bluuebunny/crossref_metadata_2025 huggingface dataset:
High-Speed AFM Observation of Electrolytic Nanobubbles Formation on HOPG
Authors: Ohashi Ryuto , Matsushima Hisayoshi , Ueda Mikito
Published: February 2024

Introduction

Nanobubbles (NBs) on solid surfaces are an interesting topic for surface and colloid science. Since the diameter of NBs is less than 1 μm, NBs can be morphologically measured by atomic force microscope (AFM) [1]. However, due to the slow scanning speed of conventional atomic force microscope (AFM), the nucleation and growth process is not yet known. We previously applied high-speed AFM (HS-AFM) for NBs’ evolution during water electrolysis [2]. Here, we discuss the NBs’ formation during cyclic voltammetry (CV).

Experimental

The experimental cell was a three-electrode system at room temperature. The working electrode was highly ordered pyrolytic graphite (HOPG). The counter and reference electrodes were Pt wires. The electrolyte was a sulfuric acid solution (5 mmol L-1). CV was performed by a potentiostat. HS-AFM was operated in dynamic mode. The scanning speed was 0.5 frame s-1 and the size was 1 × 0.75 µm2.

Results and discussion

When the potential was swept to the anode from the open circuit potential, the pancake-like NBs were formed (Fig. 1). The height was ~5 nm, and the surface roughness was very small (< 1 nm). The pancake NBs grew along the step side and moved actively on the surface. They occasionally coalesced with neighboring NBs.

On the other hand, when the potential was swept to the cathode, the dynamic process was the opposite. The pancake NBs dissolved. This poster will present the dynamic variation of electrolytic NBs during the CV.

Reference

[1] X.H. Zhang et al., Langmuir, 23, 1778 (2007).

[2] M Mita, H Matsushima, M Ueda, H Ito, J. Colloid Interface Sci., 641, 389 (2022).

Figure 1
Enhanced Synergistic Effect by Facile Tuning of Nickel Doping on Cobalt Phosphide as Electrochemical Catalysts for Hydrogen Evolution Reaction in Alkaline Water Electrolysis
Authors: Sim Jun Seok , KIM Wan Sik , Tamboli Asiya Mohaseen , KIM Bong Hyun , Jung Young Han , Kim Chang Hee
Published: February 2024

The development of efficient and cost-effective electrocatalyst for the hydrogen evolution reaction (HER) is essential for alkaline water electrolysis. Cobalt phosphide (Co2P) is a promising non-noble electrocatalyst material for HER due to its low cost and high stability in alkaline solutions. However, improving the HER performance of Co2P is still challenging due to its catalytic mechanism in which Volmer reaction is the dominated rate-determining step. In this study, we introduced nickel to cobalt phosphide in order to improve its performance as an electrocatalyst because nickel is known to be beneficial for water dissociation (Volmer reaction), while cobalt is beneficial for producing gaseous hydrogen (Heyrovsky or Tafel reaction). This synergistic effect between nickel and cobalt phosphide contributes to enhancing HER performance. Also, it is crucial to find the optimal ratio of nickel and cobalt for maximizing synergistic effect. To facilitate the optimization process, a co-sputtering system was used to fabricate the electrodes. The resulting Ni-doped Co2P showed significantly enhanced HER performance with low overpotential of ~91 mV at 10 mA/cm2 and Tafel slope of ~47 mV/dec compared to pristine Co2P in electrochemical analysis. This enhancement is attributed from the optimized ratio between the sites where water dissociation and adsorbed hydrogen recombination reactions occur. The findings of this study demonstrate that the nickel cobalt phosphide electrode is a promising electrocatalyst for HER in alkaline water electrolysis.
Hydrogenation, without H2(g)
Authors: Sperryn Jessica F. , Berlinguette Curtis P.
Published: February 2024

Industrial hydrogenation requires high temperatures and high pressures of H2(g), which is sourced from fossil fuels. Membrane reactors enable hydrogenation reactions to occur at ambient conditions by sourcing hydrogen from water instead of H2(g). The reactor operates by separating the electrochemical generation of protons in water from the hydrogenation of unsaturated chemicals in the adjacent hydrogenation compartment. These two compartments are separated by a palladium foil that acts as a cathode, a membrane, and a catalyst. This presentation will summarize our work demonstrating a wide range of substrates that can be hydrogenated upon control of the use of different solvents, electrolytes, current densities, and catalysts. I will highlight the potential to hydrogenate substrates in our reactor that are of consequence to a future renewable energy infrastructure.

Figure 1
Dark-Field Microscopy of Au@Ag Core Shell Nanoparticles during Electrochemical Conversion Reactions
Authors: Braemer Lars Fabian , Wonner Kevin , Tschulik Kristina
Published: February 2024

Nanoparticles (NPs), which can nowadays be synthesized in various shapes and compositions, provide special physical properties that can strongly differ from their respective macroscopic counterparts. In particular due to the highly increased surface-to-volume ratios, NPs are frequently used as catalyst material.(1) Furthermore, metal NPs exhibit adjustable spectral properties arising from the interaction of the conduction band electrons with electromagnetic radiation, called localized surface plasmon resonance (LSPR).(2) The NPs appear colorful, where spectra of single NPs contain fundamental information about the size, shape and composition of the NP. Using Dark-Field Microscopy (DFM), the LSPR spectra of individual NPs can be precisely detected by hyperspectral imaging and CCD imaging. Combining this method with electrochemistry allows the monitoring of electrochemical processes on a single NP level.(3) In our work we focus on Au@Ag Core Shell NPs which are a promising candidate for catalytic applications. The LSPR spectra of the core shell NPs were herein tracked during the electrochemically induced dissolution of the Ag shell in nitrate solution exhibiting a “naked” Au core with possibly increased catalytic activities. With this spectro-electrochemical approach, an intensity decrease accompanied by a spectral red-shift was found during the dissolution of the Ag, which correlated with the simultaneously obtained current responses.

