Katiyar Ram S
Published: September 2023

In this work, we are reporting capacity retention for CQDs@S/SWCNTs composite cathode achieved a room temperature ferroelectric material of Bi0.925Gd0.075Fe0.95Ni0.05O3 (BGFNO) with high remanent polarization coated separator as Li-ion accelerating agent for high performance Li-S batteries. We synthesized mechanochemically composite cathodes using sulphur, SWCNTs and CQDs. The ferroelectric coated separator was used along cathode side for Li-ion diffusion and tested @ 200 mAg-1. The observed capacity retention of 650 mAhg-1 /460 mAhg-1 upto 100 cycles. Strong chemical binding effects due to ferroelectric coating on separator towards polysulfides and fast ion transport are achieved for the CQDs @ S/SWCNTs cathodes. While S/SWCNT composite cathode samples with and without coated BGFNO on separator tested @200mAg-1 constant current. The observed capacity ~635 mAhg-1/378 mAhg-1 and ~400 mAhg-1/ 330 mAhg-1 upto 50 cycles. Our results show higher capacity of the CQDs@S/SWCNTs upto 650 mAhg-1 for composite cathode attributes shuttling of polysulfides and stability for high current density in terms of cycle stability, rate performance and charge-discharge characteristics.
High-Capacity Metal Oxide Electrodes for Lithium-Ion Batteries
Authors: Katiyar Ram S. , Oli Nischal , Florez Gomez Jose Fernando , Zuluaga Gomez Claudia , Katiyar Rajesh , Wu Xianyong , Morell Marrero Gerardo
Published: September 2023

It is of paramount importance to develop rechargeable lithium-ion batteries (LIBs) with higher energy to meet the demands of emerging energy storage applications. Currently, LIBs use LiCoO2 as the cathode and graphite as the anode, which shows moderate capacity of ~140 mAh g-1 and ~350 mAh g-1, respectively. As a result, the energy density is limited to 120-160 Wh kg-1. In this context, we have investigated a layered-spinel material (Li2MnO3, LiMn2O4, LiNi2/3Mn1/6Co1/6O2, NMC 811,LiFePO4) as a high-capacity cathode. This cathode exhibits a theoretical capacity of ~ 250 mAh g-1, and in our preliminary work, we demonstrated a high capacity of ~ 250 mAh g-1. We also find that this cathode shows high voltage of 4.5 V and stable cycling over 50 cycles. On the anode side, we investigated BiFeO3(BFO) as a potential high-capacity anode, which delivers a high capacity of ~750 mAh g-1, double the capacity of graphite. In the following research, we will explore the possibility of assembling Li-ion full cells using these two materials in order to demonstrate high energy density.

The Li-ion storage mechanism in these two materials will also be thoroughly investigated by electrochemical and physical characterizations, such as electrochemical impedance spectroscopy (EIS), ex-situ XRD, and X-ray photoelectron spectroscopy.
High Performance Anode-Free Lithium Pouch Cells Employing Lithiophilic Gel Polymer Electrolyte with Ion Conductive Network
Authors: Roh Jin-Ah , Ban A-Hyeon , Kim Hyo-geun , Bae Woo Jin , Woo Hyunsik , Moon Jongseok , Kim Dong-Won
Published: September 2023

Anode-free lithium metal batteries have recently emerged as a next generation battery due to increased energy density by adopting bare current collector as an anode without excess lithium source. However, lithium tends to grow in uncontrolled dendritic form when depositied on a heterogeneous current collector, which eventually leads to low coloumbic efficiency and poor life span of the battery. Recent studies have attempted to apply artificial solid electrolyte interphase (SEI) on the current collector to solve theses problems. PEO-based polymeric artificial SEI is commonly used due to high lithium ion conductivity and flexiblility, but its weak physical properties limit its practical application. Herein, we report a chemically cross-linked poly (ethylene glycol) diacrylate (PEGDA)-based gel polymer electrolyte containing AgNO3 as Li nucleation seed for uniform Li deposition. It guides uniform Li-ion flux at the electrode/electrolyte interface and provides mechanical strength to suppress lithium dendrite growth. The gel polymer electrolyte was applied to anode free pouch cell and its cycling performance was investigated in the voltage range of 3.6 - 4.3 V at 0.5 C rate. Our results demonstrate that the proper combination of electrolyte and current collector can increase the conversion of polymerization and achieve stable interfacial properties with electrodes, resulting in improvement of the cycle life of anode free lithium pouch cell.
Effects of Cathode Loadings on the Performance of the LiNi0.8Mn0.1Co0.1O2 Cathode in Lithium Batteries
Authors: Velasquez Kevin , Wang Xin , Meng Xiangbo
Published: September 2023

