bluuebunny/crossref_metadata_2025 huggingface dataset:
Ni/Cu/Ag: An Electrochemically Synthesised Trimetallic Stack for CO2 Reduction
Authors: Dickinson Hannah Louise Alexandra , Symes Mark
Published: September 2023

Climate change, as a result of excess atmospheric CO2 and other greenhouse gases, maintains a position, according to the United Nations as the “defining issue of our time”.1 This has led to research efforts to limit CO2 outputs as well as recycling CO2 which is already present. The electrochemical reduction of CO2 has exponentially gained interest as a possible solution since the late 1990s; if the reduction can be achieved in conjunction with a renewable energy source (e.g solar power), it could be considered carbon negative. Electrochemical CO2 reduction would remove some of the excess CO2 from the atmosphere in conjunction with providing a way for the intermittent energy generated by renewable methods to be stored as chemical bonds, both of which aid the fight against climate change.

Significant focus has been placed on pure metals as electrocatalysts since Hori’s seminal discovery that Cu can uniquely reduce CO2 by more than two electrons to produce hydrocarbons.2 High overpotentials and poor selectivity remain as challenges due to the scaling relations between the simultaneous pathways of CO2 reduction.3 One approach for breaking these is alloying or the use of mixed metal phases. Bimetallic catalysts, particularly those containing Cu have gained considerable interest4, however, limited examples of trimetallic catalysts have been explored.

Herein, a NiCuAg electrocatalyst has been electrochemically synthesised by copper electrodeposition on nickel, followed by galvanic replacement to produce a silver layer. The combination of Ni and Cu was proven to be promising in recent studies5,6 generating desirable non-CO and H2 products such as ethanol. Ag has been shown to promote *CO intermediate production on the Cu surface7 thus its addition to our catalyst should further promote non-CO and H2 products and increase their selectivities.

Linear sweep voltammetry revealed significant activity at potentials more negative than -0.8 V vs. Ag/AgCl, thus CO2 reduction was completed in this region. Reduction products were analysed by gas chromatography and liquid products by NMR. The trimetallic stacks were characterised by XRD, and SEM/EDX before and after reduction to explore their morphology and lifetimes.

References:

[1] https://www.un.org/en/global-issues/climate-change [Accessed 27/11/2022]

[2] Y. Hori, A. Murata and R. Takahashi, J. Chem. Soc., Faraday trans., 1989, 85, 2309—2326

[3] A. A. Peterson and J. K. Nørskov, J. Phys. Chem. Lett., 2012, 3, 251—258

[4] H. L. A. Dickinson and M. D. Symes, Electrochem. Commun., 2022, 135, 107212

[5] X. D. Zhang, K. Liu, J. W. Fu, H. M. Li, H. Pan, J. H. Hu and M. Liu, Front. Phys., 2021, 16, 63500

[6] T. M. Suzuki, T. Ishizaki, S. Kosaka, N. Takahashi, N. Isomura, J. Seki, Y. Matsuoka, K. Oh ishi, A. Oshima, K. Kitazumi, K. Sekizawa and T. Morikawa, ChemComm, 2020, 56, 15008—15011

[7] Y. Zhu, Z. Gao, Z. Zhang, T. Lin, Q. Zhang, H. Liu, L. Gu and W. Hu, Nano Research, 2022, 15, 7861—7867

Figure 1
Electrochemical CO2 Reduction to Ethylene Using Coupled Tandem Electrolyzers
Authors: Strasser Peter
Published: September 2023

The thermal catalytic “Ethylene to Liquids” (ETL) Process is an emerging alternative to the two classical “Fischer-Tropsch” and “Methanol-to-Liquids” process routes toward production of synthetic/e- hydrocarbon fuels. The ETL process, however, relies on a non-fossil ethylene supply. The electrochemical reduction of CO2 to ethylene can serve as an emerging new ethylene supply route.

In this talk, I will highlight some of our recent advances in the design and characterization of efficient CO2 electrolyzers for the electroreduction of CO2 to ethylene in tandem cell designs. The cell tandem consists of a “CO2 to CO” electrolyzer (cell 1) incorporating NiNC single site, coupled to “CO2/CO mixed feed to ethylene” electrolyzer (cell 2). Carbonate transport processes in cell 1 are diagnosed using the carbon cross over coefficient (CCC). Mechanistic aspects of mixed feed reduction are discussed. Performance and its limitations of tandem operation will be discussed.
Electrochemical Reduction of Amine-Captured CO2 in Aqueous Solutions
Authors: Leverick Graham , Gallant Betar M.
Published: September 2023

Technologies that can capture CO2 and enable conversion into value-adding chemicals and fuels or stable minerals for sequestration are vital for transitioning towards net zero or even negative greenhouse gas emissions. Conventional approaches for electrochemically converting CO2 have utilized a decoupled approach of first capturing and concentrating CO2, and then using the concentrated CO2 as a feedstock for conventional electrochemical processes. Direct electrochemical reduction of amine-captured CO2
1,2
can potentially offer advantages by removing the need to thermally regenerate the amine capture solution, which can be energy intensive and typically uses thermal energy from nonrenewable sources. In this talk, we share our recent work on the electrochemical reduction of amine-captured CO2 to value-adding products like CO and stable minerals like carbonates. We discuss the influence of the capture environment on the resulting capture solution chemistry, and how to alter the capture solution speciation through electrolyte design. We further consider the detailed CO2 reduction mechanisms in these amine-containing solutions and provide design strategies for increasing the Faradaic efficiency of CO2 reduction vs. the competitive hydrogen evolution reaction (HER), as well as decreasing the overpotential of CO2 reduction.