Figure 1: Left: DFM CCD images of core shell NPs before and after linear sweep voltammetry (LSV) are displayed (-0.2 to 0.6 V vs Pt, 5 mV/s), center: LSPR intensity gradient of > 600 core shell NPs which were individually tracked during the LSV (black) including the current response (red), right: LSPR spectra of a representative core shell NP before and after the LSV.

References

(1) Ealia S. A. M.; Saravanakumar M. P. IOP Conf. Ser.: Mater. Sci. Eng.
2017, 263, 032019.

(2) Sambur J. B.; Chen P. Annu Rev Phys Chem
65, 395–422.

(3) K. Wonner et al. J. Am.
Chem. Soc.
2018, 140, 12658–12661.

Figure 1
Nanoscale Photoelectrochemical Mapping of Two-Dimensional Electrodes
Authors: Kholimatussadiah Septia , Qorbani Mohammad , Chen Kuei-Hsien , Chen Li-Chyong
Published: February 2024

Electron transfer plays a significant role in many chemical processes, especially in the catalytic reactions involved in photoelectrochemical energy conversion and storage. Revealing the electron transfer behavior at the interface of electrode-electrolyte is thus of great importance. Here we fabricate atomically thin semiconductor MX2 (M = Mo, W; X = S, Se) by chemical vapor deposition method and directly map the photoelectrochemical behavior using Atomic Force Microscopy-combined with light-induced Scanning Electrochemical Microscopy (AFM-SECM). AFM-SECM feedback mapping shows a layer-dependent photoelectrocatalytic ability of MX2 to oxidize the redox species Ru2+ back to Ru3+. Moreover, AFM-SECM generation and collection mode shows the potential-dependent edge and basal plane activity for the hydrogen evolution reaction of WSe2. Compared with monolayer and bilayer, few-layer WSe2 shows better stability in an electrochemical environment, faster electron transfer, and higher hydrogen production. Furthermore, finite element method based numerical simulations using MATLAB® and COMSOL Multiphysics® is performed to calculate the electron transfer rate constants k0 and simulate the steady-state concentration gradient. Finally, the photoelectrochemistry at MX2 electrode-electrolyte interfaces are spatially resolved and understanding this behavior will be useful for the future photoelectrochemical devices.
Electrolyte Flow through Porous Carbon Electrodes Under Compression in the Hydrogen-Bromine Redox Flow Battery
Authors: Ochoa Fajardo David
Published: February 2024

The conditions of electrolyte flow affect the performance of redox flow batteries through the combined effect of pumping energy and electrode overpotential. In the hybrid hydrogen-bromine flow battery the conditions of electrolyte flow depend on the trans-membrane pressure exerted by hydrogen gas in the membrane electrode assembly, which has a compressive effect on the liquid side electrode.

This study aims at characterizing the effect of hydrogen pressure on flow characteristics and investigate its effect on transport behavior. We selected two types of porous carbon electrodes, carbon paper and carbon cloth, with and without surface conditioning, and study liquid flow at the compression ratios expected in a hydrogen-bromine cell under increasing operation pressure.

Combination of electrode characterization with electrolyte velocity measurements obtained by particle image velocimetry in flow-through configuration allow characterization of liquid flow through porous electrodes, and attempt to relate it to electrode morphology. Electrochemical testing is then is used to reveal the effect of electrode compression on electrochemical active surface area, estimated by the capacitance of the double layer, and cell polarization.

The velocity field is revealed to be highly dependent on the fiber structure of the electrode and surface conditioning. The effect of compression manifests early and impacts the uniformity of flow through the porous structure. Additionally, the changes in active area and cell resistance result in a complex combination of factors that determine cell polarization.

Figure 1
Electrochemical Peroxide Generation for in Situ Disinfection
Authors: Vijapur Santosh Hanamant , Hall Timothy , Taylor E. Jennings , Wang Dan , More Santosh R , Liu Danny , Snyder Stephen
Published: February 2024

Among the numerous technological advances sought in order to facilitate human exploration and habitation outside of earth’s atmosphere, solutions and innovations are needed for processing resources locally to support sustainable and long duration space missions. Such in-situ resource utilization (ISRU) is aimed at reducing the payload mass during launch and eliminate the need for ground support for long-term missions and ultimately space colonization. Disinfection needs is an area of particular need, which is currently accomplished through the use of pre-packaged, disposable, wetted disinfection wipes. These items represent an appreciable carry-along mass and disposal/replacement burden requiring ground support. Therefore, a system is desired that could utilize onboard utilities to create disinfecting solutions to eliminate storage/disposable problems of the wetted wipes and further reduce the astronaut’s dependence on earth-based supplies.