LiNixMnyCozO2 (NMCs, x + y + z = 1) represent one promising cathode material for next-generation lithium-ion batteries (LIBs) and beyond, due to their high specific capacity and low cost.1-3 The current commercialized batteries tend to utilize high loadings of cathode materials and thin Li anodes for producing higher energy densities. However, a systematic study on the effects of cathode loadings is missing. To this end, we recently conducted a comparative study on the effects of different cathode loadings on the performance of LiNi0.8Mn0.1Co0.1O2 (NMC811). The NMC811 loading ranges from 2 – 14 mg/cm2. The resultant Li||NMC811 cells were tested for their capacity retention and sustainable capacity at different C-rates. Our study revealed that the cathode loadings have remarkably affected the cell performance. With increasing NMC811 loadings, the cells are more liable to fade in their capacity, due to a faster growth of solid electrolyte interface (SEI) on NMC811 particles and thereby a more sluggish Li-ion transportation. We also noticed that the Li anode side had remarkable effects on the Li||NMC811 cells. Particularly, we demonstrated that a polymeric surface coating via molecular layer deposition could protect the Li anode from degradation and thereby sustain Li||NMC811 cells for a better performance. Therefore, we concluded that the performance of the Li||NMC811 cells suffers from the issues of both the NMC811cathode and Li anode. It is significant to address their issues simultaneously for high performance.

References:

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

[2] X.W. Wang, X.B. Meng, J.S. Park, ATOMIC LAYER DEPOSITION FOR EMERGING THIN-FILM MATERIALS AND APPLICATIONS Introduction, Journal of Materials Research 35(7) (2020) 655-655.

[3] X. Meng, X.-Q. Yang, X. Sun, Emerging Applications of Atomic Layer Deposition for Lithium-Ion Battery Studies, Advanced Materials 24(27) (2012) 3589-3615.
Revealing the Lithium Storage Mechanism of Sulfurized Polyacrylonitrile Cathode by Ex-Situ NMR and Ex-Situ Raman Spectroscopy
Authors: Weret Misganaw Adigo , Kuo Chung-Feng Jeffrey , Su Wei-Nien , Hwang Bing-Joe
Published: September 2023

Sulfurized polyacrylonitrile (SPAN) is a promising cathode material for high-performance lithium-sulfur batteries.1-3 However, fundamental insights into its molecular structure and lithium storage mechanism are yet not clearly understood. Herein, we reveal the formation of N-S and C=N-S bonds in addition to the C-S and S-S bonds using high−resolution cross−polarization/magic angle spinning (CP−MAS) solid states nitrogen-15 and carbon-13 nuclear magnetic resonance spectroscopy (15N NMR and 13C NMR). Ex-situ
13C NMR, ex-situ
15N NMR, ex-situ
7Li NMR, and ex-situ Raman studies indicate the formation of Li-C-N-Li and Li-C-C-Li bonds. Li–C and Li–N bonds increase the electron density of the conjugated heterocyclic structure and benefit lowering the charge/discharge voltage hysteresis after the second cycle. These results confirm conjugated C=N and C=C double-bonds involved in the lithium-ion storage mechanism leading to higher practical discharge capacity than the theoretical capacity of elemental sulfur.