References:

(1) Chen, L.; Li, F.; Zhang, Y.; Bentley, C. L.; Horne, M.; Bond, A. M.; Zhang, J. Electrochemical Reduction of Carbon Dioxide in a Monoethanolamine Capture Medium. ChemSusChem
2017, 10 (20), 4109–4118.

(2) Lee, G.; Li, Y. C.; Kim, J.-Y.; Peng, T.; Nam, D.-H.; Sedighian Rasouli, A.; Li, F.; Luo, M.; Ip, A. H.; Joo, Y.-C.; Sargent, E. H. Electrochemical Upgrade of CO2 from Amine Capture Solution. Nat. Energy
2021, 6 (1), 46–53.
Electrochemical Reduction of CO2 in Atmospheric Level Using Bimetallic Catalysts on Liquid-Electrolyte Free Cathodic Half Cell
Authors: Choi Youngyu , Govindan Muthuraman , Kim Daekeun
Published: September 2023

The climate crisis, caused by anthropogenic greenhouse gas (GHG), is one of the most urgent environmental issues. CO2 is one of the GHGs that contributes the most to global warming. Electrochemical CO2 reduction is considered one of the most promising technologies to solve the global warming problem and realize resource recovery. CO2 reduction technology is practically limited because most CO2 reduction techniques are theoretically based on gas-liquid or gas-liquid-solid reactions. Conventional electrochemical CO2 reduction has applied liquid electrolytes, which have the limitation of mass transfer and the problem of liquid product separation. Up to now, most studies have focused on applying high-level CO2 (pure CO2 and % level), which is also practically limited to field application.

This study aimed to establish the gas-solid reaction to enable the electrochemical reduction of CO2 at the atmospheric level (hundreds ppm level). We proposed agar gel solid electrolyte inserted between the bimetallic catalysts and ion exchange membranes system for the gas phase CO2 reduction at liquid electrolyte free state. A bimetallic (Cu-Ni or Cu-Zn) metal-organic frameworks (MOFs) used, as electrocatalyst, after coating on 3D foam base. The electrode surface characteristics were confirmed through x-ray diffraction (XRD) and scanning electron microscope (SEM) analysis, and the presence of bimetals on the electrode was confirmed through energy dispersive X-ray spectrometer (EDS). The redox behaviors of the electrode and it’s catalytic CO2 reaction were confirmed through gas-phase cyclic voltammetry and linear sweep voltammetry. It was observed in the experiment that CO2 removal reached up to 99%, and initial product analysis ended with methane, methanol, and dimethyl ether, which will be analyzed and discussed.

Acknowledgment

This research was supported by Basic Science Research Program through the National Research Foundation of Korea(NRF) funded by the Ministry of Education(NRF-2021R1I1A1A01049901)
Safety Componentry for Mitigating Catastrophic Failure in Lithium-Ion Cylindrical Cells
Authors: Holloway Justin , Balart Murria Maria
Published: September 2023

The lithium-ion cylindrical cell is designed as a thin-walled pressure vessel, with various engineering controls to mitigate catastrophic failure. With an increase in pressure inside the cell, given suitable can wall thickness, the cell will fail through the header componentry. A tear down and inspection method has been developed to observe the header design and componentry of cells. A range of cylindrical cells were investigated - from 18650 to 46950 in size. This involved visual inspection, x-ray tomography, chemical analysis and microscopy. The presence of safety componentry, thickness and material type is discussed; factors which affect the propensity of the cell to fail at this location. Commonly observed was the Current Interrupt Device (CID) vent disc which is designed to mechanically deform in response to pressure increase within the cell. This in turn disconnects the cell circuitry and ruptures, initiating the venting process. Furthermore, cells typically contained a Positive Temperature Coefficient (PTC) device which protects the battery from external short circuits and electrical abuse conditions by limiting current flow when the cell reaches a particular temperature. This approach clearly outlines the safety componentry and their respective functions used within these cell sizes, allowing for a better understanding of battery safety. Additionally, we expect this work to disseminate new developments in larger format lithium-ion batteries as they are being sought for better system performance.
Li2CO3 As the Parasitic Reaction Root for Exacerbated Material Degradation and Performance Deterioration of Ni-Rich Cathode
Authors: Cai Jiyu , Chernova Natasha A. , Prevel Brad , WANG Feng , Chen Zonghai
Published: September 2023

Nickel-rich transition metal oxides is widely regarded as promising cathode materials for high energy density lithium-ion batteries for emerging applications in electric vehicles. However, achieving high energy density in Ni-rich cathodes is generally accompanied with substantial obstacles of lifetime and safety. The major issues of Ni-rich cathodes at high working potentials are originated from the unstable cathode-electrolyte interface, while the underlying mechanism of parasitic reactions to material degradation at the surface of cathode materials is not well understood. In this work, we report the parasitic-reaction-driven structural degradation in LiNi0.83Mn0.1Co0.07O2 cathode by altering interfacial chemistry by synthesizing cathode material in different environments. Our home-build high precision leakage current (HpLC) system verifies that Li2CO3 impurity generated in harsh synthesis environment is a nature root of electrolyte decomposition and parasitic reactions on Ni-rich cathodes. Different rates of parasitic reactions are strongly correlated to drastic discrepancy in electrochemical performance of Ni83 cathodes at different synthesis conditions. The post-mortem characterizations reveal that parasitic reactions promote severe rock-salt phase transformation with more Ni reduction and O deficiency at the surface of cathode materials. This study suggests the significance of developing impurity-free and mitigated parasitic reactions in Ni-rich transition metal oxides for enabling high energy density.