Faraday Technology Inc. is addressing this challenge by demonstrating an in-situ approach, which utilizes on-board supplies of air and water for on demand electrochemical generation of hydrogen peroxide. Hydrogen peroxide is well-established disinfectant with non-toxic decomposition products (viz., O2 and H2O), that is safe enough for human contact to be sold commercially as a 1-5 w/w% solution, which makes it an ideal disinfecting solution for closed space environments. Faraday has continued to improve the TRL by scaling the electrochemical peroxide generation system from a sub-scale to alpha-scale process in order to deliver 1 L per day of ~2 w/w% hydrogen peroxide for disinfectant applications from DI water feed-stream with air as a feed source[1],[2],[3],[4]. These electrolytes were then sent to NASA for microbial control property characterization.

This system eliminates the need to ferry disinfectant wipes to manned space capsules and is a critical enabling technology for future moon-based missions and beyond. Specifically, this talk will discuss the results of these advancements.

Acknowledgements: Financial support of NASA Contracts NNX16CA43P, NNX17CJ12C, 80NSSC20C0070, and 80NSSC23CA036 is acknowledged.

References:

[1] Vijapur, Santosh H., et al. "Electrochemical peroxide generation." ECS Transactions 77.11 (2017): 947.

[2] Vijapur, Santosh, et al. "In-Situ Resource Utilization for Electrochemical Generation of Hydrogen Peroxide for Disinfection." 49th International Conference on Environmental Systems, 2019.

[3] Nelson, George J., et al. "Electrochemistry for Space Life Support." The Electrochemical Society
Interface 29.1 (2020): 47.

[4] Vijapur, Santosh, et al. "In-Situ Resource Utilization for Electrochemical Generation of Hydrogen Peroxide for Disinfection." 50th International Conference on Environmental Systems, 2021.
(Invited) Some Observations on the History of Electrochemistry in Europe
Authors: Buckley Noel
Published: February 2024

Modern electrochemistry is generally regarded as having its origins in the work of the Italian scientists Galvani (1737 – 1798) and Volta (1745 – 1827). Their discoveries led directly to the invention (1799) by Volta of the voltaic pile, a primitive form of what we now call a battery. This invention greatly facilitated electrical experimentation and quickly led to a host of other electrochemical discoveries such as the electrolysis of water (Nicholson and Carlisle in 1800, although it was first demonstrated in 1789 by Deiman and van Troostwijk using an electrostatic generator), isolation of elemental alkali and alkaline earth metals (Davy, 1807–1808) and electroplating (Brugnatelli, 1805). The work of Davy (1778 – 1829) and of Faraday (1791 – 1867) greatly advanced the understanding of electrochemistry and Faraday’s laws of electrolysis (1833) put the field on a quantitative basis. This was followed by a long succession of electrochemical discoveries that has continued to the present.

Scientists such as Daniell (1790 – 1845), Grove (1811 – 1896), Leclanché (1839 – 1882) and Planté (1834 – 1889) made early improvements to batteries; of course, research and development of batteries remains an important area of electrochemistry. Historically, batteries were the primary source of electric current until practical electric dynamos became available in about 1870. Electroplating developed as a practical technology from about 1840, initially for electrodeposition of copper on printing plates. From 1893 to 1948, the international standard for electric current was based on electrodeposition of silver. Furthermore, an electrochemical cell invented by Weston (1850 – 1936) was adopted as the reference standard for voltage in 1903 and remained so until 1990 when it was replaced by a Josephson junction standard.

The science of electrochemistry experienced rapid growth from the 19th century on, with major contributions from European scientists including Kohlrausch (1840 – 1910), Ostwald (1853 – 1932), Arrhenius (1859 – 1927), Tafel (1862 – 1918), Nernst (1864 – 1941), and Heyrovský (1890 – 1967), to mention but a few. In this talk, I will attempt to trace the evolution of electrochemistry and discuss some of the major landmarks and the European scientists who made important contributions. I will also comment on how equipment and methodology have changed over the last half-century.
(Invited) Polymer Design for Beyond Lithium Ion Batteries
Authors: Bao Zhenan
Published: February 2024

In this talk, I will discuss our work related to polymer design for silicon anodes, S cathodes and polymer coating for lithium metal anodes.
(Invited) Improving Our Understanding of Conducting Polymer Binders
Authors: Kuss Christian , Mai Anh Ngoc Tram , Nguyen Van At , Odetallah Mariam , Lobato de Faria Marco
Published: February 2024

As lithium-ion batteries reach their intrinsic performance limits, next-generation battery technology arises that relies much more strongly on the electrode matrix. Traditional compositions of binders and conductive additives with non-polar surfaces face intrinsic obstacles in these developments. In many next-generation electrode formulations, this incompatibility reveals itself through particle disconnection, increased electrode inhomogeneity1, and conductive additive agglomeration2. Conducting polymers are an apparent solution to such problems. Conducting polymers and their composites can be designed to exhibit increased adhesion, stronger interactions with active material surfaces and electrolytes, and favorable mechanical properties, while providing electronic connectivity at the adhesive contact with the active material3. Many examples have been presented in the literature that demonstrate improved electrode performance using such composites4–6.