References

Weret, M. A. et al. Mechanistic understanding of the Sulfurized-Poly(acrylonitrile) cathode for lithium-sulfur batteries. Energy Storage Materials 26, 483-493 (2020).

Weret, M. A., Su, W.-N. & Hwang, B. J. Strategies towards High Performance Lithium-Sulfur Batteries. Batteries & Supercaps 5, e202200059 (2022).

Weret, M. A. et al. Fibrous organosulfur cathode materials with high bonded sulfur for high-performance lithium-sulfur batteries. Journal of Power Sources 541, 231693 (2022).
Scalable Direct Recycling of Cathode Black Mass from Spent Lithium-Ion Batteries
Authors: Gupta Varun , Yu Xiaolu , Gao Hongpeng , Li Weikang , Chen Zheng
Published: September 2023

End of life (EoL) lithium-ion batteries (LIBs) are piling up at an intimidating rate which is alarming for the environmental health and balance. The rise of renewable technologies such as electric vehicles (EV) needs to be balanced with LIB recycling to reduce the carbon footprint, ensure sustainable development, and create a circular supply chain. LiNixCoyMnzO2 (NCM) cathode materials being a dominant chemistry in high energy LIBs makes a huge portion of this waste accumulation. Direct recycling is one of the most promising ways to turn this waste to wealth but has been limited to lab-scale due to lack of robustness, namely the tedious pretreatment required which involve toxic organic solvents. Herein, we have demonstrated a process which integrates the pretreatment and relithiation of the cathode black. Cathode material from EoL EV batteries is treated in 100g per batch operation and the regenerated cathode active material demonstrates 100% electrochemical performance recovery, with 91% yield rate, and showed promise to further scale up. No use of toxic organic solvents makes our process unique with minimal environmental impact. This process has the advantages of integration, scalability, and universality, which clears the barricade for the direct recycling to move from lab to industry scale with considerable profitability.
Redox Mediator Relithiation of End-of-Life Lithium-Ion Battery Cathode Materials
Authors: Kirwa Cyrus Kibichi , Coyle Jaclyn , Luo Hongmei
Published: September 2023

Lithium-ion batteries (LIBs) are ideal for electric vehicles and electronic devices because of their high-power density and outstanding cycle life. The need for recycled LIBs material is pivotal for the sustainability of the renewable energy industry. The recycling process needs to be both economically and environmentally conscious. Direct recycling is cheaper and generates the least amount of waste compared to pyrometallurgical and hydrometallurgical processes.

Direct recycling explored in this work is useful for reclaiming precious minerals from the End-of-Life (EOL) LIBs material. Redox mediator relithiation restores the lithium content rapidly and at low cost without sensitivity to EOL material with varying lithium deficiency. The redox mechanism relithiates EOL cathode material by shuttling charges very fast between lithium metal and EOL cathode material. The redox mediator is oxidized to create lithium rich solvent and reduced to relithiate EOL cathode material. However, the process is sensitive to pH changes. The redox reaction creates acidic solvent, which may cause lithium leaching. Therefore, use of lithium hydroxide (LiOH) to remove impurities on the surface of the EOL material and as a lithium source creates a basic solution to prevent lithium leaching and relithiate EOL material. This approach will potentially pave way for fast quality cathode material recovery at a low cost.

Figure 1
(Invited) Quantitative Measurement of the Safety Performance of Li-Ion Batteries
Authors: Kim Chisu , Perea Alexis , Rozon David , Dubé Joël
Published: September 2023

Safety is one of the essential requirements that should be taken into account and prioritized in the course of the development phases of lithium secondary batteries for any commercial applications. Even though different safety test standards exist to simulate the electric, mechanical, and thermal abuse conditions, there are only limited methods that can be used to quantify the safety performance of the cell.

This study aims to compare the quantitative measurement techniques of safety evaluation and identify the methods to define the design parameters influencing the eventual safety performance of the full cells. The nail penetration, hot box, ARC (Accelerated Rate Calorimeter) and overcharging test are performed using the pouch cells (1-3 Ah) with different cell designs and aging conditions.