Acknowledgement

Research at the Argonne National Laboratory was supported by the U.S. Department of Energy (DOE), Office of Energy Efficiency and Renewable Energy, Advanced Manufacturing Office. Argonne National Laboratory is operated for the DOE Office of Science by UChicago Argonne, LLC, under Contract DE-AC02-06CH11357.

Figure 1
Understanding Solid Electrolyte Interphase (SEI) Species at the Electrode-Electrolyte Interface in Liquid Lithium Metal Batteries Via in-Situ Fourier Transform Infrared (FTIR) Spectroscopy
Authors: Wang Daniel , Katayama Yu , Minafra Nicolò , Lopez Jeffrey , Shao-Horn Yang
Published: September 2023

Lithium metal is the ideal candidate to replace conventional carbonaceous anodes due to its high theoretical specific capacity of 3860 mAh/g and low negative thermodynamic potential of -3.040 V vs. SHE [1]. Fine tuning the solid-electrolyte interphase (SEI) is critical for the practical implementation of liquid lithium metal batteries [2]. The presence of particular SEI species are hypothesized to improve the coulombic efficiency and mitigate dendrite formation for enhanced lifetime and safety, respectively [2]. Recently, Zhang et al. developed a novel in-situ Fourier transform infrared (FTIR) spectroscopy method to reveal electrolyte oxidation via carbonate dehydrogenation on Ni-based oxides in Li-ion batteries [3]. We leverage this technique and apply it to the Cu side in a Li || Cu battery to probe SEI growth and evolution. In this study, we systematically change the salt, solvent and additive components of the electrolyte and monitor the organic and inorganic SEI species that form under different electrochemical conditions. Furthermore, we directly correlate the chemical composition of the SEI to cell-level coulombic efficiency [4]. Complimentary characterization techniques will be used to further resolve the chemical structure of the SEI. Finally, results from this study will help generate descriptors for the rationale design of new electrolytes.

References

1. Cheng, Xin-Bing, et al. "Toward safe lithium metal anode in rechargeable batteries: a review." Chemical reviews 117.15 (2017): 10403-10473.

2. Peled, E., and S. Menkin. "SEI: past, present and future." Journal of The Electrochemical Society 164.7 (2017): A1703.

3. Zhang, Yirui, et al. "Revealing electrolyte oxidation via carbonate dehydrogenation on Ni-based oxides in Li-ion batteries by in situ Fourier transform infrared spectroscopy." Energy & Environmental Science 13.1 (2020): 183-199.

4. Hobold, Gustavo M., et al. "Moving beyond 99.9% Coulombic efficiency for lithium anodes in liquid electrolytes." Nature Energy 6.10 (2021): 951-960.
Dialing in the Voltage Window: Reconciling Interfacial Degradation and Cycling Performance Decay with Cation-Disordered Rocksalt Cathodes
Authors: Crafton Matthew J , Cai Zijian , Huang Tzu-Yang , Konz Zachary M. , Guo Ning , Tong Wei , Ceder Gerbrand , McCloskey Bryan D.
Published: September 2023

Lithium-excess, cation-disordered rocksalt (DRX) materials have received considerable interest as cathode materials for Li-ion batteries, owing to their high specific capacity and compositional flexibility. Despite these advantages, high interfacial reactivity of DRX materials causes extensive oxidative electrolyte degradation at the cathode-electrolyte interface. In addition to consuming electrolyte, this interfacial degradation is likely to lead to a cascade of deleterious effects throughout the cell, as reactive degradation products drive secondary degradation processes like dissolution of transition metals and decomposition of passivating interfacial species. While in-situ gas evolution measurements conducted by differential electrochemical mass spectrometry (DEMS) allow for the observation and quantification of the degradation processes occurring at the DRX surface, the customized cell configuration with which the technique is conducted is not well suited for capturing the performance decay driven by the interfacial degradation. In particular, a large excess of electrolyte and a large Li metal counter-electrode, both of which are necessary features of DEMS cells, serve to mask the deleterious effects of the interfacial degradation on electrochemical performance. In this work, we reconcile the degradation observed by DEMS with performance decay measured by extended cycling experiments in electrolyte-lean full cells. By comparing DRX outgassing and cycling performance in different voltage windows, we demonstrate a positive correlation between the extent of outgassing and the rate of DRX performance decay during cycling. This result provides a crucial link between the degradation measured by techniques like DEMS and the performance decay measured by cycling experiments, and it allows for the fine-tuning of a cycling voltage window which optimizes the tradeoff between initial performance and long-term stability. Furthermore, this work emphasizes the importance of cell design features, like electrolyte volume and counter-electrode material, and their impact on different electrochemical experiments.
Interphase Design by Localized Super-Concentrated Electrolyte for High-Voltage and High-Power Lithium Metal Batteries
Authors: Ko Youngmin , Baird Michael , Helms Brett
Published: September 2023