A common form of conducting polymer composites combines an intrinsically conductive polymer (e.g. polypyrrole, polythiophene, polyaniline) with a polyelectrolyte (e.g. polacrylate, polystyrene sulfonate, carboxymethyl cellulose). This presentation discusses an exploration of some of the fundamental properties of composites of polypyrrole with carboxymethyl cellulose. The work shows intrinsically favorable properties of the composite for application in batteries7. Among those properties are that it can be easily processed in water and N-methyl-2-pyrrolidone, exhibits better adhesion to the current collector, shows competitive conductivity and distributes evenly across active materials. However, it will also be shown that the native structure of this composite is not ideal for long-range conduction and that improvement can be made to the material’s conductivity and capacitance8.

Our work is targeting a more complete understanding of the properties of these composites as they are employed in battery environments. It demonstrates enormous promise for the use of conducting polymers as binders, but also gaps in our understanding of their interactions with electrolytes and active materials that need to be addressed to advance their impact on the development of next-generation batteries.

References:

Müller, S. et al.
Nat. Commun.
9, 2340 (2018).

Scipioni, R. et al.
J. Power Sources
307, 259–269 (2016).

Nguyen, V. A. & Kuss, C. J. Electrochem. Soc.
167, 065501 (2020).

Kim, J. M. et al.
ACS Appl. Mater. Interfaces
6, 12789–12797 (2014).

Salem, N., Lavrisa, M. & Abu-Lebdeh, Y. Energy Technol.
4, 331–340 (2016).

Higgins, T. M. et al.
ACS Nano
10, 3702–3713 (2016).

Nguyen, V. A., Wang, J. & Kuss, C. J. Power Sources Adv.
6, 100033 (2020).

Nguyen, V. A., Odetallah, M., Bakir, G., Gough, K. & Kuss, C. ACS Omega (2022).
(Invited) Electrochemically Active Materials: Meeting the High-Energy Density Challenge
Authors: Kumta Prashant Nagesh , Velikokhatnyi Oleg , Gaikwad Mayur , Kuruba Ramalinga , Blomgren George E
Published: February 2024

Energy storage is at a vantage state serving as the primary engine critical for an energy independent global economy currently still very much dependent on tapping into the earth’s natural reserves aided by natural oil and gas exports. The Li-ion battery chemistry has evolved over the years and is at the forefront of secondary rechargeable battery systems, witnessing burgeoning and ever-increasing research activity ever since Sony commercialized the first Li-ion battery in 1990. There have been since then transformative advances in all areas of cathodes, anodes, and electrolytes. Despite much progress, however, lithiated transition metal oxides and carbon remain the preferred typical systems that have made it into the commercial systems currently deployed in the hitherto electric vehicles (EVs). The intense research for identifying higher energy density systems has drawn the attention of Li-air and Li-S systems, of late. The Li-S systems are of particular interest due to the promise of achieving 500 Wh kg-1, a major milestone in meeting the energy density needed for next generation EVs matching and exceeding the performance metrics of the internal combustion engine (ICE).

This presentation will discuss the materials challenges that need to be overcome in generating high-energy density cathodes and anodes as well as electrolyte additives to reach the grand challenge of 500 Whkg-1. Research efforts made in the areas of developing cost-effective and scalable new sulfur confinement systems with ability to confine high sulfur loadings of 4-6 mg/cm2 enabling trapping the pernicious polysulfide species combined with unique functional electrocatalysts aided by theoretical first principles calculations exhibiting the propensity to catalyze the formation of Li2S will be discussed. In tandem, progress made in generating new dendrite-free anodes and low-density current collectors exhibiting areal capacities as high as 15 mAh/cm2 with stable cycling over 100 cycles as well as electrolyte additives matching the cathode performance will be outlined.
(Invited) Binder Investigation for Silicon Electrode of Lithium-Ion Batteries
Authors: Lu Wenquan , Salpekar Devashish , Zhang Linghong , Zhang Sanpei , Qin Yan , Kubal Joseph , Polzin Bryant , Trask Stephen E. , Meisner Quinton , Zhou Xinwei , Liu Yuzi , Zhang Zhengcheng , Jansen Andrew N.
Published: February 2024

Though the binder is not an active material and does not contribute capacity to lithium ion batteries (LIBs), it is an important ingredient for maintaining the integrity of the electrode, which helps to improve electrical contact between the active materials and conductive carbon black, improves the Li+ transport efficiency, reduces the internal resistance of Li-ion batteries and effectively depresses the crack formations and phase separation.

Polyvinylidene fluoride (PVDF) is a polymer that is commonly used as a binder for both anode and cathode materials in LIBs. However, it is not suitable for Si electrode due to its poor binding capability and stability. Viewed as a next generation anode material, Si has been extensively studied due to its extremely high theoretical specific capacity of 3578 mAh/g (assuming Li15Si4 as intermediate product). However, silicon undergoes huge volume variations during repeated discharge and charge, which requires a strong binder to maintain the electrode mechanical integrity. Developing a high strength binder for silicon anodes has been considered as an efficient pathway to alleviate various capacity decay pathways.