It is found that hot box and nail penetration results are well correlated with the OCV (open circuit voltage) of the cells, suggesting that the OCV threshold can be used as a new quantitative indicator of the safety performance. Using this indicator, the cells having different P/E (power-to-energy ratio) designs and different electrolyte formulations are compared to identify the conditions to promote the safety performance of the cells.

Figure 1
(Invited) Overcoming Challenges in Transitioning Electroreduction of CO2 to a Deployable Technology
Authors: Kenis Paul
Published: September 2023

Since 2010, the electrochemical reduction of CO2 has evolved from a barely studied topic to one of the most active research areas in the field of electrochemistry. The need to reduce global CO2 emissions has driven the vigorous pursuit of different electrocatalysts, electrodes, and electrolyzer configurations that are able to reduce CO2 to different value added intermediates or products ever more selectively and efficiently. With many catalysts now available, attention has started to shift to topics such as catalyst stability, electrode durability, and electrolysis operation optimization. These efforts increasingly are tied to ever more-detailed techno-comic and life cycle analyses.

This presentation will provide an overview where some of these ‘beyond CO2RR catalyst discovery’ efforts are. What about durability of electrodes in different cell configurations? What should larger electrolyzer stack designs looks like, and how should they be operated to maximize performance (rate and/or selectivity)? How to optimize performance in light of dilute CO2 feeds from industrial point sources or from direct air capture, with these feeds containing different contaminants and/or oxygen? A separate idea is to pursue a co-conversion approach where conversion of an industrial waste stream or conversion of a renewable feed (e.g., from biomass) into a valued-added chemical on the anode is performed in parallel with electroreduction of CO2 on the cathode. This presentation will explore some of these aforementioned challenges based on our work as well as the work by others.
Modeling Chemical Microenvironments in Porous Copper Electrodes for CO2 Reduction at Elevated Current Densities
Authors: Bui Justin C , Boehme Annette , Lees Eric W. , Atwater Harry A. , Bell Alexis T. , Weber Adam Z.
Published: September 2023

Electrochemical CO2 reduction (CO2R) presents a promising pathway toward the reuse of CO2 emitted during the production of industrial commodities (e.g., cement, steel, and plastics) to form value-added commodities and fuels at ambient temperatures and pressures with renewably generated electrons. Copper (Cu) catalysts demonstrate the ability to convert CO2 to multicarbon (C2+) products. Additionally, 3-D structured porous Cu electrodes can facilitate the operation of CO2R to C2+ at significantly elevated current densities by enhancing the delivery of CO2 to catalytic active sites on Cu, offering the potential to translate lab-scale understanding to industrial operation. Nonetheless, there still exist selectivity limitations in porous electrode systems due to poor control of the chemical microenvironment, (i.e., the local pH, CO2 activity, and CO intermediate management), in these complex electrodes. Therefore, resolving microenvironment in porous Cu electrodes will be critical to advancing these systems towards industrialization.

In this talk, we explore the use of continuum modeling to resolve and understand the effects of mass transfer and chemical environment in electrochemical CO2 reduction in porous Cu electrodes. We explore two scenarios of porous Cu electrodes performing electrochemical CO2 reduction. The first is the operation of a device employing a bipolar membrane (BPM) in reverse bias, wherein modeling reveals that the proton flux generated by the BPM substantially lowers the pH of the porous electrode and promotes selective CH4 and HCOOH generation. The second is the use of a micro-structured porous electrode that employs an anion-exchange membrane and more selectively generates C2+ products. 2-D modeling reveals heterogeneities in the porous electrode enable hotspots of increased pH that locally enhance C2+ selectivity. Ultimately, this talk underscores the powerful ability of continuum modeling to resolve microenvironments at spatial resolutions beyond what is achievable experimentally, as well as to link changes in microenvironment to changes in local selectivity. These simulations will rationalize and guide the engineering of microenvironment in next-generation porous electrodes for CO2 reduction to C2+ products at industrial scales.
Nanoscale Management of CO Diffusion in CO2 Electroreduction: Boosting Faradaic Efficiency to Multicarbon Products Via Nanostructured Tandem Electrocatalysts
Authors: Wong Andrew Barnabas
Published: September 2023