Batteries used in electric aircraft must deliver high-power on take-off and landing, providing in stride the ability to recharge at high voltage to make full use of the cathode capacity. Impedance rise associated with electrode–electrolyte interphases remains problematic with conventional electrolytes, resulting in unacceptable power fade. This is exacerbated when recharging cells at high voltage, which is where interphase generation remains poorly controlled. To address these issues, electrolyte design for high-voltage and high-power batteries should emphasize control over the interphase growth contributing to the impedance rise during charge. To this end, we will describe our recent efforts to alter the activity of various electrolyte components at electrode–electrolyte interfaces, granting access to exquisite control over interphase chemistry. Key to our success is the exploitation of ion clustering in locally super-concentrated electrolytes (LSCEs), which produces aggregates with intrinsically different reactivity than solvated species and from which new interphasial chemistries may be produced in-situ. We find in top-performing compositions that interphase stability is most affected by the activity of ethereal solvents in the formulations, particularly at high voltage, and that it is possible to design additives that suppress solvent activity even up to 4.5 V vs. Li/Li+. Li/NMC811 cells cycled with de-novo designed LSCEs maintain 70% of their initial discharge capacity after 1000 cycles with 4 C discharge rate at charge cut-off voltage of 4.35 V, outperforming most reported electrolytes for Li metal batteries. Furthermore, by taking an informatics approach to interphase characterization, we reveal fundamental patterns of reactivity that inform future selection criteria for advanced battery electrolytes.
Eutectic Electrolytes Composed of Li Salt and Sulfones
Authors: Dokko Kaoru , Ugata Yosuke , Ueno Kazuhide , Watanabe Masayoshi
Published: September 2023

Sulfone-based highly concentrated electrolytes are promising electrolytes for high-voltage Li-ion batteries (LIBs), owing to the high thermal and oxidative stabilities of sulfones. In addition, highly concentrated Li salt/sulfone electrolytes exhibit unique Li+ ion hopping/exchange conduction mechanism and high Li+ ion transference number (>0.6).1,2 However, the application of these electrolytes at low temperatures is limited due to the precipitation of a stable crystalline solvate. In this study, the applicability of ternary mixtures of Li salt, sulfolane (SL), and dimethyl sulfone (DMS) as LIB electrolytes was assessed. Due to the increased entropy of mixing, the crystallization of the solvates was suppressed in the ternary electrolytes, resulting in a wide temperature range of liquid sate of the electrolytes.3 In the ternary electrolytes, the network structures of Li+–sulfone–Li+ and Li+–anion–Li+ were formed, and Li+ ion dynamically exchanges sulfones and anions and diffuses more rapidly than these ligands, resulting in a relatively high Li+ transference number. Highly reversible charge–discharge behaviors of the LiCoO2 and graphite electrodes were attained using the ternary electrolyte. Despite the lower ionic conductivity of the sulfone-based electrolyte, the rate capability of the Li/LiCoO2 cell with the ternary electrolyte was comparable to that in a conventional carbonate-based electrolytes.

Acknowledgements

This study was partially supported by the JSPS KAKENHI (Grant No. JP19H05813 and JP22H00340).

References

K. Dokko et. al., J. Phys. Chem. B 2018, 122, 10736.

Y. Ugata et. al., J. Phys. Chem. B 2021, 125, 6600.

Y. Ugata et. al., J. Phys. Chem. C 2022, 126, 10024.
Improved Electrochemical Properties of Aqueous Lithium-Ion Batteries Via the Optimization of Gel Polymer Electrolytes
Authors: Lee Junghun , Yeo Jae-Seong , Yoo Eunji , Yu Hye-Ryeon , Ahn Tae-Young , Kim Jiyoun , Choi Yusong
Published: September 2023

Lithium-ion batteries (LIBs) have been developed for their high energy density and long cycle life in military systems. However, the use of non-aqueous electrolytes based on toxic and flammable organic solvents have raised serious safety concerns including fire and explosion in LIBs. Aqueous LIBs with non-flammable and environmental aqueous electrolytes are promising alternative to eliminate the safety issues. Because aqueous batteries use water as a solvent of electrolyte, they are stable with no flammable. However, the narrow electrochemical stability window (ESW) of water in aqueous electrolytes limits operating voltage and energy density of aqueous batteries. Recently, ESW was expanded by applying a high concentration lithium salt electrolyte called “water-in-bisalt” (WIBS). A 4.0 V aqueous LIB was developed by passivating graphite anodes with hydrophobic LiTFSI-HFE gels, which effectively extended electrolyte stability [1].

In this study, we developed a 4.0 V aqueous LIBs using UV-cured gel polymer electrolytes. Highly concentrated UV-cured gel polymer electrolytes were coated to cathodes and UV-cured gel protection layers were applied to anode surfaces for improving stability. Also, gel polymer electrolytes were optimized with various lithium salts and additives. We also evaluated cycle performance and safety such as cutting, penetration test with LiMn2O4∥graphite pouch type cells. There were no fires and explosions.

References

[1] Yang et al., Joule 1, 122-132, September 6, 2017
Improved Sigr/NCM523 Cycling Via Triethyl Phosphate-Solubilized Lithium Nitrate Electrolyte
Authors: Rynearson Leah , Jayawardana Chamithri , Rodrigo Nuwanthi Dilhari , Lucht Brett L.
Published: September 2023