Polyacrylic acid (PAA) and its lithiated version (LiPAA), rich with carboxy function group, can provide stronger binding and are widely used as binder for Si electrode. In this work, we optimized Si electrode formulation by varying the binder composition. The optimized Si electrodes were electrochemically tested in both half cells and full cells. With improvement in electrochemical performance, cracks at the electrode level can still be observed for the cycled electrodes, which suggests that a stronger binder is required to mitigate volume expansion of Si electrodes and hold the particles together.

We further studied the polyimide (PI) materials as binders for Si anodes in an attempt to achieve more stable cycling performance. In this work, we explore various PI crosslinking conditions and their effects on electrochemical performance. The optimized silicon electrode exhibits a higher tensile strength than that of conventional PAA binder. The strong adhesion of the PI binder suppresses the structural collapse of the Si negative electrode during lithiation/delithiation, enabling good capacity retention and stable cycle life.
(Invited) Multifunctional Binders for High-Performance Rechargeable Batteries
Authors: Zhao Ran , Hu Zhifan , Lv Mengge , Wu Feng , Wu Chuan , Bai Ying
Published: February 2024

Secondary battery plays a significant role in our daily life as well as in modern smart grids, which typically consists of an electrolyte and two electrodes determining the key parameters of the battery. Despite a small dose that usually less than 10%, the binder is a crucial component to keep the electrode integrity and ensure the high electrochemical performance. What`s more, the modification of binder could be conducted to alleviate or even eliminate the side effects raised by failure behaviors of the electrode active materials. However, the state-of-the-art binder optimization strategies still fall behind the rapid development of the novel electrode materials.

To improve the energy density of secondary batteries, high-capacity electrode materials have been explored, including silicon, sulfur, layered oxides, etc. However, their practical applications are hindered by various failure behaviors. Take Si as an example, though the Si-based anodes exhibit high capacity up to 4200 mA g-1, they undergo huge volumetric expansion (≈400%) during the electrochemical reactions, resulting in the cracking of active material particles, electrode exfoliation, continuous electrolyte consumption and progressive SEI formation. As a consequence, the capacity of Si-based electrode decreases dramatically along with cycling. The conventional binders that have been widely used in the rechargeable battery systems are typically linear polymers, which are unable to endure the high volume change and address other challenges raised by electrode materials such as low conductivity, unstable bulk structure and interface, etc. To increase the mechanical strength and the electrochemical stability of electrodes, the design of multi-functional binders is considered to be an effective strategy to meet various requirements of advanced binders for high-performance batteries simultaneously.

In this work, the synthesis and characterization of multifunctional binders for high-capacity electrode materials are demonstrated. By the introduction of intermolecular forces and chemical bonds, 3D networks are constructed and the ability for volume change accommodation are enhanced as well as the binding force. Moreover, the dynamic crossed links also endow the binders with self-healing ability, which could help to remedy the cracking issues in the advanced electrode materials. Due to the merits of the as-synthesized binders, the electrochemcial performance of the high-capacity electrode is significantly improved, demonstrating a promising strategy for next-generation energy storage systems.
(Invited) Cation Conducting Binders: From Liquid to Solid-State Batteries
Authors: Popovic-Neuber Jelena
Published: February 2024

Binders play an important role in providing connection between active electrode materials with the conductive agent, thus enabling electronic/ionic pathways and good mechanical properties of battery electrodes.1 In the first part of my talk, I will discuss the case of binders for high volume expansion electrodes (e.g. Si), where cycle life is strongly reduced by cracking of active particles and solid electrolyte interphases (SEIs), the process which in turn consumes the electrolyte continuously. Here, development of multi-functional polymeric binders with ionic conductivity (and potentially self-healing functionalities) substituting the standard polyvinylidene fluoride (PVDF) has been of utmost importance.2,3 Consecutively, I will touch upon binder development from the process energy point of view, and discuss ionically conductive solvent-free binders, of relevance for future solid-state batteries containing highly reactive sulfide-based electrolytes.4 Finally, possibility of employment of fully inorganic polyphosphates and polysilicates binders will be investigated.5

F. Zou, A. Manthiram, Adv. Funct. Mater. 10, 45, 2002508 (2020)

J. Liu, Q. Zhang, T. Zhang, J.-T. Li, L. Huang, S.-G. Sun, Adv. Funct. Mater. 25, 23, 3599 (2015)

H. Liu, Q. Wu, X. Guan, M. Liu, F. Wang, R. Li, J. Xu, ACS Appl. Energy Mater. 5, 4, 4934 (2022)

S.-B. Hong, Y.-J. Lee, U.-H. Kim, C. Bak, Y. M. Lee, W. Cho, H. J. Hah, Y.-K. Sun, D.-W. Kim, ACS Energy Lett., 7, 3, 1092 (2022)

S. Trivedi, V. Pamidi, M. Fichtner, M. A. Reddy, Green Chem., 24, 5620 (2022)
(Invited) Functional Binder for Battery Electrode: Formation of Hierarchically Ordered Structures in Conductive Polymers to Enhance Ion and Electron Transport in the Electrode
Authors: Liu Gao
Published: February 2024