Tandem catalysis presents a promising strategy to improve the selectivity toward multicarbon products in the electrocatalytic carbon dioxide reduction reaction (CO2RR). For this reaction, it is well-known that CO is a critical intermediate for producing multicarbon products. Thus, control of CO localization and CO diffusion are vital for promoting the formation of multicarbon products. However, the management of CO localization and CO diffusion remains underexplored. Herein, we design a three-dimensional tandem catalyst electrode with silver nanoparticles (Ag NPs) to generate CO as an intermediate product at the bottom of a copper (Cu) nanoneedle array. This design is shown to enhance the conversion of the intermediate product, CO. Via this nanostructured design, CO2 reduces to C2+ products with a high Faradaic efficiency (FEC2+) of 68.4% in a H-cell and 70% in a flow cell with a current density of 350 mA cm-2 are achieved,. These figures-of-merit are currently among the top reports within the known literature for flow cells with partial current density >200 mA cm-2 to C2+ products. More importantly, we employed in-situ Raman spectroscopy and finite-element method calculations to elucidate the origins of the enhanced selectivity. Together, these approaches reveal the crucial role of prolonging the CO diffusion path length in improving CO utilization during CO2 conversion with tandem catalyst systems. The favorable CO2RR selectivity and current density to C2+ products in two distinct environments (H-cell and flow cell reactors) further corroborate that this effect is not limited to a particular reactor environment. Overall, this study provides a valuable strategy for designing tandem catalysts for improved selectivity to C2+ products in CO2RR.
(Invited) Important Factors Affecting Calendar Life of Lithium Metal Batteries
Authors: Cao Xia , Xu Yaobin , Xu Wu , Wang Chongmin , Zhang Ji-Guang
Published: September 2023

With the growing maturity of lithium (Li) ion battery technologies, Li metal battery (LMB) is being revitalized in recent years to achieve high energy density. Great progress has been made in understanding the Li utilization and extending the cycle life of LMBs. However, the study of calendar life of LMBs is still limited, although the calendar life of the battery is also critical for application of LMBs. Therefore, there is an urgent need to investigate the calendar life of LMBs systematically and extend their calendar life. In this work, we will report our recent works on investigation of the calendar life of LMBs based on Li||NMC811 cells using advanced localized high concentration electrolyte, which has already demonstrated excellent cycling stability. Two key criteria, self-discharge rate (percentage of capacity loss per day at open circuit) and recoverable capacity after long-term storage, are used to quantify the calendar aging at different states of charge (SOCs) and temperatures. Together with the postern mortem analysis of Li metal anode and NMC811 cathode retrieved from the long-term stored cells, this work provided an in depth understanding on the important factors affecting calendar aging of LMBs. These findings can guide the storage of LMBs and shed light on the further development of LMBs.

Figure 1
Real-Time, Non-Invasive Magnetic Field Imaging for Diagnosing Current Flow Patterns inside Fault-Simulated Li-Ion Batteries
Authors: Shin Yewon , Lee Mingyu , Lee Hongkyung
Published: September 2023

With the growing popularity of Li-ion batteries in electric-powered mobility, securing battery safety has become a common goal of the battery community. Battery failures are commonly caused by small, undetectable defects that can form during manufacturing and operation, ranging from materials to the cell level. Although the small errors inside the cells trigger catastrophic failures, tracing them and distinguishing cell failure modes without cell anatomy remains challenging. Given that several defects within the cell could cause abnormal current flow compared to the normal cells, visualization of the current inside the battery is informative to find and trace the invisible defects that cannot be detected using imaging tools for the internal structure of fully packaged commercial cells.