The performance of silicon-graphite (SiGr)/Li and SiGr/NCM523 cells were investigated in electrolytes containing lithium difluoro(oxalate)borate (LiDFOB) and lithium nitrate (LiNO3) in ethylene carbonate (EC), ethylmethyl carbonate (EMC), and different proportions of triethyl phosphate (TEP). While the LiDFOB and LiNO3-containing electrolytes both showed improved cycling stability over industry standards, the 10% TEP electrolyte demonstrated the best capacity retention in half cells and the best overall cycling performance in full cells. Ex-situ surface analysis reveals that the LiDFOB and LiNO3 preferentially decompose on both the anode and cathode surface during the first cycle to generate films consisting of oxalates, fluoroborates, and nitrate reduction products. Therefore, incorporation of two different film-forming electrolyte additives into the electrolyte is significantly more beneficial in formation of a robust SEI and improved cycle life in silicon-containing anodes.
In-Situ Investigation of the Cathode Electrolyte Interphase Formation, Kinetics, and Composition
Authors: Paden Olivia , Sa Niya
Published: September 2023

Solid electrolyte interphase studies are the next avenue for improving the performance of rechargeable lithium-ion batteries. The cathode electrolyte interphase (CEI) plays a critical role in stabilizing lithium composite cathodes which are known to suffer parasitic side reactions that lead to rapid capacity fade, cathode degradation, and thermal runaway. However, the CEI is under-reported compared to the solid electrolyte interphase on the anode because of its complex surface chemistry, nanoscale structure, and the high potential that next-generation cathodes undergo during cycling. There is ambiguity in the relationship between cathode properties and the formation, kinetics, and performance of CEI, which, if resolved, could lead to a further understanding of the conditions that produce a stable CEI and provide guidance for engineering more effective CEI. In this work, lithium manganese oxides were used as a case study to investigate the CEI’s in-situ behavior in terms of formation, kinetics, and composition.
Establishing an Appropriate Voltage Window for Stable Cycling of Li/Mn-Rich Layered Oxide || Graphite Full Cells
Authors: Arifiadi Anindityo , Schmuch Richard , Kasnatscheew Johannes , Winter Martin
Published: September 2023

Li/Mn-rich layered oxide cathode active materials (LMR) have gained attention due to their exceptionally high practical specific discharge capacity (>250 mAh g-1) originating from both conventional cationic as well as anionic oxygen redox contributions. To achieve this high capacity, the Li2MnO3-like regions of the material, which give rise to oxygen redox need to be electrochemically activated at high voltage (above 4.6 V versus Li+/Li0). This high voltage activation, however, results in the destabilization of lattice oxygen that creates subsequent adverse phenomena such as first-cycle hysteresis and the evolution of redox couples. The latter happens continuously during cycling and results in the activation of Mn3+/Mn4+ redox couple. This redox couple involving Mn3+ is problematic because, at this oxidation state, Mn disproportionation reaction can occur, resulting in the formation of highly soluble Mn2+ species. In a half-cell setup, the impact of Mn dissolution may be subtle, however, in LMR||Graphite full cells, the impact is consequential.

This work focuses on investigating the degradation mechanism of LMR||Graphite full cells at different voltage windows applied during the activation cycles and the long-term cycling. These different voltage windows alter the redox contributions and thus affect the long-term performance of the cells. We observe that lowering the upper cut-off voltage (UCV) from 4.7 V to 4.5 V during the entire cycling process can increase capacity retention, although rapid degradation can still be observed. Only when the UCV during the long-term cycling is lowered to 4.3 V, can we obtain incremental degradation of the cells. We also show that lowering the activation cycles UCV to 4.5 V is beneficial for long-term cycling due to the lower contribution of Mn3+/Mn4+ redox couple after the activation cycles. Finally, we observe that increasing the lower cut-off voltage from 1.9 V to 2.4 V results in higher discharge voltage. Nevertheless it is followed by a reduction in discharge capacity, resulting in a lower specific energy. This study offers insights into the high-voltage cycling performance of practical LMR||Gr full cells that can be used for the foundation of material design to alleviate the adverse effect of oxygen redox in LMR.
Estimation of Crack Formation By Digital-Twin Structure of a Single Secondary Particle
Authors: Song Jihun , Lee Hyobin , Kim Suhwan , Lim Jaejin , Kim Kyung-Geun , Lee Yong Min
Published: September 2023

Most of the recently commercialized active materials for lithium-ion batteries (LiB) adopt secondary particles, and most of them are designed by evaluating cell-level electrochemical properties. Therefore, the relationship between particle design and battery performance is not properly understood because it is not possible to grasp the intrinsic properties of the electrode active material. Therefore, a single particle measurement technique has been developed in which a gold or platinum filament having a diameter of several tens of microns is directly contacted with a single particle to evaluate the single particle electrochemical properties. However, since it is a non-sealed battery system, only less-volatile electrolytes can be applied. Also, the experiment is difficult because the contact between particle and filament can easily break down with small vibration. Additionally, there are a lot of particle design parameters such as particle shape, size, and size distribution. Moreover, with operating conditions, the particle design needs to be changed. So, it is challenging to cover all cases by experiment.