Electrode binder is a critical component for the successful engineering of modern lithium-ion rechargeable batteries. Electrode binder provides cohesion among the micron and nano size electrode particles, adhesion between particles and current collectors, and modulates particles volume changes during charge and discharge. The alloy material-based anode such as Si and Sn, is an attractive candidate for lithium-ion batteries and solid-state battery because it delivers much greater theoretical (e.g. Si at 4200 mAh/g) specific capacity than that of a traditional graphite anode material (∼370 mAh/g). However, the widespread application of silicon materials has remained a significant challenge because of the large volume change during lithium insertion and extraction processes, disrupting the electrode surface, electrode mechanical formation and cell integrity. The instabilities of the alloy materials lead to loss of the electrical contact in the electrode and increased parasitic reactions with electrolyte, causing the battery failure and significantly shorten the battery life. To address those challenges, multifunctional conductive polymers have been re-designed. In the conventional design of conductive polymers, organic functionalities are introduced via bottom-up synthetic approaches to enhance specific properties by modification of the individual polymers. Unfortunately, the addition of functional groups leads to conflicting effects, limiting their scaled synthesis and broad applications. Here we show a conductive polymer coating with simple primary building blocks that can be thermally processed to develop hierarchically ordered structures (HOS) with well-defined ordered morphologies. Our approach to constructing permanent HOS in conductive polymers leads to substantial enhancement of charge transport properties and mechanical robustness, which are critical for alloy material-based electrode and overall cell integrity.
(Invited) Organic Binders for Rechargeable Lithium Batteries
Authors: He Xin
Published: February 2024

Owing to the negative impact of the extensive utilization of batteries on the environment, sustainability of the cells needs to be included in the systemic research of batteries. Herein, a dissolvable ionic crosslinked polymer (DICP) is exploited as a binder for lithium–sulfur batteries by crosslinking the polyacrylic acid and polyethyleneimine through carboxy-amino ionic interaction. This interaction is pH-controlled, and therefore, the crosslinked binder network can be readily dissociated under basic conditions, providing a facile strategy enabling valuable components recycled through a convenient washing method. The sulfur cathode prepared using the recycled carbon–sulfur composite can deliver comparable capacity as that of fresh electrode. In addition, evidence from cell performance and characterizations, such as in situ X-ray absorption spectroscopy, in situ UV–visible spectroscopy, X-ray photoelectron spectroscopy, and density functional theory calculation, confirms that DICP is a more effective binder than its commercial counterpart on suppressing polysulfide dissolution in the electrolyte. Exploiting reversible crosslinked polymer binder for recyclable Li–S batteries with ameliorated electrochemical performance, this study illuminates sustainable development for large-scale energy storage systems.
Multifunctional Aqueous Binder for Cathode Processing
Authors: Sun Jinhua
Published: February 2024

To meet the critical requirements of the formation of robust and high-performance electrode, new binders with multifunction are highly desirable, especially for the next generation battery manufacturing, for example water-based cathode manufacturing. Here, as a single component, we combined water-based binder with highly conductive graphene with controllable density of the water-based binder on the surface of graphene. The as obtained binder shows good solubility and stability in water, decent conductivity, and tunable viscosity. The as obtained binder was mixed with standard NMC and LFP electrode for the water-based electrode processing. The formed electrode shows good adhesion with low loading of the binder. The binder and conductive additives are uniformly distributed in the formed electrode and covered the surface of cathode active materials surface. The NMC active material was modified with the resistance to be decomposed in the water. The electrode is not only stable under elevated temperature but also relatively high voltage, which is attributed to the presence of particular functional groups. The lithium-ion battery made by such aqueous binder shows comparable specific capacity and good stability as compare with the electrode prepared using PVDF binder and NMP solvent. The electrode after long term cycling was also investigated in order to understand the binder function during the charging/discharging process.
3D Fiber Network Enhanced Composite Polymer Electrolytes for All-Solid-State Sodium Batteries
Authors: Chen Suli , Che Haiying , Feng Fan , Ma Zi-Feng
Published: February 2024

All-solid-state sodium batteries (ASSBs) coupled with solid polymer electrolytes (SPEs) are considered a promising candidate for next generation energy-storage systems due to high energy-density, low-cost, and high-safety. However, the insufficient ionic conductivity and poor interfacial stability with Na metal anode of SPEs severely hinder their commercial applications. To tackle these issues, we designed a type of inorganic/polymer composite polymer electrolytes by dispersing the unique anion-trapping 3D fiber network with abundant Lewis-acid sites in the polymer matrix to realize ultra-stable ASSBs. The rich Lewis-acid sites exposed on the 3D fiber surface can grab anions to promote the dissociation of Na salts, thus significantly improve Na+ selective migrating ability. Meanwhile, the continuous channel formed between 3D fiber network and polymer matrix provides a fast Na+ transport path, further leading to high ionic conductivity. Importantly, the Na+ transference number can also be enhanced due to the anion-trapping effect, which will effectively limit anion migration, thus regulating Na+ concentration distribution for constructing stable electrolyte/Na anode interface. Based on such advantages, the resulting composite polymer electrolyte will simultaneously exhibit high ionic conductivity, considerable Na+ transference number, as well as enhanced interfacial stability toward Na metal anode. Consequently, the electrochemical properties, including discharge capacity, cycling stability, rate capability, and safety of all-solid state sodium batteries using these 3D fiber network enhanced composite polymer electrolytes will be remarkably improved. We believe that such a composite electrolyte design could provide an effective strategy for the construction of high safe and high energy-density all-solid-state rechargeable batteries.