This study presents a real-time, non-invasive magnetic field imaging (MFI) method that can signal the magnetic field induced by battery current flow inside the Li-ion pouch cell during cycling (Figure 1). MFI can offer high-speed scanning in a few minutes (~100 mm/min) and spatially high resolution (0.161 mm2) and immediately measure the magnetic field with no need for shielding commonly required for MRI measurement. Based on the Biot-Savart law, we validated magnetic field-current correlation through the MFI of current-carrying 1D straight wires and 2D planes. Then, we found the optimal pouch cell structure for visualizing the current flow patterns using MFI and successfully converted the MFI contour map of the pouch cells into the normalized current distribution. To demonstrate the efficacy of current pattern analysis, we have collected MFI results of fault-simulated batteries (FSBs) to distinguish failure modes that intentionally possess cell manufacturing faults, such as lead-tab contact failure, electrode alignment, and stacking faults. Magnetic field offset using countercurrent-carrying, pouch cell-shaped 2D conductor underneath can selectively detect the failure spots where the current abnormally flows. It is believed that direct visualization of current distribution patterns and figuring out the pattern changes during operation can expedite the non-destructive, immediate diagnosis of commercial cells and troubleshoot safety-related challenges.

Figure 1. Single-layer pouch cells and in operando MFI analysis during charging. (a) Scheme for internal structure of single-layer pouch cell (60 × 90 mm2) with counter-side, center-aligned tabs (CS-C cell). (b) Actual image of CS-C cell and MFI scan and applied current directions during the cell charging. MFI mapping images for (c) Bx
, (d) By
and (e) Bz
vector fields at the cell. White arrows within each MFI contour map indicate the current flow prediction. Applying current density: 5.09 mA cm−2, the cell was situated 6 mm below the sensor (z-distance: 2.5 mm, scanned side: Cathode-side up). The total number of scanned data points are 1699 (11 cm) and 64 (16 cm) in y- and x-directions, respectively.

Figure 1
How Do Impurities in Electrolytes Affect the Electrochemical Performance of Oxides in Lithium-Ion Batteries?
Authors: Khodeir Miriam , Breddemann Ulf , Banov Krum , Novák Petr
Published: September 2023

The recovery and treatment of spent LIBs has already been studied extensively. On one hand, the hydrometallurgical recovery of cathode materials has aroused widespread attention because of its low energy consumption and benefit to the environment. On another hand, the purification of the materials reclaimed from spent batteries is a challenging process with high probability that, later, some remaining impurities such as transition metal carbonates and sulfates could be released into the electrolyte. In this way the impurity content will have a serious impact on the final performance of the battery. To this point different electrochemical and analytical measurements were conducted to elucidate the effects of impurities in the electrolyte formulation, specifically Li, Mn, Co, Ni, and Al carbonates, sulfates, and acetates. The base LP30 electrolyte was intentionally contaminated with a maximum concentration of selected impurity to study the effects of the contaminated electrolyte on the electrode. Different combinations and varieties were explored correspondingly. Test setups were based on both, NMC811 in half cells (vs. Li) and symmetrical Li||Li cells, and the influence of contaminations was thus exploited on the Li counter electrode and on the NMC811 in Li||NMC811 configuration. A number of standard and advanced electrochemical test techniques such as CC-CV, electrochemical impedance, rate capability tests, GITT, and CV was applied for a fully understanding of the electrochemical characteristics of standard cathode active materials such as NMC811 when electrolytes with (artificially downgraded) low purity levels are present. The presentation will focus on discussion of results regarding the presence of transition metals Ni, Co, and Mn as impurities in the electrolyte which showed a significant impact on the electrochemical performance of the tested cells. When the concentration of the impurities increases, both the overpotentials at the cathode and the rate of capacity decay during cycling increase as well. The data shown will be very helpful for the researchers to understand the impact of impurities on the performance of oxide-based LIB cathode materials.
(Invited) Additives Approach to Improve the Performance of LiNi0.5Mn1.5O2 5V Cathodes
Authors: Liao Chen , Wang Bingning , Doan Hieu , Gim Jihyeon , Abraham Daniel P. , Son Seoung-Bum , Trask Stephen E. , Qin Yang , Jansen Andrew N.
Published: September 2023