In this study, digital-twin structure of a single secondary particle was formed using focused ion beam / scanning electron microscope. Using the digital-twin structure, digital-twin electrochemo-mechanical model was developed and more than 99% of accuracy was secured by comparing the voltage profiles with result of single particle measurement technique. Using the well-matched model. Operando analysis of electrochemical properties (State of Lithiation, overpotential, potential, and concentration) and mechanical properties (von Mises stress and strain energy density) were performed. The strain energy density can be the criteria to determine the crack formation by comparing with the fracture toughness which is the strain energy density when the fracture occurs.
Dilation Study of Si-Rich Anode in the Next Generation Lithium-Ion Batteries
Authors: Banifarsi Sanaz , Abdellatif Abdelaziz , Wohlfahrt-Mehrens Margret
Published: September 2023

Silicon has attracted a lot of attention as anode material in lithium ion batteries due to its high practical capacity (around 3579 mAh.g-1 at Li15Si4 phase [1]). The main drawback for the use of Silicon is its significant volume expansion around 300% in fully intercalate state which causes particles pulverisation, dynamic formation of the solid electrolyte interface (SEI), losing electrical contact and capacity loss.[2] The solution is hidden in using silicon composite instead of pure silicon, [1,3] applying partial lithiation or delithiation process,[4] and improving the electrical particles contact by applying optimum external pressure.[5] The main aim of the current study is to investigate the electrochemical performance and the dilatometry behaviour of a multilayer pouch cells (0.06 to 1.5 Ah) under the external mechanical pressure. Using 1/3 of the Si capacity in order to stabilized electrochemical performance of a highly content silicon anodes (70 wt% Si), exhibited electrode irreversible expansion around 20% after 3 cycles of formation at 0.1C and 75% electrode thickening after 200 cycles at 0.5C.

References

[1] P. Li, H. Kim, S.-T. Myung, Y.-K. Sun, Energy Stor. Mater. 35 (2021) 550–576. https://doi.org/10.1016/j.ensm.2020.11.028.

[2] L.Y. Beaulieu, K.W. Eberman, R.L. Turner, L.J. Krause, J.R. Dahn, Electrochem. Solid-State Lett. 4 (2001) A137. https://doi.org/10.1149/1.1388178.

[3] P. Kargl, V. Drews, P. Daubinger, O. Schweighofer, M. Marinaro, G.A. Giffin, M. Wohlfahrt-Mehrens, A. Thaler, J. Power Sources 548 (2022) 232042. https://doi.org/10.1016/j.jpowsour.2022.232042.

[4] M.N. Obrovac, L.J. Krause, J. Electrochem. Soc. 154 (2007) A103. https://doi.org/10.1149/1.2402112.

[5] M. Göttlinger, P. Daubinger, W. Stracke, S. Hartmann, G.A. Giffin, Electrochim. Acta 419 (2022) 140354. https://doi.org/10.1016/j.electacta.2022.140354.

Acknowledgment

Funding of the project HysKaDi (03XP0321) by the German Federal Ministry of Education and Research (BMBF) are gratefully acknowledged.

Figure 1
Study of Transport Phenomena in Next Generation Lithium Batteries, Assisted by 3D Printing
Authors: Laventure Audrey , Dolle Mickael , Faral Manon
Published: September 2023

Lithium-ion batteries (LIB) have a major role in the global energy future as they currently offer the best alternative for energy storage. The increase in energy demand is driving the development and optimization of high-performance batteries. With the specific objective of improving energy densities, studying the limiting phenomena such as the transport of species through the batteries’ components is essential. In this regard, using a new emerging technology such as 3D printing to process some of the batteries’ components could answer some issues. Thanks to its design flexibility compared to conventional manufacturing methods, this technique offers the possibility of creating customizable and complex architectures that could help unravel limiting phenomenon.

More specifically, 3D printing is an interesting way to design solid electrolytes. This study aims at showing how the structure, the composition and the configuration of the solid electrolyte will affect the systems properties and thus its electrochemical performances. A first part of the study consists in evaluating the feasibility of 3D printing a solid composite electrolyte with a complex architecture. Thus, 3D printing techniques will be discussed as well as the formulation of a ceramic ink. Other aspects will be addressed such as the ink printability studies via rheology, the processing of different structures via printing and the print fidelity. Using different compositions and architectures, different structural characterizations and conductivity tests are performed to evaluate the impact of the processing on the system properties. The optimization of this proof of concept involving various polymer/ceramic ratios, geometrical architectures and processing studies is an interdisciplinary project that can lead to significant advances in the field of batteries.
Comprehensive Approach about Time-Relevant Degradation of Ni-Rich Cathode Materials for Electric Vehicles
Authors: Park Nam-Yung , Kim Su-Bin , Lee Han Uk , Sun Yang-Kook
Published: September 2023

With the prevalence of electric vehicles, Ni-rich layered cathodes have been extensively developed to increase the energy density of Li-ion batteries (LIBs). However, cathodes with a high Ni content suffer from inherent structural and chemical instabilities, which lead to rapid capacity fading and thermal instability.1 In particular, the rapid capacity fading of Ni-rich layered cathodes is largely caused by microcracking and the resultant microstructural instability.2 In addition to microcracking, the time during which highly reactive Ni4+ ions are exposed to the electrolyte when the cathode is in a highly charged state also affects the deterioration of the cathode. Although the exposure time is not significant for cathodes with Ni contents of <60%, the calendar aging test of Ni-rich cathodes reveals that the exposure time, especially at high SoCs, critically affects the degradation of these high-Ni cathodes, as the internal surfaces of the particles are also exposed to the electrolyte via the microcracks.3 The exposure time is particularly pertinent for electric vehicle (EV) LIBs, as they remain stationary for long periods in the highly charged state and are operated intermittently. Consequently, the upper SoC limit of EV LIBs is commonly limited to ≈85%, but this limits the driving range and increases the cost of the batteries. Therefore, a holistic approach considering real-use behavior, as well as the properties of the material itself, is needed to overcome the limitations of Ni-rich cathodes.