Figure 1
Enhancing the Chemical Stability of Fluoride-Ion Batteries
Authors: Galatolo Giulia , Alshangiti Omar , Rees Gregory , Pasta Mauro
Published: February 2024

Fluoride-ion batteries (FIBs) are a promising post-lithium-ion technology that has the potential to achieve energy densities of >600 Wh/kg at the stack level and use Earth-abundant materials.1 These characteristics make them ideally suited to meet the requirements of the green energy transition. The progress of FIBs, however, has been hindered by the lack of a suitable liquid electrolyte as well as a reliable and practical electrochemical testing configuration. The chemical compatibility of solvent, salts as well as other inactive components in the presence of the highly reactive F-ion is often overlooked, resulting in the generation of HF, HF2
- or other by-products. For example, polyvinylidene fluoride (PVDF) is still the standard binder used in FIBs, despite its well-known chemical instability in the presence of F-ions.2 Moreover, most liquid FIBs are tested using flooded cells, where the large excess of electrolyte used and, the absence of a separator often underplay more fundamental issues such as electrolyte degradation and capacity fading.

In this work, we report a F-ion conducting liquid electrolyte with excellent chemical stability and good transport properties. We accomplish this, by combining an organic fluoride salt with an imidazolium-based ionic liquid, both free from β-hydrogens. We also adapt electrode dry-processing methods, widely used in lithium-ion batteries, to produce chemically stable Pb-PbF2 counter electrodes. Our results demonstrate that chemical stability and realistic testing conditions can be achieved in FIBs.

Xiao, A.W., Galatolo, G., Pasta, M.; The Case for Fluoride-ion Batteries. Joule
2021, 5, 2823–2844

Marshall, J.E.; On the Solubility and Stability of Polyvinylidene Fluoride. Polymers
2021, 13, 1354
Inhomogeneous Degradation in Lithium-Ion Batteries: The Effect of Thermal Gradients
Authors: Offer Gregory James , Li Shen , Zhang Cheng , Zhao Yan , Marinescu Monica
Published: February 2024

Understanding lithium ion battery degradation is a consequence of multiple, tightly coupled and non-linear degradation mechanisms. The interplay between these degradation mechanisms, and how the cell is used, gives rise to path dependent behaviour, and hence data driven approaches to model behaviour and predict lifetime rapidly become prohibitively expensive. Therefore, a physics based approach to model degradation is desirable.

In addition, all of the degradation mechanisms are a function of temperature, which adds another variable to the path dependency. To make matters worse, all cells experience internal thermal gradients during operation, which means the path dependency for different regions within a battery will be different. This leads to inhomogeneous degradation. After a few cycles, the degradation pathway of each region will then be affected not just by the thermal gradients and local current density but also by the state-of-health of that region, leading to complicated emergent behaviour.

Solving a physics based model with multiple degradation mechanisms, in a detailed 3-dimensional thermally coupled discretised model is also prohibitively expensive. Therefore, in this paper we present a thermally coupled distributed equivalent circuit model, with degradation functions built in, so each node can degrade at different rates, as a function of the operating conditions at that node. We have reproduced experimental data previously published, showing the effect of thermal gradients on degradation for two different cooling strategies for a tab and surface cooled pouch cell. For the first time reproducing the positive feedback mechanism responsible for accelerated degradation for surface cooling.

The results of this work show that thermal gradients cannot and should not be ignored, and degradation models that do not take them into account have a significant risk of overfitting and leading to incorrect conclusions.
Identifying Thermal Decomposition Mechanisms of the Solid Electrolyte Interphase with in-Situ Gas Analysis of Lithium-Ion Batteries
Authors: Schmidt Leon , Hankins Kie , Bläubaum Lars , Gerasimov Michail , Krewer Ulrike
Published: February 2024

The global shift away from fossil fuels has generated an unprecedented demand for electric vehicles and a steady increase in the prevalence of lithium-ion batteries. Additionally, increases in the energy density of storage technologies has led to a corresponding increase in safety concerns regarding thermal runaway reactions. The components of a lithium-ion battery can self-react when exposed to an external heat source, which can cause a thermal runaway reaction process and large-scale fires of the cell. The initial reactions in this process involve the decomposition of the Solid Electrolyte Interphase (SEI) breakdown and conductive salt. The underlaying mechanisms behind these reactions are unclear; in-depth investigations are needed in order to develop a detailed understanding of the thermal runaway process and guide the development of strategies to mitigate the safety hazards posed by these battery systems. In the past, differential/online electrochemical mass spectrometry (DEMS/OEMS) was utilized to analyze the buildup of the SEI as well as decomposition due to overcharge. Our new methodology of high temperature (HT-)OEMS, with a maximum temperature of 132 °C, can simulate heating events with thermal ramps on an in-situ test cell battery. These measurements reveal information regarding reaction product gases and cell voltage drop during first formation and thermal stress tests, and provide novel insight into the electrochemical and thermodynamic phenomena during thermal abuse of lithium-ion batteries.