The high voltage spinel cathode of LiNi0.5Mn1.5O2 has an average working voltage of 4.7 V, high-rate performance with faster diffusion properties, and is viewed as one of the promising cathode materials for high energy lithium-ion batteries. The lack of Co in such cathode materials is also advantageous due to the issues of artisan mining and geopolitical tensions associated with Co mining. However, the high working voltages in LiNi0.5Mn1.5O2 exceeds the stability of electrolyte window and the redox center in the cathode materials is mainly Ni2+ while Mn stays at the 4+ charge state. Due to the dominance of the Mn elements in the cathode, acid leaching from the impurity of the electrolytes can cause Mn dissolution, and the degradation of LNMO//Gr is associated with transition metal dissolution and crosstalk to the anode side, causing loss of inventory Li loss. For example, the decomposition of ethylene carbonate leads to formation of glycolic acid and difluorophosphoric acid (HPO2F2).

Using additives in the electrolyte formulation is an economic way of improving the performance without significant change in either the processing industry or manufacturing technology, and here we present the approach of using a combinatorial approach to optimize the additives for LNMO//Gr full cells. The degradation mechanism will also be discussed. Machine learning (ML) method has been used effectively to predict molecular structures, preferred quantity, as well as formation of interfaces.1-3 In this study, we used ML to formulate the high-performance additives with both improved capacity retention and reduced initial and final impedance.

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3 (7), 7868-7874.

Bhowmik, A.; Castelli, I. E.; Garcia-Lastra, J. M.; Jørgensen, P. B.; Winther, O.; Vegge, T., A perspective on inverse design of battery interphases using multi-scale modelling, experiments and generative deep learning. Energy Storage Materials
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Hildenbrand, F.; Aupperle, F.; Stahl, G.; Figgmeier, E.; Sauer, D. U., Selection of Electrolyte Additive Quantities for Lithium-Ion Batteries Using Bayesian Optimization. Batteries & Supercaps
2022,
5 (7), e202200038.
Temperature-Dependent Electrochemical Impedance Spectroscopy of Li/Li Symmetric Cells and Li/MnO2 Batteries
Authors: Katırcı Gökberk , Ülgüt Burak , Civan Fazlı Eren , Zabara Mohammed
Published: September 2023

Understanding the electrochemical properties of Lithium metal is a crucial step for developing and optimizing rechargeable batteries with lithium metal anodes. During discharge, the lithium metal is oxidized, generating dissolved lithium cations. Transport of the ions to the electrolyte is a significant part of this process. To investigate this process, temperature-dependent EIS experiments are done to independently measure the resistance due to this transport and, eventually, the activation energy.

Electrochemical Impedance Spectroscopy (EIS) is a non-destructive analysis method mainly employed for studying the characteristics of electrochemical energy storage systems. EIS can be invaluable in isolating and studying buried interfaces without physically separating individual components. The anodic process, specifically the charge transfer through the solid-electrolyte interface can be studied without any influence of the rest of the processes.

In this study, we built and measured the Potentiostatic EIS of both symmetric (Li/Li) and batteries (Li/MnO2). Button size (CR 2032) cells were constructed with different battery-grade electrolytes. A symmetric cell can isolate the processes related to metallic lithium. In contrast, a battery type (with an anode and a cathode) can differentiate the effect of the cathode on the anode. A broad range of temperatures (15ᵒC to 65ᵒC) was achieved with a Peltier-powered, homemade climate chamber. The limiting factors were selected according to the freezing and boiling temperatures of the electrolyte systems. Cycling of symmetric cells and discharging of batteries were performed, and the cells were measured after cycling/discharging.

The evaluation of the spectra as a function of temperature and states-of-charge can give a comprehensive understanding of metallic Li and the oxidation process. The resistance modeling the transport as well as the capacitance values were investigated as functions of temperature. The change in resistance values at different temperatures resulted in not only Arrhenius behavior but also regions where Arrhenius behavior is violated.