Here, 1 mol% B doping of a core–shell concentration gradient (CSG) Li[Ni0.88Co0.10Al0.02]O2 cathode (CSG-NCA88) is shown to dramatically alter the microstructure of the cathode and effectively protect the particle interior from parasitic electrolyte attack. The B-doped CSG-NCA88 cathode, CSG-NCAB87, maintains its original microstructure even after holding for 500 h in the fully charged state, whereas irreversible structural damage occurs in the pristine CSG-NCA88 cathode during the prolonged electrolyte exposure. The long-term cycling results confirm that the capacity retention of the cathodes is determined by the electrolyte exposure time at a high SoC and that microstructural modification can effectively suppress the time-dependent degradation from electrolyte attack. The proposed CSG-NCAB87 cathode can be utilized at full capacity without restricting the SoC, thus realizing the development of economical high-energy-density LIBs.

Reference
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[2] H.-H. Ryu, K.-J. Park, C. S. Yoon, Y.-K. Sun, Chem. Mater. 2018, 30, 1155.

[3] H.-H. Ryu, G.-T. Park, C. S. Yoon, Y.-K. Sun, Small, 2018, 14, 1803179.
Experimental and Computational Study on SEI Composition and Electrochemical Performance of Lithium-Ion Battery with Silicon Oxide-Graphite Composite Electrode
Authors: Nakamoto Mitsunori , Inoue Nobuhiro , Kumita Hideyuki
Published: September 2023

Demand on batteries with high energy density is surging. Conventionally, carbon materials have been used as an anode active material, but recently silicon materials are likely to be incorporated to form a composite anode in lithium-ion batteries (LIBs) for higher energy density. However, LIBs which include silicon materials in anode tend to show a low cycle performance especially the ratio of silicon materials in the anode increases. Commercial LIBs still have difficulty in incorporating large amount of silicon materials especially under the requirements where multiple aspects like safety, charging rate and energy density should be totally met.

One potential pathway to improve the cycle performance in LIBs with silicon materials is to tune the nature of solid electrolyte interphase (SEI), a thin film which forms at the interface between anode active material and electrolyte. The nature of SEI is particularly important for LIBs with silicon materials because such silicon active materials show large volume changes during battery operation and SEI is dynamically reconstructed. It has been qualitatively reported so far that LiF is an important component for better battery performance. Our work suggests that the ratio of LiF in initially formed SEI is a crucial factor to realize improved cycle performance in such LIBs.

In our work, anode with silicon oxide (SiOx)-graphite composite is considered. We investigated the relationship between electrochemical performance of the cell with such composite electrode and the nature of the film estimated by characterization and molecular simulation. We systematically changed the composition of liquid electrolyte to form various types of SEI on anode surface. For characterization, both fresh and aged cells with different electrolytes were dismantled, and SEI components were extracted by designated solvents, then NMR (nuclear magnetic resonance) was applied to identify the SEI species and quantify the amounts of major SEI components. Comparison between the evolution of SEI amount and an impedance element in electrochemical impedance spectroscopy during aging indicates that degradation of the cells is closely related to the growth of SEI. To further deepen understanding the role of LiF, molecular dynamics simulation was carried out, where the mixture of LiF and typical organic SEI was modelled. Correlation between calculated mechanical property and measured electrochemical performance of the cells were revealed. In our presentation, the requirements that SEI should satisfy will be discussed from the insight of electrochemical measurements, NMR characterization and modeling approaches.
Modeling the Anisotropic Transport Behavior for Axisymmetric 2D Electrode Particles Using a Modified Pseudo-2D Model Framework
Authors: Hoffman Robert M. , Evans Tyler A. P. , Taghikhani Kasra , Berger John R. , Kee Robert J.
Published: September 2023

This presentation extends widely used pseudo-2D (P2D) Li-ion battery models to include electrode particles that have strong crystal-scale anisotropies and possibly non-spherical shapes. Typical P2D models predict Li transport with representative spherical electrode particles by solving a one-dimensional diffusion equation in spherical coordinates. However, battery electrodes (graphite, NMC, etc.) may have strong crystalline anisotropies, leading to transport and mechanical properties that vary by orders of magnitude depending on crystallographic orientations. The anisotropic transport can cause large concentration gradients, possibly leading to particle fracture associated with concentration-induced stress. The remainder of the P2D model, such as Li-ion transport within the electrolyte solvent, remains essentially unchanged. The charge-transfer boundary conditions at the particle surfaces do need to accommodate the crystallographic anisotropy.

The present model discretizes representative electrode particles in a two-dimensional finite-volume axisymmetric geometry, accounting for the anisotropic behaviors. The computational burden is greater than it is for the one-dimensional spherical solution. However, the P2D model with two-dimensional axisymmetric particle discretization still runs in only a few minutes on a typical personal computer.

The model shows how electrode-particle anisotropy affects the battery performance, such as charge-discharge characteristics and electrochemical impedance spectroscopy. The model also predicts the concentration gradients and correlated stress for various axisymmetric, non-spherical particles.
Low Temperature Research and Improvement on Lithium Ion Batteries
Authors: Fu Yanbao , Collins-Wildman Daniel , Higa Kenneth , Battaglia Vincent
Published: September 2023

Lithium ion batteries have been the dominant power sources in portable electronics and electric vehicles due to their high energy density, long lifetime and environmental benignity. However, it is a big challenge for lithium ion batteries to be used at low temperature. Compared with the performance at room temperature, lithium ion batteries deliver much less capacity and energy at low temperature. The poor low temperature performance restricts the usage of lithium ion batteries for power electronics and electric vehicles in the winter. The results of previous research, suggest that the poor low temperature performance is attributed to the freezing of the liquid electrolyte which leads to low ionic conductivity and high interfacial resistance, especially on the anode side. Other researchers tried using a solvent with low melting point to partially replace ethylene carbonate or adding some additives to the electrolyte to enhance the ionic conductivity or modify the interface to reduce the resistance and then deliver more capacity and energy.