In this study, we use (HT-)OEMS to investigate the behavior of lithium-ion cells with varied additive concentrations and formation currents. This new methodology allowed us to clearly determine that both of the testing parameters impact the formation gas evolution and thus influence the SEI-composition. Systems with high formation rates, as well as with lower concentrations of additives, exhibited an increase in the fraction of CO product gases, which can be explained with a higher presence of lithium alkoxides in the SEI. Additionally, the evolution of H2, CO2 and POF3 gases were observed at temperatures around 80 °C for cells during the thermal stress test after formation. These results allow us to establish a correlation between the thermal conductive salt decomposition and the formation of the SEI-components Li2CO3 and (CH2OLi)2.

The identification of the underlying degradation mechanisms and process correlations via (HT-)OEMS provides a novel and important understanding of the phenomena that give rise to thermal runaway in lithium-ion batteries. This cell chemistry-based insight can be used to guide future prevention-focused safety assessments.

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(Keynote) Rapid Thermal Management for Fast Charging of Energy-Dense Lithium-Ion Batteries
Authors: Wang Chao-Yang , Liu Teng , Yang Xiao-Guang , Ge Shanhai , Stanley Nathaniel V. , Rountree Eric S. , Leng Yongjun , McCarthy Brian D.
Published: February 2024

Charging time trauma refers to the pain experienced by electric vehicle (EV) owners when the ‘refill’ time is significantly longer than that of traditional internal combustion engine vehicles. Worsening this trauma is the inconsistency of EV charging; for example, the same EV may take five times longer to charge on a cold day. Faster charging will alleviate this pain point and aid in the mass adoption of EVs, crucial for meeting near-term carbon emission goals. Reaching this goal will require smarter and more rapid thermal management to provide significantly faster safe charging.

The results from the 2022 Nature article “Fast charging of energy-dense lithium-ion batteries” (DOI 10.1038/s41586-022-05281-0) where 265 Wh/kg lithium-ion pouch cells were charged from 0-70% in less than 12 minutes, 2,000 times in a row before end-of-life, will be presented. These cells used only proven materials, including a liquid electrolyte made from industrially-used components, and energy-dense, EV-grade electrodes. Key to success was smart cell thermal management. More recent advancements, including multi-cell battery-level data, will also be discussed.

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(Keynote) Thermo-Electrochemical Interactions in Solid-State Batteries
Authors: Mukherjee Partha P. , Vishnugopi Bairav Sabarish
Published: February 2024

Solid-state batteries (SSBs) with a lithium metal anode hold tremendous promise to enable long-range electric vehicles and electric aviation. However, the successful realization of practical SSBs necessitates gaining a fundamental understanding of the complex nature of solid-solid interface evolution including the origin of various failure/degradation mechanisms such as lithium filament penetration, void growth and interphase formation. While the influence of chemo-mechanics at such interfaces has received significant research attention, the underpinnings of thermo-electrochemical coupling and the thermal stability of solid-solid interfaces still require critical investigation. In this presentation, we mechanistically delineate the spatio-temporal attributes and implications of thermal interactions in SSBs, including their critical role on interface stability of the anode, electrochemical-transport response in the cathode and crosstalk between the cathode/solid-electrolyte/anode interfaces. The effect of architectural asymmetry in a solid-state cell, consisting of a heat-generating cathode and a lithium-metal anode, on the occurrence of an intrinsic thermal gradient and associated degradation modes have been highlighted. A comprehensive description of mechanisms underlying the thermo-electrochemical stability of solid-solid interfaces in SSBs is presented.
(Best Presentation Award - 2nd Place) Investigating Low Temperature Reaction Mechanisms of Alloy Anodes for Lithium-Ion Batteries
Authors: Cavallaro Kelsey Anne , Yoon Sun Geun , McDowell Matthew
Published: February 2024

Lithium-ion batteries (LIBs) are the battery of choice for most energy storage applications, including personal electronic devices and electric vehicles. However, poor low temperature performance, resulting from hindered solid state diffusion, slow desolvation kinetics, and dendrite formation, limits their use in nascent applications that require operation below -20 ºC, like electric aviation and space exploration. A small number of previous studies have shown that anode materials that electrochemically alloy with lithium ions can be cycled at temperatures as low as -40 ºC with significantly improved performance compared to graphite. Despite their improved low-temperature performance, reaction mechanisms and degradation behavior for these materials at low temperatures are poorly understood. This work aims to fill this gap in understanding by investigating the structural pathways during reactions of alloy anodes at low temperatures as well as characterizing their mechanical and electrochemical degradation. Electrode cross sectioning and scanning electron microscopy reveal that rapid capacity decay in antimony anodes at -40 ºC is a result of increased lithium trapping as well as particle fracture due to mechanical damage associated with volume change. We show that rapid capacity degradation of antimony at -40 ºC can be mitigated through the use of nanoscale particles. While nanoscale particles have been studied extensively at room temperature, little is known about they behave at low temperatures. Through SEM cross-sectioning and the galvanostatic intermittent titration technique (GITT), we show that the improvement in stability is likely due to faster kinetics related to the shorter diffusion length and increased mechanical stability resulting in less lithium trapping at low temperatures. Additionally, X-ray diffraction measurements were carried out as a function of temperature on micron- and nanosized antimony particles, as well as tin and graphite, to determine the composition and structure of lithiated phases formed at low temperatures. The results show that reduced temperatures alter phase transformation behavior in certain alloy materials. Overall, this work provides improved mechanistic understanding of alloy anodes at low temperatures, setting the stage for enhanced electrochemical performance.