Interpretation of the temperature dependence provides a detailed understanding of the underlying electrochemical phenomena involving the metallic lithium anode. The effect of electrolytes on Li+ conductance can also be interpreted from the achieved results.
Fast-Charging Electrode Architecture Optimization through R2R Screen Printing
Authors: Wang Ying , Zhu Hongli
Published: September 2023

Creating vertical channels is a viable strategy for reducing the tortuosity and improving the charge transfer kinetics of electrodes, hence enhancing the fast-charge capacity of lithium-ion batteries (LIBs) to actualize fast-charging electrical products. Despite the fact that certain published approaches may directly render channels with electrodes without post-treatment, the control of channels’ diameter and edge distance is a challenge that may be exploited to investigate and optimize the relationship between channels and fast-charging electrodes. Moreover, the intricacy of these methods precludes their industrialization and commercialization. From the perspective of industrial and precision control channels, Roll-to-roll (R2R) screen printing is a simple, cost-effective, industrially scalable, and pattern-customizable continuous additive manufacturing approach for producing vertical channels, reducing the tortuosity of electrodes, and improving their fast-charging capabilities. Low-tortuosity electrodes manufactured by screen printing may be utilized to research the relationship between channel architecture and electrochemical performances of electrodes, as well as to boost and broaden mechanism studies and commercial applications.

In this work, we first applied screen printing to design and fabricate vertical channels with a high resolution. Channel arrangements, diameters, and edge distances were meticulously developed and illustrated for LIB electrodes in order to maximize their capacity at high current rates. Applying LiNi0.6Mn0.2Co0.2O2 cathode ink, clear patterns were printed on the Aluminum substrate. By comparing and filtering, we revealed that 1) the staggered configuration enhances the high-rate charge capabilities of electrodes and 2) the channel diameter and edge distances decreasing improve the rate performances of electrodes. Specifically, at 4 and 6 C, the optimized electrode possesses a charge capacity that is two- and seven-times greater than the conventional bar-coated electrodes, respectively. In addition, neutron computed tomography demonstrated that the Li of the screen-printed electrodes was homogeneously spread along the channels during the charge and discharge operations. We believe that optimized channels accelerate ion transfer in the vertical direction, promote ion diffusion in the horizontal direction, and maximize transfer kinetics for electrodes. Although more research is required to improve the greatest resolution of screen printing technology and refine the internal design of screen-printed electrodes, R2R screen printing technology offers a new opportunity for the optimization, industrialization, and commercialization of fast-charging LIBs.
Voltage Differential Analysis during Power Discharge Operation in Energy Storage Systems
Authors: Wong Clement , Siegel Jason , Stefanopoulou Anna
Published: September 2023

Constant Power Discharge (CPD) is a lucrative operating mode for grid-tied ESS in many energy markets. The CPD mode corresponds to an increasing current drawn as the ESS discharges. The operation can be modeled with an aged anode and cathode open circuit potentials (OCPn/p+RRC) model that can let us identify electrode-level (eSOH) parameters and resistance growth even though we do not have slow discharge with Constant Current. This identification process from realistic ESS field data, namely constant power discharge, will enable continuous eSOH diagnostics and lead to real-time and operando quantification of loss of active material and loss of lithium inventory (LAM and LLI, respectively).

In addition, the timing of when the cell groups' differential voltage peaks occur when the battery system is under constant power operations inform us about the imbalance among cell groups in a module of a battery system, as shown in the figure. Using the time separation among cell differential voltage peaks as a metric of cell imbalance can improve cell balancing algorithms that measure cell imbalance using maximum or minimum voltage, which can be directly affected by the power limits of the battery system.

The efficacy of the proposed algorithms is evaluated for multi-cell modules consisting of NMC/graphite cells, operating as part of a large-scale grid-connected energy storage system. Ultimately, by enabling improved diagnostics of the state of health of individual cells in a battery system and improved cell balancing algorithms, this work will enhance the performance and safety of large-scale lithium-ion battery systems.

Figure 1