In this research, we investigated the discharge capacity, energy, pulse power and electrochemical impedance spectroscopy at different depths of discharge of NCM622/Graphite lithium ion batteries at varied temperatures. We found that the discharge energy and pulse power are sensitive to the temperature decreasing. For the NCN622/Graphite cell (2.5 mAh cm-2) with commonly used LiPF6-EC/EMC electrolyte, at -20 oC the cell is able to deliver 65% capacity of that at 30 oC with C/3 discharge current rate, while the delivered energy is only 60%. The 30 seconds pulse power became much worse at -20 oC compared with the power at room temperature. In our research the poor low temperature performance is not from the low ionic conductivity and interfacial resistance. The dominant factor is the charge transfer impedance from the cathode side of the cell.

To improve the low temperature performance, we explored the addition inexpensive nano-particles as the additive into the electrolyte. The cell composed of this electrolyte is able to release more than 70% capacity and energy at -20 oC of that measured at 30 oC. The charge transfer resistance in the fully charge state decreased almost 80% compared to a cell with baseline electrolyte. Meanwhile, the additive has no effect on the long-term cycling (1000 cycles) and stability at high temperature (55 oC)

Fig.1. Normalized capacity and energy. Fig.2. The EIS of the full cell at 30 oC and -20 oC.

Figure 1
Understanding the Energetics of Ion Intercalation in Lithium-Ion Batteries
Authors: Aggarwal Abhishek , Gordiz Kiarash , Zguns Pjots , Vivona Daniele , Baskin Artem , Grossman Jeffrey , Lawson John , Shao-Horn Yang
Published: September 2023

Researchers around the world are working to increase the energy efficiency and the energy density of lithium-ion batteries. However, the mechanism and the factors influencing the charge transfer (CT) kinetics at the electrode-electrolyte interface remain poorly understood. Recently, Fraggedakis et al. [1] proposed the theory of coupled ion-electron transfer (CIET) to explain the process of charge transfer at the electrode-electrolyte interfaces. In this work, we provide deep atomistic understanding of the interfacial CT mechanism, the underlying microscopic steps, and the factors influencing the CT rates in a Li-ion battery. In addition, we connect our computational results with the experimental measurements and Marcus-like theories of charge transfer (viz. CIET [1]).

Using state-of-the-art computational techniques, such as metadynamics and molecular dynamics simulations, we model the electrode-electrolyte interface and compute the free energy profiles of Li-ion adsorption at the interface, subsequent ion-desolvation, and intercalation into the cathode. Specifically, we study the adsorption of Li+ ion on LixCoO2 surface for different (i) electrolytes, (ii) Li+ concentrations in electrolyte, (iii) salt compositions, and (iv) temperatures to uncover the trends governing charge transfer kinetics. Using the obtained free energy profiles of Li+ desolvation and intercalation at the solid-liquid interface, we provide estimation of the adsorption and desolvation energy at the interface and identify the key energy barrier which acts as the roadblock for ion transfer in Li-ion batteries. Based on this identified key kinetic barrier, we then propose strategies to tune the energy barrier for ion transport. In addition, we identify important thermo-physical observations that can explain the existing experimental trends. For instance, we find that increasing the salt concentration in the electrolyte increases the accessible solvation states to Li+ ion, thereby changing the energy barrier for the Li+ ion to intercalate into the electrode, and thus leading to higher currents. Moreover, we find that changing the salt from LiPF6 to LiClO4 further modifies the energy landscape of Li+ ion, leading to increased measured experimental kinetics as well. This work builds an understanding of the influence of various effects, such as salt concentration and electrolyte composition, on the Li+ transport properties at interfacial regions. Our computational framework can also provide descriptors to enhance the performance and stability of lithium-ion batteries.

References:

Fraggedakis, D., McEldrew, M., Smith, R.B., Krishnan, Y., Zhang, Y., Bai, P., Chueh, W.C., Shao-Horn, Y. and Bazant, M.Z., 2021. Theory of coupled ion-electron transfer kinetics. Electrochimica Acta, 367, p.137432.
(Invited) Novel Reduced-Order Electrochemical Models for Battery Simulation
Authors: Gao Tianhan , Lu Wei
Published: September 2023

It is important to accelerate the calculation efficiency while guaranteeing the accuracy for battery simulations. We introduced novel reduced-order physical-based models for simplifying the P2D electrochemical model, where the lithium-ion concentration and electrolyte potential distribution are represented by polynomial equations. Two types of reduced-order models, including the revised single-particle model (RSPM) and the fast-calculating P2D model (FCP2D) are developed based on the simplification method of lithium diffusion modeling within particles. Results show that the proposed RSPM and FCP2D reduced-order model can represent the battery parameters, including terminal voltage, overpotential, interfacial current density, lithium-ion concentration distribution, and electrolyte potential distribution, accurately and efficiently. Specifically, the RSPM owns a better performance (embodied in a satisfactory accuracy and a higher efficiency) under lower C rates operation, while the FCP2D can guarantee a higher accuracy than the RSPM under higher C rates operation. This work provides a novel approach for promoting battery simulation efficiency through physical-based models, which contributes to the acceleration of the responding speed of battery management systems and the battery development